Title of Invention

MOTORCYCLE CLUTCH DEVICE

Abstract

A motorcycle clutch device 1 is attached to a second shaft 2 that is located in parallel with a first shaft 31 coaxial with a crankshaft of the engine. The device 1 transmits power to a transmission and is forced to interrupt power transmission by the operation of a release mechanism 4. The device 1 includes a clutch housing 5, a disc rotary member 35 a clutch part 6, a pressure plate 7, a lever plate 8. a centrifugal element 9. and the release mechanism 4. The clutch housing 5 is rotatably supported by the second shaft 2 and to which the power is input from the first shaft 31. The disc rotary member 3 is located within the clutch housing 5 and is connected to the second shaft 2. The clutch part 6 has a plurality of plate members 14,15 to transmit and to interrupt selectively the power between the clutch housing 5 and the rotary member. The pressure plate 7 presses the plate members of the clutch part 6 against each other. The lever plate 8 is in contact with the pressure plate 7 and has a plurality of levers 8e. The centrifugal element 9 is attached to the lever 8e of the lever plate 8 and presses the lever plate 8 toward the pressure plate 7 by the centrifugal force according to the rotation of the lever plate 8. The release mechanism 4 releases the pressure of the lever plate 8 to the pressure plate 7.

Full Text

[Title of Document] Specification [Title of the invention] Motorcycle clutch device [Technical field] [0001] The present invention relates to a clutch device, particularly to a motorcycle clutch device that can transmit power from an input member to an output member and can be forced to interrupt power transmission by the operation of a release mechanism [Background art] [0002] In many cases, a centrifugal clutch is used for a motorcycle clutch device. In the centrifugal clutch device, when the power from the engine is transmitted to the centrifugal clutch device, the centrifugal force moves the centrifugal elements radially outward to engage with a clutch housing and so on, thereby transmitting the power from the input shaft to the output shaft (see Patent Document 1). [0003] Also, some of the centrifiisal clutch devices include a release mechanism that forces the clutch to interrupt the power. The centrifugal clutch device having the release mechanism includes a multi-plate clutch and centrifugal elements such that the operation of the centrifugal elements presses the multi-plate clutch, thereby engaging the clutch in a power transmitting state. On the other hand when a release mechanism forces the centrifugal elements to move away from the multi-plate clutch, the clutch is disengaged in a power interrupting state. [0004] The centrifugal clutch device is attached to a first shaft so that the clutch can obtain enoueh centriftigal force for clutch engagement because the number of revolutions of the first shaft is high. Patent Document 1 Unexamined Patent Publication H6-280901 [Disclosure of Invention] [Problems to be solved by the invention] [0005] In the above described centrifugal clutch device, when shifting gears, the release mechanism forces the centrifugal elements to separate from an associated member such as a clutch housing so that the clutch changes to a power interrupting state. Then, after shifting gears, the clutch changes again to a power transmitting state. In the power transmitting state, however, the number of revolutions of the centrifugal elements is high and shock during clutch engagement is likely to be large, because the clutch device is attached to the first shaft to which the power is directly transmitted from the engine. [0006] It is an object of the present invention to reduce shock during clutch engagement when shifting gears in a centrifugal motorcycle clutch device that can compulsorily release the clutch encasement. [Means for sohdng problems] [0007] A motorcycle clutch device according to a first aspect of the present invention can be attached to a second shaft located in parallel with a first shaft coaxial with a crankshaft of an engine. The device can transmit power to a transmission and can be forced to interrupt power transmission by the operation of a release mechanism. The device includes a clutch housing, a disc-like rotary member, a clutch part, a pressure plate, a lever plate, a centrifugal element, and a release member. The clutch housing can be rotatably supported by the second shaft and to which power can be input from the first shaft. The disc-like rotary member is located within the clutch housing and can be connected to the second shaft. The clutch part selectively transmits and interrupts the power between the clutch housing and the rotary member. The pressure plate presses the clutch part. The lever plate is in contact with the pressure plate and has a plurality of levers. The centrifugal element is attached to the lever of the lever plate to press the lever plate toward the pressure plate by centrifugal force according to the rotation of the lever plate. The release member releases the pressure of the lever plate to the pressure plate. [0008] In this clutch device, when the power of the engine is transmitted from the first shaft to the second shaft via the clutch housing and so on. the lever plate is rotated. Accordingly, the centrifugal element which is attached to the lever plate, is operated by centrifugal force to move the pressure plate toward the clutch part. As a result the clutch part changes to a power transmitting state. In this state, the power from the second shaft is transmitted to the output member via the clutch part [0009] Since the clutch part is attached to the second shaft whose number of revolutions is relatively low. shock during clutch engagement can be reduced. [0010] A motorcycle clutch device according to a second aspect of the present invention is the device of the first aspect wherein the lever plate is a diaphragm spring having a plate part at a radially outer portion thereof and a lever part made of a plurality of levers extending radially inward from the plate part. [0011] In this clutch device, since the lever plate is a diaphragm spring, by setting it such that the lever plate does not press the clutch part when the centrifugal force is not applied to the centrifugal element a return spring or other member to return the lever plate to a clutch disengagement position is not required. Additionally, a return spring is not required to return the lever plate to the original position after the release member operates the lever plate. [0012] A motorcycle clutch device according to a third aspect of the present invention is the device of the second aspect wherein the lever plate is constructed such that a radially outer end of the plate part is supported by the clutch housing, and a radially inner end of the lever part is supported bv the release member. The radially inner end of the lever part is located closer to the clutch part than the radially outer portion of the plate part [0013] In this device, the clutch device can be scaled down by shortening the axial dimension. [0014] A motorcycle clutch device according to a fourth aspect of the present invention is the device of the third aspect, wherein the centrifugal element is attached to the lever in a position closer to the clutch part than the radially outer portion of the plate part supported by the clutch housing. [0015] In this device, the rotation of the lever plate causes the centrifugal element to press the lever plate toward the centrifugal clutch part [0016] A motorcycle clutch device according to a fifth aspect of the present invention is the device of the first aspect, wherein the centrifugal element is a plate member that is wound around at least one of the levers of the lever plate. [0017] In this device, the present invention can be implemented with a simple structure. [0018] A motorcycle clutch de\ice according to a sixth aspect of the present invention is the device of the fourth aspect, wherein the pressing load to the clutch part can be adjusted by changing a position where the centrifugal element is attached [0019] In this device, it is easy to change the magnitude of the pressing load to the clutch part [Brief description of drawings] [0020] Fig. 1 is a view of showing a first shaft 31 and a drive gear 32 attached to the engine. Fig. 2 is a view of a motorcycle clutch device 1 according to one embodiment of the present invention, seen from the transmission side. [Explanations of letters or numerals] [0021] 1 motorcvcle clutch device 3 output rotary member 4 release mechanism 5 clutch housing 6 clutch part 7 pressure plate 8 diaphragm spring 9 centrifugal elements [Best mode for carrying out the invention] [0022] [Structure] Fig. 1 shows a motorcycle clutch device 1 according to one embodiment of the present invention. The clutch device 1 is attached to a second shaft 2 so that the device 1 can transmit power of the engine to the second shaft 2 and can be forced to interrupt power to the transmission by the operation of a release mechanism 4. It should be noted that the second shaft 2 is a shaft located in parallel with a first shaft 31 which is coaxial with a crankshaft of the engine. The motorcycle clutch device 1 includes a clutch housing 5, an output rotary member 3, a clutch part 6, a pressure plate 75 a diaphragm spring 8. the release mechanism 4, and centrifugal elements 9. [0023] The clutch housing 5 is rotatably supported by the second shaft 2, and, as shown in Fig. 1, has a disc part 5a, a first cylindrical portion 5b that extends from the outer periphery of the disc part 5a outward in the axial direction, (right side in Fig.l) and a second cylindrical portion 5c provided on the inner periphery of the disc part 5a having a relatively small diameter. An input gear 12, which is engaged with a drive gear 32 that is non-rotatably supported by the first shaft 31 of the engine so that the power can be input from the first shaft 31 to the input gear 12. is attached to the disc part 5a. In addition, the input gear 12 is provided with a plurality of rubber members 50 to absorb impact from the engine. The first cylindrical portion 5b has an inner circumference formed with a spline to be engaged with a clutch part 6 (later described). A one-way clutch 40. which does not transmit power from the first shaft 31 but transmits power from the second shaft 2. is located on an inner circumference of the second cylindrical portion 5c. The second cylindrical portion 5c is supported by the second shaft 2 via the one-way clutch 40. [0024] The output rotary member 3 is a member that is located within the clutch housing 5 and is connected to the second shaft 2. The output rotary member 3 is approximately disc-like in form, as shown in Fig. 1, having an outer circumference formed with a spline 3a and an inner circumference formed with a spline bore 3b that can be engaged with the second shaft 2. [0025] The clutch part 6 is made of a plurality of plate members to transmit and to interrupt selectively the power between the clutch housing 5 and the output rotary member 3. The clutch part 6 includes three first clutch plates 14 and four second clutch plates 15 having an annular shape and alternately stacked in the axial direction. The radially outer end of the first clutch plate 14 is formed with a plurality of engagement protrusions 14a extending outward and engaged with the spline of the clutch housing 5. The second clutch plate 15 has opposite surfaces to which friction facings are attached. A radially inner portion of the second clutch plate 15 is formed with a spline 15a. which is engaged with the spline 3a formed at the radially outer end of the output rotary member 3. The pressure plate 7 is an annular member that presses the plate members 14 and 15 of the clutch part 6 against each other, and is located on the outside of second clutch plate 15 farthest outward in the axial direction The pressure plate 7 is formed with a spline 7a at the radially outer end with the spline 7a being engaged with the outer spline of the first cylindrical portion 5b of the clutch housing 5. In addition, the pressure plate 7 has press protrusions 7b at an inner periphery on an axially outer surface thereof so that the protrusions 7b are annular and extend outward in the axial direction. [0027] The diaphragm spring 8 is a member which can be brought into contact with the pressure plate 7, and has, as shown in Fig. 1 and Fig. 2. a radially outer portion forming an annular plate 8a and a radially inner portion forming a lever part 8b made of a plurality of levers 8e radially inward of the annular plate 8a. [0028] The annular plate 8a has three projections (not illustrated) that project toward the clutch housing 5 radially outward so that the three projections are engaged with the inner circumference of the clutch housing 5. The inner circumference of the annular plate 8a is in contact with the annular press protrusions 7b of the pressure plate 7. and the outer circumference of the annular plate 8a is supported by a stopper ring 25 via a wire ring 20. The annular plate 8a has a radially inner portion that is closer to the pressure plate 7 than a radially outer portion thereof. The lever part 8b is made of a plurality of levers 8e. Each of the levers 8e has a support portion 8c that is located farthest inward in the radial direction and is supported by the release mechanism 4 later described and a connection portion 8d that connects the support portion 8c with the annular plate 8a. The radially inner end of the lever part 8b is located closer to the clutch part 6 than the radially outer end of the annular plate 8a. The support portion 8c is located closer to the clutch part 6 than contact points between the diaphragm spring 8 and the pressure plate 7, and is supported by the release mechanism 4 later described The connection portion 8d has a flat shape for connection between the annular plate 8a and the support portion 8c, and, as shown in Fig. 2, to which the centrifugal element 9 later described is attached [0030] When the motorcycle clutch device 1 is rotated, the annular plate 8a is pressed toward the clutch part 6 by centrifugal force that is applied to the centrifugal elements because the cento of gravity of a combination of the diaphragm spring 8 and the centrifugal elements 9 is located closer to the clutch part 6 than the annular plate 8a in the axial direction. [0031] The release mechanism 4 is a mechanism that releases the pressing load of the diaphragm spring 8 to the pressure plate 7. and includes a release member 4a. a release bearing 4br a first stop ring 4c. and a second stop ring 4d The release member 4a is a disc plate member having a cylindrical part 4f at the inner periphery. As shown in Fig. 2. a plurality of projections 4h protruding toward the clutch housing 5 is provided radially outward of the cylindrical part 4f. Between the adjacent two projections 4h is located the lever part 8b of the diaphragm spring 8. The release bearing 4b is attached to the inner circumference of the cylindrical part 4f. The first stop ring 4c is, as shown in Fig. 2. an annular member lacking one portion, and is located on a transmission side of the release bearing 4b. The second stop ring 4d is located on the outer circumference of the cylindrical part 4£ A plurality of protrusions 4e protruding outward in the axial direction is provided on a disc part 4g of the release member 4a; the protrusion 4e and the second stop ring 4d restrict the movement of the support portion 8c of the diaphragm spring 8 in the axial direction. [0032] The centrifugal element 9 is a metal plate member, and as shown in Fig. 25 is bent and wound around the lever part 8b of the diaphragm spring 8. The centrifugal elements 9 push the diaphragm spring 8 toward the pressure plate 7 according to the rotation of the diaphragm spring 8. In order to alter or adjust the pressure force to -the clutch part 6. the positions of the centrifugal elements 9 along the levers 8e are adjusted. More specifically, if it is desired that the pressure force be higher, the centrifugal elements 9 are moved radially outward. [0033] [Operation] A description will be made on the operation of the clutch. The power of the first shaft 31 connected to the engine is transmitted to the clutch housing 5 -\ia the drive gear 32 and the input gear 12. Since the projections at the radially outer portion of the annular plate 8a of the diaphragm spring 8 are engaged with the inner circumference of the clutch housing 5, the power of the clutch housing 5 is transmitted to the diaphragm spring 8 for rotation. At this time, the support portion 8c of the lever 8e is located closer to the clutch part 6 than the radially outer end of the annular plate 8a, and the connection portion 8d of the lever 8e has a flat shape to connect the annular plate 8a with the support portion 8c and to hold the centrifugal elements. As a result the centrifugal force elastically deforms the diaphragm spring 8 so that the annular plate 8a presses the pressure plate 7 toward the clutch part 6. Furthermore, since the centrifugal elements 9 are attached to the connection portions 8d of the diaphragm spring 8. the centrifugal force, being applied to the centrifugal elements 9, presses the diaphragm spring 8 further toward the clutch part 6. The pressure force causes the clutch part 6 to shift from a power interrupting stale to a power transmitting state. In this case, the power from the input gear 12 is transmitted to the clutch housing 5, the first clutch plates 14, and the second clutch plates 15 in this order, and further, from the second clutch plates 15 to the output rotary member 3. Finally, the power is transmitted from the output rotary member 3 to the second shaft 2. [0035] When the number of revolutions of the diaphragm spring 8 becomes lower, the centrifugal force applied to the diaphragm spring 8 becomes smaller. Consequently, the pressure forces of the centrifugal elements 9 and the diaphragm spring 8 to the pressure plate 7 become smaller, thus, the elastic deformation of the diaphragm spring 8 is released. In this operation, the pressure force of the pressure plate 7 to the clutch part 6 becomes smaller so that the clutch changes to a power interrupting state. When the clutch shifts from a power transmitting state to a power interrupting state, no other members are required. As a result, the number of parts in the clutch device becomes smaller, because the diaphragm spring 8 returns to the original state by its own elastic force. [0036] When shifting gears, it is necessary to force the clutch to change to a power interrupting state. In this operation, the release bearing 4b is shifted from a state shown in Fig. 1 outward in the axial direction. Then, via the release member 4a, the lever part 8b of the diaphragm spring 8 is moved outward in the axial direction. Accordingly, the radially inner portion of the annular plate 8a of the diaphragm spring 8 is moved outward in the axial direction, and the radially inner portion of the annular plate 8a moves away from the press protrusions 7b of the pressure plate 7. In this operation, when the pressure force of the pressure plate 7 to the clutch part 6 is released, the clutch part 6 changes to a power interrupting state. Then, after shifting gears, the clutch returns to a power transmitting state again. At this time, strange noises or impact during clutch engagement are unlikely to occur because the clutch device 1 is attached to the second shaft 2, the number of revolutions for which is relatively low. When the release force is released after the release mechanism 4 forces the clutch to be disengaged the diaphragm spring 8 returns to its original state by its own elastic force. As a result no return member is required and the number of parts can be reduced. [0037] [Other embodiments] In the above-described embodiment, the centrifugal elements 9 are attached to all of the lever parts 8b of the diaphragm spring 8- According to the present invention, however; the centrifugal elements may be attached to some of the levers, but not to all of the levers. Furthermore, although in the above-described embodiment, a pull-type clutch device is used, a push-type clutch can be used. In addition, although in the above-described embodiment a multi-plate clutch part is used, a single-plate clutch part can be used [Industrial applicability] [0038] According to the present invention, the impact at the clutch engagement can be reduced, and the pressure force to the clutch part for the clutch engagement can be obtained. [Title of Document] Claims paraiJei with a Jtirst shart coaxial with a crankshart of an engine, said device transmitting power to a transmission and being forced to interrupt power to the transmission by the operation of a release mechanism, comprising: a clutch housing being able to be rotatably supported by the second shaft and power being able to be input from said first shaft thereto; a disc-like rotary member being located within said clutch housing and being connectable to said second shaft; a clutch part selectively transmitting and interrupting the power between said clutch housing and said rotary member; a pressure plate being configured to press said clutch part; a lever plate being in contact with said pressure plate and having a plurality of levers; a centrifugal element being attached to said lever of said lever plate to press said lever plate toward said pressure plate by centrifugal force according to the rotation of said lever plate; and a release member releasing the pressure of said lever plate to said pressure plate, said lever plate is a diaphragm spring having a plate part at a radially outer portion thereof and a lever part being made of said levers extending radially inward from said plate part, said lever plate is configured such that a radially outer end of said plate part is supported by said clutch housing, and a radially inner end of said lever part is supported by said release member, and said radiallv inner end of said lever part is located closer to said clutch part than said radially outer portion of said plate part. 2. [amend] The motorcycle clutch device according to claim 1_, wherein said centrifugal element is attached to said lever in a position closer to said clutch part than said radially outer portion of said plate portion supported by said clutch housing. 5- [amendj The motorcycle clutch device according to claim 1 or 2, wherein said centrifugal element is a plate member that is wound around at least one of said levers of said lever plate. 4~ [amend] The motorcycle clutch device according to claim 2 or 3, wherein the pressing load to said clutch part is adjustable by changing a position where said centrifugal element is attached.

Documents:

807-CHENP-2008 AMENDED CLAIMS 21-02-2012.pdf

807-CHENP-2008 FORM-3 21-02-2012.pdf

807-CHENP-2008 OTHER PATENT DOCUMENT 21-02-2012.pdf

807-CHENP-2008 POWER OF ATTORNEY 21-02-2012.pdf

807-CHENP-2008 CORRESPONDENCE OTHERS 02-12-2011.pdf

807-CHENP-2008 CORRESPONDENCE PO.pdf

807-CHENP-2008 EXAMINATION REPORT REPLY RECEIVED 21-02-2012.pdf

807-CHENP-2008 FORM-3 18-08-2008.pdf

807-CHENP-2008 POWER OF ATTORNEY.pdf

807-chenp-2008-abstract.pdf

807-chenp-2008-claims.pdf

807-chenp-2008-correspondnece-others.pdf

807-chenp-2008-description(complete).pdf

807-chenp-2008-drawings.pdf

807-chenp-2008-form 1.pdf

807-chenp-2008-form 18.pdf

807-chenp-2008-form 3.pdf

807-chenp-2008-form 5.pdf

807-chenp-2008-pct.pdf