Clutch device

Abstract

Limits the transmission of excessive back torque. [Solution] The clutch device comprises a first rotating member, a second rotating member, a first friction plate, a second friction plate, and a plurality of friction materials. The second rotating member is arranged to rotate relative to the first rotating member. The first friction plate is configured to rotate integrally with the first rotating member. The second friction plate is configured to rotate integrally with the second rotating member. Each friction material is fixed to the first friction plate. Each friction material is arranged in the circumferential direction. Each friction material has a flat portion and an inclined portion. The flat portion is in contact with the second friction plate. The inclined portion is oriented axially and is inclined in the direction in which the first friction plate rotates relative to the second friction plate during deceleration.

Description

Technical Field

[0001] The present invention relates to a clutch device.

Background Art

[0002] Saddle-type vehicles such as motorcycles have a clutch device. The clutch device is configured to transmit power from a prime mover such as an internal combustion engine to a drive wheel or cut off the power transmission. Torque transmission is performed between a drive plate that rotates integrally with a clutch housing and a driven plate that rotates integrally with a clutch center (Patent Document 1).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] When shifting down to decelerate, excessive back torque may be transmitted from the drive wheel toward the prime mover, resulting in a decrease in vehicle body stability. For this reason, there is a desire to limit the transmission of excessive back torque. Therefore, an object of the present invention is to limit the transmission of excessive back torque.

Means for Solving the Problems

[0005] The clutch device according to the first embodiment is a clutch device for a saddle-type vehicle. This clutch device comprises a first rotating member, a second rotating member, a first friction plate, a second friction plate, and a plurality of friction materials. The second rotating member is arranged to rotate relative to the first rotating member. The first friction plate is configured to rotate integrally with the first rotating member. The second friction plate is configured to rotate integrally with the second rotating member. Each friction material is fixed to the first friction plate. Each friction material is arranged in the circumferential direction. Each friction material has a flat portion and an inclined portion. The flat portion is in contact with the second friction plate. The inclined portion is oriented axially and is inclined in the direction in which the first friction plate rotates relative to the second friction plate during deceleration.

[0006] When the clutch device receives back torque, the first friction plate rotates relative to the second friction plate, and the oil present between each friction material is guided between the flat surface and the second friction plate by the inclined surface. As a result, oil enters between each friction material and the second friction plate, causing slippage between the first and second friction plates. This limits the transmission of excessive back torque.

[0007] The clutch device according to the second embodiment is configured as follows in the clutch device according to the first embodiment. The inclined portion is further inclined to face radially inward. With this configuration, more oil can be supplied between each friction material and the second friction plate.

[0008] The clutch device according to the third embodiment is configured as follows in the clutch device according to the first or second embodiment: The circumferential dimension of the inclined surface decreases toward the radially outward direction.

[0009] The clutch device according to the fourth embodiment is configured as follows in the clutch device according to any of the first to third embodiments: The distance between adjacent pairs of friction materials increases radially outward.

[0010] The clutch device according to the fifth embodiment is configured as follows in the clutch device according to any of the first to fourth embodiments: The inclined portion has a lower surface roughness than the flat portion. This configuration makes it easier for oil to be delivered between the friction material and the second friction plate.

[0011] The clutch device according to the sixth embodiment is configured as follows in the clutch device according to any of the first to fifth embodiments: The friction material has a longer radial dimension than its circumferential dimension.

[0012] The clutch device according to the seventh embodiment further comprises a third rotating member in addition to the clutch device according to any of the first to sixth embodiments. The third rotating member has a pressing surface. The third rotating member is arranged to be axially movable relative to the second rotating member. The second rotating member has a pressure-receiving surface. The first friction plate and the second friction plate are arranged in the axial direction between the pressing surface and the pressure-receiving surface.

[0013] The clutch device according to the eighth embodiment is configured as follows in the clutch device according to the seventh embodiment: The third rotating member has a cylindrical portion. The cylindrical portion extends in the axial direction. The second rotating member has a columnar portion. The columnar portion extends in the axial direction within the cylindrical portion.

[0014] The clutch device according to the ninth embodiment further comprises a coil spring in addition to the clutch device according to the eighth embodiment. The coil spring biases the third rotating member such that the pressing surface faces the pressure receiving surface. The coil spring is arranged inside the cylindrical portion. The column portion extends inside the coil spring.

[0015] The clutch device according to the tenth embodiment further comprises a support plate in the clutch device according to the eighth embodiment. The support plate is attached to the column portion. The cylindrical portion has an inner flange portion that protrudes inward. The coil spring is positioned between the support plate and the inner flange portion. [Effects of the Invention]

[0016] According to the present invention, it is possible to limit the transmission of excessive back torque.

Brief Description of the Drawings

[0017] [Figure 1] Plan view of the clutch device. [Figure 2] Cross-sectional view taken along line II-II of FIG. 1. [Figure 3] Plan view of the drive plate. [Figure 4] Perspective view of the drive plate. [Figure 5] Cross-sectional view for showing the oil flow during deceleration. [Figure 6] Cross-sectional view for showing the oil flow during deceleration in a modified example. [Figure 7] Perspective view of the friction material in a modified example.

Embodiments for Carrying Out the Invention

[0018] Hereinafter, the clutch device 100 according to the present embodiment will be described with reference to the drawings. In the following description, the axial direction is the direction in which the rotation axis O of the clutch device 100 extends. The circumferential direction is the circumferential direction of a circle centered on the rotation axis O, and the radial direction is the radial direction of a circle centered on the rotation axis O. The forward rotation direction R1 is the direction in which the clutch device 100 rotates when the vehicle on which the clutch device 100 is mounted travels forward, and the reverse rotation direction R2 is the rotation direction opposite to the forward rotation direction R1.

[0019] [Clutch Device] FIG. 1 is a plan view of the clutch device 100, and FIG. 2 is a cross-sectional view taken along line II-II of FIG. 1. As shown in FIGS. 1 and 2, the clutch device 100 is configured to transmit the power from a prime mover (for example, a prime mover) to a drive wheel or to cut off the transmission. The clutch device 100 is configured to transmit power in the forward rotation direction R1 (counterclockwise in FIG. 1). The clutch device 100 is configured to be rotatable. Specifically, the clutch device 100 rotates in the forward rotation direction R1 about the rotation axis O.

[0020] The clutch device 100 has a clutch housing 2 (an example of a first rotating member), a clutch center 3 (an example of a second rotating member), a pressure plate 4 (an example of a third rotating member), a plurality of drive plates 5 (an example of a first friction plate), a plurality of driven plates 6 (an example of a second friction plate), and a friction material 7.

[0021] Also, the clutch device 100 has a plurality of support plates 8, a plurality of bolts 9, and a plurality of coil springs 11. Note that the clutch device 100 does not have a cam mechanism. Specifically, when the clutch center 3 and the pressure plate 4 rotate relative to each other during acceleration or deceleration, it does not have a cam mechanism configured to convert the force in the relative rotation direction into a force that causes the pressure plate 4 to move in the axial direction. Note that the clutch device 100 may have a cam mechanism.

[0022] [Clutch housing] The clutch housing 2 is arranged to be rotatable about the rotation axis O. The clutch housing 2 has a disk portion 21 and a cylindrical portion 22. The clutch housing 2 is connected to the input gear 10. This input gear 10 is an annular member to which the power generated by the prime mover is input. The input gear 10 meshes with a drive gear (not shown) fixed to the crankshaft on the prime mover side.

[0023] The disk portion 21 is connected to the input gear 10 via a plurality of coil springs (not shown). The cylindrical portion 22 extends from the outer peripheral edge portion of the disk portion 21 to the first side in the axial direction. The cylindrical portion 22 has a plurality of notches 221 extending in the axial direction. The plurality of notches 221 are arranged at intervals in the circumferential direction.

[0024] [Clutch center] The clutch center 3 is rotatably positioned around the rotation axis O. The clutch center 3 is rotatably positioned relative to the clutch housing 2. The clutch center 3 is positioned on the first axial side relative to the clutch housing 2. Furthermore, the clutch center 3 is positioned radially inward relative to the cylindrical portion 22 of the clutch housing 2. That is, the clutch center 3 is positioned so as to be surrounded by the clutch housing 2. The clutch center 3 is positioned so as to be immovable in the axial direction.

[0025] The clutch center 3 has a boss portion 31, a first base portion 32, a plurality of column portions 33, a plurality of ribs 34, a first cylindrical portion 35, a flange portion 36, and a pressure-receiving surface 37.

[0026] The boss portion 31 extends in the axial direction. The boss portion 31 is cylindrical. The boss portion 31 has a spline hole 31a in its central part that extends in the axial direction. An input shaft (not shown) such as a transmission is spline-engaged into the spline hole 31a. In the axial direction, a thrust plate 14 is provided between the boss portion 31 and the input gear 10.

[0027] The first base portion 32 extends radially outward from the outer circumferential surface of the boss portion 31. The first base portion 32 is also annular in shape and extends circumferentially. The first base portion 32 is positioned radially outward relative to the boss portion 31. The first base portion 32 is connected to the first cylindrical portion 35.

[0028] The column portion 33 extends from the first base portion 32 in the first axial direction. The column portion 33 is cylindrical. The column portion 33 has a screw hole 331 that penetrates through it in the axial direction.

[0029] The ribs 34 are formed on the first base portion 32. The ribs 34 extend radially. The ribs 34 connect the boss portion 31 and the first cylindrical portion 35. The ribs 34 are inclined to become higher towards the radially outward direction. Each rib 34 is arranged alternately with each column portion 33 in the circumferential direction.

[0030] The first cylindrical portion 35 extends in the axial direction. The first cylindrical portion 35 has a plurality of external teeth 351. Each external tooth 351 is formed on the outer circumferential surface of the first cylindrical portion 35. Each external tooth 351 extends in the axial direction. Each external tooth 351 is spaced apart from one another in the circumferential direction.

[0031] The first cylindrical portion 35 has at least one through hole (not shown). The through hole penetrates the first cylindrical portion 35 radially. The through hole extends axially. Through this through hole, oil supplied to the radially inward side of the first cylindrical portion 35 is supplied to the drive plate 5 and driven plate 6, which are located radially outward from the first cylindrical portion 35.

[0032] The flange portion 36 extends radially outward from the first cylindrical portion 35. More specifically, the flange portion 36 extends radially outward from the second axial end of the first cylindrical portion 35. The surface of the flange portion 36 facing the first axial side becomes the pressure-receiving surface 37. That is, the pressure-receiving surface 37 faces the first axial side. The pressure-receiving surface 37 is an annular shape extending in the circumferential direction. The pressure-receiving surface 37 is located on the outer circumference of the clutch center 3.

[0033] [Pressure Plate] The pressure plate 4 is positioned to be movable in the axial direction. That is, the pressure plate 4 is axially relative to the clutch center 3. The pressure plate 4 is positioned to be rotatable about the rotation axis O. The pressure plate 4 is positioned in the axial direction between the clutch center 3 and the support plate 8.

[0034] The pressure plate 4 has a second base portion 41, a plurality of second cylindrical portions 42 (an example of a cylindrical portion), a plurality of connecting portions 43, a second flange portion 44, and a pressing surface 45.

[0035] The second base portion 41 is disc-shaped and has an opening in its center. A release mechanism (not shown) is configured to be attached to the opening of the second base portion 41.

[0036] The second cylindrical portion 42 extends from the second base portion 41 in the second axial direction. That is, the second cylindrical portion 42 extends from the second base portion 41 toward the first base portion 32 of the clutch center 3. The column portion 33 extends within the second cylindrical portion 42.

[0037] The second cylindrical portion 42 has an inner flange portion 421 that protrudes inward at its tip. The inner flange portion 421 is annular in shape. The inner flange portion 421 is configured to support the coil spring 11.

[0038] The connecting portion 43 protrudes from the second base portion 41 in the second axial direction. The connecting portion 43 extends in the circumferential direction so as to connect a pair of adjacent second cylindrical portions 42.

[0039] The second flange portion 44 is positioned radially outward relative to the second base portion 41. The surface of the second flange portion 44 facing the second axial side becomes the pressing surface 45. That is, the pressing surface 45 faces the second axial side. The pressing surface 45 is an annular shape extending in the circumferential direction. The pressing surface 45 is located on the outer circumference of the pressure plate 4.

[0040] The pressing surface 45 is positioned on the first axial side relative to the pressure-receiving surface 37. In an axial view, the pressing surface 45 overlaps with the pressure-receiving surface 37.

[0041] [Drive plate and driven plate] The drive plate 5 and the driven plate 6 are positioned between the pressure-receiving surface 37 and the pressing surface 45. The drive plate 5 and the driven plate 6 are arranged alternately in the axial direction. The drive plate 5 and the driven plate 6 are annular in shape and extend in the circumferential direction.

[0042] The drive plate 5 has a first surface 51 and a second surface 52. The first surface 51 is the surface facing the first side in the axial direction. The second surface 52 is the surface facing the second side in the axial direction.

[0043] Figure 3 is a plan view of the drive plate 5, and Figure 4 is a perspective view of the drive plate 5. As shown in Figures 2 to 4, the drive plate 5 is axially movable relative to the clutch housing 2 but not rotatable relative to it. The drive plate 5 rotates integrally with the clutch housing 2. In detail, the drive plate 5 has a plurality of engaging projections 53 that project radially outward. These engaging projections 53 engage with notches 221 formed in the cylindrical portion 22 of the clutch housing 2.

[0044] The driven plate 6 has multiple internal teeth (not shown). Each internal tooth meshes with each external tooth 351. As a result, the driven plate 6 is axially movable relative to the first cylindrical portion 35, but not rotatable relative to it. The driven plate 6 rotates integrally with the clutch center 3.

[0045] [Friction material] Figure 5 is a cross-sectional view showing the oil flow during deceleration. As shown in Figures 3 to 5, the friction material 7 is fixed to the drive plate 5. More specifically, the friction material 7 is bonded to the drive plate 5. On the first surface 51 of the drive plate 5, each friction material 7 is spaced apart from each other in the circumferential direction. Similarly, on the second surface 52 of the drive plate 5, each friction material 7 is spaced apart from each other in the circumferential direction. The circumferential positions of the friction material 7 on the first surface 51 of the drive plate 5 and the friction material 7 on the second surface 52 of the drive plate 5 are the same. That is, in an axial view, the friction material 7 on the first surface 51 of the drive plate 5 and the friction material 7 on the second surface 52 of the drive plate 5 overlap each other.

[0046] Each friction material 7 is formed from, for example, paper or cork.

[0047] The friction material 7 is rectangular in shape when viewed axially. The radial dimension of the friction material 7 is larger than the circumferential dimension. The distance between adjacent pairs of friction material 7 gradually widens towards the radial outward direction.

[0048] The friction material 7 has a flat portion 71 and an inclined portion 72. In the friction material 7 positioned on the first surface 51 of the drive plate 5, the flat portion 71 extends substantially parallel to the first surface 51 of the drive plate 5. In the friction material 7 positioned on the second surface 52 of the drive plate 5, the flat portion 71 extends substantially parallel to the second surface 52 of the drive plate 5. The flat portion 71 is in contact with the driven plate 6. In other words, the friction material 7 transmits torque via the flat portion 71.

[0049] The inclined portion 72 is inclined with respect to the flat portion 71. In the friction material 7 placed on the first surface 51 of the drive plate 5, the inclined portion 72 is inclined with respect to the first surface 51. Also, in the friction material 7 placed on the second surface 52 of the drive plate 5, the inclined portion 72 is inclined with respect to the second surface 52.

[0050] The inclined portion 72 is oriented axially and inclined to face the counter-rotation direction R2. That is, the inclined portion 72 is inclined to face the direction in which the drive plate 5 rotates relative to the driven plate 6 during deceleration. The inclined portion 72 extends from the flat portion 71 toward the first surface 51 or the second surface 52.

[0051] The surface roughness of the inclined portion 72 can be less than that of the flat portion 71. Here, surface roughness refers to the arithmetic mean roughness Ra. The surface roughness of the inclined portion 72 may be the same as that of the flat portion 71, or it may be greater than that of the flat portion 71.

[0052] Furthermore, of the sides of the friction material 7, the side 73 that faces in the opposite direction to the direction in which the inclined surface 72 faces in the circumferential direction, i.e., the side 73 that faces the positive rotation direction R1, extends perpendicularly to the first surface 51 or the second surface 52.

[0053] [Support plate] As shown in Figures 1 and 2, each support plate 8 is arranged in the circumferential direction. The support plates 8 are positioned on the first axial side relative to the clutch center 3. The support plates 8 are attached to the tip of the column portion 33 (upper end in Figure 2). In detail, bolts 9 fasten the clutch center 3 and the support plates 8 together. As a result, the support plates 8 rotate integrally with the clutch center 3.

[0054] [Coil spring] The coil spring 11 is positioned in the same location as the column portion 33 in the circumferential direction. More specifically, the column portion 33 extends within the coil spring 11. The coil spring 11 is located within the second cylindrical portion 42. In a compressed state, the coil spring 11 is located between the support plate 8 and the inner flange portion 421.

[0055] The coil spring 11 biases the pressure plate 4 to the second axial direction. As a result, the pressing surface 45 is biased to move closer to the pressure receiving surface 37, the clutch device 100 enters the clutch-on state, and power is transmitted. The release member moves the pressure plate 4 to the first axial direction against the biasing force of the coil spring 11, causing the pressing surface 45 to move away from the pressure receiving surface 37. As a result, the clutch device 100 enters the clutch-off state, and the transmission of power between the clutch housing 2 and the clutch center 3 is interrupted.

[0056] [Operation] As shown in Figure 5, during deceleration, especially when downshifting, the driven plate 6, which receives torque from the drive wheels, rotates relative to the drive plate 5 in the forward rotation direction R1. That is, a torque (so-called back torque) that attempts to cause the drive plate 5 to rotate relative to the driven plate 6 in the reverse rotation direction R2 is entered into the clutch device 100. As a result, the oil present between the pair of friction materials 7 is guided by the inclined surface 72, as indicated by the arrow in Figure 5, and flows towards the space between the flat surface 71 and the driven plate 6. Consequently, slippage occurs between the drive plate 5 and the driven plate 6, and the transmission of back torque input from the drive wheels can be limited.

[0057] [Differentiation] Although embodiments of the present invention have been described above, the present invention is not limited thereto, and various modifications are possible without departing from the spirit of the invention. Furthermore, the following modifications can basically be applied simultaneously.

[0058] (a) In the above embodiment, the friction material 7 was fixed to the drive plate 5, but the friction material 7 may be fixed to the driven plate 6 as shown in Figure 6. In this case, the drive plate 5 corresponds to the second friction plate of the present invention, and the driven plate 6 corresponds to the first friction plate of the present invention. Also, the clutch housing 2 corresponds to the second rotating member of the present invention, and the clutch center 3 corresponds to the first rotating member of the present invention.

[0059] In this case, the inclined portion 72 of the friction material 7 is oriented axially and inclined to face the positive rotation direction R1. That is, the inclined portion 72 is inclined to face the direction in which the driven plate 6 rotates relative to the drive plate 5 during deceleration.

[0060] (b) As shown in Figure 7, the inclined portion 72 of the friction material 7 may be inclined to face axially, in the opposite rotation direction R2, and also radially inward. The inclined portion 72 may also be configured such that its circumferential dimension decreases towards the radially outward direction. [Explanation of Symbols]

[0061] 2: Clutch housing 3: Clutch Center 33:Column part 4: Pressure plate 42: Second cylindrical section 5: Drive Plate 6: Driven Plate 7:Friction material 71: Flat part 72: Sloping section 100: Clutch device

Claims

1. A clutch device for saddle-type vehicles, First rotating member and A second rotating member is arranged to be rotatable relative to the first rotating member, A first friction plate configured to rotate integrally with the first rotating member, A second friction plate configured to rotate integrally with the second rotating member, Multiple friction materials fixed to the first friction plate and arranged in the circumferential direction, Equipped with, Each of the aforementioned friction materials has a flat portion that contacts the second friction plate, and an inclined portion that faces axially and is inclined in the direction in which the first friction plate rotates relative to the second friction plate during deceleration. Clutch device.

2. The aforementioned inclined portion is further inclined to face radially inward. The clutch device according to claim 1.

3. The aforementioned inclined portion has a circumferential dimension that decreases towards the radially outward direction. The clutch device according to claim 1.

4. The distance between adjacent pairs of friction materials increases radially outward. The clutch device according to claim 1.

5. The aforementioned inclined portion has a lower surface roughness than the aforementioned flat portion. The clutch device according to claim 1.

6. The friction material has a longer radial dimension than its circumferential dimension. The clutch device according to claim 1.

7. The system further comprises a third rotating member having a pressing surface and being arranged to be axially movable relative to the second rotating member, The second rotating member has a pressure-receiving surface, The first friction plate and the second friction plate are arranged in the axial direction between the pressing surface and the pressure receiving surface. The clutch device according to claim 1.

8. The third rotating member has a cylindrical portion extending in the axial direction, The second rotating member has a columnar portion that extends axially within the cylindrical portion. The clutch device according to claim 7.

9. The third rotating member is further provided with a coil spring that biases the pressing surface toward the pressure-receiving surface, The coil spring is arranged within the cylindrical portion. The column portion extends within the coil spring, The clutch device according to claim 8.

10. The column portion is further equipped with a support plate, The cylindrical portion has an inner flange portion that protrudes inward. The coil spring is positioned between the support plate and the inner flange portion. The clutch device according to claim 9.

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