JPS6018005Y2 - Agricultural tractor lower link shaft attachment device - Google Patents

Description

[Detailed Description of the Invention] [Industrial Field of Application] The present invention aims to improve the strength of a lower link shaft in a three-point link mechanism installed at the rear of an agricultural tractor.

[Conventional technology and its problems]

Conventionally, this type of lower link shaft has been disclosed in, for example, Japanese Utility Model Application No. 54-125308 and Japanese Utility Model Application No. 54-135307.
As seen in the publication, a pipe is inserted into the lower link shaft, or a lower link flange, a support or bracket, a lower link flange, and a check change hinge are attached to the shaft itself, and these are designed to withstand the harsh conditions of agricultural tractors. A force acts.

Therefore, there is a problem with its durability, and to avoid this,
As seen in the above publications, various proposals have been made.

By the way, bending stress acts on such shafts and pipes, inducing deformation, but the proposal of the above-mentioned publication is not sufficient to prevent such deformation.

That is, the first point of dissatisfaction is that
In Publication No. 25308, although a shaft and a pipe are used, the lower link hinge is supported by the shaft and is not reinforced by the pipe.Secondly, the pressure receiving area of the lower link hinge is small and concentrated. Easy to induce stress.

The third point is that this kind of pipes and shafts that are supported at both ends are most deformed in the center, but in order to prevent this deformation, brackets are welded to the outer periphery of the pipe to support it, so there is a risk of damage to the pipe. is likely to occur.

[Means for solving problems]

Therefore, the present invention solves these unsatisfactory points.

Hereinafter, the structure of the present invention will be explained in detail with reference to embodiments shown in the accompanying drawings.

Fig. 1 is a schematic diagram of an agricultural tractor to which the present invention is applied, in which 1 is a front tire, 2 is a rear tire, 3 is an engine, 4 is a clutch housing, 5 is a transmission case, 6 is a handle, and 7 is a bonnet. , 8 is a seat, 9 is a hydraulic cylinder case, 10 is a lift arm, 11 is a PTO shaft, 12 is a three-point link lower link, 13 is a three-point link lift link, 14 is a lower link shaft, 15 is a lower link hinge , 16 is a plate support.

FIG. 2 is an enlarged view of the main part, and a butterfly-shaped support 16 is bolted to the mission case rear lid 17 surface of the mission case 5.

The butterfly-shaped support 16 is welded to and protrudes from the outer periphery of a pipe 18 fitted into the lower link shaft 14.

As shown in FIGS. 3 and 4, this pipe 18 is provided with a lower link hinge 15. One end of the lower link hinge 15 is fitted into and welded to the pipe 18, and the other end is attached to the transmission. Bolt 2 below the side of case 5
It is stopped at 2.

Further, a boss pipe 19 is loosely fitted into this pipe 1B with the support 16 in between.
A check chain hinge 20, which is fitted and welded to the check chain, protrudes and is linked to a check chain (not shown).

A lower link flange 21 is welded to the lower part of the outer circumference of the pipe 18, and a drawbar hitch bracket 24 is attached to the bolt hole 23 of this flange 21 with bolts.

As shown in the parts diagram of FIG. 5, the drawbar hitch bracket 24 is removably fixed to the lower surface of the transmission case 5 with bolts 25.

A three-point link lower link 12 is loosely fitted on both sides of the lower link shaft 14, and the lower link 12 is fixed with a pin 28 at the tip of the shaft.

Therefore, the power from the engine 3 is transmitted via the PTO shaft 11 to a working machine (for example, a rotary tiller), which is a three-point link lower link 12 -> lower shaft 14 -> pipe 18 -> lower hinge 15 -> transmission case. The lower link 12 is pulled up together with the check chain in the order of 5, and when lifting the work equipment, the lower link 12 is raised by the lift link 13 around the lower link shaft 14.

Therefore, severe loads from the working machine act on the lower link shaft 14 and the pipe 18.

Since the lower link hinge 15, check chain hinge 20, and support 16 are integrated into the pipe 18 into which the lower link shaft 14 is loosely fitted, these structures can be easily replaced.

In summary, since the present invention is constituted by the description of the claims for utility model registration, it achieves the effects listed below.

[Effect of idea]

■ Since the pipe 18 is supported at both ends of the pipe 18 into which the check chain hinge 20.20 is loosely fitted, and also supported by the plate support 16 in the center, the pipe 18 is prevented from deforming due to the tal of the shaft 14. is,
It can withstand the harsh forces of agricultural tractors.

In addition, the plate support 16 is welded to the upper part of the center of the pipe 18, and the lower link flange 21 is welded to the lower part of the pipe 18, and the pipe 18 is equally sandwiched from above and below, so that the pipe 18 is reinforced in a distributed manner. , to better prevent its deformation.

As a result, the shaft 14 does not become flat, and removal of the shaft 14 is not hindered.

(2) Since the check chain hinge 20 is fitted into the pipe 18, which naturally has a larger diameter than the shaft 14, the pressure receiving area of the hinge 20 is expanded and stress concentration is eliminated.

■ The pipe 18 is provided with a plurality of lower link hinges 15, the plate support 16 is provided with a check change hinge 20, and a plurality of lower link flanges 21, so that they can be easily attached to the transmission case 5. I can,
Inspection and replacement are also easy.

■ The center of rotation of the lower link 12 and the center of rotation of the check chain hinge 20 are on the same line, and deformation of the shaft 14 and pipe 18 is suppressed as much as possible.
There is no rotational error and no imbalance occurs in its performance.

Note that the lower link flange 21 is fixed to the pipe 18,
When the drawbar hitch bracket 24 is attached to the lower link flange 21, the three-point link is firmly attached to the transmission case in conjunction with the hinge 15 and support 16 of the lower link.

[Brief explanation of drawings]

Figure 1 is an external view of the tractor, Figure 2 is a side view of the main parts, Figure 3 is a front view of the lower link shaft mounting device, and Figure 4 is the third
Figure 5 shows a side view of the Drover Hitch. 5...Mission case, 12...Lower link, 14...Lower link shaft, 15
...Lower link hinge, 16...Plate support, 18...Pipe, 20...
Check change hinge.

Claims (1)

[Scope of utility model registration request] The lower link shaft of an agricultural tractor has one long pipe 18 that spans the bases of both lower links 12 and has a portion extending in the left-right direction, and a lower link shaft 14 is removably fitted into the pipe 18. At both ends of the pipe 18, lower link hinges 15, 15 are attached to both sides of the mission case 5, and at the upper center, a plate support 16 is attached to the rear cover 17 of the mission case that supports the PTO shaft 11. At the lower center, lower link flanges 21 having a width approximately the same as the width in the lateral direction of the plate support 16 are welded and protruded from the outer periphery of the vibrator 18, and are adjacent to each other on both sides of the support 16. A lower link shaft mounting device for an agricultural tractor, characterized in that a check change hinge 20.20 is rotatably fitted to the outer periphery of the pipe 18 inside the lower link hinges 15, 15.