JPS5936973Y2 - Agricultural tractor top link hinge - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a top link hinge for pivotally supporting the top link on the rear surface of the tractor in a three-point link type work implement mounting device for an agricultural tractor.

As shown in FIG. 6, conventional top link hinges are often fixed to the rear surface of a hydraulic case that is placed on top of a transmission case.

However, tensile and compressive forces are repeatedly applied to the top link hinge due to the rotation of the work equipment via the top link, and in order to withstand this, the bolts of the vertical mounting body of the top link hinge are of course It was also necessary to increase the number of bolts needed to attach the hydraulic case to the transmission case to support it, and to use larger bolts.

In order to eliminate these drawbacks, this project integrates the hydraulic case with the transmission case, and in order to compensate for the narrow mounting surface of the top link hinge, a vertical mounting body and a horizontal mounting body are installed on the top link hinge. It is constructed so that it can be firmly attached by providing a body.

Furthermore, by making the structure vertically symmetrical with respect to the horizontal mounting body, it is an effective idea both in terms of assembly and in terms of vertically replacing parts.

The purpose of the present invention is as described above, and the structure of the present invention will be explained based on the structure of the embodiment shown in the attached drawings.

FIG. 1 is an overall side view of the agricultural tractor.

The engine 2 is placed inside the hood 1, and the engine 2
The front axle bracket 3 protrudes from the lower side surface.

A front differential case 4 is pivotally supported on the front axle bracket 3 via a center pin, and front wheels 5.5 are supported on both sides of the front differential case.

A front wheel drive shaft device 6 transmits power to the front wheel differential case 4 from a transmission case 8 through a clutch housing 7.

A clutch housing 7 is fixed to the rear end surface of the engine 2,
A transmission case 8 is fixed to the rear surface of the clutch housing 7 with a center plate 9 sandwiched therebetween.

A rear axle 10 is supported on a transmission case 8, and a rear wheel 11.
11 is installed on the rear axle 11.

The transmission case 8 integrally incorporates a hydraulic case, which has conventionally been installed on the upper part of the transmission case, and is not provided with a separate hydraulic case.

Only the portion of the lift arm 16 into which the lifting shaft 15 is fitted has a protruding portion 8a that protrudes.

A seat 18 is provided on the upper surface of the mission case 8, and a PTO shaft, a PTO shaft cover 14, a drawbar 20, and a three-point link type work machine mounting device are provided on the rear surface of the mission case 8.

The three-point link type work equipment mounting device is Top Link 130, War Link 12. The present invention relates to a top link hinge 21 for pivotally supporting the top link 13 to the rear of the tractor.

In the present invention, the top link hinge 21 is fixed to two perpendicular surfaces: the rear surface of the transmission case and the upper surface of the protrusion 8a perpendicular to the rear surface of the transmission case.

FIG. 7 shows the shape of the mission case 8. Unlike the conventional case, a hydraulic case is not provided separately, but a hydraulic device is built inside the upper part of the mission case.

The hydraulic system includes a directional control valve 25, a cylinder 26, a piston 24, a piston rod 23, a rod arm 22, a lift arm shaft 15, and the like.

The cylinder 26 is provided within the wall thickness of the transmission case 8.

There is no problem in placing the lift arm shaft 15 in a low position, but since the PTO transmission of the PTO shaft is built inside the rear end of the mission case 8, it is necessary to poke a part of the mission case 8 so that the rod arm 22 does not engage. The protrusion 8a is formed by the protrusion 8a.

The top link hinge 21 is fixed to the top and rear surfaces of this protrusion 8a.

FIG. 6 is a drawing showing the structure of a conventional top link hinge and hydraulic system.

Conventionally, a separate hydraulic case was fixed on the upper machined surface of the transmission case 8, and the top link hinge 21 was fixed to the rear part of the hydraulic case.

It is impossible to fix the top link hinge 21 across the joint surface of the hydraulic case and the transmission case because these two sides are not co-processed and there is a slight difference in alignment. It was attached only to the rear of the

As a result, the vertical mounting body 21b needs to have a wide mounting surface and is made of a thick material.

Figures 2 to 5 show the top link hinge 21 of the present invention.
The structure of is shown.

FIG. 2 is a side view, FIG. 3 is a plan view, FIG. 4 is a rear view, and FIG. 5 is a front view.

The top link hinge 21 fits between a pair of hinge bodies 21a, a vertical attachment body 21b, and a pair of horizontal attachment bodies 21c, and the horizontal attachment body 21c is provided at an intermediate position between the pin holes 21a of the hinge body 21a.

The top link hinge 21 is fixed to the mission case 8 through the bolt holes 21e of the horizontal mounting body 21c and the vertical mounting body 21.
This is done through the bolt hole 21f of b.

Either the upper two bolt holes or the lower two bolt holes 21f of the vertical mounting body 21b are used.

As described above, the present invention integrates the transmission case 8 and the hydraulic case, configures the pivot portion of the lift arm shaft 15 on the right-angled protrusion 8a configured above the rear of the transmission case, and forms the pivot portion of the lift arm shaft 15 on the rear and upper surfaces of the protrusion 8a. A top link hinge having a horizontal attachment body and a vertical attachment body is fixed to two sides of the top link hinge 21, and the top link hinge 21 is made to protrude above the protrusion 8a, and the pin hole 21d is positioned above the horizontal attachment body. Therefore, it has the following effects.

First of all, if the mission case 8 and the hydraulic case are integrated and made of cast metal, the wall thickness will be unified to the thickness of the mission case and will be thinner, and the overall thickness will be thinner than when the conventional hydraulic case is used alone. It becomes weaker in strength.

The main problem caused by this weak strength is the pivot portion of the lift arm shaft 15, which is easily cracked because the force of the hydraulic cylinder is directly applied to it.

According to the present invention, the right-angled surface of the protrusion, which is the pivot point of the lift arm shaft, can be protected by the top link hinge.

Also, because the transmission case 8 and the hydraulic case were integrated, the position of the hydraulic case was too low, and the top link's pivot pin hole had to be at a high position in relation to the work equipment as before. Since the top link hinge protrudes upward, the strength is weakened when the top link is pivotally supported at this portion, but this point can be compensated for by providing the horizontal mounting body 21c.

[Brief explanation of the drawing]

Figure 1 is an overall side view of the agricultural tractor, Figure 2 is a side view of the top link hinge, Figure 3 is a top view, Figure 4 is a rear view, Figure 5 is a front view, and Figure 6 is a side view of the top link hinge. FIG. 7 is a drawing showing a conventional top link hinge, and FIG. 7 is a drawing showing a transmission case of the present invention. 8...Mission case, 13...Top link, 16...Lift arm, 21...
...Top link hinge, 21a...Hinge body, 21b...Vertical mounting body, 21c...
...Horizontal mounting body.

Claims (1)

[Scope of utility model registration request] The transmission case 8 and the hydraulic case are integrated, a right-angled protrusion 8a formed above the rear of the transmission case is provided with a pivot portion for the lift arm shaft 15, and a horizontal mounting body is provided on two surfaces, the rear and top surfaces of the protrusion 8a. An agricultural tractor characterized in that a top link hinge having a vertical mounting body is fixed, the top link hinge 21 is made to protrude above the protruding part 8a, and the pin hole 21d is located above the horizontal mounting body. top link hinge.