WO1992016754A1 - Circuit hydraulique dont l'exploitation est amelioree par l'intermediaire du systeme de detection de charge - Google Patents

Circuit hydraulique dont l'exploitation est amelioree par l'intermediaire du systeme de detection de charge Download PDF

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Publication number
WO1992016754A1
WO1992016754A1 PCT/JP1992/000268 JP9200268W WO9216754A1 WO 1992016754 A1 WO1992016754 A1 WO 1992016754A1 JP 9200268 W JP9200268 W JP 9200268W WO 9216754 A1 WO9216754 A1 WO 9216754A1
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WIPO (PCT)
Prior art keywords
pressure
valve
actuator
load sensing
variable displacement
Prior art date
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Ceased
Application number
PCT/JP1992/000268
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English (en)
Japanese (ja)
Inventor
Hiroshi Imai
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Komatsu Ltd
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Komatsu Ltd
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Publication of WO1992016754A1 publication Critical patent/WO1992016754A1/fr
Anticipated expiration legal-status Critical
Ceased legal-status Critical Current

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Classifications

    • 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
    • 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
    • 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
    • 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
    • F15B11/163—Servomotor systems without provision for follow-up action; Circuits therefor with two or more servomotors with sensing of servomotor demand or load for sharing the pump output equally amongst users or groups of users, e.g. using anti-saturation, pressure compensation
    • 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
    • F15B13/00—Details of servomotor systems ; Valves for servomotor systems
    • F15B13/02—Fluid distribution or supply devices characterised by their adaptation to the control of servomotors
    • F15B13/04—Fluid distribution or supply devices characterised by their adaptation to the control of servomotors for use with a single servomotor
    • F15B13/0416—Fluid distribution or supply devices characterised by their adaptation to the control of servomotors for use with a single servomotor with means or adapted for load sensing
    • F15B13/0417—Load sensing elements; Internal fluid connections therefor; Anti-saturation or pressure-compensation valves
    • 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
    • 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
    • F15B2211/25—Pressure control functions
    • F15B2211/253—Pressure margin control, e.g. pump pressure in relation to load pressure
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
    • F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
    • F15B2211/00—Circuits for servomotor systems
    • F15B2211/30—Directional control
    • F15B2211/305—Directional control characterised by the type of valves
    • F15B2211/30505—Non-return valves, i.e. check valves
    • 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
    • F15B2211/305—Directional control characterised by the type of valves
    • F15B2211/30525—Directional control valves, e.g. 4/3-directional control valve
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
    • F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
    • F15B2211/00—Circuits for servomotor systems
    • F15B2211/30—Directional control
    • F15B2211/315—Directional control characterised by the connections of the valve or valves in the circuit
    • F15B2211/31523—Directional control characterised by the connections of the valve or valves in the circuit being connected to a pressure source and an output member
    • F15B2211/31529—Directional control characterised by the connections of the valve or valves in the circuit being connected to a pressure source and an output member having a single pressure source and a single output member
    • 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
    • F15B2211/315—Directional control characterised by the connections of the valve or valves in the circuit
    • F15B2211/3157—Directional control characterised by the connections of the valve or valves in the circuit being connected to a pressure source, an output member and a return line
    • F15B2211/31576—Directional control characterised by the connections of the valve or valves in the circuit being connected to a pressure source, an output member and a return line having a single pressure source and a single output member
    • 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
    • F15B2211/32—Directional control characterised by the type of actuation
    • F15B2211/329—Directional control characterised by the type of actuation actuated by fluid pressure
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
    • F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
    • F15B2211/00—Circuits for servomotor systems
    • F15B2211/60—Circuit components or control therefor
    • F15B2211/605—Load sensing circuits
    • F15B2211/6051—Load sensing circuits having valve means between output member and the load sensing circuit
    • F15B2211/6054—Load sensing circuits having valve means between output member and the load sensing circuit using shuttle valves
    • 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
    • F15B2211/6316—Electronic controllers using input signals representing a pressure the pressure being a pilot pressure
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
    • F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
    • F15B2211/00—Circuits for servomotor systems
    • F15B2211/60—Circuit components or control therefor
    • F15B2211/635—Circuits providing pilot pressure to pilot pressure-controlled fluid circuit elements
    • F15B2211/6355—Circuits providing pilot pressure to pilot pressure-controlled fluid circuit elements having valve means
    • 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
    • F15B2211/6653—Pressure control
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
    • F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
    • F15B2211/00—Circuits for servomotor systems
    • F15B2211/70—Output members, e.g. hydraulic motors or cylinders or control therefor
    • F15B2211/71—Multiple output members, e.g. multiple hydraulic motors or cylinders
    • F15B2211/7142—Multiple output members, e.g. multiple hydraulic motors or cylinders the output members being arranged in multiple groups

Definitions

  • the present invention relates to a hydraulic circuit for improving operability of a vehicle equipped with a hydraulic drive device including a load sensing system.
  • FIG. 1 shows a schematic configuration of a hydraulic motor for traveling (hereinafter referred to as a traveling motor) and a hydraulic circuit for a boom cylinder of a hydraulic actuator for driving a working machine such as a boom, an arm, and a bucket.
  • a traveling motor a hydraulic motor for traveling
  • a boom cylinder of a hydraulic actuator for driving a working machine such as a boom, an arm, and a bucket.
  • a pump 1 driven by a power source such as an engine, and a traveling motor 2 for the left drive wheel driven by pressure oil discharged from the pump 1, and a right side Drive wheel travel motor 2R, boom cylinder 2B, and closed center directional control valve 3 that switches the direction of pressure oil sent from pump 1 to left and right travel motors 2L, 2R and boom cylinder 2B.
  • L, 3.3 B and regulator 4 for controlling the flow rate of pressure oil discharged from pump 1 It has a sensing valve (referred to as a lower LS valve) 5.
  • the discharge pressure PP of the pump 1 is led by a pilot surface 16 branched from the pump discharge circuit 6, and at the other end, the traveling motors 2L and 2R are connected.
  • load pressure P LS caries Chi highest pressure in each Akuchiyue Ichita to the, shuttle valve 1 0, 1 1 and pi Lock preparative circuit 1 2 e also is led via a direction switching valve 3
  • the pressure relief valve 8 L. 8 R 8 B provided at the outlet port of L> 3 R and 3 B respectively has the above-mentioned load pressure P LS or the via-lot surface 15 L, 15 R, 1 Guided through 5B ':, ...?
  • the pressure oil flow QA supplied to the tubing is determined by setting the pump discharge pressure to PP When the number is c and the opening area of the directional control valves 3L, 3R, 3 ⁇ is A.
  • Actuator load pressure is PLS, it can be expressed by the following formula.
  • the actuator flow QA is controlled according to the opening area A of the directional control valve, that is, the operating stroke of the operating lever. .
  • a hydraulic excavator sometimes drives a working machine such as a boom, an arm, and a bucket while traveling in a work site.
  • a working machine such as a boom, an arm, and a bucket
  • the speed reduction rate of traveling is large for the following reasons.
  • the load pressure PLS3 acts on each of the pressure supplement valves 8L, 8R, and 8B because the load pressure PLS3 of the bump cylinder is larger than the load pressures PLS1 and PLS2 of the traveling motor. Accordingly, the pressure augmentation valves 8L and 8R are throttled greatly when only traveling, and the flow rate supplied to the traveling motors 2L and 2R is reduced, so that the speed is reduced. At this time, the flow rate to each actuator can be expressed by the following equation.
  • the pressure compensation characteristic is reduced by reducing the spring tension of the pressure supplement valve 8 L> 8 R installed in the traveling hydraulic circuit so that the flow rate supplied to the traveling motors 2 L and 2 R does not decrease. It can also be done.
  • this measure has a problem in that when the vehicle makes a gentle turn from straight traveling, the traveling speed of the drive wheels on the outer side of the turning surface decreases, and the vehicle cannot be operated as intended by the operator. Disclosure of the invention
  • the present invention focuses on the above-mentioned conventional problems, and makes it possible to minimize the traveling speed ratio as much as possible and to operate the vehicle as the operator intends when traveling and driving of the work machine are performed simultaneously. It is intended to provide a hydraulic circuit for improving operability in a load sensing system.
  • the present invention provides a variable displacement hydraulic pump, an actuator driven by pressure oil discharged from the variable displacement hydraulic pump, and a flow of pressure oil supplied from the variable displacement hydraulic pump to the actuator. And a discharge amount control means for controlling the flow rate of the pressure oil discharged from the variable displacement hydraulic pump.
  • the discharge amount control means drives the displacement variable means of the variable displacement hydraulic pump.
  • a LS valve that controls the drive of the regulator according to the differential pressure between the discharge pressure of the variable displacement hydraulic pump and the load pressure of the actuator, and maintains the differential pressure at a set value.
  • a throttle is provided in the load sensing surface for transmitting the signal pressure to the pressure compensating valve provided between the directional switching valve and the actuator, and the throttle extends from this load sensing surface to the oil tank.
  • a circuit is provided with a throttle and a switching valve, and a means for switching the switching valve based on the operating condition of the actuator operating lever or the pressure condition generated by operating the operating lever is provided.
  • the means for switching the switching valve includes a means for detecting operation of the actuator operating lever, and a command current to the solenoid valve based on a detection signal output from the detecting means. It consists of a controller and a solenoid valve that transmits the pilot pressure to the switching valve.
  • the controller outputs a command current to the solenoid valve by operating at least one of the left and right travel levers for controlling the left and right travel motors and at least one of the work implement operation levers.
  • a throttle and a switching valve are provided in the ⁇ -sensing surface for transmitting the signal pressure to the pressure compensation valve, and at least one of the left and right traveling levers and at least one of the work implement operation levers are operated. Therefore, a means for switching the switching valve is provided, so that when the work machine is operated during traveling, the switching valve is switched, and oil flows to the load sensing circuit.
  • the throttle provided in this circuit causes a signal pressure lower than the maximum pressure of the load to act on the pressure supplement valve of the directional control valve that controls the traveling motor.
  • FIG. 1 is a partial hydraulic circuit diagram showing the basic configuration of the present invention
  • Fig. 2 is an enlarged cross-sectional view of the pressure augmentation valve
  • Fig. 3 is the hydraulic oil flow supplied to the traveling motor when the work implement lever is operated during traveling.
  • FIG. 4 is a partial hydraulic circuit diagram showing a basic configuration of a hydraulic drive device provided with a conventional load sensing system. BEST MODE FOR CARRYING OUT THE INVENTION
  • FIG. 1 shows the schematic configuration of the hydraulic surface for the travel motor and the boom cylinder of the work equipment actuator in the code sensing system used for the hydraulic excavator.
  • the load sensing system has one pump 1 and pump 1
  • the traveling motor 2 for the left driving wheel driven by the pressure oil discharged the traveling motor 2 R for the right driving wheel, the bump cylinder 2 B, and the left and right traveling motors 2 L, 2 R and the boom cylinder 2 from the pump 1.
  • the directional control valves 3L, 3R, 3B are respectively connected to the surfaces 6L, 6R, 6B branched from the discharge circuit 6 of the pump 1, and the directional control valves 3L, 3R, 3B to the traveling motor 2L.
  • 2R and circuits 7L, 7R, 7B leading to the boom cylinder 2B are provided with pressure compensating valves 8L, 8R, 8B, respectively.
  • the load pressure of each of the traveling motors 2 and 2R and the like of the cylinder 2B is passed through pilot circuits 9L, 9R and 9B and shuttle valves 10 and 11 respectively.
  • the maximum value PLS is guided to one end of the LS valve 5 via the pilot circuit 12.
  • variable throttle 14a is provided in the branch surface 13 of the pilot circuit 12 and the maximum value PLS of the actuator load pressure is changed to a signal pressure PLS after passing through the variable throttle 14a.
  • 'A respectively guided to the pressure recovery valves 8L, 8R, and 8B through the pilot surface paths 15L, 15R, and 15B.
  • the other end of the LS valve 5 is connected to a pilot surface path 16 branched from the circuit 6, and receives the discharge pressure PP of the pump 1.
  • the traveling levers 17L and 17R provided near the driver's seat and the operating lever 17B for driving the boom are connected to PPC valves 18L, 18R and 18B, respectively. Pilot surfaces 19L, 19R, and 19B from valves 18L, 18R, and 18B are connected to directional valves 3L, 3R, and 3B, respectively.
  • the output wires 21 L, 21 R, 21 B of the pressure switches 20 L, 20 R, 20 B for detecting the pilot pressure are all connected to the controller 22. It is connected to the.
  • a circuit 15c leading to the oil tank 15a is provided on the extension of the pilot circuit 15L, and a variable throttle 14b and a switching valve 23 are provided in the circuit 15c. ing. Also, a solenoid valve 26 is provided on a pilot surface 25 connecting the fixed hydraulic pump 24 and a part of the switching valve 23, and a solenoid is provided on the solenoid of the solenoid valve 26. Output wiring of roller 2 2 7 Is connected.
  • At least one of the pressure switches 20 L and 20 R for detecting the pilot pressure of the PPC valves 18 L and 18 R is turned on, and the pilot switch of the PPC valve 18 B is turned on.
  • the pressure switch 20B for detecting the V-to-pressure is turned ON, the command current is output to the solenoid valve 26 via the output wiring 7.
  • the signal pressure PLS 'acting on the pressure supplementary valves 8L, 8, 8B becomes lower than the PLS by passing through the variable throttle 14a.
  • the variable throttle 14 b is provided with a pressure compensating valve when the switching valve 23 is switched and the pressure oil in the pilot circuits 15 L, 15 R, and 15 B is drained through the surface path 15 c.
  • 8L Provided to maintain the signal pressure acting on 8E, 8 ⁇ above a certain value.
  • each of the pressure supplement valves 8L, 8R, 8 ⁇ comprises a check valve 8a slidable in the valve body, a supplement screw 8c, a spring 8d, and a signal pressure PLS. 'Is guided into the spring chamber 8f from the hole 8e provided in the supplementary screw 8c.
  • the hydraulic oil that has passed through the directional control valves 3 L, 3 and 3B enters the check valve 8a from the passage 8g, and pushes the supplementary piston 8c and the spring 8d to the right in FIG. , And flow into Actuate Tappo 8h.
  • the pressure in the spring chamber 8 f also becomes PLS'. If the pressure in the inlet chamber 8 g of the check valve 8a is P1, the diameter of the check valve 8a is equal to the diameter of the piston 8c. It increases by the spring force of d. However, the spring force is weak enough against the signal pressure PLS '
  • the pressure recovery valves 8L, 8R, and 8B have a characteristic that their inlet pressures PLP2 and P3 are almost equal to the signal pressure PLS '.
  • the flow rate Q3 to the boom cylinder 2B is
  • the pressure compensation function is lost, and only the check valve 8a functions. That is, the pressure compensating valve 8B acts as a check valve, and in the boom circuit, the above equation is obtained.
  • variable throttles 14a and 14b By adjusting the variable throttles 14a and 14b, the signal pressure PLS 'of the pressure compensation valves 8L and 8R Since the size of the excavator can be changed, it is possible to supply an optimal flow rate to the traveling side according to the purpose of use of the hydraulic excavator. Further, the variable diaphragms 14a and 14b may be fixed diaphragms in some cases.
  • Fig. 3 shows the relationship between the position of the stroke of the boom operation lever and the flow rate of hydraulic oil supplied to the traveling motor.
  • the hydraulic oil flow supplied to the left and right traveling motors 2L and 2R is the left and right traveling levers 17L and 17R. Is the flow rate according to the manipulated variable, and this is 100%.
  • the boom operation lever 17B is operated to the full stroke position gF in this state, when the switching valve 23 is OFF, that is, in the case of a normal load sensing system, the boom operation lever 17B is supplied to the left and right traveling motors 2L and 2B. Pressure oil flow is reduced to about 50%.
  • the switching valve 23 is ON, the flow rate of the hydraulic oil is maintained at 70 to 80%, and the low speed shock when operating the boom operation lever is small.
  • pressure switches 20L, 20B, 20B for detecting the pilot pressures of the PPC valves 18L, 18R, 18B are provided.
  • the present invention is not limited to this, and a limit switch or a proximity switch that operates when the stroke of the actuator operation lever exceeds a certain value may be used.
  • the pressure compensation characteristics of the directional control valves 3L, 3R, 3B for controlling the actuators are made variable, so that when the directional control valve 23 is switched, the directional control valves 3L, 3R , 3 B, the pressure difference before and after becomes large, the flow distribution proportional to their opening area is temporarily broken, and more pressure oil flows to a specific actuator. Therefore, if this study is applied to the left and right traveling motors 2L and 2R of the hydraulic excavator, the traveling deceleration rate when traveling and driving of the work equipment are performed at the same time is reduced, and the hydraulic excavator is operated as the operator intends. be able to. In addition, since the speed reduction during operation of the work equipment is reduced, operator fatigue is reduced and work efficiency is improved. Industrial applicability
  • the present invention is useful as a hydraulic circuit for improving the operability of a vehicle equipped with a hydraulic drive device equipped with a load sensing system, particularly a hydraulic excavator.

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  • Engineering & Computer Science (AREA)
  • General Engineering & Computer Science (AREA)
  • Physics & Mathematics (AREA)
  • Fluid Mechanics (AREA)
  • Mechanical Engineering (AREA)
  • Mining & Mineral Resources (AREA)
  • Civil Engineering (AREA)
  • Structural Engineering (AREA)
  • Operation Control Of Excavators (AREA)
  • Fluid-Pressure Circuits (AREA)

Abstract

Selon la présente invention, un taux de réduction de vitesse de roulement peut-être réduit autant que possible et un véhicule peut être exploité comme un opérateur le désire alors que le roulement et l'entraînement d'une machine de travail se font simultanément. A cet effet, un étrangleur (14a) est prévu dans un circuit de détection de charge pour transmettre un signal de pression à des soupapes (8L, 8R, 8B) de compensation de pression, montées entre des soupapes d'inversion de direction (3L, 3R, 3B) et des actionneurs (2L, 2R, 2B), un étrangleur (14b) et une soupape d'inversion (23) sont montés dans un circuit allant de ce circuit de détection de charge à un réservoir d'huile, et un moyen assurant la commande d'inversion de la soupape d'inversion (23) sur la base de conditions d'exploitation et d'autres paramètres relatifs à un levier de commande de vérin est également prévu dans ce circuit. Lorsque la machine de travail est exploitée pendant le roulement, la soupape d'inversion (23) procède à l'inversion, un bas signal de pression agit alors sur les soupapes de compensation de pression (8L, 8R, 8B) d'un moteur de roulement, et un signal de pression correspondant à la pression maximum de la charge agit sur une soupape de détection de charge (5). Ainsi la différence de pression entre les soupapes d'inversion de direction (3L, 3R), du côté roulement, est augmentée, de sorte qu'une pression d'huile beaucoup plus grande passe du côté roulement pour ainsi diminuer le taux de réduction de la vitesse de roulement.
PCT/JP1992/000268 1991-03-15 1992-03-06 Circuit hydraulique dont l'exploitation est amelioree par l'intermediaire du systeme de detection de charge Ceased WO1992016754A1 (fr)

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JP3075708A JP3006777B2 (ja) 1991-03-15 1991-03-15 ロ−ドセンシング油圧回路
JP3/75708 1991-03-15

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Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2012094991A1 (fr) * 2011-01-11 2012-07-19 徐州徐工挖掘机械有限公司 Appareil pour améliorer les caractéristiques fonctionnelles d'excavation et les caractéristiques de travail de réalisation de pente d'une excavatrice
EP1996350B1 (fr) * 2006-03-22 2014-10-22 Avdel UK Limited Clapet d'amortisseur hydraulique amélioré

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* Cited by examiner, † Cited by third party
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CN102400966B (zh) * 2011-09-29 2014-09-17 徐州重型机械有限公司 上、下车切换装置和应用该装置的供油系统及工程机械
CN104709834B (zh) * 2013-12-11 2017-08-04 北汽福田汽车股份有限公司 回转调速控制系统和起重机
CN107458459A (zh) * 2017-07-20 2017-12-12 郭向阳 行走转向驱动装置及其控制方法
CN112833058B (zh) * 2021-01-21 2023-03-31 长沙中联重科环境产业有限公司 一种负载敏感液压系统、绿篱修剪设备

Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS57116965A (en) * 1980-11-24 1982-07-21 Linde Ag Hydraulic pressure driving system with variable discharging pump
JPS61206804A (ja) * 1985-03-08 1986-09-13 Kawasaki Heavy Ind Ltd 並列多岐油圧回路

Patent Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS57116965A (en) * 1980-11-24 1982-07-21 Linde Ag Hydraulic pressure driving system with variable discharging pump
JPS61206804A (ja) * 1985-03-08 1986-09-13 Kawasaki Heavy Ind Ltd 並列多岐油圧回路

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP1996350B1 (fr) * 2006-03-22 2014-10-22 Avdel UK Limited Clapet d'amortisseur hydraulique amélioré
WO2012094991A1 (fr) * 2011-01-11 2012-07-19 徐州徐工挖掘机械有限公司 Appareil pour améliorer les caractéristiques fonctionnelles d'excavation et les caractéristiques de travail de réalisation de pente d'une excavatrice

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JPH04285303A (ja) 1992-10-09

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