JPS622669Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a shifter positioning mechanism in a shift device, and aims to eliminate the risk of rust and to simplify the structure to reduce the number of parts and make it more compact.

In a shift device in which a shifter is fitted externally to a transmission shaft mounted in a transmission case so that it cannot rotate relative to it and can freely slide in the axial direction, a lever is attached to the transmission case in order to operate the shifter on the transmission shaft in the axial direction. A shaft is rotatably inserted and supported, a shift fork is fixed to the lever shaft, and the shifter is operated by the shift fork. However, in the above-mentioned shift device, a positioning mechanism is required to hold the shifter at each shift position, and conventionally, the positioning mechanism is provided in an operating system linked to a lever shaft. There were two types: an external type with the mechanism installed inside the shift fork, and an internal type with the mechanism installed inside the shift fork. However, both of the above have the disadvantage of having a large number of parts, and the external type also has the disadvantage of being easily rusted, and the internal type has the disadvantage that it has a large number of parts.
There was also the problem that the shift fork became larger and the entire shift device became larger.

This invention solves the above problems, and
The feature is that a shifter is fitted onto the transmission shaft, and a key provided on the outer circumference of the transmission shaft is engaged with a key groove formed on the inner circumference of the shifter so as to be relatively slidable in the axial direction. Therefore, in a transmission shaft in which a shifter is not relatively rotatable but is slidable in the axial direction, one end of the shifter fitting portion of the transmission shaft is closed by a key, and the other end is closed by a key. An equipment hole is formed in the radial direction that opens on the outer peripheral surface of the equipment hole, and an engagement piece is provided at the other end of the equipment hole so as to be able to move outward in the radial direction. The inner peripheral part of the shifter is provided with a plurality of engagement recesses in which engagement pieces are releasably engaged to position the shifter at each shift position. It is located at the point located at

Hereinafter, one embodiment of the present invention will be explained based on the drawings shown in Figs.
The device is illustrated. In Figures 1 and 2, 1
is the transmission case that makes up the tractor body.
Traveling transmission that transmits power to the rear wheels (not shown)
is built-in, and the rear PTO shaft (not shown)
A PTO transmission shaft 2 that transmits power is mounted on the shaft, and an idling gear 3 that constantly meshes with the transmission gear of the traveling transmission is supported on the PTO transmission shaft 2 via a needle bearing 4 or the like. . Reference numeral 5 denotes a transmission case mounted on the lower side of the transmission case 1 so as to close the opening 6.
A transmission shaft 9 is mounted on the transmission shaft 9 via a pair of front and rear ball bearings 7, 8. The transmission shaft 9 projects forward from the transmission case 5 and is interlocked and connected to the front wheel drive system via a propulsion shaft, etc., and the transmission shaft 9 and the propulsion shaft are connected to the cylindrical cover 1.
covered by 0. The rear end of this cover 10 is removably inserted into a cylindrical part 11 protruding forward of the transmission case 5, and a large diameter part 12 having a larger diameter than other parts is formed at the rear end. There is. A bolt 13 is inserted through the lower end of the cylindrical portion 11 in the width direction, and the contact between the bolt 13 and the large diameter portion 12 prevents the cover 10 from falling off from the cylindrical portion 11. Further, a seal 15 is fitted into the groove portion 14 of the large diameter portion 12. By the way, the transmission shaft 9
A shifter 16 is fitted onto the outside of the shifter 16, and a keyway 17 formed in the front-rear direction on the inner circumference of the shifter 16 is inserted into the transmission shaft 9.
By being engaged with a key 18 fixed to the transmission shaft 9, the shifter 16 is provided so as to be rotatable relative to the transmission shaft 9 and slidable in the axial direction. Note that the shifter 16 may be spline-coupled to the transmission shaft 9.

Thus, the shifter 16 has a gear portion 19 that engages with the idling gear 3, and the gear portion 19 is engaged with and disengaged from the idling gear 3 by sliding the shifter 16 in the axial direction. An equipment hole 20 whose one end is closed by the key 18 is formed through the shifter external fitting portion of the transmission shaft 9 in the radial direction. The illustrated engagement piece 21 is provided so as to be able to move outward in the radial direction. In addition, in the equipment hole 20, an elastic spring 22, which is illustrated as a coil spring, is inserted between the key 18 and the engagement piece 21, so that the engagement piece 21 is attached to the outside in the radial direction. It is pressed against the inner circumferential portion of the shifter 16. Furthermore, a pair of front and rear engagement recesses 23 and 24, exemplified by circumferential grooves, are arranged in parallel in the axial direction on the inner circumference of the shifter 16, and the engagement piece 21 can be freely engaged and detached from these engagement recesses 23 and 24. By being engaged, shifter 1
6 is positioned and held at each shift position of connection and disconnection. 2
A lever shaft 5 is rotatably inserted and supported in the transmission case 5, and a lever 26 is fixed to the outer end of the lever shaft 25, and a shift fork 27 is fixed to the inner end of the lever shaft 25.
28 is a seal. The lever 26 is connected via a rod 29 to an operating lever near the driver's seat. The shift fork 27 has a flat plate shape, and a pin 31 that engages with the circumferential groove 30 of the shifter 16 is inserted and fixed at the upper end.

In the above configuration, when the lever 26 is pushed down via the rod 29, the shift fork 27 rotates counterclockwise around the lever shaft 25, and the shifter 16 slides forward, as shown by the solid line in FIG. When the shift position is reached, the gear portion 19 of the shifter 16 meshes with the idle gear 3. Therefore, idle gear 3, shifter 1
6. Via the key 18, power can be transmitted from the engine to the transmission shaft 9, and the front wheels can be driven. At this time,
The engagement piece 21 engages with the rear engagement recess 24 to position and hold the shifter 16 at the contact shift position. Next, if you pull up the rod 29, lever 2
6. The shift fork 27 rotates clockwise around the lever shaft 25, and the shifter 16 slides rearward to reach the disengaged shift position shown by the imaginary line in FIG.
Since the gear portion 19 of the shifter 16 and the idle gear 3 are disengaged, power transmission to the front wheels is interrupted. At this time, in response to the sliding of the shifter 16, the engaging piece 21 disengages from the rear engaging recess 24 while compressing the bullet 22, relatively slides on the inner circumferential surface of the shifter 16, and engages the front engaging piece 21. The shifter 16 is engaged with the mating recess 23, whereby the shifter 16 is positioned and held at the disengaged shift position. By the way, in the above case, the engagement piece 21 biased by the bullet 22 is provided in the installation hole 20 of the transmission shaft 9, and the engagement piece 21
Since the positioning mechanism is built into the transmission shaft 9 and the shifter 16 so that it can be freely engaged and disengaged from the engagement recesses 23 and 24 on the inner circumference of the shifter 16, there is no risk that the positioning mechanism will rust, and the entire device will be protected. Can be made compact. Further, the only members added as a positioning mechanism are the engagement piece 21 and the bullet 22,
Since the other parts can be processed by simple machining of the transmission shaft 9 and shifter 16, the structure is simpler than before, and the number of parts can be reduced.

As shown in FIG. 3, if both radial ends of the equipment hole 20 formed through the transmission shaft 9 in the radial direction and the key 18 are shifted in the circumferential direction, the ammunition 22 installed in the equipment hole 20 can be It is also possible to use a material with a longer natural length than the above embodiment.

In addition, in the embodiment, a ball was used as the engagement piece and the circumferential groove was used as the engagement recess, but the engagement piece does not have to be spherical, and the engagement recess may have a shape other than the circumferential groove. Good too.

As described in detail above, the present invention includes an engagement piece biased by a bullet in the installation hole of the transmission shaft, and the engagement piece is freely engaged and detached from the engagement recess on the inner circumference of the shifter. Since the positioning mechanism is constructed internally in the transmission shaft and shifter, there is no risk that the positioning mechanism will rust, and the structure is simple, with a small number of parts, and can be made compact.

Also, one end of the equipment hole is closed with a key, and the ammunition in the equipment hole is inserted between the key and the engagement piece in a spring-like manner, so that the end of the equipment hole opposite to the engagement piece is closed. , the bullet can be received in a reliable and stable state, there is no risk that the opposite end of the bullet will be twisted, and a separate member is provided to receive the opposite end of the bullet. There's no need to do that.
Furthermore, the force of the bullet prevents the keys from rattling.

[Brief explanation of the drawing]

Fig. 1 is a sectional view showing one embodiment of the present invention;
The figure is a sectional view taken along the line AA in FIG. 1, and FIG. 3 is a sectional view showing a comparative example of the present invention. 1...Mission case, 5...Transmission case,
9...Transmission shaft, 16...Shifter, 18...Key,
20...equipment hole, 21...engaging piece, 22...munition machine, 23, 24...engaging recess.

Claims (1)

[Claim for Utility Model Registration] A shifter is fitted onto the transmission shaft, and a key provided on the outer periphery of the transmission shaft is engaged with a key groove formed on the inner periphery of the shifter so as to be relatively slidable in the axial direction. By doing so, in a device in which the shifter is provided on the transmission shaft so as to be non-rotatable relative to each other and slidable in the axial direction, one end of the shifter fitting portion of the transmission shaft is closed with a key, and the other end is closed with a key. An equipment hole that opens on the outer circumferential surface of the shaft is formed in the radial direction, an engagement piece is provided at the other end of the equipment hole so as to be able to move outward in the radial direction, and a key and the engagement piece are provided in the equipment hole. A plurality of engagement recesses are provided in the inner circumference of the shifter, and engagement pieces are releasably engaged to position the shifter at each shift position. A shifter positioning mechanism in a shift device, characterized in that the shifter is arranged in the direction of the shifter.