JPS5943122Y2 - Agricultural tractor drawbar hitch - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a drawbar hitch for a drawbar for towing a trailer or the like to the rear of an agricultural tractor.

There are various ways to attach a work implement to a tractor, but two types are provided at the rear of the tractor: a three-point link type work implement attachment device and a drawer device.

The three-point link type mounting device is equipped with a rotary tiller or the like that requires vertical movement, and the drawbar is equipped with a trailer or a large disc plow that can only be pulled.

The present invention aims to organically connect these two types of work machine mounting devices so that they can reinforce each other and serve the same purpose.
The lower link hinge, which is the pivot point of the lower ring, is made to protrude from the drawbar hitch bracket, so that the parts can be used for both purposes, thereby reducing the size.

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

Figure 1 is a side view of the rear half of the agricultural tractor.

A rear axle case 2 is fixed to the rear surface of a transmission case 1, and rear axle housings 3 are provided to protrude from both sides of the rear axle case 2.

A rear axle of a rear wheel 4 is supported by a rear axle housing 3.

A PTO shaft 15 is provided protruding from the rear surface of the rear axle case 2, and the PTO shaft 15 is covered with a PTO shaft cover 14.

A hydraulic case 5 is press-fitted on the upper surface of the rear axle case 2, and a lift arm 7 projects rotatably from the hydraulic case 5.

The seat 6 is provided at the top of the hydraulic case 5.

A top link hinge 8 is pivotally installed on the rear surface of the hydraulic case 5.

The lift link 13, which is pivotally supported from the lift arm 13, pivotally connects the middle part of the lower link 10 to its tip, and moves the hydraulic piston provided in the hydraulic case 5 and rotates the lift arm 7 to move the lower link. The link 10 moves up and down.

The essential part of the present invention lies in the method of supporting the lower link hinge pin 23 for pivotally supporting the rotation of the lower link 10.

FIG. 2 is an enlarged side view showing the three-point link type work machine mounting device and the drawbar hitch.

FIG. 3 is a plan view showing the three-point link type work machine mounting device of FIG. 2.

Fig. 4 is a side view with only the drawbar hit part taken out Fig. 5 is a partially sectional side view of the drawbar hitch Fig. 6 is a left side view of Fig. 5 Fig. 7 is a bottom view of Fig. 5 The figure is a right side view of FIG. 5. FIG. 9 is a rear view of the lower link hinge pin. FIG. 10 is a side view of the support.

The drawbar hitch includes a hitch bracket 17, a drawbar hitch 19, a lower link hinge 16, and a hitch pin 2.
0 and tightening bolt 18, drawbar hitch 19
The drawbar 12 is inserted into the hole, and the hole position is selected and fixed using the hit pin 20.

The front and rear ends of the hitch bracket 17 are bent downward to increase the strength in the lateral direction, and the drawbar hitch 19 and the lower link hinge 16 are fixed by welding in the vertical direction to increase the strength.

Further, the bends 17a, 17a have a length that extends beyond the head of the bolt 18, and also serve to protect the head of the fastening bolt 18.

In order to obtain space for tightening the fastening bolts 18, the drawbar hitch 19 was shortened, so in order to reinforce this, the lower link hinge 16 was made into a U shape and fixed to the drawbar hitch bracket 17 by welding, and the drawbar hitch 19 was shortened. It serves both as a left and right steady rest and as a hinge for the lower link hinge pin 23.

Furthermore, it is also used as a fixture for fixing the drawbar hitch pin 20.

Conventionally, the lower link hinge 16 has been fixed and protruded from the side and rear surfaces of the rear axle case, as shown in the side and plan views of the conventional work equipment mounting device shown in FIGS. 11 and 12. However, since there are few installation points,
As the work equipment is repeatedly raised and lowered, the fixed base becomes loose, resulting in a lack of long-term durability.

In order to solve this problem and to support the lower link hinge pin on some surface of the rear axle case 2, it was decided to make the lower link hinge 16 protrude from the drawbar hitch racket 17.

The hole 16b of the lower link hinge 16 is a hole into which the lower link hinge pin 23 is inserted.

Among the holes opened in the drawbar hitch bracket 17, 17c is a hole for inserting a fastening bolt 18, and 17b is a hole for inserting a hitch pin 20. In between hitchi pin 2
0 is inserted and fixed.

Referring to FIG. 3, 11 is a check chain that prevents the lower link 10 from swinging from side to side, and 22 is a bullet that prevents the lower link from rattling and making noise when the working machine is not attached.

The lower link hinge pin supports the inward central part with the lower link hinges 16, 16, and the base 11a of the check chain is fitted on the outside of the lower link hinge pin, which is fixed with a pin 24. A support 21 protruding from the side surface of the rear axle case is attached to the outside of the lower link hinge pin. It is supported at both ends.

The base end of the lower link 10 is fitted into the lower link hinge pin 23 on the outside thereof and fixed with a pin.

As shown in FIGS. 9 and 10, the support 21 is provided with an insertion hole 21a for a bolt fixed to the rear axle case 2 and a hole 21b for the lower link hinge pin 23 to be inserted.

The lower link hinge pin 23 has an insertion opening 23 for a pin 24 for fixing the base 11a of the check chain 11 inside.
A pin hole 23b for preventing the base end of the lower link 10 from being removed is opened on the outside.

FIG. 11 is a side view showing a conventional work machine mounting device, and FIG. 12 is a plan view thereof.

As described above, the present invention fixes the hitch bracket 17 to the lower surface of the rear axle case 2 with bolts, protrudes its rear part further rearward from the rear end surface of the rear axle case 2, and attaches the hitch bracket 17 to the rear axle case. A U-shaped drawbar hitch 19 into which the drawbar 12 can be inserted from the rear is welded and fixed to the lower part, and a U-shaped drawbar hitch 19 is welded to the lower part of the case that protrudes further rearward than the rear end surface of the rear axle case. The lower link hinge 16 is fixed by welding, and an insertion gap for the drawbar 12 is formed in the lower link hinge, the right and left steady rest portions of the drawbar 12, and the drawbar
The lower link hinge pin 23, which is also inserted into the support 21 on the rear axle case side, is inserted into the hole 16b of the part that forms the fixed insertion part of the hitch pin 20 and also projects upward from the hitch bracket 17 to support it. , which has the following effects.

First, the strength of the lower link hinge pin 23 can be reinforced and supported by the lower link hinge 16 on the side where the drawbar hit is attached, and conversely, the strength on the side where the drawbar hit is attached can be reinforced by the lower link hinge pin 23. The work machine mounting device is small in size but strong in that it can support the work equipment by organically relating to each other.

Second, by protruding upward the U-shaped lower link hinge 16 provided on the hitch bracket, the drawbar
12, a left and right steady rest for the toe loader 12, a fixed insertion portion for the drawbar hitch pin 20, and an insertion support portion for the lower link hinge pin 23. .

By using these four functions, the three-point link type work machine mounting device and the drawbar hitch device can be interconnected and reinforced.

[Brief explanation of the drawing]

Figure 1 is a side view of the rear of an agricultural tractor. FIG. 2 is a side view of the work machine mounting device. FIG. 3 is a plan view of FIG. 2. FIG. 4 is a side view with only the drawbar hit section taken out. FIG. 5 is a partially sectional side view of the drawbar hitch. Figure 6 is a left side view of Figure 5. FIG. 7 is a bottom view of FIG. 5. FIG. 8 is a right side view of FIG. 5. FIG. 9 is a rear view of the lower link hinge pin. Figure 10 is a side view of the support. FIG. 11 is a side view of a conventional work machine mounting device. FIG. 12 is a plan view of FIG. 11. 12... Drawbar 16 - Lower link hinge, 17... Drawbar hit bracket, 18... Fastening bolt, 19... Drawbar hit.

Claims (1)

[Scope of utility model registration request] The hitch bracket 17 is fixed to the lower surface of the rear axle case 2 with bolts, and its rear part protrudes further rearward from the rear end surface of the rear axle case 2, and the hitch bracket 17
A U-shaped drawbar hit 19 that allows the drawbar 12 to be inserted from the rear is welded and fixed to the lower part of the rear axle case, and a U-shaped drawbar hitch 19 is welded and fixed to the lower part of the rear axle case. A letter-shaped lower link hinge 16 is welded and fixed, and the lower link hinge forms an insertion gap for the drawbar 12, right and left steady rests for the drawbar 12, and a fixed insertion portion for the drawbar hitch pin 20. This drawbar hit for an agricultural tractor is characterized in that a lower link hinge pin 23, which is also inserted into a support 21 on the rear axle case side, is inserted and supported into a hole 16b in a portion that projects upward.