JPH06123355A - Gear shifter for motorcycle - Google Patents

Abstract

PURPOSE:To facilitate the shift to a neutral position by providing the neutral position in a specified position between first and second speed positions. CONSTITUTION:A gear shift cam operated by a shift lever is rotated stepwise in positive and reverse direction FR, whereby shift positions are successively changed, and a rotating angle holding means 37 holds the rotating angle of the gear shift cam in each shift position. The rotating angle theta1 of the gear shift cam between a first speed position and a second speed position is set larger than rotating angles theta2-theta6 between other shift positions, and neutral position is provided in 1/2 of the rotating angle theta1 between the first and second speed positions. Thus, the rotating angle holding means 37 is easily engaged with the gear shift cam in the neutral position, and the shift from the first speed or second speed to the neutral position can be easily performed without requiring experience.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a transmission for a motorcycle which facilitates shifting to a neutral position.

[0002]

2. Description of the Related Art A transmission of a motorcycle having a return type shift pattern repeats the operation of scraping up a shift lever with a toe of a foot, thereby making a first gear, a second gear and a third gear.
The gears are sequentially shifted up such as speed, and on the contrary, the gears are sequentially shifted down by repeating the operation of depressing the shift lever.

Inside the transmission, there is provided a cylindrical cam-shaped gear shift cam which rotates stepwise in forward and reverse directions by raising and lowering the shift lever, and a plurality of shift forks are operated by the rotation of the gear shift cam. , Gears have been rearranged to change gears.

The gear shift cam is provided with a rotation angle holding means 100 as shown in FIG. The rotation angle holding means 100 is generally composed of a positioning cam 102 fixed to the gear shift cam 101 so as to rotate integrally therewith, and a cam stopper 104 pivotally supported in the engine case and biased by a spring 103 or the like. A roller 105 is rotatably supported at one end of the cam stopper 104, and the roller 105 is engaged with the engaging recesses αn and α1, α2, α3 ... Formed around the positioning cam 102 by the biasing force of the spring 103. To hold the rotation angle of the positioning cam 102 (gear shift cam 101) at each shift position.

For example, in the case of a 6-speed transmission, the number of engaging recesses excluding the engaging recess αn is set to six from α1 to α6, and each of them changes from the first speed position to the sixth speed position. Correspond. These engaging recesses α1 to α6 are arranged at equal intervals along the circumference of the positioning cam 102, that is, at every 60 °, and the engaging recesses αn corresponding to the neutral position.
Is provided at an intermediate position between the engaging recesses α1 and α2.

Since the gear shift cam 101 rotates by 60 ° each time the shift lever rotates one stroke, when shifting to each gear from the first speed to the sixth speed, the shift lever is moved once to several times. Full stroke rotation over
The gear shift cam 101 is rotated by 60 ° to shift to a desired gear. To shift to neutral, the gear shift cam 10 is operated by shifting the shift lever by a half stroke after shifting to the first speed or the second speed.
1 is rotated by 30 ° so that the engaging concave portion αn of the positioning cam 102 is engaged with the roller 105 to make it neutral.

[0007]

However, as described above, the engagement recess αn of the positioning cam 102 has the engagement recess α1 corresponding to the first speed position and the engagement recess α2 corresponding to the second speed position. Since the engaging concave portion αn is provided at an intermediate position, the depth and width of the engaging concave portion αn are considerably smaller than those of the other engaging concave portions α1 to α6. There is often a case of overshifting and engaging with the engaging recess α1 or the engaging recess α2, resulting in a misshift.

In order to prevent this, it is necessary to delicately adjust the force of the toe applied to the shift lever when shifting to neutral, and it is necessary to get used to the operation.

The present invention has been made to solve this problem, and an object of the present invention is to provide a transmission for a motorcycle which can easily shift to neutral without getting used to it.

[0010]

In order to achieve the above object, a transmission of a motorcycle according to the present invention is a return type shift in which a neural position is provided between a first speed position and a second speed position. A gear shift cam, which has a pattern and is operated by a shift lever, gradually shifts in forward and reverse directions to sequentially change shift positions, and rotation angle holding means for holding the rotation angle of the gear shift cam at each shift position is provided. In the above-described motorcycle transmission, the rotation angle of the gear shift cam between the first speed position and the second speed position is made larger than the rotation angle between the other shift positions to set the first speed position and the second speed position. It is characterized in that a neutral position is provided at a position half the rotation angle between the positions.

[0011]

When the transmission of the motorcycle is constructed as described above, the rotation angle holding means is easily engaged with the gear shift cam at the neural position, so that the first speed or the second speed can be easily shifted to Newtonil. Like

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings.

FIG. 2 is a plan sectional view of a transmission for a motorcycle to which an embodiment of the present invention is applied, FIG. 3 is a perspective view of its operating portion, and FIG. 4 is an exploded perspective view of the operating portion. 1 and 5 are cross-sectional views taken along the lines I-I and V-V of FIG. 2, respectively.

The transmission 1 has a return type shift pattern in which a neutral position is provided between the first speed position and the second speed position, and is, for example, a 6-speed transmission type and an engine case 2 It is housed inside. The input shaft 3, which is rotatably supported in the engine case 2 and receives the power of the engine, is provided with drive gears A1 to A6 from the first speed to the sixth speed. The output shaft 4 which is parallel and transmits power to the rear wheels has a driven gear B which is constantly meshed with each of the drive gears A1 to A6.
1 to B6 are provided. Since FIG. 2 is a developed plan view of the transmission 1, it is shown in a state where the drive gears and the driven gears are not in mesh with each other.

In the engine case 2, a cylindrical cam-shaped gear shift cam 5 parallel to the input shaft 3 and the output shaft 4 is provided.
Is rotatably supported, and shift fork shafts 6 and 7 are installed in front of and behind it. A shift fork 8 is attached to the shift fork shaft 6, and shift forks 9 and 10 are attached to the shift fork shaft 7 so as to be slidable in the thrust direction. Pins 8a and 9 installed
a and 10a are fitted in the cam grooves 12, 13, and 14 of the gear shift cam 5, respectively.

Fork portions 8b, 9b, 10b are formed on the shift forks 8, 9, 10 respectively, and the fork portion 8b rotatably holds a shift groove 15 provided between the drive gears A3, A4. The fork portions 9b and 10b rotatably grip the shift grooves 16 and 17 provided in the driven gears B5 and B6, respectively.

Therefore, as the gear shift cam 5 rotates, the shift forks 8, 9 and 10 move so that the cam groove 1 moves.
Sliding on the shift fork shafts 6, 7 according to the shapes of 2, 13, 14 and thereby the drive gears A3, A
4 and the driven gears B5, B6 slide along the input shaft 3 or the output shaft 4 to select a combination of gears for transmitting power, and gear shifting is performed.

At the rear of the engine case 2, a shift lever 19 is fixed at one end, a shifting shaft 20 is rotatably supported, and a shift drive gear 21 is rotatably provided at the other end. . The shift drive gear 21 includes a rotation angle regulation hole 22 and a stopper 23.
And are provided. On the other hand, a stopper 24 is projectingly provided on the engine case 2, and the stopper 24 is fitted into the rotation angle regulating hole 22 so as to be shifted.
The rotation angle of is regulated. In addition, the bar 25a of the return spring 25 mounted around the shifting shaft 20
Since the stoppers 23 and 24 are sandwiched between the shift lever 19 and the shift drive gear 21, the shift lever 19 and the shift drive gear 21 are held at the neutral position N shown in FIG.

A shift driven gear 27 that meshes with the shift drive gear 21 is rotatably attached to the gear shift cam 5 about a shaft 28. As shown in FIGS. 2 and 4, a pole holder 29 is provided integrally with the shift driven gear 27 so as to rotate, and the pole holder 29 is inserted into a pole housing 30 formed in the gear shift cam 5.

As shown in FIG. 5, the pole holder 29 is
A pair of two poles 31, 32 are built in the spring while being biased by a spring 33.
Of the engaging groove 30a to 30h formed in the inner peripheral surface of the pole housing 30 is engaged with any one of the facing ends. A pole lifter 34 is fixed to the engine case 2 and the like near the pole holder 29 with screws 35 and the like.

The shift lever 19 is, for example, moved upward by 1
When the stroke is rotated, the shift drive gear 21 integrally rotates and drives the shift driven gear 27 to rotate in the forward direction F by about 60 °. The rotation of the shift driven gear 27 is transmitted to the gear shift cam 5 by the one pole 32, the gear shift cam 5 rotates 60 ° in the forward rotation direction F, and the transmission 1 is shifted up by one step. At this time, the other pole 31 is pressed by the pole lifter 34.

When the shift lever 19 is returned to the neutral position N by the force of the return spring 25, the shift driven gear 27 returns to the initial position together with the pole holder 29, but the gear shift cam 5 includes the pole 31 and the pole lifter 34. Since it was pressed by, it will not be returned to rotation and will remain in its original position.

When the shift lever 19 is rotated downward by one stroke, the shift driven gear 21 rotates about 60 ° in the reverse rotation direction R, and this rotation is transmitted to the gear shift cam 5 by the pawl 31 and the transmission 1 Is downshifted one step. At this time, since the pole 32 is pressed by the pole lifter 34, the shift lever 19
When the gear shift cam 5 returns to the neutral position N, the rotation of the gear shift cam 5 is not returned.

As described above, by rotating the shift lever 19 upward or downward by one stroke, the gear shift cam 5 is rotated stepwise in the forward and reverse directions by 60 °, and the transmission 1 is shifted up by one step. Or downshifted.

The gear shift cam 5 has a rotation angle holding means 3
7 is provided. As shown in FIGS. 1 to 4, the rotation angle holding means 37 is rotatably pivotally attached to a positioning cam 39 fixed to the gear shift cam 5 by a pin 38 or the like and a shift fork shaft 7 or the like. And a spring 41 for urging the cam stopper 40.

The roller 4 is provided at one end of the cam stopper 40.
2 is rotatably supported, and as shown in FIG. 1, the roller 42 is engaged with the engaging recesses β n and β n formed around the positioning cam 39 by the urging force of the spring 41.
The rotation angle of the gear shift cam 5 is held at each shift position by engaging with any one of 1 to β6.

When the engagement recess βn of the positioning cam 39 is engaged with the roller 42, the rotation angle of the gear shift cam 5 is held at the neutral position, and the engagement recesses β1 to β6 of the positioning cam 39 are engaged with the roller 42. Then, the rotation angles of the gear shift cam 5 are held at the first speed position to the sixth speed position, respectively. In this way, natural rotation of the gear shift cam 5 is prevented, and the gear shift 5 rotates stepwise to achieve a speed change with good moderation.

In the positioning cam 39, the central angle θ1 formed by the engaging recess β1 corresponding to the first speed position and the engaging recess β2 corresponding to the second speed position is defined between the other engaging recesses. The angles are wider than the central angles θ2, θ3, θ5, and θ6. For example, the central angle θ1 is set to 64 ° together with the opposing central angle θ4, and the other central angles θ2 and θ3 are set.
, Θ5, θ6 are set to 58 °. The central angle θ4 is set to the same angle as θ1.
The drive system of the gear shift cam 5 is the shift drive gear 21.
This is because it is a gear drive type by the shift driven gear 27. That is, depending on the drive system of the gear shift cam 5, it is not necessary to make the central angle θ4 the same as θ1.

In this way, the rotation angle of the gear shift cam 5 between the first speed position and the second speed position is made larger than the rotation angle between the other shift positions (the fourth speed position and the fifth speed position). Except for the fast position). The engaging recess βn corresponding to the neutral position is the engaging recesses β1 and β2.
Between the first gear position and the second gear position because the center angle θ1 is bisected by 32 °. Is provided with a neutral position.

With the above construction, the depth and width of the engaging recess βn can be made larger than before. Therefore, when shifting from the first speed or the second speed to the neutral position, the roller 42 of the cam stopper 40 is
Can be easily engaged with the engaging recess βn from the engaging recess β1 or β2, and can be easily shifted to neutral without requiring any habituation.

[0031]

As described above, the transmission of the motorcycle according to the present invention has the return type shift pattern in which the neural position is provided between the first speed position and the second speed position, The gear shift cam operated by the shift lever is gradually rotated in the forward and reverse directions to sequentially change the shift position, and a motorcycle provided with rotation angle holding means for holding the rotation angle of the gear shift cam at each shift position. In the transmission, the rotation angle of the gear shift cam between the first speed position and the second speed position is made larger than the rotation angle between the other shift positions, and the rotation angle between the first speed position and the second speed position is set. It is characterized in that the neutral position is provided at a position of 1/2 of the above.

Therefore, the rotation angle holding means is easily engaged with the gear shift cam at the neural position, and the gear can be easily shifted from the first speed or the second speed to the neutral position without requiring any habituation. .

[Brief description of drawings]

FIG. 1 is a view showing an embodiment of the present invention and is a cross-sectional view taken along line I-I of FIG.

FIG. 2 is a plan sectional view of a transmission for a motorcycle to which an embodiment of the present invention is applied.

FIG. 3 is a perspective view showing an operating portion of the transmission.

FIG. 4 is an exploded perspective view of an operating portion of the transmission.

5 is a cross-sectional view taken along the line VV of FIG.

FIG. 6 is a diagram showing a conventional technique.

[Explanation of symbols]

1 Transmission 2 Engine Case 5 Gear Shift Cam 6,7 Shift Fork Shaft 8,9,10 Shift Fork 19 Shift Lever 20 Shifting Shaft 21 Shift Drive Gear 27 Shift Driven Gear 37 Rotation Angle Holding Means 38 Pin 39 Positioning Cam 40 Cam Stopper 41 Spring 42 Roller F Forward direction of gear shift cam R Reverse direction of gear shift cam θ1 Rotation angle of gear shift cam between first speed position and second speed position

Claims (1)

[Claims] 1. A return type shift pattern in which a neural position is provided between a first speed position and a second speed position, and a gear shift cam operated by a shift lever is gradually rotated in forward and reverse directions. As a result, the shift position is sequentially changed, and in the transmission of the motorcycle provided with the rotation angle holding means for holding the rotation angle of the gear shift cam at each shift position, between the first speed position and the second speed position. The rotation angle of the gear shift cam is made larger than the rotation angle between the other shift positions, and the neutral position is provided at a position half the rotation angle between the first speed position and the second speed position. Transmission for motorcycles.