WO2022137872A1 - 作業機械 - Google Patents
作業機械 Download PDFInfo
- Publication number
- WO2022137872A1 WO2022137872A1 PCT/JP2021/041600 JP2021041600W WO2022137872A1 WO 2022137872 A1 WO2022137872 A1 WO 2022137872A1 JP 2021041600 W JP2021041600 W JP 2021041600W WO 2022137872 A1 WO2022137872 A1 WO 2022137872A1
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- WO
- WIPO (PCT)
- Prior art keywords
- valve
- opening area
- operation amount
- pressure
- pilot
- Prior art date
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- 239000010720 hydraulic oil Substances 0.000 claims abstract description 81
- 230000007935 neutral effect Effects 0.000 claims description 23
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- 238000009434 installation Methods 0.000 description 1
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- 230000002265 prevention Effects 0.000 description 1
- 238000011144 upstream manufacturing Methods 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
- E02F9/2278—Hydraulic circuits
- E02F9/2296—Systems with a variable displacement pump
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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
- E02F9/2203—Arrangements for controlling the attitude of actuators, e.g. speed, floating function
- E02F9/2207—Arrangements for controlling the attitude of actuators, e.g. speed, floating function for reducing or compensating oscillations
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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
- E02F9/2278—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
- E02F9/2285—Pilot-operated systems
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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
- F15B20/00—Safety arrangements for fluid actuator systems; Applications of safety devices in fluid actuator systems; Emergency measures for fluid actuator systems
- F15B20/007—Overload
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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
- F15B21/04—Special measures taken in connection with the properties of the fluid
- F15B21/045—Compensating for variations in viscosity or temperature
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- E—FIXED CONSTRUCTIONS
- E02—HYDRAULIC ENGINEERING; FOUNDATIONS; SOIL SHIFTING
- E02F—DREDGING; SOIL-SHIFTING
- E02F3/00—Dredgers; Soil-shifting machines
- E02F3/04—Dredgers; Soil-shifting machines mechanically-driven
- E02F3/28—Dredgers; Soil-shifting machines mechanically-driven with digging tools mounted on a dipper- or bucket-arm, i.e. there is either one arm or a pair of arms, e.g. dippers, buckets
- E02F3/36—Component parts
- E02F3/42—Drives for dippers, buckets, dipper-arms or bucket-arms
- E02F3/43—Control of dipper or bucket position; Control of sequence of drive operations
- E02F3/435—Control of dipper or bucket position; Control of sequence of drive operations for dipper-arms, backhoes or the like
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
- F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
- F15B11/00—Servomotor systems without provision for follow-up action; Circuits therefor
- F15B11/16—Servomotor systems without provision for follow-up action; Circuits therefor with two or more servomotors
- F15B11/161—Servomotor systems without provision for follow-up action; Circuits therefor with two or more servomotors with sensing of servomotor demand or load
- F15B11/165—Servomotor systems without provision for follow-up action; Circuits therefor with two or more servomotors with sensing of servomotor demand or load for adjusting the pump output or bypass in response to demand
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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
- F15B13/04—Fluid distribution or supply devices characterised by their adaptation to the control of servomotors for use with a single servomotor
- F15B13/042—Fluid distribution or supply devices characterised by their adaptation to the control of servomotors for use with a single servomotor operated by fluid pressure
- F15B13/0422—Fluid distribution or supply devices characterised by their adaptation to the control of servomotors for use with a single servomotor operated by fluid pressure with manually-operated pilot valves, e.g. joysticks
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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
- F15B13/04—Fluid distribution or supply devices characterised by their adaptation to the control of servomotors for use with a single servomotor
- F15B13/042—Fluid distribution or supply devices characterised by their adaptation to the control of servomotors for use with a single servomotor operated by fluid pressure
- F15B13/043—Fluid distribution or supply devices characterised by their adaptation to the control of servomotors for use with a single servomotor operated by fluid pressure with electrically-controlled pilot 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
- F15B21/00—Common features of fluid actuator systems; Fluid-pressure actuator systems or details thereof, not covered by any other group of this subclass
- F15B21/08—Servomotor systems incorporating electrically operated control means
- F15B21/087—Control strategy, e.g. with block diagram
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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
- F15B2211/20584—Combinations of pumps with high and low 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
- F15B2211/30—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
- F15B2211/31—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
- F15B2211/32—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
- F15B2211/30—Directional control
- F15B2211/35—Directional control combined with flow control
- F15B2211/351—Flow control by regulating means in feed line, i.e. meter-in control
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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
- F15B2211/35—Directional control combined with flow control
- F15B2211/353—Flow control by regulating means in return line, i.e. meter-out control
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
- F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
- F15B2211/00—Circuits for servomotor systems
- F15B2211/40—Flow control
- F15B2211/415—Flow control characterised by the connections of the flow control means in the circuit
- F15B2211/41554—Flow control characterised by the connections of the flow control means in the circuit being connected to a return line and a directional control valve
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
- F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
- F15B2211/00—Circuits for servomotor systems
- F15B2211/40—Flow control
- F15B2211/42—Flow control characterised by the type of actuation
- F15B2211/426—Flow 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
- F15B2211/40—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
- F15B2211/60—Circuit components or control therefor
- F15B2211/63—Electronic controllers
- F15B2211/6303—Electronic controllers using input signals
- F15B2211/6306—Electronic controllers using input signals representing a pressure
- F15B2211/6316—Electronic controllers using input signals representing a pressure the pressure being a pilot 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
- F15B2211/60—Circuit components or control therefor
- F15B2211/63—Electronic controllers
- F15B2211/6303—Electronic controllers using input signals
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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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- 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
- F15B2211/60—Circuit components or control therefor
- F15B2211/635—Circuits providing pilot pressure to pilot pressure-controlled fluid circuit elements
- F15B2211/6355—Circuits providing pilot pressure to pilot pressure-controlled fluid circuit elements having valve means
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
- F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
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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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- 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
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- 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
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- 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
- F15B2211/86—Control during or prevention of abnormal conditions
- F15B2211/8606—Control during or prevention of abnormal conditions the abnormal condition being a shock
Definitions
- the present invention relates to a work machine.
- the hydraulic system of the work machine described in Patent Document 1 includes a center bypass cut valve arranged on the downstream side of a control valve corresponding to a specific hydraulic cylinder in a center bypass line, and a cylinder chamber on the load holding side of the specific hydraulic cylinder.
- the center bypass cut valve is operated when the operating means is operated to supply hydraulic oil to the hydraulic pump, and the control means for controlling the discharge pressure of the hydraulic pump to be higher than the load pressure of a specific hydraulic cylinder is provided. ing.
- Patent Document 2 in a hydraulic circuit that directly drives and controls the ascent and descent of a boom cylinder, as an oil shock generation prevention device, an oil chamber on the bottom side and an oil chamber on the rod side of the load cylinder are provided via an electromagnetic on-off valve and a throttle valve.
- a lifting hydraulic circuit provided with a communicating bypass circuit is disclosed.
- the control unit transmits a command to open the bypass circuit for a predetermined time to the electromagnetic on-off valve.
- Patent Document 2 aims to reduce the generation of surge pressure, but when the operation of the electromagnetic on-off valve provided in the bypass circuit is delayed as compared with the operation of the hydraulic pilot 3-position switching valve. , It may not be possible to prevent the occurrence of surge pressure.
- An object of the present invention is to prevent the generation of surge pressure when the hydraulic actuator is stopped.
- the work machine includes a pump that discharges the hydraulic oil sucked from the tank, a hydraulic actuator driven by the hydraulic oil discharged from the pump, and the hydraulic oil from the pump in a neutral position.
- a flow control valve that has a center bypass passage portion that leads to the hydraulic actuator and controls the flow rate of the hydraulic oil supplied to the hydraulic actuator according to the amount of displacement from the neutral position, and the hydraulic oil supplied from the pump are described above.
- An electromagnetic proportional valve that generates a pilot pressure to control the bypass cut valve, an operating device for operating the hydraulic actuator, and a pilot pressure that controls the flow rate control valve based on the operating amount of the operating device. It includes a pilot valve to be generated, an operation amount detection device for detecting the operation amount of the operation device, and a control device for controlling the electromagnetic proportional valve based on the operation amount detected by the operation amount detection device.
- the control device when the operation amount detected by the operation amount detection device is in the range of the minimum operation amount or more and less than the predetermined operation amount, the opening area of the bypass cut valve becomes the minimum opening area according to the increase in the operation amount.
- the electromagnetic proportional valve is controlled so as to be as small as possible, and when the operation amount detected by the operation amount detection device is the maximum operation amount, the opening area of the bypass cut valve is larger than the minimum opening area.
- the electromagnetic proportional valve is controlled so as to have an area.
- FIG. 1 is a side view of the hydraulic excavator according to the first embodiment.
- FIG. 2 is a diagram showing a hydraulic system (hydraulic drive circuit) included in the hydraulic excavator according to the first embodiment.
- FIG. 3 is a diagram showing the opening characteristics of the center bypass passage portion and the meter-in passage portion of the flow control valve.
- FIG. 4 is a diagram showing the opening characteristics of the bypass cut valve.
- FIG. 5 is a block diagram showing the calculation processing of the control current value of the electromagnetic proportional valve by the controller of the hydraulic excavator according to the first embodiment.
- FIG. 6 is a diagram showing the target opening characteristics of the bypass cut valve.
- FIG. 7 is a time chart showing the time change of the opening area of each valve and the pressure of the hydraulic oil when the boom return operation is performed in the hydraulic excavator according to the comparative example of the first embodiment.
- FIG. 8 is a time chart showing the time change of the opening area of each valve and the pressure of the hydraulic oil when the boom return operation is performed in the hydraulic excavator according to the first embodiment.
- FIG. 9 is a diagram showing a hydraulic system (hydraulic drive circuit) included in the hydraulic excavator according to the second embodiment.
- FIG. 10 is a block diagram showing a calculation process of a control current value of an electromagnetic proportional valve by a controller of a hydraulic excavator according to a second embodiment.
- FIG. 11 is a diagram showing the first target opening characteristic and the second target opening characteristic of the bypass cut valve.
- FIG. 12 is a time chart showing the time change of the opening area of each valve and the pressure of the hydraulic oil when the boom raising operation is performed in the hydraulic excavator according to the first embodiment
- FIG. 12A is a time chart showing the temperature of the hydraulic oil. It is a time chart when T is equal to or more than a threshold value T0, and (b) is a time chart when the temperature T of the hydraulic oil is less than the threshold value T0.
- FIG. 13 is a time chart showing the time change of the opening area of each valve and the pressure of the hydraulic oil when the boom raising operation is performed in the hydraulic excavator according to the second embodiment.
- FIG. 12 is a time chart showing the time change of the opening area of each valve and the pressure of the hydraulic oil when the boom raising operation is performed in the hydraulic excavator according to the second embodiment.
- FIG. 14 is a diagram showing a hydraulic system (hydraulic drive circuit) included in the hydraulic excavator according to the third embodiment.
- FIG. 15 is a block diagram showing a calculation process of a control current value of an electromagnetic proportional valve by a controller of a hydraulic excavator according to a third embodiment.
- the working machine according to the embodiment of the present invention will be described with reference to the drawings.
- the work machine performs civil engineering work, construction work, demolition work, dredging work, and the like at the work site.
- FIG. 1 is a side view of the hydraulic excavator 100 according to the first embodiment of the present invention.
- the hydraulic excavator 100 includes a machine body 105 and a working device 104 attached to the machine body 105.
- the machine body 105 has a crawler type traveling body 102 and a turning body 103 provided on the traveling body 102 so as to be able to turn.
- the traveling body 102 travels by driving a pair of left and right crawlers by a traveling motor 102A.
- the swivel body 103 is connected to the traveling body 102 via a swivel device having a swivel motor 103A, and is driven by the swivel motor 103A to rotate (turn) with respect to the traveling body 102.
- the swivel body 103 includes a driver's cab 118 on which the operator is boarded, and an engine chamber in which the engine and hydraulic equipment such as a hydraulic pump driven by the engine are housed.
- the engine is a power source of the hydraulic excavator 100, and is composed of an internal combustion engine such as a diesel engine.
- the working device 104 is an articulated working device attached to the swivel body 103, and has a plurality of hydraulic actuators and a plurality of driven members (front members) driven by the plurality of hydraulic actuators.
- the working device 104 has a configuration in which three driven members (boom 111, arm 112, and bucket 113) are connected in series.
- the base end portion of the boom 111 is rotatably connected to the front portion of the swivel 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.
- the bucket 113 is rotatably connected to the tip of the arm 112 via a bucket pin.
- the boom 111 is rotationally driven by the expansion / contraction operation of the boom cylinder 111A, which is a hydraulic actuator (hydraulic cylinder).
- the arm 112 is rotationally driven by the expansion / contraction operation of the arm cylinder 112A, which is a hydraulic actuator (hydraulic cylinder).
- the bucket 113 is rotationally driven by the expansion / contraction operation of the bucket cylinder 113A, which is a hydraulic actuator (hydraulic cylinder).
- FIG. 2 is a diagram showing a hydraulic system (hydraulic drive circuit) included in the hydraulic excavator 100 according to the first embodiment.
- FIG. 2 shows only the part related to the drive of the boom cylinder 111A, and omits the other parts related to the drive of the hydraulic actuator.
- the hydraulic system includes a tank 4 in which hydraulic oil, which is a hydraulic fluid, is stored, and a main pump 1 and a pilot pump 9 that are driven by an engine (not shown) and discharge hydraulic oil sucked from the tank 4.
- the boom cylinder 111A driven by the hydraulic fluid discharged from the main pump 1, the center bypass line 171 connecting the main pump 1 and the tank 4, the flow control valve 130 provided in the center bypass line 171 and the center.
- a bypass cut valve 6 provided on the downstream side of the flow control valve 130 in the bypass line 171, an electromagnetic proportional valve 7 for generating a pilot pressure for controlling the bypass cut valve 6, and an operating device 180 for operating the boom cylinder 111A.
- the controller 150 as a control device for controlling each part of the hydraulic excavator 100, and the pressure sensors 185A and 185B for detecting the pilot pressure acting on the pilot pressure receiving parts 136 and 137 of the flow control valve 130 are provided.
- the center bypass line 171 is an oil passage that guides the hydraulic oil supplied from the main pump 1 to the tank 4 via the center bypass passage portion 131 of the flow control valve 130.
- the main pump 1 is a variable capacity hydraulic pump whose discharge capacity (pushing volume) can be changed, and the pilot pump 9 is a fixed capacity hydraulic pump having a constant discharge capacity.
- the main pump 1 may be a fixed capacity hydraulic pump.
- the flow rate control valve 130 controls the direction and flow rate of the hydraulic oil supplied from the main pump 1 to the boom cylinder 111A.
- the flow control valve 130 is located in the neutral position when the tank pressure is applied to each of the pilot pressure receiving unit 136 and the pilot pressure receiving unit 137.
- the flow rate control valve 130 is an open center type control valve, and is supplied from the center bypass passage portion 131 that guides the hydraulic oil from the main pump 1 to the tank 4 through the center bypass line 171 and the operation supplied from the main pump 1 in a neutral position. It has a meter-in passage portion 132 that guides oil to the boom cylinder 111A, and a meter-out passage portion 133 that guides hydraulic oil (return oil) supplied from the boom cylinder 111A to the tank 4.
- the flow rate control valve 130 controls the flow rate of the hydraulic oil supplied to the boom cylinder 111A according to the displacement amount (spool stroke) from the neutral position. The larger the displacement of the flow control valve 130 from the neutral position, the higher the speed of the boom cylinder 111A. Further, when the flow rate control valve 130 moves from the neutral position to one side, the boom cylinder 111A expands, and when the flow rate control valve 130 moves from the neutral position to the other side, the boom cylinder 111A contracts. That is, the flow rate control valve 130 controls the drive direction and speed of the boom cylinder 111A.
- the operation device 180 is an operation device for operating the boom 111 (boom cylinder 111A, flow rate control valve 130), and the flow rate control valve 130 is operated based on the operation lever 181 which is an operation member and the operation amount of the operation lever 181. It has a boom raising pilot valve 182 and a boom lowering pilot valve 183 that generate a controlled pilot pressure (hereinafter, also referred to as an operating pressure).
- the operating device 180 generates a pilot pressure (operating pressure) according to the operating direction and operating amount of the operating lever 181 by the pilot valves 182, 183, and the pilot pressure generated by the pilot valves 182, 183 is used in the flow control valve 130. It is a hydraulic pilot type operating device that is directly supplied.
- the operating lever 181 is provided, for example, on the right side of the driver's seat (see FIG. 1) and is operated in the front-rear direction. When the operating lever 181 is operated backward, the boom 111 operates in the upward direction. When the operating lever 181 is operated forward, the boom 111 operates in the downward direction.
- the boom raising pilot valve 182 reduces the pilot primary pressure supplied from the pilot pump 9 and generates a pilot pressure (operating pressure) according to the operating amount (lever stroke) of the operating lever 181 in the boom raising direction.
- the operating pressure output from the pilot valve 182 for raising the boom is guided to the pilot pressure receiving unit 136 on one side (right side in the figure) of the flow rate control valve 130 via the pilot oil passage, and drives the flow rate control valve 130 to the left in the figure. do.
- the hydraulic oil discharged from the main pump 1 is supplied to the bottom side oil chamber 111b of the boom cylinder 111A through the meter-in passage portion 132 of the flow rate control valve 130, and the hydraulic oil in the rod side oil chamber 111r is flow controlled. It is discharged to the tank 4 through the meter-out passage portion 133 of the valve 130.
- the boom cylinder 111A is extended.
- the boom lowering pilot valve 183 reduces the pilot primary pressure supplied from the pilot pump 9 and generates a pilot pressure (operating pressure) according to the operating amount (lever stroke) of the operating lever 181 in the boom lowering direction.
- the operating pressure output from the pilot valve 183 for lowering the boom is guided to the pilot pressure receiving portion 137 on the other side (left side in the figure) of the flow rate control valve 130 via the pilot oil passage, and drives the flow rate control valve 130 to the right in the figure. do.
- the hydraulic oil discharged from the main pump 1 is supplied to the rod side oil chamber 111r of the boom cylinder 111A through the meter-in passage portion of the flow rate control valve 130, and the hydraulic oil in the bottom side oil chamber 111b is supplied to the flow rate control valve. It is discharged to the tank 4 through the meter-out passage portion of 130. As a result, the boom cylinder 111A contracts.
- FIG. 3 is a diagram showing the opening characteristic A1c of the center bypass passage portion 131 of the flow control valve 130 and the opening characteristic A2c of the meter-in passage portion 132.
- the horizontal axis shows the operating pressure Po (pilot pressure generated by the pilot valve 182) acting on the pilot pressure receiving portion 136
- the vertical axis shows the opening area A1 of the center bypass passage portion 131 and the opening of the meter-in passage portion 132.
- the area A2 is shown.
- the operating pressure Po generally corresponds to the stroke amount of the flow control valve 130.
- the pressure of the pilot pressure receiving unit 137 is the minimum pressure (tank pressure).
- the center bypass passage portion 131 As shown in FIG. 3, when the flow control valve 130 is located in the neutral position, that is, when the operating pressure Po acting on the pilot pressure receiving portion 136 is the minimum pressure (tank pressure), the center bypass passage portion 131.
- the opening area A1 is the maximum opening area A1max, and the meter-in passage portion 132 is fully closed (that is, the opening area A2 is 0).
- the stroke amount of the flow control valve 130 increases.
- the opening area A2 of the meter-in passage portion 132 becomes larger, and the opening area A1 of the center bypass passage portion 131 becomes smaller.
- the center bypass passage portion 131 is fully closed (that is, the opening area A1 is 0).
- the change in the opening area A1 with respect to the operating pressure Po of the center bypass passage portion 131 and the change in the opening area A2 with respect to the operating pressure Po of the meter-in passage portion 132 have an inverse relationship.
- the opening characteristic of the meter-out passage portion 133 is substantially the same as the opening characteristic A2c of the meter-in passage portion 132.
- the bypass cut valve 6 is a hydraulic pilot type control valve capable of controlling the opening of the center bypass line 171.
- the bypass cut valve 6 has a pilot pressure receiving portion 6a on which the pilot pressure (secondary pressure) generated by the electromagnetic proportional valve 7 acts, and is controlled by the pilot pressure acting on the pilot pressure receiving portion 6a.
- the electromagnetic proportional valve 7 is provided in the pilot oil passage connecting the pilot pump 9 driven by the engine (not shown) and the pilot pressure receiving portion 6a of the bypass cut valve 6.
- the electromagnetic proportional valve 7 reduces the pilot primary pressure supplied from the pilot pump 9 and generates a pilot pressure according to the control current from the controller 150.
- the electromagnetic proportional valve 7 is a pressure reducing valve whose degree of decompression decreases as the input control current increases. Therefore, when the control current input to the electromagnetic proportional valve 7 increases, the secondary pressure (pilot pressure) increases according to the control current.
- FIG. 4 is a diagram showing the opening characteristic A3c of the bypass cut valve 6.
- the horizontal axis shows the pilot pressure acting on the pilot pressure receiving portion 6a (the pilot pressure generated by the electromagnetic proportional valve 7), and the vertical axis shows the opening area A3 of the bypass cut valve 6.
- the pilot pressure acting on the pilot pressure receiving portion 6a is the minimum pressure (tank pressure)
- the bypass cut valve 6 is positioned at the fully open position by the force of the spring.
- the pilot pressure acting on the pilot pressure receiving portion 6a becomes a predetermined pressure Pp3 or more, the bypass cut valve 6 is located at the shutoff position.
- the opening area A3 of the bypass cut valve 6 When the bypass cut valve 6 is located at the cutoff position, the center bypass line 171 is cut off (that is, the opening area A3 becomes 0). As the pilot pressure Pp acting on the pilot pressure receiving portion 6a increases, the opening area A3 of the bypass cut valve 6 becomes smaller.
- the opening area A3 of the bypass cut valve 6 has a minimum opening area A3min (A3min> 0) according to the magnitude of the operating pressure Po. It is controlled within the range of the maximum opening area A3max or less (see FIG. 6).
- the pressure sensor 185A detects the operating pressure Po output from the pilot valve 182 for raising the boom when the boom raising operation is performed by the operating lever 181 and outputs the detection result to the controller 150. do.
- the pressure sensor 185B detects the operating pressure Po output from the pilot valve 183 for lowering the boom when the boom lowering operation is performed by the operating lever 181 and outputs the detection result to the controller 150.
- the operating pressure Po detected by the pressure sensors 185A and 185B has a correlation (proportional relationship) with the operating amount of the operating lever 181. Therefore, the pressure sensors 185A and 185B have a function as an operation amount detection device for detecting the operation amount of the operation device 180.
- the controller 150 is a control device that controls the electromagnetic proportional valve 7 based on the operating pressure Po (corresponding to the operating amount of the operating device 180) detected by the pressure sensors 185A and 185B.
- the controller 150 is a processor 151 such as a CPU (Central Processing Unit), an MPU (Micro Processing Unit), a DSP (Digital Signal Processor), a ROM (Read Only Memory), a flash memory, a non-volatile memory 152 such as a hard disk drive, a so-called RAM. It is composed of a computer equipped with a volatile memory 153 called (RandomAccessMemory), an input interface 154, an output interface 155, and other peripheral circuits.
- the controller 150 may be configured by one computer or may be configured by a plurality of computers.
- the non-volatile memory 152 stores a program capable of executing various operations. That is, the non-volatile memory 152 is a storage medium capable of reading a program that realizes the functions of the present embodiment.
- the processor 151 is a processing device that expands the program stored in the non-volatile memory 152 into the volatile memory 153 and executes an operation, and signals taken from the input interface 154, the non-volatile memory 152, and the volatile memory 153 according to the program. Performs predetermined arithmetic processing on the.
- the input interface 154 converts the input signal so that the processor 151 can calculate it. Further, the output interface 155 generates an output signal according to the calculation result of the processor 151, and outputs the signal to a device such as the electromagnetic proportional valve 7.
- FIG. 5 is a block diagram showing the calculation processing of the control current value of the electromagnetic proportional valve 7 by the controller 150 of the hydraulic excavator 100 according to the first embodiment, and shows the calculation processing when the boom raising operation is performed.
- the controller 150 has an opening area calculation unit 161, a pilot pressure calculation unit 162, and a current calculation unit 163.
- the functions of the opening area calculation unit 161 and the pilot pressure calculation unit 162 and the current calculation unit 163 are exhibited by executing the program stored in the non-volatile memory 152 by the processor 151.
- the opening area calculation unit 161 refers to the target opening characteristic A3tc stored in advance in the non-volatile memory 152, and based on the operating pressure Po detected by the pressure sensor 185A, the target value of the opening area A3 of the bypass cut valve 6 The target opening area A3t is calculated.
- FIG. 6 is a diagram showing the target opening characteristic A3tc of the bypass cut valve 6. Note that FIG. 6 also shows the opening characteristic A1c of the center bypass passage portion 131 of the flow control valve 130 with a broken line. As shown in FIG. 6, the target opening characteristic A3tc is a characteristic of the target opening area A3t of the bypass cut valve 6 with respect to the operating pressure Po acting on the pilot pressure receiving unit 136, and is stored in the non-volatile memory 152 in a table format. ..
- the relationship between the operating pressure Po defined by the target opening characteristic A3tc and the target opening area A3t is as follows.
- the target opening area A3t of the bypass cut valve 6 becomes the minimum opening area A3min according to the increase in the operating pressure Po. It becomes smaller until it becomes.
- the target opening area A3t is the maximum opening area A3max.
- the target opening area A3t of the bypass cut valve 6 becomes continuously smaller as the operating pressure Po increases, and the operating pressure Po becomes the first operation.
- the minimum opening area is A3min.
- the target opening area A3t of the bypass cut valve 6 is the minimum opening area A3min.
- the target opening area A3t of the bypass cut valve 6 increases from the minimum opening area A3min to the predetermined opening area A30.
- the target opening area A3t of the bypass cut valve 6 is a predetermined opening area A30 in the range where the operating pressure Po is equal to or less than the second operating pressure Po2 and the maximum operating pressure Pox or less.
- the predetermined opening area A30 is larger than the minimum opening area A3min and is a value equal to or less than the maximum opening area A3max.
- the pilot pressure calculation unit 162 refers to the target pilot pressure characteristic Cp stored in advance in the non-volatile memory 152, and is based on the target opening area A3t calculated by the opening area calculation unit 161.
- the target pilot pressure Ppt which is the target value of the pilot pressure Pp generated by the electromagnetic proportional valve 7, is calculated.
- the target pilot pressure characteristic Cp is a characteristic in which the target pilot pressure Ppt decreases as the target opening area A3t increases, and is stored in the non-volatile memory 152 in a table format.
- the current calculation unit 163 refers to the control current characteristic Ci stored in advance in the non-volatile memory 152, and supplies the current to the solenoid of the electromagnetic proportional valve 7 based on the target pilot pressure Ppt calculated by the pilot pressure calculation unit 162.
- the control current value Ic is calculated, and the control current according to the calculation result is output to the electromagnetic proportional valve 7.
- the control current characteristic Ci is a characteristic in which the control current value Ic increases as the target pilot pressure Ppt increases.
- the crane work (suspended load work) performed by the hydraulic excavator 100 will be described as an example.
- a wire is hung on a hook provided on the back of the bucket 113 of the hydraulic excavator 100 to lift the suspended load.
- the suspended load is moved in the vertical direction by raising and lowering the boom 111.
- the oil chamber 111b on the bottom side of the boom cylinder 111A becomes the load holding side.
- the boom cylinder 111A When the operator operates the operation lever 181 to the boom raising side, the boom cylinder 111A extends and the boom 111 rotates upward. After that, when the operator returns the operation lever 181 to the neutral position, the boom cylinder 111A decelerates and stops.
- the opening area of the center bypass line 171 is set in the region from the minimum operating pressure Po to the second operating pressure Po2 in which the center bypass passage portion 131 of the flow control valve 130 is fully closed. It is the combined opening area (effective area) of the opening area of the flow control valve 130 and the opening area of the bypass cut valve 6. This combined opening area is smaller than the opening area A1 of the center bypass passage portion 131.
- the opening area A3 of the bypass cut valve 6 is larger than the minimum opening area A3min.
- the electromagnetic proportional valve 7 is controlled so as to be A30.
- FIG. 7 is a time chart showing the time change of the opening area of each valve and the pressure of the hydraulic oil when the boom return operation is performed in the hydraulic excavator according to the comparative example of the first embodiment.
- FIG. 8 is a time chart showing the time change of the opening area of each valve and the pressure of the hydraulic oil when the boom return operation is performed in the hydraulic excavator according to the first embodiment.
- the time charts shown in FIGS. 7 and 8 are time charts in the case where the operation lever 181 is operated to the boom raising side up to the maximum operation amount and then the operation lever 181 is returned to the neutral position.
- the time change of the opening area A1 of the center bypass passage portion 131 of the flow control valve 130, the opening area A2 of the meter-in passage portion 132, and the opening area A3 of the bypass cut valve 6 is shown. Shows. Further, in the lower time chart showing the change in pressure, the discharge pressure (also referred to as pump pressure) Ppu of the main pump 1, the hydraulic oil pressure (also referred to as bottom pressure) Pb of the bottom side oil chamber 111b of the boom cylinder 111A, And the time change of the pressure (also referred to as rod pressure) Pr of the hydraulic oil in the rod side oil chamber 111r of the boom cylinder 111A is shown.
- the hydraulic excavator according to the comparative example of the first embodiment has the same configuration as the hydraulic excavator 100 according to the first embodiment, but is stored in the non-volatile memory 152.
- the target opening characteristic A3tcc is different from the target opening characteristic A3tc described in the first embodiment.
- the target opening characteristic A3tcc according to the comparative example is a characteristic in which the operating pressure Po is in the range of the second operating pressure Po2 or more and the maximum operating pressure Pox or less, and the target opening area At is the minimum opening area A3min.
- the bypass cut valve 6 starts to open after a delay time ⁇ t1 from the time point t11 when the center bypass passage portion 131 of the flow control valve 130 starts to open. As described above, the reason why the responsiveness of the flow rate control valve 130 and the bypass cut valve 6 are different will be described.
- the flow control valve 130 starts the return operation when the pilot pressure (operation pressure) output from the pilot valve 182 decreases due to the return operation of the operation lever 181.
- the bypass cut valve 6 starts the return operation when the pilot pressure output from the electromagnetic proportional valve 7 decreases.
- the electromagnetic proportional valve 7 is controlled based on the control current output from the controller 150.
- the controller 150 detects that the operating pressure Po detected by the pressure sensor 185A has decreased, and then outputs the control current corresponding to the operating pressure Po to the electromagnetic proportional valve 7.
- the operation of the bypass cut valve 6 is controlled by the controller 150. Therefore, one of the causes of the response delay is the time required for communication and arithmetic processing from the acquisition of the detection result of the operating pressure Po to the output of the control current to the electromagnetic proportional valve 7. Further, the time from the input of the control current to the electromagnetic proportional valve 7 to the change of the pilot pressure acting on the pilot pressure receiving portion 6a of the bypass cut valve 6 is also mentioned as one of the causes of the response delay.
- the flow rate control valve 130 is not controlled by the controller 150, but is directly controlled by the operating pressure output from the operating device 180 in response to the operator's operation. For this reason, the operation of the bypass cut valve 6 is delayed from the operation of the flow rate control valve 130.
- the bypass cut valve 6 is closed even if the opening area A1 of the center bypass passage portion 131 of the flow control valve 130 increases.
- the pump pressure Ppu rises.
- the bottom pressure Pb which is the pressure of the hydraulic oil in the bottom side oil chamber 111b of the boom cylinder 111A connected to the main pump 1 at the meter-in passage portion 132, also increases.
- the bottom pressure Pb becomes high, the braking force for decelerating the boom cylinder 111A (rod pressure Pr ⁇ pressure receiving area of the rod side oil chamber 111r-bottom pressure Pb ⁇ pressure receiving area of the bottom side oil chamber 111b) becomes weak.
- the meter-in passage portion 132 and the meter-out passage portion 133 are closed while the speed of the boom cylinder 111A is high, and a surge pressure is generated in the rod-side oil chamber 111r (time point t12). ..
- surge pressure is generated when the boom cylinder 111A is stopped, impact and vibration will be generated in the working device 104, which makes it difficult to position the working device 104. Further, when an impact or vibration is generated in the working device 104, it leads to an increase in operator fatigue. Therefore, the generation of surge pressure may lead to a decrease in work efficiency of the hydraulic excavator 100.
- the opening area A3 of the bypass cut valve 6 becomes the predetermined opening area A30.
- the opening area A3 of the bypass cut valve 6 becomes the predetermined opening area A30 in the state where the operating lever 181 is operated up to the maximum operating amount on the boom raising side. ing.
- the delay time is from t21 when the flow control valve 130 starts the return operation until the bypass cut valve 6 starts to open (until the opening area A3 of the bypass cut valve 6 starts to increase).
- ⁇ t2 is generated, it is possible to prevent the surge pressure from being generated in the rod side oil chamber 111r by opening the bypass cut valve 6 in advance. That is, in the first embodiment, since it is possible to prevent the working device 104 from being impacted or vibrated, the working device 104 can be easily positioned. Further, in the first embodiment, it is possible to prevent the working device 104 from being shocked or vibrated, so that the operator's fatigue can be reduced. As a result, the efficiency of work by the hydraulic excavator 100 can be improved.
- the hydraulic excavator (working machine) 100 includes a main pump (pump) 1 for discharging the hydraulic oil sucked from the tank 4 and a boom cylinder (hydraulic actuator) 111A driven by the hydraulic oil discharged from the main pump 1. And, it has a center bypass passage portion 131 that guides the hydraulic oil from the main pump 1 to the tank 4 in the neutral position, and controls the flow rate of the hydraulic oil supplied to the boom cylinder 111A according to the amount of displacement from the neutral position.
- the control valve 130, the center bypass line 171 that guides the hydraulic oil supplied from the main pump 1 to the tank 4 via the center bypass passage portion 131 of the flow control valve 130, and the flow control valve 130 in the center bypass line 171.
- a bypass cut valve 6 provided on the downstream side for controlling the opening of the center bypass line 171, an electromagnetic proportional valve 7 for generating a pilot pressure for controlling the bypass cut valve 6, and an operating device 180 for operating the boom cylinder 111A.
- a pilot valve 182 that generates an operating pressure (pilot pressure) that controls the flow control valve 130 based on the operating amount of the operating device 180, and a pressure sensor (operating amount) that detects the operating pressure (operating amount) of the operating device 180.
- a detection device) 185A and a controller (control device) 150 that controls the electromagnetic proportional valve 7 based on the operating pressure Po detected by the pressure sensor 185A.
- the opening area A3 of the bypass cut valve 6 becomes the minimum opening according to the increase in the operating pressure Po.
- the electromagnetic proportional valve 7 is controlled so as to be small until the area becomes A3 min. As a result, the energy loss of the main pump 1 is reduced and the fuel efficiency is improved. Moreover, good fine operability can be obtained.
- the controller 150 When the operating pressure Po detected by the pressure sensor 185A is the maximum operating pressure Pox, the controller 150 has an opening area (predetermined opening area A30) in which the opening area A3 of the bypass cut valve 6 is larger than the minimum opening area A3min. As described above, the electromagnetic proportional valve 7 is controlled. This makes it possible to prevent the generation of surge pressure when the boom cylinder (hydraulic actuator) 111A is stopped. As a result, the work efficiency of the hydraulic excavator 100 can be improved.
- the opening area A1 of the center bypass passage portion 131 of the flow control valve 130 becomes smaller as the operating pressure Po increases in the range where the operating pressure Po is less than the second operating pressure Po2, and is fully closed at the second operating pressure Po2. It has an opening characteristic A1c.
- the controller 150 increases the opening area A3 of the bypass cut valve 6 from the minimum opening area A3min when the operating pressure Po detected by the pressure sensor 185A is equal to or greater than the second operating pressure Po2 and equal to or less than the maximum operating pressure Pox.
- the electromagnetic proportional valve 7 is controlled.
- the energy loss can be reduced as compared with the case where the operating pressure Po is less than the second operating pressure Po2 and the opening area A3 of the bypass cut valve 6 is increased from the minimum opening area A3min.
- FIG. 9 is a diagram similar to FIG. 2, and is a diagram showing a hydraulic system (hydraulic drive circuit) included in the hydraulic excavator 200 according to the second embodiment.
- the hydraulic excavator 200 according to the second embodiment has the same configuration as the hydraulic excavator 100 according to the first embodiment, and is a temperature sensor that detects the temperature of the hydraulic oil passing through the bypass cut valve 6. It is equipped with 286.
- the temperature sensor 286 detects the temperature of the hydraulic oil in the tank 4 in which the hydraulic oil sucked up by the main pump 1 is stored.
- the installation location of the temperature sensor 286 is not limited to the tank 4.
- FIG. 10 is a diagram similar to FIG. 5, and is a block diagram showing the calculation processing of the control current value of the electromagnetic proportional valve 7 by the controller 250 of the hydraulic excavator 200 according to the second embodiment.
- the controller 250 has a first opening area calculation unit 261A, a second opening area calculation unit 261B, a selection unit 264, a pilot pressure calculation unit 162, and a current calculation unit 163.
- the first opening area calculation unit 261A has the same function as the opening area calculation unit 161 described in the first embodiment.
- the first opening area calculation unit 261A refers to the first target opening characteristic A3ac and calculates the target opening area A3t of the bypass cut valve 6 based on the operating pressure Po detected by the pressure sensor 185A.
- the second opening area calculation unit 261B refers to the second target opening characteristic A3bc different from the first target opening characteristic A3ac, and based on the operating pressure Po detected by the pressure sensor 185A, the target opening area of the bypass cut valve 6 Calculate A3t.
- FIG. 11 is a diagram showing the first target opening characteristic A3ac and the second target opening characteristic A3bc of the bypass cut valve 6.
- the first target opening characteristic A3ac and the second target opening characteristic A3bc are stored in the non-volatile memory 152 in a table format.
- a thin solid line shows the first target opening characteristic A3ac
- a thick solid line shows the second target opening characteristic A3bc.
- FIG. 11 is a diagram showing the first target opening characteristic A3ac and the second target opening characteristic A3bc of the bypass cut valve 6.
- a thin solid line shows the first target opening characteristic A3ac
- a thick solid line shows the second target opening characteristic A3bc.
- FIG. 11 is a diagram
- the opening characteristic A1c of the center bypass passage portion 131 of the flow control valve 130 is also shown by the broken line. Since the first target opening characteristic A3ac has the same characteristics as the target opening characteristic A3tc described in the first embodiment, the description thereof will be omitted.
- the relationship between the operating pressure Po defined by the second target opening characteristic A3bc and the target opening area A3t is as follows.
- the target opening area A3t is the maximum opening area A3max.
- the target opening area A3t of the bypass cut valve 6 becomes continuously smaller until the minimum opening area A3min2 is reached as the operating pressure Po increases.
- the minimum opening area A3min2 in the second target opening characteristic A3bc is larger than the minimum opening area A3min2 in the first target opening characteristic A3ac.
- the target opening area A3t of the bypass cut valve 6 is a predetermined opening area A30 larger than the minimum opening area A3min2.
- the rate of change (inclination) of the target opening area A3t with respect to the operating pressure Po in the range where the operating pressure Po is the minimum operating pressure Po or more and less than the third operating pressure Po3, and the range of the third operating pressure Po3 or more and less than the second operating pressure Po2. It is different from the rate of change (inclination) of the target opening area A3t with respect to the operating pressure Po in.
- the magnitude relationship of each operating pressure is Pon ⁇ Po3 ⁇ Po1 ⁇ Po2 ⁇ Pox.
- the target opening area A3t defined by the second target opening characteristic A3bc is larger than the target opening area A3t defined by the first target opening characteristic A3ac. big.
- the selection unit 264 determines whether or not the temperature T of the hydraulic oil detected by the temperature sensor 286 is equal to or higher than the threshold value T0.
- the threshold value T0 is a threshold value for determining whether or not the hydraulic oil is in a low temperature state, and is stored in the non-volatile memory 152 in advance.
- the selection unit 264 selects the target opening area A3t calculated by the first opening area calculation unit 261A and outputs the target opening area A3t to the pilot pressure calculation unit 162.
- the selection unit 264 determines that the temperature T of the hydraulic oil is less than the threshold value T0, the selection unit 264 selects the target opening area A3t calculated by the second opening area calculation unit 261B and outputs the target opening area A3t to the pilot pressure calculation unit 162. It should be noted that the present invention is not limited to this, and for example, the target opening area A3t may be selected as a three-dimensional table by inputting the operating pressure and the hydraulic oil temperature.
- the pilot pressure calculation unit 162 calculates the target pilot pressure Ppt based on the target opening area A3t selected by the selection unit 264.
- the current calculation unit 163 calculates the control current value Ic based on the target pilot pressure Ppt calculated by the pilot pressure calculation unit 162, and outputs the control current according to the calculation result to the electromagnetic proportional valve 7.
- the crane work (suspended load work) performed by the hydraulic excavator 200 will be described as an example.
- the boom cylinder 111A extends and the boom 111 rotates upward.
- the operator smoothly lifts the suspended load by the work device 104.
- the controller 150 bypass cuts more than when it is high (T ⁇ T0).
- the electromagnetic proportional valve 7 is controlled so that the opening area A3 of the valve 6 becomes large.
- the boom cylinder 111A can be smoothly operated without causing a shock.
- the point that the boom cylinder 111A can be operated without generating a shock during the boom raising operation according to the configuration of the second embodiment will be described in comparison with the first embodiment.
- FIGS. 12 (a) and 12 (b) are time charts showing the time change of the opening area of each valve and the pressure of the hydraulic oil when the boom raising operation is performed in the hydraulic excavator 100 according to the first embodiment.
- FIG. 12A is a time chart when the temperature T of the hydraulic oil is equal to or higher than the threshold value T0
- FIG. 12B is a time chart when the temperature T of the hydraulic oil is less than the threshold value T0
- FIG. 13 is a time chart showing the time change of the opening area of each valve and the pressure of the hydraulic oil when the boom raising operation is performed in the hydraulic excavator 200 according to the second embodiment. The time charts shown in FIGS.
- 12 (a), 12 (b) and 13 are time charts when the operation lever 181 is operated from the neutral position to the boom raising side.
- the upper time chart showing the change in the opening area the time change of the opening area A1 of the center bypass passage portion 131 of the flow control valve 130, the opening area A2 of the meter-in passage portion 132, and the opening area A3 of the bypass cut valve 6 is shown. Shows.
- the lower time chart showing the change in pressure shows the time change of the pump pressure Ppu, the bottom pressure Pb of the boom cylinder 111A, and the rod pressure Pr of the boom cylinder 111A.
- the flow control valve 130 is displaced from the neutral position.
- the opening area A1 of the center bypass passage portion 131 and the opening area A3 of the bypass cut valve 6 gradually decrease from the time point t31.
- the meter-in passage portion 132 starts to open from the time point t32, and the opening area A2 of the meter-in passage portion 132 increases as the operation amount increases.
- the pump pressure Ppu gradually increases from the time point t31.
- the pump pressure Ppu exceeds the bottom pressure Pb just before t32 when the meter-in passage portion 132 begins to open. In this way, by adjusting the pump pressure pp when the meter-in passage portion 132 opens to the bottom pressure Pb, the operation of the boom cylinder 111A can be started smoothly. Therefore, the boom 111 can be slowly operated to raise the suspended load.
- the bypass cut valve 6 when the hydraulic oil temperature T is less than the threshold value T0, the bypass cut valve 6 is more than when the hydraulic oil temperature T is equal to or higher than the threshold value T0.
- the electromagnetic proportional valve 7 is controlled so that the opening area A3 of the above is large. Therefore, in the second embodiment, as shown in FIG. 13, the opening area A1 of the center bypass passage portion 131 and the opening of the bypass cut valve 6 are opened from the time t51 when the operation of the operating lever 181 is started from the neutral position to the boom raising side. Although the area A3 decreases, the decrease rate of the opening area A3 of the bypass cut valve 6 decreases at the time point t52.
- the time point t52 is a time point before the time point when the meter-in passage portion 132 starts to open. From the time point t52 to the time point t53 when the center bypass passage portion 131 is fully closed, the opening area A3 of the bypass cut valve 6 when the hydraulic oil temperature T is less than the threshold value T0 is when the hydraulic oil temperature T is equal to or higher than the threshold value T0. It becomes larger than the opening area A3 of. As a result, the pressure loss when the hydraulic oil passes through the center bypass passage portion 131 and the bypass cut valve 6 of the flow rate control valve 130 is reduced, so that a sudden increase in the pump pressure Ppu is prevented. As a result, a sudden increase in the bottom pressure Pb is also prevented.
- the second embodiment when the temperature of the hydraulic oil is low, it is possible to prevent the working device 104 from suddenly starting to operate, so that the working device 104 can be easily positioned. be able to. Further, in the second embodiment, when the temperature of the hydraulic oil is low, it is possible to prevent the working device 104 from suddenly starting to operate, so that the operator's fatigue can be reduced. As a result, the work efficiency of the hydraulic excavator 200 can be improved.
- FIG. 14 is a diagram similar to FIGS. 2 and 9, and is a diagram showing a hydraulic system (hydraulic drive circuit) included in the hydraulic excavator 300 according to the third embodiment.
- the hydraulic excavator 300 is provided with a plurality of flow rate control valves 130A and 130B on the center bypass line 171.
- the flow rate control valve 130A and the flow rate control valve 130B connected in tandem have the same configuration as the flow rate control valve 130 described in the first embodiment.
- the flow rate control valve 130A controls the flow direction and flow rate of the hydraulic oil supplied to the boom cylinder 111A
- the flow rate control valve 130B controls the flow direction and flow rate of the hydraulic oil supplied to the arm cylinder 112A.
- the hydraulic excavator 300 includes an operating device 380 for operating the arm cylinder 112A, and pressure sensors 385A and 385B for detecting the pilot pressure acting on the pilot pressure receiving portions 136 and 137 of the flow control valve 130B.
- the operation device 380 is an operation device for operating the arm 112 (arm cylinder 112A, flow rate control valve 130B), and the flow rate control valve 130B is operated based on the operation amount of the operation lever 381 and the operation lever 381 which are operation members. It has a pilot valve 382 for an arm cloud and a pilot valve 383 for an arm dump that generate a pilot pressure (operating pressure) to be controlled.
- the operation device 380 generates a pilot pressure (operation pressure) according to the operation direction and operation amount of the operation lever 381 by the pilot valves 382, 383, and the pilot pressure generated by the pilot valves 382, 383 is used in the flow control valve 130B. It is a hydraulic pilot type operating device that is directly supplied.
- the operation lever 381 is provided, for example, on the left side of the driver's seat (see FIG. 1) and is operated in the left-right direction.
- an arm dump operation is performed.
- the arm dump operation is an operation in which the arm 112 rotates so that the tip of the arm 112 is separated from the machine body 105.
- the operation lever 381 is operated to the right, the arm cloud operation is performed.
- the arm cloud operation is an operation in which the arm 112 rotates so that the tip of the arm 112 approaches the machine body 105.
- the pressure sensor 385A detects the operation pressure Po output from the pilot valve 382 for the arm cloud when the arm cloud operation is performed by the operation lever 381, and outputs the detection result to the controller 350.
- the pressure sensor 385B detects the operating pressure Po output from the pilot valve 383 for the arm dump when the arm dump operation is performed by the operating lever 381, and outputs the detection result to the controller 350.
- the opening area (composite opening area) of the center bypass line 171 is narrowed as compared with the case where the single operation is performed. Be done. Therefore, among the plurality of flow rate control valves 130A and 130B connected in tandem, the supply side pressure of the boom cylinder 111A to which hydraulic oil is supplied from the flow rate control valve 130A on the upstream side of the center bypass line 171 becomes higher than necessary. .. Therefore, as in the case where the temperature of the hydraulic oil described in the second embodiment is low, a shock may occur at the start of operation of the boom cylinder 111A.
- the controller 350 is electromagnetically arranged so that when a plurality of flow control valves 130A and 130B are operated in combination, the opening area A3 of the bypass cut valve 6 becomes larger than when the plurality of flow control valves 130A and 130B are operated independently.
- the proportional valve 7 is controlled.
- FIG. 15 is a diagram similar to FIGS. 5 and 10, and is a block diagram showing the calculation processing of the control current value of the electromagnetic proportional valve 7 by the controller 350 of the hydraulic excavator 300 according to the third embodiment.
- the controller 350 has a selection unit 364 instead of the selection unit 264 described in the second embodiment.
- the selection unit 364 determines whether or not the flow control valve 130A and the flow control valve 130B are in a combined operation state at the same time based on the operation pressure Po detected by the pressure sensors 185A, 185B, 385A, and 385B. do.
- one of the operating pressures Po detected by the pressure sensors 185A and 185B has a threshold value Po0 or more, and one of the operating pressures detected by the pressure sensors 385A and 385B has a threshold value Po0 or more. If there is, it is determined that it is in the combined operation state, and in other cases, it is determined that it is not in the combined operation state.
- the threshold value Po0 is a threshold value for determining whether or not the operating devices 180 and 380 are being operated, and is stored in a predetermined non-volatile memory 152.
- the selection unit 364 selects the target opening area A3t calculated by the first opening area calculation unit 261A and outputs it to the pilot pressure calculation unit 162.
- the selection unit 364 selects the target opening area A3t calculated by the second opening area calculation unit 261B and outputs it to the pilot pressure calculation unit 162.
- the operation pressure is not limited to this, and for example, the operation pressure output from the operation device 180 and the operation pressure output from the operation device 380 are input to select the target opening area A3t as a three-dimensional table. May be good.
- the center bypass line 171 is provided with a plurality of flow rate control valves 130A and 130B.
- the controller 350 controls the electromagnetic proportional valve 7 so that the opening area A3 of the bypass cut valve 6 becomes larger when the plurality of flow control valves 130A and 130B are operated in combination than when they are operated independently.
- the third embodiment when a plurality of flow rate control valves 130A and 130B are operated in combination, it is possible to prevent the working device 104 from suddenly starting operation, so that the working device 104 can be prevented from starting operation. Positioning can be easily performed. Further, in the third embodiment, when a plurality of flow rate control valves 130A and 130B are operated in combination, it is possible to prevent the working device 104 from suddenly starting to operate, thus reducing operator fatigue. be able to. As a result, the efficiency of work by the hydraulic excavator 300 can be improved.
- the controller 150 increases the opening area A3 of the bypass cut valve 6 from the minimum opening area A3min when the operating pressure Po detected by the pressure sensor 185A is the second operating pressure Po2.
- the electromagnetic proportional valve 7 has been described above, the present invention is not limited thereto.
- the controller 150 may control the electromagnetic proportional valve 7 so that the opening area A3 of the bypass cut valve 6 increases from the minimum opening area A3min when the operating pressure Po is larger than the second operating pressure Po2.
- the electromagnetic proportional valve 7 is controlled so that the opening area A3 of the bypass cut valve 6 increases from the minimum opening area A3min. By doing so, energy loss can be reduced.
- the controller 150 may control the electromagnetic proportional valve 7 so that the opening area A3 of the bypass cut valve 6 increases from the minimum opening area A3min when the operating pressure Po is less than the second operating pressure Po2.
- the operating device 180 may be an electric operating device.
- the operation amount of the electric operation device is detected by an operation amount detection device such as a potentiometer that detects the rotation angle of the operation lever.
- the controller 150 outputs a control current to the electromagnetic proportional valve (pilot valve) based on the operation amount detected by the operation amount detection device.
- the electromagnetic proportional valve (pilot valve) reduces the pilot primary pressure supplied from the pilot pump 9 to generate a pilot pressure (operating pressure), and the generated pilot pressure (operating pressure) is used as a pilot pressure receiving unit of the flow control valve 130. Output to 136, 137.
- the electromagnetic proportional valve 7 that controls the bypass cut valve 6 and the electromagnetic proportional valve (pilot valve) that controls the flow rate control valve 130 are controlled by the controller 150, so that there is a difference in responsiveness. Hateful. However, there is a difference in length between the pilot oil passage connecting the pilot pressure receiving portion 136 of the flow control valve 130 and the electromagnetic proportional valve (pilot valve) and the pilot oil passage connecting the bypass cut valve 6 and the electromagnetic proportional valve 7. , And the operation of the bypass cut valve 6 may be delayed as compared with the operation of the flow rate control valve 130 due to differences in valve characteristics and the like. Therefore, the same effect as that described in the above embodiment can be obtained even for a hydraulic excavator having an electric operating device.
- ⁇ Modification example 4> In the above embodiment, the case where the work machine is a crawler type hydraulic excavator 100 has been described as an example, but the present invention is not limited thereto. The present invention can be applied to various work machines such as wheel type hydraulic excavators and wheel loaders.
- center bypass line 180 ... operation device, 181 ... operation lever (operation member), 182, 183 ... Pilot valve, 185A, 185B ... Pressure sensor (operation amount detection device), 200 ... Hydraulic excavator (working machine), 250 ... Controller (control device), 261A ... First opening area calculation unit, 261B ... Second opening area Calculation unit, 264 ... selection unit, 286 ... temperature sensor, 300 ... hydraulic excavator (working machine), 350 ... controller (control device), 364 ... selection unit, 380 ... operation device, 381 ... operation lever (operation member), 382 , 383 ... Pilot valve, 385A, 385B ... Pressure sensor (operation amount detection device), A1 ... Center bypass passage opening area, A1c ...
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Abstract
Description
図1は、本発明の第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に取り付けられる作業装置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に対して回動する(旋回する)。
図9から図13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、図中、第1実施形態と同一もしくは相当部分には同一の参照番号を付し、相違点を主に説明する。図9は、図2と同様の図であり、第2実施形態に係る油圧ショベル200が備える油圧システム(油圧駆動回路)について示す図である。図9に示すように、第2実施形態に係る油圧ショベル200は、第1実施形態に係る油圧ショベル100と同様の構成に加え、バイパスカット弁6を通過する作動油の温度を検出する温度センサ286を備えている。
図14及び図15を参照して、第3実施形態に係る油圧ショベル300について説明する。なお、図中、第2実施形態と同一もしくは相当部分には同一の参照番号を付し、相違点を主に説明する。図14は、図2及び図9と同様の図であり、第3実施形態に係る油圧ショベル300が備える油圧システム(油圧駆動回路)について示す図である。
上記第1実施形態では、コントローラ150は、圧力センサ185Aで検出された操作圧Poが、第2操作圧Po2であるときに、バイパスカット弁6の開口面積A3が最小開口面積A3minから増加するように電磁比例弁7を制御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。
コントローラ150は、操作圧Poが第2操作圧Po2よりも大きいときに、バイパスカット弁6の開口面積A3が最小開口面積A3minから増加するように電磁比例弁7を制御してもよい。上述したように、操作圧Poが、第2操作圧Po2以上最大操作圧Pox以下であるときに、バイパスカット弁6の開口面積A3が最小開口面積A3minから増加するように電磁比例弁7を制御することにより、エネルギーロスを低減することができる。
コントローラ150は、操作圧Poが第2操作圧Po2未満のときに、バイパスカット弁6の開口面積A3が最小開口面積A3minから増加するように電磁比例弁7を制御してもよい。なお、バイパスカット弁6の開口面積A3が最小開口面積A3minから増加する操作圧Poは低いほどエネルギーロスが発生する。このため、バイパスカット弁6の開口面積A3が最小開口面積A3minから増加する操作圧Poは、高い方が(すなわち第2操作圧Po2に近い方が)好ましい。
上記第1実施形態では、操作装置180が、油圧パイロット式の操作装置である例について説明したが、本発明はこれに限定されない。操作装置180は、電気式の操作装置であってもよい。電気式の操作装置の操作量は、操作レバーの回動角度を検出するポテンショメータ等の操作量検出装置によって検出される。コントローラ150は、操作量検出装置で検出された操作量に基づいて、電磁比例弁(パイロット弁)に制御電流を出力する。電磁比例弁(パイロット弁)は、パイロットポンプ9から供給されるパイロット一次圧を減圧してパイロット圧(操作圧)を生成し、生成したパイロット圧(操作圧)を流量制御弁130のパイロット受圧部136,137に出力する。このような構成では、バイパスカット弁6を制御する電磁比例弁7と、流量制御弁130を制御する電磁比例弁(パイロット弁)は、それぞれコントローラ150によって制御されるので、応答性に差が生じにくい。しかしながら、流量制御弁130のパイロット受圧部136と電磁比例弁(パイロット弁)とを接続するパイロット油路と、バイパスカット弁6と電磁比例弁7とを接続するパイロット油路との長さの違い、及び弁の特性の違い等により、バイパスカット弁6の動作が、流量制御弁130の動作に比べて遅れることもある。したがって、電気式の操作装置を有する油圧ショベルに対しても、上記実施形態で説明した効果と同様の効果を得ることができる。
上記第1実施形態では、ブームシリンダ111Aにおけるサージ圧の発生を防止するための構成について説明したが、本発明はこれに限定されない。アームシリンダ112A及びバケットシリンダ113Aにおけるサージ圧の発生も同様に防止することができる。
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)
- タンクから吸引した作動油を吐出するポンプと、
前記ポンプから吐出された作動油によって駆動される油圧アクチュエータと、
中立位置で前記ポンプからの作動油を前記タンクに導くセンタバイパス通路部を有し、前記中立位置からの変位量に応じて前記油圧アクチュエータへ供給される作動油の流量を制御する流量制御弁と、
前記ポンプから供給された作動油を、前記流量制御弁の前記センタバイパス通路部を経由して前記タンクに導くセンタバイパスラインと、
前記センタバイパスラインにおける前記流量制御弁の下流側に設けられ前記センタバイパスラインの開口を制御するバイパスカット弁と、
前記バイパスカット弁を制御するパイロット圧を生成する電磁比例弁と、
前記油圧アクチュエータを操作するための操作装置と、
前記操作装置の操作量に基づいて、前記流量制御弁を制御するパイロット圧を生成するパイロット弁と、
前記操作装置の操作量を検出する操作量検出装置と、
前記操作量検出装置で検出された操作量に基づいて、前記電磁比例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、
前記操作量検出装置で検出された操作量が、最小操作量以上所定操作量未満の範囲では、前記操作量の増加に応じて前記バイパスカット弁の開口面積が最小開口面積となるまで小さくなるように前記電磁比例弁を制御し、
前記操作量検出装置で検出された操作量が、最大操作量であるときには、前記バイパスカット弁の開口面積が前記最小開口面積よりも大きい開口面積となるように、前記電磁比例弁を制御する
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、
前記流量制御弁の前記センタバイパス通路部は、前記操作量が前記所定操作量未満の範囲では前記操作量が増加するほど開口面積が小さくなり、前記所定操作量で全閉となる開口特性を有し、
前記制御装置は、前記操作量検出装置で検出された操作量が、前記所定操作量以上前記最大操作量以下であるときに、前記バイパスカット弁の開口面積が前記最小開口面積から増加するように前記電磁比例弁を制御する
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、
前記バイパスカット弁を通過する作動油の温度を検出する温度センサを備え、
前記制御装置は、前記温度センサで検出された作動油の温度が低いときには、高いときよりも前記バイパスカット弁の開口面積が大きくなるように、前記電磁比例弁を制御する
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、
前記センタバイパスラインには、複数の前記流量制御弁が設けられ、
前記制御装置は、前記複数の流量制御弁が複合操作されたときには、単独操作されたときよりも前記バイパスカット弁の開口面積が大きくなるように、前記電磁比例弁を制御する
ことを特徴とする作業機械。
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Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP2011085198A (ja) | 2009-10-15 | 2011-04-28 | Hitachi Constr Mach Co Ltd | 作業機械の油圧システム |
JP2012229777A (ja) | 2011-04-27 | 2012-11-22 | Yuken Kogyo Co Ltd | ブームシリンダ昇降用油圧回路 |
JP2017057926A (ja) * | 2015-09-16 | 2017-03-23 | キャタピラー エス エー アール エル | 油圧作業機における油圧ポンプ制御システム |
US20170130427A1 (en) * | 2015-11-05 | 2017-05-11 | Caterpillar Inc. | Device and Process for Controlling and Optimizing Hydraulic System Performance |
JP2019148318A (ja) * | 2018-02-28 | 2019-09-05 | 川崎重工業株式会社 | 建設機械の油圧システム |
JP2020153461A (ja) * | 2019-03-20 | 2020-09-24 | 日立建機株式会社 | 油圧ショベル |
Family Cites Families (1)
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JP7305968B2 (ja) | 2019-01-28 | 2023-07-11 | コベルコ建機株式会社 | 作業機械における油圧シリンダの駆動装置 |
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- 2021-11-11 JP JP2022571951A patent/JP7472321B2/ja active Active
- 2021-11-11 EP EP21910026.0A patent/EP4191073A4/en active Pending
- 2021-11-11 KR KR1020237006762A patent/KR20230041809A/ko unknown
- 2021-11-11 CN CN202180052603.4A patent/CN115989353A/zh active Pending
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Patent Citations (6)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP2011085198A (ja) | 2009-10-15 | 2011-04-28 | Hitachi Constr Mach Co Ltd | 作業機械の油圧システム |
JP2012229777A (ja) | 2011-04-27 | 2012-11-22 | Yuken Kogyo Co Ltd | ブームシリンダ昇降用油圧回路 |
JP2017057926A (ja) * | 2015-09-16 | 2017-03-23 | キャタピラー エス エー アール エル | 油圧作業機における油圧ポンプ制御システム |
US20170130427A1 (en) * | 2015-11-05 | 2017-05-11 | Caterpillar Inc. | Device and Process for Controlling and Optimizing Hydraulic System Performance |
JP2019148318A (ja) * | 2018-02-28 | 2019-09-05 | 川崎重工業株式会社 | 建設機械の油圧システム |
JP2020153461A (ja) * | 2019-03-20 | 2020-09-24 | 日立建機株式会社 | 油圧ショベル |
Non-Patent Citations (1)
Title |
---|
See also references of EP4191073A4 |
Cited By (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP7379631B1 (ja) | 2022-09-30 | 2023-11-14 | 日立建機株式会社 | 作業機械 |
WO2024070905A1 (ja) * | 2022-09-30 | 2024-04-04 | 日立建機株式会社 | 作業機械 |
JP2024052330A (ja) * | 2022-09-30 | 2024-04-11 | 日立建機株式会社 | 作業機械 |
Also Published As
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US20230304262A1 (en) | 2023-09-28 |
KR20230041809A (ko) | 2023-03-24 |
JPWO2022137872A1 (ja) | 2022-06-30 |
EP4191073A4 (en) | 2024-08-28 |
JP7472321B2 (ja) | 2024-04-22 |
CN115989353A (zh) | 2023-04-18 |
EP4191073A1 (en) | 2023-06-07 |
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