EP0684387B1 - Système de commande hydraulique de détection de la charge - Google Patents

Système de commande hydraulique de détection de la charge Download PDF

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Publication number
EP0684387B1
EP0684387B1 EP95202286A EP95202286A EP0684387B1 EP 0684387 B1 EP0684387 B1 EP 0684387B1 EP 95202286 A EP95202286 A EP 95202286A EP 95202286 A EP95202286 A EP 95202286A EP 0684387 B1 EP0684387 B1 EP 0684387B1
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EP
European Patent Office
Prior art keywords
pressure
change
valve
load
pilot
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
EP95202286A
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German (de)
English (en)
Other versions
EP0684387A3 (fr
EP0684387A2 (fr
Inventor
Hideshi Koiwai
Hisato Naito
Yoshitake Yonekubo
Kenichi Nishiumi
Yoshimi Hasegawa
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KYB Corp
Original Assignee
Kayaba Industry 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
Priority claimed from JP03357128A external-priority patent/JP3124094B2/ja
Priority claimed from JP21224492A external-priority patent/JPH0633904A/ja
Priority claimed from JP04250517A external-priority patent/JP3128775B2/ja
Application filed by Kayaba Industry Co Ltd filed Critical Kayaba Industry Co Ltd
Publication of EP0684387A2 publication Critical patent/EP0684387A2/fr
Publication of EP0684387A3 publication Critical patent/EP0684387A3/fr
Application granted granted Critical
Publication of EP0684387B1 publication Critical patent/EP0684387B1/fr
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

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    • E—FIXED CONSTRUCTIONS
    • E02—HYDRAULIC ENGINEERING; FOUNDATIONS; SOIL SHIFTING
    • E02F—DREDGING; SOIL-SHIFTING
    • E02F9/00—Component parts of dredgers or soil-shifting machines, not restricted to one of the kinds covered by groups E02F3/00 - E02F7/00
    • E02F9/20—Drives; Control devices
    • E02F9/22—Hydraulic or pneumatic drives
    • E02F9/2221—Control of flow rate; Load sensing arrangements
    • 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
    • E02F9/2225—Control of flow rate; Load sensing arrangements using pressure-compensating valves
    • 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
    • F15B11/162—Servomotor systems without provision for follow-up action; Circuits therefor with two or more servomotors with sensing of servomotor demand or load for giving priority to particular servomotors or users
    • 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
    • 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
    • F15B11/166—Controlling a pilot pressure in response to the load, i.e. supply to at least one user is regulated by adjusting either the system pilot pressure or one or more of the individual pilot command pressures
    • 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
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
    • F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
    • F15B2211/00—Circuits for servomotor systems
    • F15B2211/30—Directional control
    • F15B2211/305—Directional control characterised by the type of valves
    • F15B2211/30525—Directional control valves, e.g. 4/3-directional control valve
    • F15B2211/3053—In combination with a pressure compensating valve
    • F15B2211/30555—Inlet and outlet of the pressure compensating valve being connected to the directional control valve
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
    • F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
    • F15B2211/00—Circuits for servomotor systems
    • F15B2211/30—Directional control
    • F15B2211/32—Directional control characterised by the type of actuation
    • F15B2211/329—Directional control characterised by the type of actuation actuated by fluid pressure
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
    • F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
    • F15B2211/00—Circuits for servomotor systems
    • F15B2211/40—Flow control
    • F15B2211/405—Flow control characterised by the type of flow control means or valve
    • F15B2211/40576—Assemblies of multiple valves
    • F15B2211/40584—Assemblies of multiple valves the flow control means arranged in parallel with a check valve
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
    • F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
    • F15B2211/00—Circuits for servomotor systems
    • F15B2211/40—Flow control
    • F15B2211/46—Control of flow in the 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
    • F15B2211/40—Flow control
    • F15B2211/47—Flow control in one direction only
    • F15B2211/473—Flow control in one direction only without restriction in the reverse direction
    • 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
    • F15B2211/50518—Pressure control characterised by the type of pressure control means the pressure control means controlling a pressure upstream of the pressure control means using pressure relief 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
    • F15B2211/50—Pressure control
    • F15B2211/515—Pressure control characterised by the connections of the pressure control means in the circuit
    • F15B2211/5153—Pressure control characterised by the connections of the pressure control means in the circuit being connected to an output member and a directional control valve
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
    • F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
    • F15B2211/00—Circuits for servomotor systems
    • F15B2211/50—Pressure control
    • F15B2211/55—Pressure control for limiting a pressure up to a maximum pressure, e.g. by using a pressure relief valve
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
    • F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
    • F15B2211/00—Circuits for servomotor systems
    • F15B2211/50—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
    • F15B2211/635—Circuits providing pilot pressure to pilot pressure-controlled fluid circuit elements
    • F15B2211/6355—Circuits providing pilot pressure to pilot pressure-controlled fluid circuit elements having valve means
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
    • F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
    • F15B2211/00—Circuits for servomotor systems
    • F15B2211/60—Circuit components or control therefor
    • F15B2211/65—Methods of control of the load sensing pressure
    • F15B2211/654—Methods of control of the load sensing pressure the load sensing pressure being lower than the 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
    • F15B2211/70—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 load-sensing active hydraulic control device, and more particularly to a load-sensing active hydraulic control device for detecting a load pressure of a plurality of hydraulic actuators to keep an output of a pump constant.
  • a load-sensing active hydraulic control device which comprises a tank, a plurality of actuators provided with pressure lines and change-over valves connected in parallel, respectively, pilot chambers provided on both sides of each of the change-over valves which are provided with variable orifices of which a degree of opening is controlled depending on a pressure in the pilot chambers, a pressure compensating valve provided on a downstream side of the variable orifices of each of the change-over valves for keeping a pressure difference between a load pressure and a pressure on the downstream side of the variable orifices constant, overload relief valves connected to the downstream side of each of said switching valves for setting a maximum pressure of each of said actuators, and a pump output control mechanism arranged so as to keep an output of a pump constant in response to a load pressure of each of the actuators.
  • the load-sensing active hydraulic control device of the present invention thus generally constructed is characterised in that a pilot valve is provided so as to permit at least one of the pilot chambers of at least one of the change-over valves to communicate with the tank when the load pressure in at least one of the pressure lines of at least one of the actuators is equal to or approaches a set pressure of the overload relief valve.
  • the pressure when a load pressure of any one of the actuators is increased to a level equal to or approaching a set pressure of the overload relief valve, the pressure causes the pilot valve to be open, thereby to permit the pilot chambers of the change-over valve to communicate with the tank.
  • Such communication between the pilot chambers and the tank causes the change-over valve to return to the neutral position or a position approaching the neutral position, resulting in a degree of opening of the variable orifices being reduced.
  • This permits a degree of opening of the variable orifices of the change-over valve connected to the one actuator to be increased as compared with a degree of opening of the variable orifices of the change-over valve connected to the other actuator.
  • the ratio between both degrees of opening is increased, so that the amount of hydraulic fluid distributed to the other actuator is increased, even when the amount of hydraulic fluid discharged from the variable discharge pump is constant, resulting in feeding of hydraulic fluid to the other actuator being ensured.
  • a load-sensing active hydraulic control device which has been conventionally known in the art will now be described hereinafter with reference to Figure 2.
  • a variable discharge pump 1 is connected on a discharge side thereof to a high pressure passage 2 and then connected through the high pressure passage 2 to an inlet port 5 of each of a first change-over valve 3 and a second change-over valve 4.
  • the first change-over valve 3 is provided on each side thereof with a respective pilot chamber 3a, 3b and the second change-over valve 4 is likewise provided on each side thereof with a respective pilot chamber 4a, 4b.
  • the pilot chambers 3a and 3b are connected to a pilot operating valve V1 and likewise the pilot chambers 4a and 4b are connected to a pilot operating valve V2.
  • the pilot operating valves V1 and V2 are each adapted to control an output pilot pressure depending on the amount of operation thereof.
  • Each change-over valve 3, 4 when at a neutral position as shown in Figure 1, has its inlet port 5 closed.
  • a variable orifice 6 is rendered open and the degree of opening of the variable orifice 6 is controlled depending on the amount of changing-over of the valve.
  • variable orifice 6 is connected on a downstream side thereof through a check valve 7 to a pressure compensating valve 8. Further, the pressure compensating valve 8 is arranged so as to communicate on a downstream side thereof with a feed port 9 of each of the change-over valves 3 and 4.
  • the feed ports 9 are kept closed when the corresponding change-over valve 3 or 4 is at a neutral position and permitted to communicate with any one of actuator ports 10 and 11 when the change-over valves 3 and 4 are changed over to either a left-side position or a right-side position. At this time, the other of the actuator ports 10 and 11 is kept communicating with a tank passage 12.
  • the change-over valves 3 and 4 are each formed with a load detecting port 13, which is arranged so as to communicate with the actuator port on a high pressure side.
  • the above-described pressure compensating valve 8 functions to introduce a pressure on an upstream side of the check valve 7 into a pilot chamber 8a, as well as a pressure on a side of the load detecting port 13 into a pilot chamber 8b.
  • a plurality of shuttle valves 14 are arranged so as to select a maximum load pressure of the actuators controlled by the change-over valves 3 and 4 to introduce it to the pilot chambers 8b.
  • Control by the pressure compensating valve 8 thus constructed is carried out in such a manner that a pressure on a downstream side of the variable orifice 6 is kept increased by a predetermined level as compared with the maximum load pressure.
  • the maximum load pressure selected by the shuttle valves 14 is fed to one pilot chamber 15a of a control valve 15.
  • the other pilot valve 15b of the control valve 15 is fed with a pressure in the above-described high pressure passage 2 or a discharge pressure of the variable discharge pump 1.
  • operation of the control valve 15 is carried out depending on a relative difference between the discharge pressure of the variable discharge pump 1 and the maximum load pressure.
  • Such operation of the control valve 15 causes a control cylinder 16 constituting a pump output control mechanism for keeping an output of the variable discharge pump 1 constant to be operated, thereby to ensure that the discharge pressure of the variable discharge pump 1 is kept constantly increased by a predetermined level as compared with the maximum load pressure.
  • the above-described change-over valves 3 and 4 are connected at the actuator ports 10 and 11 thereof through lines (passages) 17 and 18 to overload relief valves 21 and 22, respectively.
  • Reference numeral 23 designates a main relief valve.
  • operation of the pilot operating valves V1 and V1 causes the pilot pressure to act on any one of the pilot chambers 3b and 4b of the change-over valves 3 and 4. Supposing that the valves are operated to cause the pilot pressure to act on the pilot chambers 3b and 4b, the change-over valves 3 and 4 are changed over to the right-side position.
  • a degree of opening of each of the variable orifices 6 is set depending on the amount of changing-over of each of the change-over valves 3 and 4 and hydraulic oil or fluid discharged from the variable discharge pump 1 is distributed depending on a ratio of a degree of opening of the variable orifice 6 of the change-over valve 3 to that of the change-over valve 4.
  • hydraulic fluid is fed to bottom-side chambers 19a and 20a of the cylinders 19 and 20 through lines (passages) 18 depending on a degree of opening of the change-over valves 3 and 4.
  • Hydraulic fluid on a side upper or rod-side chambers 19b and 20b of the cylinders 19 and 20 is returned via lines (passages) 17 through the change-over valves 3 and 4 to the tank passage 12.
  • the maximum load pressure of the actuators acts on the control cylinder 16 to control the amount of hydraulic fluid discharged from the pump 1. More particularly, the control is carried out so as to permit a product of Q x P to be fixed as shown in Figure 3, wherein P is a pressure of the variable discharge pump 1 and Q is the amount of hydraulic fluid discharged from the variable discharge pump 1. Therefore, the more the maximum load pressure is increased, the more the amount of hydraulic fluid discharged from the variable discharge pump 1 is decreased. Hydraulic fluid of which the amount is thus reduced is distributed depending on a ratio between a degree of opening of the variable orifice 6 of the change-over valve 3 and that of the change-over valve 4.
  • the conventional device as described above, is adapted to control a discharge pressure of the variable discharge pump 1 by the action of the maximum one of load pressures of a plurality of actuators, resulting in often failing to actuate the actuators.
  • one pilot chamber 4b of a change-over valve 4 is connected to a tank T through a pilot valve 25 connected to a pilot passage 24 from chamber 4b.
  • the pilot valve 25 is so constructed that elastic force of a spring 26 acts on one side of the pilot valve 25 and a pressure in the line (passage) 18 acts on a pilot chamber 27 provided on the other side of the pilot valve 25.
  • the pilot valve 25 thus constructed is rendered open when the pressure in the line (passage) 18 or a load pressure of a cylinder 20 approaches a set pressure of an overload relief valve 22.
  • pilot valve 25 When the pilot valve 25 is at a normal position shown in Figure 1, it closes the pilot passage 24. Changing-over of the pilot valve 25 causes the pilot chamber 4b of the change-over valve 4 to communicate with the tank.
  • the remaining part of the illustrated embodiment may be constructed in substantially the same manner as the conventional device described above.
  • a full stroke of the cylinder 20 causes an increase in load, thereby to generate a pressure, which causes the pilot valve 25 to be open.
  • Such opening of the pilot valve 25 causes the pilot chamber 4b of the change-over valve 4 to communicate with the tank T, resulting in the action by the pressure being decreased, so that the change-over valve 4 is changed over toward a neutral position correspondingly.
  • a degree of opening of the variable orifice 6 of the change-over valve 4 is reduced to decrease the amount of hydraulic fluid fed to the cylinder 20 correspondingly.
  • variable orifice 6 of the change-over valve 4 when a degree of opening of the variable orifice 6 of the change-over valve 4 is low as compared with that of the variable orifice 6 of the change-over valve 3, hydraulic fluid discharged from the variable discharge pump 1 is distributed depending on a ratio between both degrees of opening, resulting in hydraulic fluid being fed to the cylinder 19 connected to the change-over valve 3 as well.
  • the pilot valve 25 is connected to only the line (passage) 18 connected to a bottom-side chamber 20a of the cylinder 20.
  • the pilot valve 25 may be connected to only a line (passage) 17 or to both lines (passages) 17 and 18.
  • the device of the illustrated embodiment constructed as described above ensures feed of hydraulic fluid to the other cylinder 19 even when a load pressure on the side of the cylinder 20 is increased to a level approaching a set pressure of the overload relief valve, thereby to prevent actuation of the cylinder 19 from being stopped.
  • the load-sensing active hydraulic control device of the present invention effectively prevents, even when a load pressure of any one of the actuators is increased to a level equal to or approaching the set pressure of the overload relief valve, the amount of hydraulic fluid fed to the other actuator from being extremely reduced. This eliminates such a problem as encountered with the prior art that actuation of the outer actuator is stopped.

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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)
  • Operation Control Of Excavators (AREA)

Claims (1)

  1. Dispositif hydraulique de commande actif à détection de charge comportant un réservoir (T), une pluralité de dispositifs d'actionnement (19, 20) pourvus de conduites de pression (17, 18) et de soupapes de commutation (3, 4) reliées en parallèle, des chambres pilotes (3a, 3b, 4a, 4b) prévues des deux côtés de chacune des soupapes de commutation (3, 4), les soupapes de commutation (3, 4) étant pourvues chacune d'orifices variables (6) dont un degré d'ouverture est commandé en fonction d'une pression dans les chambres pilotes (3a, 3b, 4a, 4b), une soupape de compensation de pression (8) prévue sur un côté aval des orifices variables (6) de chacune des soupapes de commutation (3, 4) afin de maintenir constante une différence de pression entre une pression de charge et une pression du côté aval des orifices variables (6), des soupapes de sécurité de surcharge (21, 22) reliées au côté aval de chacun desdits dispositifs d'actionnement (19, 20), et un mécanisme de commande de sortie de pompe (16) prévu pour maintenir constante une sortie d'une pompe (1) en réponse à une pression de charge de chacun des dispositifs d'actionnement (19, 20), caractérisé en ce que une soupape pilote (25) est prévue afin de permettre à au moins une des chambres pilotes (3a, 3b, 4a, 4b) d'au moins une des soupapes de commutation (3, 4) de communiquer avec le réservoir (T) quand la pression de charge dans au moins une des conduites de pression (17, 18) d'au moins un des dispositifs d'actionnement (19, 20) est égale à ou s'approche d'une pression réglée de la soupape de sécurité de surcharge (22).
EP95202286A 1991-12-25 1992-12-23 Système de commande hydraulique de détection de la charge Expired - Lifetime EP0684387B1 (fr)

Applications Claiming Priority (10)

Application Number Priority Date Filing Date Title
JP35712891 1991-12-25
JP357128/91 1991-12-25
JP03357128A JP3124094B2 (ja) 1991-12-25 1991-12-25 複数アクチュエータの制御装置
JP21224492 1992-07-16
JP212244/92 1992-07-16
JP21224492A JPH0633904A (ja) 1992-07-16 1992-07-16 負荷感応形制御装置
JP25051792 1992-08-26
JP250517/92 1992-08-26
JP04250517A JP3128775B2 (ja) 1992-08-26 1992-08-26 負荷感応形制御装置
EP19920311770 EP0550257B1 (fr) 1991-12-25 1992-12-23 Dispositif de commande pour plusieurs servomoteurs

Related Parent Applications (2)

Application Number Title Priority Date Filing Date
EP19920311770 Division EP0550257B1 (fr) 1991-12-25 1992-12-23 Dispositif de commande pour plusieurs servomoteurs
EP92311770.9 Division 1992-12-23

Publications (3)

Publication Number Publication Date
EP0684387A2 EP0684387A2 (fr) 1995-11-29
EP0684387A3 EP0684387A3 (fr) 1996-10-30
EP0684387B1 true EP0684387B1 (fr) 1999-09-08

Family

ID=27329339

Family Applications (4)

Application Number Title Priority Date Filing Date
EP95202287A Expired - Lifetime EP0684389B1 (fr) 1991-12-25 1992-12-23 Système de commande pour appareil hydraulique avec plusieurs consommateurs
EP19920311770 Expired - Lifetime EP0550257B1 (fr) 1991-12-25 1992-12-23 Dispositif de commande pour plusieurs servomoteurs
EP95202286A Expired - Lifetime EP0684387B1 (fr) 1991-12-25 1992-12-23 Système de commande hydraulique de détection de la charge
EP95202288A Expired - Lifetime EP0684388B1 (fr) 1991-12-25 1992-12-23 Système de commande hydraulique de détection de la charge

Family Applications Before (2)

Application Number Title Priority Date Filing Date
EP95202287A Expired - Lifetime EP0684389B1 (fr) 1991-12-25 1992-12-23 Système de commande pour appareil hydraulique avec plusieurs consommateurs
EP19920311770 Expired - Lifetime EP0550257B1 (fr) 1991-12-25 1992-12-23 Dispositif de commande pour plusieurs servomoteurs

Family Applications After (1)

Application Number Title Priority Date Filing Date
EP95202288A Expired - Lifetime EP0684388B1 (fr) 1991-12-25 1992-12-23 Système de commande hydraulique de détection de la charge

Country Status (2)

Country Link
EP (4) EP0684389B1 (fr)
DE (4) DE69229968T2 (fr)

Families Citing this family (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE19719228A1 (de) * 1997-05-07 1998-11-12 Bosch Gmbh Robert Hydraulische Steuereinrichtung zur lastdruckunabhängigen Steuerung eines doppeltwirkenden Motors
DE19831595B4 (de) * 1998-07-14 2007-02-01 Bosch Rexroth Aktiengesellschaft Hydraulische Schaltung
FR2807118B1 (fr) * 2000-03-28 2002-07-05 Mannesmann Rexroth Sa Circuit hydraulique pour l'actionnement de recepteurs hydrauliques multiples
EP2635747B1 (fr) * 2010-11-01 2019-09-25 Volvo Construction Equipment AB Procédé pour commander un système hydraulique d'une machine à travailler
CN104627880B (zh) * 2014-12-31 2017-02-22 中联重科股份有限公司 闭式系统、控制方法、卷扬系统和履带式车辆行走系统
CN110671376B (zh) * 2019-09-29 2021-03-12 中国矿业大学 工程机械负载敏感-进出口独立液压系统及其控制方法

Family Cites Families (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE3710699C1 (de) * 1987-03-31 1988-08-18 Heilmeier & Weinlein Hydraulische Steuervorrichtung fuer eine Verbrauchergruppe
SE8803181D0 (sv) * 1988-09-09 1988-09-09 Atlas Copco Ab Hydraulic driving system with a priority function for hydraulic motors
WO1990014519A1 (fr) * 1989-05-24 1990-11-29 Kabushiki Kaisha Komatsu Seisakusho Appareil a circuit hydraulique

Also Published As

Publication number Publication date
DE69225392T2 (de) 1998-09-03
DE69229966D1 (de) 1999-10-14
EP0684388A2 (fr) 1995-11-29
EP0684388B1 (fr) 1999-02-24
DE69228489D1 (de) 1999-04-01
DE69228489T2 (de) 1999-09-30
EP0550257A1 (fr) 1993-07-07
EP0684389A2 (fr) 1995-11-29
DE69229968T2 (de) 2000-03-09
DE69229966T2 (de) 2000-03-09
EP0684387A3 (fr) 1996-10-30
EP0550257B1 (fr) 1998-05-06
EP0684388A3 (fr) 1996-11-06
EP0684389B1 (fr) 1999-09-08
EP0684387A2 (fr) 1995-11-29
EP0684389A3 (fr) 1996-10-30
DE69229968D1 (de) 1999-10-14
DE69225392D1 (de) 1998-06-10

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