EP3686440B1 - Fluid pressure control device - Google Patents
Fluid pressure control device Download PDFInfo
- Publication number
- EP3686440B1 EP3686440B1 EP19872249.8A EP19872249A EP3686440B1 EP 3686440 B1 EP3686440 B1 EP 3686440B1 EP 19872249 A EP19872249 A EP 19872249A EP 3686440 B1 EP3686440 B1 EP 3686440B1
- Authority
- EP
- European Patent Office
- Prior art keywords
- passage
- circuit system
- pump
- neutral
- valve
- 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.)
- Active
Links
- 239000012530 fluid Substances 0.000 title claims description 65
- 230000007935 neutral effect Effects 0.000 claims description 159
- 238000011144 upstream manufacturing Methods 0.000 claims description 15
- 239000003921 oil Substances 0.000 description 100
- 238000007599 discharging Methods 0.000 description 12
- 230000004048 modification Effects 0.000 description 5
- 238000012986 modification Methods 0.000 description 5
- 238000009434 installation Methods 0.000 description 4
- 238000010276 construction Methods 0.000 description 3
- 230000000694 effects Effects 0.000 description 3
- 238000010586 diagram Methods 0.000 description 2
- 239000010720 hydraulic oil Substances 0.000 description 2
- 238000003780 insertion Methods 0.000 description 1
- 230000037431 insertion Effects 0.000 description 1
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 1
Images
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
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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
- E02F9/2239—Control of flow rate; Load sensing arrangements using two or more pumps with cross-assistance
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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
- E02F9/2264—Arrangements or adaptations of elements for hydraulic drives
- E02F9/2267—Valves or distributors
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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
- E02F9/2264—Arrangements or adaptations of elements for hydraulic drives
- E02F9/2271—Actuators and supports therefor and protection therefor
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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
- E02F9/2282—Systems using center bypass type changeover 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
- E02F9/2292—Systems with two or more pumps
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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
- F15B11/17—Servomotor systems without provision for follow-up action; Circuits therefor with two or more servomotors using two or more pumps
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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
- F15B13/00—Details of servomotor systems ; Valves for servomotor systems
- F15B13/02—Fluid distribution or supply devices characterised by their adaptation to the control of servomotors
- F15B13/06—Fluid distribution or supply devices characterised by their adaptation to the control of servomotors for use with two or more servomotors
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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
- F15B13/00—Details of servomotor systems ; Valves for servomotor systems
- F15B13/02—Fluid distribution or supply devices characterised by their adaptation to the control of servomotors
- F15B13/06—Fluid distribution or supply devices characterised by their adaptation to the control of servomotors for use with two or more servomotors
- F15B13/08—Assemblies of units, each for the control of a single servomotor only
- F15B13/0803—Modular units
- F15B13/0832—Modular valves
- F15B13/0839—Stacked plate type 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
- F15B2211/20—Fluid pressure source, e.g. accumulator or variable axial piston pump
- F15B2211/205—Systems with pumps
- F15B2211/20507—Type of prime mover
- F15B2211/20523—Internal combustion engine
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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
- F15B2211/20538—Type of pump constant capacity
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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
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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
- F15B2211/20576—Systems with pumps with multiple pumps
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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
- F15B2211/3056—Assemblies of multiple valves
- F15B2211/3059—Assemblies of multiple valves having multiple valves for multiple output members
- F15B2211/30595—Assemblies of multiple valves having multiple valves for multiple output members with additional valves between the groups of valves for multiple output members
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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
- F15B2211/31—Directional control characterised by the positions of the valve element
- F15B2211/3105—Neutral or centre positions
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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
- F15B2211/31—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
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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
- F15B2211/31—Directional control characterised by the positions of the valve element
- F15B2211/3105—Neutral or centre positions
- F15B2211/3116—Neutral or centre positions the pump port being open in the centre position, e.g. so-called open centre
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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
- F15B2211/315—Directional control characterised by the connections of the valve or valves in the circuit
- F15B2211/31523—Directional control characterised by the connections of the valve or valves in the circuit being connected to a pressure source and an output member
- F15B2211/31535—Directional control characterised by the connections of the valve or valves in the circuit being connected to a pressure source and an output member having multiple pressure sources and a single output member
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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
- F15B2211/315—Directional control characterised by the connections of the valve or valves in the circuit
- F15B2211/3157—Directional control characterised by the connections of the valve or valves in the circuit being connected to a pressure source, an output member and a return line
- F15B2211/31582—Directional control characterised by the connections of the valve or valves in the circuit being connected to a pressure source, an output member and a return line having multiple pressure sources and a single output member
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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
- F15B2211/42—Flow control characterised by the type of actuation
- F15B2211/428—Flow 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
- F15B2211/45—Control of bleed-off flow, e.g. control of bypass flow to the return line
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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
- F15B2211/70—Output members, e.g. hydraulic motors or cylinders or control therefor
- F15B2211/71—Multiple output members, e.g. multiple hydraulic motors or cylinders
- F15B2211/7135—Combinations of output members of different types, e.g. single-acting cylinders with rotary motors
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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
- F15B2211/7142—Multiple output members, e.g. multiple hydraulic motors or cylinders the output members being arranged in multiple groups
Definitions
- the present invention relates to a fluid pressure control device.
- JP2016-204826A discloses a fluid pressure control device including: a first circuit system with a plurality of control valves connected to a first pump; and a second circuit system with a plurality of control valves connected to a second pump.
- the fluid pressure control device according to JP2016-204826A is provided with a neutral cut valve adapted to make a first neutral passage and a tank communicate with each other or block the communication therebetween, and an external output passage that is in communication with an upstream side of the neutral cut valve and through which a working fluid discharged from the first pump can be supplied to the outside.
- the working fluid can be drawn out from the first circuit system to the outside through the external output passage.
- the working fluid can be drawn out to a circuit system different from the first circuit system through the external output passage.
- the first circuit system is provided with only one external output passage.
- the fluid pressure control device has a problem that a circuit system other than the circuit system connected to the external output passage cannot be additionally connected to the first circuit system, meaning that a degree of freedom in terms of circuit system expansion is low.
- JP H09 235759 A discloses a control circuit with a main fluid hydraulic circuit with a first hydraulic pump operating actuators for driving an attachment and a movable actuation part, a second hydraulic pump operating an actuator for driving a construction machine, control valves and a control valve for the construction machine, hydraulic circuits of a pilot fluid for the construction machine, and an auxiliary fluid hydraulic circuit supplying the hydraulic oil from the second hydraulic pump to the actuators.
- An object of the present invention is to provide a fluid pressure control device with a high degree of freedom in terms of circuit system expansion.
- a fluid pressure control device 100 according to a first embodiment of the present invention will be described with reference to FIG. 1 and FIG. 2 .
- the fluid pressure control device 100 is used for a working machine such as a power excavator.
- a working machine such as a power excavator
- the fluid pressure control device 100 can be applied to other working machines such as a wheel loader.
- working oil is used as a working fluid.
- other types of fluid such as working water may be used as the working fluid.
- the power excavator includes a traveling unit of a crawler type, a swiveling unit that is provided on an upper part of the traveling unit to be able to swivel, and an excavating unit that is provided to the swiveling unit.
- the traveling unit includes a pair of left and right crawlers.
- the power excavator travels with the pair of left and right crawlers driven.
- the excavating unit includes a boom that is pivotally attached to the swiveling unit, an arm that is pivotally attached to the boom, and a bucket that is pivotally attached to the arm.
- the power excavator includes an engine (not illustrated), a first pump 10 and a second pump 20 serving as hydraulic pressure pumps that is driven by the engine to discharge the working oil, a fluid pressure control device 100 that controls actuators for driving the traveling unit, the swiveling unit, and the excavating unit by using the working oil discharged from the first pump 10 and the second pump 20, and a tank T to which the working oil returns from the fluid pressure control device 100.
- the fluid pressure control device 100 controls a plurality of actuators that are driven by the working oil discharged from the first pump 10 and the second pump 20.
- the plurality of actuators include traveling unit driving hydraulic motors 7A and 8A, a swiveling unit driving hydraulic motor (not illustrated), an arm driving hydraulic cylinder (not illustrated), a bucket driving hydraulic cylinder 7B, an auxiliary attachment driving hydraulic cylinder 8B, an additional attachment driving hydraulic cylinder 9A, and the like.
- auxiliary attachment and the additional attachment examples include a breaker and crusher attached instead of the bucket, an offset device that causes a sliding movement of the boom in a left and right direction, a dozer blade attached to the swiveling unit, and the like.
- the fluid pressure control device 100 includes: a first circuit system HC1 that is connected to the first pump 10 and receives working oil supplied from the first pump 10; a second circuit system HC2 that is connected to the second pump 20 and receives working oil supplied from the second pump 20; and a third circuit system HC3 that is connected to the first circuit system HC1 and receives working oil supplied from the first pump 10 via a neutral cut valve 110 described later.
- a straight traveling control valve 6 is switched so that the working oil discharged from the first pump 10 is also supplied to the second circuit system HC2 and the working oil discharged from the second pump 20 is also supplied to the first circuit system HC1 and the third circuit system HC3.
- the fluid pressure control device 100 includes: a main valve block 101 including the first circuit system HC1 and the second circuit system HC2 serving as a main circuit system; and a sub valve block 103 including the third circuit system HC3 serving as a sub circuit system.
- the sub valve block 103 can be attached to the main valve block 101 by using a plurality of bolts 105.
- the main valve block 101 may be formed by stacking and fastening a plurality of valve blocks, or may be formed by a single valve block.
- the main valve block 101 has bolt attachment holes 115, for attaching the bolts 105, opening in the outer surface.
- the sub valve block 103 is fixed to the main valve block 101 with the sub valve block 103 placed on the main valve block 101, shaft portions of the bolts 105 inserted through bolt insertion holes 135 of the sub valve block 103, and tip portions of the shaft portions of the bolts 105 screwed to the bolt attachment holes 115.
- the sub valve block 103 is provided adapted to control the hydraulic cylinder 9A for driving the additional attachment.
- the third circuit system HC3 has been required to be connected to a new hydraulic pump different from the first pump 10 or the second pump 20, with the sub valve block 103 provided to be separate from the main valve block 101.
- the sub valve block 103 can be attached on the main valve block 101, whereby an installation area of the fluid pressure control device 100 can be reduced. Furthermore, no pipe needs to be provided between the main valve block 101 and the sub valve block 103, whereby an installation space of the fluid pressure control device 100 can be made small. Furthermore, as will be described later, no new hydraulic pump needs to be connected to the sub valve block 103 because the working oil from the first pump 10 is supplied to the sub valve block 103 through the main valve block 101. All things considered, according to the present embodiment, the number of parts and cost can be reduced compared with a case where the sub valve block 103 connected with the new hydraulic pump is provided to be separate from the main valve block 101.
- the first circuit system HC1 includes: a first neutral passage 11 serving as a main neutral passage that guides the working oil discharged from the first pump 10 to the tank T; first control valves 12 serving as a plurality of main control valves connected in series with the first neutral passage 11; a first parallel passage 13 that is branched off from the first neutral passage 11 more on the upstream side than the straight traveling control valve 6 described later; and a discharge passage 19 connected to the tank T.
- the plurality of first control valves 12 are connected in series through the first neutral passage 11, and are connected in parallel through the first parallel passage 13.
- the first control valves 12, which are main control valves adapted to control the actuator provided to the first circuit system HC1, include a first traveling control valve 12A, a bucket control valve 12B, a boom first speed control valve 12C, and an arm second speed control valve 12D.
- the working oil discharged from the first pump 10 is guided to the first traveling control valve 12A, the bucket control valve 12B, the boom first speed control valve 12C, and the arm second speed control valve 12D in this order from the upstream side.
- the first traveling control valve 12A is adapted to control supplying/discharging of the working oil to/from the traveling unit driving hydraulic motor 7A, provided on the left side of the vehicle body of the power excavator.
- the bucket control valve 12B is adapted to control supplying/discharging of the working oil to/from the bucket driving hydraulic cylinder 7B.
- the boom first speed control valve 12C is adapted to control supplying/discharging of the working oil to/from a boom driving hydraulic cylinder (not illustrated).
- the arm second speed control valve 12D is adapted to control supplying/discharging of the working oil to/from an arm driving hydraulic cylinder (not illustrated).
- the main actuators (such as the hydraulic motor 7A and the hydraulic cylinder 7B) controlled using the first control valves 12 are also collectively referred to as a first actuator 7.
- the first circuit system HC1 includes the plurality of first control valve 12 that are connected to the first pump 10, and are used adapted to control the plurality of first actuators 7.
- the discharge passage 19 guides the working oil discharged from the first actuator 7 via the first control valve 12 to the tank T.
- the working oil discharged from the first pump 10 returns to the tank T through the first neutral passage 11, when the straight traveling control valve 6 described later is at a normal position (A), the neutral cut valve 110 described later is at a first position (P1), and all the first control valves 12 are at neutral positions.
- the communication between the first pump 10 in the first neutral passage 11 and the tank T is blocked.
- the working oil discharged from the first pump 10 can be supplied to the first control valves 12B to 12D through the first parallel passage 13, even when the communication between the first pump 10 in the first neutral passage 11 and the tank T is blocked due to any one of the first control valves 12A to 12C being switched to the drive position.
- the first circuit system HC1 further includes: the neutral cut valve 110 that is provided on the downstream side (the downstream side of the arm second speed control valve 12D) of all the first control valves 12 in the first neutral passage 11, and adapted to make the first neutral passage 11 and the tank T communicate with each other or block the communication therebetween; a first external output passage 14; a first external output passage 14 through which the working oil discharged from the first pump 10 can be supplied to the outside, the first external output passage 14 being in communication with the downstream side of all the first control valves 12 in the first neutral passage 11 (thus, the downstream side of the arm second speed control valve 12D) and the upstream side of the neutral cut valve 110; and a second external output passage 15 through which the working oil discharge from the first pump 10 and guided via the neutral cut value 110 can be supplied to the outside.
- the neutral cut valve 110 that is provided on the downstream side (the downstream side of the arm second speed control valve 12D) of all the first control valves 12 in the first neutral passage 11, and adapted to make the first neutral passage 11 and the tank
- the first external output passage 14 is connected to a first external output port 14o opening in the outer surface of the main valve block 101.
- the second external output passage 15 is connected to a second external output port 15o opening in the outer surface of the main valve block 101.
- the first parallel passage 13 is connected to an output port 13o opening in the outer surface of the main valve block 101.
- the first circuit system HC1 further includes branch passages 191 and 192 branched off from the discharge passage 19 guiding the working oil to the tank T.
- the branch passages 191 and 192 are respectively connected to introduction ports 191i and 192i opening in the outer surface of the main valve block 101.
- the neutral cut valve 110 is a pilot switching valve with a spool switched among the first position (P1), the second position (P2), and the third position (P3) in accordance with pilot pressure supplied to a first pilot pressure chamber 116a and a second pilot pressure chamber 116b.
- the pilot pressure applied to the first pilot pressure chamber 116a and the second pilot pressure chamber 116b is controlled on the basis of an operation state of the power excavator, an operation position of a dedicated operation member (not illustrated) for operating the neutral cut valve 110, and the like.
- the neutral cut valve 110 is maintained at the first position (P1) by biasing force from a centering spring 117, when no pilot pressure is applied to each of the first pilot pressure chamber 116a and the second pilot pressure chamber 116b.
- the neutral cut valve 110 includes: a first inlet port 111 and a second inlet port 112 that are in communication with the downstream side of the arm second speed control valve 12D in the first neutral passage 11; a tank port 119 that is in communication with the discharge passage 19; and an outlet port 113 that is in communication with the second external output passage 15.
- the neutral cut valve 110 When the neutral cut valve 110 is at the first position (P1), the first inlet port 111 and the tank port 119 communicate with each other, and the communication between the second inlet port 112 and the outlet port 113 is blocked. When the first inlet port 111 and the tank port 119 communicate with each other, the working oil guided to the first neutral passage 11 is guided to the discharge passage 19 via the neutral cut valve 110.
- the neutral cut valve 110 at the first position (P1) disables the supplying of the working oil, discharged from the first pump 10, to the outside of the main valve block 101 through the second external output passage 15, and enables the working oil, discharged from the first pump 10, to be guided to the tank T through the discharge passage 19.
- the neutral cut valve 110 at the second position (P2) disables the supplying of the working oil, discharged from the first pump 10, to the outside of the main valve block 101 through the second external output passage 15, and disables the working oil, discharged from the first pump 10, to be guided to the tank T through the discharge passage 19.
- the neutral cut valve 110 When the neutral cut valve 110 is at the third position (P3), the communication between the first inlet port 111 and tank port 119 is blocked, and the second inlet port 112 and the outlet port 113 communicate with each other. When the second inlet port 112 and the outlet port 113 communicate with each other, the working oil guided to the first neutral passage 11 is guided to the second external output passage 15 via the neutral cut valve 110.
- the neutral cut valve 110 at the third position (P3) enables the working oil, discharged from the first pump 10, to be supplied to the outside of the main valve block 101 through the second external output passage 15, and disables the guiding of the working oil, discharged from the first pump 10, to the tank T through the discharge passage 19.
- the first position (P1) is a position with which the first neutral passage 11 and the tank T communicate with each other
- the second position (P2) and the third position (P3) are position with which the communication between the first neutral passage 11 and the tank T is blocked.
- the third position (P3) is a position with which the first neutral passage 11 and a third neutral passage 31 of the third circuit system HC3 described later communicate with each other
- the first position (P1) and the second position (P2) are positions at which the communication between the first neutral passage 11 and the third neutral passage 31 is blocked.
- the sub valve block 103 is adapted to be attached to the main valve block 101 so that the working oil discharged from the first pump 10 can be further supplied to the third circuit system HC3 through the first circuit system HC1.
- the ports (13o, 15o, 191i, and 192i) opening in the outer surface of the main valve block 101 are closed by plugs.
- the ports (13o, 15o, 191i, and 192i) opening in the outer surface of the main valve block 101 are connected to the ports (33i, 31i, 38o, and 39o) opening in the outer surface of the sub valve block 103.
- the third circuit system HC3 includes: a third neutral passage 31 that guides the working oil, guided via the neutral cut valve 110 and through the second external output passage 15 in the first circuit system HC1, to the tank T; a third control valve 32 serving as a sub control valve that is connected to the third neutral passage 31 and is adapted to control the third actuator 9 serving as the sub actuator; a third parallel passage 33 that guides the working oil, guided through the first parallel passage 13 in the first circuit system HC1, to the third control valve 32; and discharge passages 38 and 39 that are in communication with the discharge passage 19 in the first circuit system HC1.
- the third neutral passage 31 is connected to the second external output passage 15 in the first circuit system HC1, and functions as a second external input passage to which the working oil is guided through the first circuit system HC1.
- the first neutral passage 11, the second external output passage 15, and the third neutral passage 31 function as a neutral passage through which the working oil discharged from the first pump 10 returns to the tank T.
- the plurality of first and the third control valves 12 and 32 are connected in series through the first neutral passage 11, the second external output passage 15, and the third neutral passage 31 serving as the neutral passage, and are connected in parallel through the first parallel passage 13 and the third parallel passage 33.
- the third control valve 32 is adapted to control supplying/discharging of the working oil to/from the hydraulic cylinder 9A serving as the third actuator 9 driving the additional attachment in accordance with the pilot pressure applied to the pilot pressure chamber.
- the third circuit system HC3 includes the third control valve 32 adapted to control the third actuator 9, using the working oil discharged from the first pump 10 and supplied through the main valve block 101.
- the third control valve 32 is an open center type control valve adapted to make the third neutral passage 31 and the discharge passage 39 communicate with each other while being at the neutral position, for guiding the working oil, guided to the third neutral passage 31, to the tank T.
- the third neutral passage 31 is connected to the external input port 31i opening in the outer surface of the sub valve block 103.
- the external input port 31i of the sub valve block 103 is connected to the second external output port 15o of the main valve block 101.
- the third parallel passage 33 is connected to the input port 33i opening in the outer surface of the sub valve block 103.
- the input port 33i of the sub valve block 103 is connected to the output port 13o of the main valve block 101.
- the discharge passage 38 to which the working oil is guided from the hydraulic cylinder 9A via the third control valve 32 is connected to a draw out port 38o opening in the outer surface of the sub valve block 103.
- the draw out port 38o of the sub valve block 103 is connected to the introduction port 191i of the main valve block 101.
- the discharge passage 39 to which the working oil is guided from the third neutral passage 31 via the third control valve 32 is connected to a draw out port 39o opening in the outer surface of the sub valve block 103.
- the draw out port 39o of the sub valve block 103 is connected to the introduction port 192i of the main valve block 101.
- the second circuit system HC2 includes: a second neutral passage 21 serving as a main neutral passage through which the working oil discharged from the second pump 20 is guided to the tank T; second control valves 22 serving as plurality of main control valves connected in series with the second neutral passage 21; a second parallel passage 23 branched off from the second neutral passage 21 more on the upstream side than the second control valve 22; and a discharge passage 19 connected to the tank T.
- the plurality of second control valves 22 are connected in series through the second neutral passage 21, and are connected in parallel through the second parallel passage 23.
- the second control valves 22 that are main control valves adapted to control actuators provided in the second circuit system HC2 include: a second traveling control valve 22A, an auxiliary corresponding control valve 22B, a swiveling control valve 22C, a boom second speed control valve 22D, and an arm first speed control valve 22E.
- the working oil discharged from the second pump 20 is guided to the second traveling control valve 22A, the auxiliary corresponding control valve 22B, the swiveling control valve 22C, the boom second speed control valve 22D, and the arm first speed control valve 22E in this order from the upstream side.
- the second traveling control valve 22A is adapted to control supplying/discharging of the working oil to/from the traveling unit driving hydraulic motor 8A provided on the right side of the vehicle body of the power excavator.
- the auxiliary corresponding control valve 22B is adapted to control supplying/discharging of the working oil to/from the auxiliary attachment driving hydraulic cylinder 8B.
- the swiveling control valve 22C is adapted to control supplying/discharging of the working oil to/from a swiveling unit driving hydraulic motor (not illustrated).
- the boom second speed control valve 22D is adapted to control supplying/ discharging of working oil to and from a boom driving hydraulic cylinder (not illustrated).
- the arm first speed control valve 22E is adapted to control supplying/discharging of the working oil to/from an arm driving hydraulic cylinder (not illustrated).
- the main actuators (such as the hydraulic motor 8A and the hydraulic cylinder 8B) controlled by using the second control valves 22 will be also collectively referred to as a second actuator 8.
- the second circuit system HC2 includes the plurality of second control valves 22 that is connected to the second pump 20 and is adapted to control the plurality of second actuators 8.
- the working oil discharged from the second actuator 8 via the second control valve 22 is guided to the tank T through the discharge passage 19.
- the discharge passage 19 is used as a common passage through which the working oil in the first circuit system HC1 and second circuit system HC2 is guided to the tank T.
- the working oil discharged from the second pump 20 returns to the tank T through the second neutral passage 21 when all the second control valves 22 are at the neutral positions.
- the communication between the second pump 20 in the second neutral passage 21 and the tank T is blocked.
- the working oil discharged from the second pump 20 can be supplied to the second control valve 22B to 22E through the second parallel passage 23, even when the communication between the second pump 20 in the second neutral passage 21 and the tank T is blocked due to any one of the second control valve 22A to 22D being switched to the drive position.
- the second circuit system HC2 includes a first external input passage 24 through which the working oil, supplied from the outside, is guided to the upstream side of a predetermined second control valve 22 (the auxiliary corresponding control valve 22B in the present embodiment).
- the first external input passage 24 is connected to the first external input port 24i opening in the outer surface of the main valve block 101.
- the first circuit system HC1 further includes the straight traveling control valve 6 connected to a point that is more on the downstream side than the point where the first parallel passage 13 is branched off from the first neutral passage 11 and more on the upstream side than the first traveling control valve 12A.
- the straight traveling control valve 6 is connected with a second parallel passage 23.
- the second parallel passage 23 includes a second parallel upstream side passage 23a that connects the second pump 20 and the straight traveling control valve 6 with each other, and a second parallel downstream side passage 23b that connects the straight traveling control valve 6 and the second control valves 22B to 22E to each other.
- the straight traveling control valve 6 is switched between two positions that are a normal position (A) illustrated on the right side in FIG. 1 and a straight traveling position (B) illustrated on the left side in FIG. 1 .
- the straight traveling control valve 6 is switched to the straight traveling position B when the working oil is supplied to the pilot pressure chamber 6a.
- the straight traveling control valve 6 is held at the normal position A by the biasing force from a return spring 6c, when no pilot pressure is applied to the pilot pressure chamber 6a.
- the second parallel upstream side passage 23a of the second parallel passage 23 is connected to the second parallel downstream side passage 23b of the second parallel passage 23, and the first neutral passage 11 more on the downstream side than the straight traveling control valve 6 is connected to the first pump 10.
- the working oil discharged from the first pump 10 is guided to the first control valves 12 through the first neutral passage 11 and the first parallel passage 13.
- the working oil discharged from the second pump 20 is guided to the second control valves 22 through the second neutral passage 21 and the second parallel passage 23.
- the working oil discharged from the first pump 10 is also guided to the third control valve 32 through the first neutral passage 11, via the neutral cut valve 110, and through the second external output passage 15 and the third neutral passage 31.
- the working oil discharged from the first pump 10 is also guided to the third control valve 32 through the first parallel passage 13 and the third parallel passage 33.
- the second parallel upstream side passage 23a of the second parallel passage 23 is connected to the first neutral passage 11 more on the downstream side than the straight traveling control valve 6, and the second parallel downstream side passage 23b is connected to the first pump 10.
- the working oil discharged from the first pump 10 is guided to the first control valves 12B to 12D through the first parallel passage 13, and is guided to the second control valves 22B to 22E through the second parallel downstream side passage 23b of the second parallel passage 23.
- the working oil discharged from the second pump 20 is guided to the first control valve 12A through the first neutral passage 11 more on the downstream side than the straight traveling control valve 6, and is guided to the second control valve 22A through the second neutral passage 21.
- the neutral cut valve 110 In a state where the neutral cut valve 110 is at the third position (P3), the working oil discharged from the first pump 10 is also guided to the third control valve 32 through the first parallel passage 13 and the third parallel passage 33.
- the working oil discharged from the second pump 20 is also guided to the third control valve 32 through the first neutral passage 11, via the neutral cut valve 110, and through the second external output passage 15 and the third neutral passage 31.
- the pilot pressure chamber 6a is at tank pressure, and the straight traveling control valve 6 is maintained at the normal position (A).
- the traveling unit driving hydraulic motors 7A and 8A are operated, the working oil discharged from the first pump 10 is supplied to the first traveling control valve 12A and the working oil discharged from the second pump 20 is supplied to the second traveling control valve 22A.
- the excavating unit actuator is driven while the traveling unit driving hydraulic motors 7A and 8A are driven, the pilot pressure is applied to the pilot pressure chamber 6a, so that the straight traveling control valve 6 is switched to the straight traveling position (B).
- the traveling unit driving hydraulic motors 7A and 8A and an actuator other than the hydraulic motors 7A and 8A are concurrently operated, the working oil discharged from the second pump 20 is supplied to the first traveling control valve 12A and the second traveling control valve 22A.
- the working oil discharged from the first pump 10 is supplied to the other first control valves 12B to 12D, the other second control valves 22B to 22E, and the third control valve 32.
- the circuit for traveling and the circuit for a purpose other than traveling are independent from each other, whereby the vehicle body can reliably travel straight.
- the neutral cut valve 110 has the spool positioned at the first position (P1), in a state where the first pilot pressure chamber 116a and the second pilot pressure chamber 116b are each connected to the tank T and no working oil is supplied into the first pilot pressure chamber 116a or the second pilot pressure chamber 116b. In this state, the first inlet port 111 and the tank port 119 communicate with each other, and the communication between the second inlet port 112 and the outlet port 113 is blocked.
- the working oil that has flowed to the first inlet port 111 through the first neutral passage 11 is discharged to the tank T through the tank port 119.
- the first external output port 14o is constantly in communication with the first neutral passage 11 regardless of the position of the neutral cut valve 110. However, in a state where the neutral cut valve 110 is at the first position (P1), the first neutral passage 11 and the tank T are in communication with each other as described above, whereby the first external output port 14o is also in communication with the tank T. Thus, the working oil discharged from the first pump 10 returns to the tank T without being supplied to the outside through the first external output port 14o.
- the working oil supplied from the first pump 10 to the first circuit system HC1 can be supplied to the outside through the first external output port 14o, by switching the neutral cut valve 110 to the second position (P2).
- the working oil supplied from the first pump 10 to the first circuit system HC1 can be adapted to drive a newly added actuator (not illustrated) or can join the circuit for driving any of the first actuator 7, the second actuator 8, and the third actuator 9, through the first external output port 14o.
- the first external output port 14o and the first external input port 24i are connected to each other through an external pipe 30, outside the main valve block 101. Specifically, the first external output passage 14 is connected to the first external input passage 24 through the external pipe 30.
- the working oil is supplied to the pilot pressure chamber of the auxiliary corresponding control valve 22B adapted to control supplying/discharging of the working oil to/from the hydraulic cylinder 8B, and to the first pilot pressure chamber 116a of the neutral cut valve 110.
- the auxiliary corresponding control valve 22B when the auxiliary corresponding control valve 22B is operated, the working oil discharged from the first pump 10 is supplied to the auxiliary corresponding control valve 22B through the first external output passage 14, the external pipe 30, and the first external input passage 24, in addition to the working oil discharged from the second pump 20.
- the working oil discharged from the first pump 10 is guided to the outside through the first external output passage 14 of the first circuit system HC1, and is guided to the upstream side of the auxiliary corresponding control valve 22B through the first external input passage 24 of the second circuit system HC2 to join the working oil discharged from the second pump 20.
- the neutral cut valve 110 may be adapted to make the first neutral passage 11 and the tank T communicate with each other or block the communication therebetween in accordance with pilot pressure Pp adapted to control the auxiliary corresponding control valve 22B.
- the spring load of the centering spring 117 may be set so that the spool of the neutral cut valve 110 is maintained at the first position (P1) in a state where the pilot pressure Pp is low, and the spool of the neutral cut valve 110 is switched to the second position (P2) in a state where the pilot pressure Pp is high.
- the hydraulic cylinder 8B is driven by the working oil discharged from the second pump 20 only, when the operation amount of the auxiliary corresponding control valve 22B is small.
- the hydraulic cylinder 8B is driven by the working oil discharged from the first pump 10 in addition to the working oil discharged from the second pump 20, when the operation amount of the auxiliary corresponding control valve 22B is large.
- the flow rate of the working oil for the auxiliary corresponding control valve 22B can be increased, whereby the speed of the operation of the hydraulic cylinder 8B controlled by the auxiliary corresponding control valve 22B can be increased.
- the neutral cut valve 110 may be switched to the second position (P2) when the additional actuator is driven.
- the third neutral passage 31 of the third circuit system HC3 is in communication with the first neutral passage 11 of the first circuit system HC1.
- the third parallel passage 33 of the third circuit system HC3 is constantly in communication with the first parallel passage 13 of the first circuit system HC1.
- the plurality of first and third control valves 12 and 32 are connected in series through the first neutral passage 11, the second external output passage 15, and third neutral passage 31 serving as the neutral passage, and is connected in parallel through the first parallel passage 13 and the third parallel passage 33.
- the working oil discharged from the first pump 10 can be supplied to the third control valve 32 through the first parallel passage 13 and the third parallel passage 33, even when the communication between the first pump 10 in the first neutral passage 11 and the tank T is blocked with any of or all of the first control valves 12A to 12D being switched to the drive position.
- the third actuator 9 that can be driven, similarly to the first actuator 7, using the working oil discharged from the first pump 10 or the second pump 20 can be easily added.
- the neutral cut valve 110 By switching the neutral cut valve 110 to the second position (P2), the working oil discharged from the first pump 10 can be supplied to the outside of the main valve block 101 through the first external output passage 14. By switching the neutral cut valve 110 to the third position (P3), the working oil discharged from the first pump 10 can be supplied to the outside of the main valve block 101 through the second external output passage 15.
- the working oil supplied to the first circuit system HC1 from the first pump 10 can be supplied not only to the first external output passage 14, but can also be supplied to the outside through the second external output passage 15, whereby the fluid pressure control device 100 with a high degree of freedom in terms of circuit system expansion can be provided.
- a fluid pressure control device 200 according to a second embodiment of the present invention will be described with reference to FIG. 3 .
- the points different from the first embodiment will be mainly described below, and the configuration that is the same as or corresponding to the configurations described in the first embodiment will be denoted with the same reference numerals and the description thereof will be omitted.
- the third circuit system HC3 includes the third control valve 32 of an open center type.
- the third circuit system HC32 includes a third control valve 232 of a closed center type.
- the configurations of the first circuit system HC1 and the second circuit system HC2 are similar to those in the first embodiment, but the configuration of the third circuit system HC32 is different from that in the first embodiment.
- the second embodiment is similar to the first embodiment in the configuration of the main valve block 101, but is different from the first embodiment in the configuration of the sub valve block 203.
- the sub valve block 203 including the third circuit system HC32 includes an inlet block B30 through which the working oil from the first circuit system HC1 is taken in, and valve blocks B31 and B32 adapted to control the additional attachment driving third actuator 9.
- the inlet block B30 also serves as an outlet block for discharging the working oil to the tank T.
- the valve block B31 has a configuration similar to that of the valve block B32. Thus, the valve block B32 is partially omitted in the drawing.
- the number of valve blocks can be changed as appropriate in accordance with the number of actuators to be added.
- the third circuit system HC32 includes: a plurality of third control valves 232 adapted to control a plurality of third actuators 9; a supply passage 231 serving as a second external input passage connected to the second external output passage 15 of the first circuit system HC1; a tank passage 239 connected to the tank T; and a load pressure passage 241 to which the highest load pressure among those of the plurality of third actuators 9 is guided.
- the supply passage 231 is for guiding the working oil that has been discharged from the first pump 210 and supplied thereto through the first neutral passage 11, the neutral cut valve 110, and the second external output passage 15 to the third control valve 232.
- the third control valve 232 is adapted to control the third actuator 9 by the working oil discharged from the first pump 210 and supplied to the supply passage 231 through the main valve block 101.
- the inlet block B30 is provided with a discharge pressure output port 231p connected to the supply passage 231 and a load pressure output port 241p connected to the load pressure passage 241.
- the inlet block B30 is provided with a relief valve 261 connected to the supply passage 231.
- the relief valve 261 defines the maximum pressure of the circuit formed by connecting the third circuit system HC3 of the sub valve block 203 to the first circuit system HC1 of the main valve block 101.
- the valve blocks B31 and B32 each include a third control valve 232 connected to the supply passage 231, and a pressure compensation valve 234 provided between the third control valve 232 and the third actuator 9.
- the present embodiment employs a load sensing system of an after orifice type, with the pressure compensation valve 234 provided on the downstream side of a meter in throttle portion of the third control valves 232.
- the pressure compensation valve 234 functions to adjust loads among the third actuators 9.
- the pressure compensation valve 234 is provided with pressure on the downstream side of the meter in throttle portion provided to the third control valve 232 and the highest load pressure among those of the plurality of third actuators 9.
- the pressure compensation valve 234 is for compensation with which the pressure on the downstream side of the meter in throttle portion becomes higher than the highest load pressure of the third actuators 9 by a predetermined amount.
- the first pump 210 and the second pump 220 are variable capacity piston pumps, with the discharge capacity varying in accordance with a change in the inclination of a swash plate made by a regulator (not illustrated).
- the discharge capacity of the first pump 210 and the second pump 220 are controlled by what is known as load sensing control, so that a predetermined value is obtained as a difference between the pump discharge pressure guided to the regulator (not illustrated) and the maximum load pressure of the third actuators 9.
- the maximum load pressure of the third actuators 9 is guided to the regulator (not illustrated) of the first pump 210 and second pump 220 from the load pressure output port 241p through a pipe and the like.
- the pump discharge pressure is guided to the regulator (not illustrated) of the first pump 210 and second pump 220 from the discharge pressure output port 231p through a pipe and the like.
- the output port 13o and the introduction ports 191i and 192i not used in the main valve block 101 are closed by the sub valve block 203.
- a closing member such as a plug needs not to be additionally provided, whereby the number of parts can be reduced.
- Such a second embodiment can be provided an advantageous effect that is similar to that of the first embodiment.
- the main valve block 101 according to the second embodiment is similar to that in the first embodiment.
- the main valve block 101 is compatible with any of open center type (see FIG. 1 ) and of closed center type (see FIG. 3 ) third control valves 32 and 232 in the sub valve blocks 103 and 203.
- the neutral cut valve 110 as well as the predetermined ports (15o, 13o, 191i, and 192i) provided, the main valve block 101 featuring high versatility can be provided.
- the first actuator 7 and the first control valve 12 are each provided in a plurality. However, the present invention is not limited to this. It suffices if at least one first actuator 7 and at least one first control valve 12 are provided.
- the second actuator 8 and the second control valve 22 are each provided in a plurality. However, the present invention is not limited to this. It suffices if at least one second actuator 8 and at least one second control valve 22 are provided.
- the first neutral passage 11 of the first circuit system HC1 is provided with the neutral cut valve 110.
- the present invention is not limited to this.
- a neutral cut valve having a function similar to that of the neutral cut valve 110 may be provided to the second neutral passage 21 instead of or in addition to the neutral cut valve 110 provided to the first neutral passage 11.
- the second circuit system HC2 may be provided with first and second external output passages similar to the first external output passage 14 and the second external output passage 15 of the first circuit system HC1 described in the above embodiments, a sub valve block similar to the sub valve block 103 described in the embodiments may be attached to the main valve block 101, and a circuit system of the sub valve block may be connected to the second circuit system HC2. Furthermore, in the second circuit system HC2, a first external output passage similar to the first external output passage 14 described in the embodiment may be provided, a first external input passage similar to the first external input passage 24 described in the embodiments may be provided to the first circuit system HC1, and the passages may be connected to each other through an external pipe. In this case, the speed of the operation of the first actuator 7 can be increased with the working oil of the second circuit system HC2 joined to the first circuit system HC1, by using the neutral cut valve provided to the second circuit system HC2.
- the fluid pressure control device 100, 200 is a fluid pressure control device for controlling an actuator driven by a working fluid discharged from the pump (first pump 10, 210, second pump 20, 220).
- the fluid pressure control device 100, 200 includes the main circuit system (first circuit system HC1, second circuit system HC2) including the main control valve (first control valve 12, second control valve 22) that is configured to be connected to the pump (first pump 10, 210, second pump 20, 220) and configured to control the main actuator (first actuator 7, second actuator 8).
- the main circuit system (first circuit system HC1, second circuit system HC2) includes the main neutral passage (first neutral passage 11, second neutral passage 21) through which the working fluid discharged from the pump (first pump 10, 210, second pump 20, 220) returns to the tank T when the main control valve (first control valve 12, second control valve 22) is at the neutral position, the neutral cut valve 110 provided on the downstream side of the main control valve (first control valve 12, second control valve 22) in the main neutral passage (first neutral passage 11, second neutral passage 21), the neutral cut valve 110 being configured to make the main neutral passage (first neutral passage 11, second neutral passage 21) and the tank T communicate with each other or block communication between the main neutral passage (first neutral passage 11, second neutral passage 21) and the tank T, the first external output passage 14 through which the working fluid discharged from the pump (first pump 10, 210, second pump 20, 220) is able to be supplied to the outside of the main circuit system, the first external output passage 14 being in communication with the downstream side of the main control valve (first control valve 12, second control valve 22) and the upstream side of the
- the neutral cut valve 110 is switched among the first position (P1) at which the working fluid discharged from the pump (first pump 10, 210, second pump 20, 220) is enabled to be guided to the tank T, the second position (P2) at which the working fluid discharged from the pump (first pump 10, 210, second pump 20, 220) is disabled to be supplied to the outside of the main circuit system through the second external output passage 15 and the working fluid discharged from the pump (first pump 10, 210, second pump 20, 220) is disabled to be guided to the tank T, and the third position (P3) at which the working fluid discharged from the pump (first pump 10, 210, second pump 20, 220) is enabled to be supplied to the outside of the main circuit system through the second external output passage 15 and the working fluid discharged from the pump (first pump 10, 210, second pump 20, 220) is disabled to be guided to the tank T.
- the working oil supplied to the main circuit system (first circuit system HC1, second circuit system HC2) from the pump (first pump 10, 210, second pump 20, 220) can be supplied not only to the first external output passage 14, but can also be supplied to the outside through the second external output passage 15.
- the fluid pressure control device 100, 200 with a high degree of freedom in terms of circuit system expansion can be provided.
- the fluid pressure control device 100, 200 includes the first circuit system HC1 and the second circuit system HC2 as the main circuit system.
- One of the first circuit system HC1 and the second circuit system HC2 is provided with the neutral cut valve 110 and the first external output passage 14, and another of the first circuit system HC1 and the second circuit system HC2 is provided with the first external input passage 24 connected to the first external output passage 14 through the external pipe 30.
- the working fluid can be supplied from one of the first circuit system HC1 and the second circuit system HC2 to the other through the external pipe 30, the speed of the operation of the actuator (first actuator 7, second actuator 8) provided to the other of the first circuit system HC1 and the second circuit system HC2 can be increased.
- the fluid pressure control device 100, 200 further includes the main valve block 101 including the main circuit system (first circuit system HC1 and second circuit system HC2), the sub circuit system (third circuit system HC3, HC32) including the sub control valve (third control valve 32, 232) adapted to control a sub actuator (third actuator 9) by the working fluid discharged from the pump (first pump 10, 210, second pump 20, 220) and supplied to the sub control valve through the main valve block 101, and the sub valve block 103, 203 including the sub circuit system (third circuit system HC3, HC32).
- the sub circuit system (third circuit system HC3, HC32) includes the second external input passage (third neutral passage 31, supply passage 231) connected to the second external output passage 15, and the sub valve block 103, 203 is attachable to the main valve block 101.
- the sub valve block 103, 203 can be attached to the main valve block 101, whereby the installation area of the fluid pressure control device 100, 200 can be made smaller than that in a case where the sub valve block 103, 203 is provided to be separated from the main valve block 101. Furthermore, no pipe needs to be provided between the main valve block 101 and the sub valve block 103, 203, whereby the installation space of the fluid pressure control device 100, 200 can be made small.
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Description
- The present invention relates to a fluid pressure control device.
-
JP2016-204826A JP2016-204826A - As described above, in the fluid pressure control device according to
JP2016-204826A - Further prior art is known from document
JP H09 235759 A - An object of the present invention is to provide a fluid pressure control device with a high degree of freedom in terms of circuit system expansion.
- This object is solved by the subject matter of
claim 1. -
-
FIG. 1 is a circuit diagram illustrating a fluid pressure control device according to a first embodiment of the present invention. -
FIG. 2 is a schematic perspective view of a main valve block and a sub valve block. -
FIG. 3 is a circuit diagram illustrating a fluid pressure control device according to a second embodiment of the present invention. - A fluid
pressure control device 100 according to a first embodiment of the present invention will be described with reference toFIG. 1 andFIG. 2 . - For example, the fluid
pressure control device 100 is used for a working machine such as a power excavator. Here, a case where the working machine is a power excavator will be described. However, the fluidpressure control device 100 can be applied to other working machines such as a wheel loader. In the fluidpressure control device 100, working oil is used as a working fluid. However, other types of fluid such as working water may be used as the working fluid. - Although not elaborated in the figure, the power excavator includes a traveling unit of a crawler type, a swiveling unit that is provided on an upper part of the traveling unit to be able to swivel, and an excavating unit that is provided to the swiveling unit. The traveling unit includes a pair of left and right crawlers. The power excavator travels with the pair of left and right crawlers driven. The excavating unit includes a boom that is pivotally attached to the swiveling unit, an arm that is pivotally attached to the boom, and a bucket that is pivotally attached to the arm.
- As illustrated in
FIG. 1 , the power excavator includes an engine (not illustrated), afirst pump 10 and asecond pump 20 serving as hydraulic pressure pumps that is driven by the engine to discharge the working oil, a fluidpressure control device 100 that controls actuators for driving the traveling unit, the swiveling unit, and the excavating unit by using the working oil discharged from thefirst pump 10 and thesecond pump 20, and a tank T to which the working oil returns from the fluidpressure control device 100. - The fluid
pressure control device 100 controls a plurality of actuators that are driven by the working oil discharged from thefirst pump 10 and thesecond pump 20. Examples of the plurality of actuators include traveling unit drivinghydraulic motors hydraulic cylinder 7B, an auxiliary attachment drivinghydraulic cylinder 8B, an additional attachment drivinghydraulic cylinder 9A, and the like. - Examples of the auxiliary attachment and the additional attachment include a breaker and crusher attached instead of the bucket, an offset device that causes a sliding movement of the boom in a left and right direction, a dozer blade attached to the swiveling unit, and the like.
- The fluid
pressure control device 100 includes: a first circuit system HC1 that is connected to thefirst pump 10 and receives working oil supplied from thefirst pump 10; a second circuit system HC2 that is connected to thesecond pump 20 and receives working oil supplied from thesecond pump 20; and a third circuit system HC3 that is connected to the first circuit system HC1 and receives working oil supplied from thefirst pump 10 via aneutral cut valve 110 described later. As will be described later, a straighttraveling control valve 6 is switched so that the working oil discharged from thefirst pump 10 is also supplied to the second circuit system HC2 and the working oil discharged from thesecond pump 20 is also supplied to the first circuit system HC1 and the third circuit system HC3. - As illustrated in
FIG. 1 andFIG. 2 , the fluidpressure control device 100 includes: amain valve block 101 including the first circuit system HC1 and the second circuit system HC2 serving as a main circuit system; and asub valve block 103 including the third circuit system HC3 serving as a sub circuit system. As illustrated inFIG. 2 , thesub valve block 103 can be attached to themain valve block 101 by using a plurality ofbolts 105. Themain valve block 101 may be formed by stacking and fastening a plurality of valve blocks, or may be formed by a single valve block. - The
main valve block 101 hasbolt attachment holes 115, for attaching thebolts 105, opening in the outer surface. Thesub valve block 103 is fixed to themain valve block 101 with thesub valve block 103 placed on themain valve block 101, shaft portions of thebolts 105 inserted throughbolt insertion holes 135 of thesub valve block 103, and tip portions of the shaft portions of thebolts 105 screwed to thebolt attachment holes 115. - The
sub valve block 103 is provided adapted to control thehydraulic cylinder 9A for driving the additional attachment. Conventionally, to control thehydraulic cylinder 9A for driving the additional attachment, the third circuit system HC3 has been required to be connected to a new hydraulic pump different from thefirst pump 10 or thesecond pump 20, with thesub valve block 103 provided to be separate from themain valve block 101. - On the other hand, according to the present embodiment, the
sub valve block 103 can be attached on themain valve block 101, whereby an installation area of the fluidpressure control device 100 can be reduced. Furthermore, no pipe needs to be provided between themain valve block 101 and thesub valve block 103, whereby an installation space of the fluidpressure control device 100 can be made small. Furthermore, as will be described later, no new hydraulic pump needs to be connected to thesub valve block 103 because the working oil from thefirst pump 10 is supplied to thesub valve block 103 through themain valve block 101. All things considered, according to the present embodiment, the number of parts and cost can be reduced compared with a case where thesub valve block 103 connected with the new hydraulic pump is provided to be separate from themain valve block 101. - As illustrated in
FIG. 1 , the first circuit system HC1 includes: a firstneutral passage 11 serving as a main neutral passage that guides the working oil discharged from thefirst pump 10 to the tank T;first control valves 12 serving as a plurality of main control valves connected in series with the firstneutral passage 11; a firstparallel passage 13 that is branched off from the firstneutral passage 11 more on the upstream side than the straighttraveling control valve 6 described later; and adischarge passage 19 connected to the tank T. The plurality offirst control valves 12 are connected in series through the firstneutral passage 11, and are connected in parallel through the firstparallel passage 13. - The
first control valves 12, which are main control valves adapted to control the actuator provided to the first circuit system HC1, include a firsttraveling control valve 12A, abucket control valve 12B, a boom firstspeed control valve 12C, and an arm secondspeed control valve 12D. The working oil discharged from thefirst pump 10 is guided to the firsttraveling control valve 12A, thebucket control valve 12B, the boom firstspeed control valve 12C, and the arm secondspeed control valve 12D in this order from the upstream side. - The first
traveling control valve 12A is adapted to control supplying/discharging of the working oil to/from the traveling unit drivinghydraulic motor 7A, provided on the left side of the vehicle body of the power excavator. Thebucket control valve 12B is adapted to control supplying/discharging of the working oil to/from the bucket drivinghydraulic cylinder 7B. The boom firstspeed control valve 12C is adapted to control supplying/discharging of the working oil to/from a boom driving hydraulic cylinder (not illustrated). The arm secondspeed control valve 12D is adapted to control supplying/discharging of the working oil to/from an arm driving hydraulic cylinder (not illustrated). The main actuators (such as thehydraulic motor 7A and thehydraulic cylinder 7B) controlled using thefirst control valves 12 are also collectively referred to as afirst actuator 7. - As described above, the first circuit system HC1 includes the plurality of
first control valve 12 that are connected to thefirst pump 10, and are used adapted to control the plurality offirst actuators 7. Thedischarge passage 19 guides the working oil discharged from thefirst actuator 7 via thefirst control valve 12 to the tank T. - In the first circuit system HC1, the working oil discharged from the
first pump 10 returns to the tank T through the firstneutral passage 11, when the straighttraveling control valve 6 described later is at a normal position (A), theneutral cut valve 110 described later is at a first position (P1), and all thefirst control valves 12 are at neutral positions. When at least one of the plurality offirst control valve 12 is at a drive position, the communication between thefirst pump 10 in the firstneutral passage 11 and the tank T is blocked. - In the first circuit system HC1, the working oil discharged from the
first pump 10 can be supplied to thefirst control valves 12B to 12D through the firstparallel passage 13, even when the communication between thefirst pump 10 in the firstneutral passage 11 and the tank T is blocked due to any one of thefirst control valves 12A to 12C being switched to the drive position. - The first circuit system HC1 further includes: the
neutral cut valve 110 that is provided on the downstream side (the downstream side of the arm secondspeed control valve 12D) of all thefirst control valves 12 in the firstneutral passage 11, and adapted to make the firstneutral passage 11 and the tank T communicate with each other or block the communication therebetween; a firstexternal output passage 14; a firstexternal output passage 14 through which the working oil discharged from thefirst pump 10 can be supplied to the outside, the firstexternal output passage 14 being in communication with the downstream side of all thefirst control valves 12 in the first neutral passage 11 (thus, the downstream side of the arm secondspeed control valve 12D) and the upstream side of theneutral cut valve 110; and a secondexternal output passage 15 through which the working oil discharge from thefirst pump 10 and guided via theneutral cut value 110 can be supplied to the outside. - The first
external output passage 14 is connected to a first external output port 14o opening in the outer surface of themain valve block 101. The secondexternal output passage 15 is connected to a second external output port 15o opening in the outer surface of themain valve block 101. The firstparallel passage 13 is connected to an output port 13o opening in the outer surface of themain valve block 101. - The first circuit system HC1 further includes
branch passages discharge passage 19 guiding the working oil to the tank T. Thebranch passages introduction ports main valve block 101. - The
neutral cut valve 110 is a pilot switching valve with a spool switched among the first position (P1), the second position (P2), and the third position (P3) in accordance with pilot pressure supplied to a firstpilot pressure chamber 116a and a secondpilot pressure chamber 116b. The pilot pressure applied to the firstpilot pressure chamber 116a and the secondpilot pressure chamber 116b is controlled on the basis of an operation state of the power excavator, an operation position of a dedicated operation member (not illustrated) for operating theneutral cut valve 110, and the like. - The
neutral cut valve 110 is maintained at the first position (P1) by biasing force from a centeringspring 117, when no pilot pressure is applied to each of the firstpilot pressure chamber 116a and the secondpilot pressure chamber 116b. - The
neutral cut valve 110 includes: afirst inlet port 111 and asecond inlet port 112 that are in communication with the downstream side of the arm secondspeed control valve 12D in the firstneutral passage 11; atank port 119 that is in communication with thedischarge passage 19; and anoutlet port 113 that is in communication with the secondexternal output passage 15. - When the
neutral cut valve 110 is at the first position (P1), thefirst inlet port 111 and thetank port 119 communicate with each other, and the communication between thesecond inlet port 112 and theoutlet port 113 is blocked. When thefirst inlet port 111 and thetank port 119 communicate with each other, the working oil guided to the firstneutral passage 11 is guided to thedischarge passage 19 via theneutral cut valve 110. - Thus, the
neutral cut valve 110 at the first position (P1) disables the supplying of the working oil, discharged from thefirst pump 10, to the outside of themain valve block 101 through the secondexternal output passage 15, and enables the working oil, discharged from thefirst pump 10, to be guided to the tank T through thedischarge passage 19. - When the
neutral cut valve 110 is at the second position (P2), the communication betweenfirst inlet port 111 and thetank port 119 is blocked, and the communication between thesecond inlet port 112 and theoutlet port 113 is blocked. - Thus, the
neutral cut valve 110 at the second position (P2) disables the supplying of the working oil, discharged from thefirst pump 10, to the outside of themain valve block 101 through the secondexternal output passage 15, and disables the working oil, discharged from thefirst pump 10, to be guided to the tank T through thedischarge passage 19. - When the
neutral cut valve 110 is at the third position (P3), the communication between thefirst inlet port 111 andtank port 119 is blocked, and thesecond inlet port 112 and theoutlet port 113 communicate with each other. When thesecond inlet port 112 and theoutlet port 113 communicate with each other, the working oil guided to the firstneutral passage 11 is guided to the secondexternal output passage 15 via theneutral cut valve 110. - Thus, the
neutral cut valve 110 at the third position (P3) enables the working oil, discharged from thefirst pump 10, to be supplied to the outside of themain valve block 101 through the secondexternal output passage 15, and disables the guiding of the working oil, discharged from thefirst pump 10, to the tank T through thedischarge passage 19. - As described above, the first position (P1) is a position with which the first
neutral passage 11 and the tank T communicate with each other, and the second position (P2) and the third position (P3) are position with which the communication between the firstneutral passage 11 and the tank T is blocked. The third position (P3) is a position with which the firstneutral passage 11 and a thirdneutral passage 31 of the third circuit system HC3 described later communicate with each other, and the first position (P1) and the second position (P2) are positions at which the communication between the firstneutral passage 11 and the thirdneutral passage 31 is blocked. - In the present embodiment, the
sub valve block 103 is adapted to be attached to themain valve block 101 so that the working oil discharged from thefirst pump 10 can be further supplied to the third circuit system HC3 through the first circuit system HC1. When thesub valve block 103 is not attached, the ports (13o, 15o, 191i, and 192i) opening in the outer surface of themain valve block 101 are closed by plugs. When thesub valve block 103 is attached, the ports (13o, 15o, 191i, and 192i) opening in the outer surface of themain valve block 101 are connected to the ports (33i, 31i, 38o, and 39o) opening in the outer surface of thesub valve block 103. - The third circuit system HC3 includes: a third
neutral passage 31 that guides the working oil, guided via theneutral cut valve 110 and through the secondexternal output passage 15 in the first circuit system HC1, to the tank T; athird control valve 32 serving as a sub control valve that is connected to the thirdneutral passage 31 and is adapted to control thethird actuator 9 serving as the sub actuator; a thirdparallel passage 33 that guides the working oil, guided through the firstparallel passage 13 in the first circuit system HC1, to thethird control valve 32; and dischargepassages discharge passage 19 in the first circuit system HC1. The thirdneutral passage 31 is connected to the secondexternal output passage 15 in the first circuit system HC1, and functions as a second external input passage to which the working oil is guided through the first circuit system HC1. - In the circuit system formed by connecting the third circuit system HC3 to the first circuit system HC1, the first
neutral passage 11, the secondexternal output passage 15, and the thirdneutral passage 31 function as a neutral passage through which the working oil discharged from thefirst pump 10 returns to the tank T. Specifically, in the circuit system formed by connecting the third circuit system HC3 to the first circuit system HC1, the plurality of first and thethird control valves neutral passage 11, the secondexternal output passage 15, and the thirdneutral passage 31 serving as the neutral passage, and are connected in parallel through the firstparallel passage 13 and the thirdparallel passage 33. - The
third control valve 32 is adapted to control supplying/discharging of the working oil to/from thehydraulic cylinder 9A serving as thethird actuator 9 driving the additional attachment in accordance with the pilot pressure applied to the pilot pressure chamber. Thus, the third circuit system HC3 includes thethird control valve 32 adapted to control thethird actuator 9, using the working oil discharged from thefirst pump 10 and supplied through themain valve block 101. Thethird control valve 32 is an open center type control valve adapted to make the thirdneutral passage 31 and thedischarge passage 39 communicate with each other while being at the neutral position, for guiding the working oil, guided to the thirdneutral passage 31, to the tank T. - The third
neutral passage 31 is connected to theexternal input port 31i opening in the outer surface of thesub valve block 103. Theexternal input port 31i of thesub valve block 103 is connected to the second external output port 15o of themain valve block 101. - The third
parallel passage 33 is connected to theinput port 33i opening in the outer surface of thesub valve block 103. Theinput port 33i of thesub valve block 103 is connected to the output port 13o of themain valve block 101. - The
discharge passage 38 to which the working oil is guided from thehydraulic cylinder 9A via thethird control valve 32 is connected to a draw out port 38o opening in the outer surface of thesub valve block 103. The draw out port 38o of thesub valve block 103 is connected to theintroduction port 191i of themain valve block 101. - The
discharge passage 39 to which the working oil is guided from the thirdneutral passage 31 via thethird control valve 32 is connected to a draw out port 39o opening in the outer surface of thesub valve block 103. The draw out port 39o of thesub valve block 103 is connected to theintroduction port 192i of themain valve block 101. - In the third circuit system HC3, when the
third control valve 32 is at the neutral position, the working oil supplied from the first circuit system HC1 returns to the tank T through the thirdneutral passage 31 and thedischarge passage 39. - The second circuit system HC2 includes: a second
neutral passage 21 serving as a main neutral passage through which the working oil discharged from thesecond pump 20 is guided to the tank T;second control valves 22 serving as plurality of main control valves connected in series with the secondneutral passage 21; a secondparallel passage 23 branched off from the secondneutral passage 21 more on the upstream side than thesecond control valve 22; and adischarge passage 19 connected to the tank T. The plurality ofsecond control valves 22 are connected in series through the secondneutral passage 21, and are connected in parallel through the secondparallel passage 23. - The
second control valves 22 that are main control valves adapted to control actuators provided in the second circuit system HC2 include: a secondtraveling control valve 22A, an auxiliarycorresponding control valve 22B, a swivelingcontrol valve 22C, a boom secondspeed control valve 22D, and an arm firstspeed control valve 22E. The working oil discharged from thesecond pump 20 is guided to the secondtraveling control valve 22A, the auxiliarycorresponding control valve 22B, the swivelingcontrol valve 22C, the boom secondspeed control valve 22D, and the arm firstspeed control valve 22E in this order from the upstream side. - The second
traveling control valve 22A is adapted to control supplying/discharging of the working oil to/from the traveling unit drivinghydraulic motor 8A provided on the right side of the vehicle body of the power excavator. The auxiliarycorresponding control valve 22B is adapted to control supplying/discharging of the working oil to/from the auxiliary attachment drivinghydraulic cylinder 8B. The swivelingcontrol valve 22C is adapted to control supplying/discharging of the working oil to/from a swiveling unit driving hydraulic motor (not illustrated). The boom secondspeed control valve 22D is adapted to control supplying/ discharging of working oil to and from a boom driving hydraulic cylinder (not illustrated). The arm firstspeed control valve 22E is adapted to control supplying/discharging of the working oil to/from an arm driving hydraulic cylinder (not illustrated). The main actuators (such as thehydraulic motor 8A and thehydraulic cylinder 8B) controlled by using thesecond control valves 22 will be also collectively referred to as asecond actuator 8. - As described above, the second circuit system HC2 includes the plurality of
second control valves 22 that is connected to thesecond pump 20 and is adapted to control the plurality ofsecond actuators 8. The working oil discharged from thesecond actuator 8 via thesecond control valve 22 is guided to the tank T through thedischarge passage 19. Thedischarge passage 19 is used as a common passage through which the working oil in the first circuit system HC1 and second circuit system HC2 is guided to the tank T. - In the second circuit system HC2, the working oil discharged from the
second pump 20 returns to the tank T through the secondneutral passage 21 when all thesecond control valves 22 are at the neutral positions. On the other hand, when at least one of the plurality ofsecond control valve 22 is at the drive position, the communication between thesecond pump 20 in the secondneutral passage 21 and the tank T is blocked. - In the second circuit system HC2, the working oil discharged from the
second pump 20 can be supplied to thesecond control valve 22B to 22E through the secondparallel passage 23, even when the communication between thesecond pump 20 in the secondneutral passage 21 and the tank T is blocked due to any one of thesecond control valve 22A to 22D being switched to the drive position. - The second circuit system HC2 includes a first
external input passage 24 through which the working oil, supplied from the outside, is guided to the upstream side of a predetermined second control valve 22 (the auxiliarycorresponding control valve 22B in the present embodiment). The firstexternal input passage 24 is connected to the first external input port 24i opening in the outer surface of themain valve block 101. - The first circuit system HC1 further includes the straight
traveling control valve 6 connected to a point that is more on the downstream side than the point where the firstparallel passage 13 is branched off from the firstneutral passage 11 and more on the upstream side than the firsttraveling control valve 12A. The straighttraveling control valve 6 is connected with a secondparallel passage 23. The secondparallel passage 23 includes a second parallelupstream side passage 23a that connects thesecond pump 20 and the straighttraveling control valve 6 with each other, and a second paralleldownstream side passage 23b that connects the straighttraveling control valve 6 and thesecond control valves 22B to 22E to each other. - The straight
traveling control valve 6 is switched between two positions that are a normal position (A) illustrated on the right side inFIG. 1 and a straight traveling position (B) illustrated on the left side inFIG. 1 . The straighttraveling control valve 6 is switched to the straight traveling position B when the working oil is supplied to thepilot pressure chamber 6a. The straighttraveling control valve 6 is held at the normal position A by the biasing force from areturn spring 6c, when no pilot pressure is applied to thepilot pressure chamber 6a. - When the straight
traveling control valve 6 is at the normal position (A), the second parallelupstream side passage 23a of the secondparallel passage 23 is connected to the second paralleldownstream side passage 23b of the secondparallel passage 23, and the firstneutral passage 11 more on the downstream side than the straighttraveling control valve 6 is connected to thefirst pump 10. Thus, the working oil discharged from thefirst pump 10 is guided to thefirst control valves 12 through the firstneutral passage 11 and the firstparallel passage 13. The working oil discharged from thesecond pump 20 is guided to thesecond control valves 22 through the secondneutral passage 21 and the secondparallel passage 23. - In a state where the
neutral cut valve 110 is at the third position (P3), the working oil discharged from thefirst pump 10 is also guided to thethird control valve 32 through the firstneutral passage 11, via theneutral cut valve 110, and through the secondexternal output passage 15 and the thirdneutral passage 31. The working oil discharged from thefirst pump 10 is also guided to thethird control valve 32 through the firstparallel passage 13 and the thirdparallel passage 33. - When the straight
traveling control valve 6 is at the straight traveling position (B), the second parallelupstream side passage 23a of the secondparallel passage 23 is connected to the firstneutral passage 11 more on the downstream side than the straighttraveling control valve 6, and the second paralleldownstream side passage 23b is connected to thefirst pump 10. Thus, the working oil discharged from thefirst pump 10 is guided to thefirst control valves 12B to 12D through the firstparallel passage 13, and is guided to thesecond control valves 22B to 22E through the second paralleldownstream side passage 23b of the secondparallel passage 23. The working oil discharged from thesecond pump 20 is guided to thefirst control valve 12A through the firstneutral passage 11 more on the downstream side than the straighttraveling control valve 6, and is guided to thesecond control valve 22A through the secondneutral passage 21. - In a state where the
neutral cut valve 110 is at the third position (P3), the working oil discharged from thefirst pump 10 is also guided to thethird control valve 32 through the firstparallel passage 13 and the thirdparallel passage 33. The working oil discharged from thesecond pump 20 is also guided to thethird control valve 32 through the firstneutral passage 11, via theneutral cut valve 110, and through the secondexternal output passage 15 and the thirdneutral passage 31. - In the power excavator traveling in a state with the excavating unit not driven, the
pilot pressure chamber 6a is at tank pressure, and the straighttraveling control valve 6 is maintained at the normal position (A). Thus, when only the traveling unit drivinghydraulic motors first pump 10 is supplied to the firsttraveling control valve 12A and the working oil discharged from thesecond pump 20 is supplied to the secondtraveling control valve 22A. - On the other hand, when the excavating unit actuator is driven while the traveling unit driving
hydraulic motors pilot pressure chamber 6a, so that the straighttraveling control valve 6 is switched to the straight traveling position (B). Thus, when the traveling unit drivinghydraulic motors hydraulic motors second pump 20 is supplied to the firsttraveling control valve 12A and the secondtraveling control valve 22A. Meanwhile, the working oil discharged from thefirst pump 10 is supplied to the otherfirst control valves 12B to 12D, the othersecond control valves 22B to 22E, and thethird control valve 32. Thus, the circuit for traveling and the circuit for a purpose other than traveling are independent from each other, whereby the vehicle body can reliably travel straight. - Next, an operation of the
neutral cut valve 110 will be described. - The
neutral cut valve 110 has the spool positioned at the first position (P1), in a state where the firstpilot pressure chamber 116a and the secondpilot pressure chamber 116b are each connected to the tank T and no working oil is supplied into the firstpilot pressure chamber 116a or the secondpilot pressure chamber 116b. In this state, thefirst inlet port 111 and thetank port 119 communicate with each other, and the communication between thesecond inlet port 112 and theoutlet port 113 is blocked. - Thus, the working oil that has flowed to the
first inlet port 111 through the firstneutral passage 11 is discharged to the tank T through thetank port 119. - When the working oil is supplied to the first
pilot pressure chamber 116a in this state, the spool is moved by the pressure of the working oil supplied to the firstpilot pressure chamber 116a against the biasing force from the centeringspring 117, to switch to the second position (P2). Thus, the communication between thefirst inlet port 111 and thetank port 119 is blocked. The communication between thesecond inlet port 112 and theoutlet port 113 remain to be blocked. - The first external output port 14o is constantly in communication with the first
neutral passage 11 regardless of the position of theneutral cut valve 110. However, in a state where theneutral cut valve 110 is at the first position (P1), the firstneutral passage 11 and the tank T are in communication with each other as described above, whereby the first external output port 14o is also in communication with the tank T. Thus, the working oil discharged from thefirst pump 10 returns to the tank T without being supplied to the outside through the first external output port 14o. - On the other hand, in a state where the
neutral cut valve 110 is at the second position (P2), the communication between the firstneutral passage 11 and the tank T is blocked. Thus, the working oil that has flowed into the firstneutral passage 11 that is on the downstream side of the arm secondspeed control valve 12D and is on the upstream side of theneutral cut valve 110, is entirely supplied to the outside of themain valve block 101 through the firstexternal output passage 14. - As described above, in the fluid
pressure control device 100, the working oil supplied from thefirst pump 10 to the first circuit system HC1 can be supplied to the outside through the first external output port 14o, by switching theneutral cut valve 110 to the second position (P2). - Thus, in the fluid
pressure control device 100, for example, the working oil supplied from thefirst pump 10 to the first circuit system HC1 can be adapted to drive a newly added actuator (not illustrated) or can join the circuit for driving any of thefirst actuator 7, thesecond actuator 8, and thethird actuator 9, through the first external output port 14o. - Now, an example of a case is described where the working oil supplied to the outside through the first external output port 14o joins a flow path of the auxiliary attachment driving
hydraulic cylinder 8B. - The first external output port 14o and the first external input port 24i are connected to each other through an
external pipe 30, outside themain valve block 101. Specifically, the firstexternal output passage 14 is connected to the firstexternal input passage 24 through theexternal pipe 30. - In this state, the working oil is supplied to the pilot pressure chamber of the auxiliary
corresponding control valve 22B adapted to control supplying/discharging of the working oil to/from thehydraulic cylinder 8B, and to the firstpilot pressure chamber 116a of theneutral cut valve 110. Thus, when the auxiliarycorresponding control valve 22B is operated, the working oil discharged from thefirst pump 10 is supplied to the auxiliarycorresponding control valve 22B through the firstexternal output passage 14, theexternal pipe 30, and the firstexternal input passage 24, in addition to the working oil discharged from thesecond pump 20. - Thus, in the present embodiment, the working oil discharged from the
first pump 10 is guided to the outside through the firstexternal output passage 14 of the first circuit system HC1, and is guided to the upstream side of the auxiliarycorresponding control valve 22B through the firstexternal input passage 24 of the second circuit system HC2 to join the working oil discharged from thesecond pump 20. - The
neutral cut valve 110 may be adapted to make the firstneutral passage 11 and the tank T communicate with each other or block the communication therebetween in accordance with pilot pressure Pp adapted to control the auxiliarycorresponding control valve 22B. In this case, the spring load of the centeringspring 117 may be set so that the spool of theneutral cut valve 110 is maintained at the first position (P1) in a state where the pilot pressure Pp is low, and the spool of theneutral cut valve 110 is switched to the second position (P2) in a state where the pilot pressure Pp is high. - With this configuration, the
hydraulic cylinder 8B is driven by the working oil discharged from thesecond pump 20 only, when the operation amount of the auxiliarycorresponding control valve 22B is small. Thehydraulic cylinder 8B is driven by the working oil discharged from thefirst pump 10 in addition to the working oil discharged from thesecond pump 20, when the operation amount of the auxiliarycorresponding control valve 22B is large. - Thus, by increasing the operation amount of the auxiliary
corresponding control valve 22B, the flow rate of the working oil for the auxiliarycorresponding control valve 22B can be increased, whereby the speed of the operation of thehydraulic cylinder 8B controlled by the auxiliarycorresponding control valve 22B can be increased. - Although not elaborated in the figure, in a case where the working oil is supplied to a circuit system for driving a newly added actuator through the first
external output passage 14, theneutral cut valve 110 may be switched to the second position (P2) when the additional actuator is driven. - On the other hand, when the working oil is supplied to the second
pilot pressure chamber 116b of theneutral cut valve 110, the spool is moved by the pressure of the working oil supplied to the secondpilot pressure chamber 116b against the biasing force from the centeringspring 117, to switch to the third position (P3). As a result, thesecond inlet port 112 and theoutlet port 113 communicate with each other, and the communication between thefirst inlet port 111 and thetank port 119 is blocked. - In a state where the
neutral cut valve 110 is at the third position (P3), the thirdneutral passage 31 of the third circuit system HC3 is in communication with the firstneutral passage 11 of the first circuit system HC1. The thirdparallel passage 33 of the third circuit system HC3 is constantly in communication with the firstparallel passage 13 of the first circuit system HC1. - Thus, in the state where the
neutral cut valve 110 is at the third position (P3), the plurality of first andthird control valves neutral passage 11, the secondexternal output passage 15, and thirdneutral passage 31 serving as the neutral passage, and is connected in parallel through the firstparallel passage 13 and the thirdparallel passage 33. - Thus, in the state where the
neutral cut valve 110 is at the third position (P3), the working oil discharged from thefirst pump 10 can be supplied to thethird control valve 32 through the firstparallel passage 13 and the thirdparallel passage 33, even when the communication between thefirst pump 10 in the firstneutral passage 11 and the tank T is blocked with any of or all of thefirst control valves 12A to 12D being switched to the drive position. - Thus, with the
sub valve block 103 attached to themain valve block 101, thethird actuator 9 that can be driven, similarly to thefirst actuator 7, using the working oil discharged from thefirst pump 10 or thesecond pump 20 can be easily added. - The embodiment described above can provide the following effects.
- By switching the
neutral cut valve 110 to the second position (P2), the working oil discharged from thefirst pump 10 can be supplied to the outside of themain valve block 101 through the firstexternal output passage 14. By switching theneutral cut valve 110 to the third position (P3), the working oil discharged from thefirst pump 10 can be supplied to the outside of themain valve block 101 through the secondexternal output passage 15. - Thus, the working oil supplied to the first circuit system HC1 from the
first pump 10 can be supplied not only to the firstexternal output passage 14, but can also be supplied to the outside through the secondexternal output passage 15, whereby the fluidpressure control device 100 with a high degree of freedom in terms of circuit system expansion can be provided. - A fluid
pressure control device 200 according to a second embodiment of the present invention will be described with reference toFIG. 3 . The points different from the first embodiment will be mainly described below, and the configuration that is the same as or corresponding to the configurations described in the first embodiment will be denoted with the same reference numerals and the description thereof will be omitted. - In the example described in the first embodiment, the third circuit system HC3 includes the
third control valve 32 of an open center type. On the other hand, in the second embodiment, the third circuit system HC32 includes athird control valve 232 of a closed center type. - In the second embodiment, the configurations of the first circuit system HC1 and the second circuit system HC2 are similar to those in the first embodiment, but the configuration of the third circuit system HC32 is different from that in the first embodiment. Thus, the second embodiment is similar to the first embodiment in the configuration of the
main valve block 101, but is different from the first embodiment in the configuration of thesub valve block 203. - The
sub valve block 203 including the third circuit system HC32 includes an inlet block B30 through which the working oil from the first circuit system HC1 is taken in, and valve blocks B31 and B32 adapted to control the additional attachment drivingthird actuator 9. The inlet block B30 also serves as an outlet block for discharging the working oil to the tank T. The valve block B31 has a configuration similar to that of the valve block B32. Thus, the valve block B32 is partially omitted in the drawing. The number of valve blocks can be changed as appropriate in accordance with the number of actuators to be added. - The third circuit system HC32 includes: a plurality of
third control valves 232 adapted to control a plurality ofthird actuators 9; asupply passage 231 serving as a second external input passage connected to the secondexternal output passage 15 of the first circuit system HC1; atank passage 239 connected to the tank T; and aload pressure passage 241 to which the highest load pressure among those of the plurality ofthird actuators 9 is guided. Thesupply passage 231 is for guiding the working oil that has been discharged from thefirst pump 210 and supplied thereto through the firstneutral passage 11, theneutral cut valve 110, and the secondexternal output passage 15 to thethird control valve 232. Thethird control valve 232 is adapted to control thethird actuator 9 by the working oil discharged from thefirst pump 210 and supplied to thesupply passage 231 through themain valve block 101. - The inlet block B30 is provided with a discharge
pressure output port 231p connected to thesupply passage 231 and a loadpressure output port 241p connected to theload pressure passage 241. The inlet block B30 is provided with arelief valve 261 connected to thesupply passage 231. When theneutral cut valve 110 is at the third position (P3), therelief valve 261 defines the maximum pressure of the circuit formed by connecting the third circuit system HC3 of thesub valve block 203 to the first circuit system HC1 of themain valve block 101. - The valve blocks B31 and B32 each include a
third control valve 232 connected to thesupply passage 231, and apressure compensation valve 234 provided between thethird control valve 232 and thethird actuator 9. - The present embodiment employs a load sensing system of an after orifice type, with the
pressure compensation valve 234 provided on the downstream side of a meter in throttle portion of thethird control valves 232. In such a load sensing system, when more than one of thethird actuator 9 are concurrently operated, thepressure compensation valve 234 functions to adjust loads among thethird actuators 9. - The
pressure compensation valve 234 is provided with pressure on the downstream side of the meter in throttle portion provided to thethird control valve 232 and the highest load pressure among those of the plurality ofthird actuators 9. Thepressure compensation valve 234 is for compensation with which the pressure on the downstream side of the meter in throttle portion becomes higher than the highest load pressure of thethird actuators 9 by a predetermined amount. - Thus, in the present embodiment, the hydraulic oil with the flow rate corresponding to the operation amount of the spool of the
third control valve 232 regardless of a difference in load pressure among thethird actuators 9, when the plurality ofthird control valve 232 are concurrently driven. - The
first pump 210 and thesecond pump 220 are variable capacity piston pumps, with the discharge capacity varying in accordance with a change in the inclination of a swash plate made by a regulator (not illustrated). The discharge capacity of thefirst pump 210 and thesecond pump 220 are controlled by what is known as load sensing control, so that a predetermined value is obtained as a difference between the pump discharge pressure guided to the regulator (not illustrated) and the maximum load pressure of thethird actuators 9. - The maximum load pressure of the
third actuators 9 is guided to the regulator (not illustrated) of thefirst pump 210 andsecond pump 220 from the loadpressure output port 241p through a pipe and the like. The pump discharge pressure is guided to the regulator (not illustrated) of thefirst pump 210 andsecond pump 220 from the dischargepressure output port 231p through a pipe and the like. - In the second embodiment, the output port 13o and the
introduction ports main valve block 101 are closed by thesub valve block 203. With the unused ports (13o, 191i, and 192i) closed by thesub valve block 203, a closing member such as a plug needs not to be additionally provided, whereby the number of parts can be reduced. - Such a second embodiment can be provided an advantageous effect that is similar to that of the first embodiment.
- As described above, the
main valve block 101 according to the second embodiment is similar to that in the first embodiment. Thus, themain valve block 101 is compatible with any of open center type (seeFIG. 1 ) and of closed center type (seeFIG. 3 )third control valves neutral cut valve 110 as well as the predetermined ports (15o, 13o, 191i, and 192i) provided, themain valve block 101 featuring high versatility can be provided. - Modifications as described below also fall within the scope of the present invention. Configurations illustrated in the modifications can be combined with configurations illustrated in the above-described embodiments. Configurations illustrated in different embodiments described above can be combined. Configurations illustrated in different modifications described below can be combined.
- In the examples described in the embodiments, the
first actuator 7 and thefirst control valve 12 are each provided in a plurality. However, the present invention is not limited to this. It suffices if at least onefirst actuator 7 and at least onefirst control valve 12 are provided. In the example described in the embodiment, thesecond actuator 8 and thesecond control valve 22 are each provided in a plurality. However, the present invention is not limited to this. It suffices if at least onesecond actuator 8 and at least onesecond control valve 22 are provided. - In the examples described in the embodiments, the first
neutral passage 11 of the first circuit system HC1 is provided with theneutral cut valve 110. However, the present invention is not limited to this. A neutral cut valve having a function similar to that of theneutral cut valve 110 may be provided to the secondneutral passage 21 instead of or in addition to theneutral cut valve 110 provided to the firstneutral passage 11. - Specifically, the second circuit system HC2 may be provided with first and second external output passages similar to the first
external output passage 14 and the secondexternal output passage 15 of the first circuit system HC1 described in the above embodiments, a sub valve block similar to thesub valve block 103 described in the embodiments may be attached to themain valve block 101, and a circuit system of the sub valve block may be connected to the second circuit system HC2. Furthermore, in the second circuit system HC2, a first external output passage similar to the firstexternal output passage 14 described in the embodiment may be provided, a first external input passage similar to the firstexternal input passage 24 described in the embodiments may be provided to the first circuit system HC1, and the passages may be connected to each other through an external pipe. In this case, the speed of the operation of thefirst actuator 7 can be increased with the working oil of the second circuit system HC2 joined to the first circuit system HC1, by using the neutral cut valve provided to the second circuit system HC2. - The configuration, actions and effects of the embodiments of the present invention configured as described above will be described collectively.
- The fluid
pressure control device first pump second pump 20, 220). The fluidpressure control device first control valve 12, second control valve 22) that is configured to be connected to the pump (first pump second pump 20, 220) and configured to control the main actuator (first actuator 7, second actuator 8). The main circuit system (first circuit system HC1, second circuit system HC2) includes the main neutral passage (first neutral passage 11, second neutral passage 21) through which the working fluid discharged from the pump (first pump 10, 210, second pump 20, 220) returns to the tank T when the main control valve (first control valve 12, second control valve 22) is at the neutral position, the neutral cut valve 110 provided on the downstream side of the main control valve (first control valve 12, second control valve 22) in the main neutral passage (first neutral passage 11, second neutral passage 21), the neutral cut valve 110 being configured to make the main neutral passage (first neutral passage 11, second neutral passage 21) and the tank T communicate with each other or block communication between the main neutral passage (first neutral passage 11, second neutral passage 21) and the tank T, the first external output passage 14 through which the working fluid discharged from the pump (first pump 10, 210, second pump 20, 220) is able to be supplied to the outside of the main circuit system, the first external output passage 14 being in communication with the downstream side of the main control valve (first control valve 12, second control valve 22) and the upstream side of the neutral cut valve 110 in the main neutral passage (first neutral passage 11, second neutral passage 21), and the second external output passage 15 through which the working fluid discharged from the pump (first pump 10, 210, second pump 20, 220) and guided via the neutral cut valve 110 is able to be supplied to the outside of the main circuit system. - The
neutral cut valve 110 is switched among the first position (P1) at which the working fluid discharged from the pump (first pump second pump 20, 220) is enabled to be guided to the tank T, the second position (P2) at which the working fluid discharged from the pump (first pump second pump 20, 220) is disabled to be supplied to the outside of the main circuit system through the secondexternal output passage 15 and the working fluid discharged from the pump (first pump second pump 20, 220) is disabled to be guided to the tank T, and the third position (P3) at which the working fluid discharged from the pump (first pump second pump 20, 220) is enabled to be supplied to the outside of the main circuit system through the secondexternal output passage 15 and the working fluid discharged from the pump (first pump second pump 20, 220) is disabled to be guided to the tank T. - With this configuration, the working oil supplied to the main circuit system (first circuit system HC1, second circuit system HC2) from the pump (
first pump second pump 20, 220) can be supplied not only to the firstexternal output passage 14, but can also be supplied to the outside through the secondexternal output passage 15. Thus, the fluidpressure control device - The fluid
pressure control device neutral cut valve 110 and the firstexternal output passage 14, and another of the first circuit system HC1 and the second circuit system HC2 is provided with the firstexternal input passage 24 connected to the firstexternal output passage 14 through theexternal pipe 30. - With this configuration, since the working fluid can be supplied from one of the first circuit system HC1 and the second circuit system HC2 to the other through the
external pipe 30, the speed of the operation of the actuator (first actuator 7, second actuator 8) provided to the other of the first circuit system HC1 and the second circuit system HC2 can be increased. - The fluid
pressure control device main valve block 101 including the main circuit system (first circuit system HC1 and second circuit system HC2), the sub circuit system (third circuit system HC3, HC32) including the sub control valve (third control valve 32, 232) adapted to control a sub actuator (third actuator 9) by the working fluid discharged from the pump (first pump second pump 20, 220) and supplied to the sub control valve through themain valve block 101, and thesub valve block neutral passage 31, supply passage 231) connected to the secondexternal output passage 15, and thesub valve block main valve block 101. - With this configuration, the
sub valve block main valve block 101, whereby the installation area of the fluidpressure control device sub valve block main valve block 101. Furthermore, no pipe needs to be provided between themain valve block 101 and thesub valve block pressure control device
Claims (3)
- A fluid pressure control device (100, 200) for controlling an actuator driven by a working fluid discharged from a pump, comprising:a main circuit system (HC1, HC2) including a main control valve (12, 22) that is configured to be connected to the pump and configured to control a main actuator (7, 8), whereinthe main circuit system (HC1, HC2) includes:a main neutral passage (11, 21) through which the working fluid discharged from the pump returns to a tank (T) when the main control valve (12, 22) is at a neutral position;a neutral cut valve (110) provided on a downstream side of the main control valve (12, 22) in the main neutral passage (12, 22), the neutral cut valve (110) being configured to make the main neutral passage (11, 21) and the tank (T) communicate with each other or block communication between the neutral passage (11, 21) and the tank (T);a first external output passage (14) through which the working fluid discharged from the pump is able to be supplied to the outside of the main circuit system (HC1,HC2), the first external output passage (14) being in communication with the downstream side of the main control valve (12, 22) and an upstream side of the neutral cut valve (110) in the main neutral passage (11, 21); anda second external output passage (15) through which the working fluid discharged from the pump and guided via the neutral cut valve (110) is able to be supplied to the outside of the main circuit system (HC1, HC2), andthe neutral cut valve (110) is switched amonga first position (P1) at which the working fluid discharged from the pump is enabled to be guided to the tank (T),a second position (P2) at which the working fluid discharged from the pump is disabled to be supplied to the outside of the main circuit system (HC1, HC2) through the second external output passage (15) and the working fluid discharged from the pump is disabled to be guided to the tank (T), anda third position (P3) at which the working fluid discharged from the pump is enabled to be supplied to the outside of the main circuit system (HC1, HC2) through the second external output passage (15) and the working fluid discharged from the pump is disabled to be guided to the tank (T).
- The fluid pressure control device (100, 200) according to claim 1, comprising:a first circuit system (HC1) and a second circuit system (HC2) serving as the main circuit system, whereinone of the first circuit system (HC1) and the second circuit system (HC2) is provided with the neutral cut valve (110) and the first external output passage (14), andanother one of the first circuit system (HC1) and the second circuit system (HC2) is provided with a first external input passage (24) connected to the first external output passage (14) through an external pipe (30).
- The fluid pressure control device (100, 200) according to claim 1 or 2, further comprising:a main valve block (101) including the main circuit system (HC1, HC2);a sub circuit system (HC3, HC32) including a sub control valve (32, 232) adapted to control a sub actuator (9) by the working fluid discharged from the pump and supplied to the sub control valve (32, 232) through the main valve block (101); anda sub valve block (103, 203) including the sub circuit system (HC3, HC32), whereinthe sub circuit system (HC3, HC32) includes a second external input passage (31, 231) connected to the second external output passage (15), and the sub valve block (103, 203) is attachable to the main valve block (101).
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP2018217345A JP7121641B2 (en) | 2018-11-20 | 2018-11-20 | Fluid pressure controller |
PCT/JP2019/030975 WO2020105230A1 (en) | 2018-11-20 | 2019-08-06 | Fluid pressure control device |
Publications (3)
Publication Number | Publication Date |
---|---|
EP3686440A1 EP3686440A1 (en) | 2020-07-29 |
EP3686440A4 EP3686440A4 (en) | 2021-07-21 |
EP3686440B1 true EP3686440B1 (en) | 2022-10-26 |
Family
ID=70774020
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
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EP19872249.8A Active EP3686440B1 (en) | 2018-11-20 | 2019-08-06 | Fluid pressure control device |
Country Status (5)
Country | Link |
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EP (1) | EP3686440B1 (en) |
JP (1) | JP7121641B2 (en) |
KR (1) | KR102503136B1 (en) |
CN (1) | CN111556929B (en) |
WO (1) | WO2020105230A1 (en) |
Family Cites Families (14)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US4142445A (en) * | 1977-03-17 | 1979-03-06 | Caterpillar Tractor Co. | Crossover plural circuit fluid system |
JPH04312630A (en) * | 1991-04-11 | 1992-11-04 | Hitachi Constr Mach Co Ltd | Hydraulic circuit for construction equipment |
JPH07238575A (en) * | 1994-02-28 | 1995-09-12 | Komatsu Ltd | Hydraulic device for running |
JP2896071B2 (en) * | 1994-04-20 | 1999-05-31 | シーケーディ株式会社 | Pilot check valve |
JP3244257B2 (en) * | 1995-12-28 | 2002-01-07 | 新キャタピラー三菱株式会社 | Work machine control circuit of work machine |
JP3597693B2 (en) * | 1998-02-18 | 2004-12-08 | 日立建機株式会社 | Hydraulic drive circuit |
JP3699587B2 (en) * | 1998-03-06 | 2005-09-28 | 東芝機械株式会社 | Multiple hydraulic valve |
JP3971879B2 (en) * | 1999-11-29 | 2007-09-05 | カヤバ工業株式会社 | Multiple valves |
JP2001295803A (en) * | 2000-04-10 | 2001-10-26 | Hitachi Constr Mach Co Ltd | Hydraulic driving device for work machine |
CN202012523U (en) * | 2011-04-18 | 2011-10-19 | 陈子行 | Split hydraulic system of all hydraulic tunnel drilling machine |
CN102996560B (en) * | 2012-12-28 | 2015-06-24 | 中联重科股份有限公司 | Pumping device and valve block |
CN103174696B (en) * | 2013-03-21 | 2015-12-23 | 徐工集团工程机械股份有限公司 | Valve body integrated device and crawler belt type dynamic compaction machine |
CN103697007B (en) * | 2013-12-20 | 2016-06-01 | 中国北方车辆研究所 | A kind of valve group based on control enclosed system |
JP6491523B2 (en) * | 2015-04-15 | 2019-03-27 | Kyb株式会社 | Fluid pressure control device |
-
2018
- 2018-11-20 JP JP2018217345A patent/JP7121641B2/en active Active
-
2019
- 2019-08-06 WO PCT/JP2019/030975 patent/WO2020105230A1/en unknown
- 2019-08-06 EP EP19872249.8A patent/EP3686440B1/en active Active
- 2019-08-06 CN CN201980007254.7A patent/CN111556929B/en active Active
- 2019-08-06 KR KR1020207011775A patent/KR102503136B1/en active IP Right Grant
Also Published As
Publication number | Publication date |
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WO2020105230A1 (en) | 2020-05-28 |
CN111556929A (en) | 2020-08-18 |
EP3686440A1 (en) | 2020-07-29 |
CN111556929B (en) | 2022-07-19 |
KR102503136B1 (en) | 2023-02-23 |
KR20200061372A (en) | 2020-06-02 |
JP2020085077A (en) | 2020-06-04 |
JP7121641B2 (en) | 2022-08-18 |
EP3686440A4 (en) | 2021-07-21 |
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