JPS6041262B2 - Gear return device for multi-gear transmission to neutral position - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a return device for returning a sliding gear of a multi-gear transmission in a motorcycle or the like from an engaged state to a neutral position.

For motorcycles, for example, Utility Model Publication No. 47-2484
As seen in Publication No. 4, a cam cylinder that rotates by a predetermined angle in conjunction with the operation of a foot-operated gear change lever is provided, and a plurality of cam grooves extending in the circumferential direction are provided on the outer periphery of this cam joint. A fork shaft is provided which is arranged parallel to the cam cylinder, the intermediate part is slidably held on the fork shaft, the base end is aligned with the cam groove of the cam cylinder, and the distal fork part is connected to the fork shaft. A gear transmission is usually provided with a shift fork that rotatably connects a sliding gear that is slidably held on a parallel input shaft or output shaft. In such a gear transmission, the gear change lever can only perform gear change operations in stages, so in order to return the sliding gear to the neutral position from a gear change position that is not directly adjacent to the neutral position, it is necessary to There was a problem in that it was necessary to operate the change lever several times to return it one step at a time, and the operation was not easy.

The present invention provides a device for returning a gear shift gear to a neutral position in a gear transmission that solves such problems, and is capable of returning the gear gear to the neutral position at once even from a false gear shift position that is not adjacent to the neutral position. It is characterized by being able to do the following.

Embodiments of the present invention will be described below with reference to the drawings. 1st
In the figure, 1 is a gear case of a motorcycle, 2 is a cam cylinder that is rotatably held in the gear case 1, and is arranged parallel to the fork shafts 3, 3' inside the gear case 1. The cam cylinder 2 is rotated by the gear case. It is provided in parallel with the input and output ports 4, 4' (FIGS. 2 and 3) of the transmission, which are freely held.

The fork shaft 3 is provided with small-diameter shaft portions 3a, 3c provided at both ends, and is located between and integral with the ball portions 3a, 3c, and is provided integrally with the ball portions 3a, 3c. It has an eccentric spinal cord part 3b whose axis is eccentric. Like the fork shaft 3, the fork shaft 3' also has small diameter shaft portions 3'a, 3'c and an eccentric spinal portion 3'b. These respective shaft portions 3a, 3c and 3'a, 3'c have their tracking lines aligned with each other, and are rotatably held in the gear case 1. The outer periphery of the cam cylinder 2 has cam grooves 5, 6, which extend in the circumferential direction.
7 are arranged in parallel at a predetermined interval in the axial direction of the cam cylinder 2.

In FIGS. 4 and 5, each of the cam grooves 5, 6, and 7 includes neutral position cam grooves 5a, 6a, and 7a, meshing position cam grooves 5b, 6b, and 7b, respectively. 5c denotes neutral position cam grooves 5a, 5a before and after the meshing position cam groove 5b, and meshing position cam groove 5b.
6c is a stepped portion that linearly connects the front and rear neutral position cam grooves 5a, 5a, and a green portion 6c faces the meshing position cam groove 6b and the front and rear neutral position cam grooves 6a, 6a. , a stepped portion 7c that linearly connects the front and rear neutral position cam grooves 6a, 6a, and 7c is a step portion facing the meshing position cam groove 7b and the front and rear neutral position counterfeiting cam grooves 7a, 7a; This is a step that linearly connects the cam grooves 7a, 7a, and is formed within the cam grooves 5, 6, and 7.

8, 9, and 1 rivers in Figure 1 are shift forks.

Each of the shift forks 8, 9, and 1 has boss portions 8a, 9a, and 10a at the base end, and mating protrusions 8b, 9b, and 10b that are integrated with each of the boss portions 8a, ga, and 10a, and the tips thereof. Fork parts 8c, 9c (shift fork 10
(the fork portions are not shown). The engaging protrusions 8a, 9a, 10a are aligned with the cam grooves 5, 6, 7, respectively, and the boss portions 8b, 1ob are freely engaged with the eccentric spinal portion 3b of the forkshaft 3, and the boss portion 9b is slidably fitted to the eccentric pith portion 3'b of the fork shaft 3'.

The fork parts 8c, 9c can rotate relative to the sliding gears 11, 12, and lock the super dynamic gears 11, 12 to the fork parts in the longitudinal direction of the input/output shafts 4, 4'. The grooves 11a in the circumferential direction of the sliding gears 11 and 12,
12a (FIGS. 2 and 3). In FIGS. 1 and 6, the forkshaft 3 has a first arm 13.
The intermediate portion of the second arm 14 is fixed, and the base end portion of the second arm 14 is fixed to the fork shaft 3'.

One end of an intermediate link 15 is pivotally attached to the base portion of the first arm 13, and the intermediate link 15 is pivotally attached to the tip of the second arm 14.
The other end is pivotally connected. A spring 16 is attached to one end of the first arm 13 and the gear case 1.

This spring 16 urges the first arm 13 clockwise in FIG. In Fig. 6, 17 is a shaft rotatably held in the gear case 1 parallel to the cam cylinder 2;
An intermediate portion of the third arm 18 is integrally fixed to the.

One side 18a of the tip of the third arm 18 is connected to the first arm 1.
It is pressed against the tip of 3. An arcuate cam surface 18b centered on the axis of the shaft 17 is formed on the other side of the tip end of the third arm 18. A spring 19 is attached to the base end of the third arm 18 and the gear case 1, and urges the second arm 18 counterclockwise in the figure. One end of a cable 20 is pivotally connected to the base end of the third arm 18. The end of the cable 20 is connected to an operating lever (not shown) near the handlebar of a two-wheeled motor vehicle, for example. Note that 21 is a stopper, and 22 is an outer wire. The cam cylinder 2 has a locking protrusion 23 protruding from the outer periphery of the side ends 2a of the arms 13 and 14, and a locking claw 24 that abuts the locking protrusion 23 is provided at the base end of the first arm 13. It is provided.

25 is a cam barrel 2 that protrudes laterally from the end 2a of the cam barrel 2;
A gear 26 is iron-coupled to the shaft portion 25 .

A plurality of rectangular spaces 27 that contract clockwise are formed at predetermined intervals in the circumferential direction between the gear 26 and the shaft portion 25, and a ball 28 is inserted into the sliding space 27. has been done. A base end portion of a sector gear 29 that meshes with the gear 26 and rotates the gear 26 is rotatably supported on the shaft 17. This sector gear 29 has one end connected to the third arm 18.
It is biased clockwise by a spring 31 that is engaged with a pin 30. Reference numeral 32 designates a sector gas stopper protruding from the base end of the third arm 18.

When the locking projection 23 mentioned above touches the locking pawl 24 at the position indicated by the broken line, the locking projection 8b of the shift fork 8, 9, 10
, 9b, 10b are provided so as to be located within the neutral position cam grooves 5a, 6a, 7a. Figure 2, 33 in Figure 3
34 is a circle indicating the position of the step portions 5c, 6c, and 7c of the cam barrel 2; 35 is the cam barrel 2;
This is a circle indicating the position of the bottom surface of the cam grooves 5, 6, and 7. Next, other configurations of such a gear return mechanism will be explained along with its operation.

When the cable 20 is pulled to the left in Fig. 6, the third arm 18
is rotated clockwise around the shaft 17, the first arm 13 is rotated counterclockwise in the figure around the fork shaft 3, and the fork shaft 3 is rotated counterclockwise. , the second arm 4 is interlocked with the first arm 13 via the intermediate link 15, and rotates clockwise in the figure around the fork shaft 3'.
is laid clockwise in the figure.

As a result, the rotary shaft portions 3b, 3'b are centered around the axis 0 of the shaft portions 3a, 3c and 3'a, 3'c and the cam cylinder 2 in
It is displaced in the direction of arrow A away from a circle 33 indicating the outer circumferential surface of (see the dashed-dotted line in FIGS. 2 and 3).

Furthermore, when the cable 20 is displaced to the left in FIG. 6 and the tip of the first arm 13 is displaced onto the cam surface 18a of the third arm 18, the engaging protrusion 8b of the shift fork 8, 9, 10 , 9b, 10b are displaced to the outside of the circle 34 as shown in FIG. 3, and the stepped portions 6c, 7 as shown in FIG.
Displaced slightly above c.

When the cable 20 is further displaced to the left in FIG. 6 from this state, the sector gear 29 meshes with the gear 26, and the gear 26 rotates counterclockwise in FIG.

As a result, the ball 28 is brought into pressure contact with the gear 26 and the ball portion 25, and the wisteria portion 25 is rotated counterclockwise in the figure. As a result, the cam section 2 rotates together with the bag portion 25. When the cam cylinder 2 is rotated in this manner, as shown in FIG. 3 or FIG. Parts 5c, 6c,
Since it is located above 7c, for example, cam cylinder 2
is rotated in the direction B in FIG. 5, each engaging protrusion 8b, 9b, 10b can be returned to the neutral position N in a straight line without being affected by the shape of the cam groove. That is, the engagement protrusion 8
b passes over the stepped portion 5c, and the engaging protrusion 9b passes over the stepped portion 6c and returns linearly to the neutral position. Furthermore, the engagement protrusion 10 on the right end
b is forcibly returned to the straight line by the cam shape of the cam groove 7b for the engaged position, but in this state there is no problem as the gear moves in the direction of disengaging the gear, and continues to pass over the step 7c and return to the neutral position. Return to Fake N. Thereafter, the rotation of the cam cylinder 2 is stopped when the locking protrusion 23 of the cam shaft 2 comes into contact with the locking pawl 24 of the first arm 18. At this time, the spring 31
, and the impact force at this time is absorbed. By such an operation, the sliding transmission gears 11, 12, etc. are disengaged from the transmission gear (not shown).

Next, when the cable 20 is returned to its original position, the first arm 13, second arm 14, third arm 18, etc. are connected to the springs 16, 1
It is returned to its original state by the spring force of 9. At this time, the sector gear 29 rotates the gear 26 clockwise in FIG. 6, but the ball 28 disengages the gear 26 from the ball 25, so the cam cylinder 2 rotates clockwise in the diagram. is not rotated, and only the gear 26 is rotated clockwise. As a result, the neutral position of the shift forks 8, 9, 10, the conventional cam grooves 5a, 6a.
, 7a to the lower surface side, and is prepared for the next shift operation.
In the embodiment described above, the cam cylinder 2 is rotated by the gear 26 and the sector gear 29 to return the shift forks 8, 9, and 10 to the neutral position, but the invention is not necessarily limited to this. , when the cable 20 shown in FIG. 7 is displaced to the left in the figure, the elastic force of the compression spring 38 moves the stopper roller 37, which is in pressure contact with the pins 36, 36 (FIG. 8) at one end of the cam cylinder 2. pin 3 against
6 and 36, and by biasing the cam cylinder 2 in FIG.
The cam link 2 may be configured to rotate counterclockwise in FIG. 7 when it is separated from 36.

In FIG. 7, one end of the spiral spring 39 is fixed to the shaft portion 25 of the cam cylinder 2, and the other end is fixed to the gear case 1 side, and in FIG.
It is pivotally connected to an arm 41 which is pivotally connected via 0.

As explained above, the present invention displaces the engaging protrusion of the shift fork by pulling the cable to the space side above the stepped part that fits in a straight line with the cam groove for direct use in the neutral position, and then rotates the cam barrel. Since the engagement protrusion of the lever is provided to return to the neutral position (the position before the first gear shift position), it is necessary to operate the change lever several times to return the sliding shift gear to the neutral position, as with the follower. Even in such a case, the sliding gear can be returned to the neutral position with one operation.

[Brief explanation of the drawing]

Figure 1 is a sectional view showing one embodiment of the present invention, Figures 2 and 3 are
The figure is a side view showing the relationship between the shift fork and the cam barrel, Figure 4 is a sectional view taken along line W-W in Figure 5, Figure 5 is a developed view of the cam barrel, and Figure 6 is the left side of Figure 1. 7 is a side view of a cam section showing another embodiment of the present invention, FIG. 8 is a side view of the pin side of the cam comb, and FIG. 9 is an engagement protrusion when returning to the neutral position N'. 6 is a sectional view taken along the line N-W in FIG. 5. FIG. 1... Gear case, 2... Cam cylinder, 3, 3'... Fork shaft, 3b, 3'b... Eccentric shaft portion, 5, 6, 7...
...Cam groove, 5a, 6a, 7a... Neutral position counterfeit cam register part, 5b, 6b, 7b... Cam groove part for meshing position,
5c, 6c, 7c...Step part, 8, 9, 10...Shift fork, 8b, 9b, 10b...Engaging protrusion, 11,
12...Sliding transmission gear. Figure 1 Figure 4 Figure 2 Figure 3 Figure 5 Figure 6 Figure 7 Figure 8 Figure 9

Claims (1)

[Claims] 1. A cam cylinder rotatably held in a gear case, a cam groove formed in the circumferential direction on the outer circumferential surface of the cam cylinder, and an engagement provided by bending the middle of the cam groove to the side. communicates with the position cam groove and the meshing position cam groove,
and a step formed on the cam cylinder so as to linearly connect the front and rear neutral position cam grooves, and a fork shaft disposed parallel to the cam cylinder and rotatably held in the gear case. an eccentric shaft portion provided at an intermediate portion of the fork shaft; a shift fork having one end rotatably held by the eccentric shaft portion and the other end engaging the sliding gear; and the cam groove. and an operating means for rotating the cam cylinder and the fork shaft, and when the fork shaft is rotated by the operating means for rotating the fork shaft, the fork is rotated. A shift fork whose one end is rotatably supported by the eccentric shaft of the shaft is displaced, and the engagement protrusion of the shift fork moves from the meshing position cam groove to the upper part of the stepped part, and in this state, the cam cylinder is moved. A shift gear return device for a multi-stage gear transmission to a neutral position, characterized in that, when rotated, an engaging protrusion of the shift fork fits into a neutral position cam groove from above the step.