WO2016056334A1 - 建設機械の油圧制御装置 - Google Patents
建設機械の油圧制御装置 Download PDFInfo
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- WO2016056334A1 WO2016056334A1 PCT/JP2015/075269 JP2015075269W WO2016056334A1 WO 2016056334 A1 WO2016056334 A1 WO 2016056334A1 JP 2015075269 W JP2015075269 W JP 2015075269W WO 2016056334 A1 WO2016056334 A1 WO 2016056334A1
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- meter
- arm
- hydraulic
- load
- variable
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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
- F15B11/044—Systems essentially incorporating special features for controlling the speed or actuating force of an output member for controlling the speed by means in the return line, i.e. "meter out"
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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
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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
- E02F9/2264—Arrangements or adaptations of elements for hydraulic drives
- E02F9/2267—Valves or distributors
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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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- 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
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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
- F15B11/08—Servomotor systems without provision for follow-up action; Circuits therefor with only one servomotor
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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
- F15B2211/30—Directional control
- F15B2211/35—Directional control combined with flow control
- F15B2211/353—Flow control by regulating means in return line, i.e. meter-out 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
- F15B2211/40—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
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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
- F15B2211/40—Flow control
- F15B2211/415—Flow control characterised by the connections of the flow control means in the circuit
- F15B2211/41581—Flow control characterised by the connections of the flow control means in the circuit being connected to an output member and a return line
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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
- F15B2211/40—Flow control
- F15B2211/46—Control of flow in the return line, i.e. meter-out 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
- F15B2211/63—Electronic controllers
- F15B2211/6303—Electronic controllers using input signals
- F15B2211/6306—Electronic controllers using input signals representing a pressure
- F15B2211/6313—Electronic controllers using input signals representing a pressure the pressure being a 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
- F15B2211/63—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
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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
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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
- F15B2211/7053—Double-acting 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
- F15B2211/76—Control of force or torque of the output member
- F15B2211/761—Control of a negative load, i.e. of a load generating hydraulic energy
Definitions
- the present invention relates to a hydraulic control device of a construction machine provided with a hydraulic actuator.
- a construction machine such as a hydraulic shovel includes a hydraulic pump, a hydraulic actuator driven by pressure oil discharged from the hydraulic pump, and a flow control valve controlling supply and discharge of the hydraulic oil to the hydraulic actuator.
- the hydraulic actuator includes a boom cylinder for driving a boom of a front work device, an arm cylinder for driving an arm, a bucket cylinder for driving a bucket, a swing hydraulic motor for turning a swing body, and a traveling body A traveling hydraulic motor or the like for traveling, and a flow control valve is provided for each actuator.
- Each flow control valve has a meter-in throttle and a meter-out throttle, and the meter-in throttle controls the flow rate of pressure oil supplied from the hydraulic pump to the corresponding hydraulic actuator, and the meter-out throttle discharges from the hydraulic actuator to the tank Control the flow rate of pressurized oil.
- the weight of the object to be supported by the hydraulic actuator is the operating direction of the hydraulic actuator. Act as a load in the same direction as (in the following, it may be referred to as “negative load”), and the operating speed of the hydraulic actuator increases or the flow rate of pressure oil on the meter Operation (cavitation) may occur to deteriorate operability.
- Patent Document 1 has a pilot variable opening valve interposed in a meter-out line branched from the rod side line of the hydraulic cylinder and communicated to the tank, and the wide and narrow opening of the pilot variable opening valve.
- a circuit configured to control the In this circuit, when there is a tendency for the operating speed of the arm cylinder to increase due to the weight of the arm and the bucket which is a heavy load for the arm cylinder (the self weight falling tendency), the rod side is closed by throttling the pilot variable opening valve. By preventing the drop in the holding pressure of the oil chamber, the self weight drop is suppressed.
- the weight of the support object of the hydraulic actuator of the construction machine often changes.
- the weight may change due to the replacement of the attachment (working tool) attached to the tip (tip of the arm) of the front work device of the hydraulic shovel.
- attachments that are used in hydraulic shovels, such as large buckets, crushers, and small split machines, which differ in weight, and are often heavier than standard buckets.
- another heavy attachment may be mounted by the user instead of the standard bucket.
- the pressure on the rod side of the arm cylinder (that is, the meter-out pressure loss) required to prevent the increase in the extension speed of the arm cylinder and the occurrence of the breathing phenomenon (hereinafter sometimes referred to as “breathing phenomenon etc.”)
- breathing phenomenon etc. the pressure on the rod side of the arm cylinder
- the arm cylinder is extended from a state in which the arm is held substantially horizontally in the air by the arm cylinder (the arm angle at this time is zero), and is clouded to the hydraulic shovel main body side around the pivot axis of the boom tip
- the weight of an object (mainly the arm or attachment) supported by the rod of the arm cylinder acts as a negative load on the rod to generate cylinder thrust in the rod extension direction.
- the posture or weight of the object that is, the posture of the arm, the weight of the attachment, etc.
- the magnitude of the negative load the cylinder thrust in the rod extending direction
- the pressure on the rod side required to prevent the phenomenon also changes. That is, even if the opening area of the meter-out stop of the arm cylinder is designed based on a certain posture of a certain weight of the support object, if the weight or the posture of the said support object changes, it deviates from the reference , Energy loss can not be minimized.
- This kind of problem occurs not only in the above-mentioned arm cloud operation but also in the operation of other hydraulic actuators such as a bucket cloud operation by a bucket cylinder and a turning operation by a turning hydraulic motor.
- a hydraulic control device for a construction machine includes a hydraulic actuator driven by pressure oil discharged from a hydraulic pump, and supply and discharge of pressure oil to the hydraulic actuator according to a spool position.
- a load detector for detecting the magnitude of a negative load which is a load in the same direction as the operation direction of the hydraulic actuator, and In the case of one variable stop, the aperture area of the one variable stop, and in the case of a plurality of variable stops, the total value of the opening areas of the plurality of variable stops is detected by the load detector.
- the meter-out loss can be reduced according to the change in the magnitude of the negative load that the object to be supported acts on the hydraulic actuator.
- the side view of the hydraulic shovel common to each embodiment concerning the present invention The figure which showed typically the hydraulic circuit part which concerns on control of an arm cylinder among the hydraulic control apparatuses which concern on the 1st Embodiment of this invention.
- the functional block diagram which shows the processing function which the controller 45 which concerns on the 1st Embodiment of this invention comprises.
- the relationship between the angle of the arm and the thrust of the arm cylinder when the arm is clouded from a near horizontal angle to the vertical in the air.
- the relationship figure of the arm angle and the target opening area of meter out diaphragm 23a The figure which showed typically the hydraulic circuit part which concerns on control of arm cylinder 4 among the hydraulic control apparatuses which concern on the 2nd Embodiment of this invention.
- the relationship figure of the stroke of the meter out control valve 52 which concerns on the 2nd Embodiment of this invention and the flow control valve 31, and opening area.
- the functional block diagram which shows the processing function which controller 45A in a 2nd embodiment of the present invention has.
- the relationship between the arm angle and the target opening area of the meter-out stop 52a The figure which showed typically the hydraulic circuit part which concerns on control of arm cylinder 4 among the hydraulic control apparatuses which concern on the 3rd Embodiment of this invention.
- a hydraulic control device of a construction machine for example, a hydraulic shovel
- a hydraulic actuator driven by hydraulic oil discharged from a hydraulic pump
- a control valve that controls supply and discharge according to a spool position, an operating device that controls a spool position of the control valve according to an operation amount and an operation direction, and one or more flowing pressure oil discharged from the hydraulic actuator
- the load applied to the actuator which is the load in the same direction as the operation direction of the hydraulic actuator, is detected. If the number of variable stops is one, the opening area of one variable stop is used. If the number of variable stops is more than one, the total value of the opening areas of the multiple variable stops is calculated. And a controller that reduces the amount of negative load detected by the load detector.
- the magnitude of the negative load (the load added as the driving force of the hydraulic actuator) applied to the hydraulic actuator by the external force (for example, the weight of the support target of the hydraulic actuator) is
- the opening area of the one variable aperture or the opening areas of the plurality of variable apertures is detected as the magnitude of the negative load detected by the load detector and the controller is detected by the load detector is increased.
- the aperture area of the one or more variable apertures so that the total value of the two or more of the variable apertures decreases, the total value of the aperture area of the one variable aperture or the aperture area of the plurality of variable apertures is the negative It is appropriately set to a value suitable for the size of the load.
- the total area of the opening area of one variable stop or the opening area of the plurality of variable stops is Since the value is set to a value suitable for preventing breathing or the like according to the magnitude of the negative load, the occurrence of unnecessary meter-out loss can be avoided and energy loss can be reduced.
- the hydraulic actuator includes a hydraulic cylinder, a hydraulic motor and the like, and as a typical example thereof, an arm cylinder and a bucket cylinder (both hydraulic cylinders) in a hydraulic shovel correspond.
- the arm cylinder includes an arm and an attachment (for example, a bucket) attached to the tip of the arm as the support object, and in particular, when the arm cylinder performs an extending operation (during an arm cloud) Since the above-mentioned negative load may change according to the posture of the arm concerned, and the weight of the attachment concerned, the present invention will show an effect in this case.
- a sum total for detecting the pressure value of the pressure oil in the two flow paths respectively installed in two flow paths used for supplying and discharging the pressure oil to the hydraulic actuator There are two pressure sensors (for example, pressure sensors 41 and 42 described later). The force acting on the pressure oil supply side and the pressure oil discharge side of the hydraulic actuator is calculated based on the two pressure sensors, and the magnitude of the negative load can be detected by the difference between the two forces.
- the hydraulic actuator is a hydraulic cylinder
- a first pressure sensor for detecting the pressure in the bottom hydraulic chamber of the hydraulic cylinder
- a second pressure sensor for detecting the pressure in the rod hydraulic chamber of the hydraulic cylinder
- the negative load can be calculated from the detection values of the two pressure sensors, the pressure receiving area of the piston in the bottom hydraulic chamber, and the pressure receiving of the piston in the rod hydraulic chamber. is there.
- the aperture area of the one variable aperture or the sum of the aperture areas of the plurality of variable apertures An upper limit value and a lower limit value exist for each operation amount of the operating device in a range in which the value is changed by the control device, and the upper limit value and the lower limit value correspond to an increase in the operation amount of the operating device. It shall be configured to increase.
- the total area of the opening area of the one variable diaphragm or the opening area of the plurality of variable diaphragms Since the value is adjusted to a value suitable for the operation amount, it is possible to reduce the energy loss according to the operation amount of the operating device.
- the "one meter-out flow path” is a flow path through which pressure oil discharged from the hydraulic actuator flows when the hydraulic actuator operates in the same direction as the negative load.
- a first flow path (for example, an actuator line 34 described later) passing through the control valve, and the "at least one variable throttle” is provided in the control valve in the first flow path
- the first variable throttle (for example, a meter-out throttle 23a described later), and the “control device” controls the spool position of the control valve according to the increase in the magnitude of the negative load detected by the load detector. It is preferable to reduce the opening area of the said 1st variable aperture by changing.
- a control valve is usually provided. It is easy to improve the construction machine of the invention to reach the configuration of the present invention, the number of parts to be added can be suppressed, and the hydraulic control device does not become large.
- the spool position of the control valve of a normal construction machine is an operation signal output according to the operation amount of the operating device (in the case of a hydraulic shovel, the pilot pressure reduced according to the operation lever operation amount and output to the control valve
- the operation signal is appropriately corrected according to the magnitude of the negative load.
- a proportional pressure reducing valve that reduces the pilot pressure output from the operating lever according to an increase in negative load (for example, an electromagnetic proportional pressure reducing valve (electromagnetic proportional valve 44 described later))
- the proportional pressure reducing valve may be additionally provided to reduce the opening area of the first variable throttle as the negative load increases.
- the plurality of meter-out flow paths are flow paths through which pressure oil discharged from the hydraulic actuator flows when the hydraulic actuator operates in the same direction as the negative load.
- a first flow passage (for example, an actuator line 34 described later) passing through the control valve, and pressure oil discharged from the hydraulic actuator when the hydraulic actuator operates in the same direction as the negative load
- a second flow path (for example, a meter-out branch line 51 described later) branched from the middle of the first flow path, “at least one of each of the plurality of meter-out flow paths
- the first variable throttle is provided in the control valve in the first flow passage, and the opening area is increased according to the increase of the operation amount of the operating device.
- a second variable throttling device for example, a meter-out described later, which is provided in the meter-out diaphragm 23a
- the “control device” reduces the opening area of the second variable stop in response to an increase in the magnitude of the negative load detected by the load detector.
- the total value of the aperture area of the variable stop and the second variable stop may be reduced according to the increase in the magnitude of the negative load detected by the load detector.
- control can be performed using the total value of the aperture areas of the first variable aperture and the second variable aperture, so that the aperture area is controlled with only the first variable aperture as compared with the case (3).
- the control range of the opening area can be expanded. For example, in a large construction machine in which the meter-out flow rate from the hydraulic actuator relatively increases, such a wide control range of the opening area may be a design advantage.
- the discharge pressure (primary pressure) of the pilot pump may be used as the "hydraulic source of pilot pressure for the second variable throttle device", or the discharge pressure of the pilot pump
- the controller may be used to output a pilot pressure (secondary pressure) obtained by reducing the pressure of In this case, using the former "pilot pump” can secure a wider control range than the latter case using the secondary pressure of the pilot pump.
- FIG. 1 is a side view of a hydraulic shovel 301 common to the respective embodiments described below.
- the hydraulic shovel 301 shown in this figure has a traveling body 303 including one articulated front working device A, a pair of left and right cover bands 302a and 302b, and a swivel rotatably mounted on the upper portion of the traveling body 303.
- a body 304 is provided.
- traveling hydraulic motors 318a and 318b for driving the cover bands 302a and 302b are mounted on the traveling body 303.
- a swing hydraulic motor 319 for swinging the swing body 304 is provided at the central portion of the swing body 304.
- a driver's cab 305 in which an operating lever (operating device) 6 (see FIG. 2) is stored is installed on the front left side of the revolving unit 304.
- a working device A is attached to the front center of the revolving unit 304.
- the work apparatus A has a boom 310 attached to a boom foot (not shown) provided at a front central portion of the revolving unit 304 and pivotably attached to the tip of the boom 310 in the front-rear direction.
- An arm 312 and a bucket 314 which is a work tool (attachment) attached to the tip of the arm 312 so as to be vertically pivotable are provided.
- the working device A is connected to the boom foot and the boom 310, and is connected to the boom cylinder (hydraulic cylinder) 311 for swinging the boom 310 in the vertical direction, and to the boom 310 and the arm 312, thereby swinging the arm 312 in the vertical direction.
- An arm cylinder (hydraulic cylinder) 4 to be moved, and a bucket cylinder (hydraulic cylinder) 315 connected to the arm 312 and the work tool 314 and pivoting the bucket 314 in the vertical direction are provided. That is, the working device A is driven by these hydraulic cylinders 311, 4, and 315.
- the “arm cloud” described later is an operation in which the arm 312 pivots counterclockwise in FIG. 1 about the support shaft (pivotal axis) by the boom 310 by extending the arm cylinder 4.
- the “bucket cloud” is an operation in which the bucket 314 pivots counterclockwise in FIG. 1 about the support shaft of the arm by extending the bucket cylinder 315.
- the bucket 314 can be optionally replaced with any one of a grapple, a cutter, a breaker, and other attachments in addition to the bucket shown in the drawing, according to the work content of the work machine 301.
- FIG. 2 schematically shows a hydraulic circuit portion related to control of the arm cylinder 4 in the hydraulic control device according to the first embodiment of the present invention.
- the hydraulic control device includes a prime mover (for example, an engine or an electric motor) 1, a hydraulic pump 2 driven by the prime mover 1, and a discharge line (discharge flow path) 3 of the hydraulic pump 2.
- Control valve (control valve) 31 having a flow control valve (control valve) 31 for arm 312 that is connected to and controls supply and discharge of pressure oil (flow and direction of pressure oil) to arm cylinder 4 according to the spool position;
- the control lever 6 is an operating device for the arm 312 for controlling the spool position 31 according to the amount of operation and the direction of operation.
- the hydraulic pump 2 is a variable displacement type, and has a displacement volume variable member, for example, a swash plate 2a, and the swash plate 2a is controlled by the horsepower control actuator 2b so as to reduce its capacity as the discharge pressure of the hydraulic pump 2 increases. Ru.
- the flow control valve 31 is a center bypass type which causes the pump discharge flow rate to flow to the tank via the center bypass line 32 at the neutral position A, and the center bypass portion 21 is located on the center bypass line 32.
- the center bypass line 32 is connected upstream to the discharge line 3 of the hydraulic pump 2 and connected downstream to the tank 33.
- the flow control valve 31 has a pump port 31a, a tank port 31b, and actuator ports 31c and 31d.
- the pump port 31a is connected to the center bypass line 32, and the tank port 31b is connected to the tank 33.
- the actuator port 31c , 31d are connected to the bottom side and the rod side of the arm cylinder 4 via the actuator lines 34, 35.
- the control lever 6 has a lever portion 36 and a pilot pressure generating portion 37 incorporating a pair of pressure reducing valves (not shown).
- the pilot pressure generating unit 37 is connected to pilot pressure receiving units 31 e and 31 f of the flow control valve 31 via pilot lines 38 and 39.
- command pilot pressure generating section 37 operates one of the pair of pressure reducing valves according to the operation direction, and the pilot pressure according to the operation amount of lever section 36. Is output to one of the pilot lines 38, 39.
- the flow control valve 31 has a neutral position A, a switching position B and a switching position C as the switching position of the spool.
- the flow control valve 31 is switched to the switching position B as shown in FIG. It is switched.
- the actuator line 35 becomes a flow path on the meter-in side (meter-in flow path)
- the actuator line 34 becomes a flow path on the meter-out side (meter-out flow path)
- pressure oil is supplied to the bottom side of the arm cylinder 4
- the arm cylinder 4 is extended to perform an arm cloud operation.
- the flow control valve 31 is switched to the position C on the right side in the drawing.
- the actuator line 34 is a meter-in flow path
- the actuator line 35 is a meter-out flow path. Pressure oil is supplied to the rod side of the arm cylinder 4 to contract the arm cylinder 4 to perform an arm dumping operation.
- the flow control valve 31 has meter-in throttles 22a and 22b and meter-out throttles 23a and 23b, which function as variable throttles whose opening area changes in accordance with the spool position.
- the meter-in throttle 22a controls the flow rate of pressure oil supplied to the arm cylinder 4
- the meter-out throttle 23a controls the flow rate of return oil from the arm cylinder 4.
- the meter-in throttle 22b controls the flow of pressure oil supplied to the arm cylinder 4
- the meter-out throttle 23b controls the flow of return oil from the arm cylinder 4.
- the metering characteristics of the meter out diaphragm 23a in the present embodiment are shown in FIG.
- the solid line A in FIG. 3 indicates the metering characteristics of the meter-out diaphragm 23a when the arm cloud pilot pressure is applied to the flow control valve 31 in the present embodiment.
- the broken line B indicates the metering characteristics of the meter-out diaphragm 23a when the arm cloud pilot pressure is applied to the flow control valve 31 in a comparative example (see FIG. 5) described later.
- the hydraulic control apparatus assumes that the heaviest attachment (at least the heavier than the standard bucket) is attached as the attachment attached to the tip of the arm, and the arm cloud pilot The relationship between the pressure and the opening area of the meter out diaphragm 23a is designed.
- the metering characteristics of the meter-out throttle 23a of the present embodiment that is, the relationship between the stroke of the flow control valve 31 and the opening area, increases the stroke (arm cloud pilot pressure) of the control lever 6 as shown by the solid line A. Therefore, the opening area is increased, and is set so as to be larger at the same arm cloud pilot pressure as compared with the meter-out stop 23a of the comparative example (broken line B).
- the hydraulic control device is attached to the pressure sensor 41 attached to the actuator line 35 and detecting the pressure on the bottom side of the arm cylinder 4 and the actuator line 34 as its characteristic configuration.
- the pressure sensor 42 for detecting the pressure on the rod side of the arm cylinder 4 and the arm cloud pilot pressure (that is, the operation amount of the operation lever 6 at the time of arm cloud operation) attached to the pilot line 38 and output from the operation lever 6
- Pressure sensor 43, solenoid proportional valve 44 arranged in pilot line 38 and controlling pilot pressure output to pressure receiving portion 31e of flow control valve 31 according to command current value, pressure sensor 41, pressure sensor 42 and pressure
- the detection signal of the sensor 43 is input, predetermined arithmetic processing is performed, and the solenoid proportional valve And a controller (control unit) 45 for outputting a command current to 4.
- the processing function which the controller 45 comprises in FIG. 4 is shown by a functional block diagram.
- the controller 45 has an arm cylinder thrust calculation unit 45a, a meter-out opening calculation unit 45b, and a solenoid current calculation unit 45c.
- the arm cylinder thrust computing unit 45a receives the arm cylinder bottom pressure from the pressure sensor 41 and the arm cylinder rod pressure from the pressure sensor 42, and these pressure values and the bottom pressure receiving area of the arm cylinder 4 which is a prescribed value.
- the thrust of the arm cylinder 4 is calculated based on the pressure receiving area of the rod and the rod.
- arm cylinder thrust calculation unit 45a calculates the thrust of arm cylinder 4 by subtracting the product of the pressure on the rod side of arm cylinder 4 and the pressure receiving area from the product of the pressure on the bottom side of arm cylinder 4 and the pressure receiving area. Do.
- the thrust of the arm cylinder 4 calculated by the arm cylinder thrust calculation unit 45a is output to the meter-out opening calculation unit 45b.
- the pressure sensor 41 and the pressure sensor 42 are used as a load detector for detecting the size of the load acting on the arm cylinder 4 in the arm cylinder thrust calculation unit 45 a.
- the meter-out opening calculation unit 45 b is a meter according to the thrust of the arm cylinder 4 calculated by the arm cylinder thrust calculation unit 45 a and the arm cloud pilot pressure from the pressure sensor 43 using the table shown in FIG. 4.
- the target aperture area of the out-of-diaphragm 23a is calculated.
- the solenoid current calculation unit 45c calculates a solenoid current value according to the target opening area of the meter-out diaphragm 23a calculated by the meter-out opening calculation unit 45b, and the command current having the current value is used as a control signal of the solenoid proportional valve 44 Output as
- the arm cylinder thrust calculation unit 45 a calculates a load due to an external force applied to the arm cylinder 4 at the time of extension of the arm cylinder 4 (at the time of arm cloud) as the thrust of the arm cylinder 4.
- the arm cylinder thrust calculation unit 45a is a load due to an external force applied to the arm cylinder 4 at the time of arm crowding, and when a load (positive load) in the direction opposite to the extension direction of the arm cylinder 4 acts on the arm cylinder 4, the arm cylinder Calculate the thrust of 4 as a positive value.
- a positive load at the time of the arm cloud there is, for example, a force that causes an excavating object such as the ground to act on the arm cylinder 4 via the attachment 314 and the arm 312 at the time of excavating work or the like.
- a load (negative load) in the same direction as the extension direction of the arm cylinder 4 acts on the arm cylinder 4 as a load by an external force applied to the arm cylinder 4 at the arm crowding, the thrust of the arm cylinder 4 becomes negative. Calculate as a value.
- a load weight load which causes the weight of the arm 312 and the attachment 314 which are objects to be supported by the arm cylinder 4 to act on the arm cylinder 4.
- the meter-out aperture calculator 45b first sets the target aperture area of the meter-out diaphragm 23a regardless of the magnitude of the thrust when the thrust of the arm cylinder 4 is a positive value. Hold at a fixed value set for each arm cloud pilot pressure.
- the target aperture area of the meter-out throttle 23a is monotonously decreased from a predetermined value (f1) as the magnitude of the thrust increases from zero.
- the target opening area of the meter-out stop 23a is set to a constant value set for each arm cloud pilot pressure.
- the target opening area of the meter-out throttle 23a is (1) less than f1 when the thrust of the arm cylinder 4 is a positive value, zero, and a negative value
- the upper limit value is taken when (2)
- the thrust of arm cylinder 4 is a negative value and gradually decreases with the increase of the thrust in the range from f1 to f2, (3) the thrust of arm cylinder 4
- the lower limit value is set in the range where f exceeds f2.
- the upper limit value and the lower limit value of the target opening area of the meter-out stop 23a set for each operation amount of the control lever 6 decrease the arm cloud pilot pressure It is set to decrease as you do. That is, the upper limit value and the lower limit value are set to increase according to the increase of the operation amount of the operation lever 6.
- the upper limit value and the maximum value of the lower limit value correspond to the metering characteristic shown by the solid line A in FIG. 3, and the minimum value corresponds to the metering characteristic shown by the broken line B in FIG.
- the arm cylinder thrust range in which the target opening area of the meter-out throttle 23a changes is from f1 to f2, and this is a common matter for all arm cloud pilot pressures.
- the range of arm cylinder thrust in which the target opening area of the meter-out throttle 23a changes may be changed for each arm cloud pilot pressure.
- FIG. 5 is a view showing a hydraulic circuit portion related to an arm cylinder of a hydraulic control device of a comparative example.
- the same reference numerals are used to refer to the portions common to the comparative example of FIG. 5 and the present embodiment of FIG. 2, and the description will be omitted.
- the pressure sensor 41, the pressure sensor 42, the pressure sensor 43, the solenoid proportional valve 44, and the controller 45 are compared with those of the present embodiment shown in FIG.
- the arm cloud pilot pressure and the opening area of the meter-out diaphragm 23a are not provided.
- the relationship (metering characteristics) is designed. That is, the opening area of the meter-out throttle 23a does not change according to the change of the arm cylinder thrust.
- the flow control valve 31 for the arm is switched to the position B in FIG. 5 in order to cloud the arm 312 above the ground (ie, in the air).
- the flow rate control valve 31 controls the extension speed of the arm cylinder 4 by controlling the discharge of return oil from the arm cylinder 4 by the meter out throttle 23a inside the control valve 31, and the free fall of the arm 312 To prevent the breathing phenomenon (cavitation). That is, the pressure required on the rod side of the arm cylinder 4 is increased by reducing the opening area of the meter-out throttle 23a and narrowing the flow path on the meter-out side, and the force required to resist the weight load of the arm 312 and the attachment 314 Is generated.
- the hydraulic shovel according to the present embodiment operates as follows. First, in the hydraulic shovel according to the present embodiment, as shown in FIG. 4, detection of a negative load acting on the arm cylinder 4 and calculation of the magnitude thereof are performed by the arm cylinder thrust calculation unit 45 a. Then, the control for reducing the opening area of the meter-out diaphragm 23a is performed by the meter-out opening calculator 45b and the solenoid current calculator 45c according to the calculated increase in the size of the negative load. Even if 314 is replaced with one having a different weight, it is possible to select the optimum aperture area of the meter-out throttle 23a according to the weight of the attachment 314 after the replacement. Therefore, according to the present embodiment, even if the weight of the object to be supported by the arm cylinder 4 (mainly attachment) changes, the magnitude of the negative load that the object to be supported causes the arm cylinder 4 to change. The meter out loss can be reduced accordingly.
- the cylinder thrust and the meter out throttle 23a according to the operation amount of the control lever 6.
- the structure which changes the relationship with the opening area of is adopted. (In 45b of FIG. 4, it is equivalent to change the control range of the opening area).
- the weight change of the support object of the arm cylinder 4 including the attachment 314 but also the optimum meter according to the change of the angle (arm angle) of the arm 312 as described below
- the opening area of the out diaphragm 23a can be selected.
- FIG. 1 The relationship between the angle of the arm 312 and the thrust of the arm cylinder 4 when the arm 312 is clouded from a nearly horizontal angle to a vertical angle in the air is shown in FIG.
- the angle of the arm with respect to the horizontal plane in a state in which the arm 312 is held substantially horizontally in the air by the arm cylinder 4 is zero, and the arm cylinder 4 is extended from this state and the arm 312 is rotated counterclockwise in FIG.
- the arm angle shall be increased when moving. Therefore, for example, in the case of an arm angle of 90 degrees, it indicates that the arm 312 is held vertically to the horizontal surface.
- the solid line A in FIG. 6 shows the load when the standard bucket is mounted by the thrust of the arm cylinder 4, and the broken line B shows the load when the attachment heavier than the standard bucket is mounted to the arm 312 as the thrust of the arm cylinder 4. It shows by.
- the thrust becomes a negative value due to the weight load of the arm 312 and the attachment 314, but from that state, as the arm angle increases to 90 degrees (vertical)
- the magnitude of the arm cylinder thrust decreases and changes to a positive value near the vertical.
- the arm cylinder thrust also changes when the arm angle is changed in this way, but the target opening area of the meter-out diaphragm 23a is calculated by the meter-out opening calculator 45b using the arm cylinder thrust and the table of FIG.
- the target opening area of the meter-out stop 23a can also be changed according to the arm angle.
- the relationship between the arm angle and the target opening area of the meter out diaphragm 23a in this case is shown in FIG.
- the solid line A indicates the target opening area of the meter-out aperture 23a when the standard bucket is mounted
- the broken line B indicates the target opening area of the meter-out aperture 23a when the arm 312 is attached with a heavier attachment than the standard bucket. Is shown.
- the aperture area of the meter-out diaphragm 23a can be optimally controlled even with respect to the magnitude of the negative load on the arm cylinder 4 which changes according to the arm angle. it can.
- the opening area of the meter-out stop 23a is constant even if the arm angle changes, in the present embodiment, the weight load (negative load) of the arm 312 and the attachment 314 is increased. Accordingly, since the opening area of the meter-out diaphragm 23a is reduced, the pressure loss on the meter-out can be reduced as compared with the comparative example, and the energy loss can be reduced.
- the operation amount of the operation lever 6 (the magnitude of the pilot pressure at arm cloud) Is adapted to change the relationship between the cylinder thrust and the opening area of the meter-out throttle 23a in accordance with.
- the object to be supported acts on the arm cylinder 4.
- the opening area of the meter-out diaphragm 23a is controlled to an optimal value for preventing the occurrence of the breathing phenomenon at the time of arm cloud operation, so even if the magnitude of the negative load changes.
- Meter-out loss can be reduced.
- FIG. 8 schematically shows a hydraulic circuit portion related to control of the arm cylinder 4 in the hydraulic control device according to the second embodiment of the present invention.
- the hydraulic control device shown in this figure has a meter out control valve 52, a solenoid proportional valve 53 for switching control of the spool position of the meter out control valve 52, and a controller 45A.
- the meter out control valve 52 is disposed on the meter out branch line 51.
- the meter-out branch line 51 is a flow path branched from the middle of the actuator line 34 serving as a meter-out flow path at the time of arm crowding, and is a flow path leading to the tank 33.
- a branch point on the actuator line 34 of the meter-out branch line 51 is located between the arm cylinder 4 and the flow control valve 31.
- the meter-out control valve 52 is a two-port two-position valve, and includes a meter-out throttle 52 a and a pressure receiving portion 52 b.
- the pressure receiver 52b is connected to the signal pressure line 54 branched from the pilot line 38 for outputting the arm cloud command.
- a solenoid proportional valve 53 is disposed in the signal pressure line 54. The solenoid proportional valve 53 reduces the arm cloud pilot pressure input through the pilot line 38 in accordance with the spool position determined by the command current output from the controller 45A, and controls the pilot pressure after the pressure reduction.
- the signal pressure of 52 is output to the pressure receiving unit 52b.
- the meter-out loss is reduced by controlling the opening area of only the meter-out throttle 23a in the flow control valve 31 according to the magnitude of the negative load.
- the sum of the opening area of the meter-out throttle 23a in the flow control valve 31 and the opening area of the meter-out throttle 52a in the meter-out control valve 52 is controlled according to the magnitude of the negative load.
- the main feature is to reduce the meter-out loss in this embodiment, and in the present embodiment, the two diaphragms 23a, 23a, by changing the aperture area of the meter-out diaphragm 52a according to the magnitude of the negative load. The total value of the open areas of 52a is controlled.
- the metering characteristics of the meter-out throttle 52a and the meter-out throttle 23a in the present embodiment that is, the relationship between the stroke (spool position) of the meter-out control valve 52 and the flow control valve 31 and the opening area is shown in FIG.
- the solid line A shows the metering characteristics of the meter out throttle 52a when the arm cloud pilot pressure is applied to the meter out control valve 52
- the broken line B when the arm cloud pilot pressure is applied to the flow control valve 31.
- the metering characteristic of the arm cylinder 4 at the time of the arm cloud is determined by the total value of the target opening areas of the two apertures 52a and 23a.
- the two apertures The total value of the target opening areas 52a and 23a may be set to match or approach the metering characteristic of the solid line A in FIG. 3, and in this case, the metering characteristic of the present embodiment is the first implementation. It is equivalent to the form of
- the target opening area (solid line A) of the meter-out throttle 52a is changed according to the magnitude of the negative load (the magnitude of the arm cylinder thrust) acting on the arm cylinder 4 (described later)
- the target aperture area (broken line B) of the meter-out stop 23a is set so as not to change according to the magnitude of the negative load.
- the characteristic of the aperture area of the two apertures 52a and 23a described here is only an example, and the total value of the aperture areas of the two apertures 52a and 23a is a negative load as in the first embodiment. There is no particular limitation as long as it is set to change in accordance with the size of.
- the opening area is set so that the solid line A is located below the broken line B, but the metering characteristics of the broken line B and the solid line A may be the same.
- the solid line A may be set to be positioned.
- the controller 45A receives detection signals of the pressure sensor 41, the pressure sensor 42, and the pressure sensor 43, calculates a solenoid current value by performing predetermined arithmetic processing based on the detection signals, and outputs a command current having the current value. Is output to the solenoid proportional valve 53.
- FIG. 10 is a functional block diagram showing processing functions provided by the controller 45A in the present embodiment.
- the controller 45A according to the present embodiment has a meter-out opening calculation unit 45d as a part different from the controller 45 of the first embodiment.
- the meter-out opening calculation unit 45 d calculates the target opening area of the meter-out diaphragm 52 a according to the thrust of the arm cylinder 4 and the arm cloud pilot pressure using the table shown in FIG. 10.
- the meter-out aperture calculation unit 45d first sets the target aperture area of the meter-out stop 52a regardless of the magnitude of the thrust. Is held at a constant value set for each arm cloud pilot pressure.
- the target aperture area of the meter-out throttle 52a is monotonously decreased from a predetermined value (f1) as the magnitude of the thrust increases from zero.
- the target aperture area of the meter-out stop 52a is set to zero.
- the target opening area of the meter-out throttle 52a is (1) less than f1 when the thrust of the arm cylinder 4 is a positive value, zero, and a negative value
- the upper limit value is taken when (2)
- the thrust of arm cylinder 4 is a negative value and gradually decreases with the increase of the thrust in the range from f1 to f2, (3) the thrust of arm cylinder 4 Is set to take zero (lower limit value) in the range where f exceeds f2.
- the upper limit value of the target opening area of the meter-out throttle 52a (arm cylinder thrust is negative and less than f1 is set for each operation amount of the control lever 6 (arm cloud pilot pressure) When zero and positive) are set to decrease as the arm cloud pilot pressure decreases. That is, the upper limit value is set to increase as the operation amount of the operation lever 6 increases.
- the total value of the aperture areas of the two apertures 52a and 23a is controlled to decrease according to the increase in the magnitude of the negative load as in the first embodiment (for example, at the time of arm cloud)
- the hydraulic control device of the first embodiment Will work as well.
- the opening area of the two throttles 52a, 23a is an optimal value for the size of the negative load (weight load) at that time. Therefore, the meter-out loss can be reduced according to the change in the magnitude of the negative load that the object to be supported acts on the arm cylinder 4.
- the opening area of the meter-out diaphragm 52a and the opening area of the meter-out diaphragm 23a can be controlled to a value optimum for the weight change of the support object of the arm cylinder 4, but also the arm angle It can control to the optimal value according to the change of.
- FIG. 1 The relationship between the arm angle and the thrust of the arm cylinder 4 when the arm 312 is clouded from a near horizontal angle to a vertical angle in the air is shown in FIG.
- the solid line A in the figure shows the load when the standard bucket is mounted by the thrust of the arm cylinder 4
- the broken line B shows the load when the attachment heavier than the standard bucket is mounted to the arm 312 by the thrust of the arm cylinder 4.
- the arm cylinder thrust becomes a negative value due to the weight load of the arm 312 and the attachment 314, but the arm cylinder thrust decreases as the arm angle approaches vertical, and positive near the vertical It becomes a value.
- FIG. 12 shows the relationship between the arm angle at this time and the target opening area of the meter-out stop 52a.
- the solid line A in the figure shows the target opening area of the meter-out throttle 52a when the standard bucket is mounted
- the broken line B shows the target opening area of the meter-out throttle 52a when the arm is attached with a heavier attachment than the standard bucket. ing.
- the target opening area is narrowed in a state where the arm angle is close to zero, but increases as the arm angle approaches vertical and reaches the maximum value.
- the target opening area has a minimum value (ie, zero) at an angle close to zero when the arm angle approaches zero, but increases as the angle of the arm approaches vertical. It becomes the maximum value.
- the weight load (negative load) of the arm 312 and the attachment 314 Since the sum of the aperture area of the meter-out diaphragm 52a and the aperture area of the meter-out diaphragm 23a is reduced according to the increase in size, the meter-out pressure loss is reduced and the energy loss is reduced compared to the comparative example. And since this operation
- the object to be supported acts on the arm cylinder 4
- the sum of the aperture area of the meter-out diaphragm 52a and the aperture area of the meter-out diaphragm 23a is controlled to an optimum value for preventing the occurrence of breathing during arm cloud operation.
- the meter out loss can be reduced even if the size changes.
- variable throttles 23a and 52a are installed in the two meter-out flow paths 34 and 51, respectively, and the total value of the opening areas of the two variable throttles 23a and 52a is the meter at the arm cloud Since the ring characteristic can be determined, the controllable range of the aperture area can be expanded as compared with the first embodiment in which the metering characteristic is determined only by the variable aperture 23a.
- This feature is, for example, a design advantage for a large construction machine that tends to have a large meter-out flow rate from the hydraulic actuator.
- the pilot pressure (pilot pump (pilot pump (not shown) shown in FIG. 6) is outputted from the control lever 6 as a hydraulic pressure source of pilot pressure for acting on the pressure receiving portion 52b to change the spool position of the meter out control valve 52. Since it is obtained by reducing the discharge pressure (primary pressure), it is sometimes referred to as secondary pressure), but primary pressure may be used instead of secondary pressure. That is, as the pilot pressure of the meter out control valve 52, the discharge pressure of the pilot pump may be used. An embodiment in this case will be described as a third embodiment of the present invention with reference to FIG.
- FIG. 13 is a view schematically showing a hydraulic circuit portion related to control of the arm cylinder 4 in the hydraulic control device according to the third embodiment of the present invention.
- the primary side of the solenoid proportional valve 53 in this figure is not connected to the arm cloud command side pilot line 38 as shown in FIG. Instead, the primary side of the solenoid proportional valve 53 is connected to a pilot hydraulic pressure source 55 to which the discharge pressure from a pilot pump (not shown) is input.
- the controller 45B of the present embodiment is a total value of the opening areas of the two diaphragms 52a and 23a, similarly to the controller 45A of the second embodiment. Is controlled in accordance with the magnitude of the arm cylinder thrust.
- the pilot hydraulic pressure source 55 for the primary pressure of the solenoid proportional valve 53 by using the pilot hydraulic pressure source 55 for the primary pressure of the solenoid proportional valve 53, meter-out control compared to the case of the second embodiment using the arm cloud pilot pressure for the primary pressure. Since the upper limit value of the pilot pressure of the valve 52 can be increased, the control range of the opening area of the meter-out throttle 52a can be expanded. The configuration is a great advantage especially when the arm cloud pilot pressure is low.
- the aperture area of one of the two variable apertures 23a and 52a is changed according to the magnitude of the arm cylinder thrust. If the total value of the opening area of both 23a and 52a can be controlled to decrease according to the increase of negative load, the opening area of both 23a and 52a changes according to the magnitude of the arm cylinder thrust You may
- the hydraulic control device has a configuration in which pressure oil is discharged from the arm cylinder 4 to the tank via the two meter-out flow paths 34 and 51 at the time of the arm crowding.
- there may be three or more meter-out flow paths in the arm cloud in which case at least one variable throttle is installed in each of the three or more meter-out flow paths, and the three or more meter-out flow
- the meter-out loss may be reduced by changing the total value of the opening area of at least one of the variable throttles installed in each of the paths according to the magnitude of the arm cylinder thrust.
- the present invention is applied to the valve device of the arm cylinder 4 of the hydraulic shovel to reduce the loss at the arm cloud, but at the bucket cloud extension of the bucket cylinder 315
- the present invention may be applied to the valve device of the bucket cylinder 315 because the same problem arises.
- the hydraulic circuit shown in FIG. 2 replaces the arm cylinder 4 with the bucket cylinder 315, replaces the flow control valve 31 for the arm with the flow control valve for the bucket, and operates the operating lever 6 for the arm for the bucket It should be replaced with a lever.
- valves of actuators for example, traveling hydraulic motor 318 and swing hydraulic motor 319) other than the arm cylinder 4 and bucket cylinder 315 of the hydraulic shovel
- the present invention is equally applicable to a valve device of an actuator or an actuator of a construction machine other than a hydraulic excavator (for example, a wheel loader, a crane, etc.).
- the present invention is not limited to the above-described embodiments, and includes various modifications within the scope of the present invention.
- the present invention is not limited to the one provided with all the configurations described in the above embodiment, but also includes one in which a part of the configuration is deleted.
- a part of the configuration according to an embodiment can be added to or replaced with the configuration according to another embodiment.
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Abstract
Description
Claims (5)
- 油圧ポンプから吐出される圧油により駆動される油圧アクチュエータと、
当該油圧アクチュエータに対する圧油の給排をスプール位置に応じて制御する制御弁と、
当該制御弁のスプール位置を操作量及び操作方向に応じて制御する操作装置と、
前記油圧アクチュエータから排出される圧油が流れる1つ又は複数のメータアウト流路と、
前記1つのメータアウト流路に設けられた少なくとも1つの可変絞り、又は、前記複数のメータアウト流路のそれぞれに少なくとも1つ設けられた可変絞りと、
外力により前記油圧アクチュエータに加えられる負荷であって、当該油圧アクチュエータの動作方向と同じ方向の負荷である負の負荷の大きさを検出する負荷検出器と、
前記可変絞りが1つの場合には当該1つの可変絞りの開口面積を、前記可変絞りが複数の場合には当該複数の可変絞りの開口面積の合計値を、前記負荷検出器により検出される負の負荷の大きさの増加に応じて低減する制御装置と
を備えることを特徴とする建設機械の油圧制御装置。 - 請求項1に記載の建設機械の油圧制御装置において、
前記負荷検出器により検出される負の負荷の大きさの増加に応じて前記1つの可変絞りの開口面積又は前記複数の可変絞りの開口面積の合計値が前記制御装置により変化される範囲には、前記操作装置の操作量ごとに上限値と下限値が存在し、
当該上限値と当該下限値は、前記操作装置の操作量の増加に応じて増加されることを特徴とする建設機械の油圧制御装置。 - 請求項2に記載の建設機械の油圧制御装置において、
前記1つのメータアウト流路は、前記油圧アクチュエータが前記負の負荷と同じ方向に動作するときに当該油圧アクチュエータから排出される圧油が流れる流路であって、前記制御弁内を通過する第1流路であり、
前記少なくとも1つの可変絞りは、当該第1流路における前記制御弁内に設けられた第1可変絞りであり、
前記制御装置は、前記負荷検出器により検出される負の負荷の大きさの増加に応じて前記制御弁のスプール位置を変更することで前記第1可変絞りの開口面積を低減することを特徴とする建設機械の油圧制御装置。 - 請求項2に記載の建設機械の油圧制御装置において、
前記複数のメータアウト流路は、
前記油圧アクチュエータが前記負の負荷と同じ方向に動作するときに当該油圧アクチュエータから排出される圧油が流れる流路であって、前記制御弁内を通過する第1流路と、
前記油圧アクチュエータが前記負の負荷と同じ方向に動作するときに当該油圧アクチュエータから排出される圧油が流れる流路であって、前記第1流路の途中から分岐する第2流路とであり、
前記複数のメータアウト流路のそれぞれに少なくとも1つ設けられた可変絞りは、
前記第1流路における前記制御弁内に設けられ、前記操作装置の操作量の増加に応じて開口面積が増加する第1可変絞りと、
前記第2流路に設けられ、油圧源から出力されるパイロット圧の増加に応じて開口面積が増加する第2可変絞り装置とであり、
前記制御装置は、前記負荷検出器により検出される負の負荷の大きさの増加に応じて前記第2可変絞りの開口面積を低減することで、前記第1可変絞りと前記第2可変絞りの開口面積の合計値を前記負荷検出器により検出される負の負荷の大きさの増加に応じて低減することを特徴とする建設機械の油圧制御装置。 - 請求項4に記載の建設機械の油圧制御装置において、
前記第2可変絞り装置に対するパイロット圧の前記油圧源は、パイロットポンプ、または、当該パイロットポンプからの圧油を減圧して出力する前記操作装置であることを特徴とする建設機械の油圧制御装置。
Priority Applications (4)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US15/506,863 US10400426B2 (en) | 2014-10-07 | 2015-09-04 | Hydraulic control system for construction machine |
KR1020177004055A KR101894981B1 (ko) | 2014-10-07 | 2015-09-04 | 건설 기계의 유압 제어 장치 |
CN201580043397.5A CN106574642B (zh) | 2014-10-07 | 2015-09-04 | 工程机械的液压控制装置 |
EP15848584.7A EP3205887B1 (en) | 2014-10-07 | 2015-09-04 | Construction machine with hydraulic control apparatus |
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JP6324347B2 (ja) * | 2015-06-01 | 2018-05-16 | 日立建機株式会社 | 建設機械の油圧制御装置 |
CN108138459B (zh) * | 2015-09-16 | 2021-05-11 | 住友重机械工业株式会社 | 挖土机 |
JP6707053B2 (ja) * | 2017-03-29 | 2020-06-10 | 日立建機株式会社 | 作業機械 |
CN109563696B (zh) | 2017-05-09 | 2021-05-07 | 日立建机株式会社 | 作业机械 |
JP6857152B2 (ja) * | 2018-03-29 | 2021-04-14 | 日立建機株式会社 | 作業機械の油圧回路 |
US11453995B2 (en) | 2018-04-17 | 2022-09-27 | Hitachi Construction Machinery Co., Ltd. | Work machine |
CN108730245A (zh) * | 2018-07-02 | 2018-11-02 | 尹财富 | 一种液压循环系统 |
JP7314404B2 (ja) * | 2020-03-30 | 2023-07-25 | 日立建機株式会社 | 作業機械 |
US11698086B2 (en) | 2020-12-18 | 2023-07-11 | Cnh Industrial America Llc | Systems and methods to control movement of a work vehicle attachment |
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- 2015-09-04 KR KR1020177004055A patent/KR101894981B1/ko active IP Right Grant
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JPH02142902A (ja) * | 1988-11-25 | 1990-06-01 | Hitachi Constr Mach Co Ltd | 油圧駆動装置 |
JP2004076904A (ja) * | 2002-08-21 | 2004-03-11 | Kobelco Contstruction Machinery Ltd | 建設機械の油圧シリンダ制御装置 |
JP2004225805A (ja) * | 2003-01-23 | 2004-08-12 | Kobelco Contstruction Machinery Ltd | 油圧ショベルの油圧回路 |
US20100132349A1 (en) * | 2007-06-12 | 2010-06-03 | Bert Brahmer | Hydraulic drive, in particular for machine tools, and method for controlling the hydraulic drive |
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CN106574642B (zh) | 2018-04-27 |
US10400426B2 (en) | 2019-09-03 |
JP6250515B2 (ja) | 2017-12-20 |
EP3205887A1 (en) | 2017-08-16 |
KR20170032390A (ko) | 2017-03-22 |
US20170275852A1 (en) | 2017-09-28 |
EP3205887A4 (en) | 2018-06-27 |
CN106574642A (zh) | 2017-04-19 |
EP3205887B1 (en) | 2019-08-07 |
KR101894981B1 (ko) | 2018-10-18 |
JP2016075358A (ja) | 2016-05-12 |
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