EP0279356A1 - Système hydraulique pour un engin de terrassement - Google Patents

Système hydraulique pour un engin de terrassement Download PDF

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Publication number
EP0279356A1
EP0279356A1 EP88102009A EP88102009A EP0279356A1 EP 0279356 A1 EP0279356 A1 EP 0279356A1 EP 88102009 A EP88102009 A EP 88102009A EP 88102009 A EP88102009 A EP 88102009A EP 0279356 A1 EP0279356 A1 EP 0279356A1
Authority
EP
European Patent Office
Prior art keywords
pump
load sensing
valve
line
hydraulic
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.)
Granted
Application number
EP88102009A
Other languages
German (de)
English (en)
Other versions
EP0279356B1 (fr
Inventor
Steven Harold Johnson
Lary Lynn Williams
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Deere and Co
Original Assignee
Deere and Co
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 Deere and Co filed Critical Deere and Co
Publication of EP0279356A1 publication Critical patent/EP0279356A1/fr
Application granted granted Critical
Publication of EP0279356B1 publication Critical patent/EP0279356B1/fr
Expired 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
    • F15B11/17—Servomotor systems without provision for follow-up action; Circuits therefor with two or more servomotors using two or more 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
    • 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
    • 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
    • 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
    • F15B2211/205—Systems with pumps
    • F15B2211/20576—Systems with pumps with multiple pumps
    • 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
    • F15B2211/31—Directional control characterised by the positions of the valve element
    • F15B2211/3105—Neutral or centre positions
    • F15B2211/3111—Neutral or centre positions the pump port being closed in the centre position, e.g. so-called closed centre
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
    • F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
    • F15B2211/00—Circuits for servomotor systems
    • F15B2211/30—Directional control
    • F15B2211/35—Directional control combined with flow control
    • F15B2211/351—Flow control by regulating means in 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
    • F15B2211/30—Directional control
    • F15B2211/35—Directional control combined with flow control
    • F15B2211/353—Flow control by regulating means in return line, i.e. meter-out control
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
    • F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
    • F15B2211/00—Circuits for servomotor systems
    • F15B2211/60—Circuit components or control therefor
    • F15B2211/63—Electronic controllers
    • F15B2211/6303—Electronic controllers using input signals
    • F15B2211/6306—Electronic controllers using input signals representing a pressure
    • F15B2211/6313—Electronic controllers using input signals representing a pressure the pressure being a load pressure
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
    • F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
    • F15B2211/00—Circuits for servomotor systems
    • F15B2211/60—Circuit components or control therefor
    • F15B2211/65—Methods of control of the load sensing pressure
    • 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
    • F15B2211/6651—Control of the prime mover, e.g. control of the output torque or rotational speed
    • 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
    • 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
    • F15B2211/715—Output members, e.g. hydraulic motors or cylinders or control therefor having braking 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
    • F15B2211/70—Output members, e.g. hydraulic motors or cylinders or control therefor
    • F15B2211/78—Control of multiple output members

Definitions

  • This invention relates to an hydraulic system for a con­struction machine, e.g. an excavator, having a plurality of hydraulic motors, a variable displacement pump, an outlet line from the pump to the motors, a stroke control operatively connected to the pump, and a load sensing conduit for the motors connected to the stroke control so that when pressure in the conduit exceeds a predetermined value the stroke control increases the displacement of the pump.
  • a con­struction machine e.g. an excavator
  • Hydraulic excavators conventionally utilize hydraulic mo­tor cylinders to control the position of a main excavator boom, to control the position of an arm at the end of the boom, and to control the position of a bucket at the end of the arm.
  • an hydraulic motor is convention­ally utilized to rotate the excavator body that carries the boom on an undercarriage and it is also known to use a pair of independently controlled hydraulic motors to drive the opposite tracks of the machine's undercarriage to pro­pel and steer the machine.
  • hydraulic sys­tems have been open centre type systems.
  • the said hydraulic sys­tem (of the opening paragraph above) includes at least one further variable displacement pump and stroke control therefor and the said outlet line is common to the pumps.
  • a construction machine having such an hydraulic system is also within the concept of the invention.
  • a shut-off valve is dis­posed in the connection of the load sensing conduit to a said stroke control so that the pump, operatively connect­ed thereto, selectively does not undergo the said increase in displacement on the valve being closed.
  • a valve is provided to shut off the load sensing cir­cuit for at least one of the pumps, thereby causing the pump to destroke, at the option of the operator.
  • the excavator in Fig. 1 includes a main body 10 which has an operator's cab 12 at one end and which is mounted on an undercarriage 14 by means of a swing pivot 16.
  • the swing pivot is also schematically shown in Fig. 2, and the body 10 is rotatable through a full circle relative to the un­dercarriage 14 on the pivot 16, the swinging of the body being accomplished by a hydraulic motor 18 that drives a gear train 20 engageable with a large ring gear in the pi­vot mechanism to rotate the body 10.
  • the undercarriage 14 includes a pair of tracks 22 on oppo­site sides of the undercarriage, and the respective tracks are driven by hydraulic motors 24 and 25 through respective clutches 26 and 27 and planetary reduction gearing (not shown) in the well known manner.
  • the excavator includes a large boom 28 that extends from the body 10 and is swingable in a vertical arc by actua­tion of a pair of boom cylinders 30.
  • a dipper stick or arm 32 is swingably mounted on the outer end of the boom and its position is controlled by a hydraulic cylinder 34.
  • a conventional excavator bucket 36 At the lower end of the dipper stick or arm 32, there is mounted a conventional excavator bucket 36 that is swing­able relative to the arm 32 by means of a hydraulic cylin­der 38. All of the above represents more or less conven­tional construction, and the various hydraulic functions are all schematically shown on Fig. 2.
  • An internal combustion engine 40 is mounted in the body 10 and has an output shaft 42 that drives a pair of identical hydraulic pumps 44 and 46.
  • the pumps 44 and 46 are identi­cal variable displacement pumps and respectively have stroke control systems 48 and 50. While only two pumps are illustrated in the preferred embodiment, it is to be under­stood that three or more commonly driven and connected pumps could be included in the system. Since the stroke control system for the two pumps is essentially the same, only the stroke control system 48 for the pump 44 will be described in detail.
  • the displacement of the pump 44 is controlled by a stroke control cylinder 52 that is actuated by a change of pres­sure in a destroke line 54, the pressure in the line 54 acting against a spring in the stroke control cylinder 52 to destroke the pump.
  • the spring moves the piston of the stroke con­trol cylinder 52 toward full displacement of the pump.
  • the pump destroke line 54 is connected to a horsepower con­trol valve 56, which connects the line 54 to a load sens­ing spool valve 58 when the horsepower control valve 56 is in the position illustrated in Fig. 2.
  • the load sensing spool valve 58 in turn connects the destroke line 54 to a drain line 60 when the valve 58 is in the illustrated po­sition, and the drain line 60 is connected to a line 61 that dumps into the hydraulic systems reservoir 62.
  • the pumps 44 and 46 include inlet lines 64 that draw fluid from the reservoir 62 and also leakage lines 65 that dump pump leakage back to the reservoir 62.
  • the pump 44 has an outlet line 66 and the pump 46 has an outlet line 67 that are connected to a common outlet line 68, which is illu­strated in Fig. 2b, while the pumps and their respective controls are illustrated in Fig. 2a.
  • the outlet line 66 is connected to one end of the horsepower control valve 56 via a pilot line 70, and move­ment of the control valve 56 is caused by said pilot line pressure working against springs 72.
  • a load sensing line 74 is connected through a line 76 to the load sensing spool valve 58 for the pump 44 through an on-off type solenoid actuated valve 78 that is controlled by the operator by a conventional electric switch at the operator's cab 12.
  • the line 74 is connected to the load sensing spool valve for the control system 50 directly by a hydraulic line 80, so that the pressure in the load sens­ing line 74 is always communicated to one end of the load sensing spool valve for the pump 46 while it is optionally connected to the valve 58 for the other pump 44.
  • the pump Since the line 80 from the load sensing line 74 to the load sensing valve for the pump 46 is always connected to the valve, the pump responds to pressure in the load sens­ ing line 74 to place the pump in stroke when the pressure in the load sensing line 74 indicates a pressure demand.
  • the control system for the other motor 44 except that the operator by shifting the valve 78 to its closed condition, can shut off the con­nection of the load sensing line 74 to the valve 58, so that pressure in the line 66 shifts the valve 58 to con­nect the outlet line 66 to the pump destroke line 54, which thereby destrokes the pump.
  • the operator can optionally maintain the pump 44 in its destroked condition regardless of the demand indicated by the pressure in the load sensing line 74.
  • the common outlet line 68 for the two pumps serves as a common input for a bank of control valves 85, 86, 87, 88, 89 and 90 that respectively control the flow of pressuriz­ed fluid to, and exhaust fluid from, the boom cylinders 30, the arm cylinder 34, the bucket cylinder 38, the drive motor 24, the drive motor 25, and the swing control motor 18.
  • the valves 85 - 90 are essentially identical, and, therefore, only the valve 87 for the bucket control cylin­der 38 will be described in detail.
  • the valves are of the type known as load sensing control valves, and such valves are available from the Linde Hydraulics Company of Canfield, Ohio, United States of America as well as from others.
  • the valve 87 is connected to the common pump outlet line 68 by a hydraulic line 92 and a pair of load sensing lines 93 and 94 connect the valve to the main load sensing line 74.
  • a pair of drain lines 95 and 96 connect the valve to the main drain line 97 that connects the entire valve bank to the hydraulic reservoir 62 through an oil cooler 98 and an oil filter system 99, both of which are of known construction.
  • a relief valve system 200 is connected to the load sensing line 74 by a line 102 and to the common outlet line 68 by a line 194, the relief valve package being operable to dump the lines 102 and 104 to the reservoir line 97 when certain pressures are exceeded.
  • the valve 87 is connected to the bucket control cylinder by lines 106 and 108 and is shiftable in opposite direc­tions by means of pilot operated control systems 110 and 112, of known construction.
  • the pressurized inlet line 92 is connected to the valve outlet line 106, and the pressure directed to the cylinder 38 is also communicated to the load sensing line 93.
  • the other end of the cylinder is connected to the re­servoir through the line 108 and the valve 87.
  • the valve Conversely, when the valve is shifted in the opposite direction, it connects the pressure line 92 to the valve outlet line 108 while simultaneously communicating that pressure to the load sensing line 94, and the line 106 is connected to the reservoir via the drain line 95.
  • the swing motor 18 is provided with conventional check and pressure relief valves, and in addition to the control valves 88 and 89 for the track motors 24 and 25, metering valves 114 are provided to meter fluid to the respective motors. Since the present invention is not specifically directed to the hydraulic circuitry associated with the respective motors, the various relief and check valves are not described in detail.
  • the load sensing line 74 is also connected to a sensing line 116 that provides the input to a pressure actuated switch 118 of conventional construction.
  • a predetermined pressure in the load sensing system and consequently the pressure in line 116 operates to hold the switch 118 in an open condition.
  • a spring in the switch 118 closes the switch to connect the electrical system of the excavator to an automatic timer 120.
  • the timer is of known construc­tion and can be set to provide varying time delays, the preferable delay being in the range of 5 to 6 seconds.
  • the solenoid 122 is a dual coil type, the first or holding coil being immediately energized when the switch 118 closes, while the second coil, which causes the solenoid to shift against the bias of a spring 124, is energized only through the timer 120. Actuation of the solenoid 122 shifts a fuel injection pump lever 126 to throttle back the engine.
  • a manually actuated switch 128 is preferably provided in the electrical system to disconnect the system from the power source.
  • the excavator operator In operation, the excavator operator normally sets the en­gine throttle at a relatively high setting to provide ad­equate power to drive the pumps 44 and 46. If, however, the operator interrupts the operation of the machine, such as between truck loads, the entire control valve bank would be de-activated and the pressure in the load sensing line 74 would fall off. The reduced pressure would cause the pressure actuated switch 118 to close, and assuming that the switch 128 is closed to actuate the automatic idle system, electric energy would be directed to the timer 120. After the preset time delay, the power would be directed to the solenoid 122, to shift the solenoid and thereby throttle back the engine. Thus, after an appropriate inter­val when the hydraulic functions are not being operated, the engine is automatically throttled back to save on en­gine wear and fuel. Obviously, the operator can de-activate the automatic idle system by simply opening the switch 128.
  • valve 78 in operation, the operator normally maintains the valve 78 in its open condition, as shown. As previously described, this allows load sensing pressure to be suppli­ ed to both pump displacement control systems 48 and 50 so that the displacement of both pumps 44 and 46 increases in response to load. However, if the operator wishes to re­duce the flow rate of the system and thereby provide finer control of the various motors, he simply closes the valve 78 so that the load sensing pressure is not applied to the control system 48 for the motor 44, whereby the motor 44 is maintained at minimum displacement.

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  • Engineering & Computer Science (AREA)
  • General Engineering & Computer Science (AREA)
  • Mining & Mineral Resources (AREA)
  • Civil Engineering (AREA)
  • Structural Engineering (AREA)
  • Physics & Mathematics (AREA)
  • Fluid Mechanics (AREA)
  • Mechanical Engineering (AREA)
  • Operation Control Of Excavators (AREA)
  • Fluid-Pressure Circuits (AREA)
EP19880102009 1987-02-19 1988-02-11 Système hydraulique pour un engin de terrassement Expired EP0279356B1 (fr)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
US1631987A 1987-02-19 1987-02-19
US16319 1987-02-19

Publications (2)

Publication Number Publication Date
EP0279356A1 true EP0279356A1 (fr) 1988-08-24
EP0279356B1 EP0279356B1 (fr) 1991-05-22

Family

ID=21776542

Family Applications (1)

Application Number Title Priority Date Filing Date
EP19880102009 Expired EP0279356B1 (fr) 1987-02-19 1988-02-11 Système hydraulique pour un engin de terrassement

Country Status (4)

Country Link
EP (1) EP0279356B1 (fr)
JP (1) JP2589736B2 (fr)
CA (1) CA1278978C (fr)
DE (1) DE3862874D1 (fr)

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0353799A1 (fr) * 1988-07-04 1990-02-07 Hitachi Construction Machinery Co., Ltd. Dispositif pour régler la vitesse de rotation d'un engin de terrassement
EP0518345A1 (fr) * 1991-06-14 1992-12-16 Fuji Jukogyo Kabushiki Kaisha Système de commande hydraulique pour avion
EP0797009A2 (fr) * 1996-03-22 1997-09-24 Trinova Limited Circuit de commande de fluide

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN104500481B (zh) * 2014-12-31 2017-10-31 中联重科股份有限公司 负载敏感控制系统及其控制方法和具有该系统的液压设备

Citations (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR1555395A (fr) * 1967-03-10 1969-01-24
FR2103965A5 (fr) * 1970-08-05 1972-04-14 Rauch Constantin
FR2111406A5 (fr) * 1970-10-24 1972-06-02 Rheinstahl Ag
US4017215A (en) * 1976-03-15 1977-04-12 Caterpillar Tractor Co. Infinitely variable orifice for part throttle control
FR2383816A1 (fr) * 1977-03-17 1978-10-13 Caterpillar Tractor Co Installation de commande a fluide avec circuits de priorite
EP0071228A2 (fr) * 1981-07-24 1983-02-09 Hitachi Construction Machinery Co., Ltd. Système de régulation pour dispositif de circuit hydraulique
EP0232683A1 (fr) * 1986-02-04 1987-08-19 TRINOVA S.p.A. Système de contrôle hydraulique pour éléments de travail de machines de terrassement ayant un système centralisé de freinage pour les dispositifs d'entraînement
EP0235545A2 (fr) * 1986-01-25 1987-09-09 Hitachi Construction Machinery Co., Ltd. Système hydraulique d'entraînement

Family Cites Families (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS58213927A (ja) * 1982-06-07 1983-12-13 Daikin Ind Ltd パワ−シヨベル等の建設機械

Patent Citations (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR1555395A (fr) * 1967-03-10 1969-01-24
FR2103965A5 (fr) * 1970-08-05 1972-04-14 Rauch Constantin
FR2111406A5 (fr) * 1970-10-24 1972-06-02 Rheinstahl Ag
US4017215A (en) * 1976-03-15 1977-04-12 Caterpillar Tractor Co. Infinitely variable orifice for part throttle control
FR2383816A1 (fr) * 1977-03-17 1978-10-13 Caterpillar Tractor Co Installation de commande a fluide avec circuits de priorite
EP0071228A2 (fr) * 1981-07-24 1983-02-09 Hitachi Construction Machinery Co., Ltd. Système de régulation pour dispositif de circuit hydraulique
EP0235545A2 (fr) * 1986-01-25 1987-09-09 Hitachi Construction Machinery Co., Ltd. Système hydraulique d'entraînement
EP0232683A1 (fr) * 1986-02-04 1987-08-19 TRINOVA S.p.A. Système de contrôle hydraulique pour éléments de travail de machines de terrassement ayant un système centralisé de freinage pour les dispositifs d'entraînement

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0353799A1 (fr) * 1988-07-04 1990-02-07 Hitachi Construction Machinery Co., Ltd. Dispositif pour régler la vitesse de rotation d'un engin de terrassement
EP0518345A1 (fr) * 1991-06-14 1992-12-16 Fuji Jukogyo Kabushiki Kaisha Système de commande hydraulique pour avion
EP0797009A2 (fr) * 1996-03-22 1997-09-24 Trinova Limited Circuit de commande de fluide
EP0797009A3 (fr) * 1996-03-22 1999-06-23 Trinova Limited Circuit de commande de fluide

Also Published As

Publication number Publication date
CA1278978C (fr) 1991-01-15
JP2589736B2 (ja) 1997-03-12
EP0279356B1 (fr) 1991-05-22
JPS63217025A (ja) 1988-09-09
DE3862874D1 (de) 1991-06-27

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