WO1995007390A1 - Dispositif de commande hydraulique pour engins de travaux publics - Google Patents

Dispositif de commande hydraulique pour engins de travaux publics Download PDF

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Publication number
WO1995007390A1
WO1995007390A1 PCT/JP1994/001497 JP9401497W WO9507390A1 WO 1995007390 A1 WO1995007390 A1 WO 1995007390A1 JP 9401497 W JP9401497 W JP 9401497W WO 9507390 A1 WO9507390 A1 WO 9507390A1
Authority
WO
WIPO (PCT)
Prior art keywords
hydraulic
control valve
directional control
valve
traveling
Prior art date
Application number
PCT/JP1994/001497
Other languages
English (en)
Japanese (ja)
Inventor
Shinichi Sato
Seiji Tamura
Fumimasa Saeki
Original Assignee
Hitachi Construction Machinery Co., Ltd.
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by Hitachi Construction Machinery Co., Ltd. filed Critical Hitachi Construction Machinery Co., Ltd.
Priority to EP94926381A priority Critical patent/EP0667421A4/fr
Publication of WO1995007390A1 publication Critical patent/WO1995007390A1/fr

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Classifications

    • 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
    • E02F9/2239—Control of flow rate; Load sensing arrangements using two or more pumps with cross-assistance
    • 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
    • E02F9/2292—Systems with two or more pumps

Definitions

  • the present invention relates to a hydraulic drive device provided in a construction machine such as a small hydraulic excavator and capable of performing a combined operation of lifting and lowering and traveling of a discharge plate.
  • FIG. 3 is a circuit diagram showing an example of this type of conventional hydraulic drive device.
  • This prior art includes three hydraulic pumps, a first hydraulic pump 1, a second hydraulic pump 2, and a third hydraulic pump 26, as main hydraulic pumps. Further, as an actuator driven by pressure oil discharged from the first hydraulic pump 1, a left traveling motor 4 for driving a left crawler belt forming a traveling body (not shown), and a front motor (not shown) And a bucket cylinder 6 for driving a bucket (not shown) that drives a boom, and a bucket cylinder 6 for driving a bucket (not shown) that is driven by hydraulic oil discharged from the second hydraulic pump 2.
  • the drive includes a right running motor 7 for driving a right crawler belt forming a running body (not shown), and an arm cylinder 8 for driving an arm forming a front not shown.
  • a lifting plate raising / lowering cylinder 9 for driving a discharging plate (not shown) and an operator seat (not shown) are arranged.
  • a left traveling direction control that controls the flow of pressure oil supplied from the first hydraulic pump 1 to the left traveling motor 4, the pump cylinder 5, and the socket cylinder 6 respectively.
  • Valve 3 4 a boom directional control valve 35 and a bucket directional control valve 36 are provided to control the flow of pressure oil supplied from the second hydraulic pump 2 to the right traveling motor 7 and the arm cylinder 8.
  • Right running direction control valve 37 to be controlled.
  • Arm direction control valve 38 is provided.
  • Pressure oil supplied from third hydraulic pump 26 to earth lift cylinder 9 and swing motor 10 A directional control valve 39 for raising and lowering the earth-discharge plate and a directional control valve 40 for turning which control the flow of water.
  • each of the left traveling direction control valve 34, the right traveling direction control valve 37, and the earthing plate lifting / lowering direction control valve 39 is switched. It is done by doing. That is, the hydraulic oil of the first hydraulic pump 1 is supplied to the left traveling motor 4 by switching the left traveling direction control valve 34, and the second hydraulic pump 2 is switched by switching the right traveling direction control valve 37.
  • the pressurized oil is supplied to the right running motor 7, and the pressure oil of the third hydraulic pump 26 is supplied to the discharge plate elevating cylinder 9 by switching the directional control valve 39 for raising and lowering the discharge plate.
  • the left crawler belt, right crawler belt, and earth removal plate that form a traveling body are driven, and a combined operation of lifting and lowering the earth removal plate and traveling can be performed.
  • FIG. 4 is a circuit diagram showing another example of the conventional hydraulic drive device.
  • a first hydraulic pump 1 and a second hydraulic pump 2 are provided as main hydraulic pumps.
  • the first hydraulic pump 1 is connected to a left traveling directional control valve 34 for controlling the driving of a left traveling motor 4, and a boom directional control for controlling the driving of a pump cylinder 5 downstream thereof.
  • a valve 35 and a bucket directional control valve 36 for controlling the driving of the bucket cylinder 6 are connected in parallel.
  • the second hydraulic pump 2 includes a directional control valve 39 for raising and lowering the blade, which controls the driving of the cylinder 9 for raising and lowering the blade.
  • a turning directional control valve 40 for controlling the driving of the engine 10 and an arm directional control valve 38 for controlling the driving of the arm cylinder 8 are connected in parallel.
  • a right traveling direction control valve 37 for controlling the drive of the right traveling motor 7 is provided downstream of 9, 40 and 38 o
  • On and off valve 13 provided on the line a hydraulic source 11 and a line 1 1a connecting the hydraulic source 11 and the drive of the on / off valve 13.
  • a throttle lib provided on this line 1 la One end is connected to a portion of a pipeline 11 a located between the restrictor lib and the drive unit of the on-off valve 13, and each directional control valve 39, 40, 38, 37, 36 , 35, and 34, the other end of which is connected to the tank.
  • the directional control valve for left traveling 34 and the right directional control valve for right driving 3 7 When the switch 9 is switched, the pressure oil of the second hydraulic pump 2 is supplied to the discharge plate lifting cylinder 9 by switching the discharge plate lifting direction control valve 3 9, and the discharge plate (not shown) moves up and down,
  • the directional control valve 39 for raising and lowering the earth discharging plate By switching the directional control valve 39 for raising and lowering the earth discharging plate, the connection of the pipeline 11 c to the tank is cut off, and accordingly the pressure is applied to the drive unit of the on-off valve 13, and this on-off valve 13 Is switched to the lower position, which is the communication position, by the force of the spring.
  • the left traveling direction control valve 34 and the right traveling direction control valve 37 are connected to the first hydraulic pump 1 in parallel, and the pressure of the first hydraulic pump 1 is reduced.
  • the oil is supplied to both the left running 4 and the right running motor 7 so that the left crawler and the right crawler, which form a running body (not shown), can be driven to run.
  • the combined operation of lifting and lowering the lifting plate and traveling can be realized only by providing two hydraulic pumps 1 and 2, and the manufacturing cost is lower than that of the conventional technique shown in FIG.
  • the manufacturing cost is lower than that of the conventional technique shown in FIG.
  • it is not necessary to consider the space required for the third hydraulic pump sufficient space for other equipment can be secured. It is suitable for mounting on a small excavator, etc., which is easily affected by restrictions, and is superior to the prior art shown in FIG. 3 described above.
  • the hydraulic oil from the first hydraulic pump 1 is supplied to the left traveling motor 4 and the hydraulic oil from the second hydraulic pump 2 is supplied to the right traveling motor 7 for traveling.
  • the directional control valve 39 for lifting and lowering the earth removal plate is switched to the lower position of FIG.
  • the hydraulic oil from the second hydraulic pump 2 is supplied to the bottom side of the cylinder and the cylinder is operated to extend the lifting plate raising / lowering cylinder 9, the lifting plate raising / lowering cylinder 9 is lighter than the right running motor 7.
  • the hydraulic oil of the second hydraulic pump 2 is no longer supplied to the right traveling motor 7, and the right traveling motor 7 and the left traveling motor 4 are connected to the hydraulic fluid of the first hydraulic pump 1 as described above. Drive state. Therefore, there is a problem that the traveling speed is sharply reduced compared to before, and the operability of the combined operation of the traveling and the dumping plate is deteriorated, and the work efficiency is significantly reduced.
  • an object of the present invention is to provide a hydraulic drive device for a construction machine that can suppress a sharp decrease in a traveling speed when performing a dumping plate operation with a lighter load than traveling while traveling. It is in.
  • the hydraulic drive device for a construction machine employs the following configuration. That is, it includes a first hydraulic pump, a second hydraulic pump, at least two traveling motors driven by hydraulic oil discharged from the first and second hydraulic pumps, and a lifting plate lifting / lowering cylinder.
  • a plurality of actuators, and at least two traveling direction control valves and a discharge plate for controlling the flow of hydraulic oil supplied from the first and second hydraulic pumps to each of the plurality of actuators.
  • a plurality of directional control valves including a directional control valve for lifting and lowering, and the directional control valve for lifting and lowering the discharge plate includes a load check valve on its feeder line, and a combination of lifting and lowering of the discharging plate and traveling.
  • An operable hydraulic drive for a construction machine wherein one of the two directional control valves for traveling and the directional control valve for lifting and lowering the earthing plate are provided for one of the first hydraulic pump and the second hydraulic pump. Is connected to the parallel In particular, a throttle valve is provided upstream of the load-tick valve on the feeder line of the directional control valve for lifting and lowering the earth-discharge plate.
  • a replenishing means capable of replenishing the pressurized oil is connected to the downstream side of the load check valve of the feeder line of the directional control valve for lifting and lowering the earthing plate.
  • the replenishing means includes a pilot pump as a hydraulic source.
  • at least a part of the plurality of directional control valves is a hydraulic bi-port operating type valve, and the hydraulic drive device is a pilot pump and the hydraulic pilot operating system.
  • a control lever means for generating a signal pressure corresponding to an operation amount based on the pilot pressure oil from the pilot pump and operating the corresponding directional control valve. Lot operation
  • a pilot system is further provided, and the pilot pump of the pilot operation system is also used as the pilot pump of the supply means.
  • the pressure oil discharged from the one hydraulic pump during the lowering operation of the earth discharging plate is divided and supplied to the one directional control valve for traveling and the directional control valve for lifting and lowering the earth discharging plate.
  • the opening of the throttle valve as described above.
  • the pressurized oil is supplied to the bottom side of the lifting plate raising / lowering cylinder, the pressure oil on the mouth side returns to the pipeline, and the lifting plate moves up and down.
  • the lowering of the earth removal plate is performed by the extension of the cylinder, pressure oil is supplied to the rod side of the earth removal plate lifting cylinder, and the pressure oil on the bottom side flows out to the return line.
  • the lifting plate is lifted by the shrinkage of the lifting plate lifting cylinder ⁇ )
  • the opening of the feeder line directional control valve for the earth removal plate is located upstream of the door check valve.
  • the pressure oil discharged from one of the hydraulic pumps is diverted and supplied to one of the directional control valve for traveling and the directional control valve for lifting and lowering of the earth discharging plate, whereby the traveling
  • the hydraulic oil of the second hydraulic pump can also be supplied to the traveling motor via the directional control valve, and it is possible to suppress a sudden decrease in the traveling speed during the combined operation of traveling and the earth moving plate operation. .
  • FIG. 1 is a diagram showing a small-sized hydraulic excavator as an example of a construction machine provided with the hydraulic drive device of the present invention.
  • FIG. 2 is a circuit diagram showing a hydraulic drive device for a construction machine according to one embodiment of the present invention.
  • Fig. 3 is a circuit diagram showing an example of a conventional hydraulic drive device for construction machinery.o
  • FIG. 4 is a circuit diagram showing another example of a conventional hydraulic drive device for a construction machine. BEST MODE FOR CARRYING OUT THE INVENTION
  • the small hydraulic shovel has a left crawler belt 20 forming a traveling body, a right crawler belt (not shown), and a driver's seat formed on the traveling body.
  • a revolving body 21 constituting a main body, a boom 22 provided rotatably at a position in front of the revolving body 21, and a boom 22 driven by a boom cylinder 5, and provided rotatably on the boom 22.
  • Arm 23 driven by an air cylinder 8, a bucket 24 mounted on the arm 23 so as to be rotatable, and a bucket 24 driven by a baggage cylinder 6, and provided rotatably on a traveling body.
  • a movable discharge plate 25 Driven by the cylinder 9 And a movable discharge plate 25.
  • the embodiment provided in such a small hydraulic shovel includes a first hydraulic pump 1 and a second hydraulic pump 2 as main hydraulic pumps.
  • the pilot pump 3 is provided as an auxiliary hydraulic pump.
  • the first hydraulic pump 1 includes a left traveling direction control valve 34 that controls the driving of a left traveling motor 4 that operates the left crawler belt, and a boom that controls the driving of a boom cylinder 5 that rotates the boom 22.
  • the directional control valve 35 for the boom and the directional control valve 36 for the boom for controlling the driving of the bucket cylinder 6 for rotating the bucket 24 are connected to the directional control valve 35 for the boom and the bucket.
  • the directional control valve 36 is connected downstream of the left traveling directional control valve 34 so that the hydraulic oil discharged from the first hydraulic pump 1 is supplied to the left traveling directional control valve 34 preferentially.
  • the left traveling direction control valve 34 is connected to a tandem, and the first hydraulic pump 1 is connected to a parallel via a parallel pipeline 15.
  • the second hydraulic pump 2 includes a directional control valve 39 for raising and lowering the earthing plate for controlling the driving of a cylinder 9 for rotating the earthing plate 25 for rotating the earthing plate 25, and a rotating body 21.
  • a turning direction control valve 40 for controlling the driving of the turning motor 10 for turning, an arm direction control valve 38 for controlling the driving of the arm cylinder 8 for rotating the arm 23, and a right side not shown.
  • the right running direction control valve 37 for controlling the drive of the right running motor 7 for operating the crawler belt is connected to the parallel via the parallel pipeline 16.
  • a communication for communicating the input port 11d of the left traveling directional control valve 34 with the input port 11e of the right traveling directional control valve 37 is provided.
  • Pipe 12, open / close valve 13 provided on this communication pipe 12, pilot pump 3 and drive section of open / close valve 13 Line 1 la that communicates with the valve, a throttle 1 1b provided on the line 1 1a, and a portion of the line 1 1a located between the throttle lib and the drive unit of the on-off valve 13.
  • the directional control valves 34 and 37 maintain the communication between the line 11c and the tank when the directional control valve is in the neutral position as shown in the figure or in the lower or upper switching position. , 40,
  • At least the directional control valves 35, 36, 38, 40 are valves of a hydraulic pilot operation type, and these directional control valves are of the hydraulic pilot type.
  • a pilot operation system including operation lever devices 60 and 61 for 40 is provided.
  • the operation lever device 60 generates signal pressures e, e '; f, f' according to the operation amount of the operation lever based on the pilot pressure oil from the pilot pump 3.
  • the directional control valves 40 and 38 are switched, and the operation lever device 61 receives the signal pressure g, '; h according to the operation amount of the operation lever based on the pilot pressure oil from the pilot pump 3. , h ', and switches the directional control valves 36, 35.
  • the directional control valve 39 A throttle valve 50 is provided upstream of the load check valve 53 of the feeder line 49.
  • the throttle valve 50 is used for the second operation when the traveling operation in which the load on the discharge plate 25 side is light load and the combined operation with the discharge plate 25, for example, in the combined operation of traveling and lowering operation of the discharge plate 25.
  • Hydraulic oil discharged from the hydraulic pump 2 is divided and supplied to the right traveling direction control valve 37 (right traveling motor 7) and the earth removal plate elevating direction control valve 39 (earth ejection plate elevating cylinder 9). The opening is set so that it can be adjusted.
  • one end is provided at the downstream side of the feed-check valve 53 of the feeder line 49 of the directional control valve 39 for lifting and lowering the discharge plate in order to replenish the insufficient oil due to the above-mentioned shunt by the throttle valve 50.
  • a check valve 51 connected to the other end of the pipe 52 and preventing the hydraulic oil discharged from the second hydraulic pump from flowing in the direction of the pilot pump 3;
  • a pipe 54 is connected at one end to the check valve 51, and the other end is connected to the above-mentioned pipe 11 a connected to the pilot pump 3.
  • Pilot pump 3, pipe 54, check valve 51, and pipe 52 described above are used as feed line 49 for directional control valve 39 for raising and lowering the discharge plate.
  • 3 is connected to the downstream side, and constitutes a catching means capable of catching pressurized oil.
  • the pilot pump 3 serves both as a hydraulic source for the pilot operation diameter including the operation lever devices 60 and 61 and a hydraulic source for the replenishing means.
  • Reference numeral 56 denotes a main relief valve that regulates the pressure of the hydraulic oil discharged from the first hydraulic pump 1
  • reference numeral 55 denotes a main relief valve that regulates the pressure of the hydraulic oil discharged from the second hydraulic pump 2.
  • Relief valve 57 is a pilot relief valve that regulates the pilot pressure discharged from pilot pump 3.
  • pressurized oil is supplied to the bottom side 9a of the lifting plate elevating cylinder 9, and the pressurized oil is returned to the mouth side 9b.
  • the cylinder 9 flows out into the pipe and the lifting plate elevating cylinder 9 extends, the lowering operation of the discharging plate 25 is performed, and pressurized oil is applied to the mouth side 9 b of the discharging plate elevating cylinder 9.
  • the pressurized oil on the bottom side 9a is supplied to the return pipe, and the discharge plate raising / lowering cylinder 9 contracts, whereby the discharge plate 25 is raised.
  • the left traveling directional control valve 34 and the right traveling directional control valve 37 are switched when the traveling alone is operated, the pressure oil of the first hydraulic pump 1 is supplied to the left traveling directional control valve.
  • the left traveling motor 4 is provided to the left traveling motor 4 via 3 4 and is driven to form a traveling body.
  • the left crawler belt 20 is operated, and the hydraulic oil of the second hydraulic pump 2 is moved in the right traveling direction.
  • the right traveling motor 7 is provided to the right traveling motor 7 via the control valve 37, and the right traveling motor 7 is driven to operate the right crawler belt (not shown) forming the traveling body, whereby the traveling alone operation is performed.
  • the directional control valve 39 When shifting from a single operation of such traveling to a combined operation of running with a light load on the earth removal plate and operation of the earth removal plate, for example, a combined operation of running and lowering of the earth removal plate, it is also necessary to raise and lower the earth removal plate.
  • the directional control valve 39 When the directional control valve 39 is switched, the communication between the pipeline 11C and the tank is cut off with the switching of the directional control valve 39 for lifting and lowering the discharge plate.
  • the on-off valve 13 is staken by the force of the spring, and is switched to the communication position, that is, the lower position in FIG. 2, and the input port 1 of the left traveling directional control valve 34 through the communication pipe 12 1 d and the input port 11 e of the right direction control valve 37 are in communication.
  • the pressure oil of the first hydraulic pump 1 is supplied to the left traveling motor 4 via the left traveling direction control valve 34, and the left traveling motor 4 is driven, and the left crawler belt 20 which forms the traveling body is driven.
  • a part of the pressure oil of the first hydraulic pump 1 is supplied to the right traveling direction control valve 37 via the communication pipe 12.
  • the pressure oil of the second hydraulic pump 2 is controlled by the throttle valve 50 in the right running direction.
  • the flow is divided and supplied to each of the valve 37 and the directional control valve 39 for raising and lowering the discharge plate.
  • the right directional control valve 37 is supplied to the right traveling directional control valve 37 through the communication pipe 12 described above.
  • a part of the pressure oil of the first hydraulic pump 1 and the divided pressure oil of the second hydraulic pump 2 are combined and supplied, and the combined flow rate is given to the right traveling motor 7 so that the right traveling
  • the motor 7 is driven to operate the right crawler belt (not shown) that forms the traveling body.
  • the remaining pressure oil shunted by the second hydraulic pump 2 is applied to the bottom side 9 a of the cylinder 9 for lifting plate lifting cylinder.
  • the operation is performed to extend the cylinder 9 for raising and lowering the earth discharging plate, and the operation of lowering the earth discharging plate 25 is performed. In this way, it is possible to prevent a sudden decrease in the flow rate supplied to the left traveling motor 4 and the right traveling motor 7 when the traveling and the exhaust plate operation are combined with a light load on the earth removal plate side. A rapid decrease in speed can be suppressed.
  • pilot pressure oil of the pilot pump 3 is connected to the pipeline 11 to the directional control valve 39 for raising and lowering the exhaust plate where the flow rate was insufficient due to the diverting flow during the combined operation of the exhaust plate and the above-mentioned operation. a, it can be collected via line 54, check valve 51, and line 52.Pressurized oil is used when the discharge plate work is a light load operation that requires a positive supply of pressurized oil. With this, it is possible to suppress a rapid decrease in the traveling speed at the time of the combined operation of the traveling and the dumping plate operation as described above, and also to suppress a decrease in the lifting speed of the dumping plate. .
  • the pressure oil of the second hydraulic pump 2 specified by the main relief valve 55 uses the throttle valve 50 to control the direction of lifting and lowering the discharge plate. Since it is supplied to the cylinder 9 for lifting and lowering the earth through the valve 39, it is possible to secure a sufficient speed of lifting and lowering the earth.
  • pilot pressure oil of the pilot pump 3 can be supplied to the directional control valve 39 for raising and lowering the discharge plate during the combined operation of the traveling plate and the discharge plate, It is also possible to suppress a decrease in the elevating speed, and if such a decrease in the elevating speed of the earth removal plate 25 is suppressed, further excellent operability of the combined traveling and earth removal plate operation is ensured. Work efficiency can be improved. Industrial applicability
  • the present invention has the above-described configuration, it is possible to suppress a sharp decrease in the traveling speed when performing the earth removal plate operation with a lighter load than the traveling while traveling, and it is possible to suppress such a decrease as compared with the related art. It is possible to improve the operability of the combined operation of running and dumping plate, and it is possible to secure excellent work efficiency.

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

Abstract

Ce dispositif de commande hydraulique pour engins de travaux publics comprend: 1) une première pompe hydraulique (1), 2) une seconde pompe hydraulique (2), 3) un ensemble d'actuateurs incluant au moins deux moteurs de déplacement (4, 7) mus par la pression d'huile débitée par les première et seconde pompes hydrauliques, 4) un vérin de relèvement de la lame du bouteur, 5) un ensemble de vannes de commande de direction incluant au moins deux vannes de commande de direction du déplacement (34, 37) agissant sur le débit de l'huile sous pression provenant des première et seconde pompes hydrauliques et destiné à l'ensemble des différents actuateurs, 6) une vanne de commande (39) du vérin de relèvement de la lame du bouteur, cette vanne de commande disposant d'une valve de contrôle (53) de la charge placée le long d'une tubulure d'alimentation (49) de ce vérin et ayant pour effet de combiner les mouvements de relevage et de poussée au niveau de la lame du bouteur (25). Le dispositif hydraulique est caractérisé par le fait que l'une (37) des deux vannes de commande de direction du déplacement (34, 37) et la vanne de relèvement (39) de la lame du bouteur sont raccordées en parallèle à l'une (2) des première et seconde pompes hydrauliques (1, 2) et qu'une vanne d'étranglement (50) est montée sur la tubulure de reflux de la valve de contrôle (53) de la charge placée le long d'une tubulure d'alimentation (49) de la vanne de relèvement (39) de la lame du bouteur. Le dispositif hydraulique est caractérisé en outre par le fait que les ouvertures de remplissage (51, 52, 54, 3) destinées à compléter la quantité d'huile sous pression se trouvent sur la tubulure d'amenée de la valve de contrôle (53) de la charge placée le long d'une tubulure d'alimentation (49) de la vanne de relèvement (39) de la lame du bouteur.
PCT/JP1994/001497 1993-09-09 1994-09-09 Dispositif de commande hydraulique pour engins de travaux publics WO1995007390A1 (fr)

Priority Applications (1)

Application Number Priority Date Filing Date Title
EP94926381A EP0667421A4 (fr) 1993-09-09 1994-09-09 Dispositif de commande hydraulique pour engins de travaux publics.

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
JP5224595A JPH0776859A (ja) 1993-09-09 1993-09-09 建設機械の油圧駆動装置
JP5/224595 1993-09-09

Publications (1)

Publication Number Publication Date
WO1995007390A1 true WO1995007390A1 (fr) 1995-03-16

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Application Number Title Priority Date Filing Date
PCT/JP1994/001497 WO1995007390A1 (fr) 1993-09-09 1994-09-09 Dispositif de commande hydraulique pour engins de travaux publics

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EP (1) EP0667421A4 (fr)
JP (1) JPH0776859A (fr)
WO (1) WO1995007390A1 (fr)

Families Citing this family (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH1037907A (ja) * 1996-07-26 1998-02-13 Komatsu Ltd 圧油供給装置
JP6575916B2 (ja) * 2016-08-17 2019-09-18 日立建機株式会社 作業車両

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JPS60144432A (ja) * 1983-12-30 1985-07-30 Handoothe- Kogyo Kk ド−ザ−付き掘削機における油圧回路
JPS6490325A (en) * 1987-09-29 1989-04-06 Hitachi Construction Machinery Oil-pressure driver
JPH01120562U (fr) * 1988-02-01 1989-08-15
JPH0455529A (ja) * 1990-06-26 1992-02-24 Hitachi Constr Mach Co Ltd 作業機械の油圧回路

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US4024710A (en) * 1976-03-25 1977-05-24 Koehring Company Load sensing hydraulic circuit having power matching means
US4112821A (en) * 1976-12-03 1978-09-12 Caterpillar Tractor Co. Fluid control system for multiple circuited work elements
DE3271311D1 (en) * 1981-03-03 1986-07-03 Hitachi Construction Machinery Hydrostatic drive system for civil engineering and construction machinery
FI823729L (fi) * 1982-11-01 1984-05-02 Valmet Oy Hydrauliksystem foer en traktor eller liknande
JPS6131535A (ja) * 1984-07-20 1986-02-14 Kayaba Ind Co Ltd 建設車両等の油圧制御回路
DE3644745A1 (de) * 1986-12-30 1988-07-14 Rexroth Mannesmann Gmbh Steueranordnung fuer mindestens zwei von mindestens einer pumpe gespeiste hydraulische verbraucher
JP2511629Y2 (ja) * 1988-05-16 1996-09-25 株式会社小松製作所 油圧回路

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS60144432A (ja) * 1983-12-30 1985-07-30 Handoothe- Kogyo Kk ド−ザ−付き掘削機における油圧回路
JPS6490325A (en) * 1987-09-29 1989-04-06 Hitachi Construction Machinery Oil-pressure driver
JPH01120562U (fr) * 1988-02-01 1989-08-15
JPH0455529A (ja) * 1990-06-26 1992-02-24 Hitachi Constr Mach Co Ltd 作業機械の油圧回路

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
See also references of EP0667421A4 *

Also Published As

Publication number Publication date
EP0667421A4 (fr) 1997-12-17
EP0667421A1 (fr) 1995-08-16
JPH0776859A (ja) 1995-03-20

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