WO2010026848A1 - 作業車両の油圧回路 - Google Patents
作業車両の油圧回路 Download PDFInfo
- Publication number
- WO2010026848A1 WO2010026848A1 PCT/JP2009/063865 JP2009063865W WO2010026848A1 WO 2010026848 A1 WO2010026848 A1 WO 2010026848A1 JP 2009063865 W JP2009063865 W JP 2009063865W WO 2010026848 A1 WO2010026848 A1 WO 2010026848A1
- Authority
- WO
- WIPO (PCT)
- Prior art keywords
- switching valve
- lever
- mode switching
- pto
- port
- Prior art date
Links
- 239000010720 hydraulic oil Substances 0.000 claims abstract description 92
- 230000007246 mechanism Effects 0.000 claims description 51
- 238000005086 pumping Methods 0.000 claims description 4
- 239000003921 oil Substances 0.000 abstract description 122
- 239000003381 stabilizer Substances 0.000 description 15
- 230000002093 peripheral effect Effects 0.000 description 10
- 239000004576 sand Substances 0.000 description 8
- 239000012530 fluid Substances 0.000 description 7
- 238000009412 basement excavation Methods 0.000 description 5
- 230000005856 abnormality Effects 0.000 description 3
- 230000007257 malfunction Effects 0.000 description 3
- 239000011800 void material Substances 0.000 description 3
- 230000008602 contraction Effects 0.000 description 2
- 230000000694 effects Effects 0.000 description 2
- 238000012423 maintenance Methods 0.000 description 2
- 238000000034 method Methods 0.000 description 2
- 238000013021 overheating Methods 0.000 description 2
- 238000010586 diagram Methods 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 239000000463 material Substances 0.000 description 1
Images
Classifications
-
- 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
-
- 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
- E02F9/2004—Control mechanisms, e.g. control levers
-
- E—FIXED CONSTRUCTIONS
- E02—HYDRAULIC ENGINEERING; FOUNDATIONS; SOIL SHIFTING
- E02F—DREDGING; SOIL-SHIFTING
- E02F9/00—Component parts of dredgers or soil-shifting machines, not restricted to one of the kinds covered by groups E02F3/00 - E02F7/00
- E02F9/20—Drives; Control devices
- E02F9/22—Hydraulic or pneumatic drives
- E02F9/2278—Hydraulic circuits
- E02F9/2292—Systems with two or more pumps
-
- E—FIXED CONSTRUCTIONS
- E02—HYDRAULIC ENGINEERING; FOUNDATIONS; SOIL SHIFTING
- E02F—DREDGING; SOIL-SHIFTING
- E02F9/00—Component parts of dredgers or soil-shifting machines, not restricted to one of the kinds covered by groups E02F3/00 - E02F7/00
- E02F9/20—Drives; Control devices
- E02F9/22—Hydraulic or pneumatic drives
- E02F9/2278—Hydraulic circuits
- E02F9/2296—Systems with a variable displacement pump
-
- 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
- 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
- F15B2211/31—Directional control characterised by the positions of the valve element
- F15B2211/3105—Neutral or centre positions
- F15B2211/3116—Neutral or centre positions the pump port being open in the centre position, e.g. so-called open centre
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
- F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
- F15B2211/00—Circuits for servomotor systems
- F15B2211/30—Directional control
- F15B2211/315—Directional control characterised by the connections of the valve or valves in the circuit
- F15B2211/31523—Directional control characterised by the connections of the valve or valves in the circuit being connected to a pressure source and an output member
- F15B2211/31541—Directional control characterised by the connections of the valve or valves in the circuit being connected to a pressure source and an output member having a single pressure source and 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
- F15B2211/50—Pressure control
- F15B2211/505—Pressure control characterised by the type of pressure control means
- F15B2211/50509—Pressure control characterised by the type of pressure control means the pressure control means controlling a pressure upstream of the pressure control means
- F15B2211/50518—Pressure control characterised by the type of pressure control means the pressure control means controlling a pressure upstream of the pressure control means using pressure relief valves
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
- F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
- F15B2211/00—Circuits for servomotor systems
- F15B2211/50—Pressure control
- F15B2211/515—Pressure control characterised by the connections of the pressure control means in the circuit
- F15B2211/5157—Pressure control characterised by the connections of the pressure control means in the circuit being connected to a pressure source and a return line
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
- F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
- F15B2211/00—Circuits for servomotor systems
- F15B2211/50—Pressure control
- F15B2211/515—Pressure control characterised by the connections of the pressure control means in the circuit
- F15B2211/5159—Pressure control characterised by the connections of the pressure control means in the circuit being connected to an output member and a return line
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
- F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
- F15B2211/00—Circuits for servomotor systems
- F15B2211/50—Pressure control
- F15B2211/55—Pressure control for limiting a pressure up to a maximum pressure, e.g. by using a pressure relief valve
-
- 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
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
- Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
- Y10T137/00—Fluid handling
- Y10T137/8593—Systems
- Y10T137/85978—With pump
- Y10T137/86131—Plural
Definitions
- the present invention relates to a technique for a work vehicle including two or more hydraulic pumps.
- the hydraulic circuit of the work vehicle includes a loader control valve 500 as shown in FIG.
- hydraulic oil pumped by one hydraulic pump is supplied to the loader control valve 500 via a pipe 536 and a pump port 551.
- the operation of the dump cylinder switching valve 510 and the bucket lift cylinder switching valve 520 can be controlled.
- the hydraulic oil pumped by the one hydraulic pump can be taken out via the PTO ports 560 and 561.
- the other working device connected to the work vehicle can be driven using the extracted hydraulic fluid.
- the hydraulic oil extracted by the PTO switching valve is disadvantageous in that it may not be able to drive a work device that requires a large flow rate.
- the discharge amount of the hydraulic oil from the one hydraulic pump is about 10 GPM (gallon / min)
- a working device that requires 17 GPM of hydraulic oil cannot be driven.
- the present invention has been made in view of the problems as described above, and provides a work vehicle capable of joining hydraulic oils pumped by the two hydraulic pumps and taking out the joined hydraulic oils. With the goal.
- two or more independent hydraulic pumps that pump hydraulic fluid
- a mode switching valve that can be switched to a merging position that merges hydraulic fluid pumped by the two or more hydraulic pumps
- a PTO port for taking out the hydraulic oil
- a PTO switching valve that is arranged on the downstream side of the mode switching valve and switches the hydraulic oil to the PTO port so as to be pressure-feedable.
- the mode switching valve is provided integrally with a control valve including the PTO switching valve.
- the mode switching valve includes the merging position, a return position for returning hydraulic oil pumped by the two or more hydraulic pumps to the tank, and hydraulic oil pumped by the two or more hydraulic pumps.
- the operation positions for pressure feeding to other control valves arranged on the downstream side can be switched without joining each other.
- the PTO switching valve has a continuous position in which hydraulic oil is switched to be able to be pumped to the PTO port, and the PTO switching valve is switched to the continuous position.
- An interlock mechanism that enables the mode switching valve to be switched to the merging position only when there is an engine.
- the interlock mechanism switches the mode switching valve from the merging position to another position when the PTO switching valve is switched from the continuous position to another position.
- the interlock mechanism is a position in which the mode switching valve exceeds a position other than the merging position by a predetermined dimension while the PTO switching valve is being switched from the continuous position to another position. To move up to.
- start prohibiting means for prohibiting engine start is provided.
- engine speed limiting means for limiting the engine speed to a predetermined speed or less is provided.
- hydraulic oils pumped by mutually independent hydraulic pumps can be merged, and the merged hydraulic oil can be taken out via the PTO port.
- the PTO port can be merged, and the merged hydraulic oil can be taken out via the PTO port.
- the present invention does not require a separate space for arranging the mode switching valve, and can save space. Along with this, piping for connecting the mode switching valve and the control valve is also unnecessary, so that the number of parts and cost can be reduced.
- the hydraulic oil can be returned to the tank through a short path by switching the mode switching valve to the return position.
- pressure loss due to piping of the hydraulic circuit or the like can be reduced.
- the merging position, the return position, and the working position in the same valve it is not necessary to secure a space for arranging the valve separately, and space can be saved.
- the plurality of positions in an integrated valve the number of parts and cost can be reduced.
- hydraulic oils pumped from two or more hydraulic pumps can be merged only when hydraulic fluid is always taken out from the PTO port at all times (continuously).
- the joined hydraulic oil is pumped from a port other than the PTO port, and it is possible to prevent a downstream work device from malfunctioning due to a large flow rate, thereby improving the safety of the work vehicle. be able to.
- hydraulic oils pumped from two or more hydraulic pumps can be merged only when hydraulic fluid is always taken out from the PTO port at all times (continuously). Moreover, the merging of the hydraulic oil can be stopped simply by switching the PTO switching valve from the continuous position.
- the present invention can reliably switch the mode switching valve to a position other than the merge position.
- the present invention can prevent the working device connected to the PTO port from being driven simultaneously with the start of the engine. Thereby, the safety of the work vehicle can be improved.
- the present invention can suppress an increase in temperature of the joined hydraulic oil when the hydraulic oil pumped from two or more hydraulic pumps are joined. This can prevent the occurrence of abnormalities such as overheating.
- the right view which shows the whole structure of the work vehicle which concerns on one Embodiment of this invention.
- the whole schematic diagram showing the hydraulic circuit composition which a work vehicle similarly comprises.
- the partially enlarged view which similarly shows a hydraulic circuit structure.
- the left view which similarly shows operating devices, such as a loader.
- the left side enlarged view which similarly shows the operation
- the left side enlarged view which similarly shows the operation
- the left side enlarged view which similarly shows the operation
- the left view which similarly shows an engine speed limiting means.
- the left side enlarged view which similarly shows the operation
- the left view which shows other embodiment of an engine speed limiting means.
- the work vehicle 1 which is one embodiment of the work vehicle according to the present invention will be described.
- the work vehicle 1 performs an earth and sand transport operation, an excavation operation, and the like using a work device.
- the work vehicle 1 mainly includes a traveling vehicle 2, a loader 3, a backhoe 4, and the like.
- the traveling vehicle 2 is a main body of the work vehicle 1.
- the traveling vehicle 2 mainly includes a body frame 5, an engine 6, a hood 7, front wheels 8 and 8, rear wheels 9 and 9, a steering unit 10, and the like.
- the machine body frame 5 is a main structure of the traveling vehicle 2.
- the body frame 5 is a substantially box-shaped member composed of a plurality of plate materials with the longitudinal direction as the front-rear direction.
- the engine 6 generates power for driving the work vehicle 1.
- the engine 6 is provided in the front part of the body frame 5.
- the bonnet 7 covers equipment such as the engine 6 provided in the traveling vehicle 2.
- the bonnet 7 is provided in the front part of the body frame 5.
- the bonnet 7 is configured to cover equipment such as the engine 6 provided in the front part of the body frame 5.
- the front wheels 8 and 8 support the body frame 5. Front wheels 8 and 8 are respectively provided on the left and right of the front lower portion of the body frame 5. The front wheels 8 and 8 are rotated by the power generated by the engine 6.
- the rear wheels 9 and 9 support the body frame 5.
- the rear wheels 9, 9 are provided on the left and right of the rear lower part of the body frame 5, respectively.
- the rear wheels 9, 9 are rotated by the power generated by the engine 6.
- the control unit 10 is a place where the operator operates the work vehicle 1.
- the control unit 10 is provided at a substantially central part in the front and rear direction of the body frame 5.
- the control unit 10 mainly includes a handle 11, a seat 12, an operation device 300 such as a loader, a backhoe operation device 13, and the like.
- the handle 11 steers the front wheels 8.8.
- the handle 11 is provided at the front part of the control unit 10.
- the seat 12 is for an operator to sit on.
- the seat 12 is provided behind the handle 11.
- the operation device 300 such as a loader is for operating a work device such as the loader 3 and setting the engine speed of the work vehicle 1 and the like.
- An operation device 300 such as a loader is provided on the side of the seat 12 (on the right side in the present embodiment).
- the backhoe operating device 13 is for operating the backhoe 4 and the like.
- the backhoe operating device 13 is provided behind the seat 12.
- Loader 3 is a working device for carrying earth and sand.
- the loader 3 mainly includes bucket lift arms 15 and 15, a loader bucket 16, bucket lift cylinders 17 and 17, dump cylinders 18 and 18, and the like.
- the bucket lift arms 15 and 15 are members that are main structures of the loader 3.
- the rear end portion of the bucket lift arm 15 is supported on the left and right sides of the body frame 5 so as to be vertically rotatable.
- the loader bucket 16 is a member for loading earth and sand.
- the loader bucket 16 is supported by the front end portions of the bucket lift arms 15 and 15 so as to be vertically rotatable.
- the bucket lift cylinders 17 and 17 are hydraulic cylinders that can be expanded and contracted by an operation device 300 such as a loader.
- the rear end portions of the bucket lift cylinders 17 and 17 are respectively supported on the left and right sides of the machine body frame 5 so as to be vertically rotatable.
- the front end portions of the bucket lift cylinders 17 and 17 are supported by the middle portions of the bucket lift arms 15 and 15 so as to be vertically rotatable.
- the dump cylinders 18 and 18 are hydraulic cylinders that can be expanded and contracted by an operation device 300 such as a loader.
- the rear ends of the dump cylinders 18 and 18 are supported on the left and right sides of the body frame 5 so as to be vertically rotatable.
- the front ends of the dump cylinders 18 and 18 are connected to the loader bucket 16 via link mechanisms 19 and 19, respectively.
- the bucket lift arms 15 and 15 can be moved up and down by extending and retracting the bucket lift cylinders 17 and 17.
- the loader bucket 16 can be rotated up and down with respect to the bucket lift arms 15 and 15 by expanding and contracting the dump cylinders 18 and 18.
- the work vehicle 1 performs a transporting operation of earth and sand by combining the rotating operations of the bucket lift arms 15 and 15 and the loader bucket 16.
- Backhoe 4 is used for excavating earth and sand.
- the backhoe 4 mainly includes stabilizers 20 and 20, stabilizer cylinders 21 and 21, a boom bracket 22, swing cylinders 23 and 23, a boom 24, a boom cylinder 25, an arm 26, an arm cylinder 27, a bucket 28, a bucket cylinder 29, and the like.
- Stabilizers 20 and 20 support work vehicle 1 when excavation work is performed by backhoe 4. One end of each of the stabilizers 20 and 20 is supported on the left and right rear portions of the body frame 5 so as to be vertically rotatable.
- Stabilizer cylinders 21 and 21 are hydraulic cylinders that can be expanded and contracted by the backhoe operating device 13. One end of each of the stabilizer cylinders 21 and 21 is supported on the rear left and right of the body frame 5 so as to be vertically rotatable. The other ends of the stabilizer cylinders 21 and 21 are respectively supported by the other ends of the stabilizers 20 and 20 so as to be vertically rotatable.
- the boom bracket 22 is a member that is a main structure of the backhoe 4.
- the front end of the boom bracket 22 is supported by the rear end of the body frame 5 so as to be able to turn left and right.
- the swing cylinders 23 and 23 are hydraulic cylinders that can be expanded and contracted by the backhoe operating device 13.
- the swing cylinders 23 and 23 are provided on the left and right sides of the body frame 5 and the boom bracket 22, respectively.
- One end of each of the swing cylinders 23 and 23 is supported by the rear end portion of the body frame 5 so as to be able to turn left and right.
- the other ends of the swing cylinders 23 and 23 are respectively supported on the front end of the boom bracket 22 so as to be rotatable left and right.
- the boom 24 is a member that is a main structure of the backhoe 4. One end of the boom 24 is supported by the rear end of the boom bracket 22 so as to be rotatable up and down.
- the boom cylinder 25 is a hydraulic cylinder that can be expanded and contracted by the backhoe operating device 13. One end of the boom cylinder 25 is supported by the upper part of the rear end of the boom bracket 22 so as to be vertically rotatable. The other end of the boom cylinder 25 is supported by the middle part of the boom 24 so as to be vertically rotatable.
- the arm 26 is a member that is a main structure of the backhoe 4. One end of the arm 26 is supported by the other end of the boom 24 so as to be rotatable up and down.
- the arm cylinder 27 is a hydraulic cylinder that can be expanded and contracted by the backhoe operating device 13. One end of the arm cylinder 27 is supported by the middle part of the boom 24 so as to be vertically rotatable. The other end of the arm cylinder 27 is supported by one end of the arm 26 so as to be rotatable up and down.
- the bucket 28 is a member for loading earth and sand.
- One end of the bucket 28 is supported by the other end of the arm 26 so as to be vertically rotatable.
- the bucket cylinder 29 is a hydraulic cylinder that can be expanded and contracted by the backhoe operating device 13.
- One end of the bucket cylinder 29 is supported by the middle part of the arm 26 so as to be vertically rotatable.
- the other end of the bucket cylinder 29 is supported by the bucket 28 so as to be rotatable up and down.
- the other ends of the stabilizers 20 and 20 can be grounded by controlling the expansion and contraction of the stabilizer cylinders 21 and 21.
- the posture of the work vehicle 1 during excavation work can be stabilized.
- the boom bracket 22 can be rotated right and left by extending and retracting the swing cylinders 23 and 23.
- the boom 24 can be rotated up and down.
- the arm 26 can be rotated up and down with respect to the boom 24 by expanding and contracting the arm cylinder 27.
- the bucket 28 can be rotated up and down with respect to the arm 26.
- the work vehicle 1 performs excavation work such as earth and sand by combining the pivot operations of the boom bracket 22, the boom 24, the arm 26, and the bucket 28.
- the hydraulic circuit 100 is a hydraulic circuit provided in the work vehicle 1.
- the hydraulic circuit 100 mainly includes an HST section 110, a reservoir tank 120, a hydraulic pump section 130, a power steering valve section 140, a loader control valve 200, a backhoe control valve 150, and the like.
- the HST section 110 is for shifting the work vehicle 1 by the power of the engine 6.
- the reservoir tank 120 is an embodiment of the tank according to the present invention, and is a container for storing hydraulic oil used in the hydraulic circuit 100.
- the reservoir tank 120 can also be configured to be used as a mission case included in the work vehicle 1.
- the hydraulic pump section 130 pumps hydraulic oil by the power of the engine 6.
- the hydraulic pump section 130 includes a port 131 that is an opening for connecting a pipe.
- the hydraulic pump section 130 includes discharge ports 132, 133, and 134 through which hydraulic oil is discharged by independent hydraulic pumps.
- the pipe 121 is a pipe that connects the reservoir tank 120 and the port 131 of the hydraulic pump section 130.
- the hydraulic pump section 130 sucks the hydraulic oil in the reservoir tank 120 through the pipe 121 and the port 131 and discharges it from the discharge ports 132, 133, and 134.
- the power steering valve section 140 controls the operation of the steering cylinder 141 that steers the front wheels 8 and 8.
- the power steering valve section 140 performs expansion / contraction control of the steering cylinder 141 in accordance with the operation of the handle 11.
- the power steering valve section 140 includes a port 142 that is an opening for connecting piping.
- the pipe 135 is a pipe that connects the discharge port 134 of the hydraulic pump section 130 and the port 142 of the power steering valve section 140.
- the power steering valve section 140 controls the operation of the steering cylinder 141 using hydraulic oil supplied via the discharge port 134 and the pipe 135.
- the loader control valve 200 controls the operations of the bucket lift cylinders 17 and 17 and the dump cylinders 18 and 18.
- the loader control valve 200 includes a pump port 251, which is an opening for connecting pipes, a tank port 252, a carry over port 253, dump cylinder ports 254 and 255, bucket lift cylinder ports 256 and 257, ports 258 and so on. 259, PTO ports 260 and 261 and the like.
- the pipe 136 is a pipe that connects the discharge port 133 of the hydraulic pump section 130 and the pump port 251 of the loader control valve 200.
- the pipe 137 is a pipe that connects the discharge port 132 of the hydraulic pump section 130 and the port 258 of the loader control valve 200.
- the pipe 262 is a pipe that connects the tank port 252 of the loader control valve 200 and the reservoir tank 120.
- the backhoe control valve 150 controls the operation of the stabilizer cylinders 21 and 21, the swing cylinders 23 and 23, the boom cylinder 25, the arm cylinder 27, and the bucket cylinder 29.
- the backhoe control valve 150 includes ports 151 and 152 that are openings for connecting pipes.
- the pipe 263 is a pipe that connects the carryover port 253 of the loader control valve 200 and the port 151 of the backhoe control valve 150.
- the pipe 264 is a pipe that connects the port 259 of the loader control valve 200 and the port 152 of the backhoe control valve 150.
- the backhoe control valve 150 controls the operations of the stabilizer cylinder 21, the swing cylinders 23 and 23, and the arm cylinder 27 using hydraulic oil supplied through the pipe 263 and the port 151.
- the backhoe control valve 150 controls the operation of the stabilizer cylinder 21, the bucket cylinder 29, and the boom cylinder 25 using hydraulic oil supplied through the pipe 264 and the port 152.
- the work vehicle 1 is configured to include the backhoe control valve 150 on the downstream side of the loader control valve 200, but the present invention is not limited to this. That is, instead of the backhoe control valve 150, it is possible to provide a control valve or the like for switching the operation of the lift cylinder that moves the mounted work machine up and down. It is also possible to adopt a configuration without a control valve or the like.
- the loader control valve 200 mainly includes a dump cylinder switching valve 210, a bucket lift cylinder switching valve 220, a mode switching valve 230, a PTO switching valve 240, and the like.
- the dump cylinder switching valve 210 is disposed between the pump port 251 and the dump cylinders 18 and 18, and the operation of the dump cylinders 18 and 18 is switched by switching the flow path of the hydraulic oil pumped to the dump cylinders 18 and 18. This is a switching valve that switches between the two.
- the dump cylinder switching valve 210 is a 6-port, 3-position (position A, B, C) direction control valve. The position of the dump cylinder switching valve 210 can be switched by operating a loader operation lever 310 provided in an operation device 300 such as a loader.
- the oil passage 270 is an oil passage connecting the pump port 251 and the dump cylinder switching valve 210.
- the oil passage 271 is an oil passage connecting the oil passage 270 and the oil passage 272.
- a relief valve 271 a is provided in the middle of the oil passage 271.
- the oil passage 272 is an oil passage connected to the tank port 252.
- the oil passage 273 is an oil passage connecting the dump cylinder switching valve 210 and the middle portion of the oil passage 274.
- the oil passage 274 is an oil passage connecting the dump cylinder port 254 and the oil passage 272. In the middle of the oil passage 274 and in the vicinity of the connecting portion between the oil passage 274 and the oil passage 272, an anti-void relief valve 274a is provided.
- the oil passage 275 is an oil passage connecting the dump cylinder switching valve 210 and the middle portion of the oil passage 276.
- the oil passage 276 is an oil passage connecting the dump cylinder port 255 and the oil passage 272.
- a relief valve 276a with an anti-void is provided in the middle of the oil passage 276 and in the vicinity of the connecting portion between the oil passage 276 and the oil passage 272.
- the pipe 265 is a pipe that connects the dump cylinder port 254 and the bottom chambers of the dump cylinders 18 and 18.
- the pipe 266 is a pipe that connects the dump cylinder port 255 and the rod chambers of the dump cylinders 18 and 18.
- the hydraulic oil discharged from the discharge port 133 is pumped to the dump cylinder switching valve 210 via the pipe 136, the pump port 251, and the oil passage 270.
- the dump cylinder switching valve 210 By switching the dump cylinder switching valve 210 to the position C, the hydraulic oil is pumped to the bottom chambers of the dump cylinders 18 and 18 through the oil passage 273, the oil passage 274, the dump cylinder port 254, and the pipe 265. The As a result, the dump cylinders 18 and 18 can be extended. Further, by switching the dump cylinder switching valve 210 to the position B, the hydraulic oil passes through the oil passage 275, the oil passage 276, the dump cylinder port 255, and the piping 266 to the rod chamber of the dump cylinders 18 and 18. Pumped.
- the dump cylinders 18 can be shortened.
- the dump cylinders 18 and 18 can be expanded and contracted by switching the position of the dump cylinder switching valve 210. Thereby, the loader bucket 16 can be rotated up and down with respect to the bucket lift arms 15 and 15.
- the bucket lift cylinder switching valve 220 is disposed between the dump cylinder switching valve 210 and the bucket lift cylinders 17, 17, and changes the flow path of the hydraulic oil pressure-fed to the bucket lift cylinders 17, 17. This is a switching valve for switching the operation of the lift cylinders 17.
- the bucket lift cylinder switching valve 220 is a directional control valve having 6 ports and 4 positions (positions D, E, F, and G). The position of the bucket lift cylinder switching valve 220 can be switched by operating a loader operation lever 310 provided in an operation device 300 such as a loader.
- the oil passage 277 is an oil passage connecting the dump cylinder switching valve 210 and the bucket lift cylinder switching valve 220.
- the oil passage 278 is an oil passage that connects the bucket lift cylinder switching valve 220 and the middle portion of the oil passage 279.
- the oil passage 279 is an oil passage connecting the bucket lift cylinder port 256 and the oil passage 272.
- a check valve 279 a is provided in the middle of the oil passage 279 and in the vicinity of the connecting portion between the oil passage 279 and the oil passage 272.
- the oil passage 280 is an oil passage connecting the bucket lift cylinder switching valve 220 and the bucket lift cylinder port 257.
- the pipe 267 is a pipe connecting the bucket lift cylinder port 256 and the rod chambers of the bucket lift cylinders 17 and 17.
- the pipe 268 is a pipe that connects the bucket lift cylinder port 257 and the bottom chambers of the bucket lift cylinders 17 and 17.
- the hydraulic oil that has passed through the dump cylinder switching valve 210 is pumped to the bucket lift cylinder switching valve 220 via the oil passage 277.
- the hydraulic oil is pumped to the bottom chambers of the bucket lift cylinders 17 and 17 through the oil passage 280, the bucket lift cylinder port 257, and the pipe 268. .
- the bucket lift cylinders 17 and 17 can be extended.
- the hydraulic oil passes through the oil passage 278, the oil passage 279, the bucket lift cylinder port 256, and the pipe 267 to the rod chamber of the bucket lift cylinders 17 and 17.
- the bucket lift cylinders 17 and 17 can be shortened.
- the bucket lift cylinders 17 and 17 can be expanded and contracted by switching the bucket lift cylinder switching valve 220.
- the bucket lift arm 15 can be moved up and down.
- the mode switching valve 230 is disposed between the bucket lift cylinder switching valve 220 and the carry over port 253, and is a switching valve that switches the hydraulic oil flow path.
- the mode switching valve 230 is a five-port, three-position direction control valve including primary ports 230a and 230b and secondary ports 230c, 230d, and 230e.
- the mode switching valve 230 communicates the port 230a and the port 230c, communicates the port 230d and the port 230e, and closes the port 230b, the port 230a, the port 230b, the port 230c, the port 230d, In addition, it is possible to switch between “return position J” that communicates with the port 230e, and “junction position K” that communicates between the port 230a and the ports 230c and 230d and communicates between the port 230b and the port 230e.
- the position of the mode switching valve 230 can be switched by operating a mode switching lever 340 provided in the operation device 300 such as a loader.
- the mode switching valve 230 includes springs 231 and 231 and a detent mechanism 232.
- the springs 231 and 231 hold the position of the mode switching valve 230 at the work position H.
- the mode switching valve 230 includes the springs 231 and 231.
- the present invention is not limited to this, and the mode switching valve 230 may not include the springs 231 and 231. Is possible.
- the detent mechanism 232 holds the position of the mode switching valve 230 at the return position J or the merge position K. When the mode switching valve 230 is switched to the return position J or the merge position K, the mode switching valve 230 is held at the return position J or the merge position K by the detent mechanism 232. Further, the mode switching valve 230 can be switched to another position by operating the mode switching lever 340 with an operation force equal to or greater than the holding force of the detent mechanism 232.
- the oil passage 281 is an oil passage connecting the bucket lift cylinder switching valve 220 and the port 230 a of the mode switching valve 230.
- the oil passage 282 is an oil passage connecting the port 230b of the mode switching valve 230 and the oil passage 272 (and thus the reservoir tank 120).
- the oil passage 283 is an oil passage connecting the port 230d of the mode switching valve 230 and the port 258 (and consequently the discharge port 132 of the hydraulic pump).
- the oil passage 284 is an oil passage that connects the port 230e of the mode switching valve 230 and the middle portion of the oil passage 285 (and eventually the port 152 of the backhoe control valve 150).
- the oil passage 285 is an oil passage connecting the oil passage 272 and the port 259.
- a relief valve 285a with an anti-void is provided in the middle of the oil passage 285 and in the vicinity of the connection portion between the oil passage 285 and the oil passage 272.
- the PTO switching valve 240 is a switching valve that is disposed between the mode switching valve 230 and the carryover port 253 and switches the flow path of the hydraulic oil that is pumped to the PTO ports 260 and 261.
- the PTO switching valve 240 is a 6-port 4-position directional control valve including primary ports 240a, 240b, and 240c and secondary ports 240d, 240e, and 240f.
- the PTO switching valve 240 communicates between the port 240a and the port 240d, communicates the "position L" that closes the ports 240b, 240c, 240e, and 240f, the port 240b and the port 240f, and the port 240c and the port 240e.
- PTO switching valve 240 can be switched by operating a PTO switching lever 360 provided in the operation device 300 such as a loader.
- the PTO switching valve 240 includes springs 241 and 241 and a detent mechanism 242.
- the springs 241 and 241 hold the position of the PTO switching valve 240 at the position L.
- the detent mechanism 242 holds the position of the PTO switching valve 240 at the continuous position P.
- the PTO switching valve 240 can be switched to another position by operating the PTO switching lever 360 with an operating force equal to or greater than the holding force of the detent mechanism 242.
- the oil passage 286 is an oil passage connecting the port 230c of the mode switching valve 230 and the port 240a of the PTO switching valve 240.
- the oil passage 287 is an oil passage connecting the middle portion of the oil passage 286 and the port 240 b of the PTO switching valve 240.
- a check valve 287 a is provided in the middle of the oil passage 287.
- the oil passage 288 is an oil passage that connects the port 240 c of the PTO switching valve 240 and the oil passage 272.
- the oil passage 289 is an oil passage that connects the port 240 d of the PTO switching valve 240 and the carryover port 253.
- the oil passage 290 is an oil passage that connects the port 240 e of the PTO switching valve 240 and the oil passage 291.
- the oil passage 291 is an oil passage connecting the PTO port 260 and the oil passage 272.
- a plug 291a is provided in the middle of the oil passage 291 and in the vicinity of the connecting portion between the oil passage 291 and the oil passage 272. If necessary, a configuration in which a relief valve or the like is interposed instead of the plug 291a may be employed.
- the oil passage 292 is an oil passage that connects the port 240 f of the PTO switching valve 240 and the middle portion of the oil passage 293.
- the oil passage 293 is an oil passage connecting the PTO port 261 and the oil passage 272.
- a plug 293a is provided in the middle of the oil passage 293 and in the vicinity of the connection portion between the oil passage 293 and the oil passage 272. If necessary, a configuration in which a relief valve or the like is interposed instead of the plug 293a may be employed.
- the mode switching lever 340 and the PTO switching lever 360 are provided with an interlock mechanism 400.
- the interlock mechanism 400 restricts the operation of the mode switching lever 340 (and thus the operation of the mode switching valve 230) based on the position of the PTO switching lever 360 (and hence the position of the PTO switching valve 240). More specifically, the interlock mechanism 400 operates the mode switching lever 340 so that the mode switching valve 230 can be switched to the merge position K only when the PTO switching valve 240 is in the continuous position P. Restrict.
- the mode switching valve 230 When performing excavation work or the like using the backhoe 4, the mode switching valve 230 is switched to the work position H. In this case, since the PTO switching valve 240 is not operated, the position of the PTO switching valve 240 is held at the position L by the springs 241 and 241.
- the hydraulic oil discharged from the discharge port 133 is a pipe 136, a pump port 251, an oil passage 270, a dump cylinder switching valve 210, an oil passage 277, a bucket lift cylinder switching valve 220, an oil
- the pressure is fed to the backhoe control valve 150 (see FIG. 2) via the path 281, the mode switching valve 230, the oil path 286, the PTO switching valve 240, the oil path 289, the carryover port 253, and the pipe 263.
- the hydraulic oil discharged from the discharge port 132 (see FIG. 2)
- the mode switching valve 230 is switched to the work position H.
- the hydraulic oil discharged from the discharge port 133 is a pipe 136, a pump port 251, an oil passage 270, a dump cylinder switching valve 210, an oil passage 277, a bucket lift cylinder switching valve 220, an oil
- the pressure is fed to the PTO switching valve 240 through the path 281, the mode switching valve 230, and the oil paths 286 and 287.
- the mode switching valve 230 When carrying earth and sand using the loader 3 or traveling, the mode switching valve 230 is switched to the return position J.
- the hydraulic oil discharged from the discharge port 133 is pumped to the dump cylinder switching valve 210 via the pipe 136, the pump port 251, and the oil passage 270.
- the loader 3 can be operated by the pressure-fed hydraulic oil.
- the hydraulic oil discharged from the discharge port 133 and passed through the dump cylinder switching valve 210 and the bucket lift cylinder switching valve 220 is pumped to the mode switching valve 230 via the oil passage 281.
- the hydraulic oil discharged from the discharge port 132 (see FIG. 2) is pressure-fed to the mode switching valve 230 through the pipe 137, the port 258, and the oil passage 283.
- the hydraulic oil discharged from the discharge ports 132 and 133 and pumped to the mode switching valve 230 is returned to the reservoir tank 120 (see FIG. 2) via the oil passage 282, the oil passage 272, the tank port 252 and the pipe 262. It is.
- the mode switching valve 230 by switching the mode switching valve 230 to the return position J, the hydraulic oil discharged from the discharge port 132 can be returned to the reservoir tank 120 through a short path. Thereby, when the work by the backhoe 4 is not performed, the pressure loss due to the piping can be reduced and the engine horsepower can be effectively utilized. Further, when the engine 6 is started, the mode switching valve 230 is switched to the return position J, whereby pressure loss due to piping can be reduced and the startability of the engine 6 can be improved. As a result, good startability of the engine 6 can be obtained even in a use environment where the outside air is at a low temperature.
- the PTO switching valve 240 When a working device that requires a flow rate larger than the flow rate of the hydraulic oil discharged from the discharge port 133 is connected to the PTO ports 260 and 261 and the work device performs the work, first, the PTO switching valve 240 is turned on. , Switch to continuous position P. Thereby, the restriction
- the hydraulic oil discharged from the discharge port 133 includes a pipe 136, a pump port 251, an oil passage 270, a dump cylinder switching valve 210, an oil passage 277, a bucket lift cylinder switching valve 220, and It is pumped to the mode switching valve 230 through the oil passage 281.
- the hydraulic oil discharged from the discharge port 132 (see FIG. 2) is pressure-fed to the mode switching valve 230 through the pipe 137, the port 258, and the oil passage 283.
- the hydraulic oil discharged from the discharge ports 132 and 133 and pumped to the mode switching valve 230 is merged in the mode switching valve 230.
- the joined hydraulic oil is pumped to the connected working device via the oil passages 286 and 287, the PTO switching valve 240, the oil passage 290, the oil passage 291 and the PTO port 260.
- the work vehicle 1 of the present embodiment is Two independent hydraulic pumps for pumping hydraulic oil, A mode switching valve 230 that can be switched to a merging position K where the hydraulic oil pumped by the two hydraulic pumps merges; PTO ports 260 and 261 for taking out hydraulic oil, A PTO switching valve 240 which is arranged downstream of the mode switching valve 230 and switches hydraulic oil to the PTO ports 260 and 261 so that it can be pumped. It comprises.
- the hydraulic oil discharged from the discharge port 132 and the discharge port 133 can be merged by switching the mode switching valve 230 to the merge position K.
- the mode switching valve 230 is The loader control valve 200 including the PTO switching valve 240 is integrally provided. With this configuration, it is not necessary to separately secure a space for arranging the mode switching valve 230, and space saving can be achieved. Furthermore, since piping for connecting the mode switching valve 230 and the loader control valve 200 is not necessary, the number of parts and the cost can be reduced. The present invention is not limited to such a configuration, and the mode switching valve 230 can be configured separately from the loader control valve 200. Furthermore, by using the loader control valve configured as in the present embodiment, the piping configuration of the hydraulic circuit 100 provided in the work vehicle 1 can be simplified. Specifically, the three-way joint required for the connecting portion 537a between the pipe 537 and the pipe 564 shown in FIG. Thereby, the piping configuration of the hydraulic circuit 100 can be simplified, and the number of parts and the number of assembly steps can be reduced.
- the mode switching valve 230 is Merge position K, A return position J for returning the hydraulic oil pumped by the two hydraulic pumps to the reservoir tank 120; A working position H for pumping the hydraulic oil pumped by the two hydraulic pumps to the backhoe control valve 150 disposed downstream, respectively, Can be switched.
- the mode oil can be returned to the reservoir tank 120 through a short path by switching the mode switching valve 230 to the return position J.
- the pressure loss due to the piping of the hydraulic circuit 100 or the like can be reduced.
- the merge position K, the return position J, and the work position H in the same valve, it is not necessary to secure a space for arranging the valve separately, and space saving can be achieved.
- the plurality of positions in an integrated valve the number of parts and cost can be reduced.
- the PTO switching valve 240 is It has a continuous position P where hydraulic oil is held in a state where it can be pumped to the PTO ports 260 and 261. Only when the PTO switching valve 240 is switched to the continuous position P, the interlock mechanism 400 that enables the mode switching valve 230 to be switched to the merging position K is provided. With this configuration, the safety of the work vehicle 1 can be improved.
- the hydraulic oil merged in the mode switching valve 230 is transferred to the oil passage 286,
- the pressure is fed to the backhoe control valve 150 through the PTO switching valve 240, the oil passage 289, the carryover port 253, the pipe 263, and the port 151.
- hydraulic fluid is not supplied from the port 152 to the backhoe control valve 150.
- the hydraulic fluid supplied from the port 151 causes the stabilizer cylinder 21, the swing cylinders 23 and 23, and the arm cylinder 27 shown in FIG.
- the interlock mechanism 400 is configured so that the mode switching valve 230 can be switched to the merging position K only when the PTO switching valve 240 is at the continuous position P, so that the hydraulic oil merged by the mode switching valve 230 is backhoeed.
- the supply to the control valve 150 can be prevented.
- the loader operating device 300 mainly includes a loader control valve 200, a loader operation lever 310, a dumping link mechanism 320, a bucket link mechanism 330, a mode switching lever 340, a mode switching link mechanism 350, a PTO switching lever 360, and a PTO.
- a link mechanism 370, a limit switch 380, a throttle lever 390, and the like are provided.
- the loader control valve 200 controls the operation of the bucket lift cylinders 17 and 17 and the dump cylinders 18 and 18 as described above.
- the loader control valve 200 is provided on the right side of the seat 12.
- the loader control valve 200 mainly includes a dump cylinder switching valve 210, a bucket lift cylinder switching valve 220, a mode switching valve 230, a PTO switching valve 240, and the like.
- the loader operation lever 310 switches the positions of the dump cylinder switching valve 210 and the bucket lift cylinder switching valve 220.
- the loader operation lever 310 is provided above the loader control valve 200.
- the dumping link mechanism 320 connects the loader operation lever 310 and the dump cylinder switching valve 210. By operating the loader operation lever 310 to the left and right, the position of the dump cylinder switching valve 210 can be switched.
- the bucket link mechanism 330 connects the loader operation lever 310 and the bucket lift cylinder switching valve 220. By operating the loader operation lever 310 back and forth, the position of the bucket lift cylinder switching valve 220 can be switched.
- the mode switching lever 340 switches the position of the mode switching valve 230.
- the mode switching lever 340 is provided above the loader control valve 200 and behind the loader operation lever 310.
- the mode switching lever 340 mainly includes a boss portion 341, a grip portion 342, an arm portion 343, a cam portion 344, and the like.
- the boss portion 341 is a substantially cylindrical member.
- the boss portion 341 is rotatably supported by a pivot shaft 345 whose axial direction substantially coincides with the left-right direction.
- the grip portion 342 is a substantially cylindrical member. One end of the grip portion 342 is fixed to the outer peripheral surface of the boss portion 341. The other end of the grip portion 342 extends rearward and upward. A grip 342 a is provided at the other end of the grip portion 342.
- the arm part 343 is a substantially rectangular plate-shaped member. One end of the arm portion 343 is fixed to the outer peripheral surface of the boss portion 341. The other end of the arm part 343 extends forward.
- the cam portion 344 is a substantially plate-like member. One end of the cam portion 344 is fixed to the outer peripheral surface of the boss portion 341. The other end of the cam portion 344 extends rearward, and the tip is formed in a substantially triangular shape.
- the mode switching link mechanism 350 connects the other end of the arm portion 343 and the mode switching valve 230.
- the operator grips the grip 342 (grip 342a) of the mode switching lever 340 and operates the mode switching lever 340 back and forth.
- the boss portion 341 rotates about the pivot shaft 345
- the other end of the arm portion 343 rotates up and down.
- the position of the mode switching valve 230 is switched via the mode switching link mechanism 350.
- the PTO switching lever 360 switches the position of the PTO switching valve 240.
- the PTO switching lever 360 is provided above the loader control valve 200 and behind the loader operation lever 310.
- the PTO switching lever 360 mainly includes a boss portion 361, a gripping portion 362, an arm portion 363, a cam portion 364, a contact portion 365, and the like.
- the boss portion 361 is a substantially cylindrical member.
- the boss portion 361 is rotatably supported by a pivot shaft 366 whose axial direction substantially coincides with the left-right direction.
- the boss portion 361 is disposed below the boss portion 341 of the mode switching lever 340.
- the gripping part 362 is a substantially columnar member. One end of the grip portion 362 is fixed to the outer peripheral surface of the boss portion 361. The other end of the grip portion 362 extends upward. A grip 362 a is provided at the other end of the grip 362.
- the arm portion 363 is a substantially rectangular plate member. One end of the arm portion 363 is fixed to the outer peripheral surface of the boss portion 361. The other end of the arm portion 363 extends forward.
- the cam portion 364 is a substantially plate-like member. One end of the cam portion 364 is fixed to the outer peripheral surface of the boss portion 361. The other end of the cam portion 364 extends upward.
- the cam portion 364 of the PTO switching lever 360 is disposed at substantially the same plane position in the left-right direction as the cam portion 344 of the mode switching lever 340.
- the contact portion 365 is a substantially plate-shaped member. One end of the contact portion 365 is fixed to the outer peripheral surface of the boss portion 361. The other end of the contact portion 365 extends rearward.
- the PTO link mechanism 370 connects the other end of the arm portion 363 and the PTO switching valve 240.
- the operator grips the grip 362 (grip 362a) of the PTO switching lever 360 and operates the PTO switching lever 360 back and forth.
- the boss portion 361 rotates about the pivot shaft 366
- the other end of the arm portion 363 rotates up and down.
- the position of the PTO switching valve 240 is switched via the PTO link mechanism 370.
- the limit switch 380 is an embodiment of the start prohibiting means according to the present invention, and is a switch whose contact is opened and closed depending on whether or not the operating piece 381 is pressed.
- the limit switch 380 is provided below the boss portion 361 of the PTO switching lever 360 and below the contact portion 365 of the PTO switching lever 360. More specifically, the limit switch 380 is disposed at a position where the operating piece 381 of the limit switch 380 is pressed by the contact portion 365 of the PTO switching lever 360 when the PTO switching valve 240 is switched to the continuous position P.
- the driving of a cell motor (not shown) that starts the engine 6 can be prohibited. That is, the engine 6 cannot be started while the operating piece 381 of the limit switch 380 is being pressed.
- the throttle lever 390 sets the rotation speed of the engine 6 of the work vehicle 1 (hereinafter simply referred to as “engine rotation speed”).
- engine rotation speed The throttle lever 390 is provided behind the PTO switching lever 360.
- the throttle lever 390 is configured to be rotatable back and forth around the lower end thereof. By rotating the throttle lever 390, the engine speed can be set. Specifically, the engine speed can be increased by rotating the throttle lever 390 forward. Further, the engine speed can be lowered by rotating the throttle lever 390 backward.
- the interlock mechanism 400 includes a cam portion 344 of the mode switching lever 340 and a cam portion 364 of the PTO switching lever 360.
- the position of the mode switching lever 340 when the mode switching valve 230 is at the working position H is the lever position Q
- the position of the mode switching lever 340 when the mode switching valve 230 is at the return position J is the lever position R.
- the position of the mode switching lever 340 in the merge position K is defined as a lever position S, respectively.
- the positions of the PTO switching lever 360 when the PTO switching valve 240 is in the positions L, M, and N and the continuous position P are defined as lever positions T, U, V, and W, respectively.
- the reference numerals of the positions of the mode switching valve 230 and the PTO switching valve 240 corresponding to the lever position are shown in parentheses together with the lever position reference.
- the mode switching lever 340 can be switched to the lever position Q or the lever position R. That is, the other end of the cam portion 364 of the PTO switching lever 360 faces upward and is positioned within the turning locus of the cam portion 344 of the mode switching lever 340, thereby limiting the turning range of the mode switching lever 340. However, it does not enter the rotation range when the mode switching lever 340 is switched to the lever position Q or the lever position R, and does not affect the rotation.
- the mode switching lever 340 When the mode switching lever 340 is switched to the lever position Q, the lower surface 344a of the cam portion 344 of the mode switching lever 340 and the upper surface 364a of the cam portion 364 of the PTO switching lever 360 come into contact with each other. That is, the cam portion 364 of the PTO switching lever 360 restricts the rotation of the mode switching lever 340 in the lever position S direction. As a result, the mode switching lever 340 cannot be switched to the lever position S. That is, the mode switching valve 230 cannot be switched to the merging position K, and the hydraulic oil discharged from the discharge ports 132 and 133 is not merged.
- the limit switch 380 for prohibiting the start of the engine 6 is provided.
- the start prohibiting means according to the present invention is configured by the limit switch 380, but the present invention is not limited to this. That is, the start prohibiting unit may be configured to detect that the PTO switching valve 240 is switched to the continuous position P and prohibit the start of the engine 6.
- the PTO switching lever 360 when the PTO switching lever 360 is switched to the lever position W, the lower surface 344a of the cam portion 344 of the mode switching lever 340 and the upper surface 364a of the cam portion 364 of the PTO switching lever 360 do not come into contact with each other.
- the cam portion 364 at the lever position W is positioned outside the rotation range of the cam portion 344 of the mode switching lever 340, and the lever position S of the mode switching lever 340 is moved by the cam portion 364 of the PTO switching lever 360.
- the restriction on the rotation of is released.
- the mode switching lever 340 can be switched to the lever position S. That is, the mode switching valve 230 can be switched to the merging position K only when the PTO switching valve 240 is in the continuous position P.
- the apex 364b of the cam portion 364 of the PTO switching lever 360 slides on the rear lower surface 344b of the cam portion 344 while the PTO switching lever 360 is being rotated from the lever position W to the lever position U.
- the mode switching lever 340 comes into contact with the apex 344c of the cam portion 344 of the mode switching lever 340.
- the mode switching lever 340 is rotated to a position (lever position Qa) that is rotated by a predetermined angle to the lever position R side beyond the lever position Q. That is, the mode switching valve 230 is moved by a predetermined dimension beyond the work position H to the return position J side.
- the mode switching valve 230 is returned to the working position H by the springs 231 and 231 and is held in that position.
- the mode switching lever 340 is returned to the lever position Q and held at that position.
- the mode switching lever 340 can be returned from the lever position S to the lever position Q. That is, the mode switching valve 230 can be switched to the working position H by operating the PTO switching lever 360.
- the interlock mechanism 400 is When the PTO switching valve 240 is switched from the continuous position P to the other positions L, M, and N, the mode switching valve 230 is switched from the merge position K to another position (working position H or return position J). It is. By comprising in this way, it can prevent that the backhoe 4 will be in a malfunctioning state beforehand, and can improve safety
- the interlock mechanism 400 is While the PTO switching valve 240 is being switched from the continuous position P to the other positions L, M, and N, the mode switching valve 230 is moved to a position other than the merging position K (working position H or return position J) by a predetermined dimension. It moves to a position that exceeds the limit. With this configuration, the mode switching valve 230 can be reliably switched to the working position H.
- the predetermined angle and the predetermined dimension are angles and dimensions that allow the mode switching valve 230 to return to the work position H by the springs 231 and 231.
- the loader or the like operating device 300 can be configured to include a throttle lever limiting mechanism 450 that is an embodiment of the engine speed limiting means according to the present invention.
- the throttle lever limiting mechanism 450 limits the range in which the throttle lever 390 can be rotated based on the position of the mode switching lever 340.
- the throttle lever limiting mechanism 450 mainly includes an intermediate link member 451, mode switching lever side link members 452 and 453, throttle lever side link members 454 and 455, and the like.
- the intermediate link member 451 is a substantially triangular plate member.
- the lower end side of the intermediate link member 451 is supported by the pivot shaft 451a so as to be able to rotate back and forth.
- the mode switching lever side link member 452 is a substantially rectangular plate-shaped member. One end side of the mode switching lever side link member 452 is supported by the pivot shaft 452a on the upper end side of the intermediate link member 451 so as to be vertically rotatable.
- the mode switching lever side link member 453 is a substantially rectangular plate-shaped member. One end side of the mode switching lever side link member 453 is fixed to the other end side of the mode switching lever side link member 452. On the other end side of the mode switching lever side link member 453, a through hole 453a that communicates with both surfaces thereof is formed. The grip portion 342 of the mode switching lever 340 is inserted through the through hole 453a.
- the throttle lever side link member 454 is a substantially rectangular plate-shaped member. One end side of the throttle lever side link member 454 is supported by the pivot shaft 454a so as to be pivotable up and down on the middle portion of the intermediate link member 451.
- the throttle lever side link member 455 is a substantially rectangular plate-shaped member. One end side of the throttle lever side link member 455 is fixed to the other end side of the throttle lever side link member 454. On the other end side of the throttle lever side link member 455, a through hole 455a that communicates both surfaces thereof is formed.
- the through hole 455a is a long hole whose longitudinal direction substantially coincides with the front-rear direction. A throttle lever 390 is inserted through the through hole 455a.
- the throttle lever 390 moves back and forth from the position where the engine speed is minimum to the maximum position (hereinafter simply referred to as “lever position X”). It can be rotated.
- the through hole 455a of the throttle lever side link member 455 is formed in a shape that does not come into contact with the throttle lever 390 when the throttle lever 390 rotates when the mode switching lever 340 is in a position other than the lever position S.
- the mode switching lever side link members 452 and 453 move backward in conjunction with the rotation of the mode switching lever 340.
- the mode switching lever side link members 452 and 453 By moving the mode switching lever side link members 452 and 453, the upper end side of the intermediate link member 451 is rotated backward.
- the throttle lever side link members 454 and 455 move rearward. In this case, since the through hole 455a of the throttle lever side link member 455 also moves backward, the forward rotation of the throttle lever 390 is restricted.
- the throttle lever 390 is rotated backward by a predetermined rotation angle by the throttle lever side link member 455.
- the throttle lever 390 comes into contact with the inner peripheral front end of the through hole 455a of the throttle lever side link member 455, so that the throttle lever 390 is moved to the lever position X. Can not be rotated.
- the engine speed can be limited to a predetermined value or less.
- the predetermined value of the engine speed is set in advance to a value that can suppress the temperature of the hydraulic oil in the work vehicle 1 to a temperature that does not cause an abnormality.
- the work vehicle 1 of the present embodiment is When the mode switching valve 230 is switched to the merging position K, a throttle lever limiting mechanism 450 that limits the engine speed to a predetermined speed or less is provided.
- a throttle lever limiting mechanism 450 that limits the engine speed to a predetermined speed or less is provided.
- the through hole 455a formed in the throttle lever side link member 455 has a shape that can restrict the rotation of the throttle lever 390 when the mode switching lever 340 is at the lever position S as described above, that is, the engine. It is formed in a shape that can limit the number of rotations to a predetermined value or less.
- a throttle lever limiting mechanism 460 described below can be configured.
- the throttle lever limiting mechanism 460 includes a link member 461.
- the link member 461 is a plate-like member. On one end side of the link member 461, a through hole 461a that communicates both surfaces thereof is formed. The grip portion 342 of the mode switching lever 340 is inserted through the through hole 461a. On the other end side of the link member 461, a through hole 461b that communicates both surfaces thereof is formed.
- the through hole 461b is a long hole whose longitudinal direction substantially coincides with the front-rear direction.
- a throttle lever 390 is inserted through the through hole 461b.
- movement aspect of the throttle lever limitation mechanism 460 comprised as mentioned above is demonstrated.
- the throttle lever 390 can be rotated back and forth from a position where the engine speed is minimum to a maximum position (lever position X).
- the through hole 461b of the link member 461 is formed to have a dimension that does not come into contact with the throttle lever 390 when the throttle lever 390 rotates when the mode switching lever 340 is in a position other than the lever position S.
- the link member 461 moves backward in conjunction with the rotation of the mode switching lever 340.
- the through hole 461b of the link member 461 also moves rearward, the forward rotation of the throttle lever 390 is restricted. That is, when the throttle lever 390 is at the lever position X, when the mode switching lever 340 is switched to the lever position S, the throttle lever 390 is rotated backward by the link member 461 by a predetermined rotation angle. In this case, if the throttle lever 390 is turned forward, the throttle lever 390 comes into contact with the inner peripheral front end of the through hole 461b of the link member 461, so that the throttle lever 390 is turned to the lever position X. I can't.
- the engine speed can be limited to a predetermined value or less.
- a throttle lever limiting mechanism 470 described below can be configured.
- the throttle lever limiting mechanism 470 includes a mode switching lever side arm 471, a throttle lever side arm 472, a cable 473, and the like.
- the mode switching lever side arm 471 is a substantially cylindrical member. One end of the mode switching lever side arm 471 is fixed to the outer peripheral surface of the boss portion 341. The other end of the mode switching lever arm 471 extends downward.
- the throttle lever side arm 472 is a substantially rectangular plate-shaped member. One end of the throttle lever side arm 472 is fixed to the lower end of the throttle lever 390. The other end of the throttle lever side arm 472 extends downward.
- the cable 473 is a string-like member that connects the mode switching lever side arm 471 and the throttle lever side arm 472. One end of the cable 473 is connected to the other end of the mode switching lever side arm 471. The other end of the cable 473 is connected to the other end of the throttle lever side arm 472.
- movement aspect of the throttle lever limitation mechanism 470 comprised as mentioned above is demonstrated.
- the throttle lever 390 can be rotated back and forth from a position where the engine speed is minimum to a maximum position (lever position X).
- the cable 473 is formed in a dimension (length) that does not restrict the rotation of the throttle lever 390 when the throttle lever 390 is rotated when the mode switching lever 340 is in a position other than the lever position S.
- the mode switching lever side arm 471 When the mode switching lever 340 is switched to the lever position S, the mode switching lever side arm 471 also rotates in conjunction with the rotation of the mode switching lever 340. As the mode switching lever side arm 471 rotates, the other end of the throttle lever side arm 472 is pulled forward via the cable 473. That is, when the throttle lever 390 is at the lever position X and the mode switching lever 340 is switched to the lever position S, the throttle lever 390 is rotated backward by the cable 473 by a predetermined rotation angle. In this case, if the throttle lever 390 is to be rotated forward, the rotation of the throttle lever side arm 472 is restricted by the cable 473, so that the throttle lever 390 cannot be rotated to the lever position X. Thus, the engine speed can be limited to a predetermined value or less.
- the engine speed limiting means according to the present invention is not limited to the configuration of the throttle lever limiting mechanism 450, 460, 470 described above. That is, any configuration may be used as long as the engine speed can be limited to a predetermined value or less when the mode switching lever 340 is switched to the lever position S.
- the present invention can be used in the technology of work vehicles equipped with two or more hydraulic pumps.
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Abstract
Description
前記作業車両の油圧回路は、図14に示すようなローダ用コントロールバルブ500を具備する。
また、PTO用切換弁540の切換操作を行うことにより、前記一方の油圧ポンプにより圧送された作動油を、PTO用ポート560・561を介して取り出すことができる。当該取り出された作動油を用いて、作業車両に接続される他の作業装置を駆動することができる。
さらに、他方の油圧ポンプ(不図示)により圧送される作動油は、配管537・564を経てローダ用コントロールバルブ500の下流側に配置されるバックホー用コントロールバルブ(不図示)に供給される。前記他方の油圧ポンプにより供給される作動油と、前記一方の油圧ポンプにより圧送され、ローダ用コントロールバルブ500、キャリーオーバポート553、及び配管563を経て前記バックホー用コントロールバルブに供給される作動油と、により、図示せぬバックホーが駆動される。
6 エンジン
3 ローダ
4 バックホー
120 リザーバタンク(タンク)
150 バックホー用コントロールバルブ(他のコントロールバルブ)
200 ローダ用コントロールバルブ(コントロールバルブ)
230 モード切換弁
240 PTO用切換弁
260 PTO用ポート
261 PTO用ポート
344 カム部
364 カム部
380 リミットスイッチ(始動禁止手段)
400 インターロック機構
450 スロットルレバー制限機構(エンジン回転数制限手段)
460 スロットルレバー制限機構(エンジン回転数制限手段)
470 スロットルレバー制限機構(エンジン回転数制限手段)
図1に示すように、作業車両1は、作業装置を用いて土砂の運搬作業や掘削作業等を行うものである。作業車両1は、主として走行車両2、ローダ3、バックホー4等を具備する。
作業車両1は、バケットリフトアーム15・15及びローダバケット16の回動動作を組み合わせることにより、土砂等の運搬作業を行う。
スイングシリンダ23・23は、バックホー操作装置13によって伸縮制御可能な油圧シリンダである。スイングシリンダ23・23は、それぞれ機体フレーム5及びブームブラケット22の左右両側に具備される。スイングシリンダ23・23の一端は、それぞれ機体フレーム5の後端部に左右回動可能に支持される。スイングシリンダ23・23の他端は、それぞれブームブラケット22の前端に左右回動可能に支持される。
ブームシリンダ25は、バックホー操作装置13によって伸縮制御可能な油圧シリンダである。ブームシリンダ25の一端は、ブームブラケット22の後端上部に上下回動可能に支持される。ブームシリンダ25の他端は、ブーム24の中途部に上下回動可能に支持される。
アームシリンダ27は、バックホー操作装置13によって伸縮制御可能な油圧シリンダである。アームシリンダ27の一端は、ブーム24の中途部に上下回動可能に支持される。アームシリンダ27の他端は、アーム26の一端に上下回動可能に支持される。
バケットシリンダ29は、バックホー操作装置13によって伸縮制御可能な油圧シリンダである。バケットシリンダ29の一端は、アーム26の中途部に上下回動可能に支持される。バケットシリンダ29の他端は、バケット28に上下回動可能に支持される。
また、スイングシリンダ23・23を伸縮させることにより、ブームブラケット22を左右に回動させることができる。ブームシリンダ25を伸縮させることにより、ブーム24を上下に回動させることができる。アームシリンダ27を伸縮させることにより、アーム26を、ブーム24に対して上下に回動させることができる。バケットシリンダ29を伸縮させることにより、バケット28を、アーム26に対して上下に回動させることができる。作業車両1は、ブームブラケット22、ブーム24、アーム26、及びバケット28の回動動作を組み合わせることにより、土砂等の掘削作業を行う。
配管121は、リザーバタンク120と、油圧ポンプセクション130のポート131と、を接続する配管である。油圧ポンプセクション130は、リザーバタンク120内の作動油を配管121及びポート131を介して吸入し、吐出口132・133・134より吐出する。
配管135は、油圧ポンプセクション130の吐出口134と、パワーステアリング用バルブセクション140のポート142と、を接続する配管である。パワーステアリング用バルブセクション140は、吐出口134及び配管135を介して供給される作動油を用いて、ステアリングシリンダ141の動作を制御する。
配管136は、油圧ポンプセクション130の吐出口133と、ローダ用コントロールバルブ200のポンプポート251と、を接続する配管である。
配管137は、油圧ポンプセクション130の吐出口132と、ローダ用コントロールバルブ200のポート258と、を接続する配管である。
配管262は、ローダ用コントロールバルブ200のタンクポート252と、リザーバタンク120と、を接続する配管である。
配管264は、ローダ用コントロールバルブ200のポート259と、バックホー用コントロールバルブ150のポート152と、を接続する配管である。
バックホー用コントロールバルブ150は、配管264及びポート152を介して供給される作動油を用いて、スタビライザシリンダ21、バケットシリンダ29、及びブームシリンダ25の動作を制御する。
油路271は、油路270と油路272とを接続する油路である。油路271の中途部には、リリーフ弁271aが具備される。
油路272は、タンクポート252と接続される油路である。
油路273は、ダンプシリンダ用切換弁210と油路274の中途部とを接続する油路である。
油路274は、ダンプシリンダ用ポート254と油路272とを接続する油路である。油路274の中途部であって、油路274と油路272との接続部近傍には、アンチボイド付リリーフ弁274aが具備される。
油路275は、ダンプシリンダ用切換弁210と油路276の中途部とを接続する油路である。
油路276は、ダンプシリンダ用ポート255と油路272とを接続する油路である。油路276の中途部であって、油路276と油路272との接続部近傍には、アンチボイド付リリーフ弁276aが具備される。
配管266は、ダンプシリンダ用ポート255とダンプシリンダ18・18のロッド室とを接続する配管である。
ダンプシリンダ用切換弁210をポジションCに切り換えることにより、作動油は、油路273、油路274、ダンプシリンダ用ポート254、及び配管265を経て、ダンプシリンダ18・18のボトム室へと圧送される。これによって、ダンプシリンダ18・18を伸長させることができる。
また、ダンプシリンダ用切換弁210をポジションBに切り換えることにより、作動油は、油路275、油路276、ダンプシリンダ用ポート255、及び配管266を経て、ダンプシリンダ18・18のロッド室へと圧送される。これによって、ダンプシリンダ18・18を短縮させることができる。
このように、ダンプシリンダ用切換弁210のポジションを切り換えることで、ダンプシリンダ18・18を伸縮させることができる。これによって、ローダバケット16を、バケットリフトアーム15・15に対して上下に回動させることができる。
油路278は、バケットリフトシリンダ用切換弁220と油路279の中途部とを接続する油路である。
油路279は、バケットリフトシリンダ用ポート256と油路272とを接続する油路である。油路279の中途部であって、油路279と油路272との接続部近傍には、チェック弁279aが具備される。
油路280は、バケットリフトシリンダ用切換弁220とバケットリフトシリンダ用ポート257とを接続する油路である。
配管268は、バケットリフトシリンダ用ポート257とバケットリフトシリンダ17・17のボトム室とを接続する配管である。
バケットリフトシリンダ用切換弁220をポジションEに切り換えることにより、作動油は、油路280、バケットリフトシリンダ用ポート257、及び配管268を経て、バケットリフトシリンダ17・17のボトム室へと圧送される。これによって、バケットリフトシリンダ17・17を伸長させることができる。
バケットリフトシリンダ用切換弁220をポジションFに切り換えることにより、作動油は、油路278、油路279、バケットリフトシリンダ用ポート256、及び配管267を経て、バケットリフトシリンダ17・17のロッド室へと圧送される。これによって、バケットリフトシリンダ17・17を短縮させることができる。
このように、バケットリフトシリンダ用切換弁220を切り換えることで、バケットリフトシリンダ17・17を伸縮させることができる。これによって、バケットリフトアーム15を上下に昇降させることができる。
モード切換弁230は、ポート230aとポート230cとを連通し、ポート230dとポート230eとを連通し、ポート230bを閉塞する「作業ポジションH」と、ポート230a、ポート230b、ポート230c、ポート230d、及びポート230eを連通する「戻しポジションJ」と、ポート230aとポート230c・230dとを連通し、ポート230bとポート230eとを連通する「合流ポジションK」と、を切り換えることが可能である。
モード切換弁230のポジションは、ローダ等操作装置300に具備されるモード切換レバー340を操作することにより、切り換えることが可能である。
スプリング231・231は、モード切換弁230のポジションを、作業ポジションHに保持するものである。なお、本実施例においては、モード切換弁230はスプリング231・231を具備するものとするが、本発明はこれに限らず、モード切換弁230はスプリング231・231を具備しない構成とすることも可能である。
デテント機構232は、モード切換弁230のポジションを、戻しポジションJまたは合流ポジションKに保持するものである。モード切換弁230が戻しポジションJまたは合流ポジションKに切り換えられた場合、デテント機構232により、モード切換弁230が当該戻しポジションJまたは合流ポジションKに保持される。また、デテント機構232の保持力以上の操作力でモード切換レバー340を操作することにより、モード切換弁230を他のポジションに切り換えることができる。
油路282は、モード切換弁230のポート230bと油路272(ひいてはリザーバタンク120)とを接続する油路である。
油路283は、モード切換弁230のポート230dとポート258(ひいては前記油圧ポンプの吐出口132)とを接続する油路である。
油路284は、モード切換弁230のポート230eと油路285の中途部(ひいてはバックホー用コントロールバルブ150のポート152)とを接続する油路である。
油路285は、油路272とポート259とを接続する油路である。油路285の中途部であって、油路285と油路272との接続部近傍には、アンチボイド付リリーフ弁285aが具備される。
PTO用切換弁240は、ポート240aとポート240dとを連通し、ポート240b・240c・240e・240fを閉塞する「ポジションL」と、ポート240bとポート240fとを連通し、ポート240cとポート240eとを連通し、ポート240a・240dを閉塞する「ポジションM」と、ポート240bとポート240eとを連通し、ポート240cとポート240fとを連通し、ポート240a・240dを閉塞する「ポジションN」と、ポート240bとポート240eとを連通し、ポート240cとポート240fとを連通し、ポート240a・240dを閉塞する「連続ポジションP」と、を切り換えることが可能である。
PTO用切換弁240のポジションは、ローダ等操作装置300に具備されるPTO切換レバー360を操作することにより、切り換えることが可能である。
スプリング241・241は、PTO用切換弁240のポジションを、ポジションLに保持するものである。
デテント機構242は、PTO用切換弁240のポジションを、連続ポジションPに保持するものである。PTO用切換弁240が連続ポジションPに切り換えられた場合、デテント機構242により、PTO用切換弁240が当該連続ポジションPに保持される。また、デテント機構242の保持力以上の操作力でPTO切換レバー360を操作することにより、PTO用切換弁240を他のポジションに切り換えることができる。
油路287は、油路286の中途部とPTO用切換弁240のポート240bとを接続する油路である。油路287の中途部には、チェック弁287aが具備される。
油路288は、PTO用切換弁240のポート240cと油路272とを接続する油路である。
油路289は、PTO用切換弁240のポート240dとキャリーオーバポート253とを接続する油路である。
油路290は、PTO用切換弁240のポート240eと油路291とを接続する油路である。
油路291は、PTO用ポート260と油路272とを接続する油路である。油路291の中途部であって、油路291と油路272との接続部近傍には、プラグ291aが具備される。必要な場合には、プラグ291aに代えて、リリーフ弁等を介装する構成とすることも可能である。
油路292は、PTO用切換弁240のポート240fと油路293の中途部とを接続する油路である。
油路293は、PTO用ポート261と油路272とを接続する油路である。油路293の中途部であって、油路293と油路272との接続部近傍には、プラグ293aが具備される。必要な場合には、プラグ293aに代えて、リリーフ弁等を介装する構成とすることも可能である。
吐出口132(図2参照)より吐出された作動油は、配管137、ポート258、油路283、モード切換弁230、油路284、油路285、ポート259、及び配管264を経て、バックホー用コントロールバルブ150(図2参照)へと圧送される。
上記の如く、吐出口132・133より圧送される作動油を、それぞれバックホー用コントロールバルブ150へと圧送することができる。当該圧送された作動油により、バックホー4が駆動される。
吐出口132(図2参照)より吐出された作動油は、配管137、ポート258、及び油路283を経て、モード切換弁230へと圧送される。
吐出口132・133より吐出され、モード切換弁230へ圧送された作動油は、油路282、油路272、タンクポート252、及び配管262を経て、リザーバタンク120(図2参照)へと戻される。
また、エンジン6を始動させる際に、モード切換弁230を戻しポジションJに切り換えることにより、配管による圧損を低減し、エンジン6の始動性を向上させることができる。これによって、外気が低温である使用環境においても、良好なエンジン6の始動性を得ることができる。
吐出口132(図2参照)より吐出された作動油は、配管137、ポート258、及び油路283を経て、モード切換弁230へと圧送される。
吐出口132・133より吐出され、モード切換弁230へ圧送された作動油は、モード切換弁230内で合流される。当該合流された作動油は、油路286・287、PTO用切換弁240、油路290、油路291、及びPTO用ポート260を経て、前記接続された作業装置へと圧送される。
作動油を圧送する互いに独立した2つの油圧ポンプと、
前記2つの油圧ポンプにより圧送される作動油を合流する合流ポジションKに切り換え可能なモード切換弁230と、
作動油を取り出すPTO用ポート260・261と、
モード切換弁230の下流側に配置され、作動油をPTO用ポート260・261へ圧送可能に切り換えるPTO用切換弁240と、
を具備するものである。
このような構成において、モード切換弁230を合流ポジションKに切り換えることにより、吐出口132及び吐出口133より吐出される作動油を、合流させることができる。当該合流された作動油を用いることにより、吐出口132または吐出口133より吐出される作動油のみでは駆動させることができないような、大流量を必要とする作業装置を駆動させることができる。これによって、例えば、スキッドステア用の大流量を必要とする作業装置を、作業車両1で駆動させることが可能となる。
PTO用切換弁240を具備するローダ用コントロールバルブ200に一体的に設けられるものである。
このように構成することにより、モード切換弁230を配置するためのスペースを別途確保する必要が無く、省スペース化を図ることができる。さらに、モード切換弁230とローダ用コントロールバルブ200とを接続するための配管も不要であるため、部品点数及びコストの削減を図ることができる。
なお、本発明はこのような構成に限るものではなく、モード切換弁230を、ローダ用コントロールバルブ200と別体で構成することも可能である。
さらに、本実施形態の如く構成されたローダ用コントロールバルブを用いることにより、作業車両1が具備する油圧回路100の配管構成を簡素化することができる。具体的には、図14に示す配管537と配管564との接続部537aに必要な三方向継手が不要となる。これによって、油圧回路100の配管構成を簡素化し、部品点数の削減や組み立て工数の削減を図ることができる。
合流ポジションKと、
前記2つの油圧ポンプにより圧送される作動油をリザーバタンク120へ戻す戻しポジションJと、
前記2つの油圧ポンプにより圧送される作動油を合流することなく、それぞれ下流側に配置されるバックホー用コントロールバルブ150へと圧送する作業ポジションHと、
を切り換え可能に構成されるものである。
このように構成することにより、モード切換弁230を戻しポジションJに切り換えることで、作動油を短い経路でリザーバタンク120へと戻すことができる。これによって、油圧回路100の配管等による圧損を低減することができる。また、合流ポジションKと、戻しポジションJ及び作業ポジションHと、を同一の弁に設けることにより、別途弁を配置するためのスペースを確保する必要がなく、省スペース化を図ることができる。さらに、前記複数のポジションを一体の弁に設けることにより、部品点数及びコストの削減を図ることができる。
作動油をPTO用ポート260・261へ圧送可能に切り換えられた状態で保持される連続ポジションPを具備し、
PTO用切換弁240が連続ポジションPに切り換えられている場合にのみ、モード切換弁230を合流ポジションKに切り換え可能とするインターロック機構400を具備するものである。
このように構成することにより、作業車両1の安全性を向上させることができる。
具体的には、仮にPTO用切換弁240がポジションLにある場合に、モード切換弁230が合流ポジションKに切り換えられた場合、モード切換弁230内で合流された作動油が、油路286、PTO用切換弁240、油路289、キャリーオーバポート253、配管263、及びポート151を経て、バックホー用コントロールバルブ150へと圧送される。一方、ポート152からは、バックホー用コントロールバルブ150に作動油は供給されない。
この場合、ポート151より供給された作動油により、図2に示すスタビライザシリンダ21、スイングシリンダ23・23、及びアームシリンダ27が高速で作動し、スタビライザシリンダ21、バケットシリンダ29、及びブームシリンダ25が全く作動しない状態(以下、この状態を、単に「誤作動状態」と記す)となる。この誤作動状態においてバックホー4を操作した場合、当該バックホー4が、オペレータの意に反する動きをする場合がある。このようなオペレータの意に反する動きにより、作業車両1の姿勢が不安定になる等の不具合が生じるおそれがある。
インターロック機構400により、PTO用切換弁240が連続ポジションPの場合にのみ、モード切換弁230を合流ポジションKに切り換え可能な構成とすることで、モード切換弁230によって合流された作動油がバックホー用コントロールバルブ150に供給されることを防止することができる。これによって、上記の如き誤作動状態を予め防止し、作業車両1の安全性を向上させることができる。
ローダ等操作装置300は、主としてローダ用コントロールバルブ200、ローダ操作レバー310、ダンプ用リンク機構320、バケット用リンク機構330、モード切換レバー340、モード切換用リンク機構350、PTO切換レバー360、PTO用リンク機構370、リミットスイッチ380、スロットルレバー390等を具備する。
ローダ操作レバー310を左右に操作することにより、ダンプシリンダ用切換弁210のポジションを切り換えることができる。
ローダ操作レバー310を前後に操作することにより、バケットリフトシリンダ用切換弁220のポジションを切り換えることができる。
リミットスイッチ380の作動片381が押圧された場合、エンジン6を始動させるセルモータ(不図示)の駆動を禁止することができる。すなわち、リミットスイッチ380の作動片381が押圧されている間は、エンジン6を始動させることができない。
以下では、図5から図9までを用いて、インターロック機構400の動作態様について説明する。
なお、以下では、説明の便宜上、モード切換弁230が作業ポジションHにある場合のモード切換レバー340のポジションをレバーポジションQと、戻しポジションJにある場合のモード切換レバー340のポジションをレバーポジションRと、合流ポジションKにある場合のモード切換レバー340のポジションをレバーポジションSと、それぞれ定義する。
また、PTO用切換弁240がポジションL・M・N及び連続ポジションPにある場合のPTO切換レバー360のポジションをレバーポジションT・U・V・Wと、それぞれ定義する。
図5から図9では、上記レバーポジションの符号と合わせて、当該レバーポジションに対応するモード切換弁230及びPTO用切換弁240のポジションの符号を括弧内に図示する。
PTO切換レバー360を、レバーポジションUまたはレバーポジションVに切り換えた場合も上記と同様に、モード切換レバー340のレバーポジションSへの回動が制限される。これによって、モード切換レバー340をレバーポジションSに切り換えることができない。つまり、モード切換弁230を、合流ポジションKに切り換えることができない。
このように構成することにより、PTO用切換弁240が連続ポジションPにある場合は、エンジン6を始動させることができない。すなわち、エンジン6の始動と同時に、PTO用ポート260・261に接続された作業装置が駆動開始することを防止することができる。これによって、前記作業装置のメンテナンス時等において、エンジン6の始動と同時に前記作業装置が駆動することを防止し、メンテナンス作業等の安全性を向上させることができる。
なお、本実施形態において、本発明に係る始動禁止手段をリミットスイッチ380により構成するものとしたが、本発明はこれに限るものではない。すなわち、前記始動禁止手段は、PTO用切換弁240が連続ポジションPに切り換えられていることを検出し、エンジン6の始動を禁止することができる構成であればよい。
PTO用切換弁240が連続ポジションPからその他のポジションL・M・Nへと切り換えられた場合、モード切換弁230を合流ポジションKからその他のポジション(作業ポジションHまたは戻しポジションJ)へと切り換えるものである。
このように構成することにより、バックホー4が誤作動状態となることを未然に防止することができ、安全性を向上させることができる。
PTO用切換弁240が連続ポジションPからその他のポジションL・M・Nへと切り換えられる途中において、モード切換弁230を、合流ポジションK以外のポジション(作業ポジションHまたは戻しポジションJ)を所定寸法だけ超えたポジションまで移動させるものである。
このように構成することにより、モード切換弁230を確実に作業ポジションHへと切り換えることができる。
モード切換レバー側リンク部材453は、略矩形板状の部材である。モード切換レバー側リンク部材453の一端側は、モード切換レバー側リンク部材452の他端側に固定される。モード切換レバー側リンク部材453の他端側には、その両面を連通する貫通孔453aが形成される。当該貫通孔453aには、モード切換レバー340の把持部342が挿通される。
スロットルレバー側リンク部材455は、略矩形板状の部材である。スロットルレバー側リンク部材455の一端側は、スロットルレバー側リンク部材454の他端側に固定される。スロットルレバー側リンク部材455の他端側には、その両面を連通する貫通孔455aが形成される。当該貫通孔455aは、その長手方向が前後方向と略一致する長孔である。当該貫通孔455aには、スロットルレバー390が挿通される。
モード切換レバー340がレバーポジションS以外のポジションにある場合、スロットルレバー390は、エンジン回転数が最小となるポジションから、最大となるポジション(以下、単に「レバーポジションX」と記す)まで、前後に回動可能である。スロットルレバー側リンク部材455の貫通孔455aは、モード切換レバー340がレバーポジションS以外のポジションにある場合においてスロットルレバー390が回動した際に、当該スロットルレバー390と接触しない形状に形成される。
この場合、スロットルレバー側リンク部材455の貫通孔455aも後方へと移動するため、スロットルレバー390の前方回動が制限される。すなわち、スロットルレバー390がレバーポジションXにある場合において、モード切換レバー340がレバーポジションSに切り換えられると、スロットルレバー390は、スロットルレバー側リンク部材455によって、所定回動角度だけ後方に回動される。
この場合において、スロットルレバー390を前方へ回動させようとすると、当該スロットルレバー390とスロットルレバー側リンク部材455の貫通孔455aの内周前端部とが当接するため、スロットルレバー390をレバーポジションXまで回動させることができない。これによって、エンジン回転数を所定の値以下に制限することができる。
モード切換弁230が合流ポジションKに切り換えられている場合において、エンジン回転数を所定の回転数以下に制限するスロットルレバー制限機構450を具備するものである。
このように構成することにより、モード切換レバー340がレバーポジションSにある場合、すなわちモード切換弁230が合流ポジションKにある場合、スロットルレバー390の回動を制限し、エンジン回転数を所定の値以下に制限することができる。これに伴い、油圧ポンプセクション130に具備される油圧ポンプによる作動油の吐出量を減少させることができる。これによって、モード切換弁230が合流ポジションKにある場合における、作動油の温度の上昇を抑制し、オーバーヒート等の異常の発生を防止することができる。
リンク部材461の一端側には、その両面を連通する貫通孔461aが形成される。当該貫通孔461aには、モード切換レバー340の把持部342が挿通される。
リンク部材461の他端側には、その両面を連通する貫通孔461bが形成される。当該貫通孔461bは、その長手方向が前後方向と略一致する長孔である。当該貫通孔461bには、スロットルレバー390が挿通される。
モード切換レバー340がレバーポジションS以外のポジションにある場合、スロットルレバー390は、エンジン回転数が最小となるポジションから、最大となるポジション(レバーポジションX)まで、前後に回動可能である。リンク部材461の貫通孔461bは、モード切換レバー340がレバーポジションS以外のポジションにある場合においてスロットルレバー390が回動した際に、当該スロットルレバー390と接触しない寸法に形成される。
この場合において、スロットルレバー390を前方へ回動させようとすると、当該スロットルレバー390とリンク部材461の貫通孔461bの内周前端とが当接するため、スロットルレバー390をレバーポジションXまで回動させることができない。これによって、エンジン回転数を所定の値以下に制限することができる。
モード切換レバー340がレバーポジションS以外のポジションにある場合、スロットルレバー390は、エンジン回転数が最小となるポジションから、最大となるポジション(レバーポジションX)まで、前後に回動可能である。ケーブル473は、モード切換レバー340がレバーポジションS以外のポジションにある場合においてスロットルレバー390が回動した際に、当該スロットルレバー390の回動を制限しない寸法(長さ)に形成される。
この場合において、スロットルレバー390を前方へ回動させようとすると、スロットルレバー側アーム472の回動がケーブル473により規制されるため、スロットルレバー390をレバーポジションXまで回動させることができない。これによって、エンジン回転数を所定の値以下に制限することができる。
Claims (8)
- 作動油を圧送する互いに独立した2つ以上の油圧ポンプと、
前記2つ以上の油圧ポンプにより圧送される作動油を合流する合流ポジションに切り換え可能なモード切換弁と、
作動油を取り出すPTO用ポートと、
前記モード切換弁の下流側に配置され、作動油を前記PTO用ポートへ圧送可能に切り換えるPTO用切換弁と、
を具備する作業車両。 - 前記モード切換弁は、
前記PTO用切換弁を具備するコントロールバルブに一体的に設けられる請求項1に記載の作業車両。 - 前記モード切換弁は、
前記合流ポジションと、
前記2つ以上の油圧ポンプにより圧送される作動油をタンクへ戻す戻しポジションと、
前記2つ以上の油圧ポンプにより圧送される作動油を合流することなく、それぞれ下流側に配置される他のコントロールバルブへと圧送する作業ポジションと、
を切り換え可能に構成される請求項1または請求項2に記載の作業車両。 - 前記PTO用切換弁は、
作動油を前記PTO用ポートへ圧送可能に切り換えられた状態で保持される連続ポジションを具備し、
前記PTO用切換弁が前記連続ポジションに切り換えられている場合にのみ、前記モード切換弁を前記合流ポジションに切り換え可能とするインターロック機構を具備する請求項3に記載の作業車両。 - 前記インターロック機構は、
前記PTO用切換弁が前記連続ポジションからその他のポジションへと切り換えられた場合、前記モード切換弁を前記合流ポジションからその他のポジションへと切り換える請求項4に記載の作業車両。 - 前記インターロック機構は、
前記PTO用切換弁が前記連続ポジションからその他のポジションへと切り換えられる途中において、前記モード切換弁を、前記合流ポジション以外のポジションを所定寸法だけ超えたポジションまで移動させる請求項5に記載の作業車両。 - 前記PTO用切換弁が前記連続ポジションに切り換えられている場合において、エンジンの始動を禁止する始動禁止手段を具備する請求項4から請求項6までのいずれか一項に記載の作業車両。
- 前記モード切換弁が前記合流ポジションに切り換えられている場合において、エンジンの回転数を所定の回転数以下に制限するエンジン回転数制限手段を具備する請求項1から請求項7までのいずれか一項に記載の作業車両。
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US13/061,678 US8713931B2 (en) | 2008-09-02 | 2009-08-05 | Hydraulic circuit for working machine |
CA 2735253 CA2735253C (en) | 2008-09-02 | 2009-08-05 | Hydraulic circuit for working machine |
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JP2008225257A JP5368752B2 (ja) | 2008-09-02 | 2008-09-02 | 作業車両の油圧回路 |
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US9890801B2 (en) * | 2013-03-22 | 2018-02-13 | Hitachi Construction Machinery Tierra Co., Ltd. | Hydraulic drive system for construction machine |
ES2944264T3 (es) * | 2014-10-29 | 2023-06-20 | Clark Equipment Co | Enlace mecánico para el control de una máquina motriz |
CN107002715B (zh) * | 2015-01-06 | 2019-08-13 | 住友重机械工业株式会社 | 挖土机 |
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- 2008-09-02 JP JP2008225257A patent/JP5368752B2/ja not_active Expired - Fee Related
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JPS62178631A (ja) * | 1986-01-31 | 1987-08-05 | Yutani Juko Kk | 油圧シヨベルの特殊アタツチメント回路 |
JP2005121043A (ja) * | 2003-10-14 | 2005-05-12 | Nabtesco Corp | 油圧回路及びその合流弁 |
JP2005351442A (ja) * | 2004-06-14 | 2005-12-22 | Hitachi Constr Mach Co Ltd | 建設機械のアタッチメント用流量切替弁装置 |
JP2006249882A (ja) * | 2005-03-14 | 2006-09-21 | Yanmar Co Ltd | 作業車両の油圧回路構造 |
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JP5368752B2 (ja) | 2013-12-18 |
US20110168283A1 (en) | 2011-07-14 |
JP2010060027A (ja) | 2010-03-18 |
US8713931B2 (en) | 2014-05-06 |
CA2735253A1 (en) | 2010-03-11 |
US20120048409A9 (en) | 2012-03-01 |
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