Title of Invention

CENTRIFUGAL CLUTCH DEVICE

Abstract

A centrifugal clutch device 1 selectively transmits and interrupts power from an input shaft 2 to an output shaft 75. The device 1 includes a clutch housing 6 connected to the output shaft 75, a clutch carrier 4 connected to the input shaft 2, a centrifugal clutch part 5, and a hysteresis generation mechanism 7. The centrifiigal clutch part 5 is located at a radially outer portion of the clutch carrier 4 so that the centrifiigal clutch part 5 can move. The centrifugal clutch part 5 moves radially outward to contact an inner circumference of the clutch housing 6. The hysteresis generation mechanism 7 generates hysteresis as the centrifiigal clutch part 5 moves toward the clutch housing 6. The hysteresis generation mechanism 7 includes a support member 20 that supports the centrifugal clutch part 5 on the clutch carrier 4 so that the centrifugal clutch part 5 can move, a fiiction member 24 that applies resistance to the centrifugal clutch part 5 when the centrifiigal clutch part 5 moves, and a pressing mechanism that presses the friction member 24 and the centrifiigal clutch part 5 against each other.

Full Text

Specification Centrifugal Clutch Device [Technical field] (0001) The present invention relates to a centrifugal clutch device. The present invention particularly relates to a centrifugal clutch device that is installed onto a driving shaft to which power is input from an engine to transmit and to interrupt selectively power from the driving shaft to a transmission. [Background art] (0002) A centrifugal clutch device includes a clutch carrier connected to an input shaft, and a clutch housing connected to an output shaft, and a centrifugal clutch part (refer to Patent Document 1). In the centrifugal clutch device, power of the input shaft is transmitted via the clutch carrier to the centrifugal clutch part. When the power is transmitted to the centrifugal clutch part, a centrifugal force is applied to the centrifugal clutch part to move the part radially outward. When the centrifugal clutch part is moved, the centrifugal clutch part frictionally engages with the clutch housing so that the power of the centrifugal clutch part is transmitted to the clutch housing and then to a transmission-side member. Patent Document 1 Unexamined Patent Publication H6-280901 [Disclosure of Invention] In the centrifugal clutch device, when the centrifugal force is applied to the centrifugal clutch part to engage frictionally with the clutch housing, unwanted noise or impact might be produced due to sudden clutch engagement. (0004) It is an object of the present invention to reduce unwanted noises or impact when the clutch is engaged. (0005) According to a first aspect of the present invention, a centrifugal clutch device selectively transmits and mterrupts power from an input shaft to an output shaft, and includes a clutch carrier, a clutch housing, a centrifugal clutch part, and a hysteresis generation mechanism. The clutch carrier is connectable to the input shaft. The clutch housing is connectable to the output shaft. The centrifugal clutch part is located at a radially outer potion of the clutch carrier so that the centrifugal clutch part can move. The centrifugal clutch part moves radially outward to contact an inner circumference of the clutch housing. The hysteresis torque generation mechanism generates hysteresis as the centrifugal clutch part moves toward the clutch housing. The hysteresis generation mechanism includes a support member that supports the centrifugal clutch part on the clutch carrier so that the centrifugal clutch part can move, a friction member that applies resistance to the centrifugal clutch part when the centrifugal clutch part moves, and a pressing mechanism that i presses the friction member and the centrifugal clutch part against each other. (0006) In this centrifugal clutch device, the pressing mechanism presses the centrifugal clutch part and the friction member against each other, and when power is transmitted from the input shaft to the centrifugal clutch part, the centrifugal clutch part is brought into contact with the inner circumference surface wall of the clutch housing. As a result, power is transmitted between the centrifugal clutch part and the clutch housing. In summary, the power is transmitted from the input shaft to the centrifugal clutch device, and when the centrifugal clutch part moves radially outward, the hysteresis is generated between the friction member and the centrifugal clutch part. (0007) Since the hysteresis is generated when the clutch is engaged, the centrifugal clutch part receives resistance when it moves radially outward, thereby preventing the clutch from being engaged suddenly. As a result, unwanted noise or impact is reduced when the clutch is engaged. (0008) A centrifugal clutch device according to a second aspect of the present invention is the device accordmg to the first aspect, wherein the clutch housing has a cylindrical portion that encompasses the centrifugal clutch part. The centrifugal clutch part includes a plurality of clutch weights each having one end rotatably supported on the clutch carrier via the support member, clutch shoes provided on radially outer sides of the clutch weights to be pressed against the inner circumference wall of the cylmdrical portion of the clutch housing when the clutch weights rotate, and urging members that urge the other ends of the clutch weights radially inward. (0009) In the centrifugal clutch device, when the power is transmitted to the clutch carrier, the clutch weights rotate around the ends supported by the clutch carrier, and the clutch shoes provided on the clutch weights are brought into contact with the clutch housing, resulting in a power-transmitting state. (0010) A centrifugal clutch device according to a third aspect of the present invention is the device according to the second aspect, wherein the support member has columns that support the clutch weights, and disc portions that are located between the clutch weights and the clutch carrier. The friction member includes members that are located between the clutch weights and the disc portions. (0011) A centrifugal clutch device according to a fourth aspect of the present invention is the device according to the third aspect, wherein the pressing mechanism includes wave springs that are located at the columns of the support member to press the clutch weights toward the members of the friction member. [Brief description of drawings] (0012) Fig. 1 is a cross sectional view in an embodiment of the present invention. Fig. 2 is a plain view of a centrifugal clutch device in the present invention. [Explanations of letters or numerals] (0013) 1 centrifugal clutch device 3 clutch hub 4 clutch carrier 5 centrifugal clutch part 6 clutch housing 7 hysteresis generation mechanism 10 supply path 20 support member 30 clutch weight 31 clutch shoe 35 coil spring [Best mode for carrying out the invention] (0014) [Structure] Fig. 1 is a sectional view of a centrifugal clutch device 1 according to one embodiment of the present invention. The centrifugal clutch device 1 in this embodiment is a device installed onto an input shaft 2 that can be connected to the engine, and selectively transmits and interrupts power from the input shaft 2 to an output shaft 75. The centrifugal clutch device 1 includes a clutch boss 3, a clutch carrier 4, a centrifiigal clutch part 5, a clutch housing 6, and a hysteresis generation mechanism 7. hereinafter, the right side in Fig. 1 will be referred to as an axially outer side, and the left side in Fig. 1 will be referred to as an axially inner side. (0015) The clutch boss 3 is an annular member that has an inner circumference formed with a spline 11, which can be engaged with a spline formed on an outer circumference of the input shaft 2. Second lubricant supply paths 10 that penetrate from the inner circumference to the outer circumference are formed on a side surface of the clutch boss 3 near the clutch carrier 4. Each second lubricant supply path 10 is a path that supplies the lubricant through a first lubricant supply path 9 formed in the input shaft 2 to the centrifiigal clutch part 5. The path 10 is formed by forging or machining so that it has a groove shape formed in a straight line from the input shaft 2 to the centrifugal clutch part 5. (0016) The clutch carrier 4 is a plate member, and is located so that its radially inner portion is in contact with the axially outer end surface of the clutch boss 3. The clutch carrier 4 includes a first disc portion 14 that is in contact with the end surface of the clutch boss 3, a cylindrical portion 13 formed around the outer periphery of the first disc portion 14, and a second disc portion 15 located around the outer periphery of the cylindrical portion 13 and axially outside the first disc portion 14. The first disc portion 14 has an inner circumference formed with a spline with which the input shaft 2 is to be engaged. (0017) The centrifugal clutch part 5 is as shown in Fig. 1 and Fig. 2, located radially outward of the clutch boss 3, and includes three arcuate clutch weights 30, clutch shoes 31 fixed to radially outer surfaces of the respective clutch weights 30, support members 20 to support one end of each of the clutch weights 30, and coil springs 35 to connect adjacent two clutch weights 30 with each other. (0018) The clutch weight 30 has one circumferential end that is rotatably supported on the clutch carrier 4 via the support member 20. When the clutch weight 30 rotates around the support member 20, the other end moves radially outward so that the clutch shoes 31 make contact with an inner circumference wall surface of the clutch housing 6. (0019) The clutch shoe 31 is a portion that is pressed against the inner circumference of the clutch housing 6 when the other circumferential end of the clutch weight 30 rotates around the support member 20. The clutch shoe 31 has a radially outer surface formed with a plurality of second grooves 34 extending in the circumferential direction. (0020) Each of the three support members 20 is located at a radially outer portion of the clutch carrier 4, and has a caulking portion 21, a plate portion 22, and a column 23. The caulking portion 21 is obtained by caulking an axially outer end of the support member 20 in order to fix the support member 20 to the clutch carrier 4. The plate portion 22 is a disc member that is larger than the caulking portion 21 in thickness, and is located to make contact with a side surface of an axially inner end of the second disc portion 15. The column 23 is a cylindrical member that supports the one end of the clutch weight 30. (0021) The coil spring 35 is provided to connect the adjacent two clutch weights 30 with each other, and to urge the clutch weights 30 radially inward. The coil spring 35 has one end that is engaged with a base end (an end supported by the support member 20) of one of the adjacent two clutch weights 30, and the other end that is engaged with a tip of the other of the two clutch weights 30. This structure allows the clutch weights 30 to be urged inward in the radial direction by the coil springs 35 and the clutch shoes 31 to be separated from the clutch housing when the centrifugal force is not applied to the clutch weights 30. (0022) The clutch housing 6 is a member that is fixed to the output shaft 75 and has an inner circumference against which the centrifugal clutch part 5 is pressed. The clutch housing 6 includes a disc portion 40 and a cylindrical portion 41. The disc portion 40 has a radially inner portion that is fixed to the output shaft 75. The cylindrical portion 41 extends outward in the axial direction from the outer periphery of the disc portion 40 to a position approximately corresponding to the clutch carrier 4. Inside of the cylindrical portion 41 is located the centrifugal clutch part 5. At an interface between the disc portion 40 and the cylindrical portion 41 are formed four holes 42 at equal angular intervals in the circumferential direction. The purpose of the holes 42 is to exhaust the lubricant, which is supplied from the second lubricant supply path 10 to the centrifugal clutch part, out of the clutch housing 6. (0023) The hysteresis generation mechanism 7 includes friction members 24 attached to axially outer ends of the clutch weights 30 and axially inner ends of the plate parts 22, wave springs 25 located at axially inner ends of the clutch weights 30, and stopper plates 60 located axially inward of the wave springs 25. The friction member 24 is an annular member sandwiched between the clutch weight 30 and the plate portion 22 of the support member 20 to generate hysteresis torque. The wave spring 25 is an annular plate member that is deformed like a wave to urge the clutch weight 30 toward the friction member 24. The wave spring 25 is located at the axially inner end of the clutch weight 30 so that it is flatly deformed. The stopper plate 60 is an annular plate member that has an inner circumference formed with a plurality of projections 61 projecting radially inward, which engage with grooves 65 of the support member 20. (0024) [Operation] The power from the engine is transmitted through the clutch carrier 4, the support member 20, and the centrifugal clutch part 5 in this order. When the power is transmitted to the centrifugal clutch part 5, the clutch weights 30 rotate together with the clutch carrier 4. At this time, the centrifugal force is applied to the clutch weights 30 to move the clutch weights 30 radially outward. Since one end of the clutch weight 30 is supported by the support member 20, the other end rotates around the support member 20. This rotation causes the clutch shoes 31 of the centrifugal clutch part 5 to engage frictionally with the inner circumference of the clutch housing 6. As a result, the power is transmitted from the centrifugal clutch part 5 to the clutch housing 6. Then, the power is transmitted from the clutch housing 6 to the output shaft 75. (0025) hi the above-mentioned operation, when the clutch weight 30 rotates aroimd the support member 20, hysteresis is generated between the friction member 24 attached to the support member 20 and the clutch weight 30, or between the friction member 24 and the plate part 22 of the support member 20. Since the hysteresis generation mechanism 7 generates the hysteresis, the clutch weights 30 encounter resistance during the rotation so that the clutch is engaged smoothly. As a result, unwanted noise or impact is unlikely to occur when the clutch is engaged. (0026) On the other hand, when the rotational speed of the centrifugal clutch part 5 decreases, the centrifugal force applied to the clutch weight 30 becomes smaller than the urging force by the coil spring 35. In this case, the frictional engagement between the clutch housing 6 and the centrifugal clutch part 5 is released, so that the power of the centrifugal clutch part 5 is not transmitted to the clutch housing 6, that is, in a power-interrupting state. (0027) [Other embodiments] Although in one embodiment of the present invention each of the three clutch weights 30 is composed of one member respectively, the clutch weight can be composed of a lamination of a plurality of plate members to work in the present invention. [Industrial Applicability] (0028) In the present invention, it is possible to reduce unwanted noise or impact that might be generated when the clutch is engaged by applying the hysteresis to the centrifugal clutch part. [Title of Document] Claims 1. A centrifugal clutch device for selectively transmitting and interrupting power from an input shaft to an output shaft, comprising: a clutch carrier being connectable to said input shaft; a clutch housing being connectable to said output shaft; a centrifugal clutch part being located at a radially outer portion of said clutch carrier to be movable, said centrifiigal clutch part moving radially outward to contact an inner circumference of said clutch housing; and a hysteresis generation mechanism generating hysteresis as said centrifiigal clutch part moves toward said clutch housing, said hysteresis generation mechanism including a support member supporting said centrifiigal clutch part on said clutch carrier so that said centrifiigal clutch part is movable, a friction member applying resistance to said centrifugal clutch part when said centrifiigal clutch part moves, and a pressing mechanism pressing said fiiction member and said centrifiigal clutch part against each other. 2. The centrifiigal clutch device according to claim 1, wherein said clutch housing has a cylindrical portion that encompasses said centrifugal clutch part, said centrifugal clutch part includes a plurality of clutch weights each having one end being rotatably supported on said clutch carrier via said support member, clutch shoes provided on radially outer portions of said clutch weights for being pressed against said inner circumference of said cylindrical portion of said clutch housing when said clutch weights rotate, and urging members urging the other ends of said clutch weights radially inward. 3. The centrifugal clutch device according to claim 2, wherein said support member has columns that support said clutch weights, and disc portions that are located between said clutch weights and said clutch carrier, said friction member includes members that are located between said clutch weights and said disc portions. 4. The centrifugal clutch device according to claim 3, wherein said pressing mechanism includes wave springs that are located at said columns of said support member to press said clutch weights toward said members of said friction member.

Documents:

853-CHENP-2008 EXAMINATION REPORT REPLY RECEIVED 17-10-2012.pdf

853-CHENP-2008 CORRESPONDENCE OTHERS 27-02-2014.pdf

853-CHENP-2008 CORRESPONDENCE OTHERS. 23-11-2012.pdf

853-CHENP-2008 AMENDED CLAIMS 26-12-2012.pdf

853-CHENP-2008 CORRESPONDENCE OTHERS 20-02-2014.pdf

853-CHENP-2008 EXAMINATION REPORT REPLY RECEIVED 26-12-2012.pdf

853-CHENP-2008 FORM-3 26-12-2012.pdf

853-CHENP-2008 POWER OF ATTORNEY 26-12-2012.pdf

853-chenp-2008-abstract.pdf

853-chenp-2008-claims.pdf

853-chenp-2008-correspondnece-others.pdf

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

853-chenp-2008-drawings.pdf

853-chenp-2008-form 1.pdf

853-chenp-2008-form 18.pdf

853-chenp-2008-form 3.pdf

853-chenp-2008-form 5.pdf

853-chenp-2008-pct.pdf