JPH1159211A - Arrangement structure of hydraulic device for farm tractor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To facilitate assembling of functional parts of a hydraulic device and improve maintenance performance by arranging a hydraulic casing on an upper side of a transmission case, and arranging a valve plate, on which the functional parts of the hydraulic pressure are concentratedly arranged, on the upper surface of the hydraulic casing. SOLUTION: In this device, a valve plate 12, on which functional parts of a hydraulic device are concentratedly arranged, are mounted on an upper surface of a hydraulic casing 1 arranged on an upper side of a transmission case M on a rear side of a machine body. Hydraulic parts in respect to hydraulic lifting are concentratedly arranged on a rear side of the machine body. A hydraulic pump 11 is arranged on a front side of the hydraulic casing 1. A selective control valve 14 is also arranged on the rear side of the machine body, which valve 14 is prepared by vertical sandwitch control valves for taking out hydraulic pressure to the outside.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a hydraulic device for a tractor for performing lifting and lowering, horizontal control, and the like of a working machine mounted on a rear part of an aircraft.

[0002]

2. Description of the Related Art Conventionally, in a working vehicle such as a tractor, for example, as shown in Japanese Utility Model Laid-Open Publication No. 55-45714, a hydraulic pump, a line filter, an electromagnetic position valve for controlling the lifting and lowering of a working machine, and horizontal control are performed. Hydraulic devices such as swing valves are arranged in different parts of the fuselage, and are functional components of these hydraulic devices.
A relief valve, a safety valve, a hydraulic pressure take-out port, and the like are also separately provided and arranged at various positions. In particular, the hydraulic pump is often arranged near the cylinder block of the engine or on the upper surface or side surface of the transmission case. Then, a plurality of control valves for taking out the hydraulic pressure to the outside, which constitute a selective control valve, are provided in plural, and are arranged in parallel in the plane direction.

[0003] A brake valve for controlling the operation of the brake device and a clutch valve for controlling the operation of the clutch device are provided with a check valve for opening and closing an oil passage of the clutch valve. The sealing surface was made of metal.

[0004]

However, as described above, if the various hydraulic devices and the functional components of these hydraulic devices were formed separately and arranged at different locations on the body, When assembling and maintaining the hydraulic device and the functional parts, the operation may be complicated. In addition, the length and the number of hydraulic pipes for connecting hydraulic devices and functional parts are increased and increased, so that pressure loss is increased and the piping configuration is complicated.

[0005] Further, since the seal surface of the check valve provided on the brake valve and the clutch valve is made of metal, depending on the processing accuracy of the seal surface, the pressure applied to the seal surface in the sealing direction is low. In some cases, leakage was caused due to insufficient sealing properties, and the sealing performance was unstable. In order to improve the sealing property, it is conceivable to attach an O-ring to the sealing surface. In order to perform, the fixing method was difficult. A method of coating the entire seal surface with rubber is also conceivable.In this case, however, the check valve is in a one-sided contact state due to the one-sided opening operation, resulting in low durability and an unstable sealing performance immediately. Had become.

[0006]

The problem to be solved by the present invention is as described above. Next, means for solving the problem will be described. That is, the arrangement structure of the hydraulic device of the agricultural tractor is such that the hydraulic case disposed above the transmission case at the rear of the body of the agricultural tractor, the valve plate mounted on the upper surface of the hydraulic case, and the valve plate are concentrated. And the functional components of the hydraulic device arranged.

[0007] The arrangement of the hydraulic device of the agricultural tractor includes a hydraulic component for controlling the lifting and lowering of the working machine, which is disposed centrally at the rear of the body of the agricultural tractor, and a hydraulic case disposed above the transmission case at the rear of the aircraft. And a hydraulic pump disposed in front of the hydraulic case.

[0008] Further, the arrangement structure of the hydraulic device of the agricultural tractor is such that the control valve for taking out the hydraulic pressure to the outside of the agricultural tractor body comprises a plurality of vertically stacked selective control valves arranged at the rear of the aircraft body. It is.

The arrangement of the hydraulic device of the agricultural tractor includes a valve for controlling operation of a brake device and a clutch device, a check valve for opening and closing an oil passage of the valve,
A convex elastic member formed by baking on the seal surface of the check valve.

[0010]

Next, an embodiment of the present invention will be described. 1 is an overall side view showing a tractor provided with the hydraulic device of the present invention, FIG. 2 is a plan view showing a rear part of the fuselage, FIG. 3 is a side view showing the same, FIG. 4 is a rear view showing the same, FIG. 5 is a plan view showing a valve plate , FIG. 6 is a side view showing an operation route of the clutch device, FIG. 7 is a side sectional view showing the clutch valve, FIG. 8 is a front view likewise, FIG. 9 is a side view showing an operation route of the brake device, and FIG. Side sectional view showing, FIG.
Is a front view, FIG. 12 is a side sectional view showing an opening / closing portion of the check valve, and FIG. 13 is a side view showing the check valve.

First, the overall configuration of the tractor of the present invention will be described with reference to FIG. A bonnet B is disposed at the front of the machine that suspends the front and rear wheels FW and RW in front and back, and the hood B incorporates an engine E. A steering handle ST is provided behind the hood B, and a seat SE is provided behind the steering handle ST. Then, the steering wheel ST and the seat SE
Are covered by the cabin CB. Below the steering wheel ST, a clutch pedal 41 for operating the clutch device and a brake pedal 47 for operating the brake device are provided.

A clutch housing CH is connected to the rear of the engine E, and a transmission case M is connected to the rear of the clutch housing CH.
To be driven. A hydraulic case 1 is mounted on the upper surface of the rear part of the transmission case M, and lift arms 2 are supported on both sides of the hydraulic case 1 so as to be vertically rotatable. An outer cylinder 5 is interposed between the lift arm 2 and a drawbar bracket 4 fixedly provided at the lower end of the transmission case M. The vertical movement of the lift arm 2 is caused by the expansion and contraction of the outer cylinder 5. Do.

From the rear end of the machine, a working machine mounting device 3 composed of a three-point link projects, and the lift arm 2
Is configured to be able to move up and down. A work machine such as a rotary can be mounted on the rear end of the work machine mounting device 3. Further, the driving force of the engine E is transmitted to a power take-out shaft P protruding from the rear end of the transmission case M to drive the power take-out shaft P to drive a work machine connected to the rear end of the machine body. I have.

Next, the configuration of various hydraulic devices arranged at the rear of the machine will be described. 2 to 4, a hydraulic case 1 is mounted on a rear upper surface of the transmission case M located at the rear of the machine body, and a hydraulic pump 11 is mounted on a front surface of the hydraulic case 1. The hydraulic pump 11
Is the main shaft 2 driven by the engine E
4 is driven by a drive gear fixed to the rear end. The hydraulic pumps 11 drive the respective hydraulic devices disposed at the rear of the machine. In this embodiment, the hydraulic pump 11 is configured as a tandem type hydraulic pump, but may be configured as a single type.

A swing valve 13 is disposed on one side of the hydraulic case 1 (in this embodiment, on the right side with respect to the machine body traveling direction), and is configured to perform horizontal control of a work machine mounted on the rear end of the machine body. The line filter 1 is located on one side of the transmission case M (in this embodiment, on the right side with respect to the aircraft traveling direction).
6. The hydraulic pump 1 is provided with the hydraulic pump 1 through the line filter 16 so that hydraulic oil from inside the transmission case M is provided.
One is trying to inhale.

A valve plate 12 is mounted on the upper surface of the hydraulic case 1, and a selective control valve 14 and an electromagnetic position valve 15 are provided on the upper surface of the valve plate 12. The electromagnetic position valve 15 controls the lifting / lowering operation of the lift arms 2. The selective control valve 14 is configured by stacking a plurality of control valves 14 a, 14 a. . Further, hydraulic oil is supplied to the valve plate 12 from the hydraulic pump 11 through a high-pressure pipe 21.

A supply port 30 through which hydraulic oil is supplied from the hydraulic pump 11 is provided on the front surface of the valve plate 12, and a selective control valve mounting seat 12a and an electromagnetic position valve mounting seat 12b are provided on the upper surface of the valve plate 12. Has formed. A relief valve 31 is provided in the valve plate 12, and an import port 35 for taking out hydraulic oil and an out port 2 for taking out hydraulic oil to the front loader when a front loader is mounted on the front of the machine body.
6 is provided. Further, a slow return valve 32, a stop valve 33, and a safety valve 34 for controlling expansion and contraction operations of the exterior cylinder 5 and the like for moving the lift arm 2 up and down.
Is provided in the valve plate 12. in this way,
The functional components of the hydraulic device are concentrated on the valve plate 12. The valve plate 12 can be provided with various functional components of the hydraulic device other than those shown in this embodiment.

As described above, the relief valve 31, the import 35 and the out port 26 for taking out the hydraulic oil, the slow return valve 32, the stop valve 33, and the safety valve 34.
A valve plate 12 in which functional components of various hydraulic devices such as the like are arranged in a concentrated manner, and the valve plate 12 is mounted on the upper surface of the hydraulic case 1 at the rear of the fuselage. Assembly is facilitated, and maintainability can be improved. Further, the hydraulic piping for connecting the functional components can be eliminated, and the cost can be reduced.

Hydraulic parts related to the hydraulic lift, such as the lift arm 2 for elevating and lowering the working machine, the exterior cylinder 5, and the electromagnetic position valve 15, are arranged in a concentrated manner at the rear of the machine, and above the transmission case M at the rear of the machine. By disposing the hydraulic pump 11 in front of the disposed hydraulic case 1, these hydraulic components can be easily assembled, maintenance is improved, and quality can be improved. Further, the number of hydraulic piping connecting each hydraulic component can be reduced and shortened, so that pressure loss can be reduced and cost can be reduced.

Further, the selective control valve 14 is formed by vertically stacking a plurality of control valves 14a for extracting hydraulic pressure to the outside, and the selective control valve 14 is disposed at a rear part of the body, so that the selective control valve 14 is assembled. Can be easily performed, and a hydraulic pipe connecting each control valve 14a can be eliminated, thereby improving maintainability. In addition, it is possible to easily assemble the work machines to be mounted at a site or the like.

Next, a clutch valve for controlling the operation of the clutch device will be described. In FIG. 6, a clutch valve 51 for controlling the operation of the clutch device is provided in front of a clutch pedal 41 configured to be rotatable around an upper end portion, and hydraulic oil is supplied from a hydraulic hose 46. When the clutch pedal 41 is depressed, the piston 52 of the clutch valve 51 is pushed into the clutch valve 51, and the hydraulic oil is fed through the hydraulic hose 42 to the clutch release cylinder 43 on the side of the clutch housing CH. As a result, the clutch release cylinder 43 operates, and the lower end of the clutch release shaft 44 rotates rearward, so that the traveling system clutch 45 disconnects the transmission of power.

7 and 8, the clutch valve 51
Is shown. A hydraulic hose 4 is provided in the clutch valve 51.
6, hydraulic fluid is supplied from the supply port 51a. Hydraulic oil supplied into the clutch valve 51 flows through the passage hole 53 a of the check sheet 53 through the clutch valve 5.
1 has entered the lower pressure chamber 51c. The pressure chamber 5
1c, a piston 52 is inserted from behind, and a locking pin 57 is inserted into a long hole 57 formed in the longitudinal direction of the upper surface of the piston 52, and the piston 52 is inserted into the long hole 52b.
Slidable in the front-rear direction within the range. The piston 52 is urged rearward by a spring 56, and the pressure chamber 51c communicates with a discharge port 51b formed below the clutch valve 51.

Further, the passage hole 5 of the check sheet 53
A check valve 54 is disposed at the lower end of the check valve 54, and the check valve 54 is urged upward by an urging member 55 so that a seal surface 54a formed at an upper end of the check valve 54 is connected to a lower end of the passage hole 53a. The passage hole 53a is configured to close and close the passage hole 53a. Further, at the tip of the piston 52, an engagement portion 52a protruding outward in the outer peripheral surface of the piston 52 is formed. When the piston 52 moves rearward, the engaging portion 52a engages with the lower end of the check valve 54, and the seal surface 54a of the check valve 54 moves downward with the rear end of the seal surface 54a as a fulcrum. The passage 53a is rotated so as to open. Also,
When the piston 52 moves forward to disengage the engagement portion 52a from the lower end of the check valve 54, the urging member 55
The sealing surface 54a is pivoted upward by the biasing force of the above to close the passage hole 53a. Although the clutch valve 51 in the present embodiment has one discharge port for discharging hydraulic oil, the clutch valve 51 may have a plurality of discharge ports.

The clutch valve 51 is configured as described above. In a normal state where the clutch pedal 41 is not depressed, the piston 52 is urged backward by the spring 56 to open the passage hole 53a of the check seat 53. The hydraulic oil supplied from the supply port 51a is
c. When the clutch pedal 41 is depressed, the piston 52 slides forward against the urging force of the spring 56 and the check valve 54
Pivots upward to close the passage hole 53a. Passage hole 53a
When the clutch pedal 41 is further depressed and the piston 52 is slid forward, the pressure of the hydraulic oil filled in the pressure chamber 51c increases, and the hydraulic oil is discharged from the discharge port 51b. Is done. The discharged hydraulic oil is pressure-fed to the clutch series cylinder 43 through the hydraulic hose 42 connected to the discharge port 51b, and the traveling system clutch 45 is disconnected.

Next, the brake valves for controlling the operation of the left and right brake devices will be described. In FIG. 9, a brake valve 6 for controlling the operation of a brake device is provided in front of a brake pedal 47 which is configured to be rotatable about an upper end portion.
1 is provided, and hydraulic oil is supplied from a hydraulic hose 49. When the brake pedal 47 is depressed, the piston 62 of the brake valve 61
The hydraulic oil supplied to the brake valve 61 and pushed into the brake valve 61 is sent to the left and right brake devices through hydraulic hoses 48 and 48 ′ connected to the brake valve 61. Thus, the left and right brake devices are operated.

10 and 11, the brake valve 61 is shown. The hydraulic hose 4 is provided in the brake valve 61.
9, hydraulic oil is supplied from the supply port 61a,
When the piston 62 is pushed into the brake valve 61, the hydraulic oil supplied into the brake valve 61
The discharge ports 61b and 61b 'are configured to be discharged. Hydraulic hoses 48, 48 'are connected to the discharge ports 61b, 61b', respectively.

First, a mechanism for discharging the hydraulic oil from the discharge port 61b will be described. The hydraulic oil supplied from the supply port 61a enters the pressure chamber 61c below the brake valve 61 through the passage hole 63a of the check sheet 63. The piston 62 is inserted into the pressure chamber portion 61c from the rear. A locking pin 67 is inserted into a long hole 67 formed in the longitudinal direction of the upper surface of the piston 62, and the piston 62
Is slidable in the front-rear direction within the range of the elongated hole 62b. The piston 62 is urged rearward by a spring 66, and the pressure chamber 61c communicates with a discharge port 61b formed below the brake valve 61.

The passage hole 6 of the check sheet 63
A check valve 64 is disposed at the lower end of the check valve 64. The check valve 64 is urged upward by an urging member 65 so that a seal surface 64a formed at the upper end of the check valve 64 is connected to the lower end of the passage hole 63a. The passage hole 63a is configured to close the passage hole 63a. Further, an engagement portion 62a protruding outward in the outer peripheral surface of the piston 62 is formed at the tip of the piston 62. When the piston 62 moves rearward, the engaging portion 62a engages with the lower end of the check valve 64, and the sealing surface 64a of the check valve 64 moves downward with the rear end of the sealing surface 64a as a fulcrum. The passage hole 63a is configured to rotate and open. Also,
When the piston 62 moves forward to disengage the engagement portion 62a from the lower end of the check valve 64, the urging member 65
The sealing surface 64a pivots upward by the biasing force of the above to close the passage hole 63a. Accordingly, similarly to the case where the hydraulic oil is discharged from the discharge port 51b of the clutch valve 51, when the piston 62 is pushed into the brake valve 61, the pressure of the hydraulic oil filled in the pressure chamber 61c increases. As a result, it is discharged from the discharge port 61b.

Further, the brake valve 6 is supplied from the supply port 61a.
As described above, the mechanism for discharging the hydraulic oil supplied to the inside 1 from the discharge port 61b 'is configured similarly to the mechanism for discharging the hydraulic oil from the discharge port 61b. When the hydraulic oil is discharged from the discharge port 61b and the discharge port 61b ', the operation of the equalizer 68 causes the two discharge ports 61b.
The pressure of the hydraulic oil discharged from 61b 'is configured to be equal. Although the brake valve 61 in the present embodiment is configured to have two discharge ports for discharging hydraulic oil, the brake valve 61 has one or more discharge ports, or
It may be configured to have three or more.

The clutch valve 51 constructed as described above
FIG. 12 shows the open / close portions of the check valve 54 and the check valve 64 of the brake valve 61. The check valve 54
64 is rotated up and down with the rear end as a fulcrum to open and close the passage holes 54a and 64a, and when the passage holes 54a and 64a are closed, the seal surfaces 54a and 64a of the check valves 54 and 64 The contact surfaces 53b and 63b formed at the lower ends of the passage holes 54a and 64a are in close contact with each other.

The sealing surfaces 54a and 64a are formed of a metal member, and the concave portions 54b and 64b are partially formed in the radial direction over the entire circumference in the circumferential direction of the portion in contact with the contact surfaces 53b and 63b. Is formed. The recesses 54b and 64b are filled with an elastic member 70 made of rubber or the like, and the elastic member 70 is formed by baking. On the upper surface of the elastic member 70, a lip portion 70a protruding upward is formed continuously in the circumferential direction. The sealing surface 5 is provided on the inner peripheral side of the lip 70a.
A groove 70b is formed which is recessed in the direction of the bottom surface of the recesses 54b and 64b rather than 4a and 64a. And the elastic member 7
The portion of the upper surface excluding the lip portion 70a and the groove portion 70b is formed in a substantially same or slightly depressed state as the sealing surfaces 54a and 64a.

When the pistons 52 and 62 move forward and the check valves 54 and 64 configured as described above are closed, first, the lip 70a of the elastic member 70 formed by baking on the sealing surfaces 54a and 64a, Passing holes 54a and 64a
It comes into contact with and comes into contact with the contact surfaces 53b at the lower end. In this case, even when the oil pressure in the pressure chambers 51c and 61c is low, the lip 70a is formed of an elastic member such as rubber, so that the passage holes 54a and 64a can be reliably sealed. Then, as the pistons 52 and 62 are further pushed in, the lip portion 70a is crushed as the oil pressure in the pressure chambers 51c and 61c increases, and at high pressure, the sealing surfaces 54a and 64 made of a metal member.
a contacts the contact surfaces 53b and 63b. That is, when the hydraulic oil in the pressure chambers 51c and 61c is in a high pressure state, both the elastic member 70 and the sealing surfaces 54a and 64a
The passage holes 54a and 64a can be more reliably sealed.

As described above, by forming the elastic member 70 on the sealing surfaces 54a and 64a made of a metal member by baking, when the operating oil in the pressure chambers 51c and 61c is in a low pressure state, the elastic member 70 is formed. Through hole 5 by the lip 70a of
4a and 64a can be reliably sealed, and when the hydraulic oil in the pressure chambers 51c and 61c is in a high pressure state, the passage holes 54a are more reliably formed in both the elastic member 70 and the sealing surfaces 54a and 64a. 64a can be sealed, and the sealing performance at low pressure and high pressure can be dramatically improved.

[0034]

As described above, the present invention has the following advantages. That is, as described in claim 1, the hydraulic case is disposed above the transmission case at the rear of the fuselage, and the valve plate on which the functional components of the hydraulic device are concentrated is placed on the upper surface of the hydraulic case. The assembly of the functional components of the hydraulic device was facilitated, and the maintainability was improved. Further, the hydraulic piping for connecting the functional components could be eliminated, and the cost could be reduced.

Further, hydraulic components related to a hydraulic lift for lifting and lowering the working machine mounted on the rear part of the machine body are centrally arranged at the rear part of the machine body, and are arranged above the transmission case at the rear part of the machine body. In front of the hydraulic case
The arrangement of the hydraulic pump facilitated the assembly of these hydraulic components, improved the maintainability, and improved the quality. In addition, the number of hydraulic piping connecting each hydraulic component can be reduced and shortened, so that pressure loss can be reduced and cost can be reduced.

Further, as described in claim 3, a selective control valve is formed by vertically stacking a plurality of control valves for taking out the hydraulic pressure to the outside, and the selective control valve is disposed at the rear part of the fuselage. The assembly of the valve 14 could be facilitated, the hydraulic piping connecting each control valve could be eliminated, and the maintainability could be improved. In addition, it has become possible to easily assemble work machines to be mounted at a site or the like.

Furthermore, an elastic member is attached to the seal surface of the brake valve for controlling the operation of the brake device and the seal surface of the check valve for opening and closing the oil passage of the clutch valve for controlling the operation of the clutch device. Because it formed
For example, when the hydraulic oil in the brake chamber and the pressure chamber in the clutch valve is in a low pressure state, the passage hole can be reliably sealed by the lip portion of the elastic member, and the hydraulic oil in the pressure chamber is in the high pressure state. In the case of, the passage hole can be more reliably sealed with both the elastic member and the sealing surface, and the sealing property of the oil passage at low pressure and high pressure,
In addition, the durability of the seal portion was dramatically improved.

[Brief description of the drawings]

FIG. 1 is an overall side view showing a tractor provided with a hydraulic device of the present invention.

FIG. 2 is a plan view showing a rear part of the fuselage.

FIG. 3 is a side view of the same.

FIG. 4 is a rear view of the same.

FIG. 5 is a plan view showing a valve plate.

FIG. 6 is a side view showing an operation path of the clutch device.

FIG. 7 is a side sectional view showing a clutch valve.

FIG. 8 is a front view of the same.

FIG. 9 is a side view showing an operation path of the brake device.

FIG. 10 is a side sectional view showing a brake valve.

FIG. 11 is a front view of the same.

FIG. 12 is a side sectional view showing an opening / closing portion of a check valve.

FIG. 13 is a side view showing a check valve.

[Explanation of symbols]

 E Engine M Transmission case CB Cabin CH Clutch housing FW Front wheel RW Rear wheel ST Steering handle 1 Hydraulic case 2 Lift arm 5 Exterior cylinder 11 Hydraulic pump 12 Valve plate 12a Selective control valve mounting seat 12b Electromagnetic position valve mounting seat 13 Swing valve 14 Selective Control valve 15 Electromagnetic position valve 16 Line filter 30 Supply port 31 Relief valve 32 Slow return valve 33 Stop valve 34 Safety valve 35 Import 36 Out port 51 Clutch valve 51c / 61c Pressure chamber 52/62 Piston 52a / 62a Engagement part 53a · 63a passing hole 54 · 64 check valve 54a · 64a sealing surface 54b · 64b recess 70 elastic member 70a Lip 70b Groove

Claims (4)

[Claims] 1. An arrangement structure of a hydraulic device for an agricultural tractor, comprising: a hydraulic case disposed above a transmission case at a rear portion of a body of the agricultural tractor; a valve plate mounted on an upper surface of the hydraulic case; An arrangement structure of a hydraulic device for an agricultural tractor, comprising functional parts of a hydraulic device arranged centrally. 2. The arrangement structure of a hydraulic device for an agricultural tractor, comprising: a hydraulic component for controlling the lifting and lowering of a working machine, which is arranged centrally on the rear part of the fuselage of the agricultural tractor; and a hydraulic case arranged above the transmission case at the rear part of the agricultural tractor. And a hydraulic pump disposed in front of the hydraulic case. 3. The arrangement structure of a hydraulic device for an agricultural tractor, wherein a control valve for extracting hydraulic pressure to the outside of the aircraft body of the agricultural tractor includes a plurality of selective control valves stacked vertically and arranged at the rear of the aircraft body. The arrangement structure of the hydraulic device of the agricultural tractor, characterized by the following. 4. An arrangement structure of a hydraulic device of an agricultural tractor, wherein a valve for controlling operation of a brake device and a clutch device, a check valve for opening and closing an oil passage of the valve, and seizure on a seal surface of the check valve. An arrangement structure of a hydraulic device for an agricultural tractor, comprising a formed convex elastic member.