EP0439621B1 - Dispositif de circuit d'alimentation en huile sous pression pour le verin hydraulique d'un engin de chantier - Google Patents

Dispositif de circuit d'alimentation en huile sous pression pour le verin hydraulique d'un engin de chantier Download PDF

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Publication number
EP0439621B1
EP0439621B1 EP90912366A EP90912366A EP0439621B1 EP 0439621 B1 EP0439621 B1 EP 0439621B1 EP 90912366 A EP90912366 A EP 90912366A EP 90912366 A EP90912366 A EP 90912366A EP 0439621 B1 EP0439621 B1 EP 0439621B1
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EP
European Patent Office
Prior art keywords
pump
pressure
diameter piston
work implement
discharge passage
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Lifetime
Application number
EP90912366A
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German (de)
English (en)
Other versions
EP0439621A4 (en
EP0439621A1 (fr
Inventor
Kiyoshi Kawasaki Fact. of K.K.K. S. SHIRAI
Teruo Kawasaki Fact. Of K.K.K. S. Akiyama
Shigeru Kawasaki Fact.Of K.K.K. S. Shinohara
Naoki Kawasaki Fact.Of K.K.K. S. Ishizaki
Takahide Kawasaki Fact.Of K.K.K. S. Takiguchi
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Komatsu Ltd
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Komatsu Ltd
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Publication of EP0439621A4 publication Critical patent/EP0439621A4/en
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Publication of EP0439621B1 publication Critical patent/EP0439621B1/fr
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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
    • 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
    • E02F9/2221—Control of flow rate; Load sensing arrangements
    • E02F9/2232—Control of flow rate; Load sensing arrangements using one or more variable displacement pumps
    • E—FIXED CONSTRUCTIONS
    • E02—HYDRAULIC ENGINEERING; FOUNDATIONS; SOIL SHIFTING
    • E02F—DREDGING; SOIL-SHIFTING
    • E02F9/00—Component parts of dredgers or soil-shifting machines, not restricted to one of the kinds covered by groups E02F3/00 - E02F7/00
    • E02F9/20—Drives; Control devices
    • E02F9/22—Hydraulic or pneumatic drives
    • E02F9/2221—Control of flow rate; Load sensing arrangements
    • E02F9/2232—Control of flow rate; Load sensing arrangements using one or more variable displacement pumps
    • E02F9/2235—Control of flow rate; Load sensing arrangements using one or more variable displacement pumps including an electronic controller
    • E—FIXED CONSTRUCTIONS
    • E02—HYDRAULIC ENGINEERING; FOUNDATIONS; SOIL SHIFTING
    • E02F—DREDGING; SOIL-SHIFTING
    • E02F9/00—Component parts of dredgers or soil-shifting machines, not restricted to one of the kinds covered by groups E02F3/00 - E02F7/00
    • E02F9/20—Drives; Control devices
    • E02F9/22—Hydraulic or pneumatic drives
    • E02F9/2278—Hydraulic circuits
    • E02F9/2296—Systems with a variable displacement pump
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
    • F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
    • F15B11/00—Servomotor systems without provision for follow-up action; Circuits therefor
    • F15B11/16—Servomotor systems without provision for follow-up action; Circuits therefor with two or more servomotors
    • 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
    • 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
    • F15B2211/40—Flow control
    • F15B2211/405—Flow control characterised by the type of flow control means or valve
    • F15B2211/40515—Flow control characterised by the type of flow control means or valve with variable throttles or orifices
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
    • F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
    • F15B2211/00—Circuits for servomotor systems
    • F15B2211/40—Flow control
    • F15B2211/405—Flow control characterised by the type of flow control means or valve
    • F15B2211/40553—Flow control characterised by the type of flow control means or valve with pressure compensating valves
    • F15B2211/40561—Flow control characterised by the type of flow control means or valve with pressure compensating valves the pressure compensating valve arranged upstream of the flow control 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
    • F15B2211/40—Flow control
    • F15B2211/41—Flow control characterised by the positions of the valve element
    • F15B2211/413—Flow control characterised by the positions of the valve element the positions being continuously variable, e.g. as realised by proportional 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
    • F15B2211/40—Flow control
    • F15B2211/415—Flow control characterised by the connections of the flow control means in the circuit
    • F15B2211/41572—Flow control characterised by the connections of the flow control means in the circuit being connected to a pressure source and an 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
    • F15B2211/40—Flow control
    • F15B2211/455—Control of flow in the feed line, i.e. meter-in control
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
    • F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
    • F15B2211/00—Circuits for servomotor systems
    • F15B2211/50—Pressure control
    • F15B2211/505—Pressure control characterised by the type of pressure control means
    • F15B2211/50509—Pressure control characterised by the type of pressure control means the pressure control means controlling a pressure upstream of the pressure control means
    • F15B2211/50536—Pressure control characterised by the type of pressure control means the pressure control means controlling a pressure upstream of the pressure control means using unloading valves controlling the supply pressure by diverting fluid to the return line
    • 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
    • F15B2211/50—Pressure control
    • F15B2211/52—Pressure control characterised by the type of actuation
    • F15B2211/526—Pressure control characterised by the type of actuation electrically or electronically
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
    • F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
    • F15B2211/00—Circuits for servomotor systems
    • F15B2211/50—Pressure control
    • F15B2211/52—Pressure control characterised by the type of actuation
    • F15B2211/528—Pressure 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
    • F15B2211/50—Pressure control
    • F15B2211/575—Pilot 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
    • F15B2211/60—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
    • F15B2211/6346—Electronic controllers using input signals representing a state of input means, e.g. joystick position
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
    • F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
    • F15B2211/00—Circuits for servomotor systems
    • F15B2211/70—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
    • F15B2211/7052—Single-acting output members
    • 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

Definitions

  • This invention relates to a hydraulic circuit apparatus for supplying fluid under pressure discharged by a hydraulic pump into hydraulic cylinders for actuating a work implement of a construction vehicle such as a power shovel or the like.
  • a hydraulic circuit apparatus arranged so as to supply fluid under pressure discharged by a hydraulic pump into hydraulic cylinders for a work implement through operating valves is heretofore well known.
  • EP-A-0 349 092 a hydraulic drive system is disclosed which may be operated in a normal mode and in a fine operation mode.
  • the discharge rate of a hydraulic pump is controlled to hold a differential pressure between a discharged pressure of the hydraulic pump and a load pressure of an actuator at a setting value.
  • the fine operation mode the flow rate supplied to the actuator at the same stroke of a control lever as that in the ordinary work is reduced to facilitate operation of the actuator at a finely adjusted speed for permitting fine operation with ease.
  • an instruction unit is only operated when the fine operation mode should be obtained.
  • the instruction unit is connected to a controller which operates a control force supplying device so arranged to apply a control force of a plunger to one end of a control valve.
  • the control valve is a part of the load-sensing control device and further comprises a drive part on the same side as the plunger and another drive part and spring on the side opposite to the plunger.
  • the control valve is used to connect a large-diameter pressure receiving portion of a regulator with a tank, with a discharge line of the pump or to connect this portion with both the tank and the discharge line at a ratio corresponding to the position of the control valve.
  • the regulator comprises a small-diameter pressure receiving portion connected to the discharge line of the pump.
  • the regulator is used for changing a swash plate of the pump and to thereby control the discharge rate of the pump and to hold the differential pressure at a setting value.
  • the present invention has for its object to provide a hydraulic circuit apparatus for supplying fluid under pressure into hydraulic cylinders for a work implement whereby stable operation of the working implement is also ensured during inching operation whereby the number of parts of the apparatus is decreased and the costs of manufacturing the apparatus is reduced.
  • the displacement regulating member of the variable displacement member of the variable displacement pump can be actuated in such a direction as to reduce the displacement of the pump by applying pushing forces to the load sensing valve so as to push its spool in such a direction as to communicate the discharge passage of the pump with the pressure receiving chamber of the large diameter piston.
  • the flow rate of fluid discharged by the variable displacement pump can be reduced, the amount of fluid under pressure to be supplied into the hydraulic cylinders for the work implement can be controlled finely to an extremely small amount so that the inching operational characteristic can be enhanced.
  • a variable displacement pump 2 driven by an engine 1 has a discharge passage 2a connected with inlets of a plurality of operating valves 3, whose outlet sides are connected by their respective conduits 4 with hydraulic cylinders 5 of work implements, respectively.
  • Each conduit 4 is provided with a pressure compensating valve 6.
  • the load pressures P LS in the conduits 4 are compared by a shuttle valve 7, and a higher load pressure P LS detected as a result of the comparison is introduced into spring chambers of the pressure compensating valves 6 so that the valves 6 may be set at a pressure corresponding to the higher load pressure P LS .
  • the fluid under pressure discharged by one variable displacement pump 2 can be supplied to the hydraulic cylinders 5 for work implement.
  • the displacement of fluid from the variable displacement pump 2 is controlled so that the difference between the discharge pressure P 1 and the load pressure P LS is always kept constant.
  • a displacement regulating member 8 of the variable displacement pump 2 is actuated by a large piston 9 in such a direction as to reduce the displacement, and by a small piston 10 in such a direction as to increase the displacement. Further, a pressure receiving chamber 9a of the large piston 9 is controlled to be selectively connected through a load sensing valve 11 either with a fluid tank or with the discharge passage 2a, and a pressure receiving chamber 10a of the small piston 10 is connected with the discharge passage 2a.
  • the above-mentioned load sensing valve 11 has a spool arranged to be pushed by the pressure in the discharge passage 2a; that is, the discharge pressure P 1 and the thrust created by a proportional position action electromagnetic solenoid 12 in such a direction as to incresed the area of its port communicating with the pressure receiving chamber 9a of the large piston 9, and also pushed by the outlet pressure in the operating valves 3; that is, the load pressure P LS in such a direction as to reduce the area of the port thereof communicating with the pressure receiving chamber 9a.
  • This load sensing valve 11 is arranged to effect control such that where the thrust created by the proportional position action electromagnetic solenoid 12 is zero, and when the difference between the discharge pressure P 1 and the load pressure P LS (P 1 - P LS ) is increased, the pressure in the pressure receiving chamber 9a of the large piston 9 is increased so as to actuate the displacement regulating member 8 in such a direction as to reduce the displacement to thereby reduce the discharge flow rate per one revolution to reduce the discharge pressure P 1 .
  • the spool of the load sensing valve 11 is pushed in such a direction as to increase the area of the port thereof communicating with the pressure receiving chamber 9a so as to increase the pressure in the chamber 9a of the large piston 9 regardless of the pressure between the discharge pressure P 1 and the load pressure P LS to move the displacement regulating member 8 in a direction to reduce the displacement, thereby reducing the flow rate of fluid per one revolution.
  • the pressure difference between the discharge pressure P 1 and the load pressure P LS is reduced by the thrust created by the proportional position action solenoid 12 so as to reduce the discharge flow rate of fluid from the variable displacement pump 12.
  • the above-mentioned proportional position action electromagnetic solenoid 12 is supplied with electric current from a controller 13, to which a mode signal from a mode change-over switch 14 is inputted.
  • a mode signal from a mode change-over switch 14 is inputted.
  • the proportional position action electromagnetic solenoid 12 is not supplied with electric current, whilst when an inching operation mode signal is inputted by the mode change-over switch 14 to the controller 13, the electromagnetic solenoid 12 is supplied with electric current.
  • the flow rate of fluid discharged by the variable displacement pump 2 becomes less than that in the normal operation, so that the flow rate of fluid to be supplied into the hydraulic cylinders 5 for work implement changes in proportion to the stroke of the operating valves 3 as shown by a dotted line "A" in Fig. 2 and becomes less than the flow rate of fluid in the normal operation as shown by a solid line B in Fig. 2, thus rendering it possible to effect fine control of the amount of fluid supplied into the hydraulic cylinders 5 for the work implement to improve the inching operation characteristic.
  • Fig. 3 shows the second embodiment of the present invention.
  • a pilot pump 15 is driven by an engine 1, and a discharge passage 15a of the pump 15 is connected through a change-over valve 16 with a pressure receiving section 11a of a load sensing valve 11.
  • the change-over valve 16 is arranged to be kept at its shut-off position I by the resilient force of a spring mounted therein, and also kept at its communicating position II when its solenoid 16 is energized.
  • the solenoid 16 is supplied with electric current from a power supply through a mode change-over switch 14 and the controller 13.
  • a change-over valve 16 is changed over to its communicating position II so that the pilot fluid under pressure from a pilot pump 15 is supplied into a pressure receiving section 11a of a load sensing valve 11, and as a result, its spool is pushed in such a direction as to increase the area of the port thereof communicating with pressure receiving chamber 9a of a large piston 9, thereby reducing the amount of fluid discharged by a variable displacement pump 2.

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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)
  • Fluid-Pressure Circuits (AREA)
  • Control Of Positive-Displacement Pumps (AREA)
  • Operation Control Of Excavators (AREA)

Abstract

Dispositif de circuit d'alimentation en huile sous pression servant à réguler le débit de décharge d'une pompe de sorte que la différence entre la pression de décharge de la pompe et la pression de charge demeure constante pendant le fonctionnement normal de l'engin de chantier, et à réguler le débit de décharge de la pompe de manière à le réduire pendant le fonctionnement précis de l'engin de chantier. Le dispositif de circuit d'alimentation en huile sous pression comprend un piston de diamètre supérieur (9) qui actionne l'organe régulateur de capacité (8) d'une pompe à capacité variable (2) dans le sens de la réduction de la capacité de la pompe; un piston de diamètre inférieur (10) qui actionne l'organe régulateur de capacité (8) de la pompe à capacité variable (2) dans le sens de l'augmentation de la capacité de la pompe, le piston de diamètre inférieur (10) présentant une chambre (10a) recevant la pression et reliée au passage de décharge (2a) de la pompe; une soupape détectrice de charge (11) qui établit/interrompt la communication entre la chambre (9a) recevant la pression dans le piston de diamètre supérieur et le passage de décharge de la pompe; des organes (12, 13, 14) conférant à la soupape de détection de charge une force de poussée s'exerçant dans le sens d'établissement de communication entre le passage de décharge de la pompe (2a) et la chambre (9a) recevant la pression dans le piston de diamètre supérieur.

Claims (4)

  1. Dispositif de circuit hydraulique qui permet d'envoyer un fluide sous pression dans plusieurs vérins hydrauliques (5) prévus pour un outillage de travail et qui est agencé de façon à relier le passage de refoulement (2a) d'une pompe à débit variable (2) aux vérins de l'outillage de travail par l'intermédiaire de valves de manoeuvre (3), le dispositif comprenant :
    un piston (9) de grand diamètre servant à actionner l'organe de régulation de volume déplacé (8) de la pompe à débit variable (2) dans le sens permettant de réduire le volume déplacé de la pompe,
    un piston (10) de petit diamètre qui comporte une chambre de réception de pression (10a) reliée au passage de refoulement (2a) de la pompe et qui est agencé de façon à actionner l'organe de régulation de volume déplacé (8) de la pompe dans le sens permettant d'augmenter le volume déplacé de la pompe (2),
    une valve de détection de charge (11) agencée de façon à relier une la chambre de réception de pression (9a) du piston (9) de grand diamètre au passage de refoulement (2a) de la pompe (2) ou à isoler cette chambre de ce passage,
    des moyens (12, 13, 14) servant à appliquer une force de poussée à la valve de détection de charge (11) de manière à repousser son obturateur-tiroir dans le sens permettant de faire communiquer le passage de refoulement (2a) de la pompe (2) avec la chambre de réception de pression (9a) du piston (9) de grand diamètre,
    des valves de compensation de pression (6) interposées entre les vérins hydrauliques (5) de l'outillage de travail et les valves de manoeuvre (3) et
    une valve (7) à deux voies servant à comparer les pressions de charge (PLS) régnant dans les conduites de sortie (4) des valves de compensation de pression (6), en vue d'introduire la pression de charge la plus grande dans la section de réception de pression prévue sur un premier côté de la valve de détection de charge (11),
    de sorte que, pendant une manoeuvre normale de l'outillage de travail, le débit de fluide refoulé par la pompe (2) est réglé d'une manière telle que la différence entre la pression de refoulement (P1) de la pompe (2) et la pression de charge (PLS) est maintenue constante en permanence, tandis que, pendant une manoeuvre pouce par pouce de l'outillage de travail, le débit de fluide refoulé par la pompe (2) est réduit.
  2. Dispositif de circuit hydraulique selon la revendication 1, caractérisé en ce que les moyens d'application de force de poussée (12, 13, 14) comprennent :
    un électro-aimant (12) à action de position proportionnelle qui est prévu sur un premier côté de la valve de détection de charge (11),
    un commutateur de changement de mode (14) prévu pour l'électro-aimant (12) et
    un dispositif de commande (13) agencé de façon à recevoir un signal de mode de manoeuvre pouce par pouce transmis par le commutateur de changement de mode (14) et à envoyer un courant électrique à l'électro-aimant (12).
  3. Dispositif de circuit hydraulique qui permet d'envoyer un fluide sous pression dans plusieurs vérins hydrauliques (5) prévus pour un outillage de travail et qui est agencé de façon à relier le passage de refoulement (2a) d'une pompe à débit variable (2) aux vérins (5) de l'outillage de travail par l'intermédiaire de valves de manoeuvre (3), le dispositif comprenant :
    un piston (9) de grand diamètre servant à actionner l'organe de régulation de volume déplacé (8) de la pompe à débit variable (2) dans le sens permettant de réduire le volume déplacé de la pompe,
    un piston (10) de petit diamètre qui comporte une chambre de réception de pression (10a) reliée au passage de refoulement (2a) de la pompe (2) et qui est agencé de façon à actionner l'organe de régulation de volume déplacé (8) de la pompe dans le sens permettant d'augmenter le volume déplacé de la pompe,
    une valve de détection de charge (11) agencée de façon à relier une la chambre de réception de pression (9a) du piston (9) de grand diamètre au passage de refoulement (2a) de la pompe (2) ou à isoler cette chambre de ce passage et
    des moyens (13, 14, 15, 16, 16a) servant à appliquer une force de poussée à la valve de détection de charge (11) de manière à repousser son obturateur-tiroir dans le sens permettant de faire communiquer le passage de refoulement (2a) de la pompe (2) avec la chambre de réception de pression (9a) du piston (9) de grand diamètre,
    de sorte que, pendant une manoeuvre normale de l'outillage de travail, le débit de fluide refoulé par la pompe (2) est réglé d'une manière telle que la différence entre la pression de refoulement (P1) de la pompe (2) et la pression de charge (PLS) est maintenue constante en permanence, tandis que, pendant une manoeuvre pouce par pouce de l'outillage de travail, le débit de fluide refoulé par la pompe (2) est réduit et
       lesdits moyens d'application de force de poussée (13, 14, 15, 16, 16a) comprennent :
    une pompe pilote (15),
    une conduite (15a) servant à introduire un fluide pilote sous pression, refoulé par la pompe pilote (15), dans une section de réception de pression (lla) prévue sur un premier côté de la valve de détection de charge (11),
    une valve de commutation (16) prévue dans la conduite (15a),
    un électro-aimant (16a) à action de position proportionnelle qui est prévu sur un premier côté de la valve de commutation (16),
    un commutateur de changement de mode (14) prévu pour l'électro-aimant (16a) et
    un dispositif de commande (13) agencé de façon à recevoir un signal de mode de manoeuvre pouce par pouce transmis par le commutateur de changement de mode (14) et à envoyer un courant électrique à l'électro-aimant (16a).
  4. Dispositif de circuit hydraulique selon la revendication 3, caractérisé en ce que des valves de compensation de pression (6) sont interposées entre les vérins hydrauliques (5) de l'outillage de travail et les valves de manoeuvre (3) et en ce qu'une valve (7) à deux voies est prévue pour comparer les pressions de charge régnant dans les conduites de sortie (4) des valves de compensation de pression (6), en vue d'introduire la pression de charge la plus grande dans la section de réception de pression prévue sur un côté de la valve de détection de charge (11).
EP90912366A 1989-08-16 1990-08-16 Dispositif de circuit d'alimentation en huile sous pression pour le verin hydraulique d'un engin de chantier Expired - Lifetime EP0439621B1 (fr)

Applications Claiming Priority (3)

Application Number Priority Date Filing Date Title
JP210053/89 1989-08-16
JP1210053A JPH0374605A (ja) 1989-08-16 1989-08-16 作業機シリンダの圧油供給装置
PCT/JP1990/001050 WO1991002904A1 (fr) 1989-08-16 1990-08-16 Dispositif de circuit d'alimentation en huile sous pression pour le verin hydraulique d'un engin de chantier

Publications (3)

Publication Number Publication Date
EP0439621A1 EP0439621A1 (fr) 1991-08-07
EP0439621A4 EP0439621A4 (en) 1993-04-28
EP0439621B1 true EP0439621B1 (fr) 1996-10-16

Family

ID=16583031

Family Applications (1)

Application Number Title Priority Date Filing Date
EP90912366A Expired - Lifetime EP0439621B1 (fr) 1989-08-16 1990-08-16 Dispositif de circuit d'alimentation en huile sous pression pour le verin hydraulique d'un engin de chantier

Country Status (5)

Country Link
EP (1) EP0439621B1 (fr)
JP (1) JPH0374605A (fr)
KR (1) KR920701692A (fr)
DE (1) DE69028913T2 (fr)
WO (1) WO1991002904A1 (fr)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE102008054880A1 (de) 2008-12-18 2010-07-01 Deere & Company, Moline Hydrauliksystem
DE102008054876A1 (de) 2008-12-18 2010-07-01 Deere & Company, Moline Hydrauliksystem

Families Citing this family (11)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2651079B2 (ja) * 1991-07-24 1997-09-10 日立建機株式会社 油圧建設機械
JP2568507Y2 (ja) * 1991-09-27 1998-04-15 株式会社小松製作所 建設機械の微操作モード制御装置
JP3064574B2 (ja) * 1991-09-27 2000-07-12 株式会社小松製作所 油圧掘削機における作業油量切換制御装置
DE4210252C1 (fr) * 1992-03-28 1993-09-02 O & K Orenstein & Koppel Ag, 13581 Berlin, De
DE4313597B4 (de) * 1993-04-26 2005-09-15 Linde Ag Verfahren zum Betreiben einer verstellbaren hydrostatischen Pumpe und dafür ausgebildetes hydrostatisches Antriebssystem
JP3477687B2 (ja) * 1993-11-08 2003-12-10 日立建機株式会社 流量制御装置
GB2311385B (en) * 1996-03-23 2000-07-19 Trinova Ltd A fluid power control circuit
DE19930618A1 (de) * 1999-07-02 2001-01-04 Mannesmann Rexroth Ag Hydraulische Steueranordnung zur Druckmittelversorgung von vorzugsweise mehreren hydraulischen Verbrauchern
JP2012092670A (ja) * 2010-10-25 2012-05-17 Kanzaki Kokyukoki Manufacturing Co Ltd ポンプユニット
DE102013216395B4 (de) 2013-08-19 2019-01-17 Danfoss Power Solutions a.s. Steuereinrichtung für hydraulische verstellpumpen und verstellpumpe mit einer steuereinrichtung
CN112703324B (zh) 2018-09-26 2023-06-06 伊格尔工业股份有限公司 流体回路

Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4487018A (en) * 1982-03-11 1984-12-11 Caterpillar Tractor Co. Compensated fluid flow control

Family Cites Families (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS5969505A (ja) * 1982-10-14 1984-04-19 Daikin Ind Ltd キヤビテ−シヨン防止回路
DE3713824A1 (de) * 1987-04-24 1988-11-03 Rexroth Mannesmann Gmbh Ventilanordnung

Patent Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4487018A (en) * 1982-03-11 1984-12-11 Caterpillar Tractor Co. Compensated fluid flow control

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE102008054880A1 (de) 2008-12-18 2010-07-01 Deere & Company, Moline Hydrauliksystem
DE102008054876A1 (de) 2008-12-18 2010-07-01 Deere & Company, Moline Hydrauliksystem

Also Published As

Publication number Publication date
EP0439621A4 (en) 1993-04-28
KR920701692A (ko) 1992-08-12
JPH0374605A (ja) 1991-03-29
DE69028913D1 (de) 1996-11-21
DE69028913T2 (de) 1997-02-13
WO1991002904A1 (fr) 1991-03-07
EP0439621A1 (fr) 1991-08-07

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