WO2015025818A1 - Hydraulic control device for work machine - Google Patents

Hydraulic control device for work machine Download PDF

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Publication number
WO2015025818A1
WO2015025818A1 PCT/JP2014/071575 JP2014071575W WO2015025818A1 WO 2015025818 A1 WO2015025818 A1 WO 2015025818A1 JP 2014071575 W JP2014071575 W JP 2014071575W WO 2015025818 A1 WO2015025818 A1 WO 2015025818A1
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WIPO (PCT)
Prior art keywords
pressure
target
hydraulic
speed
unit
Prior art date
Application number
PCT/JP2014/071575
Other languages
French (fr)
Japanese (ja)
Inventor
宇田川　勉
石川　広二
中山　晃
枝穂 泉
亮平 山下
秀一 森木
Original Assignee
日立建機株式会社
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Publication of WO2015025818A1 publication Critical patent/WO2015025818A1/en

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    • E—FIXED CONSTRUCTIONS
    • E02—HYDRAULIC ENGINEERING; FOUNDATIONS; SOIL SHIFTING
    • E02F—DREDGING; SOIL-SHIFTING
    • E02F9/00—Component parts of dredgers or soil-shifting machines, not restricted to one of the kinds covered by groups E02F3/00 - E02F7/00
    • E02F9/20—Drives; Control devices
    • E02F9/22—Hydraulic or pneumatic drives
    • E02F9/2221—Control of flow rate; Load sensing arrangements
    • E02F9/2232—Control of flow rate; Load sensing arrangements using one or more variable displacement pumps
    • E02F9/2235—Control of flow rate; Load sensing arrangements using one or more variable displacement pumps including an electronic controller
    • E—FIXED CONSTRUCTIONS
    • E02—HYDRAULIC ENGINEERING; FOUNDATIONS; SOIL SHIFTING
    • E02F—DREDGING; SOIL-SHIFTING
    • E02F9/00—Component parts of dredgers or soil-shifting machines, not restricted to one of the kinds covered by groups E02F3/00 - E02F7/00
    • E02F9/20—Drives; Control devices
    • E02F9/22—Hydraulic or pneumatic drives
    • E02F9/2278—Hydraulic circuits
    • E02F9/2296—Systems with a variable displacement pump
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
    • F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
    • F15B11/00—Servomotor systems without provision for follow-up action; Circuits therefor
    • F15B11/16—Servomotor systems without provision for follow-up action; Circuits therefor with two or more servomotors
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
    • F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
    • F15B2211/00—Circuits for servomotor systems
    • F15B2211/20—Fluid pressure source, e.g. accumulator or variable axial piston pump
    • F15B2211/205—Systems with pumps
    • F15B2211/2053—Type of pump
    • F15B2211/20546—Type of pump variable capacity
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
    • F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
    • F15B2211/00—Circuits for servomotor systems
    • F15B2211/30—Directional control
    • F15B2211/31—Directional control characterised by the positions of the valve element
    • F15B2211/3138—Directional control characterised by the positions of the valve element the positions being discrete
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
    • F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
    • F15B2211/00—Circuits for servomotor systems
    • F15B2211/40—Flow control
    • F15B2211/405—Flow control characterised by the type of flow control means or valve
    • F15B2211/40515—Flow control characterised by the type of flow control means or valve with variable throttles or orifices
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
    • F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
    • F15B2211/00—Circuits for servomotor systems
    • F15B2211/40—Flow control
    • F15B2211/415—Flow control characterised by the connections of the flow control means in the circuit
    • F15B2211/41509—Flow control characterised by the connections of the flow control means in the circuit being connected to a pressure source and a directional control valve
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
    • F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
    • F15B2211/00—Circuits for servomotor systems
    • F15B2211/40—Flow control
    • F15B2211/42—Flow control characterised by the type of actuation
    • F15B2211/426—Flow control characterised by the type of actuation electrically or electronically
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
    • F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
    • F15B2211/00—Circuits for servomotor systems
    • F15B2211/40—Flow control
    • F15B2211/455—Control of flow in the feed line, i.e. meter-in control
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
    • F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
    • F15B2211/00—Circuits for servomotor systems
    • F15B2211/60—Circuit components or control therefor
    • F15B2211/63—Electronic controllers
    • F15B2211/6303—Electronic controllers using input signals
    • F15B2211/6306—Electronic controllers using input signals representing a pressure
    • F15B2211/6309—Electronic controllers using input signals representing a pressure the pressure being a pressure source supply pressure
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
    • F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
    • F15B2211/00—Circuits for servomotor systems
    • F15B2211/60—Circuit components or control therefor
    • F15B2211/63—Electronic controllers
    • F15B2211/6303—Electronic controllers using input signals
    • F15B2211/6336—Electronic controllers using input signals representing a state of the output member, e.g. position, speed or acceleration
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
    • F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
    • F15B2211/00—Circuits for servomotor systems
    • F15B2211/60—Circuit components or control therefor
    • F15B2211/63—Electronic controllers
    • F15B2211/6303—Electronic controllers using input signals
    • F15B2211/6346—Electronic controllers using input signals representing a state of input means, e.g. joystick position
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
    • F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
    • F15B2211/00—Circuits for servomotor systems
    • F15B2211/60—Circuit components or control therefor
    • F15B2211/665—Methods of control using electronic components
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
    • F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
    • F15B2211/00—Circuits for servomotor systems
    • F15B2211/60—Circuit components or control therefor
    • F15B2211/665—Methods of control using electronic components
    • F15B2211/6652—Control of the pressure source, e.g. control of the swash plate angle
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
    • F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
    • F15B2211/00—Circuits for servomotor systems
    • F15B2211/60—Circuit components or control therefor
    • F15B2211/665—Methods of control using electronic components
    • F15B2211/6654—Flow rate control

Definitions

  • the present invention relates to a hydraulic control device for a work machine that is provided in a work machine such as a hydraulic excavator and is suitable for driving the work machine by discharging hydraulic oil from a hydraulic pump to a plurality of hydraulic actuators.
  • a work machine such as a hydraulic excavator or a wheel loader includes a plurality of hydraulic actuators such as hydraulic cylinders that are operated by hydraulic oil discharged as pressure oil from a hydraulic pump, and an operation device that operates these hydraulic actuators.
  • the hydraulic oil is distributed to the hydraulic actuators according to the operation input of the operating device, so that the turning operation of the turning body and the turning operation of the boom and the like are performed in a composite manner.
  • this ultra-small swivel hydraulic working machine of the prior art includes a hydraulic pump and a plurality of hydraulic actuators such as a swing motor and a boom cylinder, as well as hydraulic fluid discharged from the hydraulic pump to each hydraulic actuator.
  • a directional control valve for controlling the flow, a pressure compensation valve for controlling the pressure of hydraulic oil discharged from the hydraulic pump to each hydraulic actuator, and the discharge pressure of the hydraulic pump and the load pressure of each hydraulic actuator are set to a predetermined differential pressure.
  • a pump capacity control cylinder to be maintained and a discharge amount control unit such as a load sensing valve are provided.
  • the pressure compensation valve keeps the differential pressure before and after the directional control valve constant, and the discharge amount control unit is higher than the load pressure of the highest hydraulic actuator among the multiple hydraulic actuators by the target differential pressure, that is, the load sensing differential pressure.
  • each operation part driven by each hydraulic actuator has its own weight, the inertial mass of the work object, and the load due to the reaction force received from the work object.
  • the same characteristics as described above are not always required for the part.
  • a bucket having a relatively high speed controllability is relatively preferred, but a swinging device, a boom, etc. preferably have a good force controllability in addition to the speed controllability.
  • the conventional ultra-small swivel hydraulic working machine is one in which an operator operates each operating part by operating an operating device, so that even if it has excellent speed controllability, force controllability is obtained. Otherwise, it is required to operate carefully so that the revolving body and boom do not suddenly start or stop suddenly, and there is a concern that the operating performance of the operating device will deteriorate.
  • the flow rate controllability of hydraulic fluid flowing into each hydraulic actuator of a work machine to which a load sensing system is applied is a directional control valve based on an operation input of an operating device. This is determined by the response of the spool and the pressure control response of the pressure compensation valve. Therefore, if there is no dynamic delay in the operation of the spool of the directional control valve with respect to the operation input of the operating device, the flow rate controllability of the hydraulic oil is determined by the pressure control response of the pressure compensation valve.
  • the valve has a characteristic of quickly following the speed of each hydraulic actuator. Therefore, if the response of the pressure control of the pressure compensation valve can be freely set and the operation of the pressure control valve can be delayed with respect to the speed of each hydraulic actuator, it is considered that the operation performance of the operating device can be improved.
  • the following characteristics of the pressure compensation valve are composed of components such as the force acting on the pressure receiving portion of the pressure compensation valve, the elastic force of the spring acting on the pressure compensation valve, the mass of the pressure compensation valve, and the pressure transmission circuit.
  • the pressure compensation valve operates quickly with respect to the speed of each hydraulic actuator by such a hardware configuration that cannot be changed easily, so that the pressure control response of the pressure compensation valve can be freely set It is difficult to improve the operating performance of the operating device.
  • the present invention has been made based on the actual situation of the prior art as described above, and its object is to sufficiently improve the force controllability while ensuring the speed controllability of the hydraulic actuator with respect to the operation input of the operation device.
  • An object of the present invention is to provide a hydraulic control device for a working machine.
  • a hydraulic control device for a work machine includes a hydraulic pump driven by a prime mover, a plurality of hydraulic actuators operated by hydraulic oil discharged from the hydraulic pump, and the hydraulic pressures thereof.
  • a hydraulic control unit that is provided in a work machine including an operation device that operates an actuator, and that controls an operation flow from the hydraulic pump to the plurality of hydraulic actuators in response to an operation input from the operation device;
  • a discharge pressure detection unit that detects a discharge pressure of the hydraulic pump
  • a speed detection unit that detects a speed of the plurality of hydraulic actuators, and a hydraulic fluid flowing into the plurality of hydraulic actuators
  • a plurality of hydraulic actuators based on an inflow control unit for controlling pressure and an operation amount operated by the operation device.
  • a plurality of hydraulic actuators based on the target speed calculation unit that calculates a target value of the speed at which the motor is operated, the speed detected by the speed detection unit, and the target value calculated by the target speed calculation unit A target driving pressure calculating unit that calculates a target value of a driving pressure for driving the hydraulic pressure, and the hydraulic pressure according to the discharge pressure detected by the discharge pressure detecting unit and the target value calculated by the target driving pressure calculating unit.
  • a target discharge amount calculation unit that calculates a target value of the pump discharge amount, and the inflow control unit flows into the plurality of hydraulic actuators according to the target value calculated by the target drive pressure calculation unit While controlling the pressure of hydraulic fluid, the hydraulic control unit controls the discharge amount of the hydraulic pump to the target value calculated by the target discharge amount calculation unit. It is characterized.
  • the target speed calculation unit calculates the target value of the speed for operating each hydraulic actuator based on the operation amount operated by the operation device.
  • the target drive pressure calculator calculates the detected speed of each hydraulic actuator and the target calculated by the target speed calculator. Based on the value, the target value of the driving pressure of each hydraulic actuator can be calculated.
  • the discharge pressure detection unit detects the discharge pressure of the hydraulic pump
  • the discharge amount calculation unit according to the detected discharge pressure of the hydraulic pump and the target value calculated by the target drive pressure calculation unit, The target value of the discharge amount of the hydraulic pump is calculated, and the hydraulic control unit controls the discharge amount of the hydraulic pump to the calculated target value.
  • hydraulic oil having a flow rate corresponding to this target value is discharged as pressure oil from the hydraulic pump toward each hydraulic actuator into the hydraulic circuit, so that the discharged hydraulic oil is arranged upstream of each hydraulic actuator. Flow into the inflow control unit.
  • each hydraulic actuator can be appropriately operated. Therefore, the force controllability can be sufficiently improved while ensuring the speed controllability of the hydraulic actuator with respect to the operation input of the operation device.
  • the hydraulic control device for a work machine further includes a pressure limiting unit that sets an upper limit pressure of the driving pressure based on the operation amount operated by the operating device, and the target driving pressure calculation
  • the unit is configured to determine the driving pressure based on the speed detected by the speed detecting unit, the target value calculated by the target speed calculating unit, and an upper limit pressure of the driving pressure set by the pressure limiting unit. It is characterized by calculating a target value.
  • the drive pressure required for each hydraulic actuator to obtain the target value speed calculated by the target speed calculation unit with respect to the operation amount of the operating device is set by the pressure limiting unit. Since the pressure exceeding the upper limit of the drive pressure does not act on each hydraulic actuator even when the upper limit is exceeded, the driving force of each hydraulic actuator depends on the operation amount of the operating device. Can be suppressed, and high force controllability can be obtained.
  • the driving pressure required for each hydraulic actuator to obtain the target speed calculated by the target speed calculator with respect to the operation amount of the operating device is the upper limit pressure of the driving pressure set by the pressure limiter.
  • the drive pressure of the hydraulic actuator is not limited and the drive force of each hydraulic actuator is not suppressed in the calculation process of the target drive pressure calculation unit, excellent speed controllability can be obtained.
  • the target drive pressure calculation unit uses the target discharge amount as a calculation result that is a value lower than the target value of the calculated drive pressure by a predetermined value. It is characterized by being output to a calculation unit.
  • the discharge pressure of the hydraulic pump is lower by a predetermined value than the drive pressure of the hydraulic actuator for which the highest target value has been calculated by the target drive pressure calculation unit among the plurality of hydraulic actuators.
  • the inflow control unit that controls the driving pressure of the engine can maximize the opening area, and can minimize resistance generated when hydraulic fluid passes, that is, pressure loss.
  • the relationship between the operation amount operated by the operation device and the target value calculated by the target speed calculation unit is stored in advance.
  • a relationship correction unit that corrects the relationship stored in the storage unit according to the target value calculated by the target drive pressure calculation unit, and the target speed calculation unit is corrected by the relationship correction unit.
  • the target value is calculated by applying the operation amount operated by the operation device to the relationship.
  • the relationship correction unit is stored in the storage unit.
  • the target value of the speed of each hydraulic actuator can be obtained with respect to the operation amount of the operating device. Thereby, the operation feeling of the operating device can be easily adjusted for each hydraulic actuator.
  • the inflow control unit is provided between the hydraulic pump and the plurality of hydraulic actuators, and controls the pressure of hydraulic fluid that passes therethrough. It includes a control valve, and the pressure control valve is driven by receiving an input signal from the outside, and the opening amount is decreased as the input signal increases.
  • the hydraulic control unit is configured to generate a target drive pressure based on the speed of each hydraulic actuator detected by the speed detection unit and the target value of the speed calculated by the target speed calculation unit.
  • the pressure corresponding to the target value calculated by the calculation unit can be appropriately applied to each hydraulic actuator via the inflow control unit by adjusting the discharge amount of the hydraulic pump by the target discharge amount control unit. Therefore, the driving force of each hydraulic actuator can be suppressed according to the operation amount of the operating device, and the force controllability is sufficiently improved while ensuring the speed controllability of the hydraulic actuator for the operation input of the operating device. be able to. Accordingly, stable operation of each hydraulic actuator can be realized, and a smooth operation feeling can be obtained. Therefore, the operation performance of the operation device can be improved, and the work efficiency of the work machine can be improved as compared with the conventional case.
  • FIG. 3 It is a figure showing a hydraulic excavator mentioned as an example of a working machine with which a 1st embodiment of a hydraulic control device concerning the present invention is provided. It is a figure showing composition of a 1st embodiment of a hydraulic control device of a working machine concerning the present invention. It is a figure which shows the structure of the controller with which 1st Embodiment of this invention was equipped. It is a figure which shows the principal part of the controller shown in FIG. 3, and is a figure explaining each functional relationship of the target speed table regarding an especially turning motor, and an upper limit pressure table. It is a figure which shows the principal part of the controller shown in FIG. 3, and is a figure explaining each function relationship of the target speed table and upper limit pressure table regarding especially a boom cylinder.
  • a figure shows the structure of the electromagnetic proportional pressure reducing valve which comprises an inflow control part
  • the figure is an electromagnetic proportional pressure reduction. It is a figure which shows the characteristic of a valve. It is a figure which shows the structure of the controller with which 2nd Embodiment of this invention was equipped. It is a figure explaining the functional relationship of the target speed table regarding the turning motor correct
  • a figure shows the structure of the electromagnetic proportional throttle valve which comprises an inflow control part
  • the figure is an electromagnetic proportional throttle It is a figure which shows the characteristic of a valve. It is a figure which shows the structure of the controller with which 3rd Embodiment of this invention was equipped.
  • the first embodiment of the hydraulic control apparatus according to the present invention is applied to a work machine, for example, a hydraulic excavator 1 shown in FIG.
  • the hydraulic excavator 1 includes a traveling body 2, a revolving body 3 attached to the upper side of the traveling body 2 via a revolving device 3A, and a revolving body 3 mounted in front of the revolving body 3 so as to rotate in the vertical direction.
  • the front work machine 4 is configured.
  • the front work machine 4 includes a boom 4A whose base end is pivotally attached to the swing body 3 and pivots in the vertical direction, an arm 4B pivotally attached to the tip of the boom 4A, and the arm And a bucket 4C rotatably attached to the tip of 4B.
  • the swivel body 3 is arranged at the front, a cab 7 disposed at the rear, a counterweight 6 disposed at the rear to maintain the balance of the vehicle body, and disposed between the cab 7 and the counterweight 6, and an engine 11 (see FIG. 2) and an engine speed detector 11A (see FIG. 2) that is attached to the engine 11 in the engine room 5 and detects the speed of the engine 11.
  • the rotating body 3 is rotated by a driving force of the engine 11, and a variable displacement swash plate hydraulic pump (hereinafter referred to as hydraulic pressure for convenience) that discharges hydraulic oil as pressure oil for driving the front work machine 4.
  • a pump a tilt amount adjusting unit 12 A that adjusts the tilt amount by changing the tilt angle of a swash plate (not shown) with respect to the rotating shaft of the hydraulic pump 12, and the hydraulic pump 12
  • hydraulic oil tank 13 that stores the hydraulic oil to be sucked in and a plurality of hydraulic actuators that are operated by the hydraulic oil discharged from the hydraulic pump 12.
  • the hydraulic pump 12 is not limited to the swash plate type, and other variable displacement mechanisms such as a swash shaft type may be used.
  • These hydraulic actuators are arranged on the upper side of the boom 4A, for example, a swing motor 3a that drives the swing device 3A, a swing cylinder 3 that connects the swing body 3 and the boom 4A, and rotates the boom 4A by extending and contracting.
  • a swing motor 3a that drives the swing device 3A
  • a swing cylinder 3 that connects the swing body 3 and the boom 4A
  • rotates the boom 4A by extending and contracting At the same time, the boom cylinder 4A and the arm 4B are connected, and the arm cylinder 4b that rotates the arm 4B by extending and contracting, and the bucket cylinder that connects the arm 4B and the bucket 4C and rotating the bucket 4C by expanding and contracting. 4c.
  • the swing body 3 is connected between the hydraulic pump 12 and each swing motor 3a, the boom cylinder 4a, the arm cylinder 4b, and the bucket cylinder 4c, and controls the flow of hydraulic oil discharged from the hydraulic pump 12.
  • Control valves 16A to 16D are provided.
  • Each of the directional control valves 16A to 16D is, for example, a closed center type having no center bypass oil passage and does not include a bleed-off circuit.
  • the cab 7 includes an operation seat (not shown) on which an operator is seated, and an operation device that is provided in the vicinity of the operation seat and operates each of the hydraulic actuators 3a, 4a to 4c.
  • a left operation lever 15A that is disposed on the left side of the driver's seat and that rotates the swivel device 3A to the left or right, or that rotates the arm in the vertical direction.
  • a pilot pump (not shown).
  • the left operation lever 15A is connected to, for example, the left and right pressure receiving chambers of the directional control valve 16A on the swing motor 3a side.
  • the pressure of pilot pressure oil supplied to each pressure receiving chamber of the direction control valve 16A, that is, the pilot pressure is adjusted according to the amount of operation and received, and the pilot pressure is applied to the direction control valve 16A to change the switching position of the direction control valve 16A. I try to switch.
  • the left operation lever 15A is connected to, for example, the left and right pressure receiving chambers of the direction control valve 16C on the arm cylinder 4b side, and the pilot pressure oil guided from the pilot pump is operated in the front / rear direction among the front / rear and left / right directions.
  • the pilot pressure supplied to each pressure receiving chamber of the direction control valve 16C is adjusted according to the operation amount, and the pilot pressure is applied to the direction control valve 16C to switch the switching position of the direction control valve 16C. . Therefore, the operator rotates the arm 4B in the vertical direction by operating the left operation lever 15A in the left-right direction to turn the turning device 3A in the left-right direction, or operating the left operation lever 15A in the front-rear direction. Can be moved.
  • the right operation lever 15B is connected to the left and right pressure receiving chambers of the direction control valve 16B on the boom cylinder 4a side, for example, and inputs pilot pressure oil guided from the pilot pump in the front / rear direction among the front / rear and left / right directions.
  • the pilot pressure supplied to each pressure receiving chamber of the direction control valve 16B is adjusted according to the amount of operation received, and the pilot pressure is applied to the direction control valve 16B to switch the switching position of the direction control valve 16B.
  • the right operation lever 15B is connected to, for example, the left and right pressure receiving chambers of the direction control valve 16D on the bucket cylinder 4c side, and adjusts the pilot pressure supplied to each pressure receiving chamber of the direction control valve 16D according to the operation amount.
  • the pilot pressure is applied to the direction control valve 16D to switch the switching position of the direction control valve 16D. Therefore, the operator operates the right operation lever 15B in the front-rear direction to rotate the boom 4A in the vertical direction, or operates the right operation lever 15B in the left-right direction to move the bucket 4C in the vertical direction. It can be rotated.
  • the operation amount of each operation lever 15A, 15B is a positive value when, for example, the operation direction is the left direction or the front direction, and is negative when the operation direction of each operation lever 15A, 15B is the right direction or the rear direction. Value.
  • the left operation lever 15A and the right operation lever 15B are provided with operation amount sensors 15A1 and 15B1 as operation amount detection units for detecting an operation amount, respectively.
  • the pilot pressure of the pilot pressure oil supplied from the levers 15A and 15B to the pressure receiving chambers of the direction control valves 16A to 16D is detected as an operation amount.
  • a discharge pressure sensor 17 serving as a discharge pressure detection unit for detecting the discharge pressure of the hydraulic pump 12 is provided in a pipe line connecting the directional control valves 16A to 16D and the hydraulic pump 12.
  • Speed sensors 18A to 18D as speed detectors for detecting the speeds of the hydraulic actuators 3a and 4a to 4c
  • inflow control for controlling the pressure of hydraulic oil flowing into the hydraulic actuators 3a and 4a to 4c, that is, driving pressure.
  • the first embodiment of the present invention is a hydraulic control unit that controls the flow rate of hydraulic oil discharged from the hydraulic pump 12 to the hydraulic actuators 3a, 4a to 4c in response to operation inputs from the operation levers 15A and 15B.
  • the controller 20 is connected to operation amount sensors 15A1 and 15B1, a discharge pressure sensor 17, speed sensors 18A to 18D, a tilt amount adjustment unit 12A, and inflow control units 19A to 19D. Yes.
  • the configuration of the controller 20 according to the first embodiment of the present invention will be described in detail with reference to FIG. 3, but the control of the arm cylinder 4b and the bucket cylinder 4c is performed similarly to the control of the boom cylinder 4a. A description of the configuration and operation related to the control of the arm cylinder 4b and the bucket cylinder 4c is omitted.
  • the controller 20 sets a target value (hereinafter referred to as a convenience) of a speed at which the turning motor 3a is operated based on an operation amount operated by the left operation lever 15A, that is, an operation amount detected by the operation amount sensor 15A1. (Referred to as a target turning speed) and a driving pressure for driving the turning motor 3a based on the operation amount operated by the operation amount sensor 15A1 (hereinafter referred to as a turning driving pressure for convenience).
  • Pressure limiter 25A2 for setting the upper limit pressure
  • the speed of the swing motor 3a detected by the speed sensor 18A the target swing speed calculated by the target speed calculator 25A1, and the swing set by the pressure limiter 25A2.
  • the target value of the drive pressure of the swing motor 3a (hereinafter referred to as the target swing drive pressure for convenience). And a target driving pressure calculating section 26A for calculating a.
  • the pressure limiter 25A2 may be omitted regardless of whether the pressure limiter 25A2 is included.
  • the controller 20 Based on the operation amount operated by the right operation lever 15B, that is, the operation amount detected by the operation amount sensor 15B1, the controller 20 sets a target value of the speed for operating the boom cylinder 4a (hereinafter referred to as a target boom speed for convenience).
  • the upper limit pressure of the driving pressure for driving the boom cylinder 4a (hereinafter referred to as the boom driving pressure for convenience) is determined based on the operation amount detected by the target speed calculation unit 25B1 and the operation amount sensor 15B1.
  • the speed limit unit 25B2 to be set, the speed of the boom cylinder 4a detected by the speed sensor 18B, the target boom speed calculated by the target speed calculation unit 25B1, and the upper limit pressure of the boom drive pressure set by the pressure limit unit 25B2 Based on the target value of the drive pressure of the boom cylinder 4a (hereinafter, the target boom drive And a target driving pressure calculating unit 26B for calculating referred to as pressure).
  • the pressure limiter 25B2 may be omitted regardless of whether the pressure limiter 25B2 is included.
  • the controller 20 discharges the hydraulic pump 12 according to the discharge pressure of the hydraulic pump 12 detected by the discharge pressure sensor 17 and the target swing drive pressure and target boom drive pressure calculated by the target drive pressure calculation units 26A and 26B.
  • a target discharge amount calculation unit 30 for calculating a target value of the amount (hereinafter referred to as a target discharge amount for convenience) is provided.
  • inflow control part 19A, 19B is the pressure of the hydraulic fluid which flows in into each turning motor 3a and boom cylinder 4a according to the target turning drive pressure and target boom drive pressure which were calculated by target drive pressure calculating part 26A, 26B. That is, the controller 20 controls the drive pressure and sets the flow rate according to the drive pressure, and the controller 20 controls the discharge amount of the hydraulic pump 12 to the target discharge amount calculated by the target discharge amount calculation unit 30. Yes.
  • the inflow control units 19A and 19B set the flow rates of the hydraulic oil flowing into the swing motors 3a and the boom cylinders 4a, the directional control valves 16A and 16B are connected to the actuators 3a and 4a.
  • the main function is to switch the direction of hydraulic oil outflow, and the throttle function for setting the flow rate for each actuator 3a, 4a of the normal directional control valve reduces the influence.
  • target speed calculation units 25A1, 25B1, pressure limiting units 25A2, 25B2, target drive pressure calculation units 26A, 26B, target discharge amount calculation unit 30, and inflow control units 19A, 19B according to the first embodiment of the present invention.
  • the specific configuration of will be described.
  • a target speed table 25a1 shown in FIG. 4 is stored in advance as the relationship between the operation amount operated by the left operation lever 15A and the target turning speed calculated by the target speed calculation unit 25A1.
  • a storage unit 25a3 is provided, and this storage unit 25a3 is stored, for example, inside the target speed calculation unit 25A1.
  • the functional relationship of the target speed table 25a1 has a minimum value VRmin and a maximum value VRmax, and the absolute value of the slope of the target turning speed VR with respect to the operation amount XL increases stepwise as the absolute value of the operation amount XL increases. It is set to be.
  • the target speed calculation unit 25A1 calculates the target turning speed by applying the operation amount detected by the operation amount sensor 15A1 to the functional relationship of the target speed table 25a1 set in this way.
  • an upper limit pressure table 25a2 shown in FIG. 4 is previously stored as the relationship between the operation amount operated by the left operation lever 15A and the upper limit pressure of the turning drive pressure set by the pressure limiting unit 25A2.
  • the storage unit 25a4 is stored, and the storage unit 25a4 is stored, for example, inside the pressure limiting unit 25A2.
  • the functional relationship of the upper limit pressure table 25a2 has a minimum value PRmin (> 0) and a maximum value PRmax, and the slope of the upper limit pressure PR of the swing drive pressure with respect to the operation amount XL increases as the absolute value of the operation amount XL increases.
  • the absolute value is set to increase stepwise.
  • the pressure limiter 25A2 sets the upper limit pressure of the turning drive pressure by applying the operation amount detected by the operation amount sensor 15A1 to the functional relationship of the upper limit pressure table 25a2 set in this way.
  • the target drive pressure calculator 26A is configured to perform proportional control, differential control, based on the deviation between the speed of the swing motor 3a detected by the speed sensor 18A and the target swing speed calculated by the target speed calculator 25A1, that is, the speed deviation.
  • a PID control unit 26A1 that performs PID control combined with integral control, and a turning drive connected to the PID control unit 26A1 and the pressure limiting unit 25A2 and set by the pressure limiting unit 25A2 with respect to the output value of the PID control unit 26A1
  • a limiter processing unit 26A2 for performing a limiter process for limiting the upper limit pressure.
  • the PID controller 26A1 eliminates the speed deviation by performing PID control on the speed of the swing motor 3a detected by the speed sensor 18A and the target swing speed calculated by the target speed calculator 25A1, that is, the swing motor.
  • the turning driving pressure required to make the speed 3a coincide with the target turning speed is calculated and output to the limiter processing unit 26A2.
  • the PID control unit 26A1 uses PID control, but any control method can be used as long as the output value can follow the target value, and the PID control unit 26A1 is not limited to PID.
  • the limiter processing unit 26A2 compares the turning drive pressure calculated by the PID control unit 26A1 with the upper limit pressure of the turning drive pressure set by the pressure limiting unit 25A2, and the turning drive pressure calculated by the PID control unit 26A1 is the pressure. If the upper limit pressure of the turning drive pressure set by the restriction unit 25A2 is greater than the upper limit pressure of the turning drive pressure, the calculation is performed with the upper limit pressure of the turning drive pressure set by the pressure restriction unit 25A2 as the target turning drive pressure.
  • the limiter processing unit 26A2 determines the swing drive pressure calculated by the PID control unit 26A1 if the swing drive pressure calculated by the PID control unit 26A1 is equal to or lower than the upper limit pressure of the swing drive pressure set by the pressure limiting unit 25A2. Is calculated to be a target turning drive pressure. Note that the maximum value PRmax of the upper limit pressure of the turning drive pressure described above is set to be larger than the turning drive pressure calculated by the PID control unit 26A1.
  • the limiter processing unit 26A2 outputs the calculated target turning drive pressure as a command current to the inflow control unit 19A, and calculates a target discharge amount as a calculation result that is a predetermined value, for example, 1 MPa lower than the calculated target turning drive pressure. The data is output to the calculation unit 30. The reason for using the predetermined value will be described later. When this calculation result becomes a negative value, the limiter processing unit 26A2 regards it as 0 MPa and outputs it to the target discharge amount calculation unit 30.
  • a target speed table 25b1 shown in FIG. 5 is used as the relationship between the operation amount operated by the right operation lever 15B and the target boom speed calculated by the target speed calculation unit 25B1.
  • the storage unit 25b3 is stored in advance, and the storage unit 25b3 is stored in, for example, the target speed calculation unit 25B1.
  • the target speed table 25b1 of the target speed calculation unit 25B1 has a functional relationship in which the target boom speed VB increases as the operation amount XR increases, and this functional relationship indicates that the boom 4A is rotated with respect to the turning operation of the boom 4A. Since the required performance differs depending on the operation direction such as raising and lowering the boom 4A, it is set according to the operation direction and the operation amount of the right operation lever 15B.
  • the target speed table 25b1 has a minimum value VBmin and a maximum value VBmax so that the absolute value of the gradient of the target boom speed VB with respect to the operation amount XR increases stepwise as the absolute value of the operation amount XR increases. It has become.
  • the target speed calculation unit 25B1 calculates the target boom speed by applying the operation amount detected by the operation amount sensor 15B1 to the functional relationship of the target speed table 25b1 set in this way.
  • an upper limit pressure table 25b2 shown in FIG. 5 is previously stored as the relationship between the operation amount operated by the right operation lever 15B and the upper limit pressure of the boom drive pressure set by the pressure limiting unit 25B2.
  • the storage unit 25b4 is stored, and the storage unit 25b4 is stored, for example, inside the pressure limiting unit 25B2.
  • the upper limit pressure table 25b2 of the pressure limiting unit 25B2 has a functional relationship in which the upper limit pressure PB of the boom driving pressure increases as the absolute value of the operation amount XR increases. This functional relationship is the rotation of the boom 4A as described above. Since the required performance differs depending on the operation direction such as raising the boom 4A and lowering the boom 4A with respect to the moving operation, the setting is set according to the operation direction and the operation amount of the right operation lever 15B.
  • the line target is set.
  • the functional relationship of the upper limit pressure table 25b2 has a minimum value PBmin (> 0) and a maximum value PBmax, and the gradient of the upper limit pressure PB of the boom drive pressure with respect to the operation amount XR is stepped as the absolute value of the operation amount XR increases. Is set to increase.
  • the pressure limiting unit 25B2 sets the upper limit pressure of the boom driving pressure by applying the operation amount detected by the operation amount sensor 15B1 to the functional relationship of the upper limit pressure table 25b2 set in this way.
  • the target drive pressure calculator 26B performs proportional control, differential control, and integral control based on the deviation between the speed of the boom cylinder 4a detected by the speed sensor 18B and the target boom speed calculated by the target speed calculator 25B1.
  • a PID control unit 26B1 that performs combined PID control, and an upper limit pressure of the boom drive pressure that is connected to the PID control unit 26B1 and the pressure limiting unit 25B2 and set by the pressure limiting unit 25B2 with respect to the output value of the PID control unit 26B1
  • a limiter processing unit 26B2 for performing a limiter process for adding the above limitation.
  • the PID control unit 26B1 eliminates the speed deviation by performing PID control on the speed of the boom cylinder 4a detected by the speed sensor 18B and the target boom speed calculated by the target speed calculation unit 25B1, that is, the boom cylinder
  • the boom driving pressure required to match the speed 4a with the target boom speed is calculated and output to the limiter processing unit 26B2.
  • the PID control unit 26B1 uses PID control, but any control method can be used as long as the output value can follow the target value, and the PID control unit 26B1 is not limited to PID.
  • the limiter processing unit 26B2 compares the boom driving pressure calculated by the PID control unit 26B1 with the upper limit pressure of the boom driving pressure set by the pressure limiting unit 25B2, and the boom driving pressure calculated by the PID control unit 26B1 is the pressure. If the upper limit pressure of the boom drive pressure set by the limiter 25B2 is greater than the upper limit pressure of the boom drive pressure, the calculation is performed with the upper limit pressure of the boom drive pressure set by the pressure limiter 25B2 as the target boom drive pressure.
  • the limiter processing unit 26B2 may calculate the boom driving pressure calculated by the PID control unit 26B1. -Calculates the target boom drive pressure. Further, the limiter processing unit 26B2 outputs the calculated target boom driving pressure as a command current to the inflow control unit 19B, and calculates a target discharge amount as a calculation result that is a predetermined value, for example, 1 MPa lower than the calculated target boom driving pressure. The data is output to the calculation unit 30. When the calculation result becomes a negative value, the limiter processing unit 26B2 regards it as 0 MPa and outputs it to the target discharge amount calculation unit 30.
  • the target discharge amount calculation unit 30 is based on an input value input from the limiter processing unit 26A2 and an input value input from the limiter processing unit 26B2.
  • a target discharge pressure calculation unit selects the maximum target discharge pressure as the target discharge pressure of the hydraulic pump 12 by selecting the larger one of the input value input from the limiter processing unit 26A2 and the input value input from the limiter processing unit 26B2, for example. It consists of part 30A.
  • the target discharge amount calculation unit 30 is, for example, similar to the PID control units 26A1 and 26B1 described above, the discharge pressure of the hydraulic pump 12 detected by the discharge pressure sensor 17 and the hydraulic pump 12 selected by the maximum target discharge pressure selection unit 30A.
  • a PID control unit 30B that performs PID control based on a deviation from the target discharge pressure, and a target discharge amount correction unit 30C that corrects the output value of the PID control unit 30B with the rotational speed of the engine 11. Yes.
  • the PID control unit 30B performs hydraulic pressure control by performing PID control on the discharge pressure of the hydraulic pump 12 detected by the discharge pressure sensor 17 and the target discharge pressure of the hydraulic pump 12 calculated by the maximum target discharge pressure selection unit 30A.
  • the discharge amount required to make the discharge pressure of the pump 12 coincide with the target discharge pressure is calculated and output to the target discharge amount correction unit 30C.
  • the target discharge amount correction unit 30C calculates the target discharge amount by dividing the discharge amount input from the PID control unit 30B by the rotation number of the engine 11 detected by the engine rotation number detection unit 11A.
  • the target discharge amount is output to the tilt amount adjustment unit 12A.
  • Each inflow control unit 19A, 19B is provided between, for example, the hydraulic pump 12, the turning motor 3a, and the boom cylinder 4a, and is a pressure control valve that controls the pressure of hydraulic fluid that passes as shown in FIG. 6 (a).
  • electromagnetic proportional pressure reducing valves 19A1 and 19B1 As electromagnetic proportional pressure reducing valves 19A1 and 19B1.
  • Each of the electromagnetic proportional pressure reducing valves 19A1, 19B1 is driven by receiving a command current for the target turning driving pressure and the target boom driving pressure input from the external limiter processing units 26A2, 26B2, and decreases the opening amount as the command current increases. I am doing so.
  • the electromagnetic proportional pressure reducing valves 19A1 and 19B1 of the inflow control units 19A and 19B are, for example, directions in which the primary side (hydraulic pump 12 side) and the secondary side (swing motor 3a and boom cylinder 4a side) communicate with each other.
  • the electromagnetic proportional pressure reducing valves 19A1 and 19B1 are arranged on the secondary side (swing motor 3a, 19b2) when the magnitude of the command current I to the electromagnetic solenoids 19a2 and 19b2 is less than a predetermined current value IA.
  • the set pressure PS on the boom cylinder 4a side is the maximum value PSmax and the magnitude of the command current I is equal to or greater than the predetermined current value IA
  • the set pressure PS on the secondary side (the swing motor 3a side and the boom cylinder 4a side) is
  • the opening is set so that the set pressure PS on the secondary side (the swing motor 3a side and the boom cylinder 4a side) becomes 0A. The amount is adjusted.
  • the electromagnetic proportional pressure reducing valves 19A1 and 19B1 are arranged on the primary side (hydraulic pump 12 side) and the secondary side by the elastic force of the springs 19a1 and 19b1.
  • the command current I is greater than or equal to a predetermined current value IA while keeping the switching position (the D position shown in FIG. 6A) in which the (turning motor 3a, boom cylinder 4a side) communicates
  • the springs 19a1 and 19b1 The main body moves against the elastic force, and is switched to a switching position (E position shown in FIG. 6A) where the hydraulic oil tank 13 communicates.
  • Each of the electromagnetic proportional pressure reducing valves 19A1 and 19B1 causes the secondary side (swing motor 3a, boom cylinder 4a side) hydraulic oil to act against the elastic force of the springs 19a1 and 19b1, thereby rotating the secondary side (swinging).
  • the hydraulic oil in the motor 3a and boom cylinder 4a side becomes excessive, the hydraulic oil is allowed to flow out to the hydraulic oil tank 13.
  • the tilt amount control unit 12A receives the target discharge amount from the target discharge amount correction unit 30C, and adjusts the tilt amount of the hydraulic pump 12 according to the target discharge amount, thereby adjusting the discharge amount of the hydraulic pump 12 to the target discharge.
  • the target discharge amount corrected by the amount correction unit 30C is controlled.
  • the operator seated on the driving seat in the cab 7 operates the left operating lever 15A to the left or right to make the pilot pressure of the pilot pressure oil discharged from the pilot pump maximum, and this pilot pressure is reduced. Since it acts on the direction control valve 16A on the swing motor 3a side, the switching position of the direction control valve 16A is changed from the neutral position (position B shown in FIG. 2) to the left position (position A shown in FIG. 2) or the right position (FIG. 2). (C position shown), and the opening amount of the direction control valve 16A is maximized.
  • the speed sensor 18 ⁇ / b> A detects the speed of the turning motor 3 a and outputs a detection signal to the controller 20.
  • the discharge pressure sensor 17 detects the discharge pressure of the hydraulic pump 12 and outputs a detection signal to the controller 20.
  • the PID controller 26A1 of the target drive pressure calculator 26A PID control is performed on the speed of the turning motor 3a detected by the sensor 18A and the target turning speed VRmax calculated by the target speed calculation unit 25A1, thereby matching the speed of the turning motor 3a with the target turning speed VRmax.
  • the required turning drive pressure Px is obtained, and the calculation result is output to the limiter processing unit 26A2 of the target drive pressure calculation unit 26A.
  • the limiter processing unit 26A2 compares the swing drive pressure Px calculated by the PID control unit 26A1 with the upper limit pressure PRmax of the swing drive pressure set by the pressure limiting unit 25A2. At this time, as described above, since the upper limit pressure PRmax of the turning drive pressure set by the pressure limiting unit 25A2 is the maximum value, the turning drive pressure Px calculated by the PID control unit 26A1 is set by the pressure limiting unit 25A2.
  • the upper limit pressure PRmax of the turning drive pressure is not more than the upper limit pressure PRmax and is not restricted by the pressure restriction unit 25A2.
  • the limiter processing unit 26A2 obtains the turning drive pressure Px calculated by the PID control unit 26A1 as it is as the target turning drive pressure.
  • the subtracted calculation result is output to the target discharge amount calculation unit 30 of the controller 20.
  • the speed sensor 18B detects the speed of the boom cylinder 4a and outputs a detection signal to the controller 20.
  • the discharge pressure sensor 17 detects the discharge pressure of the hydraulic pump 12 and outputs a detection signal to the controller 20.
  • PB PBmin
  • the unit of boom speed is normally described by m / s etc., it abbreviate
  • the limiter processing unit 26B2 When the limiter processing unit 26B2 inputs the calculation result from the PID control unit 26B1, the limiter processing unit 26B2 compares the boom driving pressure (0 MPa) calculated by the PID control unit 26B1 with the upper limit pressure PBmin of the boom driving pressure set by the pressure limiting unit 25B2. . At this time, as described above, the boom driving pressure calculated by the PID control unit 26B1 is 0 MPa, and the upper limit pressure PBmin of the boom driving pressure set by the pressure limiting unit 25B2 is the minimum value and larger than 0 MPa. 26B2 calculates
  • the limiter processing unit 26B2 outputs the maximum value Imax corresponding to the target boom drive pressure (0 MPa) as the command current I to the inflow control unit 19B, and subtracts the predetermined value 1 MPa from the target boom drive pressure (0 MPa).
  • the calculation result is output to the target discharge amount calculation unit 30. Since the calculation result output at this time is a negative value, 0 MPa is output.
  • the input value ((Px-1) MPa) input from the limiter processing unit 26A2 and The input value (0 MPa) input from the limiter processing unit 26B2 is compared.
  • the input value input from the limiter processing unit 26A2 is a value obtained by subtracting 1 MPa from the turning drive pressure Px calculated by the PID control unit 26A1 ((Px ⁇ 1) MPa), and is 0 MPa or more. Therefore, it is larger than the input value (0 MPa) input from the limiter processing unit 26B2.
  • the maximum target discharge pressure selection unit 30A selects the input value ((Px-1) MPa) input from the limiter processing unit 26A2 and obtains it as the target discharge pressure of the hydraulic pump 12, and the calculation result is the target discharge amount calculation unit. It outputs to 30 PID control part 30B.
  • the PID control unit 30B inputs the calculation result from the maximum target discharge pressure selection unit 30A, the discharge pressure of the hydraulic pump 12 detected by the discharge pressure sensor 17 and the hydraulic pump 12 calculated by the maximum target discharge pressure selection unit 30A.
  • the discharge amount required to make the discharge pressure of the hydraulic pump 12 coincide with the target discharge pressure ((Px-1) MPa)
  • the calculation result is output to the target discharge amount correction unit 30C of the target discharge amount calculation unit 30.
  • the target discharge amount correction unit 30C When the target discharge amount correction unit 30C receives the calculation result from the PID control unit 30B, the target discharge amount correction unit 30C divides the discharge amount calculated by the PID control unit 30B by the rotation number of the engine 11 detected by the engine rotation number detection unit 11A. Thus, the target discharge amount is obtained, and the calculation result is output to the tilt amount adjustment unit 12A.
  • the tilt amount adjustment unit 12A adjusts the tilt amount of the hydraulic pump 12, and the discharge amount of the hydraulic pump 12 is corrected by the target discharge amount correction unit 30C. The target discharge amount is controlled.
  • the electromagnetic proportional pressure reducing valve 19A1 of the inflow control unit 19A receives the command current Ix (0 ⁇ Ix ⁇ Imax) from the limiter processing unit 26A2, the opening amount is adjusted and the set pressure PS on the secondary side (swing motor 3a side) is adjusted. Is controlled to be the pressure Px corresponding to the command current Ix, that is, the turning drive pressure Px calculated by the PID control unit 26A1.
  • the electromagnetic proportional pressure reducing valve 19B1 of the inflow control unit 19B receives the command current Imax from the limiter processing unit 26B2, the opening amount is minimized and the set pressure PS on the secondary side (boom cylinder 4a side) is set to the command current Imax. To a pressure (0 MPa) corresponding to.
  • the discharge pressure of the hydraulic pump 12 becomes a pressure ((Px-1) MPa) obtained by subtracting a predetermined value 1 MPa from the swing drive pressure Px calculated by the PID control unit 26A1, and the discharge amount of the swing motor 3a
  • the flow rate makes the speed coincide with the target turning speed VRmax.
  • the inflow control unit 19A controls the pressure on the secondary side (the swing motor 3a side) to be the swing drive pressure Px calculated by the PID control unit 26A1, and the swing motor 3a via the direction control valve 16A.
  • the pressure ((Px-1) MPa) on the primary side (hydraulic pump 12 side) of the inflow control unit 19A is smaller than the set pressure Px on the secondary side (swing motor 3a side) by a predetermined value 1 MPa
  • the pressure generated on the secondary side of the electromagnetic proportional pressure reducing valve 19A1 of the inflow control unit 19A shown in FIG. 6A is smaller than the set pressure Px by a predetermined value 1 MPa.
  • the secondary pressure fed back to the electromagnetic proportional pressure reducing valve 19A1 (the broken line portion in FIG. 6A) is also smaller than the set pressure Px by a predetermined value 1 MPa, so that the spring switching position is that of the electromagnetic proportional pressure reducing valve 19A1.
  • the electromagnetic proportional pressure reducing valve 19B1 controls the set pressure PS on the secondary side (boom cylinder 4a side) to a pressure (0 MPa) corresponding to the command current Imax, that is, the switching position is shifted to the E position. Even if hydraulic fluid is discharged from the boom cylinder 4a to the boom cylinder 4a, the hydraulic fluid is blocked by the electromagnetic proportional pressure reducing valve 19B1. Furthermore, since the directional control valve 19B maintains the neutral position (the B position shown in FIG. 2), the discharge pressure of the hydraulic pump 12 does not act on the boom cylinder 4a, and the boom 4A maintains the stopped state.
  • the operator seated on the driving seat in the cab 7 operates the left operating lever 15A to the left or right by a half lever, so that the pilot pressure oil discharged from the pilot pump according to the operating amount of the left operating lever 15A is obtained. Is depressurized. Since the pilot pressure of this pilot pressure oil acts on the direction control valve 16A on the swing motor 3a side, the switching position of the direction control valve 16A is changed from the neutral position (position B shown in FIG. 2) to the left position (shown in FIG. 2). (A position) or right position (C position shown in FIG. 2), the direction control valve 16A opens according to the operation amount of the left operation lever 15A.
  • the speed sensor 18 ⁇ / b> A detects the speed of the turning motor 3 a and outputs a detection signal to the controller 20.
  • the discharge pressure sensor 17 detects the discharge pressure of the hydraulic pump 12 and outputs a detection signal to the controller 20.
  • the pressure limiting unit 25A2 of the controller 20 applies the operation amount X1 detected by the operation amount sensor 15A1 to the functional relationship of the upper limit pressure table 25a2, thereby setting the upper limit pressure PR of the turning drive pressure to the minimum value PRmin.
  • the PID controller 26A1 of the target drive pressure calculator 26A PID control is performed on the speed of the turning motor 3a detected by the sensor 18A and the target turning speed V1 (0 ⁇ V1 ⁇ VRmax) calculated by the target speed calculation unit 25A1, thereby eliminating the speed deviation, that is, turning A turning drive pressure Py required to make the speed of the motor 3a coincide with the target turning speed V1 (0 ⁇ V1 ⁇ VRmax) is obtained.
  • the set pressure of the relief valve 21 is set to PrL larger than the above-described pressure P1 (PRmin ⁇ P1 ⁇ PRmax) in the upper limit pressure table 25a2 (P1 ⁇ PrL).
  • the set pressure PrL is set as the upper limit value of the PID control unit 26A1
  • the PID control unit 26A1 since the PID control unit 26A1 has a large inertia load, the speed deviation between the target speed obtained by the target speed calculation unit 25A1 and the speed detected by the speed sensor 18 Since it takes time to eliminate the rotation, the turning drive pressure Py reaches PrL, and this calculation result is used as the limiter processing unit 2 of the target drive pressure calculation unit 26A. And outputs it to the A2.
  • the target drive pressure of each actuator does not exceed the relief setting pressure PrL by setting the maximum value PRmax of the upper limit pressure to a value equal to or less than the relief setting pressure PrL, and thus exceeds the normal relief setting pressure PrL.
  • the flow rate discharged from the relief valve 21 to the hydraulic oil tank 13 can be suppressed, and an energy saving effect can be obtained.
  • the limiter processing unit 26A2 compares the swing drive pressure PrL calculated by the PID control unit 26A1 with the upper limit pressure P1 of the swing drive pressure set by the pressure limiting unit 25A2. At this time, as described above, the turning drive pressure PrL calculated by the PID control unit 26A1 is larger than the upper limit pressure P1 of the turning drive pressure set by the pressure limiting unit 25A2 (P1 ⁇ PrL), so the PID control unit 26A1. The calculated turning drive pressure PrL is limited by the pressure limiting unit 25A2.
  • the input value ((P1-1) MPa) input from the limiter processing unit 26A2 and The input value (0 MPa) input from the limiter processing unit 26B2 is compared.
  • the input value ((P1-1) MPa) input from the limiter processing unit 26A2 is a value obtained by subtracting the predetermined value 1 MPa from the upper limit pressure P1 of the turning drive pressure set by the pressure limiting unit 25A2. Since it is 0 MPa or more, it is larger than the input value (0 MPa) input from the limiter processing unit 26B2.
  • the maximum target discharge pressure selection unit 30A selects the input value ((P1-1) MPa) input from the limiter processing unit 26A2 and obtains it as the target discharge pressure of the hydraulic pump 12, and calculates the calculation result as a target discharge amount calculation. To the PID control unit 30B of the unit 30.
  • the PID control unit 30B inputs the calculation result from the maximum target discharge pressure selection unit 30A, the discharge pressure of the hydraulic pump 12 detected by the discharge pressure sensor 17 and the hydraulic pump 12 calculated by the maximum target discharge pressure selection unit 30A.
  • the discharge amount required to make the discharge pressure of the hydraulic pump 12 coincide with the target discharge pressure ((P1-1) MPa)
  • the calculation result is output to the target discharge amount correction unit 30C of the target discharge amount calculation unit 30.
  • the target discharge amount correction unit 30C When the target discharge amount correction unit 30C receives the calculation result from the PID control unit 30B, the target discharge amount correction unit 30C divides the discharge amount calculated by the PID control unit 30B by the rotation number of the engine 11 detected by the engine rotation number detection unit 11A. Thus, the target discharge amount is obtained, and the calculation result is output to the tilt amount adjustment unit 12A.
  • the tilt amount adjustment unit 12A adjusts the tilt amount of the hydraulic pump 12, and the discharge amount of the hydraulic pump 12 is corrected by the target discharge amount correction unit 30C. The target discharge amount is controlled.
  • the electromagnetic proportional pressure reducing valve 19A1 of the inflow control unit 19A receives the command current I1 from the limiter processing unit 26A2, the opening amount is adjusted and the set pressure PS on the secondary side (swing motor 3a side) is set to the command current I1. Is controlled so as to be the upper limit pressure P1 of the turning drive pressure set by the pressure limiting unit 25A2.
  • the electromagnetic proportional pressure reducing valve 19B1 of the inflow control unit 19B receives the command current Imax from the limiter processing unit 26B2, the opening amount is minimized and the set pressure PS on the secondary side (boom cylinder 4a side) is set to the command current Imax. To a pressure (0 MPa) corresponding to.
  • the discharge pressure of the hydraulic pump 12 becomes a pressure ((P1-1) MPa) obtained by subtracting the predetermined value 1 MPa from the upper limit pressure P1 of the turning drive pressure set by the pressure limiting unit 25A2, and the discharge amount is set to the discharge pressure.
  • the flow rate is determined by the pressure ((P1-1) MPa).
  • the inflow control unit 19A controls the pressure on the secondary side (swing motor 3a side) to be the upper limit pressure P1 of the swing drive pressure set by the pressure limiting unit 25A2, and via the direction control valve 16A. It can be made to act on the turning motor 3a.
  • the turning drive pressure Py calculated by the PID control unit 26A1 is large, the pressure exceeding the upper limit pressure P1 of the turning drive pressure set by the pressure limiting unit 25A2 is swung by being limited by the pressure limiting unit 25A2. Since it does not act on the motor 3a, the driving force of the turning motor 3a can be suppressed and the turning body 3 can be turned. Thereby, high force controllability of the swing body 3 is obtained with respect to the operation input of the left operation lever 15A while ensuring speed controllability within the range of the upper limit pressure P1 of the swing drive pressure set by the pressure limiting unit 25A2. be able to. Therefore, the operator can obtain an operation feeling when the driving force of the turning motor 3a is controlled, and can perform work while grasping the load applied to the turning operation of the turning body 3 with the operation feeling of the left operation lever 15A. Can do.
  • the turning drive pressure Py calculated by the PID control unit 26A1 becomes equal to or lower than the upper limit pressure P1 of the turning drive pressure set by the pressure restriction unit 25A2, the pressure restriction unit 25A2 Since the restriction is not applied, the turning drive pressure Py calculated by the PID control unit 26A1 can be applied to the turning motor 3a similarly to the operation when the full lever operation of the left operation lever 15A is performed.
  • the speed controllability of the body 3 can be further improved.
  • the pressure ((P1-1) MPa) on the primary side (hydraulic pump 12 side) of the inflow control unit 19A is smaller than the set pressure P1 on the secondary side (swing motor 3a side) by a predetermined value 1 MPa.
  • the pressure loss between the primary side and the secondary side of the electromagnetic proportional pressure reducing valve 19A1 can be suppressed to a necessary minimum. Thereby, even when the half lever operation of the left operation lever 15A is performed, the pressure loss generated in the inflow control unit 19A can be reduced, so that the energy efficiency in the hydraulic circuit can be increased.
  • the electromagnetic proportional pressure reducing valve 19B1 is closed to control the set pressure PS on the secondary side (boom cylinder 4a side) to a pressure (0 MPa) corresponding to the command current Imax, that is, the switching position is shifted to the E position. Even if the hydraulic oil is discharged from the pump 12 to the boom cylinder 4a, the hydraulic oil is blocked by the electromagnetic proportional pressure reducing valve 19B1. Furthermore, since the directional control valve 19B maintains the neutral position (the B position shown in FIG. 2), the discharge pressure of the hydraulic pump 12 does not act on the boom cylinder 4a, and the boom 4A maintains the stopped state.
  • control operation of the controller 20 when the half lever operation of the left operation lever 15A is performed and the half lever operation of the right operation lever 15B is performed in the combined operation will be described.
  • control operations of the target speed calculation unit 25A1, the pressure limiting unit 25A2, and the target drive pressure calculation unit 26A in the controller 20 are the same as when the above-described half lever operation of the left operation lever 15A is performed, and overlapping descriptions are given. Is omitted.
  • the operator seated on the driving seat in the cab 7 operates the right operation lever 15B halfway forward or rearward, thereby pilot pressure oil discharged from the pilot pump according to the operation amount of the right operation lever 15B. Is depressurized. Since the pilot pressure of the pilot pressure oil acts on the direction control valve 16B on the boom cylinder 4a side, the switching position of the direction control valve 16B is changed from the neutral position (position B shown in FIG. 2) to the left position (shown in FIG. 2). The position control valve 16B is opened according to the amount of operation of the right operation lever 15B by switching to the A position) or the right position (C position shown in FIG. 2).
  • the speed sensor 18 ⁇ / b> A detects the speed of the boom cylinder 4 a and outputs a detection signal to the controller 20.
  • the discharge pressure sensor 17 detects the discharge pressure of the hydraulic pump 12 and outputs a detection signal to the controller 20.
  • the target speed calculation unit 25B1 of the controller 20 performs the operation amount X2 (0 ⁇ X2 ⁇ ) detected by the operation amount sensor 15B1 with respect to the functional relationship of the target speed table 25b1.
  • the pressure limiting unit 25B2 of the controller 20 applies the operation amount X2 detected by the operation amount sensor 15B1 to the functional relationship of the upper limit pressure table 25b2, thereby setting the upper limit pressure PB of the boom drive pressure to the minimum value PBmin.
  • the target drive pressure calculation unit 26B receives the detection signal from the speed sensor 18B, the calculation result from the target speed calculation unit 25B1, and the setting result from the pressure limiting unit 25B2, the PID control unit 26B1 of the target drive pressure calculation unit 26B By performing PID control on the speed of the boom cylinder 4a detected by the sensor 18B and the target boom speed V2 calculated by the target speed calculation unit 25B1, the speed deviation is eliminated, that is, the speed of the boom cylinder 4a is set to the target boom. A boom driving pressure Pz required to match the speed V2 is obtained.
  • the inertia load with respect to the turning operation of the boom 4A is relatively large, and the pressure in the hydraulic circuit is limited by the relief valve 21 or the like.
  • the set pressure of the relief valve 21 is set to PrL (P2 ⁇ PrL) in the same manner as the above-described PID control unit 26A1 that is larger than the pressure P2 in the upper limit pressure table 25b2, the boom calculated by the PID control unit 26B1 is used.
  • the driving pressure is PrL as described above.
  • the PID control unit 26B1 obtains PrL as the boom drive pressure Pz and outputs the calculation result to the limiter processing unit 26B2 of the target drive pressure calculation unit 26B.
  • the limiter processing unit 26B2 compares the boom driving pressure PrL calculated by the PID control unit 26B1 with the upper limit pressure P2 of the boom driving pressure set by the pressure limiting unit 25B2. At this time, as described above, the boom drive pressure PrL calculated by the PID control unit 26B1 is larger than the upper limit pressure P2 of the boom drive pressure set by the pressure limiting unit 25B2 (P2 ⁇ PrL), so the PID control unit 26B1. The calculated boom drive pressure PrL is limited by the pressure limiting unit 25B2.
  • the maximum target discharge pressure selection unit 30A of the target discharge amount calculation unit 30 inputs the calculation results from the limiter processing units 26A2 and 26B2, the input value ((P1-1) MPa) input from the limiter processing unit 26A2 and The input value ((P2-1) MPa) input from the limiter processing unit 26B2 is compared.
  • the maximum target discharge pressure selection unit 30A selects the input value ((P1-1) MPa) input from the limiter processing unit 26A2 and obtains it as the target discharge pressure of the hydraulic pump 12, and calculates the calculation result as a target discharge amount calculation. To the PID control unit 30B of the unit 30.
  • the PID control unit 30B inputs the calculation result from the maximum target discharge pressure selection unit 30A, the discharge pressure of the hydraulic pump 12 detected by the discharge pressure sensor 17 and the hydraulic pump 12 calculated by the maximum target discharge pressure selection unit 30A.
  • the calculation result is output to the target discharge amount correction unit 30C of the target discharge amount calculation unit 30.
  • the target discharge amount correction unit 30C When the target discharge amount correction unit 30C receives the calculation result from the PID control unit 30B, the target discharge amount correction unit 30C divides the discharge amount calculated by the PID control unit 30B by the rotation number of the engine 11 detected by the engine rotation number detection unit 11A. Thus, the target discharge amount is obtained, and the calculation result is output to the tilt amount adjustment unit 12A.
  • the tilt amount adjustment unit 12A adjusts the tilt amount of the hydraulic pump 12, and the discharge amount of the hydraulic pump 12 is corrected by the target discharge amount correction unit 30C. The target discharge amount is controlled.
  • the electromagnetic proportional pressure reducing valve 19A1 of the inflow control unit 19A receives the command current I1 from the limiter processing unit 26A2, the opening amount is adjusted and the set pressure PS on the secondary side (swing motor 3a side) is set to the command current I1. Is controlled so as to be the upper limit pressure P1 of the turning drive pressure set by the pressure limiting unit 25A2.
  • the electromagnetic proportional pressure reducing valve 19B1 of the inflow control unit 19B receives the command current I2 from the limiter processing unit 26B2, the opening amount is adjusted and the set pressure PS on the secondary side (the boom cylinder 4a side) is set to the command current I2. Is controlled so as to become the upper limit pressure P2 of the boom driving pressure set by the pressure limiting unit 25B2.
  • the discharge pressure of the hydraulic pump 12 becomes a pressure ((P1-1) MPa) obtained by subtracting a predetermined value 1 MPa from the upper limit pressure P1 of the swing drive pressure set by the pressure limiter 25A2, and the discharge amount is the swing speed.
  • the flow rate is determined by the discharge pressure ((P1-1) MPa) with respect to the motor 3a and the boom cylinder 4a. Accordingly, it is possible to obtain the same operation and effect as the above-described half lever operation of the left operation lever 15A.
  • the electromagnetic proportional pressure reducing valve 19B1 controls the set pressure PS on the secondary side (boom cylinder 4a side) to the upper limit pressure P2 ( ⁇ P1) of the turning drive pressure set by the pressure limiting unit 25B2,
  • the pressure ((P1-1) MPa) on the primary side (hydraulic pump 12 side) of the control unit 19A becomes larger than the set pressure P2 on the secondary side (boom cylinder 4a side), and the operation discharged from the hydraulic pump 12
  • the oil is adjusted to a flow rate corresponding to the set pressure P2 by the electromagnetic proportional pressure reducing valve 19B1.
  • the upper limit pressure P2 of the boom drive pressure set by the pressure limiting unit 25B2 can be applied to the boom cylinder 4a via the direction control valve 16B.
  • the boom 4A can be rotated while suppressing the driving force of the boom cylinder 4a.
  • high force controllability of the boom 4A can be obtained with respect to the operation input of the right operation lever 15B, while ensuring speed controllability within the range of the boom drive pressure upper limit pressure P2 set by the pressure limiter 25B2.
  • Can do Therefore, the operator can obtain an operation feeling when the driving force of the boom cylinder 4a is controlled, and can perform an operation while grasping the load applied to the rotation operation of the boom 4A with the operation feeling of the right operation lever 15B. Can do.
  • the pressure limiting unit 25B2 Since there is no restriction, the boom drive pressure Pz calculated by the PID control unit 26B1 can be applied to the boom cylinder 4a in the same manner as the operation when the full lever operation of the left operation lever 15A is performed. The speed controllability of 4A can be further improved.
  • the force controllability can be sufficiently improved while ensuring the above. Thereby, stable operation of the swing motor 3a and the boom cylinder 4a can be realized, and a smooth operation feeling can be obtained. Therefore, the operation performance of the operation levers 15A and 15B can be improved, and the working efficiency of the hydraulic excavator 1 can be improved. Can do.
  • the closer the operation of the operation levers 15A and 15B is to the full lever operation the more excellent acceleration performance can be exerted on the swing body 3 and the boom 4A by the speed controllability obtained.
  • the speed intended by the operator can be easily obtained.
  • the electromagnetic proportional pressure reducing valves 19A1 and 19B1 are used as the pressure control valves of the inflow control units 19A and 19B, the flow rate of the hydraulic oil flowing into the swing motor 3a and the boom cylinder 4a is controlled. Since the control can be easily executed by the electromagnetic proportional pressure reducing valves 19A1 and 19B1, the hydraulic circuit is not complicated, and the hydraulic circuit can be efficiently manufactured. Thereby, the burden of the operator in the manufacturing process of a hydraulic circuit can be reduced, and manufacturing efficiency can be improved.
  • the electromagnetic proportional pressure reducing valves 19A1 and 19B1 control the secondary side (swing motor 3a side, boom cylinder 4a side) set pressure PS in accordance with the input command current I, thereby controlling the secondary side (swinging). Since the pressure on the motor 3a side and the boom cylinder 4a side) is adjusted to be equal to or lower than the set pressure PS, the hydraulic oil can be accurately guided from the hydraulic pump 12 to the swing motor 3a and the boom cylinder 4a.
  • the electromagnetic proportional pressure reducing valves 19A1 and 19B1 are arranged on the secondary side (the swing motor 3a side and the boom cylinder 4a side) when the magnitude of the command current I is equal to or greater than a predetermined current value IA.
  • the electromagnetic proportional pressure reducing valves 19A1 and 19B1 are open, so that the operator operates the operation levers 15A and 15B.
  • the driving pressure of the swing motor 3a and the boom cylinder 4a can be ensured, and the swing motor 3a and the boom cylinder 4a can be operated reliably, and the high reliability of the hydraulic excavator 1 can be ensured.
  • the discharge pressure of the hydraulic pump 12 is lowered by a predetermined value, so that the one with the highest load on the inflow control units 19A and 19B can supply the hydraulic oil to the actuator at the maximum opening. Therefore, the pressure loss can be minimized and energy saving can be achieved.
  • the target discharge amount correction unit 30C of the target discharge amount calculation unit 30 divides and corrects the discharge amount input from the PID control unit 30B by the engine speed detected by the engine speed detection unit 11A. Thus, even if the rotational speed of the engine 11 fluctuates greatly, the influence can be suppressed, so that the discharge amount of the hydraulic pump 12 can be controlled stably.
  • FIG. 7 is a diagram showing a configuration of a controller provided in the second embodiment of the present invention
  • FIG. 8 is a function of a target speed table related to the turning motor corrected by the relation correcting unit provided in the second embodiment of the present invention
  • FIG. 9 is a diagram for explaining the relationship
  • FIG. 9 is a diagram for explaining the functional relationship of the target speed table related to the boom cylinder corrected by the relationship correction unit provided in the second embodiment of the present invention.
  • the functional relationship of the target speed table 25a1 is determined by the target drive pressure calculator 26A.
  • a relationship correction unit 35A that corrects the calculated target turning drive pressure according to the target boom drive pressure;
  • a relationship correction unit 35B that corrects the functional relationship of the target speed table 25b1 according to the target boom drive pressure calculated by the target drive pressure calculation unit 26B; It has.
  • the basic configuration of the second embodiment of the present invention is the same as that of the first embodiment, and the same or corresponding parts as those of the first embodiment are denoted by the same reference numerals, and redundant description is omitted.
  • the relationship correction unit 35A inputs the target turning drive pressure calculated by the target drive pressure calculation unit 26A, for example, and the larger the target turning drive pressure, the more the target In the functional relationship of the speed table 25a1, correction is performed to reduce the absolute value of the gradient of the target turning speed VR with respect to the operation amount XL. Then, the target speed calculation unit 25A1 calculates the target turning speed VR by applying the operation amount XL detected by the operation amount sensor 15A1 to the functional relationship of the target speed table 25a1 corrected by the relationship correction unit 35A. I have to.
  • the relationship correction unit 35B inputs, for example, the target boom drive pressure calculated by the target drive pressure calculation unit 26B, and the target speed table 25b1 increases as the target boom drive pressure increases. In such a functional relationship, correction is performed to reduce the absolute value of the inclination of the target boom speed VB with respect to the operation amount XR. Then, the target speed calculation unit 25B1 calculates the target boom speed VB by applying the operation amount XR detected by the operation amount sensor 15B1 to the functional relationship of the target speed table 25b1 corrected by the relationship correction unit 35B. I have to.
  • the relationship correction unit 35A determines the functional relationship of the target speed table 25a1 as the target drive pressure calculation unit.
  • the correction is made according to the target turning speed calculated by 26A
  • the relationship correction unit 35B corrects the functional relationship of the target speed table 25b1 according to the target boom speed calculated by the target drive pressure calculation unit 26B, thereby speed control.
  • force controllability can be adjusted easily. For example, speed control, such as excavation of heavy rocks, or swivel lateral movement operation that presses the side surface of the bucket 4C against the groove side surface using swiveling in order to solidify so that the sediment on the groove side surface does not collapse during groove excavation.
  • the discharge amount of the hydraulic pump 12 can be suppressed, the invalid flow rate discharged from the relief valve 21 is suppressed, Energy saving can be improved.
  • FIG. 10 is a diagram for explaining an inflow control unit provided in the third embodiment of the present invention.
  • FIG. 10A is a diagram showing a configuration of an electromagnetic proportional throttle valve constituting the inflow control unit, and FIG. The figure which shows the characteristic of an electromagnetic proportional throttle valve,
  • FIG. 11 is a figure which shows the structure of the controller with which 3rd Embodiment of this invention was equipped.
  • the third embodiment of the present invention differs from the first embodiment described above in the first embodiment in that each inflow control unit 19A, 19B determines the pressure of hydraulic fluid that passes through as shown in FIG. 6 (a). While the electromagnetic proportional pressure reducing valves 19A1 and 19B1 are included as pressure control valves to be controlled, in the third embodiment, instead of the electromagnetic proportional pressure reducing valves 19A1 and 19B1, for example, as shown in FIG. It is that electromagnetic proportional throttle valves 19A2 and 19B2 are included as control valves.
  • the basic configuration of the third embodiment of the present invention is the same as that of the first embodiment, and the same or corresponding parts as those of the first embodiment are denoted by the same reference numerals, and redundant description is omitted.
  • each of the electromagnetic proportional throttle valves 19A2 and 19B2 includes, for example, a primary side (hydraulic pump 12 side) and a secondary side (swing motor 3a side, boom cylinder 4a) as in the first embodiment.
  • each of the electromagnetic proportional throttle valves 19A2 and 19B2 has an opening area A that is a maximum value Amax when the magnitude of the command current I is less than a predetermined current value IB, and the magnitude of the command current I.
  • the opening area A is inversely proportional to the magnitude of the command current I, and when the magnitude of the command current I is the maximum value Imax, the opening amount is set so that the opening area A becomes 0A. Is adjusted to control the pressure on the secondary side (swing motor 3a side, boom cylinder 4a side).
  • each of the electromagnetic proportional throttle valves 19A2 and 19B2 has a primary side (hydraulic pump 12 side) and a secondary side (side of the hydraulic pump 12) by the elastic force of the springs 19a1 and 19b1.
  • a predetermined current value IB when the swing motor 3a side and the boom cylinder 4a side) are kept in the switching position (the F position shown in FIG. 10A)
  • the springs 19a1 and 19b1 Switching position G position shown in FIG. 10 (a) in which the main body moves against the elastic force and the primary side (hydraulic pump 12 side) and the secondary side (swing motor 3a side, boom cylinder 4a side) are cut off. ).
  • the controller 20 is calculated by the target discharge pressure and target drive pressure calculator 26A calculated by the maximum target discharge pressure selector 30A of the target discharge amount calculator 30 as shown in FIG.
  • the differential pressure calculation unit 27A that calculates the differential pressure with the target turning drive pressure, the target discharge pressure calculated by the maximum target discharge pressure selection unit 30A, and the target boom drive pressure calculated by the target drive pressure calculation unit 26B And a differential pressure calculation unit 27B that calculates the difference.
  • the controller 20 calculates an opening area A of the electromagnetic proportional throttle valve 19A2 based on the differential pressure calculated by the differential pressure calculator 27A and the target turning speed calculated by the target speed calculator 25A1.
  • the flow rate through each of the electromagnetic proportional throttle valves 19A2 and 19B2 is Q
  • the opening area is A
  • the primary side hydroaulic pump 12 side
  • the secondary side tilt motor 3a side, boom cylinder 4a side
  • the differential pressure is ⁇ P
  • the hydraulic fluid density is ⁇
  • the flow coefficient is C
  • the flow rate Q is the product of the target turning speed calculated by the target speed calculating unit 25A1 and the motor capacity that is the specification of the turning motor 3a, and the primary side (hydraulic pump 12 side) and the secondary side (turning motor 3a).
  • the effective differential pressure ⁇ P is calculated from the differential pressure calculated by the differential pressure calculation unit 27A, and the density ⁇ and the flow coefficient C of the hydraulic oil are respectively predetermined constants. Therefore, the opening area calculation unit 28A Calculates the opening area A of the electromagnetic proportional throttle valve 19A2 using the differential pressure calculated by the differential pressure calculation unit 27A, the target turning speed calculated by the target speed calculation unit 25A1, and the above equation (2). I have to.
  • the flow rate Q is the product of the target boom speed calculated by the target speed calculator 25B1 and the pressure receiving area of the boom cylinder 4a, and the primary side (hydraulic pump 12 side) and secondary side (boom cylinder 4a side).
  • the effective differential pressure ⁇ P is obtained from the differential pressure calculated by the differential pressure calculation unit 27B, and the hydraulic fluid density ⁇ and the flow coefficient C are respectively predetermined constants.
  • the opening area A of the electromagnetic proportional throttle valve 19B2 is calculated using the differential pressure calculated by the differential pressure calculation unit 27B, the target boom speed calculated by the target speed calculation unit 25B1, and the above equation (2). Yes.
  • the effective differential pressure ⁇ P becomes a negative value by a predetermined value of 1 MPa.
  • the opening area calculation units 28A and 28B use an electromagnetic proportional throttle. An operation is performed on the valves 19A2 and 19B2 so as to shift the switching position to the F position.
  • the same operational effects as those of the first embodiment described above can be obtained, and electromagnetic proportional throttle valves 19A2 and 19B2 can be used as pressure control valves of the inflow control units 19A and 19B. Since the hydraulic circuit can be miniaturized, the manufacturing cost can be reduced. Thereby, high productivity can be realized.
  • the hydraulic excavator 1 includes the hydraulic pump 12 and the four hydraulic actuators of the swing motor 3a, the boom cylinder 4a, the arm cylinder 4b, and the bucket cylinder 4a.
  • the present invention is not limited to this case.
  • the hydraulic actuator includes other than the swing motor 3a, the boom cylinder 4a, the arm cylinder 4b, and the bucket cylinder 4a. But it ’s okay.
  • the target drive pressure calculation unit 26A outputs a value lower than the calculated target turning drive pressure by a predetermined value 1 MPa to the target discharge amount calculation unit 30 as a calculation result
  • the target drive The case where the pressure calculation unit 26B outputs a value lower than the calculated target boom drive pressure by the predetermined value 1 MPa as the calculation result to the target discharge amount calculation unit 30 has been described. Is preferably close to 0 MPa from the viewpoint of the accuracy of control of the hydraulic actuators 3a and 4a. However, in consideration of control variations caused by the accuracy of the pressure control of the hydraulic pump 12 and the control of the inflow control units 19A and 19B, etc. May be set.
  • the target drive pressure may be output to the target discharge amount calculation unit 30 as it is without providing a predetermined value.
  • the driving pressure is the same value.
  • each functional relationship between the target speed table 25a1 of the target speed calculation unit 25A1 and the upper limit pressure table 25a2 of the pressure limiting unit 25A2 is the performance required for the swing operation of the swing body 3.
  • the functional relationship between the target speed table 25b1 of the target speed calculation unit 25B1 and the upper limit pressure table 25b2 of the pressure limiting unit 25B2 takes into consideration the performance required for the pivoting operation of the boom 4A.
  • the functional relationship between the target speed table 25a1 and the upper limit pressure table 25a2 is set in consideration of the balance between the turning operation of the swing body 3 and the other operation parts 4A to 4C.
  • the target speed table 25b1 and the upper limit pressure table Each functional relationship of 25b2 may be set in consideration of the operation balance between the rotation operation of the boom 4A and the other operation parts 3a, 4B, 4C.
  • the cab 7 of the excavator 1 has a work mode setting unit for setting work modes such as a power mode for performing heavy load work and an economy mode for performing light load work, and includes target speed tables 25a1 and 25b1 and upper limit pressure tables.
  • a plurality of functional relationships 25a2 and 25b2 may be set according to the work mode, and may be switched in conjunction with the work mode set by the work mode setting unit.
  • the target speed calculation unit 25A1 is configured such that, for example, as the target turning drive pressure calculated by the target drive pressure calculation unit 26A increases, the target speed with respect to the operation amount XL in the functional relationship of the target speed table 25a1.
  • the target speed calculation unit 25B1 performs correction in the functional relationship of the target speed table 25b1 as the target boom driving pressure calculated by the target driving pressure calculation unit 26B increases.
  • the present invention sets a decrease amount that decreases the absolute value of the inclination of the target turning speed VR with respect to the operation amount XL in the functional relationship of the target speed table 25a1, and sets the target boom with respect to the operation amount XR in the functional relationship of the target speed table 25b1.
  • the operator can freely change the degree of correction of each function relationship of the target speed tables 25a1 and 25b1 by the reduction amount setting unit, so that the operator's operation feeling with respect to the operation levers 15A and 15B can be adjusted, and the operation performance can be improved. It can be improved further.
  • the present invention may include a switching unit that enables or disables correction of each function relationship of the target speed tables 25a1 and 25b1 by the relationship correction unit of the target speed calculation units 25A1 and 25B1. Thereby, the operator can invalidate each function relationship of the target speed tables 25a1 and 25b1 by this switching unit and fix the setting, so that high convenience can be ensured.
  • the electromagnetic proportional pressure reducing valves 19A1 and 19B1 are configured to have a characteristic in which the set pressure PS is inversely proportional to the command current I.
  • the present invention is not limited to this.
  • a valve structure in which the D position and the E position of the electromagnetic proportional pressure reducing valves 19A1 and 19B1 shown in FIG. 6A are exchanged is used, and as the command current I increases, the opening amount increases and the set pressure PS increases. It is good also as a structure.

Abstract

Provided is a hydraulic control device for a work machine with which power controllability can be adequately improved while ensuring the speed controllability of a hydraulic actuator with respect to an operation input from an operation device. The present invention is equipped with: target drive pressure calculation units (26A, 26B), which calculate target values for the drive pressure of hydraulic actuators (3a, 4a) on the basis of the speed detected by speed detection units (18A, 18B) and target values calculated by target speed calculation units (25A1, 25B1); and a target discharge amount calculation unit (30), which calculates a target value for the discharge amount of a hydraulic pump (12) in accordance with the discharge pressure detected by a discharge pressure sensor (17) and the target values calculated by the target drive pressure calculation units (26A, 26B). Inflow control units (19A, 19B) control the pressure of operating oil supplied to the hydraulic actuators (3a, 4a) in accordance with the target values calculated by the target drive pressure calculation units (26A, 26B), and a controller (20) controls the discharge amount of the hydraulic pump (12) so as to achieve the target value calculated by the target discharge amount calculation unit (30).

Description

作業機械の油圧制御装置Hydraulic control device for work machine
　本発明は、油圧ショベル等の作業機械に設けられ、油圧ポンプから複数の油圧アクチュエータへ作動油を吐出して作業機械を駆動するのに好適な作業機械の油圧制御装置に関する。 The present invention relates to a hydraulic control device for a work machine that is provided in a work machine such as a hydraulic excavator and is suitable for driving the work machine by discharging hydraulic oil from a hydraulic pump to a plurality of hydraulic actuators.
　一般に、油圧ショベルやホイールローダ等の作業機械は、油圧ポンプから圧油として吐出された作動油によって動作する油圧シリンダ等の複数の油圧アクチュエータと、これらの油圧アクチュエータを操作する操作装置とを備えており、この操作装置の操作入力に応じて各油圧アクチュエータに作動油が分配されることにより、旋回体の旋回動作やブーム等の回動動作が複合的に行われる。 In general, a work machine such as a hydraulic excavator or a wheel loader includes a plurality of hydraulic actuators such as hydraulic cylinders that are operated by hydraulic oil discharged as pressure oil from a hydraulic pump, and an operation device that operates these hydraulic actuators. The hydraulic oil is distributed to the hydraulic actuators according to the operation input of the operating device, so that the turning operation of the turning body and the turning operation of the boom and the like are performed in a composite manner.
　作業機械の各油圧アクチュエータは動作中にかかる負荷の変動が大きくなり易いので、負荷が変動しても操作装置の操作性能をある程度維持できる油圧制御装置を備えた作業機械が要望されている。このような油圧制御装置に適した技術として、各油圧アクチュエータの負荷を検出して補正を行うロードセンシングシステムが着目されており、この種のロードセンシングシステムが適用された作業機械の従来技術の１つとして超小旋回式油圧作業機が知られている（例えば、特許文献１参照）。 Since each hydraulic actuator of a work machine tends to have a large load fluctuation during operation, there is a demand for a work machine equipped with a hydraulic control device that can maintain the operation performance of the operation device to some extent even if the load fluctuates. As a technique suitable for such a hydraulic control device, a load sensing system that detects and corrects the load of each hydraulic actuator has attracted attention, and is one of the prior arts of work machines to which this type of load sensing system is applied. As an example, an ultra-small turning hydraulic working machine is known (for example, see Patent Document 1).
　具体的には、この従来技術の超小旋回式油圧作業機は、油圧ポンプ、及び旋回モータやブームシリンダ等の複数の油圧アクチュエータの他に、油圧ポンプから各油圧アクチュエータへ吐出された作動油の流れを制御する方向制御弁と、油圧ポンプから各油圧アクチュエータへ吐出された作動油の圧力を制御する圧力補償弁と、油圧ポンプの吐出圧と各油圧アクチュエータの負荷圧とを所定の差圧に保つポンプ容量制御シリンダ及びロードセンシングバルブ等の吐出量制御部とを備えている。 Specifically, this ultra-small swivel hydraulic working machine of the prior art includes a hydraulic pump and a plurality of hydraulic actuators such as a swing motor and a boom cylinder, as well as hydraulic fluid discharged from the hydraulic pump to each hydraulic actuator. A directional control valve for controlling the flow, a pressure compensation valve for controlling the pressure of hydraulic oil discharged from the hydraulic pump to each hydraulic actuator, and the discharge pressure of the hydraulic pump and the load pressure of each hydraulic actuator are set to a predetermined differential pressure. A pump capacity control cylinder to be maintained and a discharge amount control unit such as a load sensing valve are provided.
　そして、圧力補償弁が方向制御弁の前後の差圧を一定に保ち、吐出量制御部が複数の油圧アクチュエータのうち最も高い油圧アクチュエータの負荷圧よりも目標差圧、すなわちロードセンシング差圧だけ高くなるように油圧ポンプの吐出量を制御することにより、各油圧アクチュエータの負荷に拘わらず、方向制御弁のスプールの開口面積に応じて各油圧アクチュエータへ流入する作動油の流量を確保することができる。これにより、操作装置の操作入力に対して各油圧アクチュエータの高い速度制御性を実現することができるので、作業者が所望する各油圧アクチュエータの速度を迅速に得ることができる。 The pressure compensation valve keeps the differential pressure before and after the directional control valve constant, and the discharge amount control unit is higher than the load pressure of the highest hydraulic actuator among the multiple hydraulic actuators by the target differential pressure, that is, the load sensing differential pressure. By controlling the discharge amount of the hydraulic pump in such a manner, it is possible to ensure the flow rate of the hydraulic oil flowing into each hydraulic actuator according to the opening area of the spool of the direction control valve regardless of the load of each hydraulic actuator. . Thereby, since high speed controllability of each hydraulic actuator can be realized with respect to the operation input of the operating device, the speed of each hydraulic actuator desired by the operator can be quickly obtained.
　ここで、油圧ショベル等の作業機械では、各油圧アクチュエータによって駆動される動作部位毎にその自重や作業対象物の慣性質量、及び作業対象物から受ける反力による負荷等が異なるので、必ずしも各動作部位に対して上述したような同一の特性が求められるとは限らない。例えば、バケットは速度制御性に優れたものが比較的好まれるが、旋回装置やブーム等は速度制御性の他に力制御性についても良好なものが望ましい。 Here, in a working machine such as a hydraulic excavator, each operation part driven by each hydraulic actuator has its own weight, the inertial mass of the work object, and the load due to the reaction force received from the work object. The same characteristics as described above are not always required for the part. For example, a bucket having a relatively high speed controllability is relatively preferred, but a swinging device, a boom, etc. preferably have a good force controllability in addition to the speed controllability.
特開平７－１９７４９１号公報JP-A-7-197491
　上述した特許文献１に開示された従来技術の超小旋回式油圧作業機は、ロードセンシングシステムの制御によって高い速度制御性を得られても、力制御性については考慮されていないので、これらの動作部位のうち、例えば旋回体やブームは慣性負荷や駆動負荷が他の動作部位と比較して大きくなり易く、ロードセンシングシステムの制御下では操作装置の操作入力を受けて旋回体やブームを目標速度に追従させようと駆動力（システム圧力）が大きく変動・振幅することになる。そのため、旋回体やブームの駆動圧力がＯＮ／ＯＦＦ的になり易く、すなわち旋回体やブームが急に動き出したり、あるいは急停止し易くなり、力制御性を確保し難い状況になるので、滑らかな操作感覚が得られないことが問題になっている。 Since the conventional ultra-small turning hydraulic working machine disclosed in Patent Document 1 described above can obtain high speed controllability by controlling the load sensing system, the force controllability is not taken into consideration. Among the operating parts, for example, the swinging body and boom tend to have a larger inertial load and driving load than other operating parts, and under the control of the load sensing system, the turning body and boom are targeted by receiving the operation input of the operating device. The driving force (system pressure) will fluctuate and amplify to follow the speed. Therefore, the driving pressure of the swing body and boom is likely to be ON / OFF, that is, the swing body and boom suddenly start or stop suddenly, and it becomes difficult to ensure force controllability. The problem is that you cannot get a sense of operation.
　特に、従来技術の超小旋回式油圧作業機は、操作者が操作装置を操作することにより各動作部位を動かして作業を行うものであり、速度制御性に優れていても力制御性が得られなければ、旋回体やブームが急に動き出したり、あるいは急停止しないように慎重に操作することが要求されるので、操作装置の操作性能が低下することが懸念されている。 In particular, the conventional ultra-small swivel hydraulic working machine is one in which an operator operates each operating part by operating an operating device, so that even if it has excellent speed controllability, force controllability is obtained. Otherwise, it is required to operate carefully so that the revolving body and boom do not suddenly start or stop suddenly, and there is a concern that the operating performance of the operating device will deteriorate.
　一方、上述した従来技術の超小旋回式油圧作業機のようにロードセンシングシステムが適用された作業機械の各油圧アクチュエータへ流入する作動油の流量制御性は、操作装置の操作入力による方向制御弁のスプールの応答と圧力補償弁の圧力制御の応答で決定される。そのため、方向制御弁のスプールの動作が操作装置の操作入力に対して動的な遅れが生じなければ、作動油の流量制御性は圧力補償弁の圧力制御の応答で決定されるので、圧力補償弁は各油圧アクチュエータの速度に対して速やかに追従する特性を有している。従って、圧力補償弁の圧力制御の応答を自由に設定し、圧力制御弁の動作を各油圧アクチュエータの速度に対して遅らせることができれば、操作装置の操作性能を高めることができるように考えられる。 On the other hand, the flow rate controllability of hydraulic fluid flowing into each hydraulic actuator of a work machine to which a load sensing system is applied, such as the above-described prior art ultra-small turning hydraulic work machine, is a directional control valve based on an operation input of an operating device. This is determined by the response of the spool and the pressure control response of the pressure compensation valve. Therefore, if there is no dynamic delay in the operation of the spool of the directional control valve with respect to the operation input of the operating device, the flow rate controllability of the hydraulic oil is determined by the pressure control response of the pressure compensation valve. The valve has a characteristic of quickly following the speed of each hydraulic actuator. Therefore, if the response of the pressure control of the pressure compensation valve can be freely set and the operation of the pressure control valve can be delayed with respect to the speed of each hydraulic actuator, it is considered that the operation performance of the operating device can be improved.
　しかし、上述の圧力補償弁の追従特性は、圧力補償弁の受圧部分に作用する力、圧力補償弁に作用するばねの弾性力、圧力補償弁の質量、及び圧力伝達回路等の構成部品から成るハードウェア構成に依存し、圧力補償弁は、このような容易に変更できないハードウェア構成によって各油圧アクチュエータの速度に対して素早く動作するので、圧力補償弁の圧力制御の応答を自由に設定することができず、操作装置の操作性能を向上させることが困難になっている。 However, the following characteristics of the pressure compensation valve are composed of components such as the force acting on the pressure receiving portion of the pressure compensation valve, the elastic force of the spring acting on the pressure compensation valve, the mass of the pressure compensation valve, and the pressure transmission circuit. Depending on the hardware configuration, the pressure compensation valve operates quickly with respect to the speed of each hydraulic actuator by such a hardware configuration that cannot be changed easily, so that the pressure control response of the pressure compensation valve can be freely set It is difficult to improve the operating performance of the operating device.
　本発明は、このような従来技術の実情からなされたもので、その目的は、操作装置の操作入力に対して油圧アクチュエータの速度制御性を確保しつつ、力制御性を十分に向上させることができる作業機械の油圧制御装置を提供することにある。 The present invention has been made based on the actual situation of the prior art as described above, and its object is to sufficiently improve the force controllability while ensuring the speed controllability of the hydraulic actuator with respect to the operation input of the operation device. An object of the present invention is to provide a hydraulic control device for a working machine.
　上記の目的を達成するために、本発明の作業機械の油圧制御装置は、原動機により駆動される油圧ポンプと、この油圧ポンプから吐出された作動油によって動作する複数の油圧アクチュエータと、これらの油圧アクチュエータを操作する操作装置とを備えた作業機械に設けられ、前記操作装置による操作入力を受けて前記油圧ポンプから前記複数の油圧アクチュエータへ吐出される作動油の流量を制御する油圧制御部を備えた作業機械の油圧制御装置において、前記油圧ポンプの吐出圧を検出する吐出圧検出部と、前記複数の油圧アクチュエータの速度を検出する速度検出部と、前記複数の油圧アクチュエータへ流入する作動油の圧力を制御する流入制御部と、前記操作装置によって操作された操作量に基づいて、前記複数の油圧アクチュエータを動作させる速度の目標値を演算する目標速度演算部と、前記速度検出部によって検出された前記速度及び前記目標速度演算部によって演算された前記目標値に基づいて、前記複数の油圧アクチュエータを駆動する駆動圧の目標値を演算する目標駆動圧演算部と、前記吐出圧検出部によって検出された前記吐出圧及び前記目標駆動圧演算部によって演算された前記目標値に応じて、前記油圧ポンプの吐出量の目標値を演算する目標吐出量演算部とを備え、前記流入制御部は、前記目標駆動圧演算部によって演算された前記目標値に応じて、前記複数の油圧アクチュエータへ流入する作動油の圧力を制御すると共に、前記油圧制御部は、前記油圧ポンプの前記吐出量を前記目標吐出量演算部によって演算された前記目標値に制御することを特徴としている。 In order to achieve the above object, a hydraulic control device for a work machine according to the present invention includes a hydraulic pump driven by a prime mover, a plurality of hydraulic actuators operated by hydraulic oil discharged from the hydraulic pump, and the hydraulic pressures thereof. A hydraulic control unit that is provided in a work machine including an operation device that operates an actuator, and that controls an operation flow from the hydraulic pump to the plurality of hydraulic actuators in response to an operation input from the operation device; In the hydraulic control device for a working machine, a discharge pressure detection unit that detects a discharge pressure of the hydraulic pump, a speed detection unit that detects a speed of the plurality of hydraulic actuators, and a hydraulic fluid flowing into the plurality of hydraulic actuators And a plurality of hydraulic actuators based on an inflow control unit for controlling pressure and an operation amount operated by the operation device. A plurality of hydraulic actuators based on the target speed calculation unit that calculates a target value of the speed at which the motor is operated, the speed detected by the speed detection unit, and the target value calculated by the target speed calculation unit A target driving pressure calculating unit that calculates a target value of a driving pressure for driving the hydraulic pressure, and the hydraulic pressure according to the discharge pressure detected by the discharge pressure detecting unit and the target value calculated by the target driving pressure calculating unit. A target discharge amount calculation unit that calculates a target value of the pump discharge amount, and the inflow control unit flows into the plurality of hydraulic actuators according to the target value calculated by the target drive pressure calculation unit While controlling the pressure of hydraulic fluid, the hydraulic control unit controls the discharge amount of the hydraulic pump to the target value calculated by the target discharge amount calculation unit. It is characterized.
　このように構成した本発明は、操作装置の操作入力が行われると、目標速度演算部が操作装置によって操作された操作量に基づいて、各油圧アクチュエータを動作させる速度の目標値を演算する。一方、速度検出部が操作装置によって操作される各油圧アクチュエータの速度を検出しているので、目標駆動圧演算部は、この検出された各油圧アクチュエータの速度及び目標速度演算部によって演算された目標値に基づいて、各油圧アクチュエータの駆動圧の目標値を演算することができる。 In the present invention configured as described above, when an operation input of the operation device is performed, the target speed calculation unit calculates the target value of the speed for operating each hydraulic actuator based on the operation amount operated by the operation device. On the other hand, since the speed detector detects the speed of each hydraulic actuator operated by the operating device, the target drive pressure calculator calculates the detected speed of each hydraulic actuator and the target calculated by the target speed calculator. Based on the value, the target value of the driving pressure of each hydraulic actuator can be calculated.
　また、吐出圧検出部が油圧ポンプの吐出圧を検出しているので、吐出量演算部は、この検出された油圧ポンプの吐出圧及び目標駆動圧演算部によって演算された目標値に応じて、油圧ポンプの吐出量の目標値を演算し、油圧制御部が油圧ポンプの吐出量をこの演算された目標値に制御する。これにより、この目標値に相当する流量の作動油が圧油として油圧ポンプから各油圧アクチュエータへ向けて油圧回路内へ吐出されるので、吐出された作動油は各油圧アクチュエータよりも上流側に配置された流入制御部へ流れ込む。このとき、操作装置の操作入力に対して必要とされる流量以上の流量の作動油が各油圧アクチュエータに流れ込もうとしても、流入制御部によって目標駆動圧演算部で演算された目標値となるように圧力、すなわち駆動圧が制御され、その駆動圧に応じた流量に制限されるので、各油圧アクチュエータを適切に動作させることができる。従って、操作装置の操作入力に対して油圧アクチュエータの速度制御性を確保しつつ、力制御性を十分に向上させることができる。 In addition, since the discharge pressure detection unit detects the discharge pressure of the hydraulic pump, the discharge amount calculation unit, according to the detected discharge pressure of the hydraulic pump and the target value calculated by the target drive pressure calculation unit, The target value of the discharge amount of the hydraulic pump is calculated, and the hydraulic control unit controls the discharge amount of the hydraulic pump to the calculated target value. As a result, hydraulic oil having a flow rate corresponding to this target value is discharged as pressure oil from the hydraulic pump toward each hydraulic actuator into the hydraulic circuit, so that the discharged hydraulic oil is arranged upstream of each hydraulic actuator. Flow into the inflow control unit. At this time, even if hydraulic fluid having a flow rate higher than that required for the operation input of the operating device is about to flow into each hydraulic actuator, the target value calculated by the target drive pressure calculation unit by the inflow control unit is obtained. Thus, since the pressure, that is, the driving pressure is controlled and the flow rate is limited to the driving pressure, each hydraulic actuator can be appropriately operated. Therefore, the force controllability can be sufficiently improved while ensuring the speed controllability of the hydraulic actuator with respect to the operation input of the operation device.
　また、本発明に係る作業機械の油圧制御装置は、さらに、前記操作装置によって操作された前記操作量に基づいて、前記駆動圧の上限圧力を設定する圧力制限部を備え、前記目標駆動圧演算部は、前記速度検出部によって検出された前記速度、前記目標速度演算部によって演算された前記目標値、及び前記圧力制限部によって設定された前記駆動圧の上限圧力に基づいて、前記駆動圧の目標値を演算することを特徴としている。 The hydraulic control device for a work machine according to the present invention further includes a pressure limiting unit that sets an upper limit pressure of the driving pressure based on the operation amount operated by the operating device, and the target driving pressure calculation The unit is configured to determine the driving pressure based on the speed detected by the speed detecting unit, the target value calculated by the target speed calculating unit, and an upper limit pressure of the driving pressure set by the pressure limiting unit. It is characterized by calculating a target value.
　このように構成した本発明は、各油圧アクチュエータが操作装置の操作量に対して目標速度演算部によって演算された目標値の速度を得るのに必要とされる駆動圧が、圧力制限部によって設定された駆動圧の上限圧力より大きい場合であっても、この駆動圧の上限圧力を超える圧力が各油圧アクチュエータに作用することがないので、操作装置の操作量に応じて各油圧アクチュエータの駆動力を抑制することができ、高い力制御性を得ることができる。 In the present invention configured as described above, the drive pressure required for each hydraulic actuator to obtain the target value speed calculated by the target speed calculation unit with respect to the operation amount of the operating device is set by the pressure limiting unit. Since the pressure exceeding the upper limit of the drive pressure does not act on each hydraulic actuator even when the upper limit is exceeded, the driving force of each hydraulic actuator depends on the operation amount of the operating device. Can be suppressed, and high force controllability can be obtained.
　一方、各油圧アクチュエータが操作装置の操作量に対して目標速度演算部によって演算された目標値の速度を得るのに必要とされる駆動圧が、圧力制限部によって設定された駆動圧の上限圧力以下である場合には、目標駆動圧演算部の演算過程において圧力制限部による駆動圧の制限を受けず、各油圧アクチュエータの駆動力が抑制されないので、優れた速度制御性を得ることができる。 On the other hand, the driving pressure required for each hydraulic actuator to obtain the target speed calculated by the target speed calculator with respect to the operation amount of the operating device is the upper limit pressure of the driving pressure set by the pressure limiter. In the case of the following, since the drive pressure of the hydraulic actuator is not limited and the drive force of each hydraulic actuator is not suppressed in the calculation process of the target drive pressure calculation unit, excellent speed controllability can be obtained.
　また、本発明に係る作業機械の油圧制御装置は、前記発明において、前記目標駆動圧演算部は、演算した前記駆動圧の前記目標値よりも所定値だけ低い値を演算結果として前記目標吐出量演算部へ出力することを特徴としている。このように構成すると、複数の油圧アクチュエータのうち目標駆動圧演算部によって最も高い目標値が演算された油圧アクチュエータの駆動圧より、油圧ポンプの吐出圧が所定値分低くなるので、その油圧アクチュエータへの駆動圧を制御する流入制御部は開口面積を最大とし、作動油が通過する際に生じる抵抗、すなわち圧力損失を最小限に抑えることができる。 Further, in the hydraulic control device for a work machine according to the present invention, in the above invention, the target drive pressure calculation unit uses the target discharge amount as a calculation result that is a value lower than the target value of the calculated drive pressure by a predetermined value. It is characterized by being output to a calculation unit. With this configuration, the discharge pressure of the hydraulic pump is lower by a predetermined value than the drive pressure of the hydraulic actuator for which the highest target value has been calculated by the target drive pressure calculation unit among the plurality of hydraulic actuators. The inflow control unit that controls the driving pressure of the engine can maximize the opening area, and can minimize resistance generated when hydraulic fluid passes, that is, pressure loss.
　また、本発明に係る作業機械の油圧制御装置は、前記発明において、前記操作装置によって操作される前記操作量と前記目標速度演算部によって演算される前記目標値との関係が予め記憶された記憶部と、この記憶部に記憶された関係を前記目標駆動圧演算部によって演算された前記目標値に応じて補正する関係補正部を備え、前記目標速度演算部は、前記関係補正部によって補正された前記関係に対し、前記操作装置によって操作された前記操作量を適用して前記目標値を演算することを特徴としている。 In the hydraulic control device for a work machine according to the present invention, in the invention described above, the relationship between the operation amount operated by the operation device and the target value calculated by the target speed calculation unit is stored in advance. And a relationship correction unit that corrects the relationship stored in the storage unit according to the target value calculated by the target drive pressure calculation unit, and the target speed calculation unit is corrected by the relationship correction unit. In addition, the target value is calculated by applying the operation amount operated by the operation device to the relationship.
　このように構成した本発明は、目標駆動圧演算部によって演算された目標値から各油圧アクチュエータに必要とされる速度制御性及び力制御性の程度を把握できるので、関係補正部が記憶部に記憶された関係を目標駆動圧演算部によって演算された目標値に応じて補正することにより、油圧アクチュエータ毎に速度制御性及び力制御性の要求が異なっていても、その要求を目標速度演算部による演算に反映させた上で、操作装置の操作量に対して各油圧アクチュエータの速度の目標値を求めることができる。これにより、油圧アクチュエータ毎に操作装置の操作感覚を容易に調整することができる。 In the present invention configured as described above, since the degree of speed controllability and force controllability required for each hydraulic actuator can be grasped from the target value calculated by the target drive pressure calculation unit, the relationship correction unit is stored in the storage unit. By correcting the stored relationship according to the target value calculated by the target drive pressure calculation unit, even if the demands of speed controllability and force controllability differ for each hydraulic actuator, the request is changed to the target speed calculation unit. The target value of the speed of each hydraulic actuator can be obtained with respect to the operation amount of the operating device. Thereby, the operation feeling of the operating device can be easily adjusted for each hydraulic actuator.
　また、本発明に係る作業機械の油圧制御装置は、前記発明において、前記流入制御部は、前記油圧ポンプと前記複数の油圧アクチュエータとの間に設けられ、通過する作動油の圧力を制御する圧力制御弁を含み、前記圧力制御弁は、外部からの入力信号を受信して駆動し、前記入力信号が増加するに従って開口量を減少させることを特徴としている。このように構成すると、複数の油圧アクチュエータへ流入する作動油の流量の制御を、油圧ポンプと複数の油圧アクチュエータとの間に配置された圧力制御弁によって容易に実行できるので、油圧回路が複雑にならず、油圧回路を効率良く製造することができる。また、圧力制御弁が外部からの入力信号を受信していないときでも、圧力制御弁が開口した状態を保つことができるので、操作装置の操作入力に対して油圧アクチュエータを確実に動作させることができる。 Further, in the hydraulic control device for a work machine according to the present invention, in the above invention, the inflow control unit is provided between the hydraulic pump and the plurality of hydraulic actuators, and controls the pressure of hydraulic fluid that passes therethrough. It includes a control valve, and the pressure control valve is driven by receiving an input signal from the outside, and the opening amount is decreased as the input signal increases. With this configuration, the control of the flow rate of the hydraulic oil flowing into the plurality of hydraulic actuators can be easily performed by the pressure control valve disposed between the hydraulic pump and the plurality of hydraulic actuators, so that the hydraulic circuit is complicated. Rather, the hydraulic circuit can be manufactured efficiently. Further, even when the pressure control valve does not receive an external input signal, the pressure control valve can be kept open, so that the hydraulic actuator can be reliably operated in response to the operation input of the operating device. it can.
　本発明の作業機械の油圧制御装置によれば、油圧制御部は、速度検出部で検出された各油圧アクチュエータの速度及び目標速度演算部で演算された速度の目標値に基づいて、目標駆動圧演算部によって演算された目標値に相当する圧力を、目標吐出量制御部で油圧ポンプの吐出量を調整して流入制御部を介して各油圧アクチュエータに適切に作用させることができる。そのため、操作装置の操作量に応じて各油圧アクチュエータの駆動力を抑制することができ、操作装置の操作入力に対して油圧アクチュエータの速度制御性を確保しつつ、力制御性を十分に向上させることができる。これにより、各油圧アクチュエータの安定した動作を実現でき、滑らかな操作感覚が得られるので、操作装置の操作性能を高めることができ、従来よりも作業機械の作業効率を高めることができる。 According to the hydraulic control device for a work machine of the present invention, the hydraulic control unit is configured to generate a target drive pressure based on the speed of each hydraulic actuator detected by the speed detection unit and the target value of the speed calculated by the target speed calculation unit. The pressure corresponding to the target value calculated by the calculation unit can be appropriately applied to each hydraulic actuator via the inflow control unit by adjusting the discharge amount of the hydraulic pump by the target discharge amount control unit. Therefore, the driving force of each hydraulic actuator can be suppressed according to the operation amount of the operating device, and the force controllability is sufficiently improved while ensuring the speed controllability of the hydraulic actuator for the operation input of the operating device. be able to. Accordingly, stable operation of each hydraulic actuator can be realized, and a smooth operation feeling can be obtained. Therefore, the operation performance of the operation device can be improved, and the work efficiency of the work machine can be improved as compared with the conventional case.
本発明に係る油圧制御装置の第１実施形態が備えられる作業機械の一例として挙げた油圧ショベルを示す図である。It is a figure showing a hydraulic excavator mentioned as an example of a working machine with which a 1st embodiment of a hydraulic control device concerning the present invention is provided. 本発明に係る作業機械の油圧制御装置の第１実施形態の構成を示す図である。It is a figure showing composition of a 1st embodiment of a hydraulic control device of a working machine concerning the present invention. 本発明の第１実施形態に備えられたコントローラの構成を示す図である。It is a figure which shows the structure of the controller with which 1st Embodiment of this invention was equipped. 図３に示すコントローラの要部を示す図であり、特に旋回モータに関する目標速度テーブル及び上限圧力テーブルの各関数関係を説明する図である。It is a figure which shows the principal part of the controller shown in FIG. 3, and is a figure explaining each functional relationship of the target speed table regarding an especially turning motor, and an upper limit pressure table. 図３に示すコントローラの要部を示す図であり、特にブームシリンダに関する目標速度テーブル及び上限圧力テーブルの各関数関係を説明する図である。It is a figure which shows the principal part of the controller shown in FIG. 3, and is a figure explaining each function relationship of the target speed table and upper limit pressure table regarding especially a boom cylinder. 本発明の第１実施形態に備えられた流入制御部について説明する図であり、（ａ）図は流入制御部を構成する電磁比例減圧弁の構成を示す図、（ｂ）図は電磁比例減圧弁の特性を示す図である。It is a figure explaining the inflow control part with which 1st Embodiment of this invention was equipped, (a) A figure shows the structure of the electromagnetic proportional pressure reducing valve which comprises an inflow control part, (b) The figure is an electromagnetic proportional pressure reduction. It is a figure which shows the characteristic of a valve. 本発明の第２実施形態に備えられたコントローラの構成を示す図である。It is a figure which shows the structure of the controller with which 2nd Embodiment of this invention was equipped. 本発明の第２実施形態に備えられた関係補正部によって補正された旋回モータに関する目標速度テーブルの関数関係を説明する図である。It is a figure explaining the functional relationship of the target speed table regarding the turning motor correct | amended by the relationship correction | amendment part with which 2nd Embodiment of this invention was equipped. 本発明の第２実施形態に備えられた関係補正部によって補正されたブームシリンダに関する目標速度テーブルの関数関係を説明する図である。It is a figure explaining the functional relationship of the target speed table regarding the boom cylinder correct | amended by the relationship correction | amendment part with which 2nd Embodiment of this invention was equipped. 本発明の第３実施形態に備えられた流入制御部について説明する図であり、（ａ）図は流入制御部を構成する電磁比例絞り弁の構成を示す図、（ｂ）図は電磁比例絞り弁の特性を示す図である。It is a figure explaining the inflow control part with which 3rd Embodiment of this invention was equipped, (a) A figure shows the structure of the electromagnetic proportional throttle valve which comprises an inflow control part, (b) The figure is an electromagnetic proportional throttle It is a figure which shows the characteristic of a valve. 本発明の第３実施形態に備えられたコントローラの構成を示す図である。It is a figure which shows the structure of the controller with which 3rd Embodiment of this invention was equipped.
　以下、本発明に係る作業機械の油圧制御装置を実施するための形態を図に基づいて説明する。 Hereinafter, an embodiment for implementing a hydraulic control device for a work machine according to the present invention will be described with reference to the drawings.
［第１実施形態］
　本発明に係る油圧制御装置の第１実施形態は、作業機械、例えば図１に示す油圧ショベル１に適用される。この油圧ショベル１は、走行体２と、この走行体２の上側に旋回装置３Ａを介して旋回可能に取付けられた旋回体３と、この旋回体３の前方に取り付けられて上下方向に回動するフロント作業機４とから構成されている。 [First Embodiment]
The first embodiment of the hydraulic control apparatus according to the present invention is applied to a work machine, for example, a hydraulic excavator 1 shown in FIG. The hydraulic excavator 1 includes a traveling body 2, a revolving body 3 attached to the upper side of the traveling body 2 via a revolving device 3A, and a revolving body 3 mounted in front of the revolving body 3 so as to rotate in the vertical direction. The front work machine 4 is configured.
　このフロント作業機４は、基端が旋回体３に回動可能に取り付けられて上下方向に回動するブーム４Ａと、このブーム４Ａの先端に回動可能に取り付けられたアーム４Ｂと、このアーム４Ｂの先端に回動可能に取り付けられたバケット４Ｃとを有している。旋回体３は、前方に配置されたキャブ７と、後方に配置され、車体のバランスを保つカウンタウェイト６と、これらキャブ７とカウンタウェイト６との間に配置され、原動機としてのエンジン１１（図２参照）を格納するエンジンルーム５と、このエンジンルーム５内のエンジン１１に取り付けられ、エンジン１１の回転数を検出するエンジン回転数検出部１１Ａ（図２参照）とを備えている。 The front work machine 4 includes a boom 4A whose base end is pivotally attached to the swing body 3 and pivots in the vertical direction, an arm 4B pivotally attached to the tip of the boom 4A, and the arm And a bucket 4C rotatably attached to the tip of 4B. The swivel body 3 is arranged at the front, a cab 7 disposed at the rear, a counterweight 6 disposed at the rear to maintain the balance of the vehicle body, and disposed between the cab 7 and the counterweight 6, and an engine 11 (see FIG. 2) and an engine speed detector 11A (see FIG. 2) that is attached to the engine 11 in the engine room 5 and detects the speed of the engine 11.
　旋回体３は、例えば図２に示すようにエンジン１１の駆動力で回転し、フロント作業機４を駆動する圧油として作動油を吐出する可変容量型斜板式油圧ポンプ（以下、便宜的に油圧ポンプと呼ぶ）１２とを備え、この油圧ポンプ１２の回転軸に対する斜板（図示せず）の傾転角を変更して傾転量を調整する傾転量調整部１２Ａと、油圧ポンプ１２に吸入される作動油を貯蔵する作動油タンク１３と、この油圧ポンプ１２から吐出された作動油によって動作する複数の油圧アクチュエータとを有している。なお、油圧ポンプ１２は、斜板式に拘るものでなく、斜軸式など他の可変容量型機構を用いてもよい。 For example, as shown in FIG. 2, the rotating body 3 is rotated by a driving force of the engine 11, and a variable displacement swash plate hydraulic pump (hereinafter referred to as hydraulic pressure for convenience) that discharges hydraulic oil as pressure oil for driving the front work machine 4. (Referred to as a pump) 12, a tilt amount adjusting unit 12 A that adjusts the tilt amount by changing the tilt angle of a swash plate (not shown) with respect to the rotating shaft of the hydraulic pump 12, and the hydraulic pump 12 A hydraulic oil tank 13 that stores the hydraulic oil to be sucked in and a plurality of hydraulic actuators that are operated by the hydraulic oil discharged from the hydraulic pump 12. The hydraulic pump 12 is not limited to the swash plate type, and other variable displacement mechanisms such as a swash shaft type may be used.
　これらの油圧アクチュエータは、例えば旋回装置３Ａを駆動する旋回モータ３ａと、旋回体３とブーム４Ａとを接続し、伸縮することによってブーム４Ａを回動させるブームシリンダ４ａと、ブーム４Ａの上側に配置されると共にブーム４Ａとアーム４Ｂとを接続し、伸縮することによってアーム４Ｂを回動させるアームシリンダ４ｂと、アーム４Ｂとバケット４Ｃとを接続し、伸縮することによってバケット４Ｃを回動させるバケットシリンダ４ｃとを含んでいる。 These hydraulic actuators are arranged on the upper side of the boom 4A, for example, a swing motor 3a that drives the swing device 3A, a swing cylinder 3 that connects the swing body 3 and the boom 4A, and rotates the boom 4A by extending and contracting. At the same time, the boom cylinder 4A and the arm 4B are connected, and the arm cylinder 4b that rotates the arm 4B by extending and contracting, and the bucket cylinder that connects the arm 4B and the bucket 4C and rotating the bucket 4C by expanding and contracting. 4c.
　また、旋回体３は、油圧ポンプ１２と各旋回モータ３ａ、ブームシリンダ４ａ、アームシリンダ４ｂ、及びバケットシリンダ４ｃとの間に接続され、油圧ポンプ１２から吐出された作動油の流れを制御する方向制御弁１６Ａ～１６Ｄを有している。なお、各方向制御弁１６Ａ～１６Ｄは、例えばセンタバイパス油路がないクローズドセンタ型であり、ブリードオフ回路を備えていないものである。 Further, the swing body 3 is connected between the hydraulic pump 12 and each swing motor 3a, the boom cylinder 4a, the arm cylinder 4b, and the bucket cylinder 4c, and controls the flow of hydraulic oil discharged from the hydraulic pump 12. Control valves 16A to 16D are provided. Each of the directional control valves 16A to 16D is, for example, a closed center type having no center bypass oil passage and does not include a bleed-off circuit.
　キャブ７は、操作者が着座する運転シート（図示せず）と、この運転シートの近傍に設けられ、各油圧アクチュエータ３ａ，４ａ～４ｃを操作する操作装置を有し、この操作装置は、例えば運転シートの左側方に配置され、旋回装置３Ａを左右に旋回させたり、あるいはアームを上下方向に回動させる操作を行う左操作レバー１５Ａと、運転席の右側方に配置され、ブーム４Ａを上下方向に回動させたり、あるいはバケット４Ｃを上下方向に回動させる操作を行う右操作レバー１５Ｂと、作動油タンク１３に接続され、左操作レバー１５Ａ及び右操作レバー１５Ｂへパイロット圧油として作動油を供給するパイロットポンプ（図示せず）とを含んでいる。 The cab 7 includes an operation seat (not shown) on which an operator is seated, and an operation device that is provided in the vicinity of the operation seat and operates each of the hydraulic actuators 3a, 4a to 4c. A left operation lever 15A that is disposed on the left side of the driver's seat and that rotates the swivel device 3A to the left or right, or that rotates the arm in the vertical direction. Connected to the right operating lever 15B and the hydraulic oil tank 13 for rotating the bucket 4C or rotating the bucket 4C in the vertical direction, and operating oil as pilot pressure oil to the left operating lever 15A and the right operating lever 15B. And a pilot pump (not shown).
　左操作レバー１５Ａは、例えば旋回モータ３ａ側の方向制御弁１６Ａの左右の受圧室にそれぞれ接続されており、パイロットポンプから導かれたパイロット圧油を前後左右の四方のうち左右方向の操作入力を受け、操作量に応じて方向制御弁１６Ａの各受圧室へ供給するパイロット圧油の圧力、すなわちパイロット圧を調整し、パイロット圧を方向制御弁１６Ａに作用させて方向制御弁１６Ａの切換位置を切り替えるようにしている。 The left operation lever 15A is connected to, for example, the left and right pressure receiving chambers of the directional control valve 16A on the swing motor 3a side. The pressure of pilot pressure oil supplied to each pressure receiving chamber of the direction control valve 16A, that is, the pilot pressure is adjusted according to the amount of operation and received, and the pilot pressure is applied to the direction control valve 16A to change the switching position of the direction control valve 16A. I try to switch.
　また、左操作レバー１５Ａは、例えばアームシリンダ４ｂ側の方向制御弁１６Ｃの左右の受圧室にそれぞれ接続されており、パイロットポンプから導かれたパイロット圧油を前後左右の四方のうち前後方向の操作入力を受け、操作量に応じて方向制御弁１６Ｃの各受圧室へ供給するパイロット圧を調整し、パイロット圧を方向制御弁１６Ｃに作用させて方向制御弁１６Ｃの切換位置を切り替えるようにしている。従って、操作者は、左操作レバー１５Ａを左右方向へ操作することにより、旋回装置３Ａを左右に旋回させたり、あるいは左操作レバー１５Ａを前後方向へ操作することにより、アーム４Ｂを上下方向に回動させることができる。 Further, the left operation lever 15A is connected to, for example, the left and right pressure receiving chambers of the direction control valve 16C on the arm cylinder 4b side, and the pilot pressure oil guided from the pilot pump is operated in the front / rear direction among the front / rear and left / right directions. The pilot pressure supplied to each pressure receiving chamber of the direction control valve 16C is adjusted according to the operation amount, and the pilot pressure is applied to the direction control valve 16C to switch the switching position of the direction control valve 16C. . Therefore, the operator rotates the arm 4B in the vertical direction by operating the left operation lever 15A in the left-right direction to turn the turning device 3A in the left-right direction, or operating the left operation lever 15A in the front-rear direction. Can be moved.
　右操作レバー１５Ｂは、例えばブームシリンダ４ａ側の方向制御弁１６Ｂの左右の受圧室にそれぞれ接続されており、パイロットポンプから導かれたパイロット圧油を前後左右の四方のうち前後方向の操作入力を受け、操作量に応じて方向制御弁１６Ｂの各受圧室へ供給するパイロット圧を調整し、パイロット圧を方向制御弁１６Ｂに作用させて方向制御弁１６Ｂの切換位置を切り替えるようにしている。 The right operation lever 15B is connected to the left and right pressure receiving chambers of the direction control valve 16B on the boom cylinder 4a side, for example, and inputs pilot pressure oil guided from the pilot pump in the front / rear direction among the front / rear and left / right directions. The pilot pressure supplied to each pressure receiving chamber of the direction control valve 16B is adjusted according to the amount of operation received, and the pilot pressure is applied to the direction control valve 16B to switch the switching position of the direction control valve 16B.
　また、右操作レバー１５Ｂは、例えばバケットシリンダ４ｃ側の方向制御弁１６Ｄの左右の受圧室にそれぞれ接続されており、操作量に応じて方向制御弁１６Ｄの各受圧室へ供給するパイロット圧を調整し、パイロット圧を方向制御弁１６Ｄに作用させて方向制御弁１６Ｄの切換位置を切り替えるようにしている。従って、操作者は、右操作レバー１５Ｂを前後方向へ操作することにより、ブーム４Ａを上下方向に回動させたり、あるいは右操作レバー１５Ｂを左右方向へ操作することにより、バケット４Ｃを上下方向に回動させることができる。なお、各操作レバー１５Ａ，１５Ｂの操作量は、例えば操作方向が左方向又は前方向のときに正の値となり、各操作レバー１５Ａ，１５Ｂの操作方向が右方向又は後方向のときに負の値となる。 The right operation lever 15B is connected to, for example, the left and right pressure receiving chambers of the direction control valve 16D on the bucket cylinder 4c side, and adjusts the pilot pressure supplied to each pressure receiving chamber of the direction control valve 16D according to the operation amount. The pilot pressure is applied to the direction control valve 16D to switch the switching position of the direction control valve 16D. Therefore, the operator operates the right operation lever 15B in the front-rear direction to rotate the boom 4A in the vertical direction, or operates the right operation lever 15B in the left-right direction to move the bucket 4C in the vertical direction. It can be rotated. The operation amount of each operation lever 15A, 15B is a positive value when, for example, the operation direction is the left direction or the front direction, and is negative when the operation direction of each operation lever 15A, 15B is the right direction or the rear direction. Value.
　また、左操作レバー１５Ａ及び右操作レバー１５Ｂには、操作量を検出する操作量検出部としての操作量センサ１５Ａ１，１５Ｂ１がそれぞれ設けられており、これらの各操作量センサ１５Ａ１，１５Ｂ１は、操作レバー１５Ａ，１５Ｂから方向制御弁１６Ａ～１６Ｄの各受圧室へ供給されるパイロット圧油のパイロット圧を操作量として検出している。 The left operation lever 15A and the right operation lever 15B are provided with operation amount sensors 15A1 and 15B1 as operation amount detection units for detecting an operation amount, respectively. The pilot pressure of the pilot pressure oil supplied from the levers 15A and 15B to the pressure receiving chambers of the direction control valves 16A to 16D is detected as an operation amount.
　本発明の第１実施形態は、各方向制御弁１６Ａ～１６Ｄと油圧ポンプ１２とを接続する管路に設けられ、油圧ポンプ１２の吐出圧を検出する吐出圧検出部としての吐出圧センサ１７と、各油圧アクチュエータ３ａ，４ａ～４ｃの速度を検出する速度検出部としての速度センサ１８Ａ～１８Ｄと、各油圧アクチュエータ３ａ，４ａ～４ｃへ流入する作動油の圧力、すなわち駆動圧を制御する流入制御部１９Ａ～１９Ｄと、油圧ポンプ１２と各流入制御部１９Ａ～１９Ｄとの間に接続され、油圧ポンプ１２から吐出される作動油が過剰となった場合に、作動油を作動油タンク１３へ流出させるリリーフ弁２１とを有している。 In the first embodiment of the present invention, a discharge pressure sensor 17 serving as a discharge pressure detection unit for detecting the discharge pressure of the hydraulic pump 12 is provided in a pipe line connecting the directional control valves 16A to 16D and the hydraulic pump 12. , Speed sensors 18A to 18D as speed detectors for detecting the speeds of the hydraulic actuators 3a and 4a to 4c, and inflow control for controlling the pressure of hydraulic oil flowing into the hydraulic actuators 3a and 4a to 4c, that is, driving pressure. When the hydraulic fluid discharged from the hydraulic pump 12 becomes excessive, it is connected between the hydraulic pump 12 and the inflow control units 19A to 19D. And a relief valve 21 to be operated.
　そして、本発明の第１実施形態は、各操作レバー１５Ａ，１５Ｂによる操作入力を受けて油圧ポンプ１２から各油圧アクチュエータ３ａ，４ａ～４ｃへ吐出される作動油の流量を制御する油圧制御部としてのコントローラ２０を備えており、このコントローラ２０には、操作量センサ１５Ａ１，１５Ｂ１、吐出圧センサ１７、速度センサ１８Ａ～１８Ｄ、傾転量調整部１２Ａ、及び流入制御部１９Ａ～１９Ｄが接続されている。 The first embodiment of the present invention is a hydraulic control unit that controls the flow rate of hydraulic oil discharged from the hydraulic pump 12 to the hydraulic actuators 3a, 4a to 4c in response to operation inputs from the operation levers 15A and 15B. The controller 20 is connected to operation amount sensors 15A1 and 15B1, a discharge pressure sensor 17, speed sensors 18A to 18D, a tilt amount adjustment unit 12A, and inflow control units 19A to 19D. Yes.
　以下、本発明の第１実施形態に係るコントローラ２０の構成について図３を参照して詳細に説明するが、アームシリンダ４ｂとバケットシリンダ４ｃの制御はブームシリンダ４ａの制御と同様に行われるので、アームシリンダ４ｂとバケットシリンダ４ｃの制御に関する構成及び動作の説明を省略している。 Hereinafter, the configuration of the controller 20 according to the first embodiment of the present invention will be described in detail with reference to FIG. 3, but the control of the arm cylinder 4b and the bucket cylinder 4c is performed similarly to the control of the boom cylinder 4a. A description of the configuration and operation related to the control of the arm cylinder 4b and the bucket cylinder 4c is omitted.
　コントローラ２０は、図３に示すように左操作レバー１５Ａによって操作された操作量、すなわち操作量センサ１５Ａ１によって検出された操作量に基づいて、旋回モータ３ａを動作させる速度の目標値（以下、便宜的に目標旋回速度と呼ぶ）を演算する目標速度演算部２５Ａ１と、操作量センサ１５Ａ１によって操作された操作量に基づいて、旋回モータ３ａを駆動する駆動圧（以下、便宜的に旋回駆動圧と呼ぶ）の上限圧力を設定する圧力制限部２５Ａ２と、速度センサ１８Ａによって検出された旋回モータ３ａの速度、目標速度演算部２５Ａ１によって演算された目標旋回速度、及び圧力制限部２５Ａ２によって設定された旋回駆動圧の上限圧力に基づいて、旋回モータ３ａの駆動圧の目標値（以下、便宜的に目標旋回駆動圧と呼ぶ）を演算する目標駆動圧演算部２６Ａとを有している。なお、圧力制限部２５Ａ２は有することに拘らず、無い構成としてもよい。 As shown in FIG. 3, the controller 20 sets a target value (hereinafter referred to as a convenience) of a speed at which the turning motor 3a is operated based on an operation amount operated by the left operation lever 15A, that is, an operation amount detected by the operation amount sensor 15A1. (Referred to as a target turning speed) and a driving pressure for driving the turning motor 3a based on the operation amount operated by the operation amount sensor 15A1 (hereinafter referred to as a turning driving pressure for convenience). Pressure limiter 25A2 for setting the upper limit pressure), the speed of the swing motor 3a detected by the speed sensor 18A, the target swing speed calculated by the target speed calculator 25A1, and the swing set by the pressure limiter 25A2. Based on the upper limit pressure of the drive pressure, the target value of the drive pressure of the swing motor 3a (hereinafter referred to as the target swing drive pressure for convenience). And a target driving pressure calculating section 26A for calculating a. Note that the pressure limiter 25A2 may be omitted regardless of whether the pressure limiter 25A2 is included.
　コントローラ２０は、右操作レバー１５Ｂによって操作された操作量、すなわち操作量センサ１５Ｂ１によって検出された操作量に基づいて、ブームシリンダ４ａを動作させる速度の目標値（以下、便宜的に目標ブーム速度と呼ぶ）を演算する目標速度演算部２５Ｂ１と、操作量センサ１５Ｂ１によって検出された操作量に基づいて、ブームシリンダ４ａを駆動する駆動圧（以下、便宜的にブーム駆動圧と呼ぶ）の上限圧力を設定する圧力制限部２５Ｂ２と、速度センサ１８Ｂによって検出されたブームシリンダ４ａの速度、目標速度演算部２５Ｂ１によって演算された目標ブーム速度、及び圧力制限部２５Ｂ２によって設定されたブーム駆動圧の上限圧力に基づいて、ブームシリンダ４ａの駆動圧の目標値（以下、便宜的に目標ブーム駆動圧と呼ぶ）を演算する目標駆動圧演算部２６Ｂとを有している。なお、圧力制限部２５Ｂ２は有することに拘らず、無い構成としてもよい。 Based on the operation amount operated by the right operation lever 15B, that is, the operation amount detected by the operation amount sensor 15B1, the controller 20 sets a target value of the speed for operating the boom cylinder 4a (hereinafter referred to as a target boom speed for convenience). The upper limit pressure of the driving pressure for driving the boom cylinder 4a (hereinafter referred to as the boom driving pressure for convenience) is determined based on the operation amount detected by the target speed calculation unit 25B1 and the operation amount sensor 15B1. The speed limit unit 25B2 to be set, the speed of the boom cylinder 4a detected by the speed sensor 18B, the target boom speed calculated by the target speed calculation unit 25B1, and the upper limit pressure of the boom drive pressure set by the pressure limit unit 25B2 Based on the target value of the drive pressure of the boom cylinder 4a (hereinafter, the target boom drive And a target driving pressure calculating unit 26B for calculating referred to as pressure). Note that the pressure limiter 25B2 may be omitted regardless of whether the pressure limiter 25B2 is included.
　コントローラ２０は、吐出圧センサ１７によって検出された油圧ポンプ１２の吐出圧、及び目標駆動圧演算部２６Ａ，２６Ｂによって演算された目標旋回駆動圧と目標ブーム駆動圧に応じて、油圧ポンプ１２の吐出量の目標値（以下、便宜的に目標吐出量と呼ぶ）を演算する目標吐出量演算部３０を備えている。 The controller 20 discharges the hydraulic pump 12 according to the discharge pressure of the hydraulic pump 12 detected by the discharge pressure sensor 17 and the target swing drive pressure and target boom drive pressure calculated by the target drive pressure calculation units 26A and 26B. A target discharge amount calculation unit 30 for calculating a target value of the amount (hereinafter referred to as a target discharge amount for convenience) is provided.
　そして、流入制御部１９Ａ，１９Ｂは、目標駆動圧演算部２６Ａ，２６Ｂによって演算された目標旋回駆動圧及び目標ブーム駆動圧に応じて、各旋回モータ３ａ及びブームシリンダ４ａへ流入する作動油の圧力、すなわち駆動圧を制御し、その駆動圧に応じた流量を設定すると共に、コントローラ２０は、油圧ポンプ１２の吐出量を目標吐出量演算部３０によって演算された目標吐出量に制御するようにしている。なお、上述したように流入制御部１９Ａ，１９Ｂが各旋回モータ３ａ及びブームシリンダ４ａへ流入する作動油の流量を設定しているので、各方向制御弁１６Ａ，１６Ｂは、各アクチュエータ３ａ，４ａの動作方向を定めるため、作動油の流出方向の切替えを主機能とし、通常の方向制御弁が有する各アクチュエータ３ａ，４ａに対する流量設定のための絞り機能は、その影響を小さくしている。 And inflow control part 19A, 19B is the pressure of the hydraulic fluid which flows in into each turning motor 3a and boom cylinder 4a according to the target turning drive pressure and target boom drive pressure which were calculated by target drive pressure calculating part 26A, 26B. That is, the controller 20 controls the drive pressure and sets the flow rate according to the drive pressure, and the controller 20 controls the discharge amount of the hydraulic pump 12 to the target discharge amount calculated by the target discharge amount calculation unit 30. Yes. As described above, since the inflow control units 19A and 19B set the flow rates of the hydraulic oil flowing into the swing motors 3a and the boom cylinders 4a, the directional control valves 16A and 16B are connected to the actuators 3a and 4a. In order to determine the operation direction, the main function is to switch the direction of hydraulic oil outflow, and the throttle function for setting the flow rate for each actuator 3a, 4a of the normal directional control valve reduces the influence.
　次に、本発明の第１実施形態に係る目標速度演算部２５Ａ１，２５Ｂ１、圧力制限部２５Ａ２，２５Ｂ２、目標駆動圧演算部２６Ａ，２６Ｂ、目標吐出量演算部３０、及び流入制御部１９Ａ，１９Ｂの具体的な構成について説明する。 Next, target speed calculation units 25A1, 25B1, pressure limiting units 25A2, 25B2, target drive pressure calculation units 26A, 26B, target discharge amount calculation unit 30, and inflow control units 19A, 19B according to the first embodiment of the present invention. The specific configuration of will be described.
　本発明の第１実施形態は、左操作レバー１５Ａによって操作される操作量と目標速度演算部２５Ａ１によって演算される目標旋回速度との関係として、例えば図４に示す目標速度テーブル２５ａ１を予め記憶した記憶部２５ａ３を備え、この記憶部２５ａ３は、例えば目標速度演算部２５Ａ１の内部に格納されている。 In the first embodiment of the present invention, for example, a target speed table 25a1 shown in FIG. 4 is stored in advance as the relationship between the operation amount operated by the left operation lever 15A and the target turning speed calculated by the target speed calculation unit 25A1. A storage unit 25a3 is provided, and this storage unit 25a3 is stored, for example, inside the target speed calculation unit 25A1.
　この目標速度演算部２５Ａ１の目標速度テーブル２５ａ１は、操作量ＸＬが大きくなるに従って目標旋回速度ＶＲが増加する関数関係を有し、この関数関係は、旋回体３の旋回動作に対して左右同等の性能が要求されることを考慮して原点（ＸＬ＝０，ＶＲ＝０）を中心とする点対象に設定されている。なお、目標速度テーブル２５ａ１の関数関係における目標旋回速度ＶＲが負の値のときの速度は、目標旋回速度ＶＲが正の値のときの速度に対して逆方向であることを示している。 The target speed table 25a1 of the target speed calculation unit 25A1 has a functional relationship in which the target turning speed VR increases as the operation amount XL increases. Considering that performance is required, it is set as a point target centered on the origin (XL = 0, VR = 0). Note that the speed when the target turning speed VR in the functional relationship of the target speed table 25a1 is a negative value indicates that the speed is opposite to the speed when the target turning speed VR is a positive value.
　また、目標速度テーブル２５ａ１の関数関係は、最小値ＶＲｍｉｎ及び最大値ＶＲｍａｘを有し、操作量ＸＬの絶対値が大きくなるに従って操作量ＸＬに対する目標旋回速度ＶＲの傾きの絶対値が段階的に増加するように設定されている。目標速度演算部２５Ａ１は、このように設定された目標速度テーブル２５ａ１の関数関係に対し、操作量センサ１５Ａ１によって検出された操作量を適用して目標旋回速度を演算するようにしている。 The functional relationship of the target speed table 25a1 has a minimum value VRmin and a maximum value VRmax, and the absolute value of the slope of the target turning speed VR with respect to the operation amount XL increases stepwise as the absolute value of the operation amount XL increases. It is set to be. The target speed calculation unit 25A1 calculates the target turning speed by applying the operation amount detected by the operation amount sensor 15A1 to the functional relationship of the target speed table 25a1 set in this way.
　本発明の第１実施形態は、左操作レバー１５Ａによって操作される操作量と圧力制限部２５Ａ２によって設定される旋回駆動圧の上限圧力との関係として、例えば図４に示す上限圧力テーブル２５ａ２を予め記憶した記憶部２５ａ４を備え、この記憶部２５ａ４は、例えば圧力制限部２５Ａ２の内部に格納されている。 In the first embodiment of the present invention, for example, an upper limit pressure table 25a2 shown in FIG. 4 is previously stored as the relationship between the operation amount operated by the left operation lever 15A and the upper limit pressure of the turning drive pressure set by the pressure limiting unit 25A2. The storage unit 25a4 is stored, and the storage unit 25a4 is stored, for example, inside the pressure limiting unit 25A2.
　圧力制限部２５Ａ２の上限圧力テーブル２５ａ２は、操作量ＸＬの絶対値が大きくなるに従って旋回駆動圧の上限圧力ＰＲが増加する関数関係を有し、この関数関係は、旋回体３の旋回動作が左右同等の性能が要求されることを考慮して旋回駆動圧の上限圧力ＰＲ軸（ＸＬ＝０）に対して線対象に設定されている。 The upper limit pressure table 25a2 of the pressure limiting unit 25A2 has a functional relationship in which the upper limit pressure PR of the swing drive pressure increases as the absolute value of the manipulated variable XL increases. Considering that the equivalent performance is required, the upper limit pressure PR axis (XL = 0) of the swing drive pressure is set as a line target.
　また、上限圧力テーブル２５ａ２の関数関係は、最小値ＰＲｍｉｎ（＞０）及び最大値ＰＲｍａｘを有し、操作量ＸＬの絶対値が大きくなるに従って操作量ＸＬに対する旋回駆動圧の上限圧力ＰＲの傾きの絶対値が段階的に増加するように設定されている。圧力制限部２５Ａ２は、このように設定された上限圧力テーブル２５ａ２の関数関係に対し、操作量センサ１５Ａ１によって検出された操作量を適用して旋回駆動圧の上限圧力を設定するようにしている。 Further, the functional relationship of the upper limit pressure table 25a2 has a minimum value PRmin (> 0) and a maximum value PRmax, and the slope of the upper limit pressure PR of the swing drive pressure with respect to the operation amount XL increases as the absolute value of the operation amount XL increases. The absolute value is set to increase stepwise. The pressure limiter 25A2 sets the upper limit pressure of the turning drive pressure by applying the operation amount detected by the operation amount sensor 15A1 to the functional relationship of the upper limit pressure table 25a2 set in this way.
　目標駆動圧演算部２６Ａは、速度センサ１８Ａによって検出された旋回モータ３ａの速度と目標速度演算部２５Ａ１によって演算された目標旋回速度との偏差、すなわち速度偏差に基づいて、比例制御、微分制御、及び積分制御を組み合わせたＰＩＤ制御を行うＰＩＤ制御部２６Ａ１と、このＰＩＤ制御部２６Ａ１及び圧力制限部２５Ａ２に接続され、ＰＩＤ制御部２６Ａ１の出力値に対して圧力制限部２５Ａ２によって設定された旋回駆動圧の上限圧力の制限を加えるリミッタ処理を施すリミッタ処理部２６Ａ２とを有している。 The target drive pressure calculator 26A is configured to perform proportional control, differential control, based on the deviation between the speed of the swing motor 3a detected by the speed sensor 18A and the target swing speed calculated by the target speed calculator 25A1, that is, the speed deviation. And a PID control unit 26A1 that performs PID control combined with integral control, and a turning drive connected to the PID control unit 26A1 and the pressure limiting unit 25A2 and set by the pressure limiting unit 25A2 with respect to the output value of the PID control unit 26A1 And a limiter processing unit 26A2 for performing a limiter process for limiting the upper limit pressure.
　ＰＩＤ制御部２６Ａ１は、速度センサ１８Ａによって検出された旋回モータ３ａの速度と目標速度演算部２５Ａ１によって演算された目標旋回速度に対してＰＩＤ制御を行うことにより、速度偏差が解消する、すなわち旋回モータ３ａの速度を目標旋回速度に一致させるのに必要とされる旋回駆動圧を演算してリミッタ処理部２６Ａ２へ出力するようにしている。なお、ＰＩＤ制御部２６Ａ１はＰＩＤ制御を用いているが、目標値に対して出力値を追従させることができる制御方式であれば良く、ＰＩＤに拘るものではない。 The PID controller 26A1 eliminates the speed deviation by performing PID control on the speed of the swing motor 3a detected by the speed sensor 18A and the target swing speed calculated by the target speed calculator 25A1, that is, the swing motor. The turning driving pressure required to make the speed 3a coincide with the target turning speed is calculated and output to the limiter processing unit 26A2. The PID control unit 26A1 uses PID control, but any control method can be used as long as the output value can follow the target value, and the PID control unit 26A1 is not limited to PID.
　リミッタ処理部２６Ａ２は、ＰＩＤ制御部２６Ａ１によって演算された旋回駆動圧と圧力制限部２５Ａ２によって設定された旋回駆動圧の上限圧力とを比較し、ＰＩＤ制御部２６Ａ１によって演算された旋回駆動圧が圧力制限部２５Ａ２によって設定された旋回駆動圧の上限圧力よりも大きければ、圧力制限部２５Ａ２によって設定された旋回駆動圧の上限圧力を目標旋回駆動圧とする演算を行うようにしている。 The limiter processing unit 26A2 compares the turning drive pressure calculated by the PID control unit 26A1 with the upper limit pressure of the turning drive pressure set by the pressure limiting unit 25A2, and the turning drive pressure calculated by the PID control unit 26A1 is the pressure. If the upper limit pressure of the turning drive pressure set by the restriction unit 25A2 is greater than the upper limit pressure of the turning drive pressure, the calculation is performed with the upper limit pressure of the turning drive pressure set by the pressure restriction unit 25A2 as the target turning drive pressure.
　一方、リミッタ処理部２６Ａ２は、ＰＩＤ制御部２６Ａ１で演算された旋回駆動圧が圧力制限部２５Ａ２によって設定された旋回駆動圧の上限圧力以下であれば、ＰＩＤ制御部２６Ａ１によって演算された旋回駆動圧を目標旋回駆動圧とする演算を行うようにしている。なお、上述した旋回駆動圧の上限圧力の最大値ＰＲｍａｘは、ＰＩＤ制御部２６Ａ１で演算される旋回駆動圧よりも大きくなるように設定されている。また、リミッタ処理部２６Ａ２は、演算した目標旋回駆動圧を流入制御部１９Ａへ指令電流として出力すると共に、演算した目標旋回駆動圧よりも所定値、例えば１ＭＰａだけ低い値を演算結果として目標吐出量演算部３０へ出力するようにしている。所定値を用いた理由は後述する。なお、この演算結果が負の値になったときには、リミッタ処理部２６Ａ２は０ＭＰａとみなして目標吐出量演算部３０へ出力するようにしている。 On the other hand, the limiter processing unit 26A2 determines the swing drive pressure calculated by the PID control unit 26A1 if the swing drive pressure calculated by the PID control unit 26A1 is equal to or lower than the upper limit pressure of the swing drive pressure set by the pressure limiting unit 25A2. Is calculated to be a target turning drive pressure. Note that the maximum value PRmax of the upper limit pressure of the turning drive pressure described above is set to be larger than the turning drive pressure calculated by the PID control unit 26A1. The limiter processing unit 26A2 outputs the calculated target turning drive pressure as a command current to the inflow control unit 19A, and calculates a target discharge amount as a calculation result that is a predetermined value, for example, 1 MPa lower than the calculated target turning drive pressure. The data is output to the calculation unit 30. The reason for using the predetermined value will be described later. When this calculation result becomes a negative value, the limiter processing unit 26A2 regards it as 0 MPa and outputs it to the target discharge amount calculation unit 30.
　同様に、本発明の第１実施形態は、右操作レバー１５Ｂによって操作される操作量と目標速度演算部２５Ｂ１によって演算される目標ブーム速度との関係として、例えば図５に示す目標速度テーブル２５ｂ１を予め記憶した記憶部２５ｂ３とを備え、この記憶部２５ｂ３は、例えば目標速度演算部２５Ｂ１の内部に格納されている。 Similarly, in the first embodiment of the present invention, for example, a target speed table 25b1 shown in FIG. 5 is used as the relationship between the operation amount operated by the right operation lever 15B and the target boom speed calculated by the target speed calculation unit 25B1. The storage unit 25b3 is stored in advance, and the storage unit 25b3 is stored in, for example, the target speed calculation unit 25B1.
　この目標速度演算部２５Ｂ１の目標速度テーブル２５ｂ１は、操作量ＸＲが大きくなるに従って目標ブーム速度ＶＢが増加する関数関係を有し、この関数関係は、ブーム４Ａの回動動作に対してブーム４Ａの上げやブーム４Ａの下げ等の動作方向によって要求される性能が異なるので、右操作レバー１５Ｂの操作方向や操作量に応じて設定される。本発明の第１実施形態では、説明を分かり易くするために上述した目標速度テーブル２５ａ１の関数関係と同様に、目標速度テーブル２５ｂ１の関数関係が原点（ＸＲ＝０，ＶＢ＝０）を中心とする点対象に設定されている。なお、目標速度テーブル２５ｂ１における目標ブーム速度ＶＢが負の値のときの速度は、目標ブーム速度ＶＢが正の値のときの速度に対して逆方向であることを示している。 The target speed table 25b1 of the target speed calculation unit 25B1 has a functional relationship in which the target boom speed VB increases as the operation amount XR increases, and this functional relationship indicates that the boom 4A is rotated with respect to the turning operation of the boom 4A. Since the required performance differs depending on the operation direction such as raising and lowering the boom 4A, it is set according to the operation direction and the operation amount of the right operation lever 15B. In the first embodiment of the present invention, the functional relationship of the target speed table 25b1 is centered on the origin (XR = 0, VB = 0), similar to the functional relationship of the target speed table 25a1 described above for easy understanding. It is set as a point target. It should be noted that the speed when the target boom speed VB is a negative value in the target speed table 25b1 indicates that the speed is opposite to the speed when the target boom speed VB is a positive value.
　また、目標速度テーブル２５ｂ１は、最小値ＶＢｍｉｎ及び最大値ＶＢｍａｘを有し、操作量ＸＲの絶対値が大きくなるに従って操作量ＸＲに対する目標ブーム速度ＶＢの傾きの絶対値が段階的に増加するようになっている。目標速度演算部２５Ｂ１は、このように設定された目標速度テーブル２５ｂ１の関数関係に対し、操作量センサ１５Ｂ１によって検出された操作量を適用して目標ブーム速度を演算するようにしている。 The target speed table 25b1 has a minimum value VBmin and a maximum value VBmax so that the absolute value of the gradient of the target boom speed VB with respect to the operation amount XR increases stepwise as the absolute value of the operation amount XR increases. It has become. The target speed calculation unit 25B1 calculates the target boom speed by applying the operation amount detected by the operation amount sensor 15B1 to the functional relationship of the target speed table 25b1 set in this way.
　本発明の第１実施形態は、右操作レバー１５Ｂによって操作される操作量と圧力制限部２５Ｂ２によって設定されるブーム駆動圧の上限圧力との関係として、例えば図５に示す上限圧力テーブル２５ｂ２を予め記憶した記憶部２５ｂ４を備え、この記憶部２５ｂ４は、例えば圧力制限部２５Ｂ２の内部に格納されている。 In the first embodiment of the present invention, for example, an upper limit pressure table 25b2 shown in FIG. 5 is previously stored as the relationship between the operation amount operated by the right operation lever 15B and the upper limit pressure of the boom drive pressure set by the pressure limiting unit 25B2. The storage unit 25b4 is stored, and the storage unit 25b4 is stored, for example, inside the pressure limiting unit 25B2.
　圧力制限部２５Ｂ２の上限圧力テーブル２５ｂ２は、操作量ＸＲの絶対値が大きくなるに従ってブーム駆動圧の上限圧力ＰＢが増加する関数関係を有し、この関数関係は、上述したようにブーム４Ａの回動動作に対してブーム４Ａの上げやブーム４Ａの下げ等の動作方向によって要求される性能が異なるので、右操作レバー１５Ｂの操作方向や操作量に応じて設定される。本発明の第１実施形態では、説明を分かり易くするために上述した上限圧力テーブル２５ａ２の関数関係と同様に、上限圧力テーブル２５ｂ２はブーム駆動圧の上限圧力ＰＢ軸（ＸＲ＝０）に対して線対象に設定されている。 The upper limit pressure table 25b2 of the pressure limiting unit 25B2 has a functional relationship in which the upper limit pressure PB of the boom driving pressure increases as the absolute value of the operation amount XR increases. This functional relationship is the rotation of the boom 4A as described above. Since the required performance differs depending on the operation direction such as raising the boom 4A and lowering the boom 4A with respect to the moving operation, the setting is set according to the operation direction and the operation amount of the right operation lever 15B. In the first embodiment of the present invention, the upper limit pressure table 25b2 is relative to the upper limit pressure PB axis (XR = 0) of the boom drive pressure, as in the functional relationship of the upper limit pressure table 25a2 described above for easy understanding. The line target is set.
　上限圧力テーブル２５ｂ２の関数関係は、最小値ＰＢｍｉｎ（＞０）と最大値ＰＢｍａｘを有し、操作量ＸＲの絶対値が大きくなるに従って操作量ＸＲに対するブーム駆動圧の上限圧力ＰＢの傾きが段階的に増加するように設定されている。圧力制限部２５Ｂ２は、このように設定された上限圧力テーブル２５ｂ２の関数関係に対し、操作量センサ１５Ｂ１によって検出された操作量を適用してブーム駆動圧の上限圧力を設定するようにしている。 The functional relationship of the upper limit pressure table 25b2 has a minimum value PBmin (> 0) and a maximum value PBmax, and the gradient of the upper limit pressure PB of the boom drive pressure with respect to the operation amount XR is stepped as the absolute value of the operation amount XR increases. Is set to increase. The pressure limiting unit 25B2 sets the upper limit pressure of the boom driving pressure by applying the operation amount detected by the operation amount sensor 15B1 to the functional relationship of the upper limit pressure table 25b2 set in this way.
　目標駆動圧演算部２６Ｂは、速度センサ１８Ｂによって検出されたブームシリンダ４ａの速度と目標速度演算部２５Ｂ１によって演算された目標ブーム速度との偏差に基づいて、比例制御、微分制御、及び積分制御を組み合わせたＰＩＤ制御を行うＰＩＤ制御部２６Ｂ１と、このＰＩＤ制御部２６Ｂ１及び圧力制限部２５Ｂ２に接続され、ＰＩＤ制御部２６Ｂ１の出力値に対して圧力制限部２５Ｂ２によって設定されたブーム駆動圧の上限圧力の制限を加えるリミッタ処理を施すリミッタ処理部２６Ｂ２とを有している。 The target drive pressure calculator 26B performs proportional control, differential control, and integral control based on the deviation between the speed of the boom cylinder 4a detected by the speed sensor 18B and the target boom speed calculated by the target speed calculator 25B1. A PID control unit 26B1 that performs combined PID control, and an upper limit pressure of the boom drive pressure that is connected to the PID control unit 26B1 and the pressure limiting unit 25B2 and set by the pressure limiting unit 25B2 with respect to the output value of the PID control unit 26B1 And a limiter processing unit 26B2 for performing a limiter process for adding the above limitation.
　ＰＩＤ制御部２６Ｂ１は、速度センサ１８Ｂによって検出されたブームシリンダ４ａの速度と目標速度演算部２５Ｂ１によって演算された目標ブーム速度に対してＰＩＤ制御を行うことにより、速度偏差を解消する、すなわちブームシリンダ４ａの速度を目標ブーム速度に一致させるのに必要とされるブーム駆動圧を演算してリミッタ処理部２６Ｂ２へ出力するようにしている。なお、ＰＩＤ制御部２６Ｂ１はＰＩＤ制御を用いているが、目標値に対して出力値を追従させることができる制御方式であれば良く、ＰＩＤに拘るものではない。 The PID control unit 26B1 eliminates the speed deviation by performing PID control on the speed of the boom cylinder 4a detected by the speed sensor 18B and the target boom speed calculated by the target speed calculation unit 25B1, that is, the boom cylinder The boom driving pressure required to match the speed 4a with the target boom speed is calculated and output to the limiter processing unit 26B2. The PID control unit 26B1 uses PID control, but any control method can be used as long as the output value can follow the target value, and the PID control unit 26B1 is not limited to PID.
　リミッタ処理部２６Ｂ２は、ＰＩＤ制御部２６Ｂ１によって演算されたブーム駆動圧と圧力制限部２５Ｂ２によって設定されたブーム駆動圧の上限圧力とを比較し、ＰＩＤ制御部２６Ｂ１によ
って演算されたブーム駆動圧が圧力制限部２５Ｂ２によって設定されたブーム駆動圧の上限圧力よりも大きければ、圧力制限部２５Ｂ２によって設定されたブーム駆動圧の上限圧力を目標ブーム駆動圧とする演算を行うようにしている。 The limiter processing unit 26B2 compares the boom driving pressure calculated by the PID control unit 26B1 with the upper limit pressure of the boom driving pressure set by the pressure limiting unit 25B2, and the boom driving pressure calculated by the PID control unit 26B1 is the pressure. If the upper limit pressure of the boom drive pressure set by the limiter 25B2 is greater than the upper limit pressure of the boom drive pressure, the calculation is performed with the upper limit pressure of the boom drive pressure set by the pressure limiter 25B2 as the target boom drive pressure.
　一方、リミッタ処理部２６Ｂ２は、ＰＩＤ制御部２６Ｂ１によって演算されたブーム駆動圧が圧力制限部２５Ｂ２によって設定されたブーム駆動圧の上限圧力以下であれば、ＰＩＤ制御部２６Ｂ１によって演算されたブーム駆動圧を-目標ブーム駆動圧とする演算を行うようにしている。さらに、リミッタ処理部２６Ｂ２は、演算した目標ブーム駆動圧を流入制御部１９Ｂへ指令電流として出力すると共に、演算した目標ブーム駆動圧よりも所定値、例えば１ＭＰａだけ低い値を演算結果として目標吐出量演算部３０へ出力するようにしている。なお、この演算結果が負の値になったときには、リミッタ処理部２６Ｂ２は０ＭＰａとみなして目標吐出量演算部３０へ出力するようにしている。 On the other hand, if the boom driving pressure calculated by the PID control unit 26B1 is equal to or less than the upper limit pressure of the boom driving pressure set by the pressure limiting unit 25B2, the limiter processing unit 26B2 may calculate the boom driving pressure calculated by the PID control unit 26B1. -Calculates the target boom drive pressure. Further, the limiter processing unit 26B2 outputs the calculated target boom driving pressure as a command current to the inflow control unit 19B, and calculates a target discharge amount as a calculation result that is a predetermined value, for example, 1 MPa lower than the calculated target boom driving pressure. The data is output to the calculation unit 30. When the calculation result becomes a negative value, the limiter processing unit 26B2 regards it as 0 MPa and outputs it to the target discharge amount calculation unit 30.
　目標吐出量演算部３０は、例えばリミッタ処理部２６Ａ２から入力した入力値とリミッタ処理部２６Ｂ２から入力した入力値に基づいて、油圧ポンプ１２の吐出圧の目標値（以下、便宜的に目標吐出圧と呼ぶ）を演算する目標吐出圧演算部を有している。この目標吐出圧演算部は、例えばリミッタ処理部２６Ａ２から入力した入力値とリミッタ処理部２６Ｂ２から入力した入力値のうち大きい方を選択して油圧ポンプ１２の目標吐出圧とする最大目標吐出圧選択部３０Ａから成っている。 For example, the target discharge amount calculation unit 30 is based on an input value input from the limiter processing unit 26A2 and an input value input from the limiter processing unit 26B2. A target discharge pressure calculation unit. This target discharge pressure calculation unit selects the maximum target discharge pressure as the target discharge pressure of the hydraulic pump 12 by selecting the larger one of the input value input from the limiter processing unit 26A2 and the input value input from the limiter processing unit 26B2, for example. It consists of part 30A.
　目標吐出量演算部３０は、例えば上述したＰＩＤ制御部２６Ａ１，２６Ｂ１と同様に、吐出圧センサ１７によって検出された油圧ポンプ１２の吐出圧と最大目標吐出圧選択部３０Ａによって選択された油圧ポンプ１２の目標吐出圧との偏差に基づいてＰＩＤ制御を行うＰＩＤ制御部３０Ｂと、このＰＩＤ制御部３０Ｂの出力値に対してエンジン１１の回転数で補正する目標吐出量補正部３０Ｃとを有している。 The target discharge amount calculation unit 30 is, for example, similar to the PID control units 26A1 and 26B1 described above, the discharge pressure of the hydraulic pump 12 detected by the discharge pressure sensor 17 and the hydraulic pump 12 selected by the maximum target discharge pressure selection unit 30A. A PID control unit 30B that performs PID control based on a deviation from the target discharge pressure, and a target discharge amount correction unit 30C that corrects the output value of the PID control unit 30B with the rotational speed of the engine 11. Yes.
　ＰＩＤ制御部３０Ｂは、吐出圧センサ１７によって検出された油圧ポンプ１２の吐出圧と最大目標吐出圧選択部３０Ａによって演算された油圧ポンプ１２の目標吐出圧に対してＰＩＤ制御を行うことにより、油圧ポンプ１２の吐出圧を目標吐出圧に一致させるのに必要とされる吐出量を演算して目標吐出量補正部３０Ｃへ出力するようにしている。目標吐出量補正部３０Ｃは、ＰＩＤ制御部３０Ｂから入力した吐出量に対してエンジン回転数検出部１１Ａによって検出されたエンジン１１の回転数で除算して目標吐出量とする演算を行い、演算した目標吐出量を傾転量調整部１２Ａへ出力するようにしている。 The PID control unit 30B performs hydraulic pressure control by performing PID control on the discharge pressure of the hydraulic pump 12 detected by the discharge pressure sensor 17 and the target discharge pressure of the hydraulic pump 12 calculated by the maximum target discharge pressure selection unit 30A. The discharge amount required to make the discharge pressure of the pump 12 coincide with the target discharge pressure is calculated and output to the target discharge amount correction unit 30C. The target discharge amount correction unit 30C calculates the target discharge amount by dividing the discharge amount input from the PID control unit 30B by the rotation number of the engine 11 detected by the engine rotation number detection unit 11A. The target discharge amount is output to the tilt amount adjustment unit 12A.
　各流入制御部１９Ａ，１９Ｂは、例えば油圧ポンプ１２と、旋回モータ３ａ及びブームシリンダ４ａとの間に設けられ、図６（ａ）に示すように通過する作動油の圧力を制御する圧力制御弁としての電磁比例減圧弁１９Ａ１，１９Ｂ１を含んでいる。各電磁比例減圧弁１９Ａ１，１９Ｂ１は、外部のリミッタ処理部２６Ａ２，２６Ｂ２から入力した目標旋回駆動圧及び目標ブーム駆動圧に対する指令電流を受けて駆動し、指令電流が増加するに従って開口量を減少させるようにしている。 Each inflow control unit 19A, 19B is provided between, for example, the hydraulic pump 12, the turning motor 3a, and the boom cylinder 4a, and is a pressure control valve that controls the pressure of hydraulic fluid that passes as shown in FIG. 6 (a). As electromagnetic proportional pressure reducing valves 19A1 and 19B1. Each of the electromagnetic proportional pressure reducing valves 19A1, 19B1 is driven by receiving a command current for the target turning driving pressure and the target boom driving pressure input from the external limiter processing units 26A2, 26B2, and decreases the opening amount as the command current increases. I am doing so.
　具体的には、各流入制御部１９Ａ，１９Ｂの電磁比例減圧弁１９Ａ１，１９Ｂ１は、例えば１次側（油圧ポンプ１２側）と２次側（旋回モータ３ａ，ブームシリンダ４ａ側）を連通する方向へ本体を付勢するばね１９ａ１，１９ｂ１と、ばね１９ａ１，１９ｂ１に対抗する方向に力を発生させる電磁ソレノイド１９ａ２，１９ｂ２とを有している。各電磁比例減圧弁１９Ａ１，１９Ｂ１は、図６（ｂ）に示すように電磁ソレノイド１９ａ２，１９ｂ２への指令電流Ｉの大きさが所定の電流値ＩＡ未満のとき、２次側（旋回モータ３ａ，ブームシリンダ４ａ側）の設定圧ＰＳが最大値ＰＳｍａｘとなり、指令電流Ｉの大きさが所定の電流値ＩＡ以上のとき、２次側（旋回モータ３ａ側、ブームシリンダ４ａ側）の設定圧ＰＳが指令電流Ｉの大きさに対して反比例し、指令電流Ｉの大きさが最大値Ｉｍａｘのとき、２次側（旋回モータ３ａ側、ブームシリンダ４ａ側）の設定圧ＰＳが０Ａになるように開口量を調整している。 Specifically, the electromagnetic proportional pressure reducing valves 19A1 and 19B1 of the inflow control units 19A and 19B are, for example, directions in which the primary side (hydraulic pump 12 side) and the secondary side (swing motor 3a and boom cylinder 4a side) communicate with each other. Springs 19a1 and 19b1 for urging the main body and electromagnetic solenoids 19a2 and 19b2 for generating a force in a direction opposite to the springs 19a1 and 19b1. As shown in FIG. 6 (b), the electromagnetic proportional pressure reducing valves 19A1 and 19B1 are arranged on the secondary side (swing motor 3a, 19b2) when the magnitude of the command current I to the electromagnetic solenoids 19a2 and 19b2 is less than a predetermined current value IA. When the set pressure PS on the boom cylinder 4a side is the maximum value PSmax and the magnitude of the command current I is equal to or greater than the predetermined current value IA, the set pressure PS on the secondary side (the swing motor 3a side and the boom cylinder 4a side) is When the magnitude of the command current I is the maximum value Imax, the opening is set so that the set pressure PS on the secondary side (the swing motor 3a side and the boom cylinder 4a side) becomes 0A. The amount is adjusted.
　すなわち、各電磁比例減圧弁１９Ａ１，１９Ｂ１は、例えば指令電流Ｉの大きさが所定の電流値ＩＡ未満のとき、ばね１９ａ１，１９ｂ１の弾性力によって１次側（油圧ポンプ１２側）と２次側（旋回モータ３ａ，ブームシリンダ４ａ側）を連通する切換位置（図６（ａ）に示すＤ位置）に保ち、指令電流Ｉの大きさが所定の電流値ＩＡ以上のとき、ばね１９ａ１，１９ｂ１の弾性力に抗して本体が移動し、作動油タンク１３を連通する切換位置（図６（ａ）に示すＥ位置）へ切り替えるようにしている。 That is, when the magnitude of the command current I is less than a predetermined current value IA, for example, the electromagnetic proportional pressure reducing valves 19A1 and 19B1 are arranged on the primary side (hydraulic pump 12 side) and the secondary side by the elastic force of the springs 19a1 and 19b1. When the command current I is greater than or equal to a predetermined current value IA while keeping the switching position (the D position shown in FIG. 6A) in which the (turning motor 3a, boom cylinder 4a side) communicates, the springs 19a1 and 19b1 The main body moves against the elastic force, and is switched to a switching position (E position shown in FIG. 6A) where the hydraulic oil tank 13 communicates.
　また、各電磁比例減圧弁１９Ａ１，１９Ｂ１は、２次側（旋回モータ３ａ，ブームシリンダ４ａ側）の作動油をばね１９ａ１，１９ｂ１の弾性力に抗して作用させることにより、２次側（旋回モータ３ａ，ブームシリンダ４ａ側）の作動油が過剰となった場合に、作動油を作動油タンク１３へ流出させるようにしている。傾転量制御部１２Ａは、目標吐出量補正部３０Ｃから目標吐出量を入力し、目標吐出量に応じて油圧ポンプ１２の傾転量を調整することにより、油圧ポンプ１２の吐出量を目標吐出量補正部３０Ｃで補正された目標吐出量に制御している。 Each of the electromagnetic proportional pressure reducing valves 19A1 and 19B1 causes the secondary side (swing motor 3a, boom cylinder 4a side) hydraulic oil to act against the elastic force of the springs 19a1 and 19b1, thereby rotating the secondary side (swinging). When the hydraulic oil in the motor 3a and boom cylinder 4a side) becomes excessive, the hydraulic oil is allowed to flow out to the hydraulic oil tank 13. The tilt amount control unit 12A receives the target discharge amount from the target discharge amount correction unit 30C, and adjusts the tilt amount of the hydraulic pump 12 according to the target discharge amount, thereby adjusting the discharge amount of the hydraulic pump 12 to the target discharge. The target discharge amount corrected by the amount correction unit 30C is controlled.
　次に、本発明の第１実施形態に係るコントローラ２０による制御動作について説明し、特に油圧ショベル１の単独動作として旋回体３の旋回動作のみを行う場合、複合動作として旋回体３の旋回動作及びブーム４Ａの回動動作を行う場合を順に説明する。最初に、単独動作のうち左操作レバー１５Ａのフルレバー操作が行われるときのコントローラ２０の制御動作を示す。 Next, the control operation by the controller 20 according to the first embodiment of the present invention will be described, and in particular, when only the turning motion of the swing body 3 is performed as a single operation of the hydraulic excavator 1, the swing operation of the swing body 3 as a combined operation and The case where the boom 4A is rotated will be described in order. First, the control operation of the controller 20 when the full lever operation of the left operation lever 15A is performed in the single operation will be described.
　キャブ７内の運転シートに着座した操作者は、左操作レバー１５Ａを左方向又は右方向へフルレバー操作することにより、パイロットポンプから吐出されたパイロット圧油のパイロット圧が最大となり、このパイロット圧が旋回モータ３ａ側の方向制御弁１６Ａに作用するので、方向制御弁１６Ａの切換位置が中立位置（図２に示すＢ位置）から左位置（図２に示すＡ位置）又は右位置（図２に示すＣ位置）に切り替えられ、方向制御弁１６Ａの開口量が最大となる。 The operator seated on the driving seat in the cab 7 operates the left operating lever 15A to the left or right to make the pilot pressure of the pilot pressure oil discharged from the pilot pump maximum, and this pilot pressure is reduced. Since it acts on the direction control valve 16A on the swing motor 3a side, the switching position of the direction control valve 16A is changed from the neutral position (position B shown in FIG. 2) to the left position (position A shown in FIG. 2) or the right position (FIG. 2). (C position shown), and the opening amount of the direction control valve 16A is maximized.
　このとき、操作量センサ１５Ａ１は左操作レバー１５Ａの操作量ＸＬとして最大値ＸＬｍａｘを検出し（ＸＬ＝ＸＬｍａｘ）、検出信号をコントローラ２０へ出力する。また、速度センサ１８Ａは旋回モータ３ａの速度を検出し、検出信号をコントローラ２０へ出力する。さらに、吐出圧センサ１７は油圧ポンプ１２の吐出圧を検出し、検出信号をコントローラ２０へ出力する。 At this time, the operation amount sensor 15A1 detects the maximum value XLmax as the operation amount XL of the left operation lever 15A (XL = XLmax), and outputs a detection signal to the controller 20. The speed sensor 18 </ b> A detects the speed of the turning motor 3 a and outputs a detection signal to the controller 20. Further, the discharge pressure sensor 17 detects the discharge pressure of the hydraulic pump 12 and outputs a detection signal to the controller 20.
　コントローラ２０は操作量センサ１５Ａ１から検出信号を入力すると、コントローラ２０の目標速度演算部２５Ａ１が、目標速度テーブル２５ａ１の関数関係に対し、操作量センサ１５Ａ１で検出された操作量ＸＬｍａｘを適用することにより、目標旋回速度ＶＲとして最大値ＶＲｍａｘを求め（ＶＲ＝ＶＲｍａｘ）、この演算結果を目標駆動圧演算部２６Ａへ出力する。また、コントローラ２０の圧力制限部２５Ａ２は、上限圧力テーブル２５ａ２の関数関係に対し、操作量センサ１５Ａ１で検出された操作量ＸＬｍａｘを適用することにより、旋回駆動圧の上限圧力ＰＲを最大値ＰＲｍａｘに設定し（ＰＲ＝ＰＲｍａｘ）、この設定結果をコントローラ２０の目標駆動圧演算部２６Ａへ出力する。なお、旋回速度の単位は、通常ｒｐｍ等で表記されるが、ここでは省略する。 When the controller 20 inputs a detection signal from the operation amount sensor 15A1, the target speed calculation unit 25A1 of the controller 20 applies the operation amount XLmax detected by the operation amount sensor 15A1 to the functional relationship of the target speed table 25a1. Then, the maximum value VRmax is obtained as the target turning speed VR (VR = VRmax), and the calculation result is output to the target drive pressure calculation unit 26A. Further, the pressure limiting unit 25A2 of the controller 20 applies the operation amount XLmax detected by the operation amount sensor 15A1 to the functional relationship of the upper limit pressure table 25a2, thereby setting the upper limit pressure PR of the turning drive pressure to the maximum value PRmax. It is set (PR = PRmax), and this setting result is output to the target drive pressure calculation unit 26A of the controller 20. In addition, although the unit of turning speed is normally described by rpm etc., it abbreviate | omits here.
　目標駆動圧演算部２６Ａは、速度センサ１８Ａから検出信号、目標速度演算部２５Ａ１から演算結果、及び圧力制限部２５Ａ２から設定結果を入力すると、目標駆動圧演算部２６ＡのＰＩＤ制御部２６Ａ１が、速度センサ１８Ａで検出された旋回モータ３ａの速度と目標速度演算部２５Ａ１で演算された目標旋回速度ＶＲｍａｘに対してＰＩＤ制御を行うことにより、旋回モータ３ａの速度を目標旋回速度ＶＲｍａｘに一致させるのに必要とされる旋回駆動圧Ｐｘを求め、この演算結果を目標駆動圧演算部２６Ａのリミッタ処理部２６Ａ２へ出力する。 When the target drive pressure calculator 26A receives the detection signal from the speed sensor 18A, the calculation result from the target speed calculator 25A1, and the setting result from the pressure limiter 25A2, the PID controller 26A1 of the target drive pressure calculator 26A PID control is performed on the speed of the turning motor 3a detected by the sensor 18A and the target turning speed VRmax calculated by the target speed calculation unit 25A1, thereby matching the speed of the turning motor 3a with the target turning speed VRmax. The required turning drive pressure Px is obtained, and the calculation result is output to the limiter processing unit 26A2 of the target drive pressure calculation unit 26A.
　リミッタ処理部２６Ａ２は、ＰＩＤ制御部２６Ａ１から演算結果を入力すると、ＰＩＤ制御部２６Ａ１で演算された旋回駆動圧Ｐｘと圧力制限部２５Ａ２で設定された旋回駆動圧の上限圧力ＰＲｍａｘを比較する。このとき、上述したように圧力制限部２５Ａ２で設定された旋回駆動圧の上限圧力ＰＲｍａｘは最大値であるので、ＰＩＤ制御部２６Ａ１で演算された旋回駆動圧Ｐｘは、圧力制限部２５Ａ２で設定された旋回駆動圧の上限圧力ＰＲｍａｘ以下であり、圧力制限部２５Ａ２による制限を受けない。 When the calculation result is input from the PID control unit 26A1, the limiter processing unit 26A2 compares the swing drive pressure Px calculated by the PID control unit 26A1 with the upper limit pressure PRmax of the swing drive pressure set by the pressure limiting unit 25A2. At this time, as described above, since the upper limit pressure PRmax of the turning drive pressure set by the pressure limiting unit 25A2 is the maximum value, the turning drive pressure Px calculated by the PID control unit 26A1 is set by the pressure limiting unit 25A2. The upper limit pressure PRmax of the turning drive pressure is not more than the upper limit pressure PRmax and is not restricted by the pressure restriction unit 25A2.
　従って、リミッタ処理部２６Ａ２はＰＩＤ制御部２６Ａ１で演算された旋回駆動圧Ｐｘをそのまま目標旋回駆動圧として求める。そして、リミッタ処理部２６Ａ２は、指令電流Ｉとして目標旋回駆動圧Ｐｘに対応するＩｘを流入制御部１９Ａへ出力すると共に（０≦Ｉ＝Ｉｘ＜Ｉｍａｘ）、目標旋回駆動圧Ｐｘから所定値１ＭＰａを引算した演算結果をコントローラ２０の目標吐出量演算部３０へ出力する。 Therefore, the limiter processing unit 26A2 obtains the turning drive pressure Px calculated by the PID control unit 26A1 as it is as the target turning drive pressure. The limiter processing unit 26A2 outputs Ix corresponding to the target turning drive pressure Px as the command current I to the inflow control unit 19A (0 ≦ I = Ix <Imax), and generates a predetermined value 1 MPa from the target turning drive pressure Px. The subtracted calculation result is output to the target discharge amount calculation unit 30 of the controller 20.
　一方、操作者は右操作レバー１５Ｂを操作していないので、パイロットポンプから右操作レバー１５Ｂへ導かれたパイロット圧油は減圧されてパイロット圧が０ＭＰａとなり、方向制御弁１６Ｂの切換位置が中立位置（図２に示すＢ位置）を維持する。このとき、操作量センサ１５Ｂ１は右操作レバー１５Ｂの操作量ＸＲとして０の値を検出し（ＸＲ＝０）、検出信号をコントローラ２０へ出力する。また、速度センサ１８Ｂはブームシリンダ４ａの速度を検出し、検出信号をコントローラ２０へ出力する。さらに、吐出圧センサ１７は油圧ポンプ１２の吐出圧を検出し、検出信号をコントローラ２０へ出力する。 On the other hand, since the operator does not operate the right operation lever 15B, the pilot pressure oil introduced from the pilot pump to the right operation lever 15B is reduced to a pilot pressure of 0 MPa, and the switching position of the direction control valve 16B is set to the neutral position. (B position shown in FIG. 2) is maintained. At this time, the operation amount sensor 15B1 detects a value of 0 as the operation amount XR of the right operation lever 15B (XR = 0), and outputs a detection signal to the controller 20. Further, the speed sensor 18B detects the speed of the boom cylinder 4a and outputs a detection signal to the controller 20. Further, the discharge pressure sensor 17 detects the discharge pressure of the hydraulic pump 12 and outputs a detection signal to the controller 20.
　コントローラ２０は操作量センサ１５Ｂ１から検出信号を入力すると、コントローラ２０の目標速度演算部２５Ｂ１が、目標速度テーブル２５ｂ１の関数関係に対し、操作量センサ１５Ｂ１で検出された操作量ＸＲ（＝０）を適用することにより、目標ブーム速度ＶＢ＝０を求め、この演算結果をコントローラ２０の目標駆動圧演算部２６Ｂへ出力する。また、コントローラ２０の圧力制限部２５Ｂ２は、上限圧力テーブル２５ｂ２の関数関係に対し、操作量センサ１５Ｂ１で検出された操作量ＸＲ（＝０）を適用することにより、ブーム駆動圧の上限圧力ＰＢを最小値ＰＢｍｉｎに設定し（ＰＢ＝ＰＢｍｉｎ）、この設定結果を目標駆動圧演算部２６Ｂへ出力する。なお、ブーム速度の単位は、通常ｍ／ｓ等で表記されるが、ここでは省略する。 When the controller 20 inputs a detection signal from the operation amount sensor 15B1, the target speed calculation unit 25B1 of the controller 20 uses the operation amount XR (= 0) detected by the operation amount sensor 15B1 with respect to the functional relationship of the target speed table 25b1. By applying, the target boom speed VB = 0 is obtained, and the calculation result is output to the target drive pressure calculation unit 26B of the controller 20. Further, the pressure limiting unit 25B2 of the controller 20 applies the operation amount XR (= 0) detected by the operation amount sensor 15B1 to the functional relationship of the upper limit pressure table 25b2, so that the upper limit pressure PB of the boom driving pressure is obtained. The minimum value PBmin is set (PB = PBmin), and the setting result is output to the target drive pressure calculation unit 26B. In addition, although the unit of boom speed is normally described by m / s etc., it abbreviate | omits here.
　目標駆動圧演算部２６Ｂは、速度センサ１８Ｂから検出信号、目標速度演算部２５Ｂ１から演算結果、及び圧力制限部２５Ｂ２から設定結果を入力すると、目標駆動圧演算部２６ＢのＰＩＤ制御部２６Ｂ１が、速度センサ１８Ｂで検出されたブームシリンダ４ａの速度と目標速度演算部２５Ｂ１で演算された目標ブーム速度ＶＢ＝０に対してＰＩＤ制御を行うことにより、ブームシリンダ４ａの速度を目標ブーム速度ＶＢ＝０に一致させるのに必要とされるブーム駆動圧として０ＭＰａを求め、この演算結果を目標駆動圧演算部２６Ｂのリミッタ処理部２６Ｂ２へ出力する。 When the target drive pressure calculation unit 26B receives the detection signal from the speed sensor 18B, the calculation result from the target speed calculation unit 25B1, and the setting result from the pressure limiting unit 25B2, the PID control unit 26B1 of the target drive pressure calculation unit 26B By performing PID control on the speed of the boom cylinder 4a detected by the sensor 18B and the target boom speed VB = 0 calculated by the target speed calculation unit 25B1, the speed of the boom cylinder 4a is set to the target boom speed VB = 0. 0 MPa is obtained as the boom driving pressure required for matching, and the calculation result is output to the limiter processing unit 26B2 of the target driving pressure calculation unit 26B.
　リミッタ処理部２６Ｂ２は、ＰＩＤ制御部２６Ｂ１から演算結果を入力すると、ＰＩＤ制御部２６Ｂ１で演算されたブーム駆動圧（０ＭＰａ）と圧力制限部２５Ｂ２で設定されたブーム駆動圧の上限圧力ＰＢｍｉｎを比較する。このとき、上述したようにＰＩＤ制御部２６Ｂ１で演算されたブーム駆動圧は０ＭＰａであり、圧力制限部２５Ｂ２で設定されたブーム駆動圧の上限圧力ＰＢｍｉｎは最小値で０ＭＰａより大きいので、リミッタ処理部２６Ｂ２はＰＩＤ制御部２６Ｂ１で演算されたブーム駆動圧（０ＭＰａ）を目標ブーム駆動圧として求める。 When the limiter processing unit 26B2 inputs the calculation result from the PID control unit 26B1, the limiter processing unit 26B2 compares the boom driving pressure (0 MPa) calculated by the PID control unit 26B1 with the upper limit pressure PBmin of the boom driving pressure set by the pressure limiting unit 25B2. . At this time, as described above, the boom driving pressure calculated by the PID control unit 26B1 is 0 MPa, and the upper limit pressure PBmin of the boom driving pressure set by the pressure limiting unit 25B2 is the minimum value and larger than 0 MPa. 26B2 calculates | requires the boom drive pressure (0 Mpa) calculated by PID control part 26B1 as a target boom drive pressure.
　そして、リミッタ処理部２６Ｂ２は、指令電流Ｉとして目標ブーム駆動圧（０ＭＰａ）に対応する最大値Ｉｍａｘを流入制御部１９Ｂへ出力すると共に、目標ブーム駆動圧（０ＭＰａ）から所定値１ＭＰａを引算した演算結果を目標吐出量演算部３０へ出力する。なお、このとき出力される演算結果は負の値になるので、０ＭＰａが出力される。 The limiter processing unit 26B2 outputs the maximum value Imax corresponding to the target boom drive pressure (0 MPa) as the command current I to the inflow control unit 19B, and subtracts the predetermined value 1 MPa from the target boom drive pressure (0 MPa). The calculation result is output to the target discharge amount calculation unit 30. Since the calculation result output at this time is a negative value, 0 MPa is output.
　次に、目標吐出量演算部３０の最大目標吐出圧選択部３０Ａは、リミッタ処理部２６Ａ２，２６Ｂ２から演算結果を入力すると、リミッタ処理部２６Ａ２から入力した入力値（（Ｐｘ－１）ＭＰａ）とリミッタ処理部２６Ｂ２から入力した入力値（０ＭＰａ）を比較する。このとき、上述したようにリミッタ処理部２６Ａ２から入力した入力値は、ＰＩＤ制御部２６Ａ１で演算された旋回駆動圧Ｐｘから１ＭＰａを引算した値（（Ｐｘ－１）ＭＰａ）であり、０ＭＰａ以上となるので、リミッタ処理部２６Ｂ２から入力した入力値（０ＭＰａ）よりも大きい。従って、最大目標吐出圧選択部３０Ａは、リミッタ処理部２６Ａ２から入力した入力値（（Ｐｘ－１）ＭＰａ）を選択して油圧ポンプ１２の目標吐出圧として求め、演算結果を目標吐出量演算部３０のＰＩＤ制御部３０Ｂへ出力する。 Next, when the maximum target discharge pressure selection unit 30A of the target discharge amount calculation unit 30 inputs the calculation results from the limiter processing units 26A2 and 26B2, the input value ((Px-1) MPa) input from the limiter processing unit 26A2 and The input value (0 MPa) input from the limiter processing unit 26B2 is compared. At this time, as described above, the input value input from the limiter processing unit 26A2 is a value obtained by subtracting 1 MPa from the turning drive pressure Px calculated by the PID control unit 26A1 ((Px−1) MPa), and is 0 MPa or more. Therefore, it is larger than the input value (0 MPa) input from the limiter processing unit 26B2. Therefore, the maximum target discharge pressure selection unit 30A selects the input value ((Px-1) MPa) input from the limiter processing unit 26A2 and obtains it as the target discharge pressure of the hydraulic pump 12, and the calculation result is the target discharge amount calculation unit. It outputs to 30 PID control part 30B.
　ＰＩＤ制御部３０Ｂは、最大目標吐出圧選択部３０Ａから演算結果を入力すると、吐出圧センサ１７で検出された油圧ポンプ１２の吐出圧と最大目標吐出圧選択部３０Ａで演算された油圧ポンプ１２の目標吐出圧（（Ｐｘ－１）ＭＰａ）に対してＰＩＤ制御を行うことにより、油圧ポンプ１２の吐出圧を目標吐出圧（（Ｐｘ－１）ＭＰａ）に一致させるのに必要とされる吐出量を求め、演算結果を目標吐出量演算部３０の目標吐出量補正部３０Ｃへ出力する。 When the PID control unit 30B inputs the calculation result from the maximum target discharge pressure selection unit 30A, the discharge pressure of the hydraulic pump 12 detected by the discharge pressure sensor 17 and the hydraulic pump 12 calculated by the maximum target discharge pressure selection unit 30A. By performing PID control on the target discharge pressure ((Px-1) MPa), the discharge amount required to make the discharge pressure of the hydraulic pump 12 coincide with the target discharge pressure ((Px-1) MPa) And the calculation result is output to the target discharge amount correction unit 30C of the target discharge amount calculation unit 30.
　目標吐出量補正部３０Ｃは、ＰＩＤ制御部３０Ｂから演算結果を入力すると、ＰＩＤ制御部３０Ｂで演算された吐出量に対して、エンジン回転数検出部１１Ａによって検出されたエンジン１１の回転数で除算して目標吐出量を求め、この演算結果を傾転量調整部１２Ａへ出力する。そして、傾転量調整部１２Ａは、目標吐出量補正部３０Ｃから演算結果を入力すると、油圧ポンプ１２の傾転量を調整して油圧ポンプ１２の吐出量を目標吐出量補正部３０Ｃで補正された目標吐出量に制御する。 When the target discharge amount correction unit 30C receives the calculation result from the PID control unit 30B, the target discharge amount correction unit 30C divides the discharge amount calculated by the PID control unit 30B by the rotation number of the engine 11 detected by the engine rotation number detection unit 11A. Thus, the target discharge amount is obtained, and the calculation result is output to the tilt amount adjustment unit 12A. When the calculation result is input from the target discharge amount correction unit 30C, the tilt amount adjustment unit 12A adjusts the tilt amount of the hydraulic pump 12, and the discharge amount of the hydraulic pump 12 is corrected by the target discharge amount correction unit 30C. The target discharge amount is controlled.
　流入制御部１９Ａの電磁比例減圧弁１９Ａ１が、リミッタ処理部２６Ａ２から指令電流Ｉｘ（０≦Ｉｘ＜Ｉｍａｘ）を入力すると、開口量を調整して２次側（旋回モータ３ａ側）の設定圧ＰＳをこの指令電流Ｉｘに対応した圧力Ｐｘ、すなわちＰＩＤ制御部２６Ａ１で演算された旋回駆動圧Ｐｘとなるように制御する。また、流入制御部１９Ｂの電磁比例減圧弁１９Ｂ１が、リミッタ処理部２６Ｂ２から指令電流Ｉｍａｘを入力すると、開口量を最小にして２次側（ブームシリンダ４ａ側）の設定圧ＰＳをこの指令電流Ｉｍａｘに対応した圧力（０ＭＰａ）に制御する。 When the electromagnetic proportional pressure reducing valve 19A1 of the inflow control unit 19A receives the command current Ix (0 ≦ Ix <Imax) from the limiter processing unit 26A2, the opening amount is adjusted and the set pressure PS on the secondary side (swing motor 3a side) is adjusted. Is controlled to be the pressure Px corresponding to the command current Ix, that is, the turning drive pressure Px calculated by the PID control unit 26A1. When the electromagnetic proportional pressure reducing valve 19B1 of the inflow control unit 19B receives the command current Imax from the limiter processing unit 26B2, the opening amount is minimized and the set pressure PS on the secondary side (boom cylinder 4a side) is set to the command current Imax. To a pressure (0 MPa) corresponding to.
　これにより、油圧ポンプ１２の吐出圧は、ＰＩＤ制御部２６Ａ１で演算された旋回駆動圧Ｐｘから所定値１ＭＰａを引算した圧力（（Ｐｘ－１）ＭＰａ）となり、吐出量は、旋回モータ３ａの速度を目標旋回速度ＶＲｍａｘに一致させる流量となる。 As a result, the discharge pressure of the hydraulic pump 12 becomes a pressure ((Px-1) MPa) obtained by subtracting a predetermined value 1 MPa from the swing drive pressure Px calculated by the PID control unit 26A1, and the discharge amount of the swing motor 3a The flow rate makes the speed coincide with the target turning speed VRmax.
　このとき、流入制御部１９Ａは、２次側（旋回モータ３ａ側）の圧力をＰＩＤ制御部２６Ａ１で演算された旋回駆動圧Ｐｘとなるように制御し、方向制御弁１６Ａを介して旋回モータ３ａに作用させることができる。すなわち、圧力制限部２５Ａ２による制限を受けることなく、旋回モータ３ａの速度を目標旋回速度ＶＲｍａｘに一致させることができるので、旋回モータ３ａの駆動力を十分に確保することができ、左操作レバー１５Ａの操作入力に対して旋回体３の高い速度制御性を得ることができる。これにより、旋回体３を迅速に加速して目標旋回速度で旋回させることができる。 At this time, the inflow control unit 19A controls the pressure on the secondary side (the swing motor 3a side) to be the swing drive pressure Px calculated by the PID control unit 26A1, and the swing motor 3a via the direction control valve 16A. Can act on. That is, the speed of the turning motor 3a can be matched with the target turning speed VRmax without being restricted by the pressure restricting portion 25A2, so that the driving force of the turning motor 3a can be sufficiently secured, and the left operation lever 15A High speed controllability of the revolving structure 3 can be obtained with respect to the operation input. Thereby, the revolving structure 3 can be rapidly accelerated and turned at the target turning speed.
　さらに、流入制御部１９Ａの１次側（油圧ポンプ１２側）の圧力（（Ｐｘ－１）ＭＰａ）は、２次側（旋回モータ３ａ側）の設定圧Ｐｘよりも所定値１ＭＰａ分小さいため、図６（ａ）で示す流入制御部１９Ａの電磁比例減圧弁１９Ａ１の２次側で生ずる圧力は所定値１ＭＰａ分だけ設定圧Ｐｘより小さくなる。この結果、電磁比例減圧弁１９Ａ１にフィードバックされる２次側の圧力（図６（ａ）の破線部）も設定圧Ｐｘより所定値１ＭＰａ分小さくなるため、ばね切換位置は電磁比例減圧弁１９Ａ１のばね１９ａ１と、電磁ソレノイド１９ａ２及びフィードバックされる２次側圧との間で力の平衡がとれず、最大開口面積となるＤ位置に移行する。その結果、電磁比例減圧弁１９Ａ１の１次側と２次側との圧力損失を必要最小限に抑えることができる。これにより、流入制御部１９Ａで生じる圧力損失を低減できるので、油圧回路内のエネルギー効率を高めることができる。 Further, the pressure ((Px-1) MPa) on the primary side (hydraulic pump 12 side) of the inflow control unit 19A is smaller than the set pressure Px on the secondary side (swing motor 3a side) by a predetermined value 1 MPa, The pressure generated on the secondary side of the electromagnetic proportional pressure reducing valve 19A1 of the inflow control unit 19A shown in FIG. 6A is smaller than the set pressure Px by a predetermined value 1 MPa. As a result, the secondary pressure fed back to the electromagnetic proportional pressure reducing valve 19A1 (the broken line portion in FIG. 6A) is also smaller than the set pressure Px by a predetermined value 1 MPa, so that the spring switching position is that of the electromagnetic proportional pressure reducing valve 19A1. The force is not balanced between the spring 19a1, the electromagnetic solenoid 19a2, and the secondary pressure fed back, and the position shifts to the D position where the maximum opening area is obtained. As a result, the pressure loss between the primary side and the secondary side of the electromagnetic proportional pressure reducing valve 19A1 can be minimized. Thereby, since the pressure loss which arises in 19 A of inflow control parts can be reduced, the energy efficiency in a hydraulic circuit can be improved.
　一方、電磁比例減圧弁１９Ｂ１は２次側（ブームシリンダ４ａ側）の設定圧ＰＳを指令電流Ｉｍａｘに対応した圧力（０ＭＰａ）に制御する、すなわち切換位置をＥ位置に移行するので、油圧ポンプ１２からブームシリンダ４ａへ作動油が吐出されても、作動油は電磁比例減圧弁１９Ｂ１で堰き止められる。さらに、方向制御弁１９Ｂが中立位置（図２に示すＢ位置）を維持しているので、油圧ポンプ１２の吐出圧がブームシリンダ４ａに作用することがなく、ブーム４Ａは停止した状態を保つ。 On the other hand, the electromagnetic proportional pressure reducing valve 19B1 controls the set pressure PS on the secondary side (boom cylinder 4a side) to a pressure (0 MPa) corresponding to the command current Imax, that is, the switching position is shifted to the E position. Even if hydraulic fluid is discharged from the boom cylinder 4a to the boom cylinder 4a, the hydraulic fluid is blocked by the electromagnetic proportional pressure reducing valve 19B1. Furthermore, since the directional control valve 19B maintains the neutral position (the B position shown in FIG. 2), the discharge pressure of the hydraulic pump 12 does not act on the boom cylinder 4a, and the boom 4A maintains the stopped state.
　次に、単独動作のうち左操作レバー１５Ａのハーフレバー操作が行われるときのコントローラ２０の制御動作を示す。なお、右操作レバー１５Ｂは操作されないので、コントローラ２０における目標速度演算部２５Ｂ１、圧力制限部２５Ｂ２、及び目標駆動圧演算部２６Ｂの制御動作は、上述した左操作レバー１５Ａのフルレバー操作が行われるときと同様であり、重複する説明を省略する。 Next, the control operation of the controller 20 when the half lever operation of the left operation lever 15A is performed in the single operation will be described. Since the right operation lever 15B is not operated, the control operation of the target speed calculation unit 25B1, the pressure limiting unit 25B2, and the target drive pressure calculation unit 26B in the controller 20 is performed when the above-described full operation of the left operation lever 15A is performed. And redundant description is omitted.
　キャブ７内の運転シートに着座した操作者は、左操作レバー１５Ａを左方向又は右方向へハーフレバー操作することにより、左操作レバー１５Ａの操作量に応じてパイロットポンプから吐出されたパイロット圧油が減圧される。そして、このパイロット圧油のパイロット圧が旋回モータ３ａ側の方向制御弁１６Ａに作用するので、方向制御弁１６Ａの切換位置が中立位置（図２に示すＢ位置）から左位置（図２に示すＡ位置）又は右位置（図２に示すＣ位置）に切り替えられ、方向制御弁１６Ａが左操作レバー１５Ａの操作量に応じて開口する。 The operator seated on the driving seat in the cab 7 operates the left operating lever 15A to the left or right by a half lever, so that the pilot pressure oil discharged from the pilot pump according to the operating amount of the left operating lever 15A is obtained. Is depressurized. Since the pilot pressure of this pilot pressure oil acts on the direction control valve 16A on the swing motor 3a side, the switching position of the direction control valve 16A is changed from the neutral position (position B shown in FIG. 2) to the left position (shown in FIG. 2). (A position) or right position (C position shown in FIG. 2), the direction control valve 16A opens according to the operation amount of the left operation lever 15A.
　このとき、操作量センサ１５Ａ１は左操作レバー１５Ａの操作量ＸＬとしてＸ１を検出し（０＜ＸＬ＝Ｘ１＜Ｘｍａｘ）、検出信号をコントローラ２０へ出力する。また、速度センサ１８Ａは旋回モータ３ａの速度を検出し、検出信号をコントローラ２０へ出力する。さらに、吐出圧センサ１７は油圧ポンプ１２の吐出圧を検出し、検出信号をコントローラ２０へ出力する。 At this time, the operation amount sensor 15A1 detects X1 as the operation amount XL of the left operation lever 15A (0 <XL = X1 <Xmax), and outputs a detection signal to the controller 20. The speed sensor 18 </ b> A detects the speed of the turning motor 3 a and outputs a detection signal to the controller 20. Further, the discharge pressure sensor 17 detects the discharge pressure of the hydraulic pump 12 and outputs a detection signal to the controller 20.
　コントローラ２０は操作量センサ１５Ａ１から検出信号を入力すると、コントローラ２０の目標速度演算部２５Ａ１が、目標速度テーブル２５ａ１の関数関係に対し、操作量センサ１５Ａ１で検出された操作量Ｘ１を適用することにより、目標旋回速度ＶＲとしてＶ１を求め（０＜ＶＲ＝Ｖ１＜ＶＲｍａｘ）、演算結果をコントローラ２０の目標駆動圧演算部２６Ａへ出力する。 When the controller 20 receives the detection signal from the operation amount sensor 15A1, the target speed calculation unit 25A1 of the controller 20 applies the operation amount X1 detected by the operation amount sensor 15A1 to the functional relationship of the target speed table 25a1. Then, V1 is obtained as the target turning speed VR (0 <VR = V1 <VRmax), and the calculation result is output to the target drive pressure calculation unit 26A of the controller 20.
　また、コントローラ２０の圧力制限部２５Ａ２は、上限圧力テーブル２５ａ２の関数関係に対し、操作量センサ１５Ａ１で検出された操作量Ｘ１を適用することにより、旋回駆動圧の上限圧力ＰＲを最小値ＰＲｍｉｎと最大値ＰＲｍａｘとの間の中間付近の圧力Ｐ１に設定し（ＰＲｍｉｎ＜ＰＲ＝Ｐ１＜ＰＲｍａｘ）、設定結果を目標駆動圧演算部２６Ａへ出力する。 Further, the pressure limiting unit 25A2 of the controller 20 applies the operation amount X1 detected by the operation amount sensor 15A1 to the functional relationship of the upper limit pressure table 25a2, thereby setting the upper limit pressure PR of the turning drive pressure to the minimum value PRmin. The pressure P1 is set in the vicinity of the middle between the maximum value PRmax (PRmin <PR = P1 <PRmax), and the setting result is output to the target drive pressure calculation unit 26A.
　目標駆動圧演算部２６Ａは、速度センサ１８Ａから検出信号、目標速度演算部２５Ａ１から演算結果、及び圧力制限部２５Ａ２から設定結果を入力すると、目標駆動圧演算部２６ＡのＰＩＤ制御部２６Ａ１が、速度センサ１８Ａで検出された旋回モータ３ａの速度と目標速度演算部２５Ａ１で演算された目標旋回速度Ｖ１（０＜Ｖ１＜ＶＲｍａｘ）に対してＰＩＤ制御を行うことにより、速度偏差を解消する、すなわち旋回モータ３ａの速度を目標旋回速度Ｖ１（０＜Ｖ１＜ＶＲｍａｘ）に一致させるのに必要とされる旋回駆動圧Ｐｙを求める。 When the target drive pressure calculator 26A receives the detection signal from the speed sensor 18A, the calculation result from the target speed calculator 25A1, and the setting result from the pressure limiter 25A2, the PID controller 26A1 of the target drive pressure calculator 26A PID control is performed on the speed of the turning motor 3a detected by the sensor 18A and the target turning speed V1 (0 <V1 <VRmax) calculated by the target speed calculation unit 25A1, thereby eliminating the speed deviation, that is, turning A turning drive pressure Py required to make the speed of the motor 3a coincide with the target turning speed V1 (0 <V1 <VRmax) is obtained.
　ここで、旋回体３の旋回動作のように慣性負荷が比較的大きい場合には、必要とされる旋回駆動圧が大きくなり易いが、実際には油圧回路内の圧力はリリーフ弁２１等によって制限されるので、油圧回路内の圧力の上限圧力として、例えばリリーフ弁２１の設定圧を上限圧力テーブル２５ａ２における上述の圧力Ｐ１（ＰＲｍｉｎ＜Ｐ１＜ＰＲｍａｘ）よりも大きいＰｒＬとし（Ｐ１＜ＰｒＬ）、リリーフ設定圧ＰｒＬをＰＩＤ制御部２６Ａ１の上限値として設定すれば、ＰＩＤ制御部２６Ａ１は慣性負荷が大きいために、目標速度演算部２５Ａ１で求めた目標速度と速度センサ１８で検出した速度との速度偏差の解消に時間を要することから、旋回駆動圧ＰｙがＰｒＬに達し、この演算結果を目標駆動圧演算部２６Ａのリミッタ処理部２６Ａ２へ出力する。なお、上限圧力の最大値ＰＲｍａｘをリリーフ設定圧ＰｒＬと同等以下の値に設定することで、各アクチュエータの目標駆動圧がリリーフ設定圧ＰｒＬを超過することがないため、通常リリーフ設定圧ＰｒＬを超過した際に生じるリリーフ弁２１から作動油タンク１３への排出流量を抑制でき、省エネ効果が得られる。 Here, when the inertia load is relatively large as in the turning operation of the swing body 3, the required swing drive pressure tends to increase, but the pressure in the hydraulic circuit is actually limited by the relief valve 21 or the like. Therefore, as the upper limit pressure of the pressure in the hydraulic circuit, for example, the set pressure of the relief valve 21 is set to PrL larger than the above-described pressure P1 (PRmin <P1 <PRmax) in the upper limit pressure table 25a2 (P1 <PrL). If the set pressure PrL is set as the upper limit value of the PID control unit 26A1, since the PID control unit 26A1 has a large inertia load, the speed deviation between the target speed obtained by the target speed calculation unit 25A1 and the speed detected by the speed sensor 18 Since it takes time to eliminate the rotation, the turning drive pressure Py reaches PrL, and this calculation result is used as the limiter processing unit 2 of the target drive pressure calculation unit 26A. And outputs it to the A2. Note that the target drive pressure of each actuator does not exceed the relief setting pressure PrL by setting the maximum value PRmax of the upper limit pressure to a value equal to or less than the relief setting pressure PrL, and thus exceeds the normal relief setting pressure PrL. Thus, the flow rate discharged from the relief valve 21 to the hydraulic oil tank 13 can be suppressed, and an energy saving effect can be obtained.
　リミッタ処理部２６Ａ２は、ＰＩＤ制御部２６Ａ１から演算結果を入力すると、ＰＩＤ制御部２６Ａ１で演算された旋回駆動圧ＰｒＬと圧力制限部２５Ａ２で設定された旋回駆動圧の上限圧力Ｐ１を比較する。このとき、上述したようにＰＩＤ制御部２６Ａ１で演算された旋回駆動圧ＰｒＬは圧力制限部２５Ａ２で設定された旋回駆動圧の上限圧力Ｐ１よりも大きいので（Ｐ１＜ＰｒＬ）、ＰＩＤ制御部２６Ａ１で演算された旋回駆動圧ＰｒＬは圧力制限部２５Ａ２による制限を受ける。 When the calculation result is input from the PID control unit 26A1, the limiter processing unit 26A2 compares the swing drive pressure PrL calculated by the PID control unit 26A1 with the upper limit pressure P1 of the swing drive pressure set by the pressure limiting unit 25A2. At this time, as described above, the turning drive pressure PrL calculated by the PID control unit 26A1 is larger than the upper limit pressure P1 of the turning drive pressure set by the pressure limiting unit 25A2 (P1 <PrL), so the PID control unit 26A1. The calculated turning drive pressure PrL is limited by the pressure limiting unit 25A2.
　従って、リミッタ処理部２６Ａ２は、圧力制限部２５Ａ２で設定された旋回駆動圧の上限圧力Ｐ１を目標旋回駆動圧として求め、指令電流Ｉとして目標旋回駆動圧Ｐ１に対応するＩ１を流入制御部１９Ａへ出力すると共に（０≦Ｉ＝Ｉ１＜Ｉｍａｘ）、目標旋回駆動圧Ｐ１から所定値１ＭＰａを引算した演算結果をコントローラ２０の目標吐出量演算部３０へ出力する。 Accordingly, the limiter processing unit 26A2 obtains the upper limit pressure P1 of the turning drive pressure set by the pressure limiting unit 25A2 as the target turning drive pressure, and uses I1 corresponding to the target turning drive pressure P1 as the command current I to the inflow control unit 19A. In addition to outputting (0 ≦ I = I1 <Imax), a calculation result obtained by subtracting a predetermined value 1 MPa from the target turning drive pressure P1 is output to the target discharge amount calculation unit 30 of the controller 20.
　次に、目標吐出量演算部３０の最大目標吐出圧選択部３０Ａは、リミッタ処理部２６Ａ２，２６Ｂ２から演算結果を入力すると、リミッタ処理部２６Ａ２から入力した入力値（（Ｐ１－１）ＭＰａ）とリミッタ処理部２６Ｂ２から入力した入力値（０ＭＰａ）を比較する。このとき、上述したようにリミッタ処理部２６Ａ２から入力した入力値（（Ｐ１－１）ＭＰａ）は、圧力制限部２５Ａ２で設定された旋回駆動圧の上限圧力Ｐ１から所定値１ＭＰａを引算した値であり、０ＭＰａ以上となるので、リミッタ処理部２６Ｂ２から入力した入力値（０ＭＰａ）よりも大きい。従って、最大目標吐出圧選択部３０Ａは、リミッタ処理部２６Ａ２から入力した入力値（（Ｐ１－１）ＭＰａ）を選択して油圧ポンプ１２の目標吐出圧として求め、この演算結果を目標吐出量演算部３０のＰＩＤ制御部３０Ｂへ出力する。 Next, when the maximum target discharge pressure selection unit 30A of the target discharge amount calculation unit 30 inputs the calculation results from the limiter processing units 26A2 and 26B2, the input value ((P1-1) MPa) input from the limiter processing unit 26A2 and The input value (0 MPa) input from the limiter processing unit 26B2 is compared. At this time, as described above, the input value ((P1-1) MPa) input from the limiter processing unit 26A2 is a value obtained by subtracting the predetermined value 1 MPa from the upper limit pressure P1 of the turning drive pressure set by the pressure limiting unit 25A2. Since it is 0 MPa or more, it is larger than the input value (0 MPa) input from the limiter processing unit 26B2. Accordingly, the maximum target discharge pressure selection unit 30A selects the input value ((P1-1) MPa) input from the limiter processing unit 26A2 and obtains it as the target discharge pressure of the hydraulic pump 12, and calculates the calculation result as a target discharge amount calculation. To the PID control unit 30B of the unit 30.
　ＰＩＤ制御部３０Ｂは、最大目標吐出圧選択部３０Ａから演算結果を入力すると、吐出圧センサ１７で検出された油圧ポンプ１２の吐出圧と最大目標吐出圧選択部３０Ａで演算された油圧ポンプ１２の目標吐出圧（（Ｐ１－１）ＭＰａ）に対してＰＩＤ制御を行うことにより、油圧ポンプ１２の吐出圧を目標吐出圧（（Ｐ１－１）ＭＰａ）に一致させるのに必要とされる吐出量を求め、演算結果を目標吐出量演算部３０の目標吐出量補正部３０Ｃへ出力する。 When the PID control unit 30B inputs the calculation result from the maximum target discharge pressure selection unit 30A, the discharge pressure of the hydraulic pump 12 detected by the discharge pressure sensor 17 and the hydraulic pump 12 calculated by the maximum target discharge pressure selection unit 30A. By performing PID control on the target discharge pressure ((P1-1) MPa), the discharge amount required to make the discharge pressure of the hydraulic pump 12 coincide with the target discharge pressure ((P1-1) MPa) And the calculation result is output to the target discharge amount correction unit 30C of the target discharge amount calculation unit 30.
　目標吐出量補正部３０Ｃは、ＰＩＤ制御部３０Ｂから演算結果を入力すると、ＰＩＤ制御部３０Ｂで演算された吐出量に対して、エンジン回転数検出部１１Ａによって検出されたエンジン１１の回転数で除算して目標吐出量を求め、演算結果を傾転量調整部１２Ａへ出力する。そして、傾転量調整部１２Ａは、目標吐出量補正部３０Ｃから演算結果を入力すると、油圧ポンプ１２の傾転量を調整して油圧ポンプ１２の吐出量を目標吐出量補正部３０Ｃで補正された目標吐出量に制御する。 When the target discharge amount correction unit 30C receives the calculation result from the PID control unit 30B, the target discharge amount correction unit 30C divides the discharge amount calculated by the PID control unit 30B by the rotation number of the engine 11 detected by the engine rotation number detection unit 11A. Thus, the target discharge amount is obtained, and the calculation result is output to the tilt amount adjustment unit 12A. When the calculation result is input from the target discharge amount correction unit 30C, the tilt amount adjustment unit 12A adjusts the tilt amount of the hydraulic pump 12, and the discharge amount of the hydraulic pump 12 is corrected by the target discharge amount correction unit 30C. The target discharge amount is controlled.
　また、流入制御部１９Ａの電磁比例減圧弁１９Ａ１が、リミッタ処理部２６Ａ２から指令電流Ｉ１を入力すると、開口量を調整して２次側（旋回モータ３ａ側）の設定圧ＰＳをこの指令電流Ｉ１に対応した圧力Ｐ１、すなわち圧力制限部２５Ａ２で設定された旋回駆動圧の上限圧力Ｐ１となるように制御する。また、流入制御部１９Ｂの電磁比例減圧弁１９Ｂ１が、リミッタ処理部２６Ｂ２から指令電流Ｉｍａｘを入力すると、開口量を最小にして２次側（ブームシリンダ４ａ側）の設定圧ＰＳをこの指令電流Ｉｍａｘに対応した圧力（０ＭＰａ）に制御する。 Further, when the electromagnetic proportional pressure reducing valve 19A1 of the inflow control unit 19A receives the command current I1 from the limiter processing unit 26A2, the opening amount is adjusted and the set pressure PS on the secondary side (swing motor 3a side) is set to the command current I1. Is controlled so as to be the upper limit pressure P1 of the turning drive pressure set by the pressure limiting unit 25A2. When the electromagnetic proportional pressure reducing valve 19B1 of the inflow control unit 19B receives the command current Imax from the limiter processing unit 26B2, the opening amount is minimized and the set pressure PS on the secondary side (boom cylinder 4a side) is set to the command current Imax. To a pressure (0 MPa) corresponding to.
　これにより、油圧ポンプ１２の吐出圧は、圧力制限部２５Ａ２で設定された旋回駆動圧の上限圧力Ｐ１から所定値１ＭＰａを引算した圧力（（Ｐ１－１）ＭＰａ）となり、吐出量は、吐出圧（（Ｐ１－１）ＭＰａ）で定まる流量となる。 As a result, the discharge pressure of the hydraulic pump 12 becomes a pressure ((P1-1) MPa) obtained by subtracting the predetermined value 1 MPa from the upper limit pressure P1 of the turning drive pressure set by the pressure limiting unit 25A2, and the discharge amount is set to the discharge pressure. The flow rate is determined by the pressure ((P1-1) MPa).
　このとき、流入制御部１９Ａは、２次側（旋回モータ３ａ側）の圧力を圧力制限部２５Ａ２で設定された旋回駆動圧の上限圧力Ｐ１となるように制御し、方向制御弁１６Ａを介して旋回モータ３ａに作用させることができる。 At this time, the inflow control unit 19A controls the pressure on the secondary side (swing motor 3a side) to be the upper limit pressure P1 of the swing drive pressure set by the pressure limiting unit 25A2, and via the direction control valve 16A. It can be made to act on the turning motor 3a.
　すなわち、ＰＩＤ制御部２６Ａ１で演算された旋回駆動圧Ｐｙが大きくても、圧力制限部２５Ａ２による制限を受けることにより、圧力制限部２５Ａ２で設定された旋回駆動圧の上限圧力Ｐ１を超える圧力が旋回モータ３ａに作用することがないので、旋回モータ３ａの駆動力を抑制して旋回体３を旋回させることができる。これにより、圧力制限部２５Ａ２で設定された旋回駆動圧の上限圧力Ｐ１以下の範囲で速度制御性を確保しつつ、左操作レバー１５Ａの操作入力に対して旋回体３の高い力制御性を得ることができる。従って、操作者は旋回モータ３ａの駆動力に制御がかかるときの操作感覚を得ることができ、旋回体３の旋回動作にかかる負荷を左操作レバー１５Ａの操作感覚で把握しながら作業を行うことができる。 That is, even if the turning drive pressure Py calculated by the PID control unit 26A1 is large, the pressure exceeding the upper limit pressure P1 of the turning drive pressure set by the pressure limiting unit 25A2 is swung by being limited by the pressure limiting unit 25A2. Since it does not act on the motor 3a, the driving force of the turning motor 3a can be suppressed and the turning body 3 can be turned. Thereby, high force controllability of the swing body 3 is obtained with respect to the operation input of the left operation lever 15A while ensuring speed controllability within the range of the upper limit pressure P1 of the swing drive pressure set by the pressure limiting unit 25A2. be able to. Therefore, the operator can obtain an operation feeling when the driving force of the turning motor 3a is controlled, and can perform work while grasping the load applied to the turning operation of the turning body 3 with the operation feeling of the left operation lever 15A. Can do.
　特に、旋回体３が旋回して加速した後、ＰＩＤ制御部２６Ａ１で演算された旋回駆動圧Ｐｙが圧力制限部２５Ａ２で設定された旋回駆動圧の上限圧力Ｐ１以下になると、圧力制限部２５Ａ２による制限を受けなくなるので、上述した左操作レバー１５Ａのフルレバー操作が行われたときの動作と同様に、ＰＩＤ制御部２６Ａ１で演算された旋回駆動圧Ｐｙを旋回モータ３ａに作用させることができ、旋回体３の速度制御性をより高めることができる。 In particular, after the turning body 3 turns and accelerates, when the turning drive pressure Py calculated by the PID control unit 26A1 becomes equal to or lower than the upper limit pressure P1 of the turning drive pressure set by the pressure restriction unit 25A2, the pressure restriction unit 25A2 Since the restriction is not applied, the turning drive pressure Py calculated by the PID control unit 26A1 can be applied to the turning motor 3a similarly to the operation when the full lever operation of the left operation lever 15A is performed. The speed controllability of the body 3 can be further improved.
　さらに、流入制御部１９Ａの１次側（油圧ポンプ１２側）の圧力（（Ｐ１－１）ＭＰａ）は、２次側（旋回モータ３ａ側）の設定圧Ｐ１よりも所定値１ＭＰａ分だけ小さいため、上述した左操作レバー１５Ａのフルレバー操作が行われたときの動作と同様、電磁比例減圧弁１９Ａ１の１次側と２次側との圧力損失を必要最小限に抑えることができる。これにより、左操作レバー１５Ａのハーフレバー操作が行われたときでも、流入制御部１９Ａで生じる圧力損失を低減できるので、油圧回路内のエネルギー効率を高めることができる。 Further, the pressure ((P1-1) MPa) on the primary side (hydraulic pump 12 side) of the inflow control unit 19A is smaller than the set pressure P1 on the secondary side (swing motor 3a side) by a predetermined value 1 MPa. Similarly to the operation when the full lever operation of the left operation lever 15A is performed, the pressure loss between the primary side and the secondary side of the electromagnetic proportional pressure reducing valve 19A1 can be suppressed to a necessary minimum. Thereby, even when the half lever operation of the left operation lever 15A is performed, the pressure loss generated in the inflow control unit 19A can be reduced, so that the energy efficiency in the hydraulic circuit can be increased.
　一方、電磁比例減圧弁１９Ｂ１は閉じて２次側（ブームシリンダ４ａ側）の設定圧ＰＳを指令電流Ｉｍａｘに対応した圧力（０ＭＰａ）に制御する、すなわち切換位置をＥ位置に移行するので、油圧ポンプ１２からブームシリンダ４ａへ作動油が吐出されても、作動油は電磁比例減圧弁１９Ｂ１で堰き止められる。さらに、方向制御弁１９Ｂが中立位置（図２に示すＢ位置）を維持しているので、油圧ポンプ１２の吐出圧がブームシリンダ４ａに作用することがなく、ブーム４Ａは停止した状態を保つ。 On the other hand, the electromagnetic proportional pressure reducing valve 19B1 is closed to control the set pressure PS on the secondary side (boom cylinder 4a side) to a pressure (0 MPa) corresponding to the command current Imax, that is, the switching position is shifted to the E position. Even if the hydraulic oil is discharged from the pump 12 to the boom cylinder 4a, the hydraulic oil is blocked by the electromagnetic proportional pressure reducing valve 19B1. Furthermore, since the directional control valve 19B maintains the neutral position (the B position shown in FIG. 2), the discharge pressure of the hydraulic pump 12 does not act on the boom cylinder 4a, and the boom 4A maintains the stopped state.
　次に、複合動作のうち左操作レバー１５Ａのハーフレバー操作が行われ、右操作レバー１５Ｂのハーフレバー操作が行われるときのコントローラ２０の制御動作を示す。なお、コントローラ２０における目標速度演算部２５Ａ１、圧力制限部２５Ａ２、及び目標駆動圧演算部２６Ａの制御動作は、上述した左操作レバー１５Ａのハーフレバー操作が行われるときと同様であり、重複する説明を省略する。 Next, the control operation of the controller 20 when the half lever operation of the left operation lever 15A is performed and the half lever operation of the right operation lever 15B is performed in the combined operation will be described. Note that the control operations of the target speed calculation unit 25A1, the pressure limiting unit 25A2, and the target drive pressure calculation unit 26A in the controller 20 are the same as when the above-described half lever operation of the left operation lever 15A is performed, and overlapping descriptions are given. Is omitted.
　キャブ７内の運転シートに着座した操作者は、右操作レバー１５Ｂを前方向又は後方向へハーフレバー操作することにより、右操作レバー１５Ｂの操作量に応じてパイロットポンプから吐出されたパイロット圧油が減圧される。そして、このパイロット圧油のパイロット圧がブームシリンダ４ａ側の方向制御弁１６Ｂに作用するので、方向制御弁１６Ｂの切換位置が中立位置（図２に示すＢ位置）から左位置（図２に示すＡ位置）又は右位置（図２に示すＣ位置）に切り替えられ、方向制御弁１６Ｂが右操作レバー１５Ｂの操作量に応じて開口する。 The operator seated on the driving seat in the cab 7 operates the right operation lever 15B halfway forward or rearward, thereby pilot pressure oil discharged from the pilot pump according to the operation amount of the right operation lever 15B. Is depressurized. Since the pilot pressure of the pilot pressure oil acts on the direction control valve 16B on the boom cylinder 4a side, the switching position of the direction control valve 16B is changed from the neutral position (position B shown in FIG. 2) to the left position (shown in FIG. 2). The position control valve 16B is opened according to the amount of operation of the right operation lever 15B by switching to the A position) or the right position (C position shown in FIG. 2).
　このとき、操作量センサ１５Ｂ１は右操作レバー１５Ｂの操作量ＸＲとしてＸ２を検出し（０＜ＸＲ＝Ｘ２＜ＸＲｍａｘ）、検出信号をコントローラ２０へ出力する。また、速度センサ１８Ａはブームシリンダ４ａの速度を検出し、検出信号をコントローラ２０へ出力する。さらに、吐出圧センサ１７は油圧ポンプ１２の吐出圧を検出し、検出信号をコントローラ２０へ出力する。 At this time, the operation amount sensor 15B1 detects X2 as the operation amount XR of the right operation lever 15B (0 <XR = X2 <XRmax), and outputs a detection signal to the controller 20. The speed sensor 18 </ b> A detects the speed of the boom cylinder 4 a and outputs a detection signal to the controller 20. Further, the discharge pressure sensor 17 detects the discharge pressure of the hydraulic pump 12 and outputs a detection signal to the controller 20.
　コントローラ２０は操作量センサ１５Ｂ１から検出信号を入力すると、コントローラ２０の目標速度演算部２５Ｂ１が、目標速度テーブル２５ｂ１の関数関係に対し、操作量センサ１５Ｂ１で検出された操作量Ｘ２（０＜Ｘ２＜ＸＲｍａｘ）を適用することにより、目標ブーム速度ＶＢとしてＶ２を求め（０＜ＶＢ＝Ｖ２＜ＶＢｍａｘ）、演算結果をコントローラ２０の目標駆動圧演算部２６Ｂへ出力する。 When the controller 20 receives the detection signal from the operation amount sensor 15B1, the target speed calculation unit 25B1 of the controller 20 performs the operation amount X2 (0 <X2 <) detected by the operation amount sensor 15B1 with respect to the functional relationship of the target speed table 25b1. XRmax) is applied to obtain V2 as the target boom speed VB (0 <VB = V2 <VBmax), and the calculation result is output to the target drive pressure calculation unit 26B of the controller 20.
　また、コントローラ２０の圧力制限部２５Ｂ２は、上限圧力テーブル２５ｂ２の関数関係に対し、操作量センサ１５Ｂ１で検出された操作量Ｘ２を適用することにより、ブーム駆動圧の上限圧力ＰＢを最小値ＰＢｍｉｎと最大値ＰＢｍａｘとの間にある圧力Ｐ２に設定し（ＰＢｍｉｎ＜ＰＢ＝Ｐ２＜ＰＢｍａｘ）、設定結果を目標駆動圧演算部２６Ｂへ出力する。 Further, the pressure limiting unit 25B2 of the controller 20 applies the operation amount X2 detected by the operation amount sensor 15B1 to the functional relationship of the upper limit pressure table 25b2, thereby setting the upper limit pressure PB of the boom drive pressure to the minimum value PBmin. The pressure P2 is set to a pressure P2 between the maximum value PBmax (PBmin <PB = P2 <PBmax), and the setting result is output to the target drive pressure calculator 26B.
　目標駆動圧演算部２６Ｂは、速度センサ１８Ｂから検出信号、目標速度演算部２５Ｂ１から演算結果、及び圧力制限部２５Ｂ２から設定結果を入力すると、目標駆動圧演算部２６ＢのＰＩＤ制御部２６Ｂ１が、速度センサ１８Ｂで検出されたブームシリンダ４ａの速度と目標速度演算部２５Ｂ１で演算された目標ブーム速度Ｖ２に対してＰＩＤ制御を行うことにより、速度偏差を解消する、すなわちブームシリンダ４ａの速度を目標ブーム速度Ｖ２に一致させるのに必要とされるブーム駆動圧Ｐｚを求める。 When the target drive pressure calculation unit 26B receives the detection signal from the speed sensor 18B, the calculation result from the target speed calculation unit 25B1, and the setting result from the pressure limiting unit 25B2, the PID control unit 26B1 of the target drive pressure calculation unit 26B By performing PID control on the speed of the boom cylinder 4a detected by the sensor 18B and the target boom speed V2 calculated by the target speed calculation unit 25B1, the speed deviation is eliminated, that is, the speed of the boom cylinder 4a is set to the target boom. A boom driving pressure Pz required to match the speed V2 is obtained.
　ここで、上述した旋回体３の旋回動作と同様に、ブーム４Ａの回動動作に対する慣性負荷は比較的大きく、油圧回路内の圧力がリリーフ弁２１等によって制限されるので、油圧回路内の圧力の上限圧力として、例えばリリーフ弁２１の設定圧を上限圧力テーブル２５ｂ２における圧力Ｐ２よりも大きい上述のＰＩＤ制御部２６Ａ１と同様、ＰｒＬとすると（Ｐ２＜ＰｒＬ）、ＰＩＤ制御部２６Ｂ１で演算されるブーム駆動圧は、上述と同様、ＰｒＬとなる。ＰＩＤ制御部２６Ｂ１は、ブーム駆動圧ＰｚとしてＰｒＬを求め、この演算結果を目標駆動圧演算部２６Ｂのリミッタ処理部２６Ｂ２へ出力する。 Here, similarly to the turning operation of the revolving structure 3 described above, the inertia load with respect to the turning operation of the boom 4A is relatively large, and the pressure in the hydraulic circuit is limited by the relief valve 21 or the like. For example, if the set pressure of the relief valve 21 is set to PrL (P2 <PrL) in the same manner as the above-described PID control unit 26A1 that is larger than the pressure P2 in the upper limit pressure table 25b2, the boom calculated by the PID control unit 26B1 is used. The driving pressure is PrL as described above. The PID control unit 26B1 obtains PrL as the boom drive pressure Pz and outputs the calculation result to the limiter processing unit 26B2 of the target drive pressure calculation unit 26B.
　リミッタ処理部２６Ｂ２は、ＰＩＤ制御部２６Ｂ１から演算結果を入力すると、ＰＩＤ制御部２６Ｂ１で演算されたブーム駆動圧ＰｒＬと圧力制限部２５Ｂ２で設定されたブーム駆動圧の上限圧力Ｐ２を比較する。このとき、上述したようにＰＩＤ制御部２６Ｂ１で演算されたブーム駆動圧ＰｒＬは圧力制限部２５Ｂ２で設定されたブーム駆動圧の上限圧力Ｐ２よりも大きいので（Ｐ２＜ＰｒＬ）、ＰＩＤ制御部２６Ｂ１で演算されたブーム駆動圧ＰｒＬは圧力制限部２５Ｂ２による制限を受ける。 When the calculation result is input from the PID control unit 26B1, the limiter processing unit 26B2 compares the boom driving pressure PrL calculated by the PID control unit 26B1 with the upper limit pressure P2 of the boom driving pressure set by the pressure limiting unit 25B2. At this time, as described above, the boom drive pressure PrL calculated by the PID control unit 26B1 is larger than the upper limit pressure P2 of the boom drive pressure set by the pressure limiting unit 25B2 (P2 <PrL), so the PID control unit 26B1. The calculated boom drive pressure PrL is limited by the pressure limiting unit 25B2.
　従って、リミッタ処理部２６Ｂ２は、圧力制限部２５Ｂ２で設定された旋回駆動圧の上限圧力Ｐ２を目標ブーム駆動圧として求め、指令電流Ｉとして目標ブーム駆動圧Ｐ２に対応するＩ２を流入制御部１９Ａへ出力すると共に（０≦Ｉ＝Ｉ２＜Ｉｍａｘ）、目標ブーム駆動圧Ｐ２から所定値１ＭＰａを引算した演算結果を目標吐出量演算部３０へ出力する。 Therefore, the limiter processing unit 26B2 obtains the upper limit pressure P2 of the turning drive pressure set by the pressure limiting unit 25B2 as the target boom drive pressure, and uses the command current I as I2 corresponding to the target boom drive pressure P2 to the inflow control unit 19A. While outputting (0 ≦ I = I2 <Imax), a calculation result obtained by subtracting a predetermined value 1 MPa from the target boom drive pressure P2 is output to the target discharge amount calculation unit 30.
　次に、目標吐出量演算部３０の最大目標吐出圧選択部３０Ａは、リミッタ処理部２６Ａ２，２６Ｂ２から演算結果を入力すると、リミッタ処理部２６Ａ２から入力した入力値（（Ｐ１－１）ＭＰａ）とリミッタ処理部２６Ｂ２から入力した入力値（（Ｐ２－１）ＭＰａ）を比較する。 Next, when the maximum target discharge pressure selection unit 30A of the target discharge amount calculation unit 30 inputs the calculation results from the limiter processing units 26A2 and 26B2, the input value ((P1-1) MPa) input from the limiter processing unit 26A2 and The input value ((P2-1) MPa) input from the limiter processing unit 26B2 is compared.
　ここで、上限圧力テーブル２５ａ２の関数関係における旋回駆動圧の上限圧力Ｐ１が上限圧力テーブル２５ｂ２の関数関係におけるブーム駆動圧の上限圧力Ｐ２よりも大きく設定されている場合には（Ｐ１＞Ｐ２）、リミッタ処理部２６Ａ２から入力した入力値（（Ｐ１－１）ＭＰａ）は、リミッタ処理部２６Ｂ２から入力した入力値（（Ｐ２－１）ＭＰａ）よりも大きくなる。従って、最大目標吐出圧選択部３０Ａは、リミッタ処理部２６Ａ２から入力した入力値（（Ｐ１－１）ＭＰａ）を選択して油圧ポンプ１２の目標吐出圧として求め、この演算結果を目標吐出量演算部３０のＰＩＤ制御部３０Ｂへ出力する。 Here, when the upper limit pressure P1 of the swing drive pressure in the functional relationship of the upper limit pressure table 25a2 is set larger than the upper limit pressure P2 of the boom drive pressure in the functional relationship of the upper limit pressure table 25b2 (P1> P2), The input value ((P1-1) MPa) input from the limiter processing unit 26A2 is larger than the input value ((P2-1) MPa) input from the limiter processing unit 26B2. Accordingly, the maximum target discharge pressure selection unit 30A selects the input value ((P1-1) MPa) input from the limiter processing unit 26A2 and obtains it as the target discharge pressure of the hydraulic pump 12, and calculates the calculation result as a target discharge amount calculation. To the PID control unit 30B of the unit 30.
　ＰＩＤ制御部３０Ｂは、最大目標吐出圧選択部３０Ａから演算結果を入力すると、吐出圧センサ１７で検出された油圧ポンプ１２の吐出圧と最大目標吐出圧選択部３０Ａで演算された油圧ポンプ１２の目標吐出圧（（Ｐ１－１）ＭＰａ）に対してＰＩＤ制御を行うことにより、油圧ポンプ１２の吐出圧を目標吐出圧（（Ｐ１－１）ＭＰａ）に一致させるのに必要とされる吐出量を求め、この演算結果を目標吐出量演算部３０の目標吐出量補正部３０Ｃへ出力する。 When the PID control unit 30B inputs the calculation result from the maximum target discharge pressure selection unit 30A, the discharge pressure of the hydraulic pump 12 detected by the discharge pressure sensor 17 and the hydraulic pump 12 calculated by the maximum target discharge pressure selection unit 30A. By performing PID control on the target discharge pressure ((P1-1) MPa), the discharge amount required to make the discharge pressure of the hydraulic pump 12 coincide with the target discharge pressure ((P1-1) MPa) The calculation result is output to the target discharge amount correction unit 30C of the target discharge amount calculation unit 30.
　目標吐出量補正部３０Ｃは、ＰＩＤ制御部３０Ｂから演算結果を入力すると、ＰＩＤ制御部３０Ｂで演算された吐出量に対して、エンジン回転数検出部１１Ａによって検出されたエンジン１１の回転数で除算して目標吐出量を求め、この演算結果を傾転量調整部１２Ａへ出力する。そして、傾転量調整部１２Ａは、目標吐出量補正部３０Ｃから演算結果を入力すると、油圧ポンプ１２の傾転量を調整して油圧ポンプ１２の吐出量を目標吐出量補正部３０Ｃで補正された目標吐出量に制御する。 When the target discharge amount correction unit 30C receives the calculation result from the PID control unit 30B, the target discharge amount correction unit 30C divides the discharge amount calculated by the PID control unit 30B by the rotation number of the engine 11 detected by the engine rotation number detection unit 11A. Thus, the target discharge amount is obtained, and the calculation result is output to the tilt amount adjustment unit 12A. When the calculation result is input from the target discharge amount correction unit 30C, the tilt amount adjustment unit 12A adjusts the tilt amount of the hydraulic pump 12, and the discharge amount of the hydraulic pump 12 is corrected by the target discharge amount correction unit 30C. The target discharge amount is controlled.
　また、流入制御部１９Ａの電磁比例減圧弁１９Ａ１が、リミッタ処理部２６Ａ２から指令電流Ｉ１を入力すると、開口量を調整して２次側（旋回モータ３ａ側）の設定圧ＰＳをこの指令電流Ｉ１に対応した圧力Ｐ１、すなわち圧力制限部２５Ａ２で設定された旋回駆動圧の上限圧力Ｐ１となるように制御する。また、流入制御部１９Ｂの電磁比例減圧弁１９Ｂ１が、リミッタ処理部２６Ｂ２から指令電流Ｉ２を入力すると、開口量を調整して２次側（ブームシリンダ４ａ側）の設定圧ＰＳをこの指令電流Ｉ２に対応した圧力Ｐ２、すなわち圧力制限部２５Ｂ２で設定されたブーム駆動圧の上限圧力Ｐ２となるように制御する。 Further, when the electromagnetic proportional pressure reducing valve 19A1 of the inflow control unit 19A receives the command current I1 from the limiter processing unit 26A2, the opening amount is adjusted and the set pressure PS on the secondary side (swing motor 3a side) is set to the command current I1. Is controlled so as to be the upper limit pressure P1 of the turning drive pressure set by the pressure limiting unit 25A2. Further, when the electromagnetic proportional pressure reducing valve 19B1 of the inflow control unit 19B receives the command current I2 from the limiter processing unit 26B2, the opening amount is adjusted and the set pressure PS on the secondary side (the boom cylinder 4a side) is set to the command current I2. Is controlled so as to become the upper limit pressure P2 of the boom driving pressure set by the pressure limiting unit 25B2.
　これにより、油圧ポンプ１２の吐出圧は、圧力制限部２５Ａ２で設定された旋回駆動圧の上限圧力Ｐ１から所定値１ＭＰａを引算した圧力（（Ｐ１－１）ＭＰａ）となり、吐出量は、旋回モータ３ａ及びブームシリンダ４ａに対し、吐出圧（（Ｐ１－１）ＭＰａ）で定まる流量となる。従って、上述した左操作レバー１５Ａのハーフレバー操作のときと同様の作用効果を得ることができる。 As a result, the discharge pressure of the hydraulic pump 12 becomes a pressure ((P1-1) MPa) obtained by subtracting a predetermined value 1 MPa from the upper limit pressure P1 of the swing drive pressure set by the pressure limiter 25A2, and the discharge amount is the swing speed. The flow rate is determined by the discharge pressure ((P1-1) MPa) with respect to the motor 3a and the boom cylinder 4a. Accordingly, it is possible to obtain the same operation and effect as the above-described half lever operation of the left operation lever 15A.
　一方、電磁比例減圧弁１９Ｂ１は、２次側（ブームシリンダ４ａ側）の設定圧ＰＳを圧力制限部２５Ｂ２で設定された旋回駆動圧の上限圧力Ｐ２（＜Ｐ１）に制御しているので、流入制御部１９Ａの１次側（油圧ポンプ１２側）の圧力（（Ｐ１－１）ＭＰａ）が２次側（ブームシリンダ４ａ側）の設定圧Ｐ２よりも大きくなり、油圧ポンプ１２から吐出された作動油は電磁比例減圧弁１９Ｂ１でこの設定圧Ｐ２に相当する流量に調整される。これにより、圧力制限部２５Ｂ２で設定されたブーム駆動圧の上限圧力Ｐ２を方向制御弁１６Ｂを介してブームシリンダ４ａに作用させることができる。 On the other hand, since the electromagnetic proportional pressure reducing valve 19B1 controls the set pressure PS on the secondary side (boom cylinder 4a side) to the upper limit pressure P2 (<P1) of the turning drive pressure set by the pressure limiting unit 25B2, The pressure ((P1-1) MPa) on the primary side (hydraulic pump 12 side) of the control unit 19A becomes larger than the set pressure P2 on the secondary side (boom cylinder 4a side), and the operation discharged from the hydraulic pump 12 The oil is adjusted to a flow rate corresponding to the set pressure P2 by the electromagnetic proportional pressure reducing valve 19B1. Thereby, the upper limit pressure P2 of the boom drive pressure set by the pressure limiting unit 25B2 can be applied to the boom cylinder 4a via the direction control valve 16B.
　すなわち、ＰＩＤ制御部２６Ｂ１で演算されたブーム駆動圧Ｐｚが大きくても、圧力制限部２５Ｂ２による制限を受けることにより、圧力制限部２５Ｂ２で設定されたブーム駆動圧の上限圧力Ｐ２を超える圧力がブームシリンダ４ａに作用することがないので、ブームシリンダ４ａの駆動力を抑制してブーム４Ａを回動させることができる。これにより、圧力制限部２５Ｂ２で設定されたブーム駆動圧の上限圧力Ｐ２以下の範囲で速度制御性を確保しつつ、右操作レバー１５Ｂの操作入力に対してブーム４Ａの高い力制御性を得ることができる。従って、操作者はブームシリンダ４ａの駆動力に制御がかかるときの操作感
覚を得ることができ、ブーム４Ａの回動動作にかかる負荷を右操作レバー１５Ｂの操作感覚で把握しながら作業を行うことができる。 That is, even if the boom drive pressure Pz calculated by the PID control unit 26B1 is large, the boom exceeds the upper limit pressure P2 of the boom drive pressure set by the pressure limiter 25B2 due to the restriction by the pressure limiter 25B2. Since it does not act on the cylinder 4a, the boom 4A can be rotated while suppressing the driving force of the boom cylinder 4a. As a result, high force controllability of the boom 4A can be obtained with respect to the operation input of the right operation lever 15B, while ensuring speed controllability within the range of the boom drive pressure upper limit pressure P2 set by the pressure limiter 25B2. Can do. Therefore, the operator can obtain an operation feeling when the driving force of the boom cylinder 4a is controlled, and can perform an operation while grasping the load applied to the rotation operation of the boom 4A with the operation feeling of the right operation lever 15B. Can do.
　特に、ブーム４Ａが回動して加速した後、ＰＩＤ制御部２６Ｂ１で演算されたブーム駆動圧Ｐｚが圧力制限部２５Ｂ２で設定されたブーム駆動
圧の上限圧力Ｐ２以下になると、圧力制限部２５Ｂ２による制限を受けなくなるので、上述した左操作レバー１５Ａのフルレバー操作が行われたときの動作と同様に、ＰＩＤ制御部２６Ｂ１で演算されたブーム駆動圧Ｐｚをブームシリンダ４ａに作用させることができ、ブーム４Ａの速度制御性をより高めることができる。 In particular, when the boom driving pressure Pz calculated by the PID control unit 26B1 becomes equal to or lower than the upper limit pressure P2 of the boom driving pressure set by the pressure limiting unit 25B2 after the boom 4A is rotated and accelerated, the pressure limiting unit 25B2 Since there is no restriction, the boom drive pressure Pz calculated by the PID control unit 26B1 can be applied to the boom cylinder 4a in the same manner as the operation when the full lever operation of the left operation lever 15A is performed. The speed controllability of 4A can be further improved.
　このように構成した本発明の第１実施形態によれば、操作レバー１５Ａ，１５Ｂの動作組合せに拘わらず、操作レバー１５Ａ，１５Ｂの操作入力に対して旋回モータ３ａ及びブームシリンダ４ａの速度制御性を確保しつつ、力制御性を十分に向上させることができる。これにより、旋回モータ３ａ及びブームシリンダ４ａの安定した動作を実現でき、滑らかな操作感覚が得られるので、操作レバー１５Ａ，１５Ｂの操作性能を高めることができ、油圧ショベル１の作業効率を高めることができる。特に、本発明の第１実施形態では、各操作レバー１５Ａ，１５Ｂの操作がフルレバー操作に近い程、得られる速度制御性によって旋回体３及びブーム４Ａに対して優れた加速性能を発揮できるので、各操作レバー１５Ａ，１５Ｂの操作量を大きくすることにより、操作者が意図する速度も容易に得ることができる。 According to the first embodiment of the present invention configured as described above, the speed controllability of the swing motor 3a and the boom cylinder 4a with respect to the operation input of the operation levers 15A and 15B regardless of the operation combination of the operation levers 15A and 15B. The force controllability can be sufficiently improved while ensuring the above. Thereby, stable operation of the swing motor 3a and the boom cylinder 4a can be realized, and a smooth operation feeling can be obtained. Therefore, the operation performance of the operation levers 15A and 15B can be improved, and the working efficiency of the hydraulic excavator 1 can be improved. Can do. In particular, in the first embodiment of the present invention, the closer the operation of the operation levers 15A and 15B is to the full lever operation, the more excellent acceleration performance can be exerted on the swing body 3 and the boom 4A by the speed controllability obtained. By increasing the operation amount of each operation lever 15A, 15B, the speed intended by the operator can be easily obtained.
　また、本発明の第１実施形態は、流入制御部１９Ａ，１９Ｂの圧力制御弁として電磁比例減圧弁１９Ａ１，１９Ｂ１を用いているので、旋回モータ３ａ及びブームシリンダ４ａへ流入する作動油の流量の制御を電磁比例減圧弁１９Ａ１，１９Ｂ１によって容易に実行できるので、油圧回路が複雑にならず、油圧回路を効率良く製造することができる。これにより、油圧回路の製造工程における作業者の負担を軽減することができ、製造効率を高めることができる。さらに、各電磁比例減圧弁１９Ａ１，１９Ｂ１は、２次側（旋回モータ３ａ側、ブームシリンダ４ａ側）の設定圧ＰＳを入力された指令電流Ｉに応じて制御することにより、２次側（旋回モータ３ａ側、ブームシリンダ４ａ側）の圧力を設定圧ＰＳ以下に調整しているので、油圧ポンプ１２から旋回モータ３ａ及びブームシリンダ４ａへ作動油を精度良く導くことができる。 In the first embodiment of the present invention, since the electromagnetic proportional pressure reducing valves 19A1 and 19B1 are used as the pressure control valves of the inflow control units 19A and 19B, the flow rate of the hydraulic oil flowing into the swing motor 3a and the boom cylinder 4a is controlled. Since the control can be easily executed by the electromagnetic proportional pressure reducing valves 19A1 and 19B1, the hydraulic circuit is not complicated, and the hydraulic circuit can be efficiently manufactured. Thereby, the burden of the operator in the manufacturing process of a hydraulic circuit can be reduced, and manufacturing efficiency can be improved. Further, the electromagnetic proportional pressure reducing valves 19A1 and 19B1 control the secondary side (swing motor 3a side, boom cylinder 4a side) set pressure PS in accordance with the input command current I, thereby controlling the secondary side (swinging). Since the pressure on the motor 3a side and the boom cylinder 4a side) is adjusted to be equal to or lower than the set pressure PS, the hydraulic oil can be accurately guided from the hydraulic pump 12 to the swing motor 3a and the boom cylinder 4a.
　また、本発明の第１実施形態は、電磁比例減圧弁１９Ａ１，１９Ｂ１は、指令電流Ｉの大きさが所定の電流値ＩＡ以上のとき、２次側（旋回モータ３ａ側、ブームシリンダ４ａ側）の設定圧ＰＳが指令電流Ｉの大きさに対して反比例し、指令電流Ｉの大きさが所定の電流値ＩＡ未満のとき、最大値ＰＳｍａｘとなる開口量、すなわち最大開口面積に調整しているので、目標駆動圧演算部２６Ａ，２６Ｂから指令電流Ｉを入力していないときでも（Ｉ＝０Ａ）、開口した状態を保つことができる。従って、指令電流Ｉが導通する図示しない配線に、断線等の不具合が生じた場合でも、電磁比例減圧弁１９Ａ１，１９Ｂ１は開口しているので、操作者は操作レバー１５Ａ，１５Ｂを操作することにより、旋回モータ３ａ及びブームシリンダ４ａの駆動圧を確保して旋回モータ３ａ及びブームシリンダ４ａを確実に動作させることができ、油圧ショベル１の高い信頼性を確保することができる。 In the first embodiment of the present invention, the electromagnetic proportional pressure reducing valves 19A1 and 19B1 are arranged on the secondary side (the swing motor 3a side and the boom cylinder 4a side) when the magnitude of the command current I is equal to or greater than a predetermined current value IA. When the set pressure PS is inversely proportional to the magnitude of the command current I and the magnitude of the command current I is less than the predetermined current value IA, the opening amount is adjusted to the maximum value PSmax, that is, the maximum opening area. Therefore, even when the command current I is not input from the target drive pressure calculation units 26A and 26B (I = 0A), the opened state can be maintained. Therefore, even when a failure such as disconnection occurs in a wiring (not shown) through which the command current I is conducted, the electromagnetic proportional pressure reducing valves 19A1 and 19B1 are open, so that the operator operates the operation levers 15A and 15B. Thus, the driving pressure of the swing motor 3a and the boom cylinder 4a can be ensured, and the swing motor 3a and the boom cylinder 4a can be operated reliably, and the high reliability of the hydraulic excavator 1 can be ensured.
　さらに、本発明の第１実施形態では、油圧ポンプ１２の吐出圧を所定値分低くしたため、流入制御部１９Ａ，１９Ｂの負荷が最も高い方は、最大開口で作動油をアクチュエータに流量を供給できるので、圧力損失を必要最小限に抑えることができ、省エネルギー化を図ることができる。また、目標吐出量演算部３０の目標吐出量補正部３０Ｃは、ＰＩＤ制御部３０Ｂから入力した吐出量に対してエンジン回転数検出部１１Ａによって検出されたエンジン１１の回転数で除算して補正することにより、エンジン１１の回転数が大きく変動してもその影響を抑制することができるので、油圧ポンプ１２の吐出量の制御を安定して行うことができる。 Furthermore, in the first embodiment of the present invention, the discharge pressure of the hydraulic pump 12 is lowered by a predetermined value, so that the one with the highest load on the inflow control units 19A and 19B can supply the hydraulic oil to the actuator at the maximum opening. Therefore, the pressure loss can be minimized and energy saving can be achieved. Further, the target discharge amount correction unit 30C of the target discharge amount calculation unit 30 divides and corrects the discharge amount input from the PID control unit 30B by the engine speed detected by the engine speed detection unit 11A. Thus, even if the rotational speed of the engine 11 fluctuates greatly, the influence can be suppressed, so that the discharge amount of the hydraulic pump 12 can be controlled stably.
［第２実施形態］
　図７は本発明の第２実施形態に備えられたコントローラの構成を示す図、図８は本発明の第２実施形態に備えられた関係補正部によって補正された旋回モータに関する目標速度テーブルの関数関係を説明する図、図９は本発明の第２実施形態に備えられた関係補正部によって補正されたブームシリンダに関する目標速度テーブルの関数関係を説明する図である。 [Second Embodiment]
FIG. 7 is a diagram showing a configuration of a controller provided in the second embodiment of the present invention, and FIG. 8 is a function of a target speed table related to the turning motor corrected by the relation correcting unit provided in the second embodiment of the present invention. FIG. 9 is a diagram for explaining the relationship, and FIG. 9 is a diagram for explaining the functional relationship of the target speed table related to the boom cylinder corrected by the relationship correction unit provided in the second embodiment of the present invention.
　本発明に係る作業機械の油圧制御装置の第２実施形態は、前述した第１実施形態の構成に加え、例えば図７に示すように目標速度テーブル２５ａ１の関数関係を目標駆動圧演算部２６Ａによって演算された目標旋回駆動圧に応じて補正する関係補正部３５Ａと、目標速度テーブル２５ｂ１の関数関係を目標駆動圧演算部２６Ｂによって演算された目標ブーム駆動圧に応じて補正する関係補正部３５Ｂとを備えている。なお、本発明の第２実施形態の基本構成は第１実施形態と同じであり、第１実施形態と同一又は対応する部分には同一の符号を付し、重複する説明を省略している。 In the second embodiment of the hydraulic control device for a work machine according to the present invention, in addition to the configuration of the first embodiment described above, for example, as shown in FIG. 7, the functional relationship of the target speed table 25a1 is determined by the target drive pressure calculator 26A. A relationship correction unit 35A that corrects the calculated target turning drive pressure according to the target boom drive pressure; a relationship correction unit 35B that corrects the functional relationship of the target speed table 25b1 according to the target boom drive pressure calculated by the target drive pressure calculation unit 26B; It has. The basic configuration of the second embodiment of the present invention is the same as that of the first embodiment, and the same or corresponding parts as those of the first embodiment are denoted by the same reference numerals, and redundant description is omitted.
　具体的には、図７、図８に示すように、関係補正部３５Ａは、例えば目標駆動圧演算部２６Ａによって演算された目標旋回駆動圧を入力し、この目標旋回駆動圧が大きい程、目標速度テーブル２５ａ１の関数関係において操作量ＸＬに対する目標旋回速度ＶＲの傾きの絶対値を減少させる補正を行うようにしている。そして、目標速度演算部２５Ａ１は、関係補正部３５Ａによって補正された目標速度テーブル２５ａ１の関数関係に対し、操作量センサ１５Ａ１によって検出された操作量ＸＬを適用して目標旋回速度ＶＲを演算するようにしている。 Specifically, as shown in FIGS. 7 and 8, the relationship correction unit 35A inputs the target turning drive pressure calculated by the target drive pressure calculation unit 26A, for example, and the larger the target turning drive pressure, the more the target In the functional relationship of the speed table 25a1, correction is performed to reduce the absolute value of the gradient of the target turning speed VR with respect to the operation amount XL. Then, the target speed calculation unit 25A1 calculates the target turning speed VR by applying the operation amount XL detected by the operation amount sensor 15A1 to the functional relationship of the target speed table 25a1 corrected by the relationship correction unit 35A. I have to.
　同様に、図７、図９に示すように関係補正部３５Ｂは、例えば目標駆動圧演算部２６Ｂによって演算された目標ブーム駆動圧を入力し、この目標ブーム駆動圧が大きい程、目標速度テーブル２５ｂ１の関数関係において操作量ＸＲに対する目標ブーム速度ＶＢの傾きの絶対値を減少させる補正を行うようにしている。そして、目標速度演算部２５Ｂ１は、関係補正部３５Ｂによって補正された目標速度テーブル２５ｂ１の関数関係に対し、操作量センサ１５Ｂ１によって検出された操作量ＸＲを適用して目標ブーム速度ＶＢを演算するようにしている。 Similarly, as shown in FIGS. 7 and 9, the relationship correction unit 35B inputs, for example, the target boom drive pressure calculated by the target drive pressure calculation unit 26B, and the target speed table 25b1 increases as the target boom drive pressure increases. In such a functional relationship, correction is performed to reduce the absolute value of the inclination of the target boom speed VB with respect to the operation amount XR. Then, the target speed calculation unit 25B1 calculates the target boom speed VB by applying the operation amount XR detected by the operation amount sensor 15B1 to the functional relationship of the target speed table 25b1 corrected by the relationship correction unit 35B. I have to.
　このように構成した本発明の第２実施形態によれば、上述した第１実施形態と同様の作用効果が得られる他、関係補正部３５Ａが目標速度テーブル２５ａ１の関数関係を目標駆動圧演算部２６Ａによって演算された目標旋回速度に応じて補正し、関係補正部３５Ｂが目標速度テーブル２５ｂ１の関数関係を目標駆動圧演算部２６Ｂによって演算された目標ブーム速度に応じて補正することにより、速度制御性と力制御性が容易に調整できる。例えば、重量のある岩石などの掘削や、溝掘削時に溝側面の土砂が崩れないように固めるためにバケット４Ｃの側面を、旋回を用いて溝側面に押し当てる旋回横当て動作など、速度制御と力制御との移行が容易に行える。すなわち、上述した動作では、操作レバー１５Ａ，１５Ｂを介して与えた目標速度に対し、負荷が大きいために油圧アクチュエータの速度がほぼ０を維持した状態となるため、目標速度と油圧アクチュエータの速度との速度偏差がすぐには解消せず、目標駆動圧演算部２６Ａ，２６ＢのＰＩＤ制御部２６Ａ１，２６Ｂ１で求められる目標駆動圧が増大し、さらにはリミッタ処理部２６Ａ２，２６Ｂ２の上限圧力に到達する。このとき、目標駆動圧の増加に伴い、目標速度を低減するため、油圧ポンプ１２からの吐出量を抑えつつ、増加した目標駆動圧、すなわち力を与えることができる。また、これらの負荷が解消された場合には、目標速度と油圧アクチュエータの速度との速度偏差が解消し、目標駆動圧が低下するので、それに伴い、目標速度が増大し、油圧ポンプ１２からの吐出量を増やし、目標速度に応じた速度が与えられる。 According to the second embodiment of the present invention configured as described above, the same function and effect as those of the first embodiment described above can be obtained, and the relationship correction unit 35A determines the functional relationship of the target speed table 25a1 as the target drive pressure calculation unit. The correction is made according to the target turning speed calculated by 26A, and the relationship correction unit 35B corrects the functional relationship of the target speed table 25b1 according to the target boom speed calculated by the target drive pressure calculation unit 26B, thereby speed control. And force controllability can be adjusted easily. For example, speed control, such as excavation of heavy rocks, or swivel lateral movement operation that presses the side surface of the bucket 4C against the groove side surface using swiveling in order to solidify so that the sediment on the groove side surface does not collapse during groove excavation. Easy transition to force control. That is, in the above-described operation, since the load is large with respect to the target speed given via the operation levers 15A and 15B, the speed of the hydraulic actuator is maintained at almost zero. However, the target drive pressure obtained by the PID control units 26A1 and 26B1 of the target drive pressure calculation units 26A and 26B increases, and further reaches the upper limit pressure of the limiter processing units 26A2 and 26B2. . At this time, in order to reduce the target speed as the target drive pressure increases, the increased target drive pressure, that is, a force can be applied while suppressing the discharge amount from the hydraulic pump 12. Further, when these loads are eliminated, the speed deviation between the target speed and the speed of the hydraulic actuator is eliminated, and the target driving pressure is reduced. Accordingly, the target speed is increased and the hydraulic pump 12 The discharge amount is increased, and a speed according to the target speed is given.
　このように、速度制御と力制御との調整が容易である他、力制御の場合には、油圧ポンプ１２の吐出量を抑えることができ、リリーフ弁２１より排出させる無効な流量を抑制し、省エネ性を向上できる。 Thus, in addition to easy adjustment between speed control and force control, in the case of force control, the discharge amount of the hydraulic pump 12 can be suppressed, the invalid flow rate discharged from the relief valve 21 is suppressed, Energy saving can be improved.
［第３実施形態］
　図１０は本発明の第３実施形態に備えられた流入制御部について説明する図であり、（ａ）図は流入制御部を構成する電磁比例絞り弁の構成を示す図、（ｂ）図は電磁比例絞り弁の特性を示す図、図１１は本発明の第３実施形態に備えられたコントローラの構成を示す図である。 [Third Embodiment]
FIG. 10 is a diagram for explaining an inflow control unit provided in the third embodiment of the present invention. FIG. 10A is a diagram showing a configuration of an electromagnetic proportional throttle valve constituting the inflow control unit, and FIG. The figure which shows the characteristic of an electromagnetic proportional throttle valve, FIG. 11 is a figure which shows the structure of the controller with which 3rd Embodiment of this invention was equipped.
　本発明の第３実施形態が前述した第１実施形態と異なるのは、第１実施形態では、図６（ａ）に示すように各流入制御部１９Ａ，１９Ｂが、通過する作動油の圧力を制御する圧力制御弁として電磁比例減圧弁１９Ａ１，１９Ｂ１を含んでいるのに対して、第３実施形態では、電磁比例減圧弁１９Ａ１，１９Ｂ１の代わりに、例えば図１０（ａ）に示すように圧力制御弁として電磁比例絞り弁１９Ａ２，１９Ｂ２を含んでいることである。なお、本発明の第３実施形態の基本構成は第１実施形態と同じであり、第１実施形態と同一又は対応する部分には同一の符号を付し、重複する説明を省略している。 The third embodiment of the present invention differs from the first embodiment described above in the first embodiment in that each inflow control unit 19A, 19B determines the pressure of hydraulic fluid that passes through as shown in FIG. 6 (a). While the electromagnetic proportional pressure reducing valves 19A1 and 19B1 are included as pressure control valves to be controlled, in the third embodiment, instead of the electromagnetic proportional pressure reducing valves 19A1 and 19B1, for example, as shown in FIG. It is that electromagnetic proportional throttle valves 19A2 and 19B2 are included as control valves. The basic configuration of the third embodiment of the present invention is the same as that of the first embodiment, and the same or corresponding parts as those of the first embodiment are denoted by the same reference numerals, and redundant description is omitted.
　本発明の第３実施形態では、各電磁比例絞り弁１９Ａ２，１９Ｂ２は、例えば第１実施形態と同様に、１次側（油圧ポンプ１２側）と２次側（旋回モータ３ａ側、ブームシリンダ４ａ側）を連通する方向へ本体を付勢するばね１９ａ１，１９ｂ１を有している。各電磁比例絞り弁１９Ａ２，１９Ｂ２は、図１０（ｂ）に示すように指令電流Ｉの大きさが所定の電流値ＩＢ未満のとき、開口面積Ａが最大値Ａｍａｘとなり、指令電流Ｉの大きさが所定の電流値ＩＢ以上のとき、開口面積Ａが指令電流Ｉの大きさに対して反比例し、指令電流Ｉの大きさが最大値Ｉｍａｘのとき、開口面積Ａが０Ａになるように開口量を調整して２次側（旋回モータ３ａ側、ブームシリンダ４ａ側）の圧力を制御している。 In the third embodiment of the present invention, each of the electromagnetic proportional throttle valves 19A2 and 19B2 includes, for example, a primary side (hydraulic pump 12 side) and a secondary side (swing motor 3a side, boom cylinder 4a) as in the first embodiment. Springs 19a1 and 19b1 for urging the main body in the direction in which the side) communicates. As shown in FIG. 10B, each of the electromagnetic proportional throttle valves 19A2 and 19B2 has an opening area A that is a maximum value Amax when the magnitude of the command current I is less than a predetermined current value IB, and the magnitude of the command current I. Is larger than the predetermined current value IB, the opening area A is inversely proportional to the magnitude of the command current I, and when the magnitude of the command current I is the maximum value Imax, the opening amount is set so that the opening area A becomes 0A. Is adjusted to control the pressure on the secondary side (swing motor 3a side, boom cylinder 4a side).
　すなわち、各電磁比例絞り弁１９Ａ２，１９Ｂ２は、指令電流Ｉの大きさが所定の電流値ＩＢ未満のとき、ばね１９ａ１，１９ｂ１の弾性力によって１次側（油圧ポンプ１２側）と２次側（旋回モータ３ａ側、ブームシリンダ４ａ側）を連通する切換位置（図１０（ａ）に示すＦ位置）に保ち、指令電流Ｉの大きさが所定の電流値ＩＢ以上のとき、ばね１９ａ１，１９ｂ１の弾性力に抗して本体が移動し、１次側（油圧ポンプ１２側）と２次側（旋回モータ３ａ側、ブームシリンダ４ａ側）を遮断する切換位置（図１０（ａ）に示すＧ位置）へ切り替えるようにしている。 That is, when the magnitude of the command current I is less than the predetermined current value IB, each of the electromagnetic proportional throttle valves 19A2 and 19B2 has a primary side (hydraulic pump 12 side) and a secondary side (side of the hydraulic pump 12) by the elastic force of the springs 19a1 and 19b1. When the magnitude of the command current I is greater than or equal to a predetermined current value IB when the swing motor 3a side and the boom cylinder 4a side) are kept in the switching position (the F position shown in FIG. 10A), the springs 19a1 and 19b1 Switching position (G position shown in FIG. 10 (a)) in which the main body moves against the elastic force and the primary side (hydraulic pump 12 side) and the secondary side (swing motor 3a side, boom cylinder 4a side) are cut off. ).
　本発明の第３実施形態では、コントローラ２０は、図１１に示すように目標吐出量演算部３０の最大目標吐出圧選択部３０Ａによって演算された目標吐出圧と目標駆動圧演算部２６Ａによって演算された目標旋回駆動圧との差圧を演算する差圧演算部２７Ａと、最大目標吐出圧選択部３０Ａによって演算された目標吐出圧と目標駆動圧演算部２６Ｂによって演算された目標ブーム駆動圧との差を演算する差圧演算部２７Ｂとを有している。 In the third embodiment of the present invention, the controller 20 is calculated by the target discharge pressure and target drive pressure calculator 26A calculated by the maximum target discharge pressure selector 30A of the target discharge amount calculator 30 as shown in FIG. The differential pressure calculation unit 27A that calculates the differential pressure with the target turning drive pressure, the target discharge pressure calculated by the maximum target discharge pressure selection unit 30A, and the target boom drive pressure calculated by the target drive pressure calculation unit 26B And a differential pressure calculation unit 27B that calculates the difference.
　また、コントローラ２０は、差圧演算部２７Ａによって演算された差圧及び目標速度演算部２５Ａ１によって演算された目標旋回速度に基づいて、電磁比例絞り弁１９Ａ２の開口面積Ａを演算する開口面積演算部２８Ａと、差圧演算部２７Ｂによって演算された差圧及び目標速度演算部２５Ｂ１によって演算された目標ブーム速度に基づいて、電磁比例絞り弁１９Ｂ２の開口面積Ａを演算する開口面積演算部２８Ｂとを有している。 The controller 20 calculates an opening area A of the electromagnetic proportional throttle valve 19A2 based on the differential pressure calculated by the differential pressure calculator 27A and the target turning speed calculated by the target speed calculator 25A1. 28A and an opening area calculation unit 28B for calculating the opening area A of the electromagnetic proportional throttle valve 19B2 based on the differential pressure calculated by the differential pressure calculation unit 27B and the target boom speed calculated by the target speed calculation unit 25B1. Have.
　ここで、各電磁比例絞り弁１９Ａ２，１９Ｂ２を流通する流量をＱ、開口面積をＡ、１次側（油圧ポンプ１２側）と２次側（旋回モータ３ａ側、ブームシリンダ４ａ側）との有効差圧をΔＰ、作動油の密度をρ、流量係数をＣとすると、一般的に以下の数式（１）が成立する。
Figure JPOXMLDOC01-appb-M000001
 Here, the flow rate through each of the electromagnetic proportional throttle valves 19A2 and 19B2 is Q, the opening area is A, the primary side (hydraulic pump 12 side) and the secondary side (swing motor 3a side, boom cylinder 4a side) are effective. When the differential pressure is ΔP, the hydraulic fluid density is ρ, and the flow coefficient is C, the following formula (1) is generally established.
Figure JPOXMLDOC01-appb-M000001
　数式（１）を整理すると、数式（２）が成立する。
Figure JPOXMLDOC01-appb-M000002
 When formula (1) is arranged, formula (2) is established.
Figure JPOXMLDOC01-appb-M000002
　従って、流量Ｑは目標速度演算部２５Ａ１によって演算された目標旋回速度と旋回モータ３ａの仕様であるモータ容量との積、また、１次側（油圧ポンプ１２側）と２次側（旋回モータ３ａ側）との有効差圧ΔＰは、差圧演算部２７Ａによって演算された差圧、から各々求められ、作動油の密度ρ及び流量係数Ｃはそれぞれ所定の定数であるので、開口面積演算部２８Ａは、差圧演算部２７Ａによって演算された差圧、目標速度演算部２５Ａ１によって演算された目標旋回速度、及び上述の数式（２）を用いて電磁比例絞り弁１９Ａ２の開口面積Ａを演算するようにしている。 Therefore, the flow rate Q is the product of the target turning speed calculated by the target speed calculating unit 25A1 and the motor capacity that is the specification of the turning motor 3a, and the primary side (hydraulic pump 12 side) and the secondary side (turning motor 3a). The effective differential pressure ΔP is calculated from the differential pressure calculated by the differential pressure calculation unit 27A, and the density ρ and the flow coefficient C of the hydraulic oil are respectively predetermined constants. Therefore, the opening area calculation unit 28A Calculates the opening area A of the electromagnetic proportional throttle valve 19A2 using the differential pressure calculated by the differential pressure calculation unit 27A, the target turning speed calculated by the target speed calculation unit 25A1, and the above equation (2). I have to.
　同様に、流量Ｑは目標速度演算部２５Ｂ１によって演算された目標ブーム速度とブームシリンダ４ａの受圧面積との積、また、１次側（油圧ポンプ１２側）と２次側（ブームシリンダ４ａ側）との有効差圧ΔＰは、差圧演算部２７Ｂによって演算された差圧、から各々求められ、作動油の密度ρ及び流量係数Ｃはそれぞれ所定の定数であるので、開口面積演算部２８Ｂは、差圧演算部２７Ｂによって演算された差圧、目標速度演算部２５Ｂ１によって演算された目標ブーム速度、及び上述の数式（２）を用いて電磁比例絞り弁１９Ｂ２の開口面積Ａを演算するようにしている。 Similarly, the flow rate Q is the product of the target boom speed calculated by the target speed calculator 25B1 and the pressure receiving area of the boom cylinder 4a, and the primary side (hydraulic pump 12 side) and secondary side (boom cylinder 4a side). The effective differential pressure ΔP is obtained from the differential pressure calculated by the differential pressure calculation unit 27B, and the hydraulic fluid density ρ and the flow coefficient C are respectively predetermined constants. The opening area A of the electromagnetic proportional throttle valve 19B2 is calculated using the differential pressure calculated by the differential pressure calculation unit 27B, the target boom speed calculated by the target speed calculation unit 25B1, and the above equation (2). Yes.
　なお、油圧アクチュエータ３ａ，４ａのうち負荷が最も高い油圧アクチュエータでは、有効差圧ΔＰは所定値１ＭＰａ分だけ負の値となるが、この場合は、開口面積演算部２８Ａ，２８Ｂにて電磁比例絞り弁１９Ａ２，１９Ｂ２に対し切換位置をＦ位置に移行するように演算を行う。 In the hydraulic actuator having the highest load among the hydraulic actuators 3a and 4a, the effective differential pressure ΔP becomes a negative value by a predetermined value of 1 MPa. In this case, the opening area calculation units 28A and 28B use an electromagnetic proportional throttle. An operation is performed on the valves 19A2 and 19B2 so as to shift the switching position to the F position.
　このように構成した本発明の第３実施形態によれば、上述した第１実施形態と同様の作用効果が得られる他、流入制御部１９Ａ，１９Ｂの圧力制御弁として電磁比例絞り弁１９Ａ２，１９Ｂ２を用いることにより、油圧回路を小型化できるので、製造コストを削減することができる。これにより、高い生産性を実現することができる。 According to the third embodiment of the present invention configured as described above, the same operational effects as those of the first embodiment described above can be obtained, and electromagnetic proportional throttle valves 19A2 and 19B2 can be used as pressure control valves of the inflow control units 19A and 19B. Since the hydraulic circuit can be miniaturized, the manufacturing cost can be reduced. Thereby, high productivity can be realized.
　なお、上述した本発明の第１～３実施形態は、油圧ショベル１が、油圧ポンプ１２と、旋回モータ３ａ、ブームシリンダ４ａ、アームシリンダ４ｂ、及びバケットシリンダ４ａの４つの油圧アクチュエータとを備えた場合について説明したが、この場合に限らず、例えば油圧ポンプは２つ以上あっても良いし、油圧アクチュエータは、旋回モータ３ａ、ブームシリンダ４ａ、アームシリンダ４ｂ、及びバケットシリンダ４ａ以外のものを含んでも良い。 In the first to third embodiments of the present invention described above, the hydraulic excavator 1 includes the hydraulic pump 12 and the four hydraulic actuators of the swing motor 3a, the boom cylinder 4a, the arm cylinder 4b, and the bucket cylinder 4a. Although the case has been described, the present invention is not limited to this case. For example, there may be two or more hydraulic pumps, and the hydraulic actuator includes other than the swing motor 3a, the boom cylinder 4a, the arm cylinder 4b, and the bucket cylinder 4a. But it ’s okay.
　また、本発明の第１～３実施形態は、目標駆動圧演算部２６Ａが、演算した目標旋回駆動圧から所定値１ＭＰａだけ低い値を演算結果として目標吐出量演算部３０へ出力し、目標駆動圧演算部２６Ｂが、演算した目標ブーム駆動圧から所定値１ＭＰａだけ低い値を演算結果として目標吐出量演算部３０へ出力するようにした場合について説明したが、この場合に限らず、当該所定値は、油圧アクチュエータ３ａ，４ａの制御の精度の観点から０ＭＰａに近い値の方が好ましいが、油圧ポンプ１２の圧力制御や流入制御部１９Ａ，１９Ｂの制御等の精度から生じる制御のばらつきを考慮して設定しても良い。さらに所定値を設けず、目標駆動圧をそのまま目標吐出量演算部３０へ出力しても良い。この場合、図３、図７、図１１のリミッタ処理部２６Ａ２，２６Ｂ２から最大目標吐出圧選択部３０Ａに出力される駆動圧と、リミッタ処理部２６Ａ２，２６Ｂ２から流入制御部１９Ａ、１９Ｂに出力される駆動圧は同じ値となる。 In the first to third embodiments of the present invention, the target drive pressure calculation unit 26A outputs a value lower than the calculated target turning drive pressure by a predetermined value 1 MPa to the target discharge amount calculation unit 30 as a calculation result, and the target drive The case where the pressure calculation unit 26B outputs a value lower than the calculated target boom drive pressure by the predetermined value 1 MPa as the calculation result to the target discharge amount calculation unit 30 has been described. Is preferably close to 0 MPa from the viewpoint of the accuracy of control of the hydraulic actuators 3a and 4a. However, in consideration of control variations caused by the accuracy of the pressure control of the hydraulic pump 12 and the control of the inflow control units 19A and 19B, etc. May be set. Further, the target drive pressure may be output to the target discharge amount calculation unit 30 as it is without providing a predetermined value. In this case, the drive pressure output from the limiter processing units 26A2 and 26B2 to the maximum target discharge pressure selecting unit 30A and the limiter processing units 26A2 and 26B2 to the inflow control units 19A and 19B in FIGS. The driving pressure is the same value.
　また、本発明の第１実施形態は、目標速度演算部２５Ａ１の目標速度テーブル２５ａ１及び圧力制限部２５Ａ２の上限圧力テーブル２５ａ２の各関数関係は、旋回体３の旋回動作に対して要求される性能を考慮して設定され、目標速度演算部２５Ｂ１の目標速度テーブル２５ｂ１及び圧力制限部２５Ｂ２の上限圧力テーブル２５ｂ２の各関数関係は、ブーム４Ａの回動動作に対して要求される性能を考慮して設定された場合について説明したが、この場合に限るものではない。 Further, according to the first embodiment of the present invention, each functional relationship between the target speed table 25a1 of the target speed calculation unit 25A1 and the upper limit pressure table 25a2 of the pressure limiting unit 25A2 is the performance required for the swing operation of the swing body 3. The functional relationship between the target speed table 25b1 of the target speed calculation unit 25B1 and the upper limit pressure table 25b2 of the pressure limiting unit 25B2 takes into consideration the performance required for the pivoting operation of the boom 4A. Although the case of setting has been described, the present invention is not limited to this case.
　例えば、目標速度テーブル２５ａ１及び上限圧力テーブル２５ａ２の各関数関係は、旋回体３の旋回動作と他の動作部位４Ａ～４Ｃとの動作バランスを考慮して設定され、目標速度テーブル２５ｂ１及び上限圧力テーブル２５ｂ２の各関数関係は、ブーム４Ａの回動動作と他の動作部位３ａ，４Ｂ，４Ｃとの動作バランスを考慮して設定されても良い。 For example, the functional relationship between the target speed table 25a1 and the upper limit pressure table 25a2 is set in consideration of the balance between the turning operation of the swing body 3 and the other operation parts 4A to 4C. The target speed table 25b1 and the upper limit pressure table Each functional relationship of 25b2 may be set in consideration of the operation balance between the rotation operation of the boom 4A and the other operation parts 3a, 4B, 4C.
　また、油圧ショベル１のキャブ７が、重負荷作業を行うパワーモード及び軽負荷作業を行うエコノミーモード等の作業モードを設定する作業モード設定部を有し、目標速度テーブル２５ａ１，２５ｂ１及び上限圧力テーブル２５ａ２，２５ｂ２の各関数関係は、作業モードに応じて複数設定され、作業モード設定部で設定された作業モードに連動して切り替えるようにしても良い。 Further, the cab 7 of the excavator 1 has a work mode setting unit for setting work modes such as a power mode for performing heavy load work and an economy mode for performing light load work, and includes target speed tables 25a1 and 25b1 and upper limit pressure tables. A plurality of functional relationships 25a2 and 25b2 may be set according to the work mode, and may be switched in conjunction with the work mode set by the work mode setting unit.
　また、本発明の第２実施形態は、目標速度演算部２５Ａ１は、例えば目標駆動圧演算部２６Ａによって演算された目標旋回駆動圧が大きい程、目標速度テーブル２５ａ１の関数関係において操作量ＸＬに対する目標旋回速度ＶＲの傾きの絶対値を減少させる補正をし、目標速度演算部２５Ｂ１は、例えば目標駆動圧演算部２６Ｂによって演算された目標ブーム駆動圧が大きい程、目標速度テーブル２５ｂ１の関数関係において操作量ＸＲに対する目標ブーム速度ＶＢの傾きの絶対値を減少させる補正をした場合について説明したが、この場合に限るものではない。 Further, in the second embodiment of the present invention, the target speed calculation unit 25A1 is configured such that, for example, as the target turning drive pressure calculated by the target drive pressure calculation unit 26A increases, the target speed with respect to the operation amount XL in the functional relationship of the target speed table 25a1. For example, the target speed calculation unit 25B1 performs correction in the functional relationship of the target speed table 25b1 as the target boom driving pressure calculated by the target driving pressure calculation unit 26B increases. Although the case where correction for reducing the absolute value of the gradient of the target boom speed VB with respect to the amount XR has been described, the present invention is not limited to this case.
　例えば、本発明は、目標速度テーブル２５ａ１の関数関係において操作量ＸＬに対する目標旋回速度ＶＲの傾きの絶対値を減少させる減少量を設定し、目標速度テーブル２５ｂ１の関数関係において操作量ＸＲに対する目標ブーム速度ＶＢの傾きの絶対値を減少させる減少量を設定する減少量設定部を備えても良い。これにより、操作者が減少量設定部によって目標速度テーブル２５ａ１，２５ｂ１の各関数関係の補正の程度を自由に変更できるので、操作レバー１５Ａ，１５Ｂに対する操作者の操作感覚を調整でき、操作性能をより向上させることができる。 For example, the present invention sets a decrease amount that decreases the absolute value of the inclination of the target turning speed VR with respect to the operation amount XL in the functional relationship of the target speed table 25a1, and sets the target boom with respect to the operation amount XR in the functional relationship of the target speed table 25b1. You may provide the reduction amount setting part which sets the reduction amount which decreases the absolute value of the inclination of speed VB. As a result, the operator can freely change the degree of correction of each function relationship of the target speed tables 25a1 and 25b1 by the reduction amount setting unit, so that the operator's operation feeling with respect to the operation levers 15A and 15B can be adjusted, and the operation performance can be improved. It can be improved further.
　また、本発明は、目標速度演算部２５Ａ１，２５Ｂ１の関係補正部による目標速度テーブル２５ａ１，２５ｂ１の各関数関係の補正を有効又は無効にする切換部を備えても良い。これにより、操作者がこの切換部によって目標速度テーブル２５ａ１，２５ｂ１の各関数関係を無効にして設定を固定できるので、高い利便性を確保することができる。 In addition, the present invention may include a switching unit that enables or disables correction of each function relationship of the target speed tables 25a1 and 25b1 by the relationship correction unit of the target speed calculation units 25A1 and 25B1. Thereby, the operator can invalidate each function relationship of the target speed tables 25a1 and 25b1 by this switching unit and fix the setting, so that high convenience can be ensured.
　また、本発明の第１、第２実施形態では、電磁比例減圧弁１９Ａ１，１９Ｂ１は指令電流Ｉに対し設定圧ＰＳが反比例する特性を有する構成としたが、これに拘るものではない。例えば、図６（ａ）に示した電磁比例減圧弁１９Ａ１，１９Ｂ１のＤ位置とＥ位置とを入れ替えた弁構造とし、指令電流Ｉが増加するに従い開口量が増加し、設定圧ＰＳを増加させる構成としても良い。 In the first and second embodiments of the present invention, the electromagnetic proportional pressure reducing valves 19A1 and 19B1 are configured to have a characteristic in which the set pressure PS is inversely proportional to the command current I. However, the present invention is not limited to this. For example, a valve structure in which the D position and the E position of the electromagnetic proportional pressure reducing valves 19A1 and 19B1 shown in FIG. 6A are exchanged is used, and as the command current I increases, the opening amount increases and the set pressure PS increases. It is good also as a structure.
　１　油圧ショベル（作業機械）
　２　走行体
　３　旋回体
　３Ａ　旋回装置
　３ａ　旋回モータ
　４　フロント作業機
　４Ａ　ブーム
　４ａ　ブームシリンダ
　４Ｂ　アーム
　４ｂ　アームシリンダ
　４Ｃ　バケット
　４ｃ　バケットシリンダ
　１１　エンジン
　１１Ａ　エンジン回転数検出部
　１２　油圧ポンプ
　１２Ａ　傾転量調整部
　１３　作動油タンク
　１５Ａ　左操作レバー
　１５Ａ１，１５Ｂ１　操作量センサ（操作量検出部）
　１５Ｂ　右操作レバー
　１６Ａ，１６Ｂ，１６Ｃ，１６Ｄ　方向制御弁
　１７　吐出圧センサ（吐出圧検出部）
　１８Ａ，１８Ｂ，１８Ｃ，１８Ｄ　速度センサ（速度検出部）
　１９Ａ，１９Ｂ，１９Ｃ，１９Ｄ　流入制御部
　１９Ａ１，１９Ｂ１　電磁比例減圧弁（圧力制御弁）
　１９Ａ２，１９Ｂ２　電磁比例絞り弁（圧力制御弁）
　１９ａ１，１９ｂ１　ばね
　１９ａ２，１９ｂ２　電磁ソレノイド
　２０　コントローラ（油圧制御部）
　２１　リリーフ弁
　２５Ａ１，２５Ｂ１　目標速度演算部
　２５ａ１，２５ｂ１　目標速度テーブル
　２５ａ３，２５ｂ３　記憶部
　２５Ａ２，２５Ｂ２　圧力制限部
　２５ａ２，２５ｂ２　上限圧力テーブル
　２５ａ４，２５ｂ４　記憶部
　２６Ａ，２６Ｂ　目標駆動圧演算部
　２６Ａ１，２６Ｂ１　ＰＩＤ制御部
　２６Ａ２，２６Ｂ２　リミッタ処理部
　２７Ａ，２７Ｂ　差圧演算部
　２８Ａ，２８Ｂ　開口面積演算部
　３０　目標吐出量演算部
　３０Ａ　最大目標吐出圧選択部
　３０Ｂ　ＰＩＤ制御部
　３０Ｃ　目標吐出量補正部
　３５Ａ，３５Ｂ　関係補正部 1 Excavator (work machine)
DESCRIPTION OF SYMBOLS 2 Traveling body 3 Revolving body 3A Turning apparatus 3a Turning motor 4 Front work machine 4A Boom 4a Boom cylinder 4B Arm 4b Arm cylinder 4C Bucket 4c Bucket cylinder 11 Engine 11A Engine rotation speed detection part 12 Hydraulic pump 12A Tilt amount adjustment part 13 Actuation Oil tank 15A Left operation lever 15A1, 15B1 Operation amount sensor (operation amount detection unit)
15B Right control lever 16A, 16B, 16C, 16D Directional control valve 17 Discharge pressure sensor (discharge pressure detector)
18A, 18B, 18C, 18D Speed sensor (speed detector)
19A, 19B, 19C, 19D Inflow control part 19A1, 19B1 Electromagnetic proportional pressure reducing valve (pressure control valve)
19A2, 19B2 Electromagnetic proportional throttle valve (pressure control valve)
19a1, 19b1 Spring 19a2, 19b2 Electromagnetic solenoid 20 Controller (hydraulic control unit)
21 Relief valve 25A1, 25B1 Target speed calculation unit 25a1, 25b1 Target speed table 25a3, 25b3 Storage unit 25A2, 25B2 Pressure limiter 25a2, 25b2 Upper limit pressure table 25a4, 25b4 Storage unit 26A, 26B Target drive pressure calculation unit 26A1, 26B1 PID Control unit 26A2, 26B2 Limiter processing unit 27A, 27B Differential pressure calculation unit 28A, 28B Opening area calculation unit 30 Target discharge amount calculation unit 30A Maximum target discharge pressure selection unit 30B PID control unit 30C Target discharge amount correction unit 35A, 35B Relationship correction Part

Claims (8)

  1. 　原動機（１１）により駆動される油圧ポンプ（１２）と、この油圧ポンプ（１２）から吐出された作動油によって動作する複数の油圧アクチュエータ（３ａ，４ａ～４ｃ）と、これらの油圧アクチュエータ（３ａ，４ａ～４ｃ）を操作する操作装置（１５Ａ，１５Ｂ）とを備えた作業機械（１）に設けられ、
    　前記操作装置（１５Ａ，１５Ｂ）による操作入力を受けて前記油圧ポンプ（１２）から前記複数の油圧アクチュエータ（３ａ，４ａ～４ｃ）へ吐出される作動油の流量を制御する油圧制御部（２０）を備えた作業機械（１）の油圧制御装置において、
    　前記油圧ポンプ（１２）の吐出圧を検出する吐出圧検出部（１７）と、
    　前記複数の油圧アクチュエータ（３ａ，４ａ～４ｃ）の速度を検出する速度検出部（１８Ａ～１８Ｄ）と、
    　前記複数の油圧アクチュエータ（３ａ，４ａ～４ｃ）へ流入する作動油の圧力を制御する流入制御部（１９Ａ～１９Ｄ）と、
    　前記操作装置（１５Ａ，１５Ｂ）によって操作された操作量に基づいて、前記複数の油圧アクチュエータ（３ａ，４ａ～４ｃ）を動作させる速度の目標値を演算する目標速度演算部（２５Ａ１，２５Ｂ１）と、
    　前記速度検出部（１８Ａ～１８Ｄ）によって検出された前記速度及び前記目標速度演算部（２５Ａ１，２５Ｂ１）によって演算された前記目標値に基づいて、前記複数の油圧アクチュエータ（３ａ，４ａ～４ｃ）を駆動する駆動圧の目標値を演算する目標駆動圧演算部（２６Ａ，２６Ｂ）と、
    　前記吐出圧検出部（１７）によって検出された前記吐出圧及び前記目標駆動圧演算部（２６Ａ，２６Ｂ）によって演算された前記目標値に応じて、前記油圧ポンプ（１２）の吐出量の目標値を演算する目標吐出量演算部（３０）とを備え、
    　前記流入制御部（１９Ａ～１９Ｄ）は、前記目標駆動圧演算部（２６Ａ，２６Ｂ）によって演算された前記目標値に応じて、前記複数の油圧アクチュエータ（３ａ，４ａ～４ｃ）へ流入する作動油の圧力を制御すると共に、前記油圧制御部（２０）は、前記油圧ポンプ（１２）の前記吐出量を前記目標吐出量演算部（３０）によって演算された前記目標値に制御することを特徴とする作業機械（１）の油圧制御装置。     A hydraulic pump (12) driven by a prime mover (11), a plurality of hydraulic actuators (3a, 4a to 4c) operated by hydraulic oil discharged from the hydraulic pump (12), and these hydraulic actuators (3a, Provided in a work machine (1) provided with an operating device (15A, 15B) for operating 4a to 4c),
    A hydraulic control unit (20) for controlling the flow rate of hydraulic oil discharged from the hydraulic pump (12) to the plurality of hydraulic actuators (3a, 4a to 4c) in response to an operation input from the operating device (15A, 15B). In the hydraulic control device of the work machine (1) provided with
    A discharge pressure detector (17) for detecting the discharge pressure of the hydraulic pump (12);
    A speed detector (18A-18D) for detecting the speed of the plurality of hydraulic actuators (3a, 4a-4c);
    An inflow control unit (19A to 19D) for controlling the pressure of hydraulic oil flowing into the plurality of hydraulic actuators (3a, 4a to 4c);
    A target speed calculator (25A1, 25B1) for calculating a target value of speed for operating the plurality of hydraulic actuators (3a, 4a to 4c) based on the operation amount operated by the operating device (15A, 15B); ,
    Based on the speed detected by the speed detector (18A to 18D) and the target value calculated by the target speed calculator (25A1, 25B1), the plurality of hydraulic actuators (3a, 4a to 4c) are operated. A target drive pressure calculation unit (26A, 26B) for calculating a target value of the drive pressure to be driven;
    The target value of the discharge amount of the hydraulic pump (12) according to the discharge pressure detected by the discharge pressure detector (17) and the target value calculated by the target drive pressure calculator (26A, 26B). A target discharge amount calculation unit (30) for calculating
    The inflow control units (19A to 19D) are hydraulic fluids that flow into the plurality of hydraulic actuators (3a, 4a to 4c) according to the target values calculated by the target drive pressure calculation units (26A and 26B). And the hydraulic control unit (20) controls the discharge amount of the hydraulic pump (12) to the target value calculated by the target discharge amount calculation unit (30). Hydraulic control device for work machine (1)
  2. 　請求項１に記載の作業機械（１）の油圧制御装置において、
    　さらに、前記操作装置（１５Ａ，１５Ｂ）によって操作された前記操作量に基づいて、前記駆動圧の上限圧力を設定する圧力制限部（２５Ａ２，２５Ｂ２）を備え、
    　前記目標駆動圧演算部（２６Ａ，２６Ｂ）は、前記速度検出部（１８Ａ～１８Ｄ）によって検出された前記速度、前記目標速度演算部（２５Ａ１，２５Ｂ１）によって演算された前記目標値、及び前記圧力制限部（２５Ａ２，２５Ｂ２）によって設定された前記駆動圧の上限圧力に基づいて、前記駆動圧の目標値を演算することを特徴とする作業機械（１）の油圧制御装置。     In the hydraulic control device of the work machine (1) according to claim 1,
    Furthermore, a pressure limiting unit (25A2, 25B2) for setting an upper limit pressure of the driving pressure based on the operation amount operated by the operating device (15A, 15B),
    The target drive pressure calculation unit (26A, 26B) is configured to detect the speed detected by the speed detection unit (18A to 18D), the target value calculated by the target speed calculation unit (25A1, 25B1), and the pressure. The hydraulic control device for a work machine (1), wherein a target value of the driving pressure is calculated based on an upper limit pressure of the driving pressure set by a limiting unit (25A2, 25B2).
  3. 　請求項１に記載の作業機械（１）の油圧制御装置において、
    　前記目標駆動圧演算部（２６Ａ，２６Ｂ）は、演算した前記駆動圧の前記目標値よりも所定値だけ低い値を演算結果として前記目標吐出量演算部（３０）へ出力することを特徴とする作業機械（１）の油圧制御装置。     In the hydraulic control device of the work machine (1) according to claim 1,
    The target driving pressure calculation unit (26A, 26B) outputs a value lower than the target value of the calculated driving pressure by a predetermined value to the target discharge amount calculation unit (30) as a calculation result. Hydraulic control device of work machine (1).
  4. 　請求項１に記載の作業機械（１）の油圧制御装置において、
    　前記操作装置（１５Ａ，１５Ｂ）によって操作される前記操作量と前記目標速度演算部（２５Ａ１，２５Ｂ１）によって演算される前記目標値との関係（２５ａ１，２５ｂ１）が予め記憶された記憶部（２５ａ３，２５ｂ３）と、
    　この記憶部（２５ａ３，２５ｂ３）に記憶された関係（２５ａ１，２５ｂ１）を前記目標駆動圧演算部（２６Ａ，２６Ｂ）によって演算された前記目標値に応じて補正する関係補正部（３５Ａ，３５Ｂ）を備え、
    　前記目標速度演算部（２５Ａ１，２５Ｂ１）は、前記関係補正部（３５Ａ，３５Ｂ）によって補正された前記関係（２５ａ１，２５ｂ１）に対し、前記操作装置（１５Ａ，１５Ｂ）によって操作された前記操作量を適用して前記目標値を演算することを特徴とする作業機械（１）の油圧制御装置。     In the hydraulic control device of the work machine (1) according to claim 1,
    A storage unit (25a3) in which a relationship (25a1, 25b1) between the operation amount operated by the operation device (15A, 15B) and the target value calculated by the target speed calculation unit (25A1, 25B1) is stored in advance. 25b3) and
    A relationship correction unit (35A, 35B) that corrects the relationship (25a1, 25b1) stored in the storage unit (25a3, 25b3) according to the target value calculated by the target drive pressure calculation unit (26A, 26B). With
    The target speed calculation unit (25A1, 25B1) is operated by the operation device (15A, 15B) with respect to the relationship (25a1, 25b1) corrected by the relationship correction unit (35A, 35B). Is applied to calculate the target value. A hydraulic control device for a work machine (1).
  5. 　請求項１に記載の作業機械（１）の油圧制御装置において、
    　前記流入制御部（１９Ａ～１９Ｄ）は、前記油圧ポンプ（１２）と前記複数の油圧アクチュエータ（３ａ，４ａ～４ｃ）との間に設けられ、通過する作動油の圧力を制御する圧力制御弁（１９Ａ１，１９Ｂ１）を含み、
    　前記圧力制御弁（１９Ａ１，１９Ｂ１）は、外部からの入力信号を受信して駆動し、前記入力信号が増加するに従って開口量を減少させることを特徴とする作業機械（１）の油圧制御装置。     In the hydraulic control device of the work machine (1) according to claim 1,
    The inflow control sections (19A to 19D) are provided between the hydraulic pump (12) and the plurality of hydraulic actuators (3a, 4a to 4c), and are pressure control valves (control valves) that control the pressure of hydraulic fluid that passes through them. 19A1, 19B1)
    The hydraulic control device for a work machine (1), wherein the pressure control valves (19A1, 19B1) are driven by receiving an input signal from the outside and reduce an opening amount as the input signal increases.
  6. 　請求項２に記載の作業機械（１）の油圧制御装置において、
    　前記流入制御部（１９Ａ～１９Ｄ）は、前記油圧ポンプ（１２）と前記複数の油圧アクチュエータ（３ａ，４ａ～４ｃ）との間に設けられ、通過する作動油の圧力を制御する圧力制御弁（１９Ａ１，１９Ｂ１）を含み、
    　前記圧力制御弁（１９Ａ１，１９Ｂ１）は、外部からの入力信号を受信して駆動し、前記入力信号が増加するに従って開口量を減少させることを特徴とする作業機械（１）の油圧制御装置。     In the hydraulic control device of the work machine (1) according to claim 2,
    The inflow control sections (19A to 19D) are provided between the hydraulic pump (12) and the plurality of hydraulic actuators (3a, 4a to 4c), and are pressure control valves (control valves) that control the pressure of hydraulic fluid that passes through them. 19A1, 19B1)
    The hydraulic control device for a work machine (1), wherein the pressure control valves (19A1, 19B1) are driven by receiving an input signal from the outside and reduce an opening amount as the input signal increases.
  7. 　請求項３に記載の作業機械（１）の油圧制御装置において、
    　前記流入制御部（１９Ａ～１９Ｄ）は、前記油圧ポンプ（１２）と前記複数の油圧アクチュエータ（３ａ，４ａ～４ｃ）との間に設けられ、通過する作動油の圧力を制御する圧力制御弁（１９Ａ１，１９Ｂ１）を含み、
    　前記圧力制御弁（１９Ａ１，１９Ｂ１）は、外部からの入力信号を受信して駆動し、前記入力信号が増加するに従って開口量を減少させることを特徴とする作業機械（１）の油圧制御装置。     In the hydraulic control device of the work machine (1) according to claim 3,
    The inflow control sections (19A to 19D) are provided between the hydraulic pump (12) and the plurality of hydraulic actuators (3a, 4a to 4c), and are pressure control valves (control valves) that control the pressure of hydraulic fluid that passes through them. 19A1, 19B1)
    The hydraulic control device for a work machine (1), wherein the pressure control valves (19A1, 19B1) are driven by receiving an input signal from the outside and reduce an opening amount as the input signal increases.
  8. 　請求項４に記載の作業機械（１）の油圧制御装置において、
    　前記流入制御部（１９Ａ～１９Ｄ）は、前記油圧ポンプ（１２）と前記複数の油圧アクチュエータ（３ａ，４ａ～４ｃ）との間に設けられ、通過する作動油の圧力を制御する圧力制御弁（１９Ａ１，１９Ｂ１）を含み、
    　前記圧力制御弁（１９Ａ１，１９Ｂ１）は、外部からの入力信号を受信して駆動し、前記入力信号が増加するに従って開口量を減少させることを特徴とする作業機械（１）の油圧制御装置。     In the hydraulic control device of the work machine (1) according to claim 4,
    The inflow control sections (19A to 19D) are provided between the hydraulic pump (12) and the plurality of hydraulic actuators (3a, 4a to 4c), and are pressure control valves (control valves) that control the pressure of hydraulic fluid that passes through them. 19A1, 19B1)
    The hydraulic control device for a work machine (1), wherein the pressure control valves (19A1, 19B1) are driven by receiving an input signal from the outside and reduce an opening amount as the input signal increases.
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