WO2018151275A1 - 油圧機械の制御装置 - Google Patents
油圧機械の制御装置 Download PDFInfo
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- WO2018151275A1 WO2018151275A1 PCT/JP2018/005576 JP2018005576W WO2018151275A1 WO 2018151275 A1 WO2018151275 A1 WO 2018151275A1 JP 2018005576 W JP2018005576 W JP 2018005576W WO 2018151275 A1 WO2018151275 A1 WO 2018151275A1
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- hydraulic
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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
- E02F9/2203—Arrangements for controlling the attitude of actuators, e.g. speed, floating function
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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
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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
- E02F9/2225—Control of flow rate; Load sensing arrangements using pressure-compensating valves
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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
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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
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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
- E02F9/2264—Arrangements or adaptations of elements for hydraulic drives
- E02F9/2271—Actuators and supports therefor and protection therefor
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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
- E02F9/2278—Hydraulic circuits
- E02F9/2296—Systems with a variable displacement pump
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- 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
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- 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
- F15B11/02—Systems essentially incorporating special features for controlling the speed or actuating force of an output member
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- 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
- F15B11/02—Systems essentially incorporating special features for controlling the speed or actuating force of an output member
- F15B11/028—Systems essentially incorporating special features for controlling the speed or actuating force of an output member for controlling the actuating force
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- 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
- F15B11/02—Systems essentially incorporating special features for controlling the speed or actuating force of an output member
- F15B11/04—Systems essentially incorporating special features for controlling the speed or actuating force of an output member for controlling the speed
- F15B11/042—Systems essentially incorporating special features for controlling the speed or actuating force of an output member for controlling the speed by means in the feed line, i.e. "meter in"
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- 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
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- 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
- F15B11/161—Servomotor systems without provision for follow-up action; Circuits therefor with two or more servomotors with sensing of servomotor demand or load
- F15B11/165—Servomotor systems without provision for follow-up action; Circuits therefor with two or more servomotors with sensing of servomotor demand or load for adjusting the pump output or bypass in response to demand
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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
- E02F9/2253—Controlling the travelling speed of vehicles, e.g. adjusting travelling speed according to implement loads, control of hydrostatic transmission
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- 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
- F15B2211/20553—Type of pump variable capacity with pilot circuit, e.g. for controlling a swash plate
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- 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
- F15B2211/65—Methods of control of the load sensing pressure
- F15B2211/654—Methods of control of the load sensing pressure the load sensing pressure being lower than the load pressure
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- 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
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- 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
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- 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
- F15B2211/6658—Control using different modes, e.g. four-quadrant-operation, working mode and transportation mode
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- 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
- F15B2211/70—Output members, e.g. hydraulic motors or cylinders or control therefor
- F15B2211/705—Output members, e.g. hydraulic motors or cylinders or control therefor characterised by the type of output members or actuators
- F15B2211/7051—Linear output members
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- 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
- F15B2211/70—Output members, e.g. hydraulic motors or cylinders or control therefor
- F15B2211/705—Output members, e.g. hydraulic motors or cylinders or control therefor characterised by the type of output members or actuators
- F15B2211/7058—Rotary output members
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- 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
- F15B2211/70—Output members, e.g. hydraulic motors or cylinders or control therefor
- F15B2211/71—Multiple output members, e.g. multiple hydraulic motors or cylinders
- F15B2211/7135—Combinations of output members of different types, e.g. single-acting cylinders with rotary motors
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- 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
- F15B2211/70—Output members, e.g. hydraulic motors or cylinders or control therefor
- F15B2211/76—Control of force or torque of the output member
- F15B2211/763—Control of torque of the output member by means of a variable capacity motor, i.e. by a secondary control on the motor
Definitions
- the present invention relates to a control device used in a hydraulic oil supply system for a hydraulic actuator for driving a hydraulic machine such as an excavation turning work machine.
- Patent Documents 1 and 2 a hydraulic oil supply system for a hydraulic actuator for driving a hydraulic machine such as an excavation turning work machine, which is a variable displacement type via a direction control valve It is known that hydraulic fluid discharged from the hydraulic pump is configured to be supplied to a hydraulic actuator.
- the discharge flow rate control mechanism of the variable displacement hydraulic pump uses a load sensing valve, the discharge pressure of the hydraulic pump, and the secondary side of the direction control valve (the inlet of the hydraulic actuator).
- the discharge flow rate of the hydraulic pump is adjusted so that the difference from the load pressure on the port side (hereinafter simply referred to as “differential pressure”) is constant.
- the opening area of the meter-in restrictor that restricts the flow path to the hydraulic actuator is changed according to the operation amount of the manual operation tool.
- the hydraulic actuator is supplied from the directional control valve with the required amount of hydraulic oil corresponding to the operating speed of the actuator set by the manual operating tool, that is, approximately the same amount as the required flow rate of the actuator. Since the flow rate can be realized, the operating efficiency of the hydraulic oil supply system can be increased.
- Patent Documents 1 and 2 disclose a technique that enables adjustment of a target differential pressure set by a load sensing valve. That is, the control pressure adjustable by the controller is added to the discharge pressure of the hydraulic pump against the load pressure in the load sensing valve.
- Patent Document 2 in a conventional excavation and turning work machine, a pair of traveling devices such as a pair of left and right crawler traveling devices are driven individually in the plurality of hydraulic actuators. A pair of traveling hydraulic motors is provided.
- Patent Document 2 when only the traveling hydraulic motor is driven among the hydraulic actuators, that is, when it is detected that the vehicle is set to travel, the target differential pressure in the load sensing valve is decreased.
- a technique for reducing the discharge amount of the hydraulic pump has been disclosed, which enables a hydraulic pump for driving a traveling hydraulic motor with a low load pressure required as compared with other hydraulic actuators for work to be performed. The loss of the discharge amount is reduced, and the operation efficiency of the hydraulic actuator is increased.
- a traveling hydraulic motor having a movable swash plate as a capacity changing means, which is movable at two positions, a high speed position with a small tilt angle and a low speed position with a large tilt angle.
- a configuration in which the tilt angle of the plate can be switched is known. Assuming that the discharge flow rate from the hydraulic pump is constant, when the movable swash plate is moved to the high speed position, the hydraulic motor is reduced in capacity and rotated at a high speed, and when the movable swash plate is moved to the low speed position, the hydraulic motor The capacity increases and is driven to rotate at a low speed.
- the switching of the movable swash plate position of the hydraulic pump is performed by manual operation of a lever or the like provided in the vicinity of the driver's seat of the vehicle in the above-mentioned Patent Document 3.
- the vehicle can be driven on the road.
- the vehicle is moved to a low speed when it is desired to run at a low speed while working.
- JP-A-2-76904 JP 2011-247301 A Japanese Patent Laid-Open No. 10-338947
- the movable swash plate of the traveling hydraulic motor is set to a high speed position (small capacity setting position).
- high-speed setting state There is a great demand for a higher traveling speed of the vehicle (hereinafter referred to as “high-speed setting state”).
- the traveling speed of the vehicle when the movable swash plate of the traveling hydraulic motor is set to the low speed position (hereinafter referred to as “low speed setting state”) is the same as the conventional traveling speed in order to maintain reliable work accuracy. It will be good.
- Patent Document 3 when the low speed setting state is set, the traveling speed is lowered by reducing the maximum discharge flow rate of the variable displacement hydraulic pump.
- this technique simply reduces the maximum tilt angle position of the hydraulic pump by a fixed angle in accordance with the switching to the large capacity setting position of the traveling hydraulic motor.
- the flow rate that flows from the hydraulic pump to the hydraulic actuator is adjusted according to the amount of manual operation, provided that the amount of operation is not affected by the reduction in the maximum discharge flow rate.
- the operation amount reaches the area corresponding to the reduction of the maximum discharge flow rate, even if the manual operation amount is increased from there to the maximum operation amount, the flow rate to the actuator is saturated and cannot be adjusted. There can be a situation where the performance is significantly reduced.
- the hydraulic motor is changed to one that changes the configuration of the two-stage switching type capacity changing means such as a movable swash plate (the speed ratio is changed), the mechanical design change can be made, although it can meet the above demands. This is disadvantageous in terms of parts sharing and the like, leading to high costs.
- the invention according to the present application uses the following means in order to solve the problems as described above.
- control device is a control device for a hydraulic machine including a plurality of hydraulic actuators driven by oil discharged from a variable displacement hydraulic pump driven by an engine, and driving each hydraulic actuator.
- the flow rate of the discharge oil of the hydraulic pump is controlled so as to satisfy the required flow rate of the hydraulic actuator, and the target value of the ratio of the supply flow rate to the required flow rate of each hydraulic actuator is set according to the change of the engine speed. It is configured to correct.
- the plurality of hydraulic actuators include a hydraulic motor for running the hydraulic machine, the capacity of which can be switched to at least two different capacities. In addition to the change in the number, the target value of the ratio of the supply flow rate to the required flow rate of each hydraulic actuator is corrected in accordance with the switching of the capacity of the hydraulic motor.
- the plurality of hydraulic actuators are supplied with discharge oil from the hydraulic pump via meter-in throttles of directional control valves provided separately,
- the required flow rate of the actuator is defined by the opening of the meter-in throttle of each directional control valve.
- the control device sets a common target value for all actuators for the differential pressure between the discharge pressure of the discharge oil of the hydraulic pump and the load pressure of the supply oil to each hydraulic actuator.
- the actuator is configured to control the flow rate of the oil discharged from the hydraulic pump so as to achieve the target value of the differential pressure.
- the actuator responds to changes in the engine speed.
- the correction of the target value of the ratio and the correction of the target value of the ratio according to the switching of the capacity of the hydraulic motor are performed.
- control device generates a control pressure for changing the target value of the differential pressure as a secondary pressure of an electromagnetic proportional valve
- a plurality of maps are stored as correlation maps of control output values as current values applied to the electromagnetic proportional valve.
- the plurality of maps include two or more maps respectively corresponding to the at least two stages of capacity settings of the hydraulic motor.
- the two or more maps include a first map corresponding to a small capacity setting of the hydraulic motor and a second map corresponding to a large capacity setting of the hydraulic motor. Including.
- the control device discharges the hydraulic pump using the second map only when it is confirmed that the hydraulic motor is actually driven when the large capacity of the hydraulic motor is set.
- the flow rate control of the oil is performed, and otherwise, the flow rate control of the discharge oil of the hydraulic pump using the first map is performed.
- the ratio (speed ratio) between the output speed when the large capacity is set and the output speed when the small capacity is set can be changed. That is, the output speed difference accompanying the switching of the capacity is defined by the standard of the hydraulic motor, assuming that the operation amount of the directional control valve for the hydraulic motor is constant at a constant engine speed. The value can be different from the value.
- the high idle rotation speed (maximum engine rotation speed) increases, so that the traveling hydraulic motor
- the road running speed can be increased by high-speed engine rotation.
- the large capacity is set, the work is not affected by the increase in the high idle speed due to the high engine speed.
- the output speed of the hydraulic motor can be kept low so that the conventional traveling speed is easy.
- the speed ratio can be changed by changing the setting position of the movable swash plate of the hydraulic motor. In this case, however, it is necessary to change the design of the complicated mechanism for positioning the movable swash plate. May lead to However, as described in the first aspect, the control device according to the present application corrects the target value of the differential pressure between the discharge pressure and the load pressure, and the existing load sensing pump control system. It is only necessary to adopt the structure adopted in the case of switching the capacity of the hydraulic motor for traveling. For example, as described in the second aspect, it is sufficient to store two or more maps corresponding to each capacity setting of the hydraulic motor. Therefore, it is possible to provide a control device that exhibits the above-described effects at low cost.
- the correction of the target value of the differential pressure controls the flow rate of the oil discharged from the hydraulic pump, so the correction of the ratio of the supply flow rate to the required flow rate is applied not only to the traveling hydraulic motor but also to all actuators. Will be.
- the output speed of the traveling hydraulic motor is set low when the large capacity is set, not only the traveling speed can be suppressed, but also the driving speed of other actuators can be reduced. Along with switching to the large capacity setting, the driving speed is lowered, and the working efficiency is lowered.
- FIG. 1 is a block diagram of a load-sensitive pump control system.
- FIG. 5A is a map of control output values
- FIG. 5B is a graph of control pressure
- FIG. 5C is a graph of target differential pressure.
- FIG. 1 is a block diagram of a load-sensitive pump control system.
- FIG. 5A is a map of control output values
- FIG. 5B is a graph of control pressure
- FIG. 5C is a graph of target differential pressure.
- FIG. 8 (a) is a map of control output values
- FIG. 8 (b) is a graph of control pressure
- FIG. 8 (c). ) Is a graph of target differential pressure.
- the excavation turning work machine 10 includes a pair of left and right crawler type traveling devices 11.
- Each crawler type traveling device 11 supports a driving sprocket 11b and a driven sprocket 11c on a track frame 11a, and a crawler 11d is wound between the driving sprocket 11b and the driven sprocket 11c.
- the traveling device is a wheel-type traveling device.
- a swivel base 12 On the upper part of the pair of left and right crawler type traveling devices 11, a swivel base 12 is mounted so as to be rotatable around a vertical axis with respect to both the crawler type traveling devices 11, and the engine E and the pump unit PU are mounted on the swivel base 12.
- the bonnet 13 that houses the control valve unit V and the like is mounted.
- an operator seat 14 is arranged on the swivel base 12, and manual operation tools such as levers and pedals for operating each hydraulic actuator described later are arranged in front of and on the side of the seat 14. Yes.
- a boom bracket 15 is provided on the swivel base 12 so as to be pivotable in the horizontal direction with respect to the swivel base 12, and a base end portion of the boom 16 is pivotally supported by the boom bracket 15 so as to be pivotable up and down.
- a base end portion of the arm 17 is pivotally supported at the distal end portion so as to be rotatable up and down, and a bucket 18 as a work machine is pivotally supported at the distal end portion of the arm 17 so as to be rotatable up and down.
- a pair of left and right crawler type traveling devices 11 is attached with a blade 19 for earth removal so as to be rotatable up and down.
- FIG. 1 shows a boom cylinder 20, an arm cylinder 21, and a bucket cylinder 22 that are typical hydraulic actuators.
- the boom 16 rotates up and down with respect to the boom bracket 15 by the expansion and contraction of the piston rod of the boom cylinder 20, and the arm 17 rotates up and down with respect to the boom 16 by the expansion and contraction of the piston rod of the arm cylinder 21.
- the bucket 18 is configured to rotate up and down with respect to the arm 17 by the expansion and contraction of the rod.
- the excavation turning work machine 10 includes a swing cylinder for horizontally turning the boom bracket 15 with respect to the turntable 12, which is not shown in FIG.
- a blade cylinder for rotating the blade 19 up and down with respect to the crawler type traveling device 11 is provided.
- the excavating and turning work machine 10 is a first traveling for driving one drive sprocket 11b of the left and right crawler traveling devices 11, which is not shown in FIG. 1, as a rotary hydraulic actuator composed of a hydraulic motor.
- a motor 23 (see FIG. 2)
- a second traveling motor 24 (see FIG. 2) for driving the other drive sprocket 11b of the left and right crawler traveling devices 11, and a crawler traveling device 12 on the left and right crawler traveling devices 11 is provided with a turning motor 25 (see FIG. 2).
- the excavation turning work machine 10 is provided with a hydraulic pump 1 driven by an engine E.
- the hydraulic pump 1 supplies pressure oil to the boom cylinder 20, the arm cylinder 21, the travel motors 23 and 24, and the turning motor 25.
- these are shown as typical hydraulic actuators, and other hydraulic actuators are not shown.
- Each hydraulic actuator is provided with a separate directional control valve, and these directional control valves are combined to form the control valve unit V.
- each directional control valve is switched by manual operation of each of the aforementioned manual operation tools, and the oil supply direction is switched. Furthermore, each directional control valve is provided with a meter-in throttle, and the opening degree of the meter-in throttle changes according to the operation amount of each manual operation tool.
- the supply flow rate of the hydraulic oil to each hydraulic actuator can be matched with the required flow rate of each hydraulic actuator, and work can be performed. It is possible to reduce the surplus flow rate that is returned to the tank without any loss and to improve the operating efficiency of the hydraulic oil supply system to the hydraulic actuator.
- the required flow rate is determined by the opening of the meter-in throttle that is set corresponding to the operation amount of the direction control valve.
- the boom operation lever 30a As the manual operation tools for the direction control valves 30, 31, 33, 34, and 35, the boom operation lever 30a, the arm operation lever 31a, the first travel operation lever 33a, the second travel operation lever 34a, and the turn
- these manual operation tools may be a pedal, a switch, or the like in addition to the lever, and may be integrated as appropriate.
- one direction control valve may be controlled by rotation of one lever in one direction
- another direction control valve may be controlled by rotation in the other direction.
- the manual operation tool (lever 30a, 31a, 33a, 34a, 35a) is a remote control (pilot) valve, and each direction control valve 30, 31, 33, 34, 35 is controlled by the pilot pressure generated by the operation of the manual operation tool. It may be controlled.
- the excavation turning work machine 10 is provided with a shift switch 26.
- the shift switch 26 is linked to the movable swash plate 23a of the first traveling motor 23 and the movable swash plate 24a of the second traveling motor 24, which are variable displacement hydraulic motors. 23a and 24a are tilted simultaneously.
- the movable swash plates 23a and 24a of the travel motors 23 and 24 may be operated with a manual operation tool other than a switch, such as a pedal or a lever.
- the speed change switch 26 is an ON / OFF changeover switch, and when the speed change switch 26 is turned ON, the movable swash plates 23a and 24a are tilted at a small tilt angle for setting a high speed (normal speed) suitable for traveling on the road.
- the shift switch 26 is turned OFF, the movable swash plates 23a and 24a are arranged at a large tilt angle (large capacity) position for setting a low speed (working speed) suitable for work travel. It is supposed to be.
- the movable swash plates 23a and 24a are linked to piston rods of swash plate control cylinders 23b and 24b, which are hydraulic actuators, and are opened and closed to supply hydraulic oil to both swash plate control cylinders 23b and 24b.
- a valve 27 is provided. When the shift switch 26 is turned on, the on-off valve 27 is opened by the pilot pressure to supply hydraulic oil to the swash plate control cylinders 23b and 24b, and the swash plate control cylinders 23b and 24b move the movable swash plates 23a and 24a to a small tilt angle position. Push.
- the on-off valve 27 returns the hydraulic oil from the swash plate control cylinders 23b and 24b, and the movable swash plates 23a and 24a are returned to the large tilt angle position by the spring bias of the piston rod.
- the pump unit PU is configured by combining the hydraulic pump 1, the relief valve 3 that prevents the discharge pressure of the hydraulic pump 1 from becoming excessive, and the load-sensing pump control system 5.
- the load-sensing pump control system 5 is a combination of a pump actuator 6, a load sensing valve 7, and a pump control proportional valve 8.
- the pump actuator 6 is composed of a hydraulic cylinder, and its piston rod 6a is linked to the movable swash plate 1a of the first hydraulic pump 1, and the movable swash plate 1a is simultaneously tilted by the expansion and contraction of the piston rod 6a. Change the tilt angle. Thus, changing the discharge flow rate Q P of the hydraulic pump 1.
- the supply / discharge port of the load sensing valve 7 communicates with the pressure oil chamber 6b of the pump swash plate actuator 6 for extending the piston rod.
- the load sensing valve 7 is urged by a spring 7a in a direction of removing oil from the pressure oil chamber 6b of the pump swash plate actuator 6, that is, a direction of contracting the piston rod 6a.
- the contraction direction of the piston rod 6a is on the inclination angle increasing side of the movable swash plate 1a, that is, the discharge flow rate increasing side of the hydraulic pump 1.
- a part of the oil discharged from the hydraulic pump 1 is introduced into the load sensing valve 7 as hydraulic oil supplied to the pressure oil chamber 6 b of the pump swash plate actuator 6.
- the discharge pressure P P as the pilot pressure to the load sensing valve 7 switches the load sensing valve 7 in the direction of supplying oil to the pressure oil chamber 6b of the pump swash plate actuator 6, that is, in the direction of extending the piston rod 6a. Act on.
- the maximum hydraulic pressure that is, the maximum load
- the maximum hydraulic pressure out of all the hydraulic pressures on the secondary side through the meter-in throttle, that is, all the hydraulic oil supplied from each directional control valve to each hydraulic actuator. extracting pressure P L, is added to the load sensing valve 7 as a pilot pressure against it to discharge pressure P P.
- the pressure difference [Delta] P (uncontrolled differential pressure [Delta] P 0 between the discharge pressure P P and the maximum load pressure P L ) Is switched depending on whether the spring force F S of the spring 7a is higher or lower. That is, the pressure difference ⁇ P is exceeds the spring force F S, the piston rod 6a of the pump actuator 6 is extended, reducing the tilt angle of the movable swash plate 1a, to reduce the discharge flow rate Q P of the hydraulic pump 1.
- the piston rod 6a of the pump actuator 6 is contracted to increase the tilt angle of the movable swash plate 1a, increasing the discharge flow rate Q P of the hydraulic pump 1.
- the required flow rate Q R is proportional to the meter-in throttle opening degree A (cross section).
- the opening A of the meter-in throttle is determined according to the operation amount of the manual operation tool of the direction control valve. That is, the required flow rate Q R is the amount determined regardless of changes in engine speed, long as it retains the operation amount constant, the required flow rate Q R is kept constant.
- the supply flow rate through the meter aperture in the directional control valve to the hydraulic actuator to be operated if insufficient to the required flow rate Q R of the hydraulic actuator, the difference pressure ⁇ P is reduced by less than the spring force F S, the load sensing valve 7 operates in a direction to increase the inclination angle of the movable swash plate 1a, increasing the discharge flow rate Q P of the hydraulic pump 1, the hydraulic Increase the supply flow rate to the actuator.
- the drive speed of the hydraulic actuator can be increased to the speed set by the manual operation tool.
- each lever operation amount spool stroke of each directional control valve
- the opening of the meter-in throttle of each directional control valve is maximum
- the required flow rate of the boom cylinder 20 for rotating the boom 16 is high, while the required flow rate of the turning motor 25 for rotating the swivel base 12 is not so high.
- the hydraulic pump 1 supplies oil at a flow rate that matches the required flow rate defined by each directional control valve. That is, for all actuators, the required flow rate Q ratio of the supply flow rate Q with respect to R (Q / Q R) (hereinafter referred to as "test main flow ratio”) (hereinafter the goal of is 1, the target value " The target required flow rate ratio Rq ”) and the tilt angle (pump capacity) of the movable swash plate 1a of the hydraulic pump 1 are controlled.
- the target differential pressure ⁇ P in the load sensing valve 7 is the specified differential pressure ⁇ P 0 defined by the spring force F S irrespective of the change in the engine speed (that is, in the entire engine speed range).
- the amount of operation of the boom operating lever 30a is set on the assumption that the movable swash plate 1a of the pump 1 is controlled).
- a supply flow rate characteristic in the case where the turning of the boom 16 at the maximum and the turning of the turntable 12 at the maximum operation amount of the turning operation lever 35a are alternately performed will be considered with reference to FIG.
- FIG. 4 shows characteristics of the supply flow rate Q of the hydraulic actuator over the entire region of the engine speed N set for the operation of the hydraulic actuator (here, the supply flow rate Qb to the boom cylinder 20 and the supply flow rate of the swing cylinder 23).
- Qs characteristics the region of the engine speed N is such that the low idle speed NL is the minimum value and the high idle speed NH is the maximum value.
- the case where the engine is operated when the engine is driven (hereinafter referred to as “low idle rotation”) is denoted as ⁇ NL .
- the supply flow rate Q is a flow rate that is actually supplied to each actuator via the directional control valve.
- the required flow rate Qb R of the boom cylinder 20 when the operation amount of the boom operation lever 30a is maximized is determined by the maximum opening area S MAX of the meter-in throttle of the direction control valve 30 (see FIG. 7). Since the required flow rate Qb R is smaller than the pump maximum discharge flow rate Q PHMAX during high idle rotation, the tilt angle ⁇ b1 of the movable swash plate 1a when the boom 16 is driven during high idle rotation is equal to or less than the maximum tilt angle ⁇ MAX . Yes (in this embodiment, it is smaller than the tilt angle ⁇ MAX ). That is, during high idle rotation, the supply flow rate Qb to the boom cylinder 20 is the same Qb R as the required flow rate. That is, during the high idle rotation, the supply flow rate Qb to the boom cylinder 20 becomes the maximum value, and the drive speed of the boom 16 at this time becomes the maximum drive speed.
- the required flow rate Qb R is, because they are high among all actuators, engine
- the maximum discharge flow rate Q PMAX decreases as the number N decreases from the high idle rotation speed N H
- the maximum discharge flow rate Q PMAX itself becomes the boom cylinder (at the time when the engine rotation speed N becomes N 1 in FIG. 4). It becomes equal to the required flow rate Qb R 20.
- the maximum discharge flow rate Q PMAX falls below the required flow rate Qb R of the boom cylinder 20, resulting in a decrease in engine speed. Accordingly, the supply flow rate Qb to the boom cylinder 20 is overlapped with the maximum discharge flow rate Q PMAX and is reduced. As the supply flow rate Qb decreases, the operating speed of the boom cylinder 20, that is, the driving speed of the boom 16 decreases.
- the required flow rate Qs R of the swing motor 25 when the operation amount of the swing operation lever 35a is maximized is determined by the maximum opening area S MAX of the meter-in throttle of the direction control valve 35 (see FIG. 7).
- the movable swash plate 1a of the hydraulic pump 1 is arranged at the tilt angle ⁇ s1, and the swing cylinder 23 is operated at the maximum speed, that is, the swivel base 12 is rotated at the maximum speed. . Therefore, during high idle rotation, the boom cylinder 20 driving with the maximum operation amount of the boom operation lever 30a and the turning motor 25 driving with the maximum operation amount of the turning operation lever 35a are alternately performed. Both the boom 16 and the swivel base 12 rotate at their maximum drive speeds.
- the required flow rate Qs R of the swing cylinder 23 with the maximum operation amount of the swing operation lever 35a is considerably lower than the required flow rate Qb R of the boom cylinder 20 with the maximum operation amount of the boom operation lever 30a.
- the tilt angle ⁇ H of the movable swash plate 1a is considerably smaller than the tilt angle ⁇ b1 when the boom cylinder 20 is operated with the boom operation lever 30a as the maximum operation amount, and the maximum tilt angle ⁇ MAX. Has a considerable tilt tolerance.
- the tilt angle ⁇ of the movable swash plate 1a is tilted toward the angle increase side so that the supply flow rate Qs satisfies the required flow rate Qs R.
- this tilt allowable width is large, the engine speed N is low idle rotation. reduced to a few N L, even in a state where the movable swash plate 1a has reached the slant angle ⁇ s2 is tilted at an angle increasing side maximally still does not lead to a maximum tilting angle theta MAX.
- the driving speed of the boom 16 during the low idle rotation is lower than that during the high idle rotation
- the driving speed during the low idle rotation of the swivel base 12 is maintained at the high idle rotation.
- the operator turns the boom 16 at a slow speed assumed by driving the engine E at the low idle rotation speed N L , and then continues to turn the turntable 12.
- the rotation speed is faster than expected and the work is difficult.
- the speed of the swivel base 12 does not change when the engine speed is reduced. Therefore, the speed can be adjusted only by adjusting the swivel operation lever 35a. This makes it difficult to perform fine turning operations.
- the rotation of the boom 16 and the rotation of the swivel base 12 are alternately performed as described above, the rotation of the boom 16 is slower than that during the high idle rotation during the low idle rotation.
- the rotation of the turntable 12 can be slowed, and the problem that the turn of the turntable 12 is felt faster relative to the rotation of the boom 16 can be solved.
- the load sensing pump control system 5 is provided with an electromagnetic proportional valve as the pump control proportional valve 8.
- the oil from the pump control proportional valve 8 is supplied to the load sensing valve 7 as pilot pressure oil. Secondary pressure of the load sensing valve 7 having of this oil is the control pressure P C to be added to the load sensing valve 7 to resist the maximum load pressure P L.
- Min plus control pressure P C the differential pressure between the discharge pressure P P and the maximum load pressure P L required to balance the spring force F S, ie, the target differential pressure ⁇ P is reduced.
- the load sensing valve 7 as increasing the control pressure P C acts on the slant angle decreasing side of the movable swash plate 1a, reducing the delivery rate of the hydraulic pump 1.
- the control pressure P C is determined by the current value applied to the solenoid 8a of the pump control proportional valve 8 is an electromagnetic proportional valve. This is the control output value C. Therefore, for each directional control valve of each hydraulic actuator, a correlation of the required flow rate of the hydraulic actuator with respect to the operation amount of the manual operating tool is assumed for each engine speed, and the engine speed is thus realized so as to realize the assumed correlation.
- a correlation map of the control output value C corresponding to is prepared, and this map is stored in the storage unit of the controller that controls the control output value for the pump control proportional valve 8, so that the engine speed is as described above.
- the excavation turning work machine 10 is configured with a hydraulic actuator control system as shown in FIG. First, a correlation map M of the control output value C corresponding to the engine speed N for all actuators is stored in the storage unit 51 provided in the controller 50.
- a correlation map M of the control output value C with respect to the engine speed N stored in the storage unit 51 is prepared for each work mode that can be set in the excavation turning work machine 10.
- the excavation turning work machine 10 may be configured to be able to set a fuel saving mode or the like that lowers the high idle rotation speed than in a normal case, and a map of the control output value C that is used when this is set, It may be included in the aforementioned map group.
- the controller 50 receives an engine speed detection signal from the engine speed detection unit 52 and an ON / OFF signal of the shift switch 26. Further, a travel detection signal indicating whether or not the excavation turning work machine 10 is actually traveling (that is, whether or not the travel motors 23 and 24 are being driven) is sent to the controller 50 from the travel detection means 53. Entered.
- the travel detection means 53 may be configured to detect the operation amount of the travel operation levers 33a and 34a (for example, it is determined that the vehicle is not traveling when the operation amount of both the levers 33a and 34a is 0).
- the ON / OFF signal of the speed change switch 26 and the travel detection signal from the travel detection means 53 are related to whether the standard map M1 is selected or the low speed travel map M2 is selected. In connection with selection of the map for the fuel saving mode, it is conceivable that a signal or the like from a switch that is turned ON when the fuel saving mode is set is input to the controller 50.
- the controller 50 determines the setting mode, and selects a map corresponding to the setting mode from the correlation map group of the control output value C with respect to the engine speed N stored in the storage unit 51. Then, the target value of the control output value C is determined by applying the engine speed N based on the input signal from the engine speed detector 52 to the selected map.
- the controller 50 adds the current of the determined control output value C to the solenoid 8a of the pump control proportional valve 8 in the load sensing type pump control system 5, and from the pump control proportional valve 8 to the load sensing valve 7. supplies the pilot pressure oil having a control pressure P C generated by the addition of the control output value C, thereby, via a pump actuator 6, the tilt angle of the movable swash plate 1a of the hydraulic pump 1, i.e., The discharge flow rate of the hydraulic pump 1 is controlled.
- FIG. 5A shows a standard map M1 showing a change in the control output value C as the engine speed N is decreased from the high idle speed NH to the low idle speed NL .
- the configuration of a representative standard map M1 in the map group prepared for each of several modes that can be set in the excavation turning work machine 10 as described above will be described.
- the standard map M1 sets the control output value C at the time of high idle rotation to the minimum value C 0 (the value at which the secondary pressure (control pressure P C ) of the pump control proportional valve 8 is 0), and the control output at the time of low idle rotation.
- the value C is the maximum value C MAX, and the control output value C is increased as the engine speed N is decreased from the high idle speed NH to the low idle speed NL .
- the control output value C of the pump control proportional valve 8 (current applied to the solenoid 8a) is changed in accordance with the change in the engine speed N based on the standard map M1.
- the control pressure P C is zero. Therefore, the target differential pressure ⁇ P is a specified differential pressure ⁇ P 0 equal to the spring force F S of the load sensing valve 7.
- the control pressure P C is increased, correspondingly, the target differential pressure ⁇ P is reduced.
- the target differential pressure ⁇ P during the low idle rotation is set as the minimum target differential pressure ⁇ P MIN .
- FIG. 6 is a diagram showing the effect of “deceleration control” appearing in the supply flow rate characteristic to the hydraulic actuator corresponding to the change in the engine speed, and shows two hydraulic actuators (here, boom cylinders) having different required flow rates. 20 and the turning motor 25), and a graph of the pump supply flow rate Qb when driving the boom cylinder 20 having a high required flow rate, and a request.
- the graph of the supply flow rate Qs in the case of driving the turning motor 25 with a low flow rate is shown.
- a graph of the maximum discharge flow rate Q PMAX is drawn as in FIG.
- Each of the operation levers 30a and 35a has the maximum operation amount (the spool stroke S of each direction control valve 30 and 35 is the maximum value S MAX ), that is, the respective required flow rates Qb R and Qs R. Is the maximum.
- the tilt angle of the movable swash plate 1a is set to ⁇ NH for high idle rotation and ⁇ NL for low idle rotation.
- target differential pressure [Delta] P is defined differential pressure [Delta] P 0 - become a control pressure [Delta] P C, decreases than at high idle speed.
- the target required flow rate ratio Rq of each actuator is set to a value smaller than the target value 1 at the time of high idle rotation.
- RqL N L / N H.
- the tilt angle ⁇ NL of the movable swash plate 1 a is suppressed to ⁇ b 2, and the rotation supply flow rate Qb L is reduced to Qb R ⁇ N L / N H while the swing motor 25 is driven.
- the tilt angle ⁇ NL of the movable swash plate 1a can be tilted to ⁇ s2 without deceleration control, but is suppressed to ⁇ s3 smaller than that, and the supply flow rate Qs L is reduced to Qs R ⁇ N L / N H.
- the supply flow rate Q decreases at the same ratio, and the respective drive speeds are also the same. Decreases in proportion.
- the target required flow rate ratio Rq at the time of driving each actuator is set to N M / N H.
- the arbitrary engine speed NM is a numerical value that becomes smaller as it approaches the low idle speed NL . Therefore, the target required flow rate when each actuator is driven as the engine speed N decreases toward the low idle speed NL. The ratio Rq is reduced.
- the target required flow rate ratio Rq corresponding to the arbitrary engine speed N M is set to N M / N H because the supply flow rate Q is reduced when each actuator is driven as the target engine speed N decreases. Is an example for adjusting to a decrease in engine speed, and may be a numerical value different from this. What is important is that the target required flow rate ratio Rq decreases as the target engine speed N decreases from the high idle speed NH, and the engine speed decreases for each actuator when each actuator is operated. In addition, an effect of reducing the target required flow rate ratio Rq can be obtained.
- the target differential pressure ⁇ P is not changed regardless of the change in the engine speed.
- the supply flow rate Qs satisfies the required flow rate Qs R over the entire engine speed N from the high idle speed NH to the low idle speed NL.
- the reduction effect of the target required flow rate ratio Rq by increasing the control output value C shown in FIG. 5A with the decrease in the engine rotational speed is apparently about the actuator with a small required flow rate.
- the supply flow rate that has been maintained so as to satisfy the required flow rate even when the engine is running at a low speed is reduced, so the effect is significant.
- the engine speed decreases.
- the accompanying reduction in the supply flow rate is similar to that caused by the decrease in the maximum discharge flow rate Q PMAX , so the effect is not clearly shown, but it can be seen in FIGS. 5 (a) to 5 (c).
- the control output value C is, the control pressure P C, and the target differential pressure [Delta] P, the effect of control in response to changes in engine speed, a large hydraulic actuator of the required flow rate as the boom cylinder 20
- all the actuators can obtain the effect of reducing the driving speed by reducing the target required flow rate ratio Rq corresponding to the engine speed when driving each actuator. It is.
- the drive speed decreases in a uniform manner (for example, the engine speed decreases) as the engine speed decreases, resulting in low engine speed. This avoids a situation in which driving of one of the actuators is felt faster relative to the other actuators when the engine is driven by a number.
- the standard map M ⁇ b> 1 or the low speed traveling map M ⁇ b> 2 shown in FIG. 8A is selected as described above.
- the controller 50 determines that the movable swash plates 23a and 24a of the travel motors 23 and 24 are at a small tilt angle (small capacity) position based on signals from the shift switch 26 and the travel detection means 53.
- the excavation turning work machine 10 is set to the normal mode regardless of whether or not the traveling motors 23 and 24 are actually in the driving state (traveling state)
- the standard map M1 is selected from the map group stored in the storage unit 51.
- the controller 50 determines that the travel motors 23 and 24 are in the drive state (travel state). If not, the standard map M1 is selected to set the excavation turning work machine 10 to the normal mode. When it is determined that the traveling motors 23 and 24 are actually in the driving state (traveling state), the excavation turning work machine 10 is set to the low speed traveling mode, and the map group stored in the storage unit 51 is selected. The low speed travel map M2 is selected. That is, the low speed travel map M2 is selected only when the travel motors 23 and 24 in a state where the movable swash plates 23a and 24a are in the low speed position are actually driven.
- Standard map M1 and a control output value C at high idle speed and the minimum value C 0 (control output value and the control pressure P C 0), increases the control value C as the reduce the engine speed N
- the control output value C during low idle rotation is the maximum value C MAX .
- the low-speed running map M2 has a control output value C at high idle speed a large value C W than the minimum value C 0, increases the control value C as the reduce the engine speed N, the low idle rotation
- the control output value C at the same time is the same maximum value C MAX as in the normal mode setting.
- the standard map M1 along with a high idle rotational speed N H of the engine speed N to drop to low idle rotational speed N L, to increase the control output value from C, the minimum value C 0 to a maximum value C MAX
- the low-speed travel map M2 indicates that the control output value C is reduced to the minimum value C 0 as the engine speed N decreases from the high idle speed NH to the low idle speed NL . It is set to increase from a larger value CW to a maximum value CMAX at a smaller increase rate than the control output value C of the standard map M1.
- the normal mode is set by the control output value C is the minimum value C 0, the control pressure P C is zero. Therefore, the target differential pressure ⁇ P becomes the maximum target differential pressure ⁇ P 0 .
- low-speed traveling mode is set, controlled by a large value C W than the minimum value C 0 of the output value C, 0 control pressure P C of greater value P CW than occurs To do.
- the target differential pressure [Delta] P becomes smaller ⁇ PW than the maximum target differential pressure [Delta] P 0.
- the mode switching in a time low idle rotation between the two modes the control pressure P C is changed, the target differential pressure ⁇ P is changed, so that the target subjected main flow ratio Rq is changed.
- FIG. 9 is a diagram illustrating an effect that appears in the supply flow rate Q to the traveling motors 23 and 24 by switching the mode between the normal mode and the low-speed traveling mode with respect to the driving of the traveling motors 23 and 24.
- the operation amount of the travel operation levers 33a and 34a is maximized (the spool stroke S of the direction control valves 33 and 34 is the maximum value S MAX ).
- a low speed mode based on the low-speed traveling map M2, the control output value C as C W, applying a control pressure P CW to load sensing valve 7, the target differential pressure ⁇ P, the control pressure defining difference low [Delta] P W becomes than pressure [Delta] P 0 in the absence of P C, the value of the target subjected main flow ratio Rq, and smaller than the value 1 in the normal mode Rqw H ( ⁇ 1), the target Kyoyo
- the low-speed traveling map M2 determines a control output value C (C 0 ⁇ C ⁇ C MAX ) corresponding to an arbitrary engine speed N M between the high idle speed N H and the low idle speed N L. has become one of the target subjected main flow ratio Rq obtained by the control pressure P C is generated by the control output value C is in the normal mode, the target engine speed (optional engine speed at that time N M ) is a value Rqw ( ⁇ N M / N H ) that is further reduced from the value N M / N H obtained in accordance with N M ).
- the switching from the standard map M1 to the low speed travel map M2 originally corresponds to an arbitrary engine speed N as an effect appearing on the supply flow rate characteristics of the hydraulic actuator (particularly, the travel motors 23 and 24).
- a value obtained by correcting the target required flow rate ratio Rq, which is 1, using the standard map M1 (that is, subjected to deceleration control) is further corrected using the low-speed traveling map M2 (deceleration control is performed). Means.
- the target required flow rate ratio Rq 1 when the standard map M1 is used. As a result, it seems that “deceleration control” is performed for the first time by using the low speed traveling map M2.
- the target required flow rate ratio Rq becomes a common value (N L / N H ).
- the standard map M1 is switched to the low speed travel map M2, further deceleration control is performed. It will not be done.
- the deceleration control (correction of the required flow rate ratio for the traveling motors 23 and 24) accompanying the mode switching to the low-speed traveling mode is performed by the traveling motor 23 with the operation amount of the traveling operation levers 33a and 34a and the same engine speed.
- the effect is that the speed ratio (or the speed difference between the two travel speeds) of the travel speed when the 24 movable swash plates 23a, 24a are set to the normal speed position to the travel speed when the same is set to the low speed position is increased. Further, the increase in the speed ratio becomes remarkable in a region where the engine speed is high, and becomes maximum at a high idle speed.
- the movable swash plate is set in the normal mode in the engine high rotation speed region near the high idle rotation speed NH.
- the drive speed of the drive sprocket 11b can be increased (increase the travel speed) by the amount of increase in the engine speed in this region.
- the low speed travel mode the low speed position of the travel motors 23 and 24 is achieved.
- deceleration control that is, the target required flow rate ratio Rq is further reduced than in the normal mode setting.
- the traveling motors 23 and 24 In order to increase the difference between the traveling speed when the movable swash plates 23a and 24a of the traveling motors 23 and 24 are set to the normal speed position and the traveling speed when the movable swash plates 23a and 24a are set to the low speed position, they are used as the traveling motors 23 and 24.
- the movable swash plate of the hydraulic motor is designed according to a certain standard, If you want to change the angle difference, you need to change the settings, which is expensive. In this respect, since the deceleration control only needs to change the map relating to the control output value C using the existing pump control proportional valve 8, there is no increase in cost.
- the deceleration control is for changing the tilt angle of the movable swash plate 1a of the hydraulic pump 1 by adding a control pressure P C to the load sensing valve 7 to increase side, as described above, for all the actuators, The effect of reducing the required flow rate ratio is brought about.
- the traveling motors 23 and 24 are not in a driving state based on the traveling detection signal from the traveling detection means 53 described above. If it is determined, the excavation turning work machine 10 is set to the normal mode, so that the other hydraulic actuators are driven while the excavation turning work machine 10 stops traveling, that is, the boom cylinder 20, the arm cylinder 21, Regarding the driving of the bucket cylinder 22 and the like, the supply flow rate is controlled by the control of the control output value C based on the standard map M1 corresponding to the engine speed.
- the flow rate supplied to the traveling motors 23 and 24 is low.
- the control is performed by the travel map M2, and other actuators are all in accordance with the standard map M1 unless the travel motors 23 and 24 are driven and the other actuators are driven during the low speed travel. It is controlled by the supply flow rate and operates at the operation speed assumed in the normal mode.
- the lever operation amount of the travel motors 23 and 24 at the time of high idle rotation (operation amount of the travel operation levers 33a and 34a), that is, the characteristics of the required flow rate Qt R and the supply flow rate Q of the spool stroke S of the directional control valve 33, 34.
- the required flow rate Qt R increases as the spool stroke S increases, and reaches the maximum value Q RMAX at the maximum stroke S MAX .
- the excavation turning work machine 10 is a hydraulic machine including a plurality of hydraulic actuators driven by oil discharged from the variable displacement hydraulic pump 1 driven by the engine E, pump control system 5 of the control device, at the time of driving the respective hydraulic actuators, to control the flow rate of the oil discharged from the hydraulic pump 1 so as to satisfy the required flow rate Q R of the hydraulic actuator, and the change in the engine speed N in response, it is configured to correct the target value Rq ratio (Q / Q R) of the supply flow rate Q with respect to the required flow rate Q R of the hydraulic actuators.
- the plurality of hydraulic actuators include traveling motors 23 and 24 which are hydraulic motors for traveling the excavation and turning work machine 10 and whose capacity can be switched to at least two different capacities.
- the plurality of hydraulic actuators through the meter-aperture directional control valve provided in each separate, which discharge oil from the hydraulic pump 1 is supplied, the required flow rate Q R of each actuator, each directional control It is defined by the opening of the meter-in throttle of the valve.
- Load sensing pump control system 5 load sensing
- a common target value is set for all the actuators, and the flow rate of the discharge oil of the hydraulic pump is controlled so that the target value of the differential pressure ⁇ P is achieved for all the hydraulic actuators.
- the target value Rq of the ratio (Q / Q R ) By correcting the target value of the differential pressure ⁇ P, the target value Rq of the ratio (Q / Q R ) according to the change in the engine speed N and the capacity of the travel motors 23 and 24 can be switched. The target value Rq of the ratio (Q / Q R ) is corrected accordingly.
- the control pressure P C for changing the target value of the differential pressure [Delta] P which is assumed to generate at the secondary pressure of the pump control proportional valve 8 is an electromagnetic proportional valve
- a plurality of maps are stored as a correlation map of the control output value C as a current value applied to the pump control proportional valve 8 with respect to the engine speed N.
- the plurality of maps include two or more maps M1 and M2 corresponding to the at least two stages of capacity settings of the travel motors 23 and 24, respectively.
- the two or more maps M1 and M2 include a standard map M1 corresponding to the small capacity setting of the traveling motors 23 and 24 and a low speed traveling map M2 corresponding to the large capacity setting of the traveling motors 23 and 24. Only when it is confirmed that the traveling motors 23 and 24 are actually driven when the large capacity of the traveling motors 23 and 24 is set, the discharge oil of the hydraulic pump 1 using the low-speed traveling map M2 is determined. The flow rate control is performed, and other than that, the flow rate control of the discharge oil of the hydraulic pump 1 using the standard map M1 is performed.
- the ratio (speed ratio) between the output speed when the large capacity is set and the output speed when the small capacity is set of the traveling motors 23 and 24 can be changed. That is, assuming that the operation amount (spool stroke S) of the directional control valves 33 and 34 for the traveling motors 23 and 24 is constant at a constant engine speed, the output speed difference accompanying the switching of the capacity is The value may be different from the value defined by the standard of the hydraulic motor as the traveling motors 23 and 24.
- the traveling motor 23 is increased by increasing the high idle rotational speed (maximum engine rotation speed).
- the road speed can be increased by high-speed engine rotation.
- the large capacity is set, the operation is not affected by the increase in the high idle speed due to the high engine speed.
- the output speed of the hydraulic motor can be kept low so that the conventional traveling speed is easy to be reduced.
- the speed ratio can be changed by changing the set positions of the movable swash plates 23a and 24a of the travel motors 23 and 24. In this case, however, a complicated mechanism for positioning the movable swash plates 23a and 24a is used. It may be necessary to change the design, leading to high costs.
- the pump control system 5 according to the present application that corrects the target value of the differential pressure ⁇ P between the discharge pressure P P and the maximum load pressure P L, which is employed in the existing load sensing pump control system structure Need only be used when switching the capacity of the travel motors 23 and 24. For example, a structure in which two or more maps corresponding to each capacity setting of the travel motors 23 and 24 are stored. Accordingly, it is possible to provide the pump control system 5 that exhibits the above-described effects at low cost.
- correction of the target value of the differential pressure ⁇ P is, so controls the flow rate of the oil discharged from the hydraulic pump 1, not only the travel motors 23, 24, for all the actuators, the supply flow rate Q with respect to the required flow rate Q R
- Correction of the target value Rq of the ratio (Q / Q R ) is applied.
- the output speed of the traveling motors 23 and 24 at the time of setting the large capacity is kept low as described above, not only the traveling speed can be kept low but also the driving speeds of other actuators can be reduced. Along with switching to the large capacity setting, the driving speed is lowered, and the working efficiency is lowered.
- the low speed travel map M2 for setting the large capacity is used only when it is confirmed that the travel motors 23 and 24 are actually driven when the large capacity of the travel motors 23 and 24 is set.
- other actuators can be driven at a driving speed corresponding to the setting of the small capacity of the traveling motors 23 and 24, regardless of the capacity switching of the traveling motors 23 and 24, and only the traveling speed can be achieved. While keeping it low, it is possible to perform an efficient work that is not different from the small capacity setting.
- the present invention can be applied not only to the excavating and turning work machine described above, but also to any hydraulic machine control device that employs a load sensing type hydraulic pump control system.
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Abstract
Description
Claims (4)
- エンジンにて駆動される可変容量型油圧ポンプからの吐出油にて駆動される複数の油圧アクチュエータを備えた油圧機械の制御装置であって、
該制御装置は、各油圧アクチュエータの駆動時に、その油圧アクチュエータの要求流量を満たすように該油圧ポンプの吐出油の流量を制御し、かつ、エンジン回転数の変化に応じて、各油圧アクチュエータの要求流量に対する供給流量の比率の目標値を補正するよう構成されており、
該複数の油圧アクチュエータには、該油圧機械の走行用の油圧モータであって、その容量を、少なくとも二段階の異なる容量に切換設定可能であるものを含んでおり、
該制御装置は、エンジン回転数の変化に加え、該油圧モータの容量の切換に応じて、各油圧アクチュエータの要求流量に対する供給流量の比率の目標値を補正するよう構成されていることを特徴とする、油圧機械の制御装置。 - 前記複数の油圧アクチュエータには、各別に設けられる方向制御弁のメータイン絞りを介して、前記油圧ポンプからの吐出油が供給されるものであり、
前記各アクチュエータの要求流量は、各方向制御弁のメータイン絞りの開度にて画定されるものであり、
前記制御装置は、前記油圧ポンプの吐出油が有する吐出圧と各油圧アクチュエータへの供給油が有する負荷圧との間の差圧について、全アクチュエータに共通の目標値を設定しており、全油圧アクチュエータについて、該差圧の目標値を達成するように、該油圧ポンプの吐出油の流量を制御する構成であり、
該差圧の目標値を補正することにより、エンジン回転数の変化に応じての前記比率の目標値の補正、及び、前記油圧モータの容量の切換に応じての前記比率の目標値の補正を行うことを特徴とする、請求項1に記載の油圧機械の制御装置。 - 前記差圧の目標値を変化させるための制御圧を、電磁比例弁の二次圧にて生成するものとしており、
エンジン回転数に対する該電磁比例弁にかける電流値としての制御出力値の相関マップとして、複数のマップを記憶しており、
該複数のマップは、前記油圧モータの前記少なくとも二段階の容量設定ごとにそれぞれ対応した二以上のマップを含むものであることを特徴とする、請求項2に記載の油圧機械の制御装置。 - 前記二以上のマップは、前記油圧モータの小容量設定に対応する第一のマップと、該油圧モータの大容量設定に対応する第二のマップとを含み、
該油圧モータの該大容量設定時において、実際に該油圧モータが駆動される状態であることが確認されたときにのみ該第二のマップを用いての前記油圧ポンプの吐出油の流量制御が行われ、それ以外は、該第一のマップを用いての該油圧ポンプの吐出油の流量制御が行われるよう構成されていることを特徴とする、請求項3に記載の油圧機械の制御装置。
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US16/486,646 US20200056350A1 (en) | 2017-02-17 | 2018-02-06 | Control device for hydraulic machine |
KR1020187034714A KR102095146B1 (ko) | 2017-02-17 | 2018-02-16 | 유압 기계의 제어 장치 |
AU2018220395A AU2018220395A1 (en) | 2017-02-17 | 2018-02-16 | Control device for hydraulic machine |
EP18754031.5A EP3584449B1 (en) | 2017-02-17 | 2018-02-16 | Control device for hydraulic machine |
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JP (1) | JP6789843B2 (ja) |
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CN112947294A (zh) * | 2021-02-22 | 2021-06-11 | 长春汽车工业高等专科学校 | 一种基于数字孪生的汽车装配车间监控仿真系统 |
AU2020414631B2 (en) * | 2019-12-27 | 2024-01-11 | Komatsu Ltd. | Work machine control system, work machine, and work machine control method |
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JP6815268B2 (ja) * | 2017-04-19 | 2021-01-20 | ヤンマーパワーテクノロジー株式会社 | 油圧機械の制御装置 |
JP7324717B2 (ja) * | 2020-01-14 | 2023-08-10 | キャタピラー エス エー アール エル | 油圧制御システム |
US11834811B2 (en) * | 2021-10-25 | 2023-12-05 | Cnh Industrial America Llc | System and method for controlling hydraulic pump operation within a work vehicle |
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- 2018-02-16 KR KR1020187034714A patent/KR102095146B1/ko active IP Right Grant
- 2018-02-16 EP EP18754031.5A patent/EP3584449B1/en active Active
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EP3584449A4 (en) | 2020-03-04 |
EP3584449B1 (en) | 2022-10-05 |
AU2018220395A1 (en) | 2019-09-19 |
KR102095146B1 (ko) | 2020-03-30 |
EP3584449A1 (en) | 2019-12-25 |
US20200056350A1 (en) | 2020-02-20 |
KR20190003691A (ko) | 2019-01-09 |
JP6789843B2 (ja) | 2020-11-25 |
JP2018132178A (ja) | 2018-08-23 |
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