JP6783167B2 - Transmission change mechanism - Google Patents

Description

The present invention relates to a change mechanism that rotates a change drum that operates a shift fork of a transmission of a vehicle such as a motorcycle.

Generally, in a motorcycle transmission, the change lever rotates in conjunction with the operation of the rider's change pedal. When the change lever rotates, the shift claw provided on the change lever presses a passive protrusion called a pin provided on the change cam, and the change cam and the change drum rotate at regular intervals (angles). When the change drum rotates, the shift fork guided by the spiral cam groove slides in the vehicle width direction to shift the transmission (shift change) (for example, Patent Document 1).

Japanese Unexamined Patent Publication No. 2002-120585

In a transmission as in Patent Document 1, the shift claw of the change lever presses the passive protrusion of the change cam, so that the change cam rotates. That is, at the time of pressing, the shift change is performed by generating a rotational force larger than the rotation resistance of the change lever (the resistance received from the contact surface between the shift claw and the passive protrusion). When such a rotation resistance is small, the feeling of moderation when the rider operates the change pedal is also small.

An object of the present invention is to provide a change mechanism for a transmission that can increase the moderation of a change pedal and improve the accuracy of shift operation.

In order to achieve the above object, the change mechanism of the transmission of the present invention is a change mechanism that rotates a change drum that operates a shift fork of the transmission, and is a change cam that rotates integrally with the change drum and a change pedal. A change lever that rotates in conjunction with the operation of the change cam to intermittently rotate the change cam is provided, and a shift claw provided on the change lever presses a passive protrusion provided on the change cam. Rotation of the change cam occurs, and the resistance to a part of at least one of the contact surfaces of the shift claw and the passive protrusion increases the rotation resistance of the change lever at the time of pressing more than the other parts of the contact surface. The part is formed.

According to this configuration, since the resistance increasing portion is formed on a part of the contact surface of at least one of the shift claw and the passive protrusion portion, the rotation resistance of the change lever is increased. As a result, the feeling of moderation when the rider operates the change pedal is increased, and the accuracy of the shift operation is improved.

In the present invention, the contact surfaces at at least one of the shift claw and the passive protrusion have a first contact portion that has a different curvature from each other and that comes into contact with the first contact portion and a second contact portion that comes into contact with the second contact portion. It is preferable that the boundary portion between the two contact portions and the second contact portion having a small curvature form the resistance increasing portion. According to this configuration, it is possible to increase the sense of moderation when operating the change pedal with a simple structure that only changes the curvature of the contact surface. Further, since at least one of the first contact portion and the second contact portion is formed of a curved surface, deformation and damage of the contact surface are suppressed.

When a first contact portion and a second contact portion having different curvatures are provided, the first contact portion on the contact surface of the passive protrusion is a curved surface, and the second contact portion is a flat surface. Is preferable. According to this configuration, it is possible to increase the sense of moderation when operating the change pedal with a simple structure that only forms a flat surface on the passive protrusion.

When a first contact portion and a second contact portion having different curvatures are provided, the first contact portion and the second contact portion of the contact surface on at least one of the shift claw and the passive protrusion are arcs. It is preferably a surface. According to this configuration, since the contact surface is formed by two arcuate surfaces, it is easy to manufacture the shift claw and the passive protrusion.

In the present invention, it is preferable that the resistance increasing portion is a protrusion formed on a part of the contact surface of the passive protrusion. According to this configuration, the main body portion excluding the protrusions in the passive protrusion can be made to have the same shape as the conventional one, so that the sense of moderation can be increased without reducing the cross-sectional area of the passive protrusion.

In the present invention, it is preferable that the resistance increasing portion is a recess formed in a part of the contact surface of the shift claw. According to this configuration, the passive protrusion pressed by the shift claw can have a simple columnar shape. As a result, an increase in the manufacturing cost of the change cam is suppressed.

In the present invention, it is preferable that the passive protrusion on which the resistance increasing portion is formed is a passive protrusion that is pressed by the shift claw when shifting to neutral. Generally, the change pedal has a low sense of moderation when shifting to neutral, but according to this configuration, an appropriate sense of moderation can be given even when shifting to neutral.

According to the change mechanism of the transmission of the present invention, the sense of moderation when the rider operates the change pedal is increased, so that the accuracy of the shift operation is improved.

It is a side view which shows the central part of the motorcycle which provided the change mechanism of the transmission which concerns on 1st Embodiment of this invention. It is a rear view which shows the change mechanism. It is a perspective view which shows the change mechanism. It is a side view which shows the lever body of the change lever of the change mechanism. It is a side view which looked at the slide plate of the change lever from the inside. It is a side view which shows the change cam of the change mechanism. It is a side view which shows the change mechanism. It is a side view explaining the rotation of the change cam. It is a side view at the time of the neutral of the change cam. It is an enlarged view of the main part of FIG. It is a side view which shows the part of the change cam of the change mechanism of the transmission which concerns on 2nd Embodiment of this invention in an enlarged manner. It is a side view which shows the part of the change cam of the change mechanism of the transmission which concerns on 3rd Embodiment of this invention enlarged. It is a side view which shows the part of the change cam of the change mechanism of the transmission which concerns on 4th Embodiment of this invention in an enlarged manner.

Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a side view showing a main part of a motorcycle provided with a change mechanism for a transmission according to a first embodiment of the present invention. In the present embodiment, the front and rear directions in the front-rear direction refer to the forward and reverse directions of the vehicle, respectively. Further, the left-right direction is the vehicle width direction, and the "right side" and the "left side" mean the "right side" and the "left side" as seen from the driver in the vehicle, respectively.

In FIG. 1, the engine E is mounted near the center of the body frame FR of the motorcycle in the front-rear direction, and the transmission 1 is housed in the latter half of the engine case EC in which the crankcase and the transmission case are integrated. The change pedal 4 is rotatably supported around a change shaft 20 that also serves as a pedal support shaft attached to the left outer side of the engine case EC. Immediately after the change shaft 20, a footrest 5 attached to the vehicle body frame FR is arranged. During running, the rider puts his foot on the footrest 5 and operates the change pedal 4 with his left foot when making a shift change.

FIG. 2 is a rear view of the change mechanism as viewed from the rear of the vehicle body. The change mechanism 2 that operates the transmission 1 rotates the change drum 6 in conjunction with the operation of the change pedal 4 by the rider, and is engaged with the spiral cam groove 6a formed on the outer periphery of the change drum 6. The shift fork 8 is moved along the axial direction (vehicle width direction) of the shift shaft 10. As the shift fork 8 moves, the shifting operation of the transmission 1 is performed. That is, the rotation of the engine E input to the input shaft 14 of the transmission 1 is changed and output to the output shaft 16. A power transmission member 18 such as a chain is connected to the output shaft 16 of the transmission 1, and the rear wheels 19 (FIG. 1) are driven via the power transmission member 18.

The change mechanism 2 is connected to a change shaft 20 in which the change pedal 4 is connected to one end (left end) 20a in the vehicle width direction and extends in the vehicle width direction, and to the other end (right end) 20b in the vehicle width direction of the change shaft 20. It has a change lever 22 and a change cam 24 that is interlocked with the change lever 22 and rotates integrally with the change drum 6. The change shaft 20 is rotatably supported by the engine case EC.

The change lever 22 rotates in conjunction with the operation of the change pedal 4, and intermittently rotates the change cam 24. Specifically, as shown in FIG. 3, the change lever 22 has a shift claw 26, the change cam 24 has a passive protrusion 28 called a pin, and the shift claw 26 presses the passive protrusion 28. By doing so, the rotation of the change cam 24 is generated. Details of the shift claw 26 and the passive protrusion 28 will be described later.

The change mechanism 2 further includes a stopper member 30 that regulates the rotation range of the change lever 22, and a position lever 32 that holds the change cam 24 at a predetermined rotation position.

The change lever 22 has a lever body 34 in which a base end portion (front end portion) 34a is fixed to a change shaft 20, and a slide plate 36 in which a pair of shift claws 26 are formed on the tip end portion 36a. The lever body 34 of the change lever 22 is fixed to the change shaft 20 by welding, for example, and rotates together with the change shaft 20. The lever body 34 and the slide plate 36 are shown in FIGS. 4 and 5, respectively.

A fitting hole 34aa is formed in the base end portion 34a of the lever main body 34, and rivet holes 34ba and 34ca are formed in the rear end portion (tip portion) 34b and the intermediate portion 34c, respectively. The change shaft 20 shown in FIG. 3 is fitted and fixed to the fitting hole 34aa, and the stepped rivet 35 is fixed to the rivet holes 34ba and 34ca in a state of protruding outward (right side) in the vehicle width direction. .. The slide plate 36 of the change lever 22 is slidably supported by two rivets 35 and 35 in the longitudinal direction (in the front-rear direction in the state of FIG. 3) with respect to the lever body 34. The slide plate 36 shown in FIG. 5 is made of sheet metal, and the shift claw 26 is formed by bending the slide plate 36 inward in the vehicle width direction inward at the tip portion 36a in a U shape. Two shift claws 26 are provided so as to be separated from each other in a direction orthogonal to the longitudinal direction (vertical direction in FIG. 5).

A locking portion mounting hole 33 is provided between the two rivet holes 34ba and 34ca in the lever body 34 of FIG. As shown in FIG. 3, a spring locking portion 45 projecting outward (right side) in the vehicle width direction is fixed to the locking portion mounting hole 33, and the winding spring 44 is wound around the spring locking portion 45. There is. The spring locking portion 45 of the present embodiment is made of a stepped rivet. Both ends of the winding spring 44 are respectively locked in two locking holes 46 provided in the slide plate 36. A spring force is constantly applied to the change cam 24 side of the slide plate 36 by the winding spring 44. Further, as shown in FIG. 5, the slide plate 36 is formed with a slide hole 41 that is long in the front-rear direction and a guide leg 43 that slides into contact with the front rivet 35 (FIG. 3) to guide the movement of the slide plate 36. ing.

The change cam 24 is fixed to the right end surface of the change drum 6 by a bolt 37. The change cam 24 has a plurality of passive protrusions 28 formed at equal intervals in the circumferential direction. The change cam 24 rotates intermittently when the passive protrusion 28 is pressed by the shift claw 26. As shown in FIG. 6, in the present embodiment, six passive protrusions 28 are formed on the change cam 24. Five of the six passive protrusions 28 have a cylindrical shape. The remaining one passive protrusion 28A has a flat surface 48 obtained by cutting a part of the outer peripheral surface of the cylinder along the axial direction of the cylinder.

In this embodiment, a pair of flat surfaces 48 are provided so as to face each other in the circumferential direction. Further, in the present embodiment, the passive protrusion 28A having the flat surface 48 is the passive protrusion 28A pressed by the shift claw 26 when shifting to neutral. Details of the flat surface 48 will be described later.

Further, a first positioning recess 40 in which the positioning roller 38 (FIG. 7) described later of the position lever 32 is engaged is formed on the radial outer side of each passive protrusion 28 in the change cam 24. Further, a second positioning recess 42 is formed between two specific adjacent passive protrusions 28. The second positioning recess 42 is adjacent to the passive protrusion 28 having the flat surface 48 in the circumferential direction (right side in FIG. 6) and the passive protrusion 28 adjacent to the circumferential direction (right side in FIG. 6). It is formed between the passive protrusion 28 and the passive protrusion 28. When the gear of the transmission 1 (FIG. 1) is in neutral, the positioning roller 38 engages with the second positioning recess 42.

The amount of the second positioning recess 42 is smaller than that of the first positioning recess 40. In other words, the height of the mountain that the positioning roller 38 engaged with the second positioning recess 42 gets over at the time of shift change is smaller than the height of the mountain of the first positioning recess 40.

The position lever 32 on the upper side of the change cam 24 shown in FIG. 3 is rotatably attached to the lever body 54 whose base end is supported by the support boss 52 in the engine case EC by the bolt 50 and the tip of the lever body 54. It has the positioning roller 38 that is supported. The support boss 52 is composed of a large-diameter cylindrical protrusion with a head protruding outward (right side) in the vehicle width direction, and a spring member 55 is wound around the outer circumference of the support boss 52. One end 55a of the spring member 55 is locked to the lever body 54, and the spring member 50 constantly applies a spring force toward the outer peripheral surface of the change cam 24 to the lever body 54 and the positioning roller 38.

The lower stopper member 30 is made of a shaft body, and is fixed in the engine case EC by a screw portion 30a at one end (inner end in the vehicle width direction) thereof. The shaft portion 30b of the other end of the stopper member 30 (outer end in the vehicle width direction) is inserted into a long hole 56 formed in the lever body 34 of the change lever 22. The elongated hole 56 has a shape having a play corresponding to the swing stroke of the change lever 22 with respect to the shaft portion 30b of the stopper member 30 inserted therein. When the change lever 22 rotates around the axis of the change shaft 20 in conjunction with the operation of the change pedal 4 (FIG. 2), the range of the change lever 22 is regulated by the elongated hole 56 and the stopper member 30. ..

A return spring 58 is wound around the outer circumference of the other end 20b of the change shaft 20 in the vehicle width direction. The return spring 58 is wound around a boss 60 with a collar 60a fitted to the other end 20b of the change shaft 20 in the vehicle width direction, and both end portions 58a and 58a are stopper members as shown in FIG. The shaft portion 30b of the 30 extends in parallel so as to be pressed against each other in the radial direction thereof. As a result, the stopper member 30 is given a force by the spring force of the return spring 58 so as to always return to the intermediate portion (position in FIG. 7) of the elongated hole 56.

Next, the shifting operation of the transmission 1 by the changing mechanism 2 will be described. When the rider operates the change pedal 4 of FIG. 2, the change lever 22 rotates via the change shaft 20. Specifically, the change lever 22 rotates in the direction of arrow A shown in FIG. At that time, the shift claw 26 of the change lever 22 presses the passive protrusion 28 of the change cam 24, and the change cam 24 rotates intermittently. When shifting up, the upper shift claw 26 presses the passive protrusion 28 to rotate the change cam 24 counterclockwise, and when shifting down, the lower shift claw 26 presses the passive protrusion 28 to change. Rotate the cam 24 clockwise.

The rotation of the change lever 22 and the change cam 24 will be described with reference to FIG. Before the shifting operation is performed, the positioning roller 38 of the position lever 32 and the shift claw 26 of the change lever 22 are at the positions of the solid lines in FIG. 8A. When the change lever 22 rotates in the direction of arrow A1 from this state, the shift claw 26 of the change lever 22 moves to the position of the alternate long and short dash line and comes into contact with the outer peripheral surface of the passive protrusion 28 of the change cam 24. Only one of the shift claws 26 is shown.

When the change lever 22 further rotates in the direction of arrow A1 from the state of the two-point chain line in FIG. 8 (a), the shift claw 26 presses the passive protrusion 28 in the direction of arrow A1 and the arrow A1 is shown in FIG. 8 (b). As shown by, the change cam 24 is rotated, the change cam 24 and the change drum 6 are rotated counterclockwise by one pitch in the upshift direction, and the combination of the transmission gears of the transmission 1 (FIG. 2) is changed.

When the shift is completed, the positioning roller 38 of the position lever 32 gets over the mountain portion of the change cam 24 and fits into the next first positioning recess 40. Further, the change lever 22 moves in the direction of arrow A2 due to the restoring force of the return spring 58 (FIG. 7), and returns to the original state shown by the solid line from the broken line.

As described above, the shift claw 26 and the passive protrusion 28 each have a lever-side contact surface 62 and a cam-side contact surface 64 that come into contact with each other. The lever-side contact surface 62 is formed on the surfaces of the pair of shift claws 26 facing each other. The cam-side contact surface 64 is formed on substantially the entire outer peripheral surface of the five cylindrical passive protrusions 28 except for the inner surface in the radial direction. That is, the curvature of the cam-side contact surface 64 is substantially constant in the five cylindrical passive protrusions 28.

In one passive protrusion 28A having a flat surface 48, the cam-side contact surface 64 has a pair of flat surfaces 48, 48 and a radial outer curved surface 65 connecting the two flat surfaces 48, 48. ing. That is, the cam-side contact surface 64 has a first contact portion and a second contact portion having different curvatures from each other. Specifically, the curved surface 65 of the cam-side contact surface 64 of the passive protrusion 28 constitutes a first contact portion that comes into contact prior to the shift claw 26 at the time of shift change, and a flat surface 48 having a small curvature follows. It constitutes a second contact portion that comes into contact with each other. The first and second contact portions 65, 48 are connected via a boundary portion 66.

FIG. 9 shows the positions of the positioning roller 38 of the position lever 32 and the shift claw 26 of the change lever 22 in the neutral position. The transmission 1 of the present embodiment is shifted up in the order of 1st speed, neutral, 2nd speed, 3rd speed, 4th speed, 5th speed, and 6th speed, but the speed change to neutral is a speed change from 1st to 6th speed. The operations of the change lever 22 and the change cam 24 are different.

As described above, the height of the mountain that the positioning roller 38 gets over at the time of shift change is smaller in the second positioning recess 42 than in the first positioning recess 40. Moreover, while the first positioning recess 40 is formed on the radial outer side of the passive protrusion 28, the second positioning recess 42 is formed between the two adjacent passive protrusions 28, 28. That is, the amount of rotation when shifting to neutral can be smaller than the amount of rotation when shifting to 1st to 6th gear.

In this way, since the mountain that the positioning roller 38 gets over is low and the amount of rotation is small, it is not fixed to neutral when the shift is changed from the 1st speed to the 2nd speed or from the 2nd speed to the 1st speed (the positioning roller 38 It is not held in the second positioning recess 42), and a shift change is often performed. This is because the feeling of moderation when the rider operates the change pedal 4 is small. If the sense of moderation is small, it is difficult to accurately fix it in neutral.

As shown in FIG. 9, when in neutral, the positioning roller 38 of the position lever 32 is engaged with the second positioning recess 42 of the change cam 24. The shift claw 26 of the change lever 22 has its lever-side contact surface 62 in contact with the cam-side contact surface 64 of the passive protrusion 28A, specifically, the flat surface 48.

When the shift is changed to neutral, as shown by the alternate long and short dash line in FIG. 10, which is an enlarged view, the lever-side contact surface 62 of the shift claw 26 of the change lever 22 first has a cam-side contact surface of the passive protrusion 28. It contacts the curved surface 65 (first contact portion) of 64. From this state, when the change lever 22 further rotates in the direction of arrow A1, the shift claw 26 of the change lever 22 is in the direction of arrow B while its lever-side contact surface 62 is in contact with the curved surface 65 of the passive protrusion 28. Rotates to.

Further, as the rotation of the change lever 22 in the A1 direction progresses, the lever-side contact surface 62 of the shift claw 26 contacts the flat surface 48 (second contact portion) via the boundary portion 66 (FIG. 10). The state shown by the solid line) is shifted to neutral, and the state shown in FIG. 9 is obtained. When the lever-side contact surface 62 of the shift claw 26 shifts from the curved surface 65 to the flat surface 48 beyond the boundary portion 66, the lever-side contact surface 62 of the shift claw 26 and the cam-side contact surface 64 of the passive protrusion 28 Contact resistance increases. As a result, the boundary portion 69 and the flat surface 48 (second contact portion) form a resistance increasing portion 69 that increases the rotational resistance of the change lever 22 as compared with the other portion of the contact surface.

When downshifting, the lower shift claw 26 in FIG. 7 pushes up the passive protrusion 28 of the change cam 24 to rotate the change cam 24 clockwise. The contact between the shift claw 26 and the passive protrusion 28 at that time is the same as in the case of the shift-up.

According to the above configuration, the resistance increasing portion 69 is formed on a part of the contact surface (cam side contact surface 64) with the shift claw 26 in the passive protrusion 28. Therefore, when the lever-side contact surface 62 of the shift claw 26 passes through the resistance increasing portion 69, the rotation resistance of the change lever 22 increases. As a result, the sense of moderation when the rider operates the change pedal 4 is increased, so that the accuracy of the shift operation is improved.

The resistance increasing portion 69 is formed in the passive protrusion portion 28A pressed by the shift claw 26 when shifting to neutral. In the present embodiment, the operation of the change lever 22 and the change cam 24 is different from that of the 1st to 6th gears when shifting to neutral, and when shifting to neutral, the second positioning recess for neutral in FIG. As can be seen from the fact that 42 is shallower than the other first positioning recesses 40, the sense of moderation of the change pedal tends to be low. According to the above configuration, an appropriate sense of moderation can be given even when shifting to neutral, so that the accuracy of the shift operation is improved.

Further, the cam-side contact surface 64 of the passive protrusion 28A has a curved surface 65 having a large curvature that comes into contact in advance and a flat surface 48 having a small curvature that comes into contact subsequently, and is flat with the boundary portion 66 thereof. A resistance increasing portion 69 is formed by the surface 48. In this way, with a simple structure that only changes the curvature of the contact surface 64 (forms the flat surface 48), it is possible to increase the sense of moderation when the change pedal 4 is operated. Further, since the first contact portion that comes into contact in advance is composed of the curved surface 65 having a large curvature, deformation and damage of the contact surface 64 are suppressed.

In the above embodiment, the resistance increasing portion 69 is formed on the passive protrusion 28A pressed by the shift claw 26 at the time of shifting to neutral, but the resistance increasing portion 69 is not limited to the passive protrusion 28A at the time of neutral, and any passive collision is not limited. It can be provided in the portion 28. As a result, it is possible to increase the sense of moderation when shifting to an arbitrary transmission gear.

FIG. 11 shows an enlarged view of one passive protrusion 28B of the change cam 24 of the change mechanism of the transmission according to the second embodiment of the present invention. In the second embodiment, the second contact portion of the cam-side contact surface 64 of the passive protrusion 28 is not a flat surface but an arc surface having a smaller curvature than the first contact portion (curved surface 65) formed of an arc surface. It is composed of 70. The curved surface 65 (first contact portion) and the arc surface 70 (second contact portion) are connected by a boundary portion 66 as in the first embodiment.

Also in the second embodiment, the resistance increasing portion 69 including the boundary portion 66 and the arc surface 70 is formed on the cam side contact surface 64 of the passive protrusion portion 28B, so that when the rider operates the change pedal 4. The feeling of moderation increases. Further, according to the second embodiment, since the cam-side contact surface 64 is formed by the two arcuate surfaces 65 and 70, the passive protrusion 28B can be easily manufactured.

FIG. 12 shows an enlarged view of one passive protrusion 28C of the change cam 24 of the change mechanism of the transmission according to the third embodiment of the present invention. In the third embodiment, the cam-side contact surface 64 of the passive protrusion 28C is formed on the outer peripheral surface of the cylinder, and the curvature is constant. A protrusion 72 is formed on a part of the cam-side contact surface 64 of the passive protrusion 28C, and the protrusion 72 constitutes the resistance increasing portion 69.

Also in the third embodiment, since the resistance increasing portion 69 is formed on the cam side contact surface 64 of the passive protrusion portion 28C, the feeling of moderation when the rider operates the change pedal 4 is increased. Further, according to the third embodiment, the main body portion of the passive protrusion 28C excluding the protrusion 72 can be formed into a columnar shape having the same shape as the conventional one, so that the cross-sectional area of the passive protrusion 28C is not reduced. The feeling of moderation can be increased.

FIG. 13 shows an enlarged view of one passive protrusion 28D of the change cam 24 of the change mechanism of the transmission according to the fourth embodiment of the present invention and the shift claw 26A of the change lever 22. In the fourth embodiment, the cam-side contact surface 64 of the passive protrusion 28D is formed on the outer peripheral surface of the cylinder, and the curvature is constant. A recess 74 is formed in a part of the lever-side contact surface 62 of the shift claw 26A, and the recess 74 constitutes the resistance increasing portion 69. As described above, the resistance increasing portion 69 can be formed not on the cam-side contact surface 64 of the passive protrusion 28C but on a part of the lever-side contact surface 62 of the shift claw 26A.

Also in the fourth embodiment, since the resistance increasing portion 69 is formed on the lever side contact surface 62 of the shift claw 26A, the feeling of moderation when the rider operates the change pedal 4 is increased. Further, according to the fourth embodiment, the passive protrusion 28D pressed by the shift claw 26A can have a simple columnar shape. As a result, an increase in the manufacturing cost of the change cam 24 is suppressed.

The present invention is not limited to the above embodiments, and various additions, changes, or deletions can be made without departing from the gist of the present invention. In the above embodiment, an example in which the change mechanism 2 is applied to a motorcycle has been described, but the change mechanism 2 of the present invention can also be applied to saddle-type vehicles other than motorcycles, such as tricycles and four-wheel buggies. is there. Therefore, such things are also included within the scope of the present invention.

1 Transmission 2 Change mechanism 4 Change pedal 6 Change drum 8 Shift fork 22 Change lever 24 Change cam 26, 26A Shift claw 28, 28A, 28B, 28C, 28D Passive protrusion 48 Flat surface (second contact part)
62 Lever side contact surface (contact surface)
64 Cam side contact surface (contact surface)
65 Curved surface (first contact part)
66 Boundary part 69 Resistance increasing part 70 Arc surface 72 Protrusion 74 Recess

Claims (7)

It is a change mechanism that rotates the change drum that operates the shift fork of the transmission.
A change cam that rotates integrally with the change drum,
It is equipped with a change lever that rotates in conjunction with the operation of the change pedal and intermittently rotates the change cam.
The shift claw provided on the change lever presses the passive protrusion provided on the change cam to cause rotation of the change cam.
A transmission in which a resistance increasing portion for increasing the rotational resistance of the change lever at the time of pressing is formed on a part of at least one contact surface between the shift claw and the passive protrusion portion as compared with the other portion of the contact surface. Change mechanism. In the change mechanism of the transmission according to claim 1, the contact surfaces of at least one of the shift claw and the passive protrusion come into subsequent contact with a first contact portion which has a different curvature from each other and comes into contact with the first contact portion. Has 2 contact parts
A change mechanism of a transmission in which a boundary portion between both contact portions and the second contact portion having a small curvature form the resistance increasing portion. The change mechanism for a transmission according to claim 2, wherein the first contact portion on the contact surface of the passive protrusion is a curved surface, and the second contact portion is a flat surface. In the change mechanism of the transmission according to claim 2, the change mechanism of the transmission in which the first contact portion and the second contact portion of the contact surface on at least one of the shift claw and the passive protrusion are arc surfaces. .. The change mechanism of the transmission according to claim 1, wherein the resistance increasing portion is a protrusion formed on a part of the contact surface of the passive protrusion portion.
The change mechanism of the transmission according to claim 1, wherein the resistance increasing portion is a recess formed in a part of the contact surface of the shift claw. In the change mechanism of the transmission according to any one of claims 1 to 6, the passive protrusion formed by the resistance increasing portion is a passive protrusion pressed by the shift claw when shifting to neutral. Change mechanism of transmission.