JP2008148653A - Tractor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a tractor capable of ensuring the space above a cylinder case and reducing the cost. <P>SOLUTION: The tractor is equipped with a flow dividing valve for controlling the flow of an oil to a hydraulic cylinder apparatus for lifting and lowering an implement and a hydraulic cylinder apparatus 22 for controlling the tilt of the implement and a pilot check valve for regulating the flow of the oil to the own weight dropping direction of the hydraulic cylinder apparatus 22 for controlling the tilt of the implement and releasing the regulation during changeover to the direction installed in a block. Furthermore, the block is connected to solenoid proportional switching valves 57 and 60 for controlling the feeding and discharging of the hydraulic pressure from the hydraulic cylinder apparatus for lifting and lowering the implement together with the flow rate thereof, and an electromagnetic switching valve 70 for controlling the feeding and discharging of the hydraulic pressure from the hydraulic cylinder apparatus 22 for controlling the tilt of the implement. A valve assembly 80 for connecting the solenoid proportional switching valve 60 and the solenoid switching valve 70 to the block is mounted on the lateral side of the cylinder case 16. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a hydraulic cylinder device for lifting and lowering a work implement and a tractor including a hydraulic cylinder device for work implement tilt control.

  A hydraulic cylinder device is used for raising and lowering and tilting control of the working machine connected to the rear part. A flow divider valve and a rolling valve for controlling the operation of the hydraulic cylinder device for controlling the work implement inclination are arranged on one side of a cylinder case, and a main control for controlling the operation of the hydraulic cylinder device for raising and lowering the work implement. A tractor in which a valve is fixed to the other side surface of the cylinder case is known (for example, see Patent Document 1).

  In addition, as an arrangement structure of each valve for controlling the operation of each hydraulic cylinder device, a hydraulic cylinder device for raising and lowering the work implement disposed above the transmission case is provided above the transmission case provided with a seat above. A valve mounting part made up of a step-like recessed space so as to be positioned in front of the built-in cylinder case, and a plurality of hydraulic valves for working machine lifting / lowering and for working machine tilt control are integrally assembled A unit in which a unit is housed and mounted in the mounting portion is known (see, for example, Patent Document 2).

  In addition, a valve block consisting of a main valve for raising, an electromagnetic proportional valve, a main valve for lowering, an electromagnetic proportional valve, etc. that controls the operation of the hydraulic cylinder device for raising and lowering the work implement is fixed to the side of the cylinder case. A tilt control valve is integrally fixed to the rear side of the valve block and is arranged in a space formed at the rear of the seat (for example, see Patent Document 3).

JP-A-8-280206 (page 3, FIG. 2) Japanese Patent Laid-Open No. 11-178403 (page 3, FIG. 1) JP 2000-106711 A (page 3, FIG. 5)

  A flow divider valve and a rolling valve for controlling the operation of the hydraulic cylinder device for controlling the work implement inclination are arranged on one side of a cylinder case, and a main control for controlling the operation of the hydraulic cylinder device for raising and lowering the work implement. In the case where the valve is fixed on the other side of the cylinder case, a work such as routing a pipe connecting the hydraulic pressure source and each valve around the cylinder case is required. The space for arranging the members is not only tight, but also increases the cost.

  Formed on the upper part of the transmission case is a valve mounting portion made up of a stepped recess so as to be located in front of the cylinder case containing the hydraulic cylinder device for raising and lowering the work implement disposed at the upper part of the transmission case. In the case where a valve unit in which a plurality of hydraulic valves for working machine lifting / lowering and working machine tilt control are integrally assembled is accommodated in the mounting portion, the structure of the transmission case becomes complicated and the cost increases. It was a factor.

  A valve block configured by integrally providing a main valve for raising, an electromagnetic proportional valve, a main valve for lowering, an electromagnetic proportional valve, etc. for controlling the operation of the hydraulic cylinder device for raising and lowering the work implement is fixed to the side surface of the cylinder case. The tilt control valve is fixed to the rear side of the valve block and placed in the space formed at the rear of the seat, so it is placed in a narrow space such as an electromagnetic proportional switching valve. Becomes difficult.

  In view of the above circumstances, the present invention provides a tractor that can secure a space above the cylinder case, can afford a space for arranging other members such as a seat, and can reduce costs. The purpose is to provide.

In order to achieve the above object, the present invention according to claim 1 is arranged such that a cylinder case (16) for accommodating a hydraulic cylinder device (17) for raising and lowering a work implement is disposed at a rear portion of a traveling machine body (5), The piston of the hydraulic cylinder device (17) is connected to the left and right lift arms (18), and one of the left and right lift rods (21) connected to the lift arms (18) is connected to a hydraulic cylinder device for work implement tilt control. In the tractor formed by interposing (22),
A diverter valve (54) for controlling the flow of oil to the hydraulic cylinder device (17) for lifting and lowering the work implement and the hydraulic cylinder device (22) for tilt control of the work implement, and the hydraulic cylinder for controlling the work implement tilt A block (75) is provided with a pilot check valve (65) for restricting the flow of oil in the direction of falling the weight of the device (22) and releasing the restriction when switching to the direction,
The block (75) includes an electromagnetic proportional switching valve (57, 60) for controlling the supply and discharge of hydraulic pressure to and from the hydraulic cylinder device (17) for raising and lowering the work implement together with the flow rate, and the work implement tilt control. An electromagnetic switching valve (70) for controlling supply and discharge of hydraulic pressure to the hydraulic cylinder device (22),
A valve assembly (80) in which the electromagnetic proportional switching valve (57, 60) and the electromagnetic switching valve (70) are connected to the block (75) is attached to the side of the cylinder case (16).
The tractor is characterized by that.

In the present invention according to claim 2, the flow dividing valve (54) is disposed on the rear side of the block (75), and the pilot check valve (65) is disposed on the further rear side of the flow dividing valve (54).
The electromagnetic switching valve (70) is fixed to the rear part of the pilot check valve (65) of the block (75),
The electromagnetic proportional switching valve (57, 60) is fixed to the front upper part of the block (75).
A tractor according to claim 1.

  The reference numerals in the parentheses are for reference to the drawings and do not limit the present invention.

  According to the first aspect of the present invention, since the electromagnetic proportional switching valve and the electromagnetic switching valve are integrally connected to the block having the shunt valve and the pilot check valve, a single valve assembly is formed. All the valves that control the lifting and tilting of the machine can be combined into one compact configuration, and the valve assembly is attached to the side of the cylinder case that is equipped with a hydraulic cylinder device for lifting and lowering the work machine. A space can be secured above the space, and a space for arranging other members such as a seat can be afforded, and the cost can be reduced.

  According to the second aspect of the present invention, the pilot check valve is arranged at the rear part of the diversion valve, and further the electromagnetic switching valve is arranged at the rear side thereof, so that the piping (hose) to the hydraulic cylinder device for tilt control is short. In addition, the hose can be arranged from the vicinity of the fulcrum portion of the lift arm, and the hose can be arranged rationally and the hose can be easily replaced.

  In addition, since the electromagnetic proportional switching valve is arranged at the upper front portion of the block, the electromagnetic proportional switching valve can be easily maintained by approaching the electromagnetic proportional switching valve from above.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  1 to 5 show an embodiment of the present invention. FIG. 1 is a perspective view of a tractor, FIG. 2 is a hydraulic system diagram of the tractor, and FIG. 3 is a perspective view of a valve assembly in the hydraulic system. FIG. 4 is a perspective view showing an attached state of the valve assembly in the tractor, and FIG. 5 is a plan view showing an attached state of the valve assembly in the tractor.

  As shown in FIG. 1, the tractor 1 has a traveling machine body 5 supported by front wheels 2, 2 and a rear wheel 3 (3), and an engine (not shown) is mounted on the front part of the traveling machine body 5. And covered with a bonnet 6. A driver's seat 8 is formed above the central portion of the mission case 7 supported by the traveling machine body 5. The driver's seat 8 is provided with a steering handle 10 above the step 11 on which the driver gets on and a seat mounting frame 12 extending rearwardly from the step 11. Is supported.

  As shown in FIG. 4, at the rear part of the tractor 1, there is a hydraulic cylinder device 17 (see FIG. 2) for raising and lowering the work implement disposed in a cylinder case 16 fixed to the rear upper part of the transmission case 7. A pair of lift arms 18 that are slid by operation are arranged.

  One of the pair of lower links 20 whose one end is rotatably supported by the lower portion of the transmission case 7 is connected at the center to one of the lift arms 18 via a lift rod 21, and the other of the lower links 20. The central part is connected to a hydraulic cylinder device 22 for tilt control of the work implement. One end of the upper link 23 is rotatably supported on the rear upper part of the transmission case 7. The pair of lower links 20 and the upper links 23 constitute a three-point support mechanism.

  As shown in FIG. 1, a working machine 25 such as a rotary is connected to the tractor 1 through the three-point support mechanism. The working machine 25 is moved up and down between the standby position and the working position by the operation of the hydraulic cylinder device 17, and the working machine 25 is moved by the operation of the hydraulic cylinder device 22 even if the tractor 1 is inclined. Tilt control is performed so that a horizontal state can be maintained.

  The tractor 1 is provided with a hydraulic system for carrying out its traveling operation and controlling the lifting and tilting of the work machine 25.

  As shown in FIG. 2, the hydraulic system 30 of the tractor 1 includes a power steering pump 32 driven by a motor 31, and a hydraulic lift pump. The oil is stored in the transmission case 7 that also serves as an oil tank. 50 is pumped through the filter 33 and supplied to the required place.

  The pump 32 is connected to an auto brake turn system 35 of a hydraulic system and a front wheel steering system 45 through the auto brake turn system 35. The pump 50 is connected to a lift control system 55 of the work machine 25 and an inclination control system 65 of the work machine 25 via a diversion valve 54 via a hydraulic take-out block 51.

  The auto brake turn system 35 includes a hydraulic pressure switching valve 37 for a front wheel acceleration clutch, a hydraulic pressure switching valve 38 for an auto brake, and a relief valve 40 connected to the hydraulic pump 32 via a check valve 36. Yes. The hydraulic pressure switching valve 37 is connected to a front wheel speed increasing clutch 41, and the hydraulic pressure switching valve 38 is connected to left and right brake cylinders 42, 43.

  The front wheel steering system 45 includes a check valve 46 connected to the relief valve 40, a hydraulic switching valve 47 for switching the steering direction, and the like. A hydraulic cylinder 48 for steering is connected to the hydraulic pressure switching valve 47, and the hydraulic pressure switching valve 47 is driven by operating the handle 10 to operate the traveling direction of the tractor 1.

  A pump port P, a tank port T, and a neutral port N are formed in the hydraulic pressure take-out block 51, and a relief valve 52 is disposed therein.

  The elevation control system 55 is connected to the hydraulic pressure take-out block 51 via a filter 53 and the diversion valve 54, and includes a relief valve 56, an electromagnetic proportional switching valve 57, a raising main valve 58, an electromagnetic proportional switching valve 60, and a lowering side. A main valve 61 and the like are provided. The elevation control system 55 is connected to the hydraulic cylinder device 17 and controls the elevation of the work machine 25.

  The tilt control system 65 is connected to the flow dividing valve 54 and includes a pilot check valve 66, a check valve 67, a throttle valve 68 and an electromagnetic switching valve 70. The tilt control system 65 is connected to the hydraulic cylinder device 22 and controls the tilt of the work machine 25.

  As shown in FIG. 3, the elevation control system 55 and the tilt control system 65 are arranged such that the flow dividing valve 54 is disposed on the rear side of a block 75 in which a required oil passage is formed, and further on the rear side of the flow dividing valve 54. The pilot check valve 66 is disposed at the rear, the electromagnetic switching valve 70 is fixed to the rear portion of the pilot check valve 66, and the electromagnetic proportional switching valves 57 and 60 are fixed to the front upper part of the block 75, and integrated. A valve assembly 80 is configured.

  As shown in FIGS. 4 and 5, the valve assembly 80 is attached to the side surface of the cylinder case 16 so that the electromagnetic proportional switching valves 57 and 60 face the opening 12 a of the frame 12. A plate (not shown) covering the opening 12a can be detachably disposed on the frame 12 by means such as screws.

  As described above, by configuring one valve assembly 80, all the valves for controlling the raising and lowering and tilting of the working machine 25 can be integrated into a single compact configuration. Further, since the valve assembly 80 is attached to the side of the cylinder case 16 in which the hydraulic cylinder device 17 is housed, a space can be secured above the cylinder case 16, and therefore the seat 13 and the like can be secured. Space can be provided for the arrangement of other members, and costs can be reduced.

  Further, since the pilot check valve 66 is arranged at the rear part of the flow dividing valve 54 and the electromagnetic switching valve 70 is arranged at the rear side thereof, the pipe (hose) to the hydraulic cylinder device 22 for tilt control is short. In addition, the hose can be arranged from the vicinity of the fulcrum portion of the lift arm 18, and the hose can be easily routed and the hose can be easily replaced.

  Further, since the electromagnetic proportional switching valves 57 and 60 are disposed at the upper front part of the block 75, the electromagnetic proportional switching valves 57 and 60 are easily maintained by approaching the electromagnetic proportional switching valves 57 and 60 from above. be able to.

It is a perspective view of a tractor. It is a hydraulic system figure of a tractor. It is a perspective view of the valve assembly in a hydraulic system. It is a perspective view which shows the attachment state of the valve assembly in a tractor. It is a top view which shows the attachment state of the valve assembly in a tractor.

Explanation of symbols

5 Traveling Machine Body 16 Cylinder Case 17 Hydraulic Cylinder Device 18 Lift Arm 21 Lift Rod 22 Hydraulic Cylinder Device 54 Flow Dividing Valve 57 Electromagnetic Proportional Switching Valve 60 Electromagnetic Proportional Switching Valve 65 Pilot Check Valve 70 Electromagnetic Switching Valve 75 Block 80 Valve Assembly

Claims (2)

A cylinder case that houses a hydraulic cylinder device for raising and lowering the work implement is disposed at the rear of the traveling machine body, and the piston of the hydraulic cylinder device is connected to the left and right lift arms, and the left and right lift rods that are connected to the lift arms In either one of the tractors with a hydraulic cylinder device for work implement tilt control interposed,
A diverter valve for controlling the flow of oil to the hydraulic cylinder device for lifting and lowering the work implement and the hydraulic cylinder device for controlling the work implement tilt, and the oil in the direction of dropping the weight of the hydraulic cylinder device for controlling the work implement tilt. The block is equipped with a pilot check valve that regulates the flow and releases the regulation when switching in the direction,
The block includes an electromagnetic proportional switching valve that controls supply and discharge of hydraulic pressure to and from the hydraulic cylinder device for raising and lowering the work implement together with the flow rate, and supply and discharge of hydraulic pressure to the hydraulic cylinder device for work implement tilt control and the block. A solenoid switching valve to be controlled,
A valve assembly in which the electromagnetic proportional switching valve and the electromagnetic switching valve are connected to the block is attached to the side of the cylinder case.
A tractor characterized by that. The diversion valve is arranged on the rear side of the block, the pilot check valve is arranged on the further rear side of the diversion valve,
The electromagnetic switching valve is fixed to the rear of the pilot check valve of the block,
The electromagnetic proportional switching valve is fixed to the front upper part of the block,
The tractor according to claim 1.

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