JP4108343B2 - Motorcycle clutch device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a clutch device for a motorcycle that transmits or blocks rotation of a crankshaft to a rear wheel side.
[0002]
[Prior art]
In general, in a wet multi-plate clutch device used for a motorcycle, an outer friction plate and an inner friction plate are alternately stacked between an outer drum connected to the crankshaft side and an inner drum connected to the rear wheel side. When the outer and inner friction plates are pressed against each other by a clutch spring with a pressure plate, the rotation of the crankshaft is transmitted to the rear wheel, and when the power transmission during a shift is cut off, the clutch is disconnected. The pressure plate is released by operating the pressure plate to move against the urging force of the clutch spring.
[0003]
This type of clutch device includes a hand-clutch type in which the clutch is disengaged by operating the clutch lever and then switched to one of the shift stages by depressing the shift pedal. There is a shift interlock type in which the clutch is disengaged in the first half and switched to one of the shift stages in the second half.
[0004]
[Problems to be solved by the invention]
However, in the above-described conventional clutch device, there is a case where the clutch is difficult to be disconnected due to sticking or dragging between the adjacent outer and inner friction plates even when the clutch is disengaged. For this reason, an unpleasant impact sound or bodily sensation shock at the time of dog engagement may occur during a shift operation. In particular, in the case of the shift interlock type clutch device, since the time from the operation to disengage the clutch to the shift is shorter than that of the hand clutch type, it is easy to generate meshing noise and shock. There's a problem.
[0005]
The present invention has been made in view of the above-described conventional situation, and when the clutch is disengaged, the friction plates are forcibly separated from each other so that the clutch can be quickly disengaged to prevent the occurrence of the meshing noise and shock. An object of the present invention is to provide a clutch device for a motorcycle.
[0006]
[Means for Solving the Problems]
According to a first aspect of the present invention, an outer friction plate that rotates together with the outer drum, an inner friction plate that rotates together with the inner drum, and an outer drum connected between the outer drum connected to the crankshaft side and an inner drum connected to the rear wheel side. Are arranged so that they can move in the axial direction alternately, and the outer and inner friction plates are pressed against each other by a pressure plate, or the pressure is released to transmit or block the rotation of the crankshaft to the rear wheel side. In such a clutch device for a motorcycle,
A separating means is provided for facilitating the separation between the adjacent outer friction plate and the inner friction plate when the press contact is released, and the separating means surrounds an extension portion extending inward from the inner peripheral edge of the inner friction plate. A plurality of extensions are formed at predetermined intervals in the direction, and each extension has a pair of elastic pieces bent so as to expand in the axial direction and in different directions, and the elasticity of adjacent inner friction plates The pieces are in contact with each other in a state of being elastically deformed with each other at the time of the pressure contact.
[0008]
[Effects of the invention]
According to the clutch device of the first aspect of the present invention, since the separating means for facilitating the separation between the adjacent outer friction plate and the inner friction plate is provided, the pressure plate releases the pressure contact by the clutch disconnection operation. When it moves, the friction plates are easily separated from each other, and sticking and dragging of the outer and inner friction plates can be prevented. As a result, the disengagement of the clutch is improved, and unpleasant meshing impact sound and bodily sensation shock during shifting can be eliminated.
[0009]
A pair of the separating means, to form at predetermined intervals an extension extending inwardly in a circumferential direction to the inner friction plate, the respective extensions, formed by bending so as to be widened in the axial direction and in a different direction of and an elastic piece, since abutted the respective elastic pieces together in an elastically deformed state with each other when pressed, when the forced friction plates are with by the reaction force due to the mutual elastic deformation between the elastic piece is released It will be separated, and sticking of friction plates can be prevented with a simple and low-cost structure without adding new parts.
[0010]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.
[0011]
FIGS. 1 to 3 are views for explaining a clutch device for a motorcycle according to an embodiment of the present invention. FIG. 1 is a cross-sectional view of an engine unit incorporating the clutch device of the present embodiment, and FIG. FIG. 3 is a sectional rear view of the device (sectional view taken along line II-II in FIG. 3), and FIG. In the present embodiment, a case where the present invention is applied to a shift interlock type wet multi-plate clutch device will be described as an example. In the present embodiment, left and right and front and rear mean left and right and front and rear as viewed from the rear of the vehicle.
[0012]
In the figure, reference numeral 1 denotes an engine unit mounted on a body frame (not shown) of a motorcycle, which integrates an air-cooled four-cycle single-cylinder engine body 1a with a clutch device 2 and a transmission mechanism 3. It has the structure.
[0013]
The engine body 1a has a cylinder head 6 connected to the upper joint surface of the cylinder block 5, a head cover 7 attached to the cylinder head 6, and a crankcase 8a and a transmission case 8b attached to the lower joint surface of the cylinder block 5. An integrated unit case 8 is connected, and a clutch cover 9 is attached to the right mating surface of the unit case 8.
[0014]
A piston 10 is slidably inserted into a cylinder bore 5 a of the cylinder block 5, and the piston 10 is connected to a crank pin 12 a of a crankshaft 12 by a connecting rod 11, and is connected to a combustion recess 6 a of the cylinder head 6. A spark plug 13 is inserted. A chain chamber 14a is formed on the left side of the cylinder block 5 and the cylinder head 6 to communicate the inside of the crankcase 8a with the inside of the cylinder head 6. A cam shaft (not shown) is connected to the chain chamber 14a by a crankshaft 12. A timing chain 14 that opens and closes the intake and exhaust valves is provided.
[0015]
The crankshaft 12 is supported by bosses 8 c and 8 d formed on the split surface of the unit case 8 via bearings 15 and 15. A generator 16 is attached to the left end of the crankshaft 12, and a centrifugal clutch 17 is attached to the right end.
[0016]
The centrifugal clutch 17 rotatably supports the output side drum 22 via the one-way clutch 21 by the boss portion 20a of the input side drum 20 splined to the crankshaft 12, and decelerates to the output side drum 22. A small gear 24 is coupled, and a plurality of weights 23 are pivotally supported on the input side drum 20. When the crankshaft 12 exceeds a predetermined rotational speed, the weight 23 is joined to the output drum 22 by centrifugal force (see the portion below the crankshaft line in FIG. 1), and the rotation of the crankshaft 12 is reduced with a small gear. 24.
[0017]
The transmission mechanism 3 includes an input shaft 25 having first, second, and third speed input gears 27, 28, and 29 attached to the rear of the crankshaft 12, and first and second rear of the input shaft 25. , The output shaft 34 on which the third speed output gears 30, 31, 32 are mounted is arranged in parallel with the crankshaft 12, and the input shaft 25 and the output shaft 34 are connected to the bearings 35, by the bosses of the transmission case 8b. The structure is supported via 36. A drive sprocket 37 is mounted on the left outer end of the output shaft 34, and the drive sprocket 37 is connected to a driven sprocket of a rear wheel (not shown) by a chain 38.
[0018]
The first speed input gear 27 is integrally formed with the input shaft 25 and meshes with a first speed output gear 30 mounted on the output shaft 34 so as to be relatively rotatable. The second speed input gear 28 is splined to the input shaft 25 so as to be movable in the axial direction, and meshed with a second speed output gear 31 mounted on the output shaft 34 so as to be relatively rotatable. The third speed input gear 29 is attached to the input shaft 25 so as to be relatively rotatable, and meshes with a third output gear 32 that is spline-fitted to the output shaft 34 so as to be movable in the axial direction.
[0019]
A shift fork (not shown) is engaged with the second speed input gear 28 and the third speed output gear 32. Then, by depressing a shift pedal (not shown), the shift fork moves either the second speed input gear 28 or the third speed output gear 32 in the axial direction to switch between the first speed and the third speed. Is done.
[0020]
A kick shaft 40 is disposed behind the output shaft 34 in parallel with the crank shaft 12, and a kick arm 41 is mounted on the right outer end of the kick shaft 40. A kick small gear 42 that meshes with a large gear 30a formed integrally with the first speed output gear 30 is attached to the left end portion of the kick shaft 40 so as to be relatively rotatable. When the kick arm 41 is stepped on, the kick shaft 40 rotates and the ratchet 43 moves in the axial direction and meshes with the kick gear 42, whereby the rotation of the kick shaft 40 is transmitted to the crank shaft 12.
[0021]
The clutch device 2 is coaxially arranged at the right end portion of the input shaft 25, and includes an outer drum 46 and an inner drum 47 coupled with a large reduction gear 45 that meshes with the reduction small gear 24 on the crankshaft 12 side. The five outer friction plates 48 and the four inner friction plates 49 are alternately stacked on each other, and the pressure plate 50 is spring-biased to the left in the drawing, thereby the inner drum 47 and the pressure plate 50 are Thus, the outer and inner friction plates 48 and 49 are pressed against each other, or the pressure plate 50 is moved to the right in the figure against the spring to release the above-mentioned pressure contact.
[0022]
The reduction large gear 45 has a cylindrical boss portion 45a rotatably mounted on the input shaft 25 with a collar 44a and a bearing bush 44b interposed therebetween. The outer drum 46 has a damper 51 attached to the reduction large gear 45. Are connected through. As a result, the outer drum 46 rotates together with the large reduction gear 45 and is connected to the crankshaft side.
[0023]
A release rod 53 is inserted into the axial hole 25a of the input shaft 25 so as to be movable in the axial direction. A pressure rod 54 is inserted into the right end portion of the shaft hole 25 a of the input shaft 25 so as to contact the release rod 53. The pressure rod 54 extends rightwardly through the shaft center of the pressure plate 50, and is supported by a recess 9a formed in the clutch cover 9 so as to be slidable in the axial direction via a seal member 59. ing. A flange 45 a that abuts against the inner wall surface of the pressure plate 50 is formed at the axial center of the pressure rod 54.
[0024]
A push lever 60 connected to the shift pedal is in contact with the left end surface of the release rod 53. When the shift pedal is depressed, the push lever 60 moves the pressure plate 50 to the right in the figure via the release rod 53 and the pressure rod 54 in conjunction with the depression, and the clutch is disengaged. In the second half, the shift fork described above shifts the shift by moving either the second speed input gear 28 or the third speed output gear 32 in the axial direction.
[0025]
The outer drum 46 has a generally bowl-like shape that opens to the right by integrally forming a bottom wall 46b with an outer peripheral wall 46a. Split grooves 46c extending in the axial direction are formed in the outer peripheral wall 46a with a predetermined angular interval, and formed in the respective split grooves 46c with a predetermined angular interval in the outer periphery of each outer friction plate 48. The convex portion 48a is engaged. The outer friction plates 48 are disposed so as to be axially spaced from each other and movable in the axial direction, and rotate together with the outer drum 46.
[0026]
Grooves 48b extending in the radial direction are formed on both friction surfaces of each outer friction plate 48 at a predetermined angular interval in the circumferential direction, and both ends of each groove 48b are the outer peripheral edges of the outer friction plate 49. , Open to the inner periphery. Each of the grooves 48b serves to prevent the friction coefficient from being stabilized and worn in a half-clutch state or the like by supplying lubricating oil to the contact surfaces of the outer and inner friction plates 48 and 49 in a distributed manner.
[0027]
The inner friction plate 49 is disposed between the outer friction plates 48 so as to be movable in the axial direction. Each inner friction plate 49 has a concave portion 49a formed on the inner peripheral surface thereof at a predetermined angular interval, and a convex portion 47b formed on the outer peripheral boss portion 47a of the inner drum 47 at a predetermined angular interval. Are rotated together with the inner drum 48.
[0028]
The inner drum 47 is disposed in the outer drum 46 and has a flange portion 47c with which the outer friction plate 48 abuts at the outer peripheral end portion. The inner peripheral boss portion 47d is spline-fitted to the input shaft 25. It is fastened and fixed by a lock nut 52 so that it cannot move in the axial direction. As a result, the inner drum 47 rotates together with the input shaft 25 and is connected to the rear wheel side.
[0029]
The pressure plate 50 is disposed so as to be coaxial with the inner drum 47, and the outer peripheral portion 50a faces the flange portion 47c of the inner drum 47 with the outer and inner friction plates 48 and 49 interposed therebetween. Are arranged as follows.
[0030]
Four pressure receiving tube portions 50b are integrally formed on the pressure plate 50 at intervals of 90 degrees, and a boss portion 47e formed integrally with the inner drum 47 is coaxial in each spring receiving tube portion 50b. It is inserted and placed to make it. A spring seat 63 is fastened to each boss portion 47e by a bolt 64, and a clutch spring 62 is interposed between the spring seat 63 and the bottom wall of the spring receiving tube portion 50b. The clutch spring 62 constantly urges the pressure plate 50 toward the flange portion 47 c of the inner drum 47. As a result, the outer and inner friction plates 48 and 49 are sandwiched between the flange portion 47c of the inner drum 47 and the outer peripheral portion 50a of the pressure plate 50 and are pressed against each other.
[0031]
The clutch device 2 is provided with a separating means for facilitating the separation between the adjacent inner friction plate 49 and the outer friction plate 48 when the press contact is released. Specifically, the separation means has the following structure.
[0032]
An extension portion 49b is integrally formed on the inner peripheral edge of the inner friction plate 49 so as to be positioned at a predetermined angle (for example, 90 degrees) interval and between the spring receiving tube portions 50b and radially inward. Has been. Each of the extending portions 49b has a pair of elastic pieces 49b 'formed by making a cut in the middle in the longitudinal direction by taking advantage of the characteristics made of an iron-based material, and each of the elastic pieces 49b', 49b. 'Is bent so as to expand in directions different from each other in the direction of the input shaft 25.
[0033]
The elastic pieces 49b 'of the adjacent inner friction plates 49 are set to have a bending height larger than half of the outer friction plate when free, so that they are elastically deformed and brought into contact with each other when pressed. The elastic pieces 49 b ′ at both the left and right ends are in contact with support seats 47 g and 50 g formed integrally with the inner drum 47 and the pressure plate 50. That is, the elastic pieces 49b 'are in contact with the adjacent elastic piece 49b' one after another from the left end support portion 47g, and are continuously in contact with the right end support seat 50g.
[0034]
Next, the effect of this embodiment is demonstrated.
[0035]
In the clutch connected state, the outer and inner friction plates 48 and 49 are sandwiched and pressed between the pressure plate 50 and the inner drum 47 by the urging force of the clutch spring 62. As a result, the rotation of the crankshaft 12 is transmitted from the centrifugal clutch 17 to the input shaft 25 of the transmission mechanism 3 via the outer drum 46, outer, inner friction plates 48 and 49, and inner drum 47, and via the output shaft 34 and drive sprocket 37. Is transmitted to the rear wheels.
[0036]
When the clutch is disengaged, the release lever 53 and the pressure rod 54 are moved to the right in the figure by the push lever 60 by depressing the shift pedal, whereby the pressure plate 50 is moved to the right in the figure against the spring force of the clutch spring 62. The pressure contact between the pressure plate 50 and the inner drum 47 is released, and thus the clutch is disengaged. Following this clutch disengagement operation, the gear is switched to any shift stage.
[0037]
At the time of clutch disengagement, when the pressure contact is released as the pressure plate 50 moves, the inner friction plates 49 are connected to each other by the reaction force between the elastic pieces 49b 'of the extension portions 49b of the inner friction plates 49. Are separated, and all adjacent inner and outer friction plates 48 and 49 are easily separated from each other.
[0038]
As described above, according to the present embodiment, the extension portions 49b extending inwardly are formed integrally with each inner friction plate 49 at a predetermined interval, and the elastic pieces 49b ′ of the extension portions 40b are elastically deformed with each other when pressed. When the pressure plate 50 is moved in the releasing direction by the clutch disengagement operation, all the inner friction plates 49 are separated from each other by the reaction force of each other, so that all the outer and inner friction plates 48, 49 are separated. It becomes easy to space apart from each other, and sticking due to the viscosity of oil between all the adjacent friction plates 48 and 49 can be prevented. Thereby, dragging of the clutch is prevented, and unpleasant meshing noise and shock at the time of shifting can be eliminated.
[0039]
The separation means of the present embodiment has a structure in which an extension portion 49b is formed integrally with the inner friction plate 49, and a pair of elastic pieces 49b 'are bent by cutting the extension portion 49b. It is possible to prevent the friction plates from sticking to each other without adding new parts, which can be realized at low cost.
[0040]
In the above embodiment, each inner friction plate 49 is formed with an extension 49b in a bifurcated shape, the elastic pieces 49b 'are brought into contact with each other, and the elastic pieces 49b' at both ends are supported by the support seats 47g, 50g. However, the extension of the present invention is not limited to this.
[0043]
In or above embodiment, taken clutch device of the shift interlock type as an example, the present invention can of course also applicable to a clutch device of the hand clutch type.
[0044]
Here, in the clutch device of the hand clutch type, when reducing the size of the clutch, it is effective to increase the amount of lubricating oil in order to prevent seizure at the time of half-clutch. However, when the amount of lubricating oil is increased, there is a concern that sticking between friction plates becomes remarkable, and clutch disengagement worsens. On the other hand, in the present invention, the outer and inner friction plates can be reliably separated from each other. Therefore, even when the amount of the lubricating oil is increased, the clutch can be disengaged well, and the size can be reduced.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view of an engine unit incorporating a motorcycle clutch device according to an embodiment of the present invention.
FIG. 2 is a sectional rear view of the clutch device (a sectional view taken along line II-II in FIG. 3).
FIG. 3 is a sectional side view of the clutch device (a sectional view taken along line III-III in FIG. 2).

Claims (1)

Between the outer drum connected to the crankshaft side and the inner drum connected to the rear wheel side, the outer friction plate rotating with the outer drum and the inner friction plate rotating with the inner drum are alternately and axially moved. A clutch for a motorcycle that is arranged in such a manner that the outer and inner friction plates are pressed against each other by a pressure plate, or the rotation of the crankshaft is transmitted to or cut off from the rear wheel by releasing the pressure contact. In the device
A separating means is provided for facilitating the separation between the adjacent outer friction plate and the inner friction plate when the press contact is released, and the separating means surrounds an extension portion extending inward from the inner peripheral edge of the inner friction plate. A plurality of extensions are formed at predetermined intervals in the direction, and each extension has a pair of elastic pieces bent so as to expand in the axial direction and in different directions, and the elasticity of adjacent inner friction plates The clutch device for a motorcycle, wherein the pieces are in contact with each other in a state of being elastically deformed at the time of the press contact .

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