JPH0249150Y2 - - Google Patents

Description

[Detailed Description of the Invention] <Industrial Application Field> The present invention relates to a gear shift operation device for a tractor equipped with a PTO transmission, a forward/reverse switching device, and the like.

<Prior art> In general, tractor transmissions include main transmission, auxiliary transmission, PTO transmission, super reduction (creep transmission), front wheel drive switching, and forward/reverse switching (shuttle).
There are cases where a super speed reduction device and a forward/reverse switching device are installed together, and cases where only one is installed.

Although there are differences in the presence or absence of a back gear and the gear ratio between a super-reduction device and a forward/reverse switching device, they transmit driving system power, have similar gear arrangement structures, and can be placed in the same position. Therefore, if only one of the two devices is installed, it is possible to use the operating system from the shift fork to the operating lever.

Various control levers are designed to facilitate operation.
They are often placed on the side of the seat, and the control levers placed on the same side also share a pivot point, and the control lever for the super-reduction device or forward/reverse switching device also shares the pivot point with the PTO control lever. ing.

<Problems to be solved by the invention> The forward/reverse switching device increases the backward movement function of the tractor by setting the reverse speed to approximately the same number of gears as the forward speed, and is superior to ultra-reduction devices, PTO transmissions, etc. The frequency of operation is extremely high. Therefore,
If a forward/reverse switching device is installed instead of a super reduction gear, if the control lever is pivoted to the same axis as the PTO control lever, the control lever will be located below the side of the seat, making it possible to operate it but difficult to operate. It is also conceivable to bend and lengthen the operating lever so as to extend it to a position where it can be easily operated, but this may cause interference with other operating levers and also pose problems in lever strength.

<Means for solving the problem> In the present invention, a pivot 29 is arranged above the horizontal shaft 17 that pivotally supports the PTO operating lever 19, and a forward/reverse switching operating lever 38 is attached to the outer end of this pivot 29. By attaching interlocking members 30, 40, etc. for rotating the shift fork shaft 13 for the forward/reverse switching device using the pivot shaft 29 and the horizontal shaft 17, all of the problems of the prior art can be solved. This is something that can be solved.

That is, the feature of the specific configuration of the problem-solving means in the present invention is that a support stand 16 is fixed to the side of the transmission case 2 below the side of the seat 8, and the PTO operating lever 19 is fixed to the support stand 16. In a tractor speed change operation device provided with a supporting horizontal shaft 17, a swinging arm 40 for rotating a shift fork shaft 13 for a forward/reverse switching device is provided on the horizontal shaft 17, and a bracket 34 is fixed to the support base 16. A pivot shaft 29 is rotatably disposed above and parallel to the horizontal shaft 17 on this bracket 34, and an arm 30 is fixed to the inner end of this pivot shaft 29, so that the swing arm 40
and a rod 31 whose length can be adjusted freely, and a forward/reverse switching operating lever 38 is provided at the outer end of the pivot shaft 29.

<Function> Horizontal shaft 17 that pivots the PTO operating lever 19
Since the pivot 29 is arranged above and the forward/reverse switching operating lever 38 is provided on this pivot 29, the pivot point of the operating lever 38 is at a higher position than when it is attached to the horizontal shaft 17, and the shift fork is placed inside the pivot 29. Since the arm 30 that interlocks with the seat 10 is attached and the operating lever 38 is attached to the outer end, the operating lever 38 projects outwardly with respect to the seat 8 without interfering with other operating levers 19 and the like.

<Example> Hereinafter, an example of the present invention will be described based on the drawings.

In FIGS. 1 and 2, 1 is the body of an agricultural tractor formed by directly connecting an engine, a clutch housing, and a transmission case 2. Only the rear upper part of the transmission case 2 is shown. A PTO transmission case 3 is attached to the back, a hydraulic system 4 for raising and lowering the work machine is mounted on the upper part, and a brake case 5 is attached to the left and right sides of the PTO transmission case 3. From this brake case 5, left and right rear axle boxes 6 are installed. Projected outward.

A floor sheet 7 covers the rear upper part of the vehicle body 1. A seat 8 is provided at the center of the upper surface of the floor sheet 7, and its left and right ends are connected to fenders 9 for rear wheels.

Although not shown in the transmission case 2, a main transmission, an auxiliary transmission, a front wheel drive switching device, a forward/reverse switching device, etc. for the driving system are built in, and the shift fork 10 of the forward/reverse switching device is connected to the shift shaft. 11
The shift fork shaft 13, which has the lever 12 fixed to its inner end, passes through the transmission case 2, and an arm 14 is fixed to its outer end. There is.

16 is a support fixed to the side of the hydraulic device 4 (or the side of the transmission case 2);
It is located below the side when viewed from the seat 8, and rotatably supports both ends of the horizontal shaft 17.

A boss 18a of an arm 18 for PTO operation is fitted in the middle of the horizontal shaft 17.
The PTO operating lever 19 is fixed, and the arm 18 is connected to a fixed arm 21 via a connecting rod 22 to a shift fork shaft 20 that penetrates the PTO transmission case 3. By rotating, arm 1
8, the transmission inside the PTO transmission case 3 can be operated (on/off operation).

The PTO transmission may be installed inside the transmission case 2, in which case the connecting rod 22
The position of the horizontal shaft 17 and the PTO operating lever 19 remains unchanged.

At the outer end of the horizontal shaft 17 protruding from the support base 16 is an operating lever 23 for operating the front wheel drive device.
is fixed, and an arm 24 is fixed to the middle of the horizontal shaft 17, and the rotational force of the operating lever 23 is used to operate the front wheel drive switching device disposed inside or at the bottom of the transmission case 2 via the horizontal shaft 17 and the arm 24. It's becoming possible.

An arm 26 is loosely fitted to the inner end of the horizontal shaft 17, and the arm 26 is connected to the arm 26 via a rod 27 whose length is freely adjustable.
6 is interlocked and connected to the arm 14. The rod 27 and both arms 14, 26 are connected via a ball joint. Arm 26 boss 2
An arm 28 is welded to 6a, and both arms 26 and 28 form a bell crank-shaped swinging arm 4.
It is 0.

Reference numeral 29 denotes a pivot located directly above and parallel to the horizontal shaft 17, and an arm 30 is fixed to the inner end of the pivot shaft.This arm 30 and the arm 28 on the horizontal shaft 17 are connected to a rod 31 whose length can be freely adjusted. This rod 31 and each arm 28, 30 are connected via ball joints 32, 33.

Reference numeral 34 denotes a bracket fixed to the support base 16 via bolts 35, the lower part of which is fixed to the vehicle body 1 by also using the bolts 36 that attach the rear axle box 6 to the brake case 5; A cylindrical body 37 is fixed to the upper part of 34, and this cylindrical body 37
supports the pivot shaft 29 rotatably.

A forward/reverse switching operation lever 38 is provided at the outer end of the pivot 29.
is fixed, and the rotation of the operating lever 38 is transmitted to the arm 30 via the pivot 29, and from the arm 30 to the arm 28, the boss 26a, and the arm 26.
is transmitted to the rod 27 via the arm 14.
Shift fork shaft 1 for forward/reverse switching device via
3 to switch the driving system power inside the transmission case 2 between forward and reverse directions.

39 is a hand clutch lever provided on the floor seat 7, which is located near the seat 8;
The forward/reverse switching operation lever 38 is located outward from the hand clutch lever 39.

If the transmission case 2 has a built-in super deceleration device instead of the forward/reverse switching device, the shift fork 10, shift shaft 11, lever 12, shift fork shaft 13, arm 14, and rod 27
is used as is, the position of the shift fork shaft 13 is kept the same, and the swing arm 40, rod 31, arm 30 and operating lever 38 are removed.
A super deceleration operating lever attached to the boss 26a of an arm 26 is loosely fitted onto the horizontal shaft 17.

<Effects of the invention> According to the invention described in detail above, the swinging arm 40 that rotates the shift fork shaft 13 for forward/reverse switching is loosely fitted to the horizontal shaft 17 that supports the PTO operation lever 19, and the Pivot 29 above and parallel to axis 17
is arranged rotatably, an arm 30 that is interlocked with the swing arm 40 is fixed to the inner end of this pivot shaft 29, and a forward/reverse switching operation lever 38 is provided at the outer end, so that the forward/reverse rotation can be performed. Compared to the case where the switching operation lever 38 is provided on the horizontal shaft 17, the pivot point can be placed at a height closer to the seat 8 and on the outside, making it easier to operate the operating lever that is frequently used. Can be done. In addition, since the swinging arm 40 and the arm 30 are connected by a rod 31 whose length is freely adjustable, the forward/reverse switching device can be operated accurately.
4 is attached to the support stand 16, the bracket 3 is attached at a position outwardly away from the mission case 2.
4 can be arranged, thereby making it possible to firmly support the pivot shaft 29.

[Brief explanation of the drawing]

The drawings show an embodiment of the present invention, and FIG. 1 is a partially sectional side view, and FIG. 2 is a sectional front explanatory view. 2...Mission case, 8...Seat, 10...
...Shift fork, 13...Shift fork axis,
16...Support stand, 17...Horizontal axis, 19...PTO
Operation lever, 29... Pivot, 30... Arm, 3
4... Bracket, 38... Forward/reverse switching operation lever, 40... Swing arm.

Claims (1)

[Claims for Utility Model Registration] A tractor gear shift operation in which a support stand 16 is fixed to the side of the transmission case 2 below the side of the seat 8, and a horizontal shaft 17 for supporting a PTO operating lever 19 is provided on the support stand 16. In the device, a swing arm 40 for rotating the shift fork shaft 13 for the forward/reverse switching device is provided on the horizontal shaft 17, a bracket 34 is fixed to the support base 16, and a swing arm 40 is provided on the horizontal shaft 17 above the horizontal shaft 17. In addition, a pivot shaft 29 is rotatably disposed in parallel thereto, and an arm 30 is fixed to the inner end of this pivot shaft 29 to rotate the swing arm 40.
A tractor speed change operating device characterized in that a forward/reverse switching operating lever 38 is provided at the outer end of the pivot shaft 29, and the pivot shaft 29 is connected by a length-adjustable rod 31.