EP0550257A1 - Einrichtung zur Steuerung mehrerer Servomotoren - Google Patents
Einrichtung zur Steuerung mehrerer Servomotoren Download PDFInfo
- Publication number
- EP0550257A1 EP0550257A1 EP92311770A EP92311770A EP0550257A1 EP 0550257 A1 EP0550257 A1 EP 0550257A1 EP 92311770 A EP92311770 A EP 92311770A EP 92311770 A EP92311770 A EP 92311770A EP 0550257 A1 EP0550257 A1 EP 0550257A1
- Authority
- EP
- European Patent Office
- Prior art keywords
- pressure
- actuators
- valve
- load
- switching
- 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.)
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Classifications
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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
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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
- E02F9/2225—Control of flow rate; Load sensing arrangements using pressure-compensating valves
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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
- E02F9/2278—Hydraulic circuits
- E02F9/2296—Systems with a variable displacement pump
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
- F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
- F15B11/00—Servomotor systems without provision for follow-up action; Circuits therefor
- 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
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
- F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
- F15B11/00—Servomotor systems without provision for follow-up action; Circuits therefor
- 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
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
- F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
- F15B11/00—Servomotor systems without provision for follow-up action; Circuits therefor
- 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
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
- F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
- 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
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
- F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
- F15B2211/00—Circuits for servomotor systems
- F15B2211/20—Fluid pressure source, e.g. accumulator or variable axial piston pump
- F15B2211/25—Pressure control functions
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
- F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
- 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
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
- F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
- 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
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
- F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
- 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
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
- F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
- F15B2211/00—Circuits for servomotor systems
- F15B2211/40—Flow control
- F15B2211/46—Control of flow in the return line, i.e. meter-out control
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
- F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
- 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
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
- F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
- 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
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
- F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
- 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
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
- F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
- 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
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
- F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
- F15B2211/00—Circuits for servomotor systems
- F15B2211/50—Pressure control
- F15B2211/575—Pilot pressure control
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
- F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
- 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
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
- F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
- 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
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
- F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
- 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
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
- F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
- 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
- the present invention relates to a device for controlling multiple hydraulic actuators, and, more particularly, to a device for controlling multiple hydraulic actuators to protect a system from an overpressure caused by increasing the load on an individual actuator.
- the present invention can be applied, for example, to such a system as a power shovel that operates such multiple actuators as a spin motor, a boom cylinder, an arm cylinder, a bucket cylinder, and a driving motor.
- An object of the present invention is to provide a device for controlling multiple actuators that overcomes the drawbacks of the prior-art device.
- a further object of the present invention is to provide a device for controlling multiple actuators where the fluid drained from the variable drain pump is not lost, so that all actuators can continue to work even when their load pressure rises.
- the present invention provides a device for controlling multiple hydraulic actuators to protect a system from an overpressure caused by increasing the load on an individual actuator.
- the device of the present invention prevents the shutdown of the device caused by too much fluid going to the actuator operating at the maximum pressure. Thus all actuators continue to operate even if one is overpressured.
- a load-sensing active hydraulic control device comprises: a tank for containing hydraulic fluid; a plurality of actuators; a pump connecting to the plurality of actuators and to the tank; the pump being effective for pumping the hydraulic fluid; each of the plurality of actuators having at least two switching valves respectively; the at least two switching valves being connected in parallel; each of the at least two switching valves having at least one pilot chamber; each of the at least two switching valves having at least one variable orifice; the at least one variable orifice being open an amount responsive to a pressure in the at least one pilot chamber; a pressure compensating valve being connected to the at least one variable orifice, whereby a pressure difference is maintained between a load pressure on a one of the plurality of actuators and a pressure on a lower portion of the at least variable orifice; at least one overload relief valve connected to a lower portion of each of the at least two switching valves, whereby a maximum pressure is fixed for the plurality of actuators; and means
- a control device for multiple hydraulic actuators comprises: a tank for containing hydraulic fluid; a plurality of actuators; a pump connecting to the plurality of actuators and to the tank; the pump being effective for pumping the hydraulic fluid; each of the plurality of actuators having at least at least one switching valve; each of the at least one switching valve having at least one variable orifice; each of the at least one switching valve being disposed to assume a one of a plurality of positions; means responsive to the at least one variable orifice for controlling a supply of the hydraulic fluid between a fluid supply course and at least one of the plurality of actuators according to the one of the plurality of positions of the at least one switching valve; a pressure compensating valve being connected to the at least one variable orifice, whereby a pressure difference is maintained between a load pressure on a one of the plurality of actuators and a pressure on a lower portion of the at least one variable orifice; means for controlling a drain pressure of the pump, whereby the drain pressure is
- a load-sensing active control device comprises; a tank for containing hydraulic fluid; a plurality of actuators; a pump connecting to the plurality of actuators and to the tank; the pump being effective for pumping the hydraulic fluid; each of the plurality of actuators having at least two switching valves respectively; the at least two switching valves being connected in parallel; each of the at least two switching valves having at least one variable orifice; each of the at least two switching valves being disposed to assume a one of a plurality of positions; the at least one variable orifice being open an amount responsive to the one of the plurality of positions; a pressure compensating valve being connected to the at least one variable orifice, whereby a pressure difference is maintained between a load pressure on a one of said plurality of actuators and a pressure on a lower portion of the at least one variable orifice; a load-detecting fluid course being connected with a shuttle valve to detect a load pressure on each of the plurality of actuators; means for transferring
- Fig. 1 is a circuit diagram of the control device of the prior art.
- Fig. 2 is a graph showing the relationship of P (pressure) to Q (quantity of fluid) in a variable drain pump.
- Fig. 3 is a circuit diagram of a first embodiment of the present invention.
- Fig. 4 is a circuit diagram of a second embodiment of the present invention.
- Fig. 5 is a graph showing the relationship of P to Q in the second embodiment of the present invention.
- Fig. 6 is a circuit diagram of a third embodiment of the present invention.
- Fig. 7 is a circuit diagram of a fourth embodiment of the present invention.
- a variable drain pump 1 is connected to a pair of ports 5,5, each associated respectively with a first switching valve 3 or a second switching valve 4 through a high pressure fluid course 2.
- Each of a pair of pilot chambers 3a, 3b and 4a, 4b are respectively attached at opposite sides of each of switching valves 3 and 4 and coupled to pilot operating valves V1 and V2, whereby pilot operating valves V1 and V2 control an output pilot pressure.
- Switching valves 3 and 4 are normally in a neutral position and ports 5,5 are closed. Switching valves 3 and 4 are each associated with a pair of variable orifices 6, 6'. Placing either of switching valves 3 or 4 in either a left or a right position opens the pair of variable orifices 6, 6' associated with that valve. The opening of the pair of variable orifices 6, 6' is proportional to the setting of the valve.
- each pair of variable orifices 6, 6' is a pressure compensating valve 8 connected through a check valve 7.
- Each of switching valves 3 and 4 has a supply port 9 that connects to the lower side of pressure compensating valve 8. Supply ports 9, 9 are closed when switching valves 3 and 4 are at a neutral position. Moving switching valves 3, 4 to either a left or a right position couples supply ports 9,9 with either of a pair of actuator ports 10, 11 and connects the other actuator port with a tank fluid course 12.
- a pair of load detecting ports 13, 13 attached to switching valves 3 and 4 is connected with tank fluid course 12 when switching valves 3 and 4 are in a neutral position.
- each of load detecting ports 13 is connected to the actuator port 10, 11 with the higher pressure.
- Pressure compensating valves 8, 8 equalize the respective pressures of the upper side of check valves 7, 7 to that of pilot chambers 8a, 8a and the respective pressures of load detecting ports 13, 13 to that of pilot chambers 8b, 8b.
- a shuttle valve 14 transfers to pilot chamber 8b the highest pressure of any one among the actuators controlled by switching valves 3 and 4.
- Pressure compensating valve 8 operates at the pressure of the lower of the pair of variable orifices 6, 6', that is, at a fixed-rate higher than the maximum load pressure.
- the maximum load pressure chosen by shuttle valve 14 is transferred to a pilot chamber 15a of a control valve 15, and a pilot chamber 15b has the pressure of high pressure fluid course 2 or the pressure of variable drain pump 1.
- the difference between the pressure of variable drain pump 1 and the maximum load pressure actuates control valve 15.
- Control valve 15 operates control cylinder 16, which runs at constant power, to keep the pressure from variable drain pump 1 at a fixed rate higher than the maximum load pressure.
- Each pair of actuator ports 10 and 11 of switching valves 3 and 4 is connected respectively to a pair of cylinders 19 and 20 through a pair of fluid courses 17 and 18 to which each of a pair of overload relief valves 21 and 22 are connected.
- pilot operating valves V1 and V2 supply a pilot pressure to either pilot chambers 3a, 3b of switching valve 3 or pilot chambers 4a, 4b of switching valve 4.
- pilot pressure from pilot chamber 3b shifts switching valve 3 to the right position.
- pilot pressure from pilot chamber 4b shifts switching valve 4 to the right position.
- variable drain pump 1 supplies amounts of fluid under pressure that correspond to the ratio of each pair of variable orifices.
- the fluid is supplied to bottom chambers 19a and 20a of cylinders 19 and 20 or to individual actuators.
- the fluid in rod chambers 19b, 20b returns to tank fluid course 12 through switching valves 3 and 4.
- Control cylinder 16 controls the quantity of fluid from pump 1 according to the maximum load pressure on any one among the actuators.
- variable drain pump 1 depends on the product of the pressure P and a quantity of fluid Q, which product is fixed. Thus the higher the maximum load pressure, the less the amount of fluid drained from variable drain pump 1. The amount drained corresponds to the ratio of the pair of variable orifices 6, 6' of either switching valve 3 or switching valve 4.
- variable drain pump 1 since the drain pressure of variable drain pump 1 is controlled by the maximum load pressure on multiple actuators, a difficulty can arise in its operation.
- cylinder 20 makes a full stroke.
- the load increases so that either overload relief valve 21 or overload relief valve 22, each connected to cylinder 20, opens.
- the amount of fluid that drains from variable drain pump 1 decreases, according to the curve of Fig. 2, since the amount of power is fixed. Therefore the supply of fluid to switching valve 3 is reduced, and, in the worst case, cylinder 19 comes to a complete stop.
- a pilot chamber 4b of a switching valve 4 is connected to a pilot valve 25 through a pilot course 24 that extends into a tank T.
- Pilot valve 25 has a spring 26 at one side.
- a pilot chamber 27 is coupled to a fluid course 18 so that both have the same pressure. Pilot valve 25 is opened when the pressure of fluid course 18, or the load pressure of a cylinder 20, opens an overload relief valve 22.
- pilot chamber 4b of switching valve 4 can be controlled by switching pilot valve 25.
- pilot course 24 is closed.
- Pilot course 24 contains an orifice 28.
- Pilot course 24 is also connected to a pilot operation valve V2 through an orifice 29.
- a variable drain pump 1 is connected to a pair of ports 5, 5, each associated respectively with a switching valve 3 or with switching valve 4 through a high pressure fluid course 2.
- Each of a pair of pilot chambers 3a, 3b and 4a, 4b respectively attached at opposite sides of each of switching valves 3 and 4 and coupled to pilot operating valves V1 and V2, whereby pilot operating valves V1 and V2 control an output pilot pressure.
- Switching valves 3 and 4 are normally in a neutral position and ports 5, 5 are closed. Switching valves 3 and 4 are each associated with a pair of variable orifices 6, 6'. Placing either of switching valves 3 or 4 in either a left or a right position opens the pair of variable orifices 6, 6' associated with that valve. The opening of the pair of variable orifices 6, 6' is proportional to the setting of the valve.
- each pair of variable orifices 6, 6' is a pressure compensating valve 8 connected through a check valve 7.
- Each of switching valves 3 and 4 has a supply port 9 that connects to the lower side of pressure compensating valve 8. Supply ports 9, 9 are closed when switching valves 3 and 4 are in a neutral position. Moving switching valves 3, 4 to either a left or a right position couples supply ports 9, 9 with either of a pair of actuator ports 10, 11 and connects the other actuator port with a tank fluid course 12.
- a pair of load detecting ports 13, 13 attached to switching valves 3 and 4 is connected with tank fluid course 12 when switching valves 3 and 4 are in a neutral position.
- each of load detecting ports 13 is connected to the actuator port 10, 11 with the higher pressure.
- Pressure compensating valves 8, 8 equalize the respective pressures of the upper side of check valves 7, 7 to that of pilot chambers 8a, 8a and the respective pressures of load detecting ports 13, 13 to that of pilot chambers 8b, 8b.
- a shuttle valve 14 transfers to pilot chamber 8b the highest pressure of any actuator controlled by switching valves 3 and 4.
- Pressure compensating valve 8 operates at the pressure of the lower of the pair of variable orifices 6, 6', that is, at a fixed-rate higher than the maximum load pressure.
- the maximum load pressure chosen by shuttle valve 14 is transferred to a pilot chamber 15a of a control valve 15, and a pilot chamber 15b has the pressure of high pressure fluid course 2 or the pressure of variable drain pump 1. Accordingly, the difference between the pressure of variable drain pump 1 and the maximum load pressure actuates control valve 15.
- Control valve 15 operates control cylinder 16, which runs at constant power, to keep the pressure from variable drain pump 1 at a fixed rate higher than the maximum load pressure.
- Each pair of actuator ports 10 and 11 of switching valves 3 and 4 is connected respectively to a pair of cylinders 19 and 20 through a pair of fluid courses 17 and 18 to which each of a pair of overload relief valves 21 and 22 are connected.
- pilot operating valves V1 and V2 supply a pilot pressure to either pilot chambers 3a, 3b of switching valve 3 or pilot chambers 4a, 4b of switching valve 4.
- pilot pressure from pilot chamber 3b shifts switching valve 3 to the right position.
- pilot pressure from pilot chamber 4b shifts switching valve 4 to the right position.
- variable drain pump 1 supplies amounts of fluid under pressure that correspond to the ratio of the two pairs of variable orifices.
- the fluid is supplied to bottom chambers 19a and 20a of cylinders 19 and 20 or to individual actuators.
- the fluid in rod chambers 19b, 20b returns to tank fluid course 12 through switching valves 3 and 4.
- Control cylinder 16 controls the quantity of fluid from pump 1 according to the maximum load pressure on any one among the actuators.
- a full stroke of cylinder 20 raises the pressure and opens pilot valve 25. Pilot chamber 4b of switching valve 4 makes a connection with tank T. The pressure is decreased, and switching valve 4 returns to a neutral position, thereby reducing the opening of the pair of variable orifices 6, 6'. As a result, the amount of fluid flowing to cylinder 20 is decreased.
- variable drain pump 1 when the level of the pair of variable orifices 6, 6' of switching valve 4 becomes less than the level of the pair of switching valve 3, the amount of fluid from variable drain pump 1 is decreased in proportion to the ratio of the two levels, so that fluid under pressure is supplied to fluid cylinder 19 connected to switching valve 3.
- pilot valve 25 is connected only to bottom chamber 20a of cylinder 20. Pilot valve 25 may also connect to a single fluid course 17 or to both fluid courses 17 and 18.
- a second embodiment there are switching valves additional to switching valves 3 and 4.
- the load pressure of all switching valves is led to pilot chamber 15a at one side of control valve 15 by three shuttle valves 30, 31, 32.
- a switching valve 34 is located between load detecting port 13 of switching valve 3 and shuttle valve 32.
- a spring 35 normally keeps shuttle valve 32 open; it closes when the pilot pressure to a pilot chamber 34a overcomes the restoring force of spring 35. Pilot chamber 34a is connected with the upper side of shuttle valve 32 through a fluid course 36.
- switching valve 34 keeps opening, so that, whatever the pressure in shuttle valve 32 (either P f from a fluid course 33, P F , or a higher pressure P lmax ), that pressure is fed back to regulate control valve 15.
- the fluid pressure from variable drain pump 1 is controlled by the maximum value of the load pressures in all actuators.
- P F is greater than P SP
- switching valve 34 keeps opening so that P F is fed back to control valve 15 of the regulator. No matter what value the load pressure P f of cylinder 19 takes, the pressure fed back is fixed by P F .
- P F When cylinder 19 reaches the end of its stroke and P f is greater than P F , the former becomes at most P F plus a small constant ⁇ .
- first, second, and third switching valves 40, 41, 42 are respectively connected to a boom cylinder 37, a bucket cylinder 38, and a spin motor 39.
- the structure, including each switching valve and each pressure compensating valve 8, is the same as in the first embodiment.
- a T-connector joins one end of a fluid course 44 to the lower of a pair of variable orifices 6, 6' of third switching valve 42 and to pressure compensating valve 8.
- the other end of fluid course 44 connects to an inlet port 46 of a pilot operating valve 45.
- An outlet port 47 of pilot operating valve 45 connects to the bottom of boom cylinder 37 through a load checking valve 48.
- pilot operating valve 45 When pilot operating valve 45 is in its normal position, it prevents inlet port 46 from coupling to outlet port 47. When a pilot chamber 49 reaches a pilot pressure, both inlet port 46 and outlet port 47 are connected through an orifice 50. Then the pilot pressure in pilot chamber 49 actuates first switching valve 40, thereby controlling boom cylinder 37 by pilot operating valve 45 as follows.
- first switching valve 40 When first switching valve 40 is switched to the left side, as shown in Fig. 6, the pilot pressure from first switching valve 40 goes to pilot chamber 49 and causes pilot operating valve 45 to open. A portion of the fluid pressure supplied to the system of spin motor 39 is also supplied to the bottom of boom cylinder 37 through pilot operating valve 45.
- a T-connector joins a fluid course 44 to the lower side of a pressure compensating valve 8 and to a supply port 9 of a third switching valve 42.
- the other end of fluid course 44 connects to an inlet port 46 of a pilot operating valve 45.
- the fourth embodiment has the same structure as the third.
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- Engineering & Computer Science (AREA)
- General Engineering & Computer Science (AREA)
- Physics & Mathematics (AREA)
- Fluid Mechanics (AREA)
- Mining & Mineral Resources (AREA)
- Civil Engineering (AREA)
- Structural Engineering (AREA)
- Mechanical Engineering (AREA)
- Fluid-Pressure Circuits (AREA)
- Operation Control Of Excavators (AREA)
Priority Applications (3)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
EP95202288A EP0684388B1 (de) | 1991-12-25 | 1992-12-23 | Lastdruckkompensierte hydraulische Steuereinrichtung |
EP95202286A EP0684387B1 (de) | 1991-12-25 | 1992-12-23 | Lastdruckkompensierte hydraulische Steuereinrichtung |
EP95202287A EP0684389B1 (de) | 1991-12-25 | 1992-12-23 | Steuereinrichtung für hydraulisches System mit mehreren Verbrauchern |
Applications Claiming Priority (6)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
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 |
JP212244/92 | 1992-07-16 | ||
JP21224492A JPH0633904A (ja) | 1992-07-16 | 1992-07-16 | 負荷感応形制御装置 |
JP250517/92 | 1992-08-26 | ||
JP04250517A JP3128775B2 (ja) | 1992-08-26 | 1992-08-26 | 負荷感応形制御装置 |
Related Child Applications (6)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
EP95202287.9 Division-Into | 1992-12-23 | ||
EP95202286A Division EP0684387B1 (de) | 1991-12-25 | 1992-12-23 | Lastdruckkompensierte hydraulische Steuereinrichtung |
EP95202286.1 Division-Into | 1992-12-23 | ||
EP95202288A Division EP0684388B1 (de) | 1991-12-25 | 1992-12-23 | Lastdruckkompensierte hydraulische Steuereinrichtung |
EP95202288.7 Division-Into | 1992-12-23 | ||
EP95202287A Division EP0684389B1 (de) | 1991-12-25 | 1992-12-23 | Steuereinrichtung für hydraulisches System mit mehreren Verbrauchern |
Publications (2)
Publication Number | Publication Date |
---|---|
EP0550257A1 true EP0550257A1 (de) | 1993-07-07 |
EP0550257B1 EP0550257B1 (de) | 1998-05-06 |
Family
ID=27329339
Family Applications (4)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
EP95202287A Expired - Lifetime EP0684389B1 (de) | 1991-12-25 | 1992-12-23 | Steuereinrichtung für hydraulisches System mit mehreren Verbrauchern |
EP19920311770 Expired - Lifetime EP0550257B1 (de) | 1991-12-25 | 1992-12-23 | Einrichtung zur Steuerung mehrerer Servomotoren |
EP95202288A Expired - Lifetime EP0684388B1 (de) | 1991-12-25 | 1992-12-23 | Lastdruckkompensierte hydraulische Steuereinrichtung |
EP95202286A Expired - Lifetime EP0684387B1 (de) | 1991-12-25 | 1992-12-23 | Lastdruckkompensierte hydraulische Steuereinrichtung |
Family Applications Before (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
EP95202287A Expired - Lifetime EP0684389B1 (de) | 1991-12-25 | 1992-12-23 | Steuereinrichtung für hydraulisches System mit mehreren Verbrauchern |
Family Applications After (2)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
EP95202288A Expired - Lifetime EP0684388B1 (de) | 1991-12-25 | 1992-12-23 | Lastdruckkompensierte hydraulische Steuereinrichtung |
EP95202286A Expired - Lifetime EP0684387B1 (de) | 1991-12-25 | 1992-12-23 | Lastdruckkompensierte hydraulische Steuereinrichtung |
Country Status (2)
Country | Link |
---|---|
EP (4) | EP0684389B1 (de) |
DE (4) | DE69225392T2 (de) |
Cited By (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
EP0877169A2 (de) * | 1997-05-07 | 1998-11-11 | Robert Bosch Gmbh | Hydraulische Steuereinrichtung zur lastdruckunabhängigen Steuerung eines doppeltwirkenden Motors |
EP1138956A1 (de) * | 2000-03-28 | 2001-10-04 | Mannesmann Rexroth S.A. | Hydraulischer Schaltkreis zur Ansteuerung mehrerer, hydraulischer Verbraucher |
Families Citing this family (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
DE19831595B4 (de) * | 1998-07-14 | 2007-02-01 | Bosch Rexroth Aktiengesellschaft | Hydraulische Schaltung |
WO2012060742A1 (en) * | 2010-11-01 | 2012-05-10 | Volvo Construction Equipment Ab | A method for controlling a hydraulic system of a working machine |
CN104627880B (zh) * | 2014-12-31 | 2017-02-22 | 中联重科股份有限公司 | 闭式***、控制方法、卷扬***和履带式车辆行走*** |
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***及其控制方法 |
Citations (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
DE3710699C1 (de) * | 1987-03-31 | 1988-08-18 | Heilmeier & Weinlein | Hydraulische Steuervorrichtung fuer eine Verbrauchergruppe |
WO1990002882A1 (en) * | 1988-09-09 | 1990-03-22 | Atlas Copco Aktiebolag | Hydraulic driving system with a priority function for hydraulic motors |
EP0433454A1 (de) * | 1989-05-24 | 1991-06-26 | Kabushiki Kaisha Komatsu Seisakusho | Hydraulische schaltungsvorrichtung |
-
1992
- 1992-12-23 DE DE1992625392 patent/DE69225392T2/de not_active Expired - Fee Related
- 1992-12-23 DE DE1992628489 patent/DE69228489T2/de not_active Expired - Fee Related
- 1992-12-23 EP EP95202287A patent/EP0684389B1/de not_active Expired - Lifetime
- 1992-12-23 DE DE1992629968 patent/DE69229968T2/de not_active Expired - Fee Related
- 1992-12-23 EP EP19920311770 patent/EP0550257B1/de not_active Expired - Lifetime
- 1992-12-23 DE DE1992629966 patent/DE69229966T2/de not_active Expired - Fee Related
- 1992-12-23 EP EP95202288A patent/EP0684388B1/de not_active Expired - Lifetime
- 1992-12-23 EP EP95202286A patent/EP0684387B1/de not_active Expired - Lifetime
Patent Citations (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
DE3710699C1 (de) * | 1987-03-31 | 1988-08-18 | Heilmeier & Weinlein | Hydraulische Steuervorrichtung fuer eine Verbrauchergruppe |
WO1990002882A1 (en) * | 1988-09-09 | 1990-03-22 | Atlas Copco Aktiebolag | Hydraulic driving system with a priority function for hydraulic motors |
EP0433454A1 (de) * | 1989-05-24 | 1991-06-26 | Kabushiki Kaisha Komatsu Seisakusho | Hydraulische schaltungsvorrichtung |
Cited By (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
EP0877169A2 (de) * | 1997-05-07 | 1998-11-11 | Robert Bosch Gmbh | Hydraulische Steuereinrichtung zur lastdruckunabhängigen Steuerung eines doppeltwirkenden Motors |
EP0877169A3 (de) * | 1997-05-07 | 2000-01-19 | Robert Bosch Gmbh | Hydraulische Steuereinrichtung zur lastdruckunabhängigen Steuerung eines doppeltwirkenden Motors |
EP1138956A1 (de) * | 2000-03-28 | 2001-10-04 | Mannesmann Rexroth S.A. | Hydraulischer Schaltkreis zur Ansteuerung mehrerer, hydraulischer Verbraucher |
FR2807118A1 (fr) * | 2000-03-28 | 2001-10-05 | Mannesmann Rexroth Sa | Circuit hydraulique pour l'actionnement de recepteurs hydrauliques multiples |
Also Published As
Publication number | Publication date |
---|---|
DE69228489D1 (de) | 1999-04-01 |
EP0550257B1 (de) | 1998-05-06 |
EP0684389A2 (de) | 1995-11-29 |
EP0684387A2 (de) | 1995-11-29 |
EP0684389B1 (de) | 1999-09-08 |
DE69228489T2 (de) | 1999-09-30 |
DE69225392D1 (de) | 1998-06-10 |
DE69229968T2 (de) | 2000-03-09 |
EP0684388A2 (de) | 1995-11-29 |
EP0684387A3 (de) | 1996-10-30 |
EP0684389A3 (de) | 1996-10-30 |
DE69229968D1 (de) | 1999-10-14 |
EP0684388B1 (de) | 1999-02-24 |
EP0684387B1 (de) | 1999-09-08 |
DE69225392T2 (de) | 1998-09-03 |
DE69229966T2 (de) | 2000-03-09 |
DE69229966D1 (de) | 1999-10-14 |
EP0684388A3 (de) | 1996-11-06 |
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