WO2022201792A1 - 作業機械 - Google Patents
作業機械 Download PDFInfo
- Publication number
- WO2022201792A1 WO2022201792A1 PCT/JP2022/001835 JP2022001835W WO2022201792A1 WO 2022201792 A1 WO2022201792 A1 WO 2022201792A1 JP 2022001835 W JP2022001835 W JP 2022001835W WO 2022201792 A1 WO2022201792 A1 WO 2022201792A1
- Authority
- WO
- WIPO (PCT)
- Prior art keywords
- pressure
- control valve
- differential pressure
- accumulator
- control device
- Prior art date
Links
- 238000001514 detection method Methods 0.000 claims abstract description 11
- 238000009825 accumulation Methods 0.000 abstract description 13
- 230000007423 decrease Effects 0.000 abstract description 5
- 239000003921 oil Substances 0.000 description 86
- 239000010720 hydraulic oil Substances 0.000 description 29
- 238000004364 calculation method Methods 0.000 description 18
- 238000004891 communication Methods 0.000 description 13
- 239000012530 fluid Substances 0.000 description 13
- 238000010586 diagram Methods 0.000 description 12
- 230000004048 modification Effects 0.000 description 10
- 238000012986 modification Methods 0.000 description 10
- 238000011084 recovery Methods 0.000 description 9
- 238000006243 chemical reaction Methods 0.000 description 8
- 230000006870 function Effects 0.000 description 7
- 238000011144 upstream manufacturing Methods 0.000 description 6
- 230000000052 comparative effect Effects 0.000 description 5
- 230000007935 neutral effect Effects 0.000 description 5
- 230000008602 contraction Effects 0.000 description 2
- 238000007599 discharging Methods 0.000 description 2
- 238000009412 basement excavation Methods 0.000 description 1
- 238000002485 combustion reaction Methods 0.000 description 1
- 238000005056 compaction Methods 0.000 description 1
- 238000010276 construction Methods 0.000 description 1
- 238000006073 displacement reaction Methods 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 238000000034 method Methods 0.000 description 1
- 230000002093 peripheral effect Effects 0.000 description 1
- 238000005381 potential energy Methods 0.000 description 1
- 230000004044 response Effects 0.000 description 1
- 230000000630 rising effect Effects 0.000 description 1
- 238000005096 rolling process Methods 0.000 description 1
- 239000004576 sand Substances 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
- E02F9/08—Superstructures; Supports for superstructures
- E02F9/10—Supports for movable superstructures mounted on travelling or walking gears or on other superstructures
- E02F9/12—Slewing or traversing gears
- E02F9/121—Turntables, i.e. structure rotatable about 360°
- E02F9/123—Drives or control devices specially adapted 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
- E02F9/2217—Hydraulic or pneumatic drives with energy recovery arrangements, e.g. using accumulators, flywheels
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- E—FIXED CONSTRUCTIONS
- E02—HYDRAULIC ENGINEERING; FOUNDATIONS; SOIL SHIFTING
- E02F—DREDGING; SOIL-SHIFTING
- E02F9/00—Component parts of dredgers or soil-shifting machines, not restricted to one of the kinds covered by groups E02F3/00 - E02F7/00
- E02F9/20—Drives; Control devices
- E02F9/22—Hydraulic or pneumatic drives
- E02F9/2221—Control of flow rate; Load sensing arrangements
- E02F9/2225—Control of flow rate; Load sensing arrangements using pressure-compensating valves
- E02F9/2228—Control of flow rate; Load sensing arrangements using pressure-compensating valves including an electronic controller
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- E—FIXED CONSTRUCTIONS
- E02—HYDRAULIC ENGINEERING; FOUNDATIONS; SOIL SHIFTING
- E02F—DREDGING; SOIL-SHIFTING
- E02F9/00—Component parts of dredgers or soil-shifting machines, not restricted to one of the kinds covered by groups E02F3/00 - E02F7/00
- E02F9/20—Drives; Control devices
- E02F9/22—Hydraulic or pneumatic drives
- E02F9/2221—Control of flow rate; Load sensing arrangements
- E02F9/2232—Control of flow rate; Load sensing arrangements using one or more variable displacement pumps
- E02F9/2235—Control of flow rate; Load sensing arrangements using one or more variable displacement pumps including an electronic controller
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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
- E02F9/2242—Control of flow rate; Load sensing arrangements using two or more pumps with cross-assistance including an electronic controller
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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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- 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
- F15B1/00—Installations or systems with accumulators; Supply reservoir or sump assemblies
- F15B1/02—Installations or systems with accumulators
- F15B1/024—Installations or systems with accumulators used as a supplementary power source, e.g. to store energy in idle periods to balance pump load
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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
- F15B11/02—Systems essentially incorporating special features for controlling the speed or actuating force of an output member
- F15B11/028—Systems essentially incorporating special features for controlling the speed or actuating force of an output member for controlling the actuating force
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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
- F15B11/02—Systems essentially incorporating special features for controlling the speed or actuating force of an output member
- F15B11/04—Systems essentially incorporating special features for controlling the speed or actuating force of an output member for controlling the speed
- F15B11/05—Systems essentially incorporating special features for controlling the speed or actuating force of an output member for controlling the speed specially adapted to maintain constant speed, e.g. pressure-compensated, load-responsive
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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
- F15B21/00—Common features of fluid actuator systems; Fluid-pressure actuator systems or details thereof, not covered by any other group of this subclass
- F15B21/14—Energy-recuperation means
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B60—VEHICLES IN GENERAL
- B60Y—INDEXING SCHEME RELATING TO ASPECTS CROSS-CUTTING VEHICLE TECHNOLOGY
- B60Y2200/00—Type of vehicle
- B60Y2200/40—Special vehicles
- B60Y2200/41—Construction vehicles, e.g. graders, excavators
- B60Y2200/412—Excavators
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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
- F15B2211/20546—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
- F15B2211/20—Fluid pressure source, e.g. accumulator or variable axial piston pump
- F15B2211/205—Systems with pumps
- F15B2211/20576—Systems with pumps with multiple pumps
- F15B2211/20592—Combinations of pumps for supplying high and low 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
- F15B2211/20—Fluid pressure source, e.g. accumulator or variable axial piston pump
- F15B2211/21—Systems with pressure sources other than pumps, e.g. with a pyrotechnical charge
- F15B2211/212—Systems with pressure sources other than pumps, e.g. with a pyrotechnical charge the pressure sources being accumulators
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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
- F15B2211/30565—Assemblies of multiple valves having multiple valves for a single output member, e.g. for creating higher valve function by use of multiple valves like two 2/2-valves replacing a 5/3-valve
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
- F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
- F15B2211/00—Circuits for servomotor systems
- F15B2211/30—Directional control
- F15B2211/305—Directional control characterised by the type of valves
- F15B2211/3056—Assemblies of multiple valves
- F15B2211/30565—Assemblies of multiple valves having multiple valves for a single output member, e.g. for creating higher valve function by use of multiple valves like two 2/2-valves replacing a 5/3-valve
- F15B2211/3057—Assemblies of multiple valves having multiple valves for a single output member, e.g. for creating higher valve function by use of multiple valves like two 2/2-valves replacing a 5/3-valve having two valves, one for each port of a double-acting 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
- F15B2211/305—Directional control characterised by the type of valves
- F15B2211/3056—Assemblies of multiple valves
- F15B2211/30565—Assemblies of multiple valves having multiple valves for a single output member, e.g. for creating higher valve function by use of multiple valves like two 2/2-valves replacing a 5/3-valve
- F15B2211/3058—Assemblies of multiple valves having multiple valves for a single output member, e.g. for creating higher valve function by use of multiple valves like two 2/2-valves replacing a 5/3-valve having additional valves for interconnecting the fluid chambers of a double-acting actuator, e.g. for regeneration mode or for floating mode
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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
- F15B2211/3144—Directional control characterised by the positions of the valve element the positions being continuously variable, e.g. as realised by proportional 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
- F15B2211/30—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
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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
- F15B2211/31552—Directional control characterised by the connections of the valve or valves in the circuit being connected to an output member and a 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
- F15B2211/30—Directional control
- F15B2211/32—Directional control characterised by the type of actuation
- F15B2211/327—Directional control characterised by the type of actuation electrically or electronically
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
- F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
- F15B2211/00—Circuits for servomotor systems
- F15B2211/50—Pressure control
- F15B2211/505—Pressure control characterised by the type of pressure control means
- F15B2211/50509—Pressure control characterised by the type of pressure control means the pressure control means controlling a pressure upstream of the pressure control means
- F15B2211/50518—Pressure control characterised by the type of pressure control means the pressure control means controlling a pressure upstream of the pressure control means using pressure relief valves
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
- F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
- F15B2211/00—Circuits for servomotor systems
- F15B2211/50—Pressure control
- F15B2211/505—Pressure control characterised by the type of pressure control means
- F15B2211/50563—Pressure control characterised by the type of pressure control means the pressure control means controlling a differential 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
- F15B2211/50—Pressure control
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- F15B2211/513—Pressure control characterised by the positions of the valve element the positions being continuously variable, e.g. as realised by proportional 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
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- F15B2211/5153—Pressure control characterised by the connections of the pressure control means in the circuit being connected to an output member and a directional control valve
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
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- 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
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- F15B2211/5158—Pressure control characterised by the connections of the pressure control means in the circuit being connected to a pressure source and an output member
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
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- F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
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- F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
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- F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
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- 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
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- F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
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- F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
- F15B2211/00—Circuits for servomotor systems
- F15B2211/60—Circuit components or control therefor
- F15B2211/63—Electronic controllers
- F15B2211/6303—Electronic controllers using input signals
- F15B2211/6346—Electronic controllers using input signals representing a state of input means, e.g. joystick position
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
- F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
- F15B2211/00—Circuits for servomotor systems
- F15B2211/60—Circuit components or control therefor
- F15B2211/665—Methods of control using electronic components
- F15B2211/6653—Pressure control
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
- F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
- F15B2211/00—Circuits for servomotor systems
- F15B2211/70—Output members, e.g. hydraulic motors or cylinders or control therefor
- F15B2211/705—Output members, e.g. hydraulic motors or cylinders or control therefor characterised by the type of output members or actuators
- F15B2211/7051—Linear output members
- F15B2211/7053—Double-acting 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
- F15B2211/70—Output members, e.g. hydraulic motors or cylinders or control therefor
- F15B2211/705—Output members, e.g. hydraulic motors or cylinders or control therefor characterised by the type of output members or actuators
- F15B2211/7058—Rotary 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
- F15B2211/70—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
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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
- F15B2211/75—Control of speed of the 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
- F15B2211/80—Other types of control related to particular problems or conditions
- F15B2211/88—Control measures for saving energy
Definitions
- the present invention relates to a working machine such as a hydraulic excavator equipped with an accumulator.
- Patent Document 1 discloses a hydraulic circuit in which a swing motor drive circuit communicates with a swing energy recovery passage via a check valve, and the swing energy recovery passage is connected to an accumulator via a sequence valve. ing.
- the differential pressure generated by the sequence valve described in Patent Document 1 is determined by the spring force to a preset value. Therefore, when the pressure oil discharged from the swing motor is accumulated in the accumulator, if the back pressure on the accumulator side of the sequence valve changes, the original pressure on the inlet side of the sequence valve changes and the operation of the swing motor becomes unstable. may become
- An object of the present invention is to provide a work machine that can stably operate a hydraulic actuator when accumulating pressure oil discharged from the hydraulic actuator in a pressure accumulator.
- a work machine includes an engine, a hydraulic pump driven by the engine and discharging pressure oil, a hydraulic actuator operated by the pressure oil discharged by the hydraulic pump, and a hydraulic pressure discharged from the hydraulic actuator.
- a pressure accumulator for accumulating pressure oil
- a differential pressure control valve provided between the hydraulic actuator and the pressure accumulator for generating a differential pressure between the pressure of the hydraulic actuator and the pressure of the pressure accumulator
- a pressure sensor that detects the pressure of the device, and a control device that controls the differential pressure control valve based on the detection result of the pressure sensor.
- the control device controls the differential pressure control valve so that the differential pressure across the pressure sensor decreases in accordance with an increase in the pressure of the pressure accumulator detected by the pressure sensor.
- FIG. 1 is a side view of the hydraulic excavator according to the first embodiment.
- FIG. 2 is a diagram showing a hydraulic system provided in the hydraulic excavator according to the first embodiment.
- FIG. 3 is a hardware configuration diagram of the control device.
- FIG. 4 is a block diagram showing control of the differential pressure control valve by the control device according to the first embodiment.
- FIG. 5 is a diagram showing a hydraulic system provided in a hydraulic excavator according to the second embodiment.
- FIG. 6 is a block diagram showing control of the differential pressure control valve by the control device according to the second embodiment.
- FIG. 7 is a diagram showing a hydraulic system included in a hydraulic excavator according to Modification 1.
- FIG. FIG. 8 is a block diagram showing control of the first boom control valve by the control device according to the third embodiment.
- a working machine according to an embodiment of the present invention will be described with reference to the drawings.
- the work machine is a crawler hydraulic excavator
- the work machines perform works such as civil engineering work, construction work, demolition work, and dredging work at work sites.
- FIG. 1 is a side view of a hydraulic excavator 100 according to the first embodiment.
- the hydraulic excavator 100 includes a body 105 and a working device 104 attached to the body 105 .
- the body 105 has a crawler-type running body 102 and a revolving body 103 provided on the running body 102 so as to be able to turn.
- the traveling body 102 travels by driving a pair of left and right crawlers with a traveling motor 102A.
- the revolving body 103 is connected to the traveling body 102 via a revolving device having a revolving motor 103A, and is driven by the revolving motor 103A to revolve with respect to the running body 102 .
- the revolving structure 103 includes a driver's cab 118 in which an operator rides, and an engine room 119 in which an engine 32 as a prime mover and hydraulic equipment such as a hydraulic pump driven by the engine 32 are accommodated.
- an electric operation device is provided for operating the hydraulic actuators (111A, 112A, 113A, 103A, 102A) of the working device 104, the revolving body 103 and the traveling body 102.
- a control device 120 that controls the operation of each part of the hydraulic excavator 100 is provided in the operator's cab 118 .
- the work device 104 is a multi-joint type work device attached to the revolving body 103, and has a plurality of hydraulic actuators and a plurality of driven members driven by the plurality of hydraulic actuators.
- the work device 104 has a structure in which three driven members (a boom 111, an arm 112 and a bucket 113) are connected in series.
- the boom 111 is rotatably connected at its base end to the front portion of the revolving body 103 via a boom pin.
- the base end of the arm 112 is rotatably connected to the tip of the boom 111 via an arm pin.
- Bucket 113 is rotatably connected to the tip of arm 112 via a bucket pin.
- the boom 111 is rotationally driven by the telescopic motion of a boom cylinder 111A, which is a hydraulic actuator (hydraulic cylinder).
- the arm 112 is rotationally driven by an extension and contraction operation of an arm cylinder 112A, which is a hydraulic actuator (hydraulic cylinder).
- the bucket 113 is rotationally driven by the expansion and contraction of a bucket cylinder 113A, which is a hydraulic actuator (hydraulic cylinder).
- FIG. 2 is a diagram showing the hydraulic system 106 included in the hydraulic excavator 100 according to the first embodiment. Note that FIG. 2 shows a configuration for driving the swing motor 103A and the boom cylinder 111A, which are hydraulic actuators, and omits illustration of a configuration for driving other hydraulic actuators.
- the hydraulic system 106 includes a first hydraulic pump 13, a second hydraulic pump 27, a third hydraulic pump 29, and a swing motor 103A which is a hydraulic motor driven by hydraulic fluid as hydraulic fluid supplied from the first hydraulic pump 13. , a boom cylinder 111A that is extended and driven by hydraulic oil supplied from the low pressure accumulator 4 or the high pressure accumulator 21, a low pressure accumulator 4 that accumulates pressure oil discharged from the boom cylinder 111A, and pressure discharged from the swing motor 103A and a high-pressure accumulator 21 for accumulating oil.
- the direction control valve 14 which is a control valve for controlling the flow of hydraulic oil supplied from the first hydraulic pump 13 to the swing motor 103A, and the bottom side oil chamber 110a of the boom cylinder 111A have low pressure.
- a second boom control valve 19 which is a control valve for controlling the flow rate of hydraulic oil supplied from the high-pressure accumulator 21 to the bottom-side oil chamber 110a of the boom cylinder 111A when the pressure is high, is provided.
- the hydraulic system 106 includes a first pressure accumulation control valve 26, which is a control valve for controlling the flow of hydraulic oil supplied from the second hydraulic pump 27 to the low pressure accumulator 4, and a third hydraulic pump 29 to the high pressure accumulator 21.
- a second pressure accumulation control valve 28, which is a control valve for controlling the flow of the hydraulic oil that is applied, is provided between the swing motor 103A and the high-pressure accumulator 21, and is provided between the pressure on the swing motor 103A side and the pressure on the high-pressure accumulator 21 side. It is provided with a differential pressure control valve 130 that is a control valve that generates a front-to-rear differential pressure, and a tank 107 that stores hydraulic oil.
- the first hydraulic pump 13 , the second hydraulic pump 27 and the third hydraulic pump 29 are connected to the engine 32 .
- the first to third hydraulic pumps 13, 27, 29 are driven by the engine 32, suck up working oil from the tank 107, and discharge it as pressure oil.
- the first to third hydraulic pumps 13, 27, 29 are respectively variable displacement hydraulic pumps.
- the engine 32 is a power source of the hydraulic excavator 100, and is configured by an internal combustion engine such as a diesel engine, for example.
- the low-pressure accumulator 4 is a pressure accumulator that accumulates hydraulic oil discharged from the bottom side oil chamber 110a of the boom cylinder 111A and guided through the first boom control valve 2 when the boom cylinder 111A is contracted. That is, the low-pressure accumulator 4 accumulates pressure oil discharged from the boom cylinder 111A (hereinafter also referred to as return oil). The low pressure accumulator 4 supplies the stored pressure oil to the bottom side oil chamber 110a of the boom cylinder 111A through the first boom control valve 2 when the boom cylinder 111A is extended.
- the high-pressure accumulator 21 is a pressure accumulator that accumulates hydraulic oil having a pressure exceeding the swing brake pressure discharged from the swing motor 103A and guided through the differential pressure control valve 130 when the swing motor 103A is braked to the left or to the right. . That is, the high-pressure accumulator 21 accumulates pressure oil (hereinafter also referred to as return oil) discharged from the turning motor 103A.
- the high pressure accumulator 21 supplies the stored pressure oil to the bottom side oil chamber 110a of the boom cylinder 111A through the second boom control valve 19 when the boom cylinder 111A is extended.
- the set pressure (upper limit pressure) of the high pressure accumulator 21 is higher than the set pressure (upper limit pressure) of the low pressure accumulator 4 . This is because the swing brake pressure of the swing motor 103A is higher than the pressure of the bottom side oil chamber 110a of the boom cylinder 111A.
- the return oil from the hydraulic actuator is collected by the accumulator, it is preferable to collect it by the accumulator whose set pressure is close to the pressure of the return oil, because the pressure loss between the accumulator and the hydraulic actuator becomes smaller.
- the high-pressure accumulator 21 collects return oil from the swing motor 103A
- the low-pressure accumulator 4 collects return oil from the bottom-side oil chamber 110a of the boom cylinder 111A. Pressure loss can be kept low, and energy can be recovered efficiently.
- a communication path 161 communicates a bottom-side pipeline connected to the bottom-side oil chamber 110a of the boom cylinder 111A and a rod-side pipeline connected to the rod-side oil chamber 110b of the boom cylinder 111A.
- the communication passage 161 is provided with a communication control valve 7 that pressurizes the bottom-side oil chamber 110a and the rod-side oil chamber 110b by communicating the bottom-side oil chamber 110a and the rod-side oil chamber 110b of the boom cylinder 111A when the boom is lowered. is provided.
- a discharge passage which guides the hydraulic oil in the rod-side oil chamber 110b of the boom cylinder 111A to the tank 107, includes a discharge valve, which is a control valve that controls the flow of hydraulic oil discharged from the rod-side oil chamber 110b of the boom cylinder 111A to the tank 107.
- a control valve 3 is provided.
- a first branch passage 133a and a second branch passage 133b are connected to the first turning passage 131 and the second turning passage 132 connected to the turning motor 103A, respectively.
- the first branch passage 133a and the second branch passage 133b merge and are connected to a recovery passage 135 for guiding hydraulic fluid from the turning motor 103A to the high pressure accumulator 21.
- a check valve 23 that allows the hydraulic oil to flow only from the first turning passage 131 to the recovery passage 135 is provided in the first branch passage 133a.
- a check valve 24 that allows the hydraulic oil to flow only from the second turning passage 132 to the recovery passage 135 is provided in the second branch passage 133b.
- the check valves 23 and 24 send hydraulic fluid in the high-pressure side of the first turning passage 131 and the second turning passage 132 to the differential pressure control valve 130 .
- a recovery passage 135 connected to the high-pressure accumulator 21 is provided with a differential pressure control valve 130 that functions as a holding valve for holding the turning brake pressure.
- Differential pressure control valve 130, direction control valve 14, first pressure accumulation control valve 26, second pressure accumulation control valve 28, first boom control valve 2, second boom control valve 19, communication control valve 7, and discharge control valve 3 is controlled by a control signal (control current) output from the control device 120 .
- FIG. 3 is a hardware configuration diagram of the control device 120.
- the control device 120 includes a processor 151 such as a CPU (Central Processing Unit), an MPU (Micro Processing Unit), a DSP (Digital Signal Processor), and a volatile memory 152 called RAM (Random Access Memory). , a ROM (Read Only Memory), a flash memory, a non-volatile memory 153 such as a hard disk drive, an input interface 154, an output interface 155, and a computer equipped with other peripheral circuits.
- the control device 120 may be composed of one computer or may be composed of a plurality of computers.
- the non-volatile memory 153 stores programs capable of executing various calculations.
- the nonvolatile memory 153 is a storage medium that can read a program that implements the functions of this embodiment.
- the processor 151 is a processing device that expands a program stored in the nonvolatile memory 153 into the volatile memory 152 and executes operations, and is a processing device that receives signals from the input interface 154, the volatile memory 152, and the nonvolatile memory 153 according to the program. A predetermined arithmetic processing is performed on the .
- the input interface 154 converts signals input from each sensor (5b, 9, 18b, 30, 31) and the like into data that can be calculated by the processor 151.
- the output interface 155 generates an output signal according to the calculation result of the processor 151, and transmits the signal to each control valve (2, 3, 7, 14, 19, 26, 28, 130) and the engine 32. etc.
- the boom operating device 5 and the turning operating device 18 are connected to the control device 120 .
- the boom operation device 5 is an operation device that instructs the boom 111 to be raised and lowered according to the operator's operation.
- the boom operating device 5 has an operating lever (operating member) 5a that can be tilted, and an operating sensor 5b that outputs an operating signal to the control device 120 according to the amount of operation (operating angle) of the operating lever 5a.
- the turning operation device 18 is an operating device that instructs the turning body 103 to turn left and right according to the operation by the operator.
- the turning operation device 18 has an operation lever (operation member) 18a that can be tilted, and an operation sensor 18b that outputs an operation signal to the control device 120 according to the operation amount (operation angle) of the operation lever 18a.
- the bottom pressure sensor 9 , the first pressure sensor 30 and the second pressure sensor 31 are connected to the control device 120 .
- the bottom pressure sensor 9 is a pressure sensor that detects the pressure of hydraulic oil in the bottom side oil chamber 110a of the boom cylinder 111A and outputs the detection result to the control device 120.
- the first pressure sensor 30 is a pressure sensor that detects the pressure of hydraulic fluid in the low pressure accumulator 4 and outputs the detection result to the control device 120 .
- the second pressure sensor 31 is a pressure sensor that detects the pressure of hydraulic fluid in the high-pressure accumulator 21 and outputs the detection result to the control device 120 .
- the control device 120 determines whether the pressure detected by the first pressure sensor 30 is less than the low pressure lower limit side threshold. When the control device 120 determines that the pressure detected by the first pressure sensor 30 is less than the low-pressure lower limit threshold, the first pressure accumulation control valve 26 allows the second hydraulic pump 27 and the low-pressure accumulator 4 to communicate with each other. 2 Hydraulic oil discharged from the hydraulic pump 27 is accumulated in the low-pressure accumulator 4 . When the control device 120 determines that the pressure detected by the first pressure sensor 30 is equal to or higher than the low pressure upper limit threshold, the first pressure accumulation control valve 26 cuts off communication between the second hydraulic pump 27 and the low pressure accumulator 4 . .
- the low-pressure upper limit side threshold is set in advance to a value equal to or higher than the low-pressure lower limit side threshold.
- the low-voltage upper limit side threshold and the low-voltage lower limit side threshold are stored in the nonvolatile memory 153 .
- the control device 120 determines whether the pressure detected by the second pressure sensor 31 is less than the high pressure lower limit side threshold.
- the second pressure accumulation control valve 28 causes the third hydraulic pump 29 and the high pressure accumulator 21 to communicate with each other. 3 Hydraulic oil discharged from the hydraulic pump 29 is accumulated in the high-pressure accumulator 21 .
- the second pressure accumulation control valve 28 cuts off communication between the third hydraulic pump 29 and the high pressure accumulator 21 .
- the high-pressure upper limit threshold is set in advance to a value equal to or higher than the high-pressure lower limit threshold.
- the high voltage upper limit side threshold and the high voltage lower limit side threshold are stored in the nonvolatile memory 153 .
- the control device 120 operates the boom 111 by controlling the control valves (2, 3, 7, 19) based on the operation signal from the operation sensor 5b of the boom operation device 5 and the detection result of the bottom pressure sensor 9.
- the details of the control performed by the control device 120 to lower the boom 111 will be described below.
- the operation lever 5a of the boom operation device 5 When the operation lever 5a of the boom operation device 5 is operated in the downward direction, the operation sensor 5b outputs a boom-down operation signal to the control device 120.
- FIG. The control device 120 opens the communication control valve 7 to communicate the bottom-side oil chamber 110a and the rod-side oil chamber 110b of the boom cylinder 111A, thereby increasing the pressures of the bottom-side oil chamber 110a and the rod-side oil chamber 110b.
- the pressure Pbc of the bottom-side oil chamber 110a after the communication control valve 7 is opened is defined by Ab, the pressure-receiving area of the bottom-side oil chamber 110a, Ar, the pressure-receiving area of the rod-side oil chamber 110b, and the pressure Pbc of the communication control valve 7 before opening. Assuming that the pressure in the bottom side oil chamber 110a is Pb, it is expressed by the following equation.
- Pbc Ab/(Ab ⁇ Ar) ⁇ Pb Therefore, for example, if the pressure receiving area Ab of the bottom side oil chamber 110a is twice the pressure receiving area Ar of the rod side oil chamber 110b, the pressure of the bottom side oil chamber 110a after the communication control valve 7 opens is The pressure rises to twice the pressure in the bottom side oil chamber 110a before the valve 7 opens. Note that the control device 120 can adjust the degree of pressure increase of the bottom-side oil chamber 110 a by adjusting the opening degree of the communication control valve 7 .
- the control device 120 opens the first boom control valve 2 and accumulates the return oil from the bottom side oil chamber 110a of the boom cylinder 111A in the low pressure accumulator 4. Hydraulic oil in the bottom side oil chamber 110 a is guided through the communication control valve 7 to the rod side oil chamber 110 b and through the first boom control valve 2 to the low pressure accumulator 4 . As a result, the boom cylinder 111A contracts and the boom 111 rotates downward. As described above, the bottom-side oil chamber 110a and the rod-side oil chamber 110b are communicated with each other by the communication control valve 7, and the pressure of the bottom-side oil chamber 110a is increased. Therefore, the energy recovery efficiency of the low-pressure accumulator 4 is improved.
- the details of the control performed by the control device 120 to raise the boom 111 will be described below.
- the operation lever 5a of the boom operation device 5 When the operation lever 5a of the boom operation device 5 is operated in the raising direction, the operation sensor 5b outputs a boom raising operation signal to the control device 120.
- the control device 120 determines whether the pressure detected by the bottom pressure sensor 9 is less than the pressure threshold.
- the pressure threshold may be a predetermined constant, or may be a variable that increases as the pressure detected by the first pressure sensor 30 increases.
- the control device 120 determines that the pressure detected by the bottom pressure sensor 9 is less than the pressure threshold value, that is, when the bottom side oil chamber 110a is in a low pressure state, the first boom control valve 2 and the discharge control valve Open 3.
- the low-pressure accumulator 4 is supplied to the bottom side oil chamber 110a, and hydraulic oil is discharged from the rod side oil chamber 110b to the tank 107.
- the boom cylinder 111A extends and the boom 111 rotates upward.
- the second boom control valve 19 and the discharge control valve Open 3.
- pressure oil discharged from the high-pressure accumulator 21 is supplied to the bottom-side oil chamber 110a, and hydraulic oil is discharged from the rod-side oil chamber 110b to the tank 107.
- the boom cylinder 111A extends and the boom 111 rotates upward.
- the control device 120 drives the boom cylinder 111A by the low pressure accumulator 4 when the bottom side oil chamber 110a is in a low pressure state, and drives the boom cylinder 111A by the high pressure accumulator 21 when the bottom side oil chamber 110a is in a high pressure state. It drives the boom cylinder 111A.
- the pressure loss between the boom cylinder 111A and the accumulator that drives the boom cylinder 111A can be reduced. Therefore, according to this embodiment, the boom cylinder 111A can be efficiently driven.
- the pressure of the low-pressure accumulator 4 is kept constant by supplying hydraulic fluid from the second hydraulic pump 27, and the pressure of the high-pressure accumulator 21 is kept constant by supplying hydraulic fluid from the third hydraulic pump 29. kept in Therefore, the boom cylinder 111A can be driven to extend by opening the first boom control valve 2 or the second boom control valve 19 at arbitrary timing.
- the control device 120 operates the revolving body 103 by controlling the direction control valve 14 based on the operation signal from the operation sensor 18b of the revolving operation device 18.
- control device 120 determines whether the operation lever 18a has been turned left or right.
- the control device 120 determines that the operation lever 18a has been turned to the left, the control device 120 outputs a control current corresponding to the amount of operation of the operation lever 18a to the first solenoid of the direction control valve 14, and rotates the spool of the direction control valve 14 to the first solenoid. Drive in one direction D1.
- hydraulic fluid discharged from the first hydraulic pump 13 is supplied to the swing motor 103A through the direction control valve 14 and the first swing passage 131, and the swing motor 103A rotates in the forward direction.
- Return oil from the swing motor 103A is discharged to the tank 107 through the second swing passage 132 and the directional control valve 14 .
- the revolving body 103 revolves leftward.
- the control device 120 determines that the operation lever 18a has been turned to the right, the control device 120 outputs a control current corresponding to the amount of operation of the operation lever 18a to the second solenoid of the direction control valve 14 to turn the spool of the direction control valve 14. It drives in a second direction D2 opposite to the first direction D1.
- hydraulic fluid discharged from the first hydraulic pump 13 is supplied to the swing motor 103A through the direction control valve 14 and the second swing passage 132, and the swing motor 103A rotates in the direction opposite to the forward direction.
- Return oil from the swing motor 103A is discharged to the tank 107 through the second swing passage 132 and the directional control valve 14 .
- the revolving body 103 revolves rightward.
- the spool of the directional control valve 14 When the operating lever 18a is returned to the neutral position while the revolving body 103 is revolving, the spool of the directional control valve 14 returns to the neutral position. When the spool of directional control valve 14 returns to the neutral position, the actuator port of directional control valve 14 is closed. That is, the supply of hydraulic oil to the swing motor 103A through the direction control valve 14 and the discharge of hydraulic oil from the swing motor 103A through the direction control valve 14 are blocked.
- the pressure in the passage through which hydraulic oil is discharged from the turning motor 103A rises.
- a braking force that reduces the swing speed of the swing body 103 acts on the swing motor 103A. That is, the pressure in the high pressure side passage acts on the turning motor 103A as brake pressure.
- the pressure in the high pressure side passage exceeds the set differential pressure of the differential pressure control valve 130, hydraulic fluid is introduced from the high pressure side passage through the differential pressure control valve 130 to the high pressure accumulator 21, and the high pressure accumulator 21 accumulates pressure. Therefore, in the hydraulic system 106 of this embodiment, the return oil from the turning motor 103A can be sent to the high-pressure accumulator 21 to recover the energy while ensuring the required braking force.
- the differential pressure control valve 130 determines that the difference between the back pressure of the swing motor 103A, which is the pressure on the upstream side of itself, and the pressure of the high-pressure accumulator 21, which is the pressure on the downstream side of the differential pressure control valve 130, is the set differential pressure. Below, the valve is closed, and when the set differential pressure is exceeded, the valve is opened.
- the differential pressure control valve 130 is an electromagnetic proportional pressure control valve that can change the set differential pressure according to the control current output by the control device 120 and supplied to the solenoid 130a.
- the set differential pressure of differential pressure control valve 130 is adjusted according to the control current output from control device 120 .
- the control device 120 controls the differential pressure control valve 130 based on the detection result of the second pressure sensor 31 .
- the differential pressure control valve 130 has the same configuration as a well-known electromagnetic proportional relief valve. and a spring provided in the .
- a spring biases the poppet toward the valve seat.
- FIG. 4 is a block diagram showing control of the differential pressure control valve 130 by the control device 120 according to the first embodiment. As shown in FIG. 4 , the control device 120 functions as a differential pressure calculator 121 and an output converter 122 by executing programs stored in the nonvolatile memory 153 .
- the differential pressure calculation unit 121 refers to the differential pressure characteristic Cp stored in advance in the nonvolatile memory 153, and sets the differential pressure control valve 130 based on the pressure of the high pressure accumulator 21 detected by the second pressure sensor 31. Calculate the differential pressure ⁇ P.
- the differential pressure characteristic Cp is a characteristic in which the set differential pressure ⁇ P of the differential pressure control valve 130 decreases as the pressure of the high pressure accumulator 21 increases, and is stored in the nonvolatile memory 153 in the form of a table, for example.
- the differential pressure characteristic Cp is determined in advance so that the brake pressure of the swing motor 103A, which is the pressure on the upstream side of the differential pressure control valve 130, is kept constant even when the pressure of the high-pressure accumulator 21 changes. .
- the differential pressure is 10 MPa. If the pressure of the high pressure accumulator 21 is 21 MPa, the differential pressure will be 9 MPa.
- the output conversion unit 122 refers to the control current characteristic Ci pre-stored in the nonvolatile memory 153, and based on the set differential pressure ⁇ P calculated by the differential pressure calculation unit 121, the solenoid 130a of the differential pressure control valve 130 A control current value Ic to be supplied is calculated.
- the output converter 122 outputs a control current corresponding to the calculation result to the solenoid 130 a of the differential pressure control valve 130 .
- the control current characteristic Ci is a characteristic in which the control current value Ic increases as the set differential pressure ⁇ P increases.
- the main operations of the hydraulic excavator 100 according to the first embodiment will be described.
- the operator operates the operation lever 18a of the turning operation device 18 shown in FIG.
- the spool of the directional control valve 14 returns to the neutral position.
- the supply of hydraulic oil to the swing motor 103A through the directional control valve 14 and the first turning passage 131 is cut off, and the discharge of hydraulic oil through the second turning passage 132 and the directional control valve 14 is cut off.
- the pressure in the second turning passage 132 increases.
- the differential pressure control valve 130 opens.
- the hydraulic fluid in the second turning passage 132 passes through the check valve 24 in the second branch passage 133b and the differential pressure control valve 130 in the recovery passage 135, and is led to the high pressure accumulator 21.
- the differential pressure control valve 130 operates so that the differential pressure across it is maintained at the set differential pressure ⁇ P.
- the set differential pressure ⁇ P is determined by the solenoid thrust generated according to the spring force and the control current.
- the set differential pressure ⁇ P of the differential pressure control valve 130 becomes smaller as the pressure of the high pressure accumulator 21 increases.
- the back pressure of the turning motor 103A that is, the change in brake pressure can be reduced. That is, according to this embodiment, even when the pressure of the high-pressure accumulator 21 changes, the braking force of the turning motor 103A can be stably generated, so the decelerating operation of the turning body 103 is stabilized. As a result, in this embodiment, the operability desired by the operator can be realized.
- the hydraulic excavator (work machine) 100 is operated by an engine 32, a first hydraulic pump (hydraulic pump) 13 driven by the engine 32 and discharging pressure oil, and the pressure oil discharged by the first hydraulic pump 13.
- a swing motor (hydraulic actuator) 103A a high-pressure accumulator (pressure accumulator) 21 for accumulating pressure oil discharged from the swing motor 103A, a pressure accumulator 21 provided between the swing motor 103A and the high-pressure accumulator 21, and a pressure of the swing motor 103A and the pressure of the high-pressure accumulator 21, a second pressure sensor (pressure sensor) 31 that detects the pressure of the high-pressure accumulator 21, and the detection result of the second pressure sensor 31.
- the control device 120 controls the differential pressure control valve 130 so that the differential pressure across the front and rear of the accumulator 21 decreases as the pressure of the high-pressure accumulator 21 detected by the second pressure sensor 31 increases.
- the differential pressure across the differential pressure control valve 130 is reduced as the pressure of the high-pressure accumulator 21 rises, thereby suppressing changes in the brake pressure, which is the pressure on the downstream side of the swing motor 103A. That is, with the above configuration, a stable braking force can be generated. Therefore, according to the present embodiment, it is possible to provide the hydraulic excavator 100 that can stably operate the swing motor 103A when the pressure oil discharged from the swing motor 103A is accumulated in the high-pressure accumulator 21 .
- the differential pressure control valve 130 is composed of an electromagnetic proportional valve whose set differential pressure ⁇ P is adjusted according to the control current output by the control device 120 .
- the differential pressure control valve 130 closes when the set differential pressure ⁇ P or less, and opens when the set differential pressure ⁇ P is exceeded.
- the control device 120 reduces the set differential pressure ⁇ P of the differential pressure control valve 130 according to the increase in the pressure of the high pressure accumulator 21 detected by the second pressure sensor 31 . In this configuration, when the difference between the pressure of the high-pressure accumulator 21 and the brake pressure, which is the pressure on the downstream side of the swing motor 103A, exceeds the set differential pressure ⁇ P, the differential pressure control valve 130 opens and the brake pressure rises. suppressed.
- FIG. 5 A hydraulic excavator 200 according to the second embodiment will be described with reference to FIGS. 5 and 6.
- FIG. The same reference numerals are given to the same or corresponding configurations as those described in the first embodiment, and the differences will be mainly described.
- the revolving body 103 of the hydraulic excavator 200 according to the second embodiment is equipped with an angular velocity sensor 33 such as a gyroscope that detects the angular velocity of revolving of the revolving body 103 .
- Angular velocity sensor 33 is connected to control device 220 and outputs detection results to control device 220 .
- the control device 220 according to the second embodiment operates the differential pressure control valve 230 so that the opening area of the differential pressure control valve 230 increases as the pressure of the high-pressure accumulator 21 detected by the second pressure sensor 31 increases. Control. Further, the control device 220 controls the differential pressure control valve 230 so that the opening area of the differential pressure control valve 230 increases as the turning angular velocity detected by the angular velocity sensor 33 increases.
- FIG. 5 is similar to FIG. 2 and shows the hydraulic system 206 included in the hydraulic excavator 200 according to the second embodiment.
- a differential pressure control valve 230 which is a spool type electromagnetic proportional valve, is provided in place of the differential pressure control valve 130 described in the first embodiment.
- the differential pressure control valve 230 has a spool 230b that is a valve element and a sleeve 230c that is a holding member that holds the spool 230b.
- the differential pressure control valve 230 opens the recovery passage 135 by causing the spool 230b to slide within the sleeve 230c according to the control current output by the control device 220 and supplied to the solenoid 230a.
- the control device 220 adjusts the opening area of the differential pressure control valve 230, i. Adjust the cross-sectional area of the road.
- the control device 220 adjusts the differential pressure across the differential pressure control valve 230 by making the opening of the differential pressure control valve 230 function as an orifice and adjusting the opening area.
- the control device 220 generates a desired brake pressure by controlling the opening area of the differential pressure control valve 230 based on the orifice equation from the flow rate of hydraulic oil discharged from the swing motor 103A and the pressure of the high-pressure accumulator 21.
- the orifice formula generally expresses the relationship between the differential pressure before and after the restrictor, the flow rate, and the aperture area of the restrictor. If unit conversion is omitted, it can be expressed as the following formula (1).
- Q is the flow rate flowing through the restriction
- A is the opening area of the restriction
- P1 is the upstream pressure of the orifice
- P2 is the downstream pressure of the orifice
- C is the flow coefficient
- Q is the flow rate of hydraulic oil discharged from the swing motor 103A
- A is the opening area of the differential pressure control valve 230
- P1 is the upstream pressure of the differential pressure control valve 230
- P2 is the differential pressure control valve 230.
- FIG. 6 is a block diagram showing control of the differential pressure control valve 230 by the control device 220 according to the second embodiment.
- the control device 220 executes the program stored in the nonvolatile memory 153 to obtain the first gain multiplier 223 , the subtractor 225 , the square rooter 226 , the second gain multiplier 227 . , a division unit 228 and an output conversion unit 229 .
- the subtraction unit 225 calculates, for example, the high pressure detected by the second pressure sensor 31 from the predetermined target turning brake pressure stored in the nonvolatile memory 153 (that is, the target value of the upstream pressure P1 of the differential pressure control valve 230).
- the pressure of the accumulator 21 (that is, the measured value of the downstream pressure P2 of the differential pressure control valve 230) is subtracted to calculate the target differential pressure (P1-P2).
- the square root unit 226 calculates the square root of the target differential pressure (P1-P2) calculated by the subtraction unit 225.
- a second gain multiplier 227 multiplies the calculation result of the square rooter 226 by a predetermined gain K2.
- the gain K2 corresponds to the flow coefficient C in equation (2).
- the division unit 228 divides the calculation result of the first gain multiplication unit 223 by the calculation result of the second gain multiplication unit 227 to obtain the target opening area (also referred to as the target opening area) A of the differential pressure control valve 230. Calculate.
- the output conversion unit 229 refers to the control current characteristic Ci2 pre-stored in the nonvolatile memory 153, and supplies it to the solenoid 230a of the differential pressure control valve 230 based on the target opening area A calculated by the division unit 228.
- a control current value Ic is calculated.
- the output converter 229 outputs a control current corresponding to the calculation result to the solenoid 230 a of the differential pressure control valve 230 .
- the control current characteristic Ci2 is a characteristic in which the control current value Ic increases as the target opening area A increases.
- the differential pressure control valve 230 is configured by an electromagnetic proportional valve whose opening area is adjusted according to the control current output by the control device 220.
- the control device 220 controls the differential pressure control valve 230 so that the opening area of the differential pressure control valve 230 increases as the pressure of the high pressure accumulator 21 detected by the second pressure sensor 31 increases. Further, the control device 220 controls the differential pressure control valve 230 so that the opening area of the differential pressure control valve 230 increases as the angular velocity of the revolving body 103 detected by the angular velocity sensor 33 increases.
- the opening area of the differential pressure control valve 230 increases as the pressure of the high pressure accumulator 21 increases, so that the increase in brake pressure caused by the pressure increase in the high pressure accumulator 21 is suppressed. Also, changes in brake pressure due to changes in the flow rate of the turning motor 103A are suppressed. Therefore, according to the second embodiment, when pressurized oil discharged from the swing motor 103A is accumulated in the high-pressure accumulator 21, the swing motor 103A can be stably operated.
- the control devices 120 and 220 operate the differential pressure control valves 130 and 230 provided between the high-pressure accumulator 21 that accumulates the return oil of the swing motor 103A that swings the swing body 103 and the swing motor 103A.
- the control devices 120, 220 control the opening area of the first boom control valve 2 provided between the low-pressure accumulator 4 that accumulates the return oil of the boom cylinder 111A and the boom cylinder 111A, thereby controlling the opening area of the first boom control valve. 2 may be adjusted.
- FIG. 7 is similar to FIG. 2 and shows a hydraulic system 306 included in a hydraulic excavator 300 according to Modification 1. As shown in FIG.
- the boom cylinder 111A of the hydraulic excavator 300 according to Modification 1 is provided with a stroke sensor 34 that detects the stroke of the boom cylinder 111A.
- the control device 320 calculates the extension/retraction speed of the boom cylinder 111A (hereinafter also referred to as cylinder speed) based on the detection result of the stroke sensor 34 .
- the first boom control valve 2 is a spool type valve whose opening area can be changed according to the control current output by the control device 320 and supplied to the solenoid 2a. It is an electromagnetic proportional valve.
- the control device 320 opens the first boom control valve 2 and accumulates the return oil from the bottom side oil chamber 110a of the boom cylinder 111A in the low pressure accumulator 4. At this time, the control device 320 adjusts the control current supplied to the solenoid 2a of the first boom control valve 2 to change the opening area of the first boom control valve 2, that is, from the boom cylinder 111A toward the low pressure accumulator 4. Adjust the cross-sectional area of the flow path of the hydraulic fluid. The control device 320 adjusts the differential pressure across the first boom control valve 2 by making the opening of the first boom control valve 2 function as an orifice and adjusting the opening area.
- FIG. 8 is a block diagram showing control of the first boom control valve 2 by the control device 320 according to the third embodiment.
- the control device 320 is configured by executing a program stored in the nonvolatile memory 153 so as to implement a speed calculation section 322, a first gain multiplication section 323, a subtraction section 325, a square root section 326, a first gain multiplication section 323, a It functions as a 2-gain multiplier 327 , a divider 328 and an output converter 329 .
- the speed calculation unit 322 calculates the cylinder speed Vs based on the change over time of the stroke of the boom cylinder 111A detected by the stroke sensor 34.
- the subtraction unit 325 subtracts the low pressure detected by the first pressure sensor 30 from the target bottom pressure (i.e., the target value of the upstream pressure P1 of the first boom control valve 2) stored in the nonvolatile memory 153 in advance.
- the pressure of the accumulator 4 (that is, the measured value of the downstream side pressure P2 of the first boom control valve 2) is subtracted to calculate the target front-to-rear differential pressure (P1-P2).
- the square root unit 326 calculates the square root of the target front-rear differential pressure (P1-P2) calculated by the subtraction unit 325.
- a second gain multiplier 327 multiplies the calculation result of the square rooter 326 by a predetermined gain Kb.
- the gain Kb corresponds to the flow coefficient C in Equation (2).
- the division unit 328 divides the calculation result of the first gain multiplication unit 323 by the calculation result of the second gain multiplication unit 327 to obtain the target opening area (also referred to as the target opening area) A2 of the first boom control valve 2. to calculate
- the output conversion unit 329 refers to the control current characteristic Ci3 pre-stored in the nonvolatile memory 153, and based on the target opening area A2 calculated by the division unit 328, supplies the current to the solenoid 2a of the first boom control valve 2. A control current value Ic to be used is calculated. The output converter 329 outputs a control current corresponding to the calculation result to the solenoid 2a of the first boom control valve 2.
- FIG. The control current characteristic Ci3 is a characteristic in which the control current value Ic increases as the target opening area A2 increases.
- the first boom control valve 2 functions as a differential pressure control valve that generates a front-rear differential pressure when the boom cylinder 111A is lowered.
- the first boom control valve 2 is a control valve whose opening area can be changed according to the control current supplied to the solenoid 2a.
- Control device 320 calculates the cylinder speed based on the stroke of boom cylinder 111A detected by stroke sensor 34 .
- the control device 320 controls the first boom control valve 2 so that the opening area of the first boom control valve 2 increases as the pressure of the low pressure accumulator 4 detected by the first pressure sensor 30 increases. Further, the control device 320 controls the first boom control valve 2 such that the opening area of the first boom control valve 2 increases as the cylinder speed increases.
- the opening area of the first boom control valve 2 increases as the pressure of the low-pressure accumulator 4 rises, so the bottom pressure rise of the boom cylinder 111A caused by the pressure rise of the low-pressure accumulator 4 is suppressed.
- the boom cylinder 111A can be stably operated.
- the hydraulic excavator 300 may perform crane work in which a wire is hung on a hook provided on the back of the bucket 113 to lift a load. In the crane operation, the lifting operation and lowering operation of the boom 111 move the suspended load in the vertical direction.
- the boom cylinder 111A contracts and the boom 111 rotates downward.
- Return oil from the bottom side oil chamber 110a of the boom cylinder 111A is led to the low pressure accumulator 4 through the first boom control valve 2.
- the control device 320 controls the first boom control valve (differential pressure control valve) 2 in response to an increase in the pressure of the low pressure accumulator (pressure accumulator) 4 detected by the first pressure sensor (pressure sensor) 30 .
- the first boom control valve 2 is controlled so that the opening area of is increased.
- the differential pressure across the first boom control valve 2 decreases as the pressure in the low pressure accumulator 4 increases. Therefore, while the pressure of the low-pressure accumulator 4 is rising, the pressure of the bottom side oil chamber 110a of the boom cylinder 111A is kept constant, and the speed change of the boom cylinder 111A is suppressed. Since the boom cylinder 111A operates stably, it is possible to prevent the suspended load from swinging during crane work. Therefore, according to Modification 1, the efficiency of crane work can be improved.
- the working machine is the crawler hydraulic excavator 100, 200, 300, but the present invention is not limited to this.
- the present invention can be applied to various working machines such as wheel-type hydraulic excavators and wheel loaders.
- Output conversion unit 130 Differential pressure control valve 130a Solenoid 151 Processor 152 Volatile memory 153 Nonvolatile memory 200 Hydraulic excavator (working machine) 206 Hydraulic system 220 Control device 223 First gain multiplication unit 225 Subtraction unit 226 Square root unit 227 Second gain multiplication unit 228 Division unit 229 Output conversion unit 230 Differential pressure control valve 230a Solenoid 230b Spool 230c Sleeve 300 Hydraulic excavator (working machine) 306 Hydraulic system 320 Control device 322 Speed calculation unit 323 First gain multiplication unit 325 Subtraction unit 326 Square root unit 327 ... second gain multiplication section, 328 ... division section, 329 ... output conversion section
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Abstract
Description
図1は、第1実施形態に係る油圧ショベル100の側面図である。図1に示すように、油圧ショベル100は、機体105と、機体105に取り付けられた作業装置104と、を備える。機体105は、クローラ式の走行体102と、走行体102上に旋回可能に設けられた旋回体103と、を有する。走行体102は、左右一対のクローラを走行モータ102Aによって駆動することにより走行する。旋回体103は、旋回モータ103Aを有する旋回装置を介して走行体102に連結され、旋回モータ103Aによって駆動されて走行体102に対して旋回する。
Pbc=Ab/(Ab-Ar)×Pb
したがって、例えば、ボトム側油室110aの受圧面積Abがロッド側油室110bの受圧面積Arの2倍であれば、連通制御弁7が開いた後のボトム側油室110aの圧力は、連通制御弁7が開く前のボトム側油室110aの圧力の2倍まで上昇する。なお、制御装置120は、連通制御弁7の開度を調整することにより、ボトム側油室110aの昇圧の度合いを調整することができる。
図5及び図6を参照して、第2実施形態に係る油圧ショベル200について説明する。なお、第1実施形態で説明した構成と同一もしくは相当する構成には同一の参照番号を付し、相違点を主に説明する。
上記実施形態では、制御装置120,220が、旋回体103を旋回させる旋回モータ103Aの戻り油を蓄圧する高圧アキュムレータ21と、旋回モータ103Aとの間に設けられた差圧制御弁130,230の前後差圧を調整する例について説明したが、本発明はこれに限定されない。制御装置120,220は、ブームシリンダ111Aの戻り油を蓄圧する低圧アキュムレータ4と、ブームシリンダ111Aとの間に設けられた第1ブーム制御弁2の開口面積を制御して、第1ブーム制御弁2の前後差圧を調整するようにしてもよい。
上記実施形態では、作業機械がクローラ式の油圧ショベル100,200,300である場合を例に説明したが、本発明はこれに限定されない。ホイール式の油圧ショベル、ホイールローダ等の種々の作業機械に本発明を適用することができる。
Claims (4)
- エンジンと、
前記エンジンにより駆動され圧油を吐出する油圧ポンプと、
前記油圧ポンプにより吐出される圧油により動作する油圧アクチュエータと、
前記油圧アクチュエータから排出される圧油を蓄圧する蓄圧装置と、
前記油圧アクチュエータと前記蓄圧装置との間に設けられ、前記油圧アクチュエータの圧力と前記蓄圧装置の圧力との前後差圧を発生させる差圧制御弁と、
前記蓄圧装置の圧力を検出する圧力センサと、
前記圧力センサの検出結果に基づいて前記差圧制御弁を制御する制御装置と、を備えた作業機械において、
前記制御装置は、前記圧力センサにより検出される前記蓄圧装置の圧力の上昇に応じて前記前後差圧が低減するように、前記差圧制御弁を制御する
ことを特徴とする作業機械。 - 請求項1に記載の作業機械において、
前記差圧制御弁は、前記制御装置により出力される制御電流に応じて設定差圧が調整される電磁比例弁により構成され、前記設定差圧以下では閉弁し、前記設定差圧を超えると開弁し、
前記制御装置は、前記圧力センサにより検出される前記蓄圧装置の圧力の上昇に応じて前記差圧制御弁の前記設定差圧を低減する
ことを特徴とする作業機械。 - 請求項1に記載の作業機械において、
前記差圧制御弁は、前記制御装置により出力される制御電流に応じて開口面積が調整される電磁比例弁により構成され、
前記制御装置は、前記圧力センサにより検出される前記蓄圧装置の圧力の上昇に応じて前記差圧制御弁の開口面積が大きくなるように、前記差圧制御弁を制御する
ことを特徴とする作業機械。 - 請求項1に記載の作業機械において、
走行体と、
前記走行体に旋回可能に設けられた旋回体と、
前記旋回体の旋回の角速度を検出する角速度センサと、をさらに備え、
前記油圧アクチュエータは、前記旋回体を旋回させる旋回モータであり、
前記制御装置は、前記角速度センサにより検出される角速度が大きいほど前記差圧制御弁の開口面積が大きくなるように、前記差圧制御弁を制御する
ことを特徴とする作業機械。
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EP22774595.7A EP4261352A1 (en) | 2021-03-24 | 2022-01-19 | Work machine |
US18/272,121 US20240068203A1 (en) | 2021-03-24 | 2022-01-19 | Work Machine |
KR1020237023384A KR20230117219A (ko) | 2021-03-24 | 2022-01-19 | 작업 기계 |
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WO2016056442A1 (ja) * | 2014-10-06 | 2016-04-14 | 住友重機械工業株式会社 | ショベル |
JP2016205492A (ja) | 2015-04-21 | 2016-12-08 | キャタピラー エス エー アール エル | 流体圧回路および作業機械 |
JP2017119974A (ja) * | 2015-12-28 | 2017-07-06 | 住友重機械工業株式会社 | ショベル |
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JP5419572B2 (ja) | 2009-07-10 | 2014-02-19 | カヤバ工業株式会社 | ハイブリッド建設機械の制御装置 |
US20140208728A1 (en) * | 2013-01-28 | 2014-07-31 | Caterpillar Inc. | Method and Hydraulic Control System Having Swing Motor Energy Recovery |
US9290911B2 (en) * | 2013-02-19 | 2016-03-22 | Caterpillar Inc. | Energy recovery system for hydraulic machine |
US20150247509A1 (en) * | 2014-02-28 | 2015-09-03 | Caterpillar Inc. | Machine having hydraulic start assist system |
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JP6636977B2 (ja) | 2017-03-14 | 2020-01-29 | 日立建機株式会社 | 作業機械の油圧駆動装置 |
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