WO2019188061A1 - Hydraulic circuit for work vehicle - Google Patents

Hydraulic circuit for work vehicle Download PDF

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Publication number
WO2019188061A1
WO2019188061A1 PCT/JP2019/008773 JP2019008773W WO2019188061A1 WO 2019188061 A1 WO2019188061 A1 WO 2019188061A1 JP 2019008773 W JP2019008773 W JP 2019008773W WO 2019188061 A1 WO2019188061 A1 WO 2019188061A1
Authority
WO
WIPO (PCT)
Prior art keywords
pressure
switching valve
actuator
command
pilot
Prior art date
Application number
PCT/JP2019/008773
Other languages
French (fr)
Japanese (ja)
Inventor
松山　博志
崇之 白水
和央 青山
拓郎 藤原
Original Assignee
ヤンマー株式会社
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by ヤンマー株式会社 filed Critical ヤンマー株式会社
Priority to KR1020207007942A priority Critical patent/KR102642076B1/en
Priority to EP19778403.6A priority patent/EP3779212A4/en
Priority to AU2019246449A priority patent/AU2019246449A1/en
Publication of WO2019188061A1 publication Critical patent/WO2019188061A1/en

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    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
    • F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
    • F15B11/00—Servomotor systems without provision for follow-up action; Circuits therefor
    • F15B11/16—Servomotor systems without provision for follow-up action; Circuits therefor with two or more servomotors
    • F15B11/161—Servomotor systems without provision for follow-up action; Circuits therefor with two or more servomotors with sensing of servomotor demand or load
    • F15B11/166—Controlling a pilot pressure in response to the load, i.e. supply to at least one user is regulated by adjusting either the system pilot pressure or one or more of the individual pilot command pressures
    • 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
    • E02F3/425—Drive systems for dipper-arms, backhoes or the like
    • 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
    • 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
    • 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
    • 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
    • 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
    • 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
    • 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
    • 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
    • F15B11/08—Servomotor systems without provision for follow-up action; Circuits therefor with only one servomotor
    • 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
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
    • F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
    • F15B11/00—Servomotor systems without provision for follow-up action; Circuits therefor
    • F15B11/16—Servomotor systems without provision for follow-up action; Circuits therefor with two or more servomotors
    • F15B11/17—Servomotor systems without provision for follow-up action; Circuits therefor with two or more servomotors using two or more pumps
    • 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
    • F15B11/167—Servomotor systems without provision for follow-up action; Circuits therefor with two or more servomotors with sensing of servomotor demand or load using pilot pressure to sense the demand
    • 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
    • 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
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
    • F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
    • F15B2211/00—Circuits for servomotor systems
    • F15B2211/30—Directional control
    • F15B2211/305—Directional control characterised by the type of valves
    • F15B2211/3056—Assemblies of multiple valves
    • F15B2211/3059—Assemblies of multiple valves having multiple valves for multiple output members
    • F15B2211/30595—Assemblies of multiple valves having multiple valves for multiple output members with additional valves between the groups of valves for multiple output members
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
    • F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
    • F15B2211/00—Circuits for servomotor systems
    • F15B2211/30—Directional control
    • F15B2211/32—Directional control characterised by the type of actuation
    • F15B2211/329—Directional control characterised by the type of actuation actuated by fluid pressure
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
    • F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
    • F15B2211/00—Circuits for servomotor systems
    • F15B2211/30—Directional control
    • F15B2211/355—Pilot pressure control
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
    • F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
    • F15B2211/00—Circuits for servomotor systems
    • F15B2211/30—Directional control
    • F15B2211/36—Pilot pressure sensing
    • 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
    • F15B2211/50554—Pressure control characterised by the type of pressure control means the pressure control means controlling a pressure downstream of the pressure control means, e.g. pressure reducing valve
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
    • F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
    • F15B2211/00—Circuits for servomotor systems
    • F15B2211/50—Pressure control
    • F15B2211/52—Pressure control characterised by the type of actuation
    • F15B2211/526—Pressure control characterised by the type of actuation electrically or electronically
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
    • F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
    • F15B2211/00—Circuits for servomotor systems
    • F15B2211/50—Pressure control
    • F15B2211/575—Pilot pressure control
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
    • F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
    • F15B2211/00—Circuits for servomotor systems
    • F15B2211/60—Circuit components or control therefor
    • F15B2211/63—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
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
    • F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
    • F15B2211/00—Circuits for servomotor systems
    • F15B2211/60—Circuit components or control therefor
    • F15B2211/635—Circuits providing pilot pressure to pilot pressure-controlled fluid circuit elements
    • F15B2211/6355—Circuits providing pilot pressure to pilot pressure-controlled fluid circuit elements having valve means
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
    • F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
    • F15B2211/00—Circuits for servomotor systems
    • F15B2211/60—Circuit components or control therefor
    • F15B2211/665—Methods of control using electronic components
    • F15B2211/6653—Pressure control
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
    • F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
    • F15B2211/00—Circuits for servomotor systems
    • F15B2211/70—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
    • 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
    • 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
    • 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
    • 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
    • F15B2211/78—Control of multiple output members

Definitions

  • the present invention relates to a hydraulic circuit for a work vehicle.
  • Patent Document 1 in a construction machine including a hydraulic control circuit for driving a plurality of hydraulic actuators including a traveling actuator, a single operation of the traveling actuator is changed to a combined operation of the traveling actuator and another actuator.
  • a combined operation with another actuator is performed while the travel actuator is operating
  • the pilot pressure is applied to the pilot pressure receiving part on the inlet side of the direction switching valve by reducing the return pressure of the pilot pressure oil acting on the pilot pressure receiving part on the return side of the direction switching valve.
  • a technique for preventing discloses a sharp reduction of the flow rate of the hydraulic fluid supplied to the traveling actuator.
  • Patent Document 2 as a technique for preventing adverse effects such as deterioration in operability while securing a buffering action during sudden operation, a pilot that guides a secondary pressure corresponding to an operation amount to a pilot port of a control valve as a pilot pressure.
  • a pilot that guides a secondary pressure corresponding to an operation amount to a pilot port of a control valve as a pilot pressure.
  • a first throttle and a pilot line are connected to a tank on the primary side of the pressure reducing valve.
  • the flow control valve is installed in the return oil path of the pilot pressure oil that acts on the pilot pressure receiving portion on the return side of the direction switching valve to throttle the return oil. Therefore, it is necessary to install a flow rate control valve for each remote control valve that controls the operation, which increases the cost.
  • the pilot pressure oil is throttled for each pressure receiving portion of the direction switching valve. There is no need to arrange the means, but since the bleed offline having the second throttle for gradual rise of the pilot pressure is arranged on the secondary side of the pressure reducing valve, the bleed offline is arranged for each pressure receiving part of the direction switching valve. There is a problem that the cost rises because it is necessary to arrange in the.
  • the present invention provides a method for reducing the amount of oil generated when shifting from a single operation for driving a single hydraulic actuator to a combined operation for driving a plurality of hydraulic actuators in a work vehicle including a plurality of hydraulic actuators.
  • An object of the present invention is to provide a hydraulic circuit of a work vehicle that can prevent a shock due to a sudden drop with an inexpensive configuration.
  • a hydraulic circuit for a work vehicle includes a first actuator, a second actuator, a hydraulic pump that supplies pressure oil to the first actuator and the second actuator, and pressure oil that is supplied to the first actuator.
  • a first direction switching valve for switching the direction and adjusting the flow rate; a second direction switching valve for switching the direction of the pressure oil supplied to the second actuator; and the first direction switching valve and the second direction.
  • a pilot pump for supplying pilot pressure oil to the switching valve; a first operating device capable of switching and adjusting the direction and pressure of the pilot pressure oil supplied to the first direction switching valve according to an operation; and the second direction switching.
  • a second operating device capable of switching and adjusting a direction and pressure of pilot pressure oil supplied to the valve according to an operation; and an oil between the second operating device and the pilot pump.
  • a pressure controller for controlling the primary pressure of the pilot pressure oil supplied to the second operating unit, and a control command transmitter which transmits a control command to the pressure control device
  • the control command transmission device transmits a first command for reducing and holding the primary pressure from a reference pressure to a first command pressure to the pressure control device while the first operation device is being operated.
  • a second command for gradually increasing the primary pressure from the first command pressure to the second command pressure with respect to the pressure control device. Is to send.
  • the control command transmission device when the second operating device is not operated while the first operating device is operated, the control command transmission device sends the primary pressure to the pressure control device when the second command is not operated.
  • a command for gradually decreasing the pressure to the first command pressure may be transmitted.
  • the first actuator may be a first traveling hydraulic motor
  • the second actuator may be a working hydraulic actuator
  • a first circuit system including a first hydraulic pump for supplying pressure oil to the first traveling hydraulic motor and the first traveling hydraulic motor, the working hydraulic actuator, a second traveling hydraulic motor, And a second circuit system including a second hydraulic pump that supplies pressure oil to the working hydraulic actuator and the second traveling hydraulic motor, and pressure oil of the first circuit system and pressure oil of the second circuit system. And a merging switching valve for merging.
  • the pilot supplied to the second operating device corresponding to the second actuator when shifting from a single operation for driving only the first actuator to a combined operation for simultaneously driving the first actuator and the second actuator, the pilot supplied to the second operating device corresponding to the second actuator. Since the pressure oil pressure is gradually increased from the first command pressure to the second command pressure, it is possible to prevent a shock due to a rapid decrease in the amount of pressure oil supplied to the first actuator.
  • the control of the present invention can be applied to a plurality of actuators simply by installing a branch path to a plurality of operation devices on the downstream side of the pressure control device, it is possible to provide a hydraulic circuit with an inexpensive configuration. it can.
  • FIG. 1 shows a hydraulic circuit 100 according to the first embodiment.
  • the hydraulic circuit 100 includes a first actuator 11, a second actuator 12, a hydraulic pump 13, a pilot pump 14, a first direction switching valve 15, a second direction switching valve 16, a first operating device 17, A second operating device 18.
  • the first actuator 11 is a hydraulic motor that is driven by pressure oil supplied from the hydraulic pump 13.
  • the second actuator 12 is a hydraulic cylinder driven by the pressure oil supplied from the hydraulic pump 13.
  • the first actuator 11 may be a hydraulic cylinder
  • the second actuator 12 may be a hydraulic motor.
  • the hydraulic pump 13 is driven by an engine (not shown) and discharges pressure oil.
  • the pressure oil discharged from the hydraulic pump 13 is supplied to the first direction switching valve 15 and the second direction switching valve 16 through the oil passage 13a and the oil passage 13b.
  • the oil passage of the pressure oil supplied from the hydraulic pump 13 to the first actuator 11 and the second actuator 12 is indicated by a solid line.
  • the first direction switching valve 15 is a pilot-type direction switching valve capable of switching the direction of the pressure oil supplied to the first actuator 11 and adjusting the flow rate.
  • the second direction switching valve 16 is a pilot-type direction switching valve capable of switching the direction of the pressure oil supplied to the second actuator 12 and adjusting the flow rate.
  • the pilot pump 14 discharges pilot pressure oil as a command input to the first direction switching valve 15 and the second direction switching valve 16.
  • the oil passage of pilot pressure oil supplied from the pilot pump 14 to the first directional switching valve 15 and the second directional switching valve 16 is indicated by broken lines.
  • the pilot pump 14 generates a pilot pressure applied to the first directional switching valve 15 and the second directional switching valve 16.
  • the pilot pump 14 is driven by an engine (not shown) and generates a pilot pressure in the oil passage 14a by discharging pressure oil.
  • the oil passage 14a is branched into oil passages 14b, 14c, 14d, and 14e.
  • the first direction switching valve 15 can be switched to a plurality of positions by sliding the spool.
  • pilot pressure is not applied to either the pilot port 15a or the pilot port 15b of the first direction switching valve 15, the first direction switching valve 15 is held in the neutral position by the biasing force of the spring.
  • the 1st direction switching valve 15 exists in a neutral position, pressure oil is not supplied to the 1st actuator 11 from the oil path 13b.
  • the first directional switching valve 15 when a pilot pressure is applied to the pilot port 15a or the pilot port 15b of the first directional switching valve 15, the first directional switching valve 15 is switched from the neutral position to another position, and the pressure oil flows through the oil passage 11a. Alternatively, it is supplied to the first actuator 11 through the oil passage 11b. The first actuator 11 is driven to rotate in the forward direction or the reverse direction by the pressure oil supplied via the oil passage 11a or the oil passage 11b.
  • the second direction switching valve 16 can be switched to a plurality of positions by sliding the spool.
  • pilot pressure is not applied to either the pilot port 16a or the pilot port 16b of the second direction switching valve 16
  • the second direction switching valve 16 is held in the neutral position by the biasing force of the spring.
  • the pressure oil is not supplied to the second actuator 12 from the oil passage 13a.
  • the second direction switching valve 16 is switched from the neutral position to another position, and the pressure oil is supplied to the oil passage 12a. Or it is supplied to the second actuator 12 via the oil passage 12b.
  • the second actuator 12 expands and contracts by the pressure oil supplied through the oil passage 12a or the oil passage 12b.
  • the first direction switching valve 15 is provided with a first detection direction switching valve 15c.
  • the first detection direction switching valve 15c can be switched to a plurality of positions by sliding the spool. When the first direction switching valve 15 is held at the neutral position, the first detection direction switching valve 15c is also held at the neutral position. When the first direction switching valve 15 is switched from the neutral position to another position, the first detection direction switching valve 15c is also switched from the neutral position to another position in conjunction with this.
  • the first detection direction switching valve 15c When the first detection direction switching valve 15c is in the neutral position, the first detection direction switching valve 15c does not block the oil passage 14b. Therefore, the pressure oil can flow through the oil passage 14b via the first detection direction switching valve 15c. On the other hand, when the first detection direction switching valve 15c is in a position other than the neutral position, the first detection direction switching valve 15c closes the oil passage 14b.
  • a first pressure switch 141 is connected to the oil passage 14b.
  • the oil passage 14b is closed and pressure is generated in the throttle downstream portion of the oil passage 14b. This pressure is configured to be detected by the first pressure switch 141.
  • the first pressure switch 141 detects that the first operating device 17 has been operated, and outputs this detection signal to the ECU 10 described later.
  • the second direction switching valve 16 includes a second detection direction switching valve 16c.
  • the second detection direction switching valve 16c can be switched to a plurality of positions by sliding the spool. When the second direction switching valve 16 is held at the neutral position, the second detection direction switching valve 16c is also held at the neutral position. When the second direction switching valve 16 is switched from the neutral position to another position, the second detection direction switching valve 16c is also switched from the neutral position to another position in conjunction with this.
  • the second detection direction switching valve 16c When the second detection direction switching valve 16c is in the neutral position, the second detection direction switching valve 16c does not block the oil passage 14c. Therefore, the pressure oil can flow through the oil passage 14c via the second detection direction switching valve 16c. On the other hand, when the second detection direction switching valve 16c is in a position other than the neutral position, the second detection direction switching valve 16c closes the oil passage 14c.
  • a second pressure switch 142 is connected to the oil passage 14c.
  • the oil passage 14c is closed and pressure is generated in the throttle downstream portion of the oil passage 14c. This pressure is configured to be detected by the second pressure switch 142.
  • the second pressure switch 142 detects that the second operating device 18 has been operated, and outputs this detection signal to the ECU 10 described later.
  • the first operating device 17 has a first remote control valve 170 for switching the direction and pressure of the pilot pressure oil supplied to the first direction switching valve 15.
  • the first remote control valve 170 is connected to the oil passage 14d.
  • the first remote control valve 170 is connected to the pilot port 15a and the pilot port 15b of the first direction switching valve 15 via the oil passage 17a and the oil passage 17b, respectively.
  • the first remote control valve 170 supplies the pressure oil supplied from the pilot pump 14 via the oil passage 14d to the first direction switching valve 15 as pilot pressure oil.
  • the second operating device 18 has a second remote control valve 180 for switching the direction and pressure of the pilot pressure oil supplied to the second direction switching valve 16.
  • the second remote control valve 180 is connected to the oil passage 14e.
  • the second remote control valve 180 is connected to the pilot port 16a and the pilot port 16b of the second direction switching valve 16 via the oil passage 18a and the oil passage 18b, respectively.
  • the second remote control valve 180 supplies the pressure oil supplied from the pilot pump 14 via the oil passage 14e to the second direction switching valve 16 as pilot pressure oil.
  • an electromagnetic pressure reducing valve 19 (an example of a pressure control device) is provided in the oil passage 14e between the second remote control valve 180 and the pilot pump 14.
  • the electromagnetic pressure reducing valve 19 can control the primary pressure of the pilot pressure oil discharged from the pilot pump 14 and supplied to the second remote control valve 180.
  • the electromagnetic pressure reducing valve 19 can control the pressure according to the magnitude of the input current.
  • the hydraulic circuit 100 includes an ECU 10 (an example of a control command transmission device) that transmits a control command to the electromagnetic pressure reducing valve 19.
  • the ECU 10 issues a control command in accordance with the operation of the first operating device 17 and the second operating device 18.
  • the ECU 10 determines that the first operating device 17 is operated by receiving a detection signal from the first pressure switch 141, and receives the detection signal from the second pressure switch 142 to receive the second operating device 18. Can be determined to be operated.
  • FIG. 2 shows how the primary pressure of the pilot pressure oil supplied to the second remote control valve 180 is controlled.
  • the ECU 10 When the first operating device 17 is operated (time A in FIG. 2), the ECU 10 reduces the primary pressure of the pilot pressure oil from the reference pressure to the first command pressure with respect to the electromagnetic pressure reducing valve 19, While the operating device 17 is being operated (time AB in FIG. 2), a first command for holding the primary pressure of the pilot pressure oil at the first command pressure is transmitted to the electromagnetic pressure reducing valve 19.
  • the reference pressure is the pressure of the pressure oil discharged from the pilot pump 14.
  • the ECU 10 applies the primary pressure of the pilot pressure oil to the electromagnetic pressure reducing valve 19.
  • a second command for gradually increasing the first command pressure to the second command pressure is transmitted.
  • the second command pressure is higher than the first command pressure and lower than the reference pressure.
  • the ratio of the reference pressure, the first command pressure, and the second command pressure is set as appropriate.
  • the time for gradually increasing from the first command pressure to the second command pressure is also set as appropriate.
  • the primary pressure of the pilot pressure oil is set to the second command pressure with respect to the electromagnetic pressure reducing valve 19. Send the command to hold to. Accordingly, when the single operation for driving only the first actuator 11 is shifted to the combined operation for simultaneously driving the first actuator 11 and the second actuator 12, the second direction switching valve 16 is switched to the second direction switching valve 16 via the second remote control valve 180. In order to gradually increase the applied pilot pressure from the first command pressure to the second command pressure, the pressure oil from the hydraulic pump 13 is supplied to the first actuator 11 without being suddenly supplied to the second actuator 12. Shock due to a sudden drop in the amount of pressurized oil can be prevented.
  • the ECU 10 applies the primary pressure of the pilot pressure oil to the electromagnetic pressure reducing valve 19.
  • a command for gradually decreasing the pressure from the second command pressure to the first command pressure is transmitted.
  • a command for holding the primary pressure of the pilot pressure oil at the first command pressure is given to the electromagnetic pressure reducing valve 19. send.
  • the ECU 10 increases the primary pressure from the pilot pump 14 from the first command value to the reference value with respect to the electromagnetic pressure reducing valve 19. Send the command to hold.
  • the excavator 1 includes a traveling device 2, a work device 3, and a turning device 4.
  • the traveling device 2 is driven by receiving power from the engine 42 and causes the excavator 1 to travel.
  • the traveling device 2 includes a pair of left and right crawlers 21 and 21 and a pair of left and right traveling motors 22L and 22R.
  • the left and right traveling motors 22L and 22R which are hydraulic motors, drive the left and right crawlers 21 and 21, respectively, so that the hydraulic excavator 1 can move forward and backward.
  • the traveling device 2 is provided with a blade 23 and a blade cylinder 24 that is a hydraulic actuator for rotating the blade 23 in the vertical direction.
  • the working device 3 is driven by receiving power from the engine 42 and performs excavation work such as earth and sand.
  • the working device 3 includes a boom 31, an arm 32, and a bucket 33, and enables them to perform excavation work by driving them independently.
  • the boom 31, the arm 32, and the bucket 33 each correspond to a working unit, and the excavator 1 has a plurality of working units.
  • the boom 31 is pivoted by a boom cylinder 31a, one end of which is supported by the front portion of the turning device 4 and movable in a telescopic manner.
  • the arm 32 is supported by the other end of the boom 31 at one end and is rotated by an arm cylinder 32a that is movable in a telescopic manner.
  • the bucket 33 is rotated by a bucket cylinder 33a that is supported at one end by the other end of the arm 32 and is movable in a telescopic manner.
  • the boom cylinder 31a, the arm cylinder 32a, and the bucket cylinder 33a correspond to hydraulic actuators that drive the working unit.
  • the turning device 4 turns the work device 3.
  • the turning device 4 includes a control unit 41, an engine 42, a turntable 43, a turn motor 44, and the like.
  • a swing motor 44 which is a hydraulic motor, drives the swivel base 43 to swing the work device 3.
  • the swing device 4 is provided with a plurality of hydraulic pumps (not shown in FIG. 3) driven by the engine 42. These hydraulic pumps supply pressure oil to the boom cylinder 31a, the arm cylinder 32a, the bucket cylinder 33a, and the like.
  • a pilot seat 411 is disposed in the pilot unit 41.
  • a pair of work operation levers 412L and 412R are disposed on the left and right sides of the cockpit 411, and a pair of travel levers 413L and 413R are disposed on the front side.
  • the operator sits on the cockpit 411 and operates the operation control levers 412L and 412R, the travel levers 413L and 413R, etc. to control the engine 42, each hydraulic motor, each hydraulic actuator, etc. Etc. can be performed.
  • a hydraulic circuit 5 included in the hydraulic excavator 1 will be described with reference to FIG.
  • the hydraulic circuit 5 includes first to third hydraulic actuators 121, 122, 123 (boom cylinder 31a, arm cylinder 32a, bucket cylinder 33a), left traveling motor 22L, right traveling motor 22R, turning motor 44, and first hydraulic pump. 51, a second hydraulic pump 52, a direction switching valve 53, a pilot pump 54, and a remote control valve 55.
  • FIG. 4 for convenience of explanation, circuits relating to the blade cylinder 24 and the like are omitted.
  • the first hydraulic pump 51 mainly supplies pressure oil to the right traveling motor 22R, the third hydraulic actuator 123, and the turning motor 44.
  • the second hydraulic pump 52 mainly supplies pressure oil to the first hydraulic actuator 121, the second hydraulic actuator 122, and the left traveling motor 22L.
  • the direction switching valve 53 is provided corresponding to each hydraulic actuator, and is configured to be able to switch the direction and flow rate of the pressure oil supplied from the first hydraulic pump 51 and the second hydraulic pump 52 to the hydraulic actuator. Yes.
  • the plurality of directional control valves 53 are collectively referred to as a control valve.
  • a first hydraulic actuator direction switching valve 53 a corresponding to the first hydraulic actuator 121
  • a second hydraulic actuator direction switching valve 53 b corresponding to the second hydraulic actuator 122
  • a left travel motor direction switching valve 53c corresponding to the travel motor 22L
  • a right travel motor direction switching valve 53d corresponding to the right travel motor 22R
  • a third hydraulic actuator direction switching valve 53e corresponding to the third hydraulic actuator 123.
  • a turning direction switching valve 53 f corresponding to the turning motor 44. Since the structure of the direction switching valve 53 is the same as that of the first direction switching valve 15 and the second direction switching valve 16 of the first embodiment, detailed description thereof is omitted.
  • the direction switching valve 53 includes a detection direction switching valve.
  • the detection direction switching valves provided in the left traveling motor direction switching valve 53c and the right traveling motor direction switching valve 53d respectively close or open the oil passage 54a from the pilot pump 54.
  • the detection direction switching valves provided in the first hydraulic actuator direction switching valve 53a, the second hydraulic actuator direction switching valve 53b, the third hydraulic actuator direction switching valve 53e, and the turning direction switching valve 53f, respectively Then, the oil passage 54b from the pilot pump 54 is closed or opened. Since the structure of the detection direction switching valve is the same as that of the first detection direction switching valve 15c and the second detection direction switching valve 16c of the first embodiment, detailed description thereof is omitted.
  • a first pressure switch 141 is connected to the oil passage 54a.
  • the first pressure switch 141 detects the pressure that is closed and a pressure is generated in the downstream portion of the throttle of the oil passage 54a.
  • the first pressure switch 141 detects that the travel levers 413L and 413R are operated, and outputs a detection signal to the ECU 10.
  • a second pressure switch 142 is connected to the oil passage 54b.
  • the oil passage 54b is closed and the oil passage 54b is throttled downstream.
  • a pressure is generated in the part, and this pressure is detected by the second pressure switch 142.
  • the second pressure switch 142 detects that the work operation lever 412R has been operated, and outputs this detection signal to the ECU 10.
  • the pilot pump 54 discharges pilot pressure oil as a command input to the direction switching valve 53 (53a, 53b, 53c, 53d, 53e, 53f). In FIG. 4, a part of the oil passage between the pilot pump 54 and the direction switching valve 53 is omitted.
  • the remote control valve 55 is configured to be able to switch and adjust the direction of the pilot pressure oil input to the direction switching valve 53 in accordance with operations on the work operation levers 412L and 412R and the travel levers 413L and 413R.
  • the remote control valve 55 is provided for each hydraulic actuator and the corresponding direction switching valve 53.
  • a first hydraulic actuator remote control valve 55a corresponding to a work operation lever 412R for expanding and contracting the first hydraulic actuator 121 is provided.
  • the direction of the pilot pressure oil as a command to be supplied to the first hydraulic actuator direction switching valve 53a is switched.
  • a left travel motor remote control valve 55b corresponding to a travel lever 413L for rotating the left travel motor 22L is provided, and the left travel motor remote control valve 55b is supplied to the left travel motor direction switching valve 53c. Change the direction of pilot pressure oil as a command to perform.
  • a right travel motor remote control valve 55c corresponding to a travel lever 413R for rotating the right travel motor 22R is provided, and the right travel motor remote control valve 55c is directed to the right travel motor direction switching valve 53d. Switch the direction of pilot pressure oil as a command to supply.
  • remote control valves 55 corresponding to the other direction switching valves 53b, 53e, and 53f are provided.
  • an electromagnetic pressure reducing valve 19 is provided in the oil passage between the first hydraulic actuator remote control valve 55a and the pilot pump 54.
  • the electromagnetic pressure reducing valve 19 can control the primary pressure of the pilot pressure oil discharged from the pilot pump 14 and supplied to the first hydraulic actuator remote control valve 55a.
  • the hydraulic circuit 5 includes an ECU 10 that transmits a control command to the electromagnetic pressure reducing valve 19.
  • ECU10 transmits a control command according to operation of work operation levers 412L and 412R and travel levers 413L and 413R.
  • the hydraulic circuit 5 includes a merging switching valve 56.
  • the junction switching valve 56 is a pilot-type direction switching valve capable of joining the pressure oil discharged from the first hydraulic pump 51 and the second hydraulic pump 52.
  • the merging switching valve 56 can be switched to the position 56X or the position 56Y by sliding the spool.
  • pilot pressure is applied to the pilot port 56a and the pilot port 56b of the merging switching valve 56
  • the merging switching valve 56 is switched to the position 56Y.
  • pilot pressure is not applied to the pilot port 56a or the pilot port 56b of the merging switching valve 56, the merging switching valve 56 is held at the position 56X by the biasing force of the spring.
  • An oil path from the right travel motor remote control valve 55c is connected to the pilot port 56a, and an oil path from the left travel motor remote control valve 55b is connected to the pilot port 56b.
  • the pressure oil discharged from the first hydraulic pump 51 and the second hydraulic pump 52 flows separately without being merged, and the pressure oil discharged from the first hydraulic pump 51 is
  • the pressure oil supplied to the right travel motor direction switching valve 53d, the third hydraulic actuator direction switching valve 53e, and the turning direction switching valve 53f and discharged from the second hydraulic pump 52 is used for the first hydraulic actuator. It is supplied to the direction switching valve 53a, the second hydraulic actuator direction switching valve 53b, and the left travel motor direction switching valve 53c.
  • the ECU 10 reduces the primary pressure of the pilot pressure oil from the reference pressure to the first command pressure with respect to the electromagnetic pressure reducing valve 19, and the traveling levers 413L and 413R are operated. During this time, a first command for holding the primary pressure of the pilot pressure oil at the first command pressure is transmitted to the electromagnetic pressure reducing valve 19.
  • the ECU 10 changes the primary pressure of the pilot pressure oil from the first command pressure to the second command to the electromagnetic pressure reducing valve 19.
  • a second command for gradually increasing the pressure is transmitted.
  • a command for holding the primary pressure of the pilot pressure oil at the second command pressure is transmitted to the electromagnetic pressure reducing valve 19.
  • the hydraulic oil 51 and the second hydraulic pump 52 are not suddenly supplied to the first hydraulic actuator 121, and the traveling speed is suddenly reduced due to the rapid decrease in the amount of hydraulic oil supplied to the traveling motors 22L and 22R. Can be prevented.
  • the pressure oil discharged from the first hydraulic pump 51 and the second hydraulic pump 52 is merged by the merging switching valve 56 during traveling, so that the oil of the pressure oil supplied to the traveling motors 22L and 22R. A sudden drop in the amount can be effectively prevented.
  • the ECU 10 sets the primary pressure of the pilot pressure oil to the first command pressure from the second command pressure to the electromagnetic pressure reducing valve 19. A command to gradually decrease to the command pressure is transmitted. Thereafter, while only the travel levers 413L and 413R are being operated, a command for holding the primary pressure of the pilot pressure oil at the first command pressure is transmitted to the electromagnetic pressure reducing valve 19.
  • the ECU 10 sends a command to the electromagnetic pressure reducing valve 19 to increase the primary pressure from the pilot pump 54 from the first command value to the reference value and hold it.
  • control of the present invention can be applied to a plurality of actuators corresponding to a plurality of operation devices by simply installing branch paths that reach the plurality of operation devices downstream of the electromagnetic pressure reducing valve 19.
  • a plurality of electromagnetic proportional valves for controlling the secondary pressure of the operating device is unnecessary, and a hydraulic circuit can be provided with an inexpensive configuration.

Abstract

A hydraulic circuit (100) is provided with: a first actuator (11); a second actuator (12); a hydraulic pump (13); a first direction switching valve (15); a second direction switching valve (16); a pilot pump (14); a first operation device (17); a second operation device (18); an electromagnetic pressure reduction valve (19) that controls the primary pressure of pilot hydraulic oil supplied to the second operation device (18); and an ECU (10). The ECU (10) issues, to the electromagnetic pressure reduction valve (19), a first command for lowering the primary pressure from a reference pressure to a first command pressure and holds the primary pressure while the first operation device (17) is operated, and issues, to the electromagnetic pressure reduction valve (19), a second command for gradually increasing the primary pressure from the first command pressure to a second command pressure when the second operation device (18) is operated from the state where the first operation device (17) is operated.

Description

作業車両の油圧回路Hydraulic circuit of work vehicle
　本発明は、作業車両の油圧回路に関する。 The present invention relates to a hydraulic circuit for a work vehicle.
　下記特許文献１には、走行用アクチュエータを含む複数の油圧アクチュエータを駆動するための油圧制御回路を備える建設機械において、走行用アクチュエータの単独動作から走行用アクチュエータと別のアクチュエータとの複合動作への移行時に油圧ポンプから走行用アクチュエータに供給される圧油の流量の低下による走行速度の急激な低下を防止する技術として、走行用アクチュエータが動作している状態で別のアクチュエータとの複合動作を行う時に、流量制御弁により、方向切換弁の戻り側のパイロット圧受圧部に作用するパイロット圧油の戻り油を絞ることで、方向切換弁の入り側のパイロット圧受圧部にパイロット圧が作用した際、スプールの開放速度を遅らせ、別のアクチュエータの圧油量をなだらかに増加させることにより、走行用アクチュエータに供給される圧油の流量の急激な低下を防止する技術が開示されている。 In Patent Document 1 below, in a construction machine including a hydraulic control circuit for driving a plurality of hydraulic actuators including a traveling actuator, a single operation of the traveling actuator is changed to a combined operation of the traveling actuator and another actuator. As a technology to prevent a sudden decrease in travel speed due to a decrease in the flow rate of pressure oil supplied from the hydraulic pump to the travel actuator during transition, a combined operation with another actuator is performed while the travel actuator is operating When the pilot pressure is applied to the pilot pressure receiving part on the inlet side of the direction switching valve by reducing the return pressure of the pilot pressure oil acting on the pilot pressure receiving part on the return side of the direction switching valve. , To slow the opening speed of the spool and to gently increase the pressure oil amount of another actuator Ri, a technique for preventing discloses a sharp reduction of the flow rate of the hydraulic fluid supplied to the traveling actuator.
　下記特許文献２には、急操作時の緩衝作用を確保しながら、操作性悪化等の弊害を防止する技術として、操作量に応じた２次圧をパイロット圧としてコントロールバルブのパイロットポートに導くパイロットラインに供給する減圧弁と、この減圧弁の１次圧源としてのパイロット油圧源とを備えた建設機械の油圧回路において、減圧弁の１次側に、第１絞りと、パイロットラインをタンクに連通させるブリードオフラインを設け、ブリードオフラインに第２絞りを設置する技術が開示されている。 In Patent Document 2 below, as a technique for preventing adverse effects such as deterioration in operability while securing a buffering action during sudden operation, a pilot that guides a secondary pressure corresponding to an operation amount to a pilot port of a control valve as a pilot pressure. In a hydraulic circuit of a construction machine having a pressure reducing valve to be supplied to a line and a pilot hydraulic power source as a primary pressure source of the pressure reducing valve, a first throttle and a pilot line are connected to a tank on the primary side of the pressure reducing valve. A technique for providing a bleed offline for communication and installing a second aperture in the bleed offline is disclosed.
特開２００５－１２１１５５号公報JP 2005-121155 A 特開２００６－１２５６２７号公報JP 2006-125627 A
　しかしながら、特許文献１では、方向切換弁の戻り側のパイロット圧受圧部に作用するパイロット圧油の戻り油路に流量制御弁を設置して戻り油を絞るため、複合動作時に流量を制御したいアクチュエータを制御するリモコン弁ごとに流量制御弁を設置する必要がありコストが上昇するという問題がある。また、特許文献２では、パイロット圧の絶対値を抑えるための、第１絞りを減圧弁の１次側に配置していることから、方向切換弁の受圧部ごとにパイロット圧油を絞るための手段を配置する必要がないが、パイロット圧の立ち上がりを緩やかにするための第２絞りを備えるブリードオフラインを減圧弁の２次側に配置しているため、ブリードオフラインを方向切換弁の受圧部ごとに配置する必要があることからコストが上昇するという問題がある。 However, in Patent Document 1, the flow control valve is installed in the return oil path of the pilot pressure oil that acts on the pilot pressure receiving portion on the return side of the direction switching valve to throttle the return oil. Therefore, it is necessary to install a flow rate control valve for each remote control valve that controls the operation, which increases the cost. Further, in Patent Document 2, since the first throttle for suppressing the absolute value of the pilot pressure is arranged on the primary side of the pressure reducing valve, the pilot pressure oil is throttled for each pressure receiving portion of the direction switching valve. There is no need to arrange the means, but since the bleed offline having the second throttle for gradual rise of the pilot pressure is arranged on the secondary side of the pressure reducing valve, the bleed offline is arranged for each pressure receiving part of the direction switching valve. There is a problem that the cost rises because it is necessary to arrange in the.
　そこで、本発明は上記課題に鑑み、複数の油圧アクチュエータを備える作業車両において、一つの油圧アクチュエータを駆動する単独動作から、複数の油圧アクチュエータを駆動する複合動作に移行する際に発生する油量の急激な低下によるショックを防止することができる作業車両の油圧回路を安価な構成にて提供することを目的とする。 Therefore, in view of the above-described problems, the present invention provides a method for reducing the amount of oil generated when shifting from a single operation for driving a single hydraulic actuator to a combined operation for driving a plurality of hydraulic actuators in a work vehicle including a plurality of hydraulic actuators. An object of the present invention is to provide a hydraulic circuit of a work vehicle that can prevent a shock due to a sudden drop with an inexpensive configuration.
　本発明の作業車両の油圧回路は、第１アクチュエータと、第２アクチュエータと、前記第１アクチュエータ及び前記第２アクチュエータに圧油を供給する油圧ポンプと、前記第１アクチュエータに供給される圧油の向きを切り換え流量を調節する第１方向切換弁と、前記第２アクチュエータに供給される圧油の向きを切り換え流量を調節する第２方向切換弁と、前記第１方向切換弁及び前記第２方向切換弁にパイロット圧油を供給するパイロットポンプと、前記第１方向切換弁に供給されるパイロット圧油の向きと圧力を操作に応じて切り換え調節可能な第１操作装置と、前記第２方向切換弁に供給されるパイロット圧油の向きと圧力を操作に応じて切り換え調節可能な第２操作装置と、前記第２操作装置と前記パイロットポンプとの間の油路に設けられ、前記第２操作装置に供給されるパイロット圧油の１次圧力を制御する圧力制御装置と、前記圧力制御装置に制御指令を発信する制御指令発信装置と、を備え、
　前記制御指令発信装置は、前記第１操作装置が操作されている間は、前記圧力制御装置に対して前記１次圧力を基準圧から第１指令圧に減圧して保持する第１指令を発信し、
　前記第１操作装置が操作された状態から前記第２操作装置が操作されると、前記圧力制御装置に対して前記１次圧力を前記第１指令圧から第２指令圧に漸増させる第２指令を発信するものである。 A hydraulic circuit for a work vehicle according to the present invention includes a first actuator, a second actuator, a hydraulic pump that supplies pressure oil to the first actuator and the second actuator, and pressure oil that is supplied to the first actuator. A first direction switching valve for switching the direction and adjusting the flow rate; a second direction switching valve for switching the direction of the pressure oil supplied to the second actuator; and the first direction switching valve and the second direction. A pilot pump for supplying pilot pressure oil to the switching valve; a first operating device capable of switching and adjusting the direction and pressure of the pilot pressure oil supplied to the first direction switching valve according to an operation; and the second direction switching. A second operating device capable of switching and adjusting a direction and pressure of pilot pressure oil supplied to the valve according to an operation; and an oil between the second operating device and the pilot pump. Provided, comprising a pressure controller for controlling the primary pressure of the pilot pressure oil supplied to the second operating unit, and a control command transmitter which transmits a control command to the pressure control device,
The control command transmission device transmits a first command for reducing and holding the primary pressure from a reference pressure to a first command pressure to the pressure control device while the first operation device is being operated. And
When the second operating device is operated from the state where the first operating device is operated, a second command for gradually increasing the primary pressure from the first command pressure to the second command pressure with respect to the pressure control device. Is to send.
　本発明において、前記制御指令発信装置は、前記第１操作装置が操作された状態のまま前記第２操作装置が操作されなくなると、前記圧力制御装置に対して前記１次圧力を前記第２指令圧から前記第１指令圧に漸減させる指令を発信するものでもよい。 In the present invention, when the second operating device is not operated while the first operating device is operated, the control command transmission device sends the primary pressure to the pressure control device when the second command is not operated. A command for gradually decreasing the pressure to the first command pressure may be transmitted.
　本発明において、前記第１アクチュエータは第１走行用油圧モータであり、前記第２アクチュエータは作業用油圧アクチュエータであってもよい。 In the present invention, the first actuator may be a first traveling hydraulic motor, and the second actuator may be a working hydraulic actuator.
　本発明において、前記第１走行用油圧モータ及び前記第１走行用油圧モータに圧油を供給する第１油圧ポンプを含む第１回路系統と、前記作業用油圧アクチュエータ、第２走行用油圧モータ、並びに前記作業用油圧アクチュエータ及び前記第２走行用油圧モータに圧油を供給する第２油圧ポンプを含む第２回路系統と、前記第１回路系統の圧油と前記第２回路系統の圧油を合流させる合流切換弁と、を備えるものでもよい。 In the present invention, a first circuit system including a first hydraulic pump for supplying pressure oil to the first traveling hydraulic motor and the first traveling hydraulic motor, the working hydraulic actuator, a second traveling hydraulic motor, And a second circuit system including a second hydraulic pump that supplies pressure oil to the working hydraulic actuator and the second traveling hydraulic motor, and pressure oil of the first circuit system and pressure oil of the second circuit system. And a merging switching valve for merging.
　本発明によれば、第１アクチュエータのみを駆動する単独動作から、第１アクチュエータと第２アクチュエータを同時に駆動する複合動作に移行する際、第２アクチュエータに対応する第２操作装置に供給されるパイロット圧油の圧力を第１指令圧から第２指令圧に漸増させるため、第１アクチュエータに供給される圧油の油量の急激な低下によるショックを防止することができる。また、圧力制御装置の下流側に複数の操作装置に至る分岐路を設置するだけで、複数のアクチュエータに本発明の制御を入れることができるため、油圧回路を安価な構成にて提供することができる。 According to the present invention, when shifting from a single operation for driving only the first actuator to a combined operation for simultaneously driving the first actuator and the second actuator, the pilot supplied to the second operating device corresponding to the second actuator. Since the pressure oil pressure is gradually increased from the first command pressure to the second command pressure, it is possible to prevent a shock due to a rapid decrease in the amount of pressure oil supplied to the first actuator. In addition, since the control of the present invention can be applied to a plurality of actuators simply by installing a branch path to a plurality of operation devices on the downstream side of the pressure control device, it is possible to provide a hydraulic circuit with an inexpensive configuration. it can.
第１実施形態に係る作業車両の油圧回路を示す図である。It is a figure which shows the hydraulic circuit of the working vehicle which concerns on 1st Embodiment. 第２リモコン弁に供給されるパイロット圧油の１次圧力を制御する様子を示す図である。It is a figure which shows a mode that the primary pressure of the pilot pressure oil supplied to a 2nd remote control valve is controlled. 第２実施形態に係る作業車両を示す側面図である。It is a side view which shows the work vehicle which concerns on 2nd Embodiment. 第２実施形態に係る作業車両の油圧回路を示す図である。It is a figure which shows the hydraulic circuit of the working vehicle which concerns on 2nd Embodiment.
　以下に、本発明の実施形態について図面を参照しながら説明する。 Hereinafter, embodiments of the present invention will be described with reference to the drawings.
　＜第１実施形態＞
　図１は、第１実施形態に係る油圧回路１００を示している。油圧回路１００は、第１アクチュエータ１１と、第２アクチュエータ１２と、油圧ポンプ１３と、パイロットポンプ１４と、第１方向切換弁１５と、第２方向切換弁１６と、第１操作装置１７と、第２操作装置１８と、を備えている。 <First Embodiment>
FIG. 1 shows a hydraulic circuit 100 according to the first embodiment. The hydraulic circuit 100 includes a first actuator 11, a second actuator 12, a hydraulic pump 13, a pilot pump 14, a first direction switching valve 15, a second direction switching valve 16, a first operating device 17, A second operating device 18.
　第１アクチュエータ１１は、油圧ポンプ１３から供給された圧油により駆動される油圧モータである。第２アクチュエータ１２は、油圧ポンプ１３から供給された圧油により駆動される油圧シリンダである。ただし、第１アクチュエータ１１は油圧シリンダでもよく、また、第２アクチュエータ１２は油圧モータでもよい。 The first actuator 11 is a hydraulic motor that is driven by pressure oil supplied from the hydraulic pump 13. The second actuator 12 is a hydraulic cylinder driven by the pressure oil supplied from the hydraulic pump 13. However, the first actuator 11 may be a hydraulic cylinder, and the second actuator 12 may be a hydraulic motor.
　油圧ポンプ１３は、不図示のエンジンによって駆動され、圧油を吐出する。油圧ポンプ１３から吐出された圧油は、油路１３ａ、油路１３ｂを介して第１方向切換弁１５及び第２方向切換弁１６へと供給される。なお、図１では、油圧ポンプ１３から第１アクチュエータ１１及び第２アクチュエータ１２に供給される圧油の油路を実線で示している。 The hydraulic pump 13 is driven by an engine (not shown) and discharges pressure oil. The pressure oil discharged from the hydraulic pump 13 is supplied to the first direction switching valve 15 and the second direction switching valve 16 through the oil passage 13a and the oil passage 13b. In FIG. 1, the oil passage of the pressure oil supplied from the hydraulic pump 13 to the first actuator 11 and the second actuator 12 is indicated by a solid line.
　第１方向切換弁１５は、第１アクチュエータ１１に供給される圧油の向きを切り換え流量を調節することが可能なパイロット式の方向切換弁である。第２方向切換弁１６は、第２アクチュエータ１２に供給される圧油の向きを切り換え流量を調節することが可能なパイロット式の方向切換弁である。 The first direction switching valve 15 is a pilot-type direction switching valve capable of switching the direction of the pressure oil supplied to the first actuator 11 and adjusting the flow rate. The second direction switching valve 16 is a pilot-type direction switching valve capable of switching the direction of the pressure oil supplied to the second actuator 12 and adjusting the flow rate.
　パイロットポンプ１４は、第１方向切換弁１５及び第２方向切換弁１６へ入力される指令としてのパイロット圧油を吐出する。なお、図１では、パイロットポンプ１４から第１方向切換弁１５及び第２方向切換弁１６に供給されるパイロット圧油の油路を破線で示している。パイロットポンプ１４は、第１方向切換弁１５及び第２方向切換弁１６に付与されるパイロット圧を発生させる。パイロットポンプ１４は、不図示のエンジンによって駆動され、圧油を吐出することにより、油路１４ａ内にパイロット圧を発生させる。油路１４ａは、油路１４ｂ，１４ｃ，１４ｄ，１４ｅに分岐されている。 The pilot pump 14 discharges pilot pressure oil as a command input to the first direction switching valve 15 and the second direction switching valve 16. In FIG. 1, the oil passage of pilot pressure oil supplied from the pilot pump 14 to the first directional switching valve 15 and the second directional switching valve 16 is indicated by broken lines. The pilot pump 14 generates a pilot pressure applied to the first directional switching valve 15 and the second directional switching valve 16. The pilot pump 14 is driven by an engine (not shown) and generates a pilot pressure in the oil passage 14a by discharging pressure oil. The oil passage 14a is branched into oil passages 14b, 14c, 14d, and 14e.
　第１方向切換弁１５は、スプールを摺動させることにより複数のポジションに切り換えることが可能である。第１方向切換弁１５のパイロットポート１５ａ及びパイロットポート１５ｂのいずれにもパイロット圧が付与されない場合、スプリングの付勢力により、第１方向切換弁１５は中立位置に保持される。第１方向切換弁１５が中立位置にある場合、圧油は、油路１３ｂから第１アクチュエータ１１に供給されない。 The first direction switching valve 15 can be switched to a plurality of positions by sliding the spool. When pilot pressure is not applied to either the pilot port 15a or the pilot port 15b of the first direction switching valve 15, the first direction switching valve 15 is held in the neutral position by the biasing force of the spring. When the 1st direction switching valve 15 exists in a neutral position, pressure oil is not supplied to the 1st actuator 11 from the oil path 13b.
　一方、第１方向切換弁１５のパイロットポート１５ａ又はパイロットポート１５ｂにパイロット圧が付与された場合、第１方向切換弁１５が中立位置から他のポジションに切り換えられて、圧油は、油路１１ａ又は油路１１ｂを介して第１アクチュエータ１１に供給される。油路１１ａ又は油路１１ｂを介して供給される圧油によって、第１アクチュエータ１１は正方向又は逆方向に回転駆動する。 On the other hand, when a pilot pressure is applied to the pilot port 15a or the pilot port 15b of the first directional switching valve 15, the first directional switching valve 15 is switched from the neutral position to another position, and the pressure oil flows through the oil passage 11a. Alternatively, it is supplied to the first actuator 11 through the oil passage 11b. The first actuator 11 is driven to rotate in the forward direction or the reverse direction by the pressure oil supplied via the oil passage 11a or the oil passage 11b.
　第２方向切換弁１６は、スプールを摺動させることにより複数のポジションに切り換えることが可能である。第２方向切換弁１６のパイロットポート１６ａ及びパイロットポート１６ｂのいずれにもパイロット圧が付与されない場合、スプリングの付勢力により、第２方向切換弁１６は中立位置に保持される。第２方向切換弁１６が中立位置にある場合、圧油は、油路１３ａから第２アクチュエータ１２に供給されない。 The second direction switching valve 16 can be switched to a plurality of positions by sliding the spool. When pilot pressure is not applied to either the pilot port 16a or the pilot port 16b of the second direction switching valve 16, the second direction switching valve 16 is held in the neutral position by the biasing force of the spring. When the second direction switching valve 16 is in the neutral position, the pressure oil is not supplied to the second actuator 12 from the oil passage 13a.
　一方、第２方向切換弁１６のパイロットポート１６ａ又はパイロットポート１６ｂにパイロット圧が付与された場合、第２方向切換弁１６が中立位置から他のポジションに切り換えられて、圧油は、油路１２ａ又は油路１２ｂを介して第２アクチュエータ１２に供給される。油路１２ａ又は油路１２ｂを介して供給される圧油によって、第２アクチュエータ１２は伸縮する。 On the other hand, when the pilot pressure is applied to the pilot port 16a or the pilot port 16b of the second direction switching valve 16, the second direction switching valve 16 is switched from the neutral position to another position, and the pressure oil is supplied to the oil passage 12a. Or it is supplied to the second actuator 12 via the oil passage 12b. The second actuator 12 expands and contracts by the pressure oil supplied through the oil passage 12a or the oil passage 12b.
　第１方向切換弁１５には、第１検出用方向切換弁１５ｃが内装されている。第１検出用方向切換弁１５ｃは、スプールを摺動させることにより複数のポジションに切り換えることが可能である。第１方向切換弁１５が中立位置に保持されている場合、第１検出用方向切換弁１５ｃも中立位置に保持される。第１方向切換弁１５が中立位置から他のポジションに切り換えられた場合、これに連動して第１検出用方向切換弁１５ｃも中立位置から他のポジションに切り換えられる。 The first direction switching valve 15 is provided with a first detection direction switching valve 15c. The first detection direction switching valve 15c can be switched to a plurality of positions by sliding the spool. When the first direction switching valve 15 is held at the neutral position, the first detection direction switching valve 15c is also held at the neutral position. When the first direction switching valve 15 is switched from the neutral position to another position, the first detection direction switching valve 15c is also switched from the neutral position to another position in conjunction with this.
　第１検出用方向切換弁１５ｃが中立位置にある場合、第１検出用方向切換弁１５ｃは、油路１４ｂを閉塞することがない。そのため、圧油は、油路１４ｂを第１検出用方向切換弁１５ｃを介して流通することができる。一方、第１検出用方向切換弁１５ｃが中立位置以外のポジションにある場合、第１検出用方向切換弁１５ｃは、油路１４ｂを閉塞する。 When the first detection direction switching valve 15c is in the neutral position, the first detection direction switching valve 15c does not block the oil passage 14b. Therefore, the pressure oil can flow through the oil passage 14b via the first detection direction switching valve 15c. On the other hand, when the first detection direction switching valve 15c is in a position other than the neutral position, the first detection direction switching valve 15c closes the oil passage 14b.
　油路１４ｂには、第１圧力スイッチ１４１が接続されている。第１操作装置１７が操作され、第１検出用方向切換弁１５ｃが中立位置から中立位置以外のポジションとなることにより、油路１４ｂが閉塞されて油路１４ｂの絞り下流部に圧が立ち、この圧が第１圧力スイッチ１４１によって検出されるように構成されている。第１圧力スイッチ１４１は、第１操作装置１７が操作されたことを検出し、この検出信号を後述のＥＣＵ１０に出力する。 A first pressure switch 141 is connected to the oil passage 14b. When the first operating device 17 is operated and the first detection direction switching valve 15c is changed from the neutral position to a position other than the neutral position, the oil passage 14b is closed and pressure is generated in the throttle downstream portion of the oil passage 14b. This pressure is configured to be detected by the first pressure switch 141. The first pressure switch 141 detects that the first operating device 17 has been operated, and outputs this detection signal to the ECU 10 described later.
　第２方向切換弁１６には、第２検出用方向切換弁１６ｃが内装されている。第２検出用方向切換弁１６ｃは、スプールを摺動させることにより複数のポジションに切り換えることが可能である。第２方向切換弁１６が中立位置に保持されている場合、第２検出用方向切換弁１６ｃも中立位置に保持される。第２方向切換弁１６が中立位置から他のポジションに切り換えられた場合、これに連動して第２検出用方向切換弁１６ｃも中立位置から他のポジションに切り換えられる。 The second direction switching valve 16 includes a second detection direction switching valve 16c. The second detection direction switching valve 16c can be switched to a plurality of positions by sliding the spool. When the second direction switching valve 16 is held at the neutral position, the second detection direction switching valve 16c is also held at the neutral position. When the second direction switching valve 16 is switched from the neutral position to another position, the second detection direction switching valve 16c is also switched from the neutral position to another position in conjunction with this.
　第２検出用方向切換弁１６ｃが中立位置にある場合、第２検出用方向切換弁１６ｃは、油路１４ｃを閉塞することがない。そのため、圧油は、油路１４ｃを第２検出用方向切換弁１６ｃを介して流通することができる。一方、第２検出用方向切換弁１６ｃが中立位置以外のポジションにある場合、第２検出用方向切換弁１６ｃは、油路１４ｃを閉塞する。 When the second detection direction switching valve 16c is in the neutral position, the second detection direction switching valve 16c does not block the oil passage 14c. Therefore, the pressure oil can flow through the oil passage 14c via the second detection direction switching valve 16c. On the other hand, when the second detection direction switching valve 16c is in a position other than the neutral position, the second detection direction switching valve 16c closes the oil passage 14c.
　油路１４ｃには、第２圧力スイッチ１４２が接続されている。第２操作装置１８が操作され、第２検出用方向切換弁１６ｃが中立位置から中立位置以外のポジションとなることにより、油路１４ｃが閉塞されて油路１４ｃの絞り下流部に圧が立ち、この圧が第２圧力スイッチ１４２によって検出されるように構成されている。第２圧力スイッチ１４２は、第２操作装置１８が操作されたことを検出し、この検出信号を後述のＥＣＵ１０に出力する。 A second pressure switch 142 is connected to the oil passage 14c. When the second operating device 18 is operated and the second detection direction switching valve 16c is changed from the neutral position to a position other than the neutral position, the oil passage 14c is closed and pressure is generated in the throttle downstream portion of the oil passage 14c. This pressure is configured to be detected by the second pressure switch 142. The second pressure switch 142 detects that the second operating device 18 has been operated, and outputs this detection signal to the ECU 10 described later.
　第１操作装置１７は、第１方向切換弁１５に供給されるパイロット圧油の向きと圧力を切り換えるための第１リモコン弁１７０を有する。第１リモコン弁１７０は、油路１４ｄに接続される。また、第１リモコン弁１７０は、油路１７ａ及び油路１７ｂを介して第１方向切換弁１５のパイロットポート１５ａ及びパイロットポート１５ｂにそれぞれ接続される。第１リモコン弁１７０は、油路１４ｄを介してパイロットポンプ１４から供給される圧油を、パイロット用の圧油として第１方向切換弁１５に供給する。第１操作装置１７を操作することにより、第１方向切換弁１５を切り換え、第１アクチュエータ１１に供給される圧油の向きを切り換え流量を調節することができる。 The first operating device 17 has a first remote control valve 170 for switching the direction and pressure of the pilot pressure oil supplied to the first direction switching valve 15. The first remote control valve 170 is connected to the oil passage 14d. The first remote control valve 170 is connected to the pilot port 15a and the pilot port 15b of the first direction switching valve 15 via the oil passage 17a and the oil passage 17b, respectively. The first remote control valve 170 supplies the pressure oil supplied from the pilot pump 14 via the oil passage 14d to the first direction switching valve 15 as pilot pressure oil. By operating the first operating device 17, the first direction switching valve 15 can be switched, the direction of the pressure oil supplied to the first actuator 11 can be switched, and the flow rate can be adjusted.
　第２操作装置１８は、第２方向切換弁１６に供給されるパイロット圧油の向きと圧力を切り換えるための第２リモコン弁１８０を有する。第２リモコン弁１８０は、油路１４ｅに接続される。また、第２リモコン弁１８０は、油路１８ａ及び油路１８ｂを介して第２方向切換弁１６のパイロットポート１６ａ及びパイロットポート１６ｂにそれぞれ接続される。第２リモコン弁１８０は、油路１４ｅを介してパイロットポンプ１４から供給される圧油を、パイロット用の圧油として第２方向切換弁１６に供給する。第２操作装置１８を操作することにより、第２方向切換弁１６を切り換え、第２アクチュエータ１２に供給される圧油の向きを切り換え流量を調節することができる。 The second operating device 18 has a second remote control valve 180 for switching the direction and pressure of the pilot pressure oil supplied to the second direction switching valve 16. The second remote control valve 180 is connected to the oil passage 14e. The second remote control valve 180 is connected to the pilot port 16a and the pilot port 16b of the second direction switching valve 16 via the oil passage 18a and the oil passage 18b, respectively. The second remote control valve 180 supplies the pressure oil supplied from the pilot pump 14 via the oil passage 14e to the second direction switching valve 16 as pilot pressure oil. By operating the second operating device 18, the second direction switching valve 16 can be switched and the direction of the pressure oil supplied to the second actuator 12 can be switched to adjust the flow rate.
　第２リモコン弁１８０とパイロットポンプ１４との間の油路１４ｅには、電磁式減圧弁１９（圧力制御装置の一例）が設けられている。電磁式減圧弁１９は、パイロットポンプ１４から吐出されて第２リモコン弁１８０に供給されるパイロット圧油の１次圧力を制御することができる。電磁式減圧弁１９は、入力される電流の大きさに応じて圧力を制御することができる。 In the oil passage 14e between the second remote control valve 180 and the pilot pump 14, an electromagnetic pressure reducing valve 19 (an example of a pressure control device) is provided. The electromagnetic pressure reducing valve 19 can control the primary pressure of the pilot pressure oil discharged from the pilot pump 14 and supplied to the second remote control valve 180. The electromagnetic pressure reducing valve 19 can control the pressure according to the magnitude of the input current.
　油圧回路１００は、電磁式減圧弁１９に制御指令を発信するＥＣＵ１０（制御指令発信装置の一例）を備えている。ＥＣＵ１０は、第１操作装置１７及び第２操作装置１８の操作に応じて制御指令を発信する。ＥＣＵ１０は、第１圧力スイッチ１４１からの検出信号を受信することで第１操作装置１７が操作されていると判定し、第２圧力スイッチ１４２からの検出信号を受信することで第２操作装置１８が操作されていると判定することができる。 The hydraulic circuit 100 includes an ECU 10 (an example of a control command transmission device) that transmits a control command to the electromagnetic pressure reducing valve 19. The ECU 10 issues a control command in accordance with the operation of the first operating device 17 and the second operating device 18. The ECU 10 determines that the first operating device 17 is operated by receiving a detection signal from the first pressure switch 141, and receives the detection signal from the second pressure switch 142 to receive the second operating device 18. Can be determined to be operated.
　次に、ＥＣＵ１０による電磁式減圧弁１９の制御について、図２を用いて説明する。図２は、第２リモコン弁１８０に供給されるパイロット圧油の１次圧力を制御する様子を示している。 Next, control of the electromagnetic pressure reducing valve 19 by the ECU 10 will be described with reference to FIG. FIG. 2 shows how the primary pressure of the pilot pressure oil supplied to the second remote control valve 180 is controlled.
　ＥＣＵ１０は、第１操作装置１７が操作されると（図２の時間Ａ）、電磁式減圧弁１９に対してパイロット圧油の１次圧力を基準圧から第１指令圧に減圧し、第１操作装置１７が操作されている間（図２の時間Ａ～Ｂ）は、電磁式減圧弁１９に対してパイロット圧油の１次圧力を第１指令圧に保持する第１指令を発信する。なお、基準圧とは、パイロットポンプ１４から吐出される圧油の圧力である。 When the first operating device 17 is operated (time A in FIG. 2), the ECU 10 reduces the primary pressure of the pilot pressure oil from the reference pressure to the first command pressure with respect to the electromagnetic pressure reducing valve 19, While the operating device 17 is being operated (time AB in FIG. 2), a first command for holding the primary pressure of the pilot pressure oil at the first command pressure is transmitted to the electromagnetic pressure reducing valve 19. The reference pressure is the pressure of the pressure oil discharged from the pilot pump 14.
　次いで、ＥＣＵ１０は、第１操作装置１７が操作された状態から第２操作装置１８が操作されると（図２の時間Ｂ）、電磁式減圧弁１９に対してパイロット圧油の１次圧力を第１指令圧から第２指令圧に漸増させる第２指令を発信する。第２指令圧は、第１指令圧よりも高く、基準圧よりも低い。基準圧、第１指令圧、第２指令圧の比率は適宜設定される。また、第１指令圧から第２指令圧に漸増させる時間（図２の時間Ｂ～Ｃ）も適宜設定される。 Next, when the second operating device 18 is operated from the state in which the first operating device 17 is operated (time B in FIG. 2), the ECU 10 applies the primary pressure of the pilot pressure oil to the electromagnetic pressure reducing valve 19. A second command for gradually increasing the first command pressure to the second command pressure is transmitted. The second command pressure is higher than the first command pressure and lower than the reference pressure. The ratio of the reference pressure, the first command pressure, and the second command pressure is set as appropriate. Further, the time for gradually increasing from the first command pressure to the second command pressure (time B to C in FIG. 2) is also set as appropriate.
　その後、第１操作装置１７及び第２操作装置１８が操作されている間（図２の時間Ｃ～Ｄ）は、電磁式減圧弁１９に対してパイロット圧油の１次圧力を第２指令圧に保持する指令を発信する。これにより、第１アクチュエータ１１のみを駆動する単独動作から、第１アクチュエータ１１と第２アクチュエータ１２を同時に駆動する複合動作に移行する際、第２リモコン弁１８０を介して第２方向切換弁１６に付与されるパイロット圧を第１指令圧から第２指令圧に漸増させるため、油圧ポンプ１３からの圧油が第２アクチュエータ１２に急激に供給されることがなく、第１アクチュエータ１１に供給される圧油の油量の急激な低下によるショックを防止することができる。 Thereafter, while the first operating device 17 and the second operating device 18 are operated (time C to D in FIG. 2), the primary pressure of the pilot pressure oil is set to the second command pressure with respect to the electromagnetic pressure reducing valve 19. Send the command to hold to. Accordingly, when the single operation for driving only the first actuator 11 is shifted to the combined operation for simultaneously driving the first actuator 11 and the second actuator 12, the second direction switching valve 16 is switched to the second direction switching valve 16 via the second remote control valve 180. In order to gradually increase the applied pilot pressure from the first command pressure to the second command pressure, the pressure oil from the hydraulic pump 13 is supplied to the first actuator 11 without being suddenly supplied to the second actuator 12. Shock due to a sudden drop in the amount of pressurized oil can be prevented.
　次いで、ＥＣＵ１０は、第１操作装置１７が操作された状態のまま第２操作装置１８が操作されなくなると（図２の時間Ｄ）、電磁式減圧弁１９に対してパイロット圧油の１次圧力を第２指令圧から第１指令圧に漸減させる指令を発信する。その後、第１操作装置１７のみが操作されている間（図２の時間Ｅ～Ｆ）は、電磁式減圧弁１９に対してパイロット圧油の１次圧力を第１指令圧に保持する指令を発信する。 Next, when the second operating device 18 is not operated while the first operating device 17 is operated (time D in FIG. 2), the ECU 10 applies the primary pressure of the pilot pressure oil to the electromagnetic pressure reducing valve 19. A command for gradually decreasing the pressure from the second command pressure to the first command pressure is transmitted. Thereafter, while only the first operating device 17 is being operated (time E to F in FIG. 2), a command for holding the primary pressure of the pilot pressure oil at the first command pressure is given to the electromagnetic pressure reducing valve 19. send.
　さらに、ＥＣＵ１０は、第１操作装置１７が操作されなくなると（図２の時間Ｆ）、電磁式減圧弁１９に対してパイロットポンプ１４からの１次圧力を第１指令値から基準値に増圧し保持する指令を発信する。 Further, when the first operating device 17 is not operated (time F in FIG. 2), the ECU 10 increases the primary pressure from the pilot pump 14 from the first command value to the reference value with respect to the electromagnetic pressure reducing valve 19. Send the command to hold.
　＜第２実施形態＞
　［作業車両の構造］
　まず、図３を参照しながら、作業車両の一例としての油圧ショベル１の概略構造について説明する。ただし、作業車両としては、油圧ショベル１に限定されず、ホイルローダ等の他の車両でもよい。油圧ショベル１は、走行装置２と、作業装置３と、旋回装置４とを備える。 Second Embodiment
[Work vehicle structure]
First, a schematic structure of a hydraulic excavator 1 as an example of a work vehicle will be described with reference to FIG. However, the work vehicle is not limited to the hydraulic excavator 1 and may be another vehicle such as a wheel loader. The excavator 1 includes a traveling device 2, a work device 3, and a turning device 4.
　走行装置２は、エンジン４２からの動力を受けて駆動し、油圧ショベル１を走行させる。走行装置２は、左右一対のクローラ２１，２１及び左右一対の走行モータ２２Ｌ，２２Ｒを備える。油圧モータである左右の走行モータ２２Ｌ，２２Ｒが左右のクローラ２１，２１をそれぞれ駆動することで油圧ショベル１の前後進を可能としている。また、走行装置２には、ブレード２３、及びブレード２３を上下方向に回動させるための油圧アクチュエータであるブレードシリンダ２４が設けられている。 The traveling device 2 is driven by receiving power from the engine 42 and causes the excavator 1 to travel. The traveling device 2 includes a pair of left and right crawlers 21 and 21 and a pair of left and right traveling motors 22L and 22R. The left and right traveling motors 22L and 22R, which are hydraulic motors, drive the left and right crawlers 21 and 21, respectively, so that the hydraulic excavator 1 can move forward and backward. Further, the traveling device 2 is provided with a blade 23 and a blade cylinder 24 that is a hydraulic actuator for rotating the blade 23 in the vertical direction.
　作業装置３は、エンジン４２からの動力を受けて駆動し、土砂等の掘削作業を行うものである。作業装置３は、ブーム３１、アーム３２、及びバケット３３を備え、これらを独立して駆動することによって掘削作業を可能としている。ブーム３１、アーム３２、及びバケット３３は、それぞれ作業部に相当し、油圧ショベル１は、複数の作業部を有する。 The working device 3 is driven by receiving power from the engine 42 and performs excavation work such as earth and sand. The working device 3 includes a boom 31, an arm 32, and a bucket 33, and enables them to perform excavation work by driving them independently. The boom 31, the arm 32, and the bucket 33 each correspond to a working unit, and the excavator 1 has a plurality of working units.
　ブーム３１は、一端部が旋回装置４の前部に支持されて、伸縮自在に可動するブームシリンダ３１ａによって回動される。また、アーム３２は、一端部がブーム３１の他端部に支持されて、伸縮自在に可動するアームシリンダ３２ａによって回動される。そして、バケット３３は、一端部がアーム３２の他端部に支持されて、伸縮自在に可動するバケットシリンダ３３ａによって回動される。ブームシリンダ３１ａ、アームシリンダ３２ａ、及びバケットシリンダ３３ａは、作業部を駆動する油圧アクチュエータに相当する。 The boom 31 is pivoted by a boom cylinder 31a, one end of which is supported by the front portion of the turning device 4 and movable in a telescopic manner. The arm 32 is supported by the other end of the boom 31 at one end and is rotated by an arm cylinder 32a that is movable in a telescopic manner. The bucket 33 is rotated by a bucket cylinder 33a that is supported at one end by the other end of the arm 32 and is movable in a telescopic manner. The boom cylinder 31a, the arm cylinder 32a, and the bucket cylinder 33a correspond to hydraulic actuators that drive the working unit.
　旋回装置４は、作業装置３を旋回させるものである。旋回装置４には、操縦部４１、エンジン４２、旋回台４３、旋回モータ４４等が配置されている。油圧モータである旋回モータ４４が旋回台４３を駆動することによって作業装置３を旋回させる。また、旋回装置４には、エンジン４２により駆動される複数の油圧ポンプ（図３に図示していない）が配設される。これらの油圧ポンプが、ブームシリンダ３１ａ、アームシリンダ３２ａ、及びバケットシリンダ３３ａ等に圧油を供給する。 The turning device 4 turns the work device 3. The turning device 4 includes a control unit 41, an engine 42, a turntable 43, a turn motor 44, and the like. A swing motor 44, which is a hydraulic motor, drives the swivel base 43 to swing the work device 3. The swing device 4 is provided with a plurality of hydraulic pumps (not shown in FIG. 3) driven by the engine 42. These hydraulic pumps supply pressure oil to the boom cylinder 31a, the arm cylinder 32a, the bucket cylinder 33a, and the like.
　操縦部４１には、操縦席４１１が配置されている。操縦席４１１の左右に一対の作業操作レバー４１２Ｌ，４１２Ｒ、前方に一対の走行レバー４１３Ｌ，４１３Ｒが配置されている。オペレータは、操縦席４１１に着座して作業操作レバー４１２Ｌ，４１２Ｒ、走行レバー４１３Ｌ，４１３Ｒ等を操作することによって、エンジン４２、各油圧モータ、各油圧アクチュエータ等の制御を行い、走行、旋回、作業等を行うことができる。 A pilot seat 411 is disposed in the pilot unit 41. A pair of work operation levers 412L and 412R are disposed on the left and right sides of the cockpit 411, and a pair of travel levers 413L and 413R are disposed on the front side. The operator sits on the cockpit 411 and operates the operation control levers 412L and 412R, the travel levers 413L and 413R, etc. to control the engine 42, each hydraulic motor, each hydraulic actuator, etc. Etc. can be performed.
　［油圧回路の構成］
　図４を用いて、油圧ショベル１が有する油圧回路５について説明する。油圧回路５は、第１～第３油圧アクチュエータ１２１，１２２，１２３（ブームシリンダ３１ａ、アームシリンダ３２ａ、バケットシリンダ３３ａ）、左走行モータ２２Ｌ、右走行モータ２２Ｒ、旋回モータ４４と、第１油圧ポンプ５１と、第２油圧ポンプ５２と、方向切換弁５３と、パイロットポンプ５４と、リモコン弁５５と、を有する。なお、図４では、説明の便宜のため、ブレードシリンダ２４等に関する回路を省略している。 [Configuration of hydraulic circuit]
A hydraulic circuit 5 included in the hydraulic excavator 1 will be described with reference to FIG. The hydraulic circuit 5 includes first to third hydraulic actuators 121, 122, 123 (boom cylinder 31a, arm cylinder 32a, bucket cylinder 33a), left traveling motor 22L, right traveling motor 22R, turning motor 44, and first hydraulic pump. 51, a second hydraulic pump 52, a direction switching valve 53, a pilot pump 54, and a remote control valve 55. In FIG. 4, for convenience of explanation, circuits relating to the blade cylinder 24 and the like are omitted.
　第２実施形態では、第１油圧ポンプ５１は、主に、右走行モータ２２Ｒ、第３油圧アクチュエータ１２３、及び旋回モータ４４に圧油を供給する。第２油圧ポンプ５２は、主に、第１油圧アクチュエータ１２１、第２油圧アクチュエータ１２２、及び左走行モータ２２Ｌに圧油を供給する。 In the second embodiment, the first hydraulic pump 51 mainly supplies pressure oil to the right traveling motor 22R, the third hydraulic actuator 123, and the turning motor 44. The second hydraulic pump 52 mainly supplies pressure oil to the first hydraulic actuator 121, the second hydraulic actuator 122, and the left traveling motor 22L.
　方向切換弁５３は、各々の油圧アクチュエータに対応して設けられており、第１油圧ポンプ５１及び第２油圧ポンプ５２から油圧アクチュエータへ供給される圧油の向き及び流量を切り換え可能に構成されている。複数の方向切換弁５３は、まとめてコントロールバルブと呼ばれる。具体的に、第２実施形態においては、第１油圧アクチュエータ１２１に対応する第１油圧アクチュエータ用方向切換弁５３ａと、第２油圧アクチュエータ１２２に対応する第２油圧アクチュエータ用方向切換弁５３ｂと、左走行モータ２２Ｌに対応する左走行モータ用方向切換弁５３ｃと、右走行モータ２２Ｒに対応する右走行モータ用方向切換弁５３ｄと、第３油圧アクチュエータ１２３に対応する第３油圧アクチュエータ用方向切換弁５３ｅと、旋回モータ４４に対応する旋回用方向切換弁５３ｆと、が設けられている。方向切換弁５３の構造は、第１実施形態の第１方向切換弁１５及び第２方向切換弁１６と同様のため、詳細な説明は省略する。 The direction switching valve 53 is provided corresponding to each hydraulic actuator, and is configured to be able to switch the direction and flow rate of the pressure oil supplied from the first hydraulic pump 51 and the second hydraulic pump 52 to the hydraulic actuator. Yes. The plurality of directional control valves 53 are collectively referred to as a control valve. Specifically, in the second embodiment, a first hydraulic actuator direction switching valve 53 a corresponding to the first hydraulic actuator 121, a second hydraulic actuator direction switching valve 53 b corresponding to the second hydraulic actuator 122, A left travel motor direction switching valve 53c corresponding to the travel motor 22L, a right travel motor direction switching valve 53d corresponding to the right travel motor 22R, and a third hydraulic actuator direction switching valve 53e corresponding to the third hydraulic actuator 123. And a turning direction switching valve 53 f corresponding to the turning motor 44. Since the structure of the direction switching valve 53 is the same as that of the first direction switching valve 15 and the second direction switching valve 16 of the first embodiment, detailed description thereof is omitted.
　方向切換弁５３には、検出用方向切換弁が内装されている。左走行モータ用方向切換弁５３ｃ及び右走行モータ用方向切換弁５３ｄにそれぞれ設けられた検出用方向切換弁は、パイロットポンプ５４からの油路５４ａを閉塞又は開放する。また、第１油圧アクチュエータ用方向切換弁５３ａ、第２油圧アクチュエータ用方向切換弁５３ｂ、第３油圧アクチュエータ用方向切換弁５３ｅ、及び旋回用方向切換弁５３ｆにそれぞれ設けられた検出用方向切換弁は、パイロットポンプ５４からの油路５４ｂを閉塞又は開放する。検出用方向切換弁の構造は、第１実施形態の第１検出用方向切換弁１５ｃ及び第２検出用方向切換弁１６ｃと同様のため、詳細な説明は省略する。 The direction switching valve 53 includes a detection direction switching valve. The detection direction switching valves provided in the left traveling motor direction switching valve 53c and the right traveling motor direction switching valve 53d respectively close or open the oil passage 54a from the pilot pump 54. In addition, the detection direction switching valves provided in the first hydraulic actuator direction switching valve 53a, the second hydraulic actuator direction switching valve 53b, the third hydraulic actuator direction switching valve 53e, and the turning direction switching valve 53f, respectively, Then, the oil passage 54b from the pilot pump 54 is closed or opened. Since the structure of the detection direction switching valve is the same as that of the first detection direction switching valve 15c and the second detection direction switching valve 16c of the first embodiment, detailed description thereof is omitted.
　油路５４ａには、第１圧力スイッチ１４１が接続されている。走行レバー４１３Ｌ，４１３Ｒが操作され、左走行モータ用方向切換弁５３ｃ又は右走行モータ用方向切換弁５３ｄの検出用方向切換弁が中立位置から中立位置以外のポジションとなることにより、油路５４ａが閉塞されて油路５４ａの絞り下流部に圧が立ち、この圧が第１圧力スイッチ１４１によって検出されるように構成されている。第１圧力スイッチ１４１は、走行レバー４１３Ｌ，４１３Ｒが操作されたことを検出し、この検出信号をＥＣＵ１０に出力する。 A first pressure switch 141 is connected to the oil passage 54a. When the travel levers 413L and 413R are operated and the detection direction switching valve of the left traveling motor direction switching valve 53c or the right traveling motor direction switching valve 53d is changed from the neutral position to a position other than the neutral position, the oil passage 54a is formed. The first pressure switch 141 detects the pressure that is closed and a pressure is generated in the downstream portion of the throttle of the oil passage 54a. The first pressure switch 141 detects that the travel levers 413L and 413R are operated, and outputs a detection signal to the ECU 10.
　油路５４ｂには、第２圧力スイッチ１４２が接続されている。作業操作レバー４１２Ｒが操作され、第１油圧アクチュエータ用方向切換弁５３ａの検出用方向切換弁が中立位置から中立位置以外のポジションとなることにより、油路５４ｂが閉塞されて油路５４ｂの絞り下流部に圧が立ち、この圧が第２圧力スイッチ１４２によって検出されるように構成されている。第２圧力スイッチ１４２は、作業操作レバー４１２Ｒが操作されたことを検出し、この検出信号をＥＣＵ１０に出力する。 A second pressure switch 142 is connected to the oil passage 54b. When the operation lever 412R is operated and the detection direction switching valve of the first hydraulic actuator direction switching valve 53a changes from the neutral position to a position other than the neutral position, the oil passage 54b is closed and the oil passage 54b is throttled downstream. A pressure is generated in the part, and this pressure is detected by the second pressure switch 142. The second pressure switch 142 detects that the work operation lever 412R has been operated, and outputs this detection signal to the ECU 10.
　パイロットポンプ５４は、方向切換弁５３（５３ａ，５３ｂ，５３ｃ，５３ｄ，５３ｅ，５３ｆ）へ入力される指令としてのパイロット圧油を吐出する。なお、図４では、パイロットポンプ５４と方向切換弁５３との間の油路は一部省略している。 The pilot pump 54 discharges pilot pressure oil as a command input to the direction switching valve 53 (53a, 53b, 53c, 53d, 53e, 53f). In FIG. 4, a part of the oil passage between the pilot pump 54 and the direction switching valve 53 is omitted.
　リモコン弁５５は、作業操作レバー４１２Ｌ，４１２Ｒ、走行レバー４１３Ｌ，４１３Ｒに対する操作に応じて方向切換弁５３に入力されるパイロット圧油の向きを切り換え調節可能に構成されている。リモコン弁５５は、各々の油圧アクチュエータ及び対応する方向切換弁５３毎に設けられている。例えば、図４に示すように、第１油圧アクチュエータ１２１を伸縮させるための作業操作レバー４１２Ｒに対応する第１油圧アクチュエータ用リモコン弁５５ａが設けられており、第１油圧アクチュエータ用リモコン弁５５ａは、第１油圧アクチュエータ用方向切換弁５３ａへ供給する指令としてのパイロット圧油の向きを切り換える。また、左走行モータ２２Ｌを回転させるための走行レバー４１３Ｌに対応する左走行モータ用リモコン弁５５ｂが設けられており、左走行モータ用リモコン弁５５ｂは、左走行モータ用方向切換弁５３ｃへと供給する指令としてのパイロット圧油の向きを切り換える。同様に、右走行モータ２２Ｒを回転させるための走行レバー４１３Ｒに対応する右走行モータ用リモコン弁５５ｃが設けられており、右走行モータ用リモコン弁５５ｃは、右走行モータ用方向切換弁５３ｄへと供給する指令としてのパイロット圧油の向きを切り換える。図４では図示していないが、その他の方向切換弁５３ｂ，５３ｅ，５３ｆに対応するリモコン弁５５が設けられている。 The remote control valve 55 is configured to be able to switch and adjust the direction of the pilot pressure oil input to the direction switching valve 53 in accordance with operations on the work operation levers 412L and 412R and the travel levers 413L and 413R. The remote control valve 55 is provided for each hydraulic actuator and the corresponding direction switching valve 53. For example, as shown in FIG. 4, a first hydraulic actuator remote control valve 55a corresponding to a work operation lever 412R for expanding and contracting the first hydraulic actuator 121 is provided. The direction of the pilot pressure oil as a command to be supplied to the first hydraulic actuator direction switching valve 53a is switched. Further, a left travel motor remote control valve 55b corresponding to a travel lever 413L for rotating the left travel motor 22L is provided, and the left travel motor remote control valve 55b is supplied to the left travel motor direction switching valve 53c. Change the direction of pilot pressure oil as a command to perform. Similarly, a right travel motor remote control valve 55c corresponding to a travel lever 413R for rotating the right travel motor 22R is provided, and the right travel motor remote control valve 55c is directed to the right travel motor direction switching valve 53d. Switch the direction of pilot pressure oil as a command to supply. Although not shown in FIG. 4, remote control valves 55 corresponding to the other direction switching valves 53b, 53e, and 53f are provided.
　第１油圧アクチュエータ用リモコン弁５５ａとパイロットポンプ５４との間の油路には、電磁式減圧弁１９が設けられている。電磁式減圧弁１９は、パイロットポンプ１４から吐出されて第１油圧アクチュエータ用リモコン弁５５ａに供給されるパイロット圧油の１次圧力を制御することができる。 In the oil passage between the first hydraulic actuator remote control valve 55a and the pilot pump 54, an electromagnetic pressure reducing valve 19 is provided. The electromagnetic pressure reducing valve 19 can control the primary pressure of the pilot pressure oil discharged from the pilot pump 14 and supplied to the first hydraulic actuator remote control valve 55a.
　油圧回路５は、電磁式減圧弁１９に制御指令を発信するＥＣＵ１０を備えている。ＥＣＵ１０は、作業操作レバー４１２Ｌ，４１２Ｒ、及び走行レバー４１３Ｌ，４１３Ｒの操作に応じて制御指令を発信する。 The hydraulic circuit 5 includes an ECU 10 that transmits a control command to the electromagnetic pressure reducing valve 19. ECU10 transmits a control command according to operation of work operation levers 412L and 412R and travel levers 413L and 413R.
　油圧回路５は、合流切換弁５６を備えている。合流切換弁５６は、第１油圧ポンプ５１及び第２油圧ポンプ５２から吐出された圧油を合流させることが可能なパイロット式の方向切換弁である。合流切換弁５６は、スプールを摺動させることによりポジション５６Ｘ又はポジション５６Ｙに切り換えることが可能である。合流切換弁５６のパイロットポート５６ａ及びパイロットポート５６ｂにパイロット圧が付与された場合、合流切換弁５６はポジション５６Ｙに切り換えられる。合流切換弁５６のパイロットポート５６ａ又はパイロットポート５６ｂにパイロット圧が付与されない場合、スプリングの付勢力により、合流切換弁５６はポジション５６Ｘに保持される。パイロットポート５６ａには、右走行モータ用リモコン弁５５ｃからの油路が接続され、パイロットポート５６ｂには、左走行モータ用リモコン弁５５ｂからの油路が接続されている。これにより、左右の走行レバー４１３Ｌ，４１３Ｒが同時に操作された際、すなわち走行操作をされた際、合流切換弁５６はポジション５６Ｙに切り換えられる。 The hydraulic circuit 5 includes a merging switching valve 56. The junction switching valve 56 is a pilot-type direction switching valve capable of joining the pressure oil discharged from the first hydraulic pump 51 and the second hydraulic pump 52. The merging switching valve 56 can be switched to the position 56X or the position 56Y by sliding the spool. When pilot pressure is applied to the pilot port 56a and the pilot port 56b of the merging switching valve 56, the merging switching valve 56 is switched to the position 56Y. When pilot pressure is not applied to the pilot port 56a or the pilot port 56b of the merging switching valve 56, the merging switching valve 56 is held at the position 56X by the biasing force of the spring. An oil path from the right travel motor remote control valve 55c is connected to the pilot port 56a, and an oil path from the left travel motor remote control valve 55b is connected to the pilot port 56b. Thereby, when the left and right traveling levers 413L and 413R are operated simultaneously, that is, when the traveling operation is performed, the merging switching valve 56 is switched to the position 56Y.
　合流切換弁５６がポジション５６Ｘにある場合、第１油圧ポンプ５１及び第２油圧ポンプ５２から吐出された圧油は合流されずに分かれて流れ、第１油圧ポンプ５１から吐出された圧油は、右走行モータ用方向切換弁５３ｄと、第３油圧アクチュエータ用方向切換弁５３ｅと、旋回用方向切換弁５３ｆとへ供給され、第２油圧ポンプ５２から吐出された圧油は、第１油圧アクチュエータ用方向切換弁５３ａと、第２油圧アクチュエータ用方向切換弁５３ｂと、左走行モータ用方向切換弁５３ｃとへ供給される。 When the merge switching valve 56 is at the position 56X, the pressure oil discharged from the first hydraulic pump 51 and the second hydraulic pump 52 flows separately without being merged, and the pressure oil discharged from the first hydraulic pump 51 is The pressure oil supplied to the right travel motor direction switching valve 53d, the third hydraulic actuator direction switching valve 53e, and the turning direction switching valve 53f and discharged from the second hydraulic pump 52 is used for the first hydraulic actuator. It is supplied to the direction switching valve 53a, the second hydraulic actuator direction switching valve 53b, and the left travel motor direction switching valve 53c.
　合流切換弁５６がポジション５６Ｙにある場合、第１油圧ポンプ５１及び第２油圧ポンプ５２から吐出された圧油は合流される。 When the merge switching valve 56 is in the position 56Y, the pressure oil discharged from the first hydraulic pump 51 and the second hydraulic pump 52 is merged.
　ＥＣＵ１０は、走行レバー４１３Ｌ，４１３Ｒが操作されると、電磁式減圧弁１９に対してパイロット圧油の１次圧力を基準圧から第１指令圧に減圧し、走行レバー４１３Ｌ，４１３Ｒが操作されている間は、電磁式減圧弁１９に対してパイロット圧油の１次圧力を第１指令圧に保持する第１指令を発信する。 When the traveling levers 413L and 413R are operated, the ECU 10 reduces the primary pressure of the pilot pressure oil from the reference pressure to the first command pressure with respect to the electromagnetic pressure reducing valve 19, and the traveling levers 413L and 413R are operated. During this time, a first command for holding the primary pressure of the pilot pressure oil at the first command pressure is transmitted to the electromagnetic pressure reducing valve 19.
　次いで、ＥＣＵ１０は、走行レバー４１３Ｌ，４１３Ｒが操作された状態から作業操作レバー４１２Ｒが操作されると、電磁式減圧弁１９に対してパイロット圧油の１次圧力を第１指令圧から第２指令圧に漸増させる第２指令を発信する。その後、走行レバー４１３Ｌ，４１３Ｒ及び作業操作レバー４１２Ｒが操作されている間は、電磁式減圧弁１９に対してパイロット圧油の１次圧力を第２指令圧に保持する指令を発信する。これにより、走行時に第１油圧アクチュエータ１２１を駆動させた際、第１油圧アクチュエータ用方向切換弁５３ａに付与されるパイロット圧を第１指令圧から第２指令圧に漸増させるため、第１油圧ポンプ５１及び第２油圧ポンプ５２からの圧油が第１油圧アクチュエータ１２１に急激に供給されることがなく、走行モータ２２Ｌ，２２Ｒに供給される圧油の油量の急激な低下による走行速度の急激な低下を防止することができる。また、第２実施形態では、走行時に合流切換弁５６により第１油圧ポンプ５１及び第２油圧ポンプ５２から吐出された圧油を合流させるため、走行モータ２２Ｌ，２２Ｒに供給される圧油の油量の急激な低下を効果的に防止できる。 Next, when the operation lever 412R is operated from the state in which the traveling levers 413L and 413R are operated, the ECU 10 changes the primary pressure of the pilot pressure oil from the first command pressure to the second command to the electromagnetic pressure reducing valve 19. A second command for gradually increasing the pressure is transmitted. Thereafter, while the travel levers 413L and 413R and the work operation lever 412R are being operated, a command for holding the primary pressure of the pilot pressure oil at the second command pressure is transmitted to the electromagnetic pressure reducing valve 19. Thus, when the first hydraulic actuator 121 is driven during traveling, the first hydraulic pump is used to gradually increase the pilot pressure applied to the first hydraulic actuator direction switching valve 53a from the first command pressure to the second command pressure. The hydraulic oil 51 and the second hydraulic pump 52 are not suddenly supplied to the first hydraulic actuator 121, and the traveling speed is suddenly reduced due to the rapid decrease in the amount of hydraulic oil supplied to the traveling motors 22L and 22R. Can be prevented. In the second embodiment, the pressure oil discharged from the first hydraulic pump 51 and the second hydraulic pump 52 is merged by the merging switching valve 56 during traveling, so that the oil of the pressure oil supplied to the traveling motors 22L and 22R. A sudden drop in the amount can be effectively prevented.
　次いで、ＥＣＵ１０は、走行レバー４１３Ｌ，４１３Ｒが操作された状態のまま作業操作レバー４１２Ｒが操作されなくなると、電磁式減圧弁１９に対してパイロット圧油の１次圧力を第２指令圧から第１指令圧に漸減させる指令を発信する。その後、走行レバー４１３Ｌ，４１３Ｒのみが操作されている間は、電磁式減圧弁１９に対してパイロット圧油の１次圧力を第１指令圧に保持する指令を発信する。 Next, when the operation lever 412R is not operated while the traveling levers 413L and 413R are operated, the ECU 10 sets the primary pressure of the pilot pressure oil to the first command pressure from the second command pressure to the electromagnetic pressure reducing valve 19. A command to gradually decrease to the command pressure is transmitted. Thereafter, while only the travel levers 413L and 413R are being operated, a command for holding the primary pressure of the pilot pressure oil at the first command pressure is transmitted to the electromagnetic pressure reducing valve 19.
　さらに、ＥＣＵ１０は、走行レバー４１３Ｌ，４１３Ｒが操作されなくなると、電磁式減圧弁１９に対してパイロットポンプ５４からの１次圧力を第１指令値から基準値に増圧し保持する指令を発信する。 Further, when the travel levers 413L and 413R are not operated, the ECU 10 sends a command to the electromagnetic pressure reducing valve 19 to increase the primary pressure from the pilot pump 54 from the first command value to the reference value and hold it.
　第２実施形態では、電磁式減圧弁１９の下流側に複数の操作装置に至る分岐路を設置するだけで、複数の操作装置に対応する複数のアクチェータに本発明の制御を入れることができるため、操作装置の２次圧を制御するような複数の電磁比例弁が不要であり、油圧回路を安価な構成にて提供できる。 In the second embodiment, the control of the present invention can be applied to a plurality of actuators corresponding to a plurality of operation devices by simply installing branch paths that reach the plurality of operation devices downstream of the electromagnetic pressure reducing valve 19. A plurality of electromagnetic proportional valves for controlling the secondary pressure of the operating device is unnecessary, and a hydraulic circuit can be provided with an inexpensive configuration.
　以上、本発明の実施形態について図面に基づいて説明したが、具体的な構成は、これらの実施形態に限定されるものでないと考えられるべきである。本発明の範囲は、上記した実施形態の説明だけではなく特許請求の範囲によって示され、さらに特許請求の範囲と均等の意味および範囲内でのすべての変更が含まれる。 As mentioned above, although embodiment of this invention was described based on drawing, it should be thought that a specific structure is not limited to these embodiment. The scope of the present invention is shown not only by the above description of the embodiments but also by the scope of claims for patent, and further includes all modifications within the meaning and scope equivalent to the scope of claims for patent.
　１００　　油圧回路
　　１０　　ＥＣＵ
　　１１　　第１アクチュエータ
　　１２　　第２アクチュエータ
　　１３　　油圧ポンプ
　　１４　　パイロットポンプ
　　１５　　第１方向切換弁
　　１６　　第２方向切換弁
　　１７　　第１操作装置
　　１８　　第２操作装置
　　１９　　電磁式減圧弁
　　　５　　油圧回路
　　５１　　第１油圧ポンプ
　　５２　　第２油圧ポンプ
　　５３　　方向切換弁
　　５４　　パイロットポンプ
　　５５　　リモコン弁
　　５６　　合流切換弁
 
 

  100 Hydraulic circuit 10 ECU
DESCRIPTION OF SYMBOLS 11 1st actuator 12 2nd actuator 13 Hydraulic pump 14 Pilot pump 15 1st direction switching valve 16 2nd direction switching valve 17 1st operating device 18 2nd operating device 19 Electromagnetic pressure reducing valve 5 Hydraulic circuit 51 1st hydraulic pump 52 Second hydraulic pump 53 Directional switching valve 54 Pilot pump 55 Remote control valve 56 Junction switching valve


Claims (4)

  1. 　第１アクチュエータと、第２アクチュエータと、前記第１アクチュエータ及び前記第２アクチュエータに圧油を供給する油圧ポンプと、前記第１アクチュエータに供給される圧油の向きを切り換え流量を調節する第１方向切換弁と、前記第２アクチュエータに供給される圧油の向きを切り換え流量を調節する第２方向切換弁と、前記第１方向切換弁及び前記第２方向切換弁にパイロット圧油を供給するパイロットポンプと、前記第１方向切換弁に供給されるパイロット圧油の向きと圧力を操作に応じて切り換え調節可能な第１操作装置と、前記第２方向切換弁に供給されるパイロット圧油の向きと圧力を操作に応じて切り換え調節可能な第２操作装置と、前記第２操作装置と前記パイロットポンプとの間の油路に設けられ、前記第２操作装置に供給されるパイロット圧油の１次圧力を制御する圧力制御装置と、前記圧力制御装置に制御指令を発信する制御指令発信装置と、を備え、
    　前記制御指令発信装置は、前記第１操作装置が操作されている間は、前記圧力制御装置に対して前記１次圧力を基準圧から第１指令圧に減圧して保持する第１指令を発信し、
    　前記第１操作装置が操作された状態から前記第２操作装置が操作されると、前記圧力制御装置に対して前記１次圧力を前記第１指令圧から第２指令圧に漸増させる第２指令を発信する、作業車両の油圧回路。     A first actuator, a second actuator, a hydraulic pump for supplying pressure oil to the first actuator and the second actuator, and a first direction for switching the direction of the pressure oil supplied to the first actuator to adjust the flow rate. A switching valve, a second direction switching valve for switching the direction of the pressure oil supplied to the second actuator, and a pilot for supplying pilot pressure oil to the first direction switching valve and the second direction switching valve A pump, a first operating device capable of switching and adjusting a direction and pressure of pilot pressure oil supplied to the first directional switching valve according to an operation, and a direction of pilot pressure oil supplied to the second directional switching valve A second operating device capable of switching and adjusting the pressure according to the operation, and an oil passage between the second operating device and the pilot pump, and the second operating device. Comprising a pressure controller for controlling the primary pressure of the supplied pilot pressure oil, and a control command transmitter which transmits a control command to the pressure control device,
    The control command transmission device transmits a first command for reducing and holding the primary pressure from a reference pressure to a first command pressure to the pressure control device while the first operation device is being operated. And
    When the second operating device is operated from the state where the first operating device is operated, a second command for gradually increasing the primary pressure from the first command pressure to the second command pressure with respect to the pressure control device. The hydraulic circuit of the work vehicle that transmits.
  2. 　前記制御指令発信装置は、前記第１操作装置が操作された状態のまま前記第２操作装置が操作されなくなると、前記圧力制御装置に対して前記１次圧力を前記第２指令圧から前記第１指令圧に漸減させる指令を発信する、請求項１に記載の作業車両の油圧回路。 When the second operating device is not operated while the first operating device is operated, the control command transmission device sends the primary pressure to the pressure control device from the second command pressure. The hydraulic circuit of the work vehicle according to claim 1, wherein a command for gradually decreasing the command pressure to 1 command pressure is transmitted.
  3. 　前記第１アクチュエータは第１走行用油圧モータであり、前記第２アクチュエータは作業用油圧アクチュエータである、請求項１又は２に記載の作業車両の油圧回路。 The hydraulic circuit for a work vehicle according to claim 1 or 2, wherein the first actuator is a first traveling hydraulic motor, and the second actuator is a working hydraulic actuator.
  4. 　前記第１走行用油圧モータ及び前記第１走行用油圧モータに圧油を供給する第１油圧ポンプを含む第１回路系統と、
    　前記作業用油圧アクチュエータ、第２走行用油圧モータ、並びに前記作業用油圧アクチュエータ及び前記第２走行用油圧モータに圧油を供給する第２油圧ポンプを含む第２回路系統と、
    　前記第１回路系統の圧油と前記第２回路系統の圧油を合流させる合流切換弁と、を備える、請求項３に記載の作業車両の油圧回路。
     
     

          A first circuit system including a first hydraulic pump for supplying pressure oil to the first traveling hydraulic motor and the first traveling hydraulic motor;
    A second circuit system including a second hydraulic pump for supplying pressure oil to the working hydraulic actuator, a second traveling hydraulic motor, and the working hydraulic actuator and the second traveling hydraulic motor;
    4. The hydraulic circuit for a work vehicle according to claim 3, further comprising a merging switching valve that merges the pressure oil of the first circuit system and the pressure oil of the second circuit system. 5.



PCT/JP2019/008773 2018-03-27 2019-03-06 Hydraulic circuit for work vehicle WO2019188061A1 (en)

Priority Applications (3)

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KR1020207007942A KR102642076B1 (en) 2018-03-27 2019-03-06 Hydraulic circuit of work vehicle
EP19778403.6A EP3779212A4 (en) 2018-03-27 2019-03-06 Hydraulic circuit for work vehicle
AU2019246449A AU2019246449A1 (en) 2018-03-27 2019-03-06 Hydraulic circuit for work vehicle

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JP2018060461A JP6893894B2 (en) 2018-03-27 2018-03-27 Work vehicle flood control circuit

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JP7444798B2 (en) 2021-01-18 2024-03-06 ヤンマーホールディングス株式会社 construction machinery

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JPS646501A (en) * 1987-06-30 1989-01-11 Hitachi Construction Machinery Control apparatus for load sensing hydraulic drive circuit
JPH0885974A (en) * 1994-09-19 1996-04-02 Hitachi Constr Mach Co Ltd Operation system of construction machine
JPH0893001A (en) * 1994-09-26 1996-04-09 Komatsu Ltd Hydraulic pilot operating circuit
JP2005121155A (en) 2003-10-17 2005-05-12 Hitachi Constr Mach Co Ltd Hydraulic control circuit for construction machinery
JP2006125627A (en) 2004-09-29 2006-05-18 Kobelco Contstruction Machinery Ltd Hydraulic circuit of construction machinery
JP2011196436A (en) * 2010-03-18 2011-10-06 Yanmar Co Ltd Hydraulic circuit for working vehicle
WO2013153984A1 (en) * 2012-04-10 2013-10-17 日立建機株式会社 Hydraulic drive device of construction machine
WO2014068973A1 (en) * 2012-10-30 2014-05-08 川崎重工業株式会社 Hydraulic pressure control device

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JP3612256B2 (en) * 1999-12-22 2005-01-19 新キャタピラー三菱株式会社 Hydraulic circuit of work machine
WO2011114929A1 (en) * 2010-03-18 2011-09-22 ヤンマー株式会社 Hydraulic circuit for working vehicle

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JPS646501A (en) * 1987-06-30 1989-01-11 Hitachi Construction Machinery Control apparatus for load sensing hydraulic drive circuit
JPH0885974A (en) * 1994-09-19 1996-04-02 Hitachi Constr Mach Co Ltd Operation system of construction machine
JPH0893001A (en) * 1994-09-26 1996-04-09 Komatsu Ltd Hydraulic pilot operating circuit
JP2005121155A (en) 2003-10-17 2005-05-12 Hitachi Constr Mach Co Ltd Hydraulic control circuit for construction machinery
JP2006125627A (en) 2004-09-29 2006-05-18 Kobelco Contstruction Machinery Ltd Hydraulic circuit of construction machinery
JP2011196436A (en) * 2010-03-18 2011-10-06 Yanmar Co Ltd Hydraulic circuit for working vehicle
WO2013153984A1 (en) * 2012-04-10 2013-10-17 日立建機株式会社 Hydraulic drive device of construction machine
WO2014068973A1 (en) * 2012-10-30 2014-05-08 川崎重工業株式会社 Hydraulic pressure control device

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Title
See also references of EP3779212A4

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KR20200135275A (en) 2020-12-02
KR102642076B1 (en) 2024-02-28
AU2019246449A1 (en) 2020-10-08
EP3779212A1 (en) 2021-02-17
JP6893894B2 (en) 2021-06-23
EP3779212A4 (en) 2021-12-29
JP2019173803A (en) 2019-10-10

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