JPH1189315A - Tractor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a tractor capable of preventing the generation of large vibrations and noises in a universal joint portion and simultaneously capable of eliminating a troublesome work for attaching a top link-attaching base to the body of the tractor. SOLUTION: In the outer hydraulic pressure-taking device of a tractor in which a hydraulic lift device 10 having a lift arm 9 is loaded on the rear upper surface of the body of the tractor, a top link-attaching base 87 is integrally disposed on the hydraulic housing of the hydraulic lift device 10. The hydraulic housing of the hydraulic lift device 10 and the top link-attaching base 87 may integrally be cast.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a tractor provided with a hydraulic lifting device having a lift arm.

[0002]

2. Description of the Related Art As shown in FIG. 13, a hydraulic lift device 202 having a lift arm 201 is mounted on a rear upper surface of a transmission case 204 of a tractor body 203 as shown in FIG.
6 and a pair of left and right lower links 207, a work implement 209 is connected via a three-point link mechanism 208, and the lower link 207 is connected to a lift arm 201 of a hydraulic lifting device 202 via a lift rod 210. The work implement 209 is attached to the rear of the tractor body 203 via the three-point link mechanism 208 so as to be able to move up and down, and the PTO shaft 212 of the tractor body 203 and the input shaft 213 of the work implement 209 are connected to the universal joint 214. And the power on the tractor body 203 side is
There is something that is transmitted to the side.

However, this type of conventional tractor has a top link mount 215 for connecting the top link 206 of the three-point link mechanism 208 to the tractor body 203,
The top link mounting base 215 is formed separately from the hydraulic housing 216 and the like constituting the hydraulic lifting device 202.
The tractor body 203 was attached to the rear surface of the transmission case 204 so as to protrude rearward.

[0004]

Therefore, in the conventional case,
For example, it is necessary to fasten and fix the top link mounting base 215 to the rear surface of the transmission case 204 of the tractor body 203 using bolts and nuts, and the work of mounting the top link mounting base 215 to the tractor body 203 is troublesome. Was. Further, since the position of the top link mounting base 215 is located below the hydraulic lifting / lowering device 202, the top link 206 is inclined upward and backward, and the top link 20 is tilted upward.
6 is largely deviated from the direction in which the lower link 207 is parallel to the lower link 207. Therefore, when the work implement 209 is lifted upward via the three-point link mechanism 208, the angle β1 formed by the PTO shaft 212 and the universal joint 214 and the input shaft 213 and the universal joint 214 make an angle β2 that is greatly different from each other, which causes large vibration and noise at the universal joint 214 that connects the PTO shaft 212 and the input shaft 213 of the work machine 209. There were also problems.

SUMMARY OF THE INVENTION In view of the above problems, the present invention prevents large vibration and noise from being generated in a universal joint portion connecting a PTO shaft and an input shaft of a working machine, and at the same time, mounts a top link mounting base to a tractor body. This eliminates the hassle of work.

[0006]

A first technical means of the present invention for solving this technical problem is that a lift arm 9 is provided.
In the tractor mounted on the rear upper surface of the tractor vehicle body 5 with the hydraulic lifting device 10 having the above, the top link mount 87 is provided integrally with the hydraulic housing 33 of the hydraulic lifting device 10.

A second technical means of the present invention resides in that the hydraulic housing 33 of the hydraulic elevating device 10 and the top link mount 87 are integrally formed by casting.
Therefore, it is not necessary to fasten the top link mounting base 87 to the tractor vehicle body 5 side by using a bolt nut or the like, and the work of mounting the top link mounting base 87 to the tractor vehicle body 5 is eliminated.

The tractor body 5 of the top link 16
The mounting position on the side is located above the transmission case 7, and as shown in FIG.
When the rotary work machine 12 is lifted up via the three-point link mechanism 11 because the top link 16 and the lower link 17 can be made substantially parallel so that
Angle β between TO shaft 19 and universal joint 21
1 and the angle β2 formed by the input shaft 20 and the universal joint 21 are substantially equal. As a result, large vibrations and noises are applied to the universal joint 21 connecting the PTO shaft 19 and the input shaft 20 of the rotary working machine 12. Will not occur.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. FIGS. 1 to 4 show a tractor of a two-shaft, four-wheel type. In the figure, the tractor has left and right front wheels and left and right rear wheels 4, and the front wheels are steerable wheels and can be driven. Here, a four-wheel drive tractor is used. Two-wheel drive (rear-wheel drive) can also be performed by connecting and disconnecting the power.

The tractor body 5 is constructed by connecting a transmission case 7 to a rear portion of a mounted engine via a clutch housing. An engine and an engine auxiliary device such as a radiator provided in front of the engine are provided with a top plate. It is covered with a hood that can be freely opened and closed. A hydraulic lifting device 10 having left and right lift arms 9 is mounted on the rear upper surface of the tractor body 5. As shown in FIGS. 8 and 12, a top link 16 shown in FIG. The rotary work machine 12 can be lifted and lowered by a three-point link mechanism 11 having the following.

The left and right rear wheels 4 are covered by rear wheel fenders 13 erected inside thereof, and a driver's seat 14 is disposed at the rear of the tractor body 5 and between the left and right rear fenders 13. ing. A steering handle 15 is provided in front of the driver's seat 14. The head portion 10A of the hydraulic lifting device 10 is covered from above by a floor seat 22, and a driver's seat 14 is mounted on the floor seat 22.

The tractor has a canopy (shade) 74 which is a low-pass, and the draft control valve device is mechanical (manual). A pair of right and left columns 75 of the canopy 74 are provided behind the driver's seat 14, and each pair of right and left columns 75 includes a lower column 75 </ b> A standing upright from the left and right rear axle housings 25 to near the upper surface of the fender 13. It is inserted into the upper part of the lower support 75A in a nested configuration so that it can be inserted and removed, and the bolt fastener 75C
And the upper support 75B mounted by the above. An external hydraulic take-out device 1 described below is provided between a pair of left and right columns 75 behind the driver's seat 14.

Referring to FIGS. 5 to 7, an external hydraulic take-out device 1 is mounted on a hydraulic elevating device 10 having left and right lift arms 9. A plurality of valves 35 for extracting hydraulic pressure are stacked. A hydraulic housing (hydraulic cylinder main body) 33 constituting the hydraulic elevating device 10 is provided with an oil passage 34 for taking out an external hydraulic pressure, and a valve 35 for taking out the external hydraulic pressure which is connected (communicated) to the oil passage 34 is provided. , Provided between the left and right lift arms 9 above the hydraulic housing 33.

More specifically, the hydraulic housing 33
Is made of a casting, and a mounting hole 36A for the transmission case 7 is formed in the pedestal portion 36, and the arm shaft 38 for the lift arm 9 is turned around the rear left and right walls of the main body portion 37 formed in the pedestal portion 36. Left and right bosses 39 are movably supported, and a cylinder tube 40 is provided in the front inside of the main body 37 so as to be inclined upward and forward. A piston is slidably fitted to the cylinder tube 40. The opening end of the tube 40 is closed by the head lid 41, and the pedestal portion 36 in a state where the hydraulic housing 33 covers the upper opening of the transmission case 7 is mounted detachably with vertical bolts. I have.

An inlet (main) port 42 for hydraulic oil from the hydraulic pump device 32 is formed on a side wall (right side wall in the figure) of the hydraulic housing 33.
Numeral 2 has a substantially threaded pipe configuration, and a pipe can be detachably connected to the port 42. The hydraulic housing 33 includes a draft control valve device 43 and a horizontal control valve device 4.
The oil passage 45 for these valve devices 43 and 44, the priority valve 4
6, while the relief valve 47 and the like are mounted,
When a front loader is mounted on the tractor, a hydraulic take-out port 48, a neutral port 49, a drain port 50, and the like for the loader are provided.

The draft control valve device 43 is an electromagnetic pilot valve in which an ascending and descending solenoid valve and a pilot switching valve are integrated, and receives signals from a draft sensor 51 and a lift arm sensor 52 as shown in FIG. The draft control is automatically enabled by a control signal from the control box 53.

The horizontal control valve device 44 transmits a signal of a rolling sensor 54 provided in the tractor body 5 shown in FIG.
The lift cylinder (lift rod) 55 is controlled by a signal from a stroke sensor 56 or the like. In FIG. 8, the control box 53 can be set and switched freely from a switch box 57 such as draft / horizontal control switching, draft control, and position control. Of course, the draft / position control can also be operated manually as described later. For this reason, a mounting hole for manual operation is opened on the right side of the hydraulic housing 33, and this opening is covered with a removable cover when automatic control (auto draft control) is performed.

The lift arm 9 is provided with a mounting hole 9A (see FIG. 1) for a telescopic hydraulic cylinder (assist cylinder) for lifting force (assisting hydraulic pressure enhancement). An outlet 58 is formed in the cylinder head 41, and a drop adjusting valve 59 is incorporated in the head 41. The valve 35 for taking out the external hydraulic pressure is configured by including a switching spool 62 in a valve case 61, and the spool 62 includes a swing arm 63.
Can be switched by the operating force of the push-pull cable 64 through the hydraulic pull-out unit (including the hydraulic pull-out and return) 3
5A is constituted by a quick coupler which makes the hydraulic take-out hose detachable substantially.

The valve 35 for taking out the external hydraulic pressure (including the valve case and the spool, the same applies hereinafter) can be directly mounted on the upper surface of the hydraulic housing 33 in communication with the oil passage 34. Connecting oil passage 6 communicating with passage 34
Hydraulic housing 3 with spacer 60 having
3 Removably mounted on the upper part. Also, the valve 35
May be mounted, but in the illustrated example, a plurality of them are vertically stacked via an intermediate spacer 65 and a head spacer 66, and are detachably mounted by bolts 67. At the rear, which makes it easy to attach and detach the hydraulic outlet hose.

Since the oil passage 34 for the valve 35 for taking out the hydraulic pressure is formed in the hydraulic housing 33,
No exposed piping is required, and when stacking the spacer 60 and the intermediate spacer (there is also an oil passage) 65, it is possible to reliably prevent oil leakage by ensuring the positioning and sealing of the overlapped surface. Since the lift arm 9 is provided between the left and right lift arms 9, the lifting operation of the lift arm 9 does not interfere with the hydraulic take-out hose.

As shown in FIG. 12, a rotary working machine is provided behind a tractor body 5 via a three-point link mechanism 11 having a top link 16 for connecting the rotary working machine 12 and a pair of left and right lower links 17. 12 and the lower link 17 thereof is connected to the lift arm 9 of the hydraulic lifting device 10 via the lift rod 18, whereby the lift arm 9 is swung upward. A rotary work machine 12 is mounted on the rear of the tractor body 5 so as to be able to move up and down. Also, the tractor body 5
PTO shaft 19 on the side and the input shaft 2 on the rotary work machine 12 side
And 0 by a universal joint 21,
The power of the tractor body 5 is transmitted to the rotary work machine 12.

As shown in FIGS. 5 and 6, the hydraulic housing 33 is provided with a top link mounting base 87 on its rear surface. The hydraulic housing 33 and the top link mounting base 87 are integrally formed by casting. The top link 16 is swingable about a left and right axis 91 via a torsion bar (a load sensing member, which is a draft sensor) 68, a top link mounting member 90 having a cylindrical body 88 and a pair of left and right brackets 89. Are linked.

Therefore, the top link mounting base is formed separately from the hydraulic housing 33 of the hydraulic elevating device 10 and is mounted on the rear surface of the transmission case 7 of the tractor body 5 in a rearwardly projecting manner. There is no need to tighten and fix the base 87 to the tractor body 5 using bolts and nuts, etc., so that the work of attaching the top link mounting base 87 to the tractor body 5 is eliminated, and the tractor body of the top link 16 is also eliminated. The mounting position on the fifth side is located at the upper side, and therefore, as shown in FIG. 12, the top link 16 approaches a horizontal state, and the top link 16 can be made substantially parallel to the lower link 17.
When the rotary working machine 12 is lifted upward through the three-point link mechanism 11 by swinging the lift arm 9 of the hydraulic lifting device 10 upward, an angle β1 formed between the PTO shaft 19 and the universal joint 21 is expressed by: Input shaft 20
Β2 formed between the PTO shaft 19 and the rotary work machine 1 are substantially equal to each other.
Universal joint 2 connecting the input shaft 20
It is possible to prevent large vibration and noise from being generated in one portion.

The tractor body 5 of the top link 16
Since the mounting position on the side is located above the transmission case 7, the rearward projecting amount of the top link mounting base 87 can be shortened. As a result, the rotary working machine 12 can be moved by the tractor body 5. The tractor, including the work implement, can be mounted closer to the tractor, so that the front-rear width of the entire tractor can be made shorter.

Further, since the oil supply plug A for supplying the operating oil to the transmission case 7 is provided, the valve 35 is mounted on one side in the left and right direction as shown in FIGS. Three-point link mechanism 1
When the actuator 1 is moved up and down, interference with the valve 35 is reduced, and as a result, the lift angle of the three-point link mechanism 11 (the left and right lift arms 9) is sufficiently ensured.

As shown in FIGS. 9 to 11, the valve 35 for taking out the external hydraulic pressure stacked on the hydraulic housing 33 is remotely controlled by a Bowden cable 64.
The remote control lever 76 is provided on the right side of the driver's seat 14 on the floor seat 22 via a horizontal pivot shaft 77. The remote control lever 76 has a window 102 formed on a step portion (rise surface) 22C of the floor seat 22. The lever 76 protrudes from the window 102.

A bracket 78 is bolted to the step 22C to reinforce the left and right sides of the window 102 of the step 22C. The bracket 78 is provided with a pivot 77,
The cylindrical portion 103 at the root of the lever 76 is rotatably fitted on the pivot shaft 77, and the arm portion 10 formed on the cylindrical portion 103 is formed.
4, a cable 64 is connected via a mounting pin 105 and a U-shaped bracket 79. The cable 64 extends from the right side above the hydraulic housing 33 to the left side, bypassing the rear of the driver's seat 14. ing.

The pivot shaft 77 is attached to the bracket 78 with the mounting hole 1.
06 and 107, and a fixing piece 108 protruding from one end of the pivot shaft 77 is fastened and fixed to the bracket 78 with a bolt nut 109, whereby the pivot shaft 77 is fixed to the bracket 78. ing. Both ends of the bracket 78 are respectively fastened and fixed to a pair of left and right mounting brackets 111 by bolt nuts 110, and the pair of mounting brackets 111 are tightened and fixed to the step 22 </ b> C of the floor sheet 22 by bolt nuts 112.

As shown in FIGS. 2 and 4, manual operation (manual operation) is performed instead of the automatic draft control device.
A hydraulic control lever device 80 is provided. The lever device 80 includes a position lever 81 and a draft lever 82, and has an opening formed on the right side of the hydraulic housing 33 (slightly behind the automatic draft control valve). A support arm 84 which inserts and supports a control shaft 83 having an inner / outer double shaft in a closed state is projected rightward and outward, and the control shaft 83 is rotated by front and rear operations of levers 81 and 82, It controls a valve provided in the hydraulic housing 33.

[0030]

According to the present invention, large vibration and noise can be prevented from being generated at the universal joint 21 connecting the PTO shaft 19 and the input shaft 20 of the work machine 12, and at the same time, the top link mounting base 87 Eliminating the work of attaching to the tractor body 5 is eliminated.

[Brief description of the drawings]

FIG. 1 is a side view of a tractor showing one embodiment of the present invention.

FIG. 2 is a side view of a rear portion of the tractor.

FIG. 3 is a plan view of a rear portion of the tractor.

FIG. 4 is a rear (rear) view of the tractor.

FIG. 5 is a side view of the hydraulic lifting device.

FIG. 6 is a plan view of the hydraulic lifting device.

FIG. 7 is a rear view of the hydraulic lifting device.

FIG. 8 is a configuration diagram of the hydraulic circuit.

FIG. 9 is a plan sectional view of a mounting portion of the operation lever.

FIG. 10 is a sectional view taken along line AA of FIG. 9;

FIG. 11 is a sectional view taken along the line BB of FIG. 9;

FIG. 12 is a schematic view of the three-point link portion.

FIG. 13 is a schematic view of a three-point link portion showing a conventional example.

[Explanation of symbols]

 2 Tractor 5 Tractor body 9 Lift arm 10 Hydraulic lifting device 14 Driver's seat 33 Hydraulic housing 87 Top link mount

Claims (2)

[Claims] 1. A tractor mounted on a rear upper surface of a tractor vehicle body (5) having a hydraulic lift device (10) having a lift arm (9), and a top link to a hydraulic housing (33) of the hydraulic lift device (10). An external hydraulic take-out device for a tractor, wherein a mounting base (87) is provided integrally. 2. The hydraulic housing (33) of the hydraulic lifting device (10) and the top link mount (87) are integrally formed by casting.
A tractor according to 1.