JP7598990B1 - Centrifugal clutch and vehicle - Google Patents

Abstract

A technology is provided that can suppress abnormal noise from a centrifugal clutch using an anti-vibration ring with a simpler configuration.
[Solution] A centrifugal clutch comprises a clutch inner connected to an input shaft to which power is transmitted and rotating integrally with the input shaft, a clutch outer connected to an output shaft and rotating integrally with the output shaft, a clutch shoe supported by the clutch inner and moving by centrifugal force generated by the rotation of the clutch inner to frictionally engage with the inner surface of the clutch outer, and a vibration-damping ring provided on the outside of the clutch outer, wherein the vibration-damping ring has a first contact portion that contacts the outer surface of the clutch outer and a second contact portion that contacts the outer surface with a smaller contact area than the first contact portion, and when a first region is defined as an area of the outer surface of the clutch outer that is within ±90 degrees of the contact center of the first contact portion in the circumferential direction, and a second region is defined as an area other than the first region, the second contact portion contacts the second region.
[Selected Figure] Figure 4

Description

The present invention relates to a centrifugal clutch and a vehicle.

In centrifugal clutches mounted on motorcycles and the like, when the clutch shoe (friction member) comes into contact with the inner surface of the clutch outer and slips due to the centrifugal force generated by the rotation of the clutch inner, the clutch outer vibrates and may produce abnormal noise (also called squealing). Patent Document 1 discloses that abnormal noise from a centrifugal clutch can be suppressed by providing an anti-vibration ring (anti-vibration cover) on the outside of the clutch outer, in which the line contact parts and surface contact parts that come into contact with the outer surface of the clutch outer are evenly arranged in the circumferential direction.

JP 2006-71096 A

From the standpoint of productivity and processability, there is a demand for centrifugal clutches to suppress abnormal noise (squeak) using anti-vibration rings with a simpler (easier) structure.

The present invention aims to provide a technology that can suppress abnormal noise from centrifugal clutches using a vibration-damping ring with a simpler configuration.

In order to achieve the above object, a centrifugal clutch according to one aspect of the present invention comprises a clutch inner coupled to an input shaft to which power is transmitted and rotates integrally with the input shaft, a clutch outer coupled to an output shaft and rotates integrally with the output shaft, a clutch shoe supported by the clutch inner and moving by centrifugal force due to the rotation of the clutch inner to frictionally engage with the inner surface of the clutch outer, and a vibration-proof ring provided on the outside of the clutch outer, the vibration-proof ring having a first contact portion that contacts the outer surface of the clutch outer and a second contact portion that contacts the outer surface with a contact area smaller than that of the first contact portion, and configured not to contact the outer surface at any portion other than the first contact portion and the second contact portion, and characterized in that when a region of the outer surface of the clutch outer that is within ±90 degrees of the contact center of the first contact portion in the circumferential direction is defined as a first region, and a region other than the first region is defined as a second region, the second contact portion is disposed on the vibration-proof ring so as to contact the second region.

The present invention provides a technology that can suppress abnormal noise from a centrifugal clutch, for example, by using a vibration-damping ring with a simpler configuration.

Left side view of saddle-type vehicle Diagram showing the internal structure of the power unit A diagram showing the configuration of the driven pulley, centrifugal clutch, and surrounding areas. FIG. 1 is a diagram showing a first example of a configuration of an anti-vibration ring according to an embodiment of the present invention; FIG. 13 is a diagram showing a second configuration example of an anti-vibration ring according to an embodiment of the present invention; FIG. 13 is a diagram showing a third example of the configuration of an anti-vibration ring according to an embodiment of the present invention. FIG. 4 is a diagram showing a fourth configuration example of an anti-vibration ring according to an embodiment of the present invention. FIG. 5 is a diagram showing a configuration example 5 of an anti-vibration ring according to an embodiment of the present invention. FIG. 1 is a diagram showing the effect of an anti-vibration ring according to an embodiment of the present invention.

The following describes an embodiment of the present invention with reference to the drawings. The present invention is not limited to the following embodiment, and includes configuration changes and modifications within the scope of the present invention. Furthermore, not all of the combinations of features described in the present embodiment are necessarily essential to the present invention. Note that identical components are given the same reference numbers and their description will be omitted.

Figure 1 shows a left side view of a saddle-ride type vehicle 1 equipped with a centrifugal clutch according to one embodiment of the present invention. In Figure 1, arrow FR indicates the front of the saddle-ride type vehicle 1, arrow LH indicates the left side of the vehicle, and arrow UP indicates the upper side of the vehicle. Below, a unit swing type motorcycle will be described as an example of a saddle-ride type vehicle 1 equipped with a centrifugal clutch according to this embodiment, but this is not limited thereto, and the centrifugal clutch according to this embodiment can also be applied to other types of saddle-ride type vehicles such as three-wheeled vehicles. The centrifugal clutch according to this embodiment can also be applied to vehicles other than saddle-ride type vehicles.

The saddle-type vehicle 1 is a scooter-type vehicle having left and right step floors on which the rider places his or her feet. The saddle-type vehicle 1 has a front wheel 3 that is steered by a handlebar 2, and a rear wheel 4 that is driven by a power unit 10 that includes a drive source. In the following, the saddle-type vehicle 1 may be referred to simply as "vehicle 1."

The steering system components, including the handlebars 2 and the front wheels 3, are supported for steering by a head pipe 21 at the front end of the body frame 20. The lower front part of the power unit 10 is supported by a support bracket 7 at the bottom of the body frame 20 via a suspension link 8 so that it can swing up and down. The rear end of the power unit 10 is supported by the rear part of the body frame 20 via a rear cushion 9, which is a shock-absorbing device.

The body frame 20 includes a head pipe 21 that extends vertically at an angle so that the upper side is positioned further rearward in a side view. The body frame 20 also includes an upper down frame 22 that extends rearward from the head pipe 21, and a lower down frame 23 that extends downward from the head pipe 21 at a steeper angle than the upper down frame 22 and then bends rearward. The body frame 20 also includes a rear frame 24 that extends rearward from the rear end of the lower down frame 23.

The periphery of the body frame 20 is covered with a body cover 30. A seat 28 on which a driver (passenger) sits is provided above the rear of the body cover 30. The body cover 30 includes a pair of left and right step floors 31 on which the driver seated on the seat 28 places his/her feet, and a center tunnel 32 extending in the fore-and-aft direction of the vehicle between the pair of left and right step floors 31. The body cover 30 also includes a front body 33 connected to the front of the center tunnel 32 and the step floors 31, and a rear body 34 connected to the rear of the center tunnel 32 and the step floors 31. A space 38 is provided above the center tunnel 32 between the seat 28 and the handlebars 2 to make it easier for the driver to straddle the vehicle.

The power unit 10 includes an engine 11, which is an internal combustion engine, and a power transmission mechanism 12 that transmits the power of the engine 11 to the rear wheels 4. Figure 2 shows the internal structure of the power unit 10.

The engine 11 is a single-cylinder engine, and is configured as a horizontal engine in which the cylinder 41 protrudes horizontally from the crankcase 40 toward the front of the vehicle. The cylinder 41 includes a cylinder block 41a connected to the front end of the crankcase 40, a cylinder head 41b connected to the front end of the cylinder block 41a, and a head cover 41c that covers the front end of the cylinder head 41b.

A piston 43 is slidably disposed in the cylinder 41, and a crankshaft 14 connected to the piston 43 via a connecting rod 42 is rotatably supported in the crankcase 40. The crankshaft 14 is disposed so that its rotation axis C1 is in the left-right direction of the vehicle, and when the piston 43 reciprocates in the cylinder 41, the crankshaft 14 rotates accordingly. In addition, an ignition plug 46 is provided in the cylinder head 41b, and a camshaft 47 is rotatably provided between the cylinder head 41b and the head cover 41c. The camshaft 47 is connected to the crankshaft 14 via a cam chain 48, and rotates in conjunction with the rotation of the crankshaft 14 to drive intake and exhaust valves (not shown).

The power transmission mechanism 12 includes a transmission 50 and a centrifugal clutch 60, and transmits the power of the crankshaft 14 to the rear wheel 4. In this embodiment, the transmission 50 is configured as a V-belt type transmission (continuously variable transmission). In FIG. 2, the crankshaft 14, which is the drive shaft of the transmission 50, the driven shaft 15 of the transmission 50, the intermediate shaft 16, and the rear wheel axle 17 are shown as rotating shafts involved in the power transmission.

The transmission 50 includes a drive pulley 51 provided at one end of the crankshaft 14, which is the drive shaft of the engine 11, a driven pulley 52 provided at one end of a driven shaft 15 having a rotation axis C2 parallel to the rotation axis C1 of the crankshaft 14, and a V-belt 53 wound around these pulleys 51 and 52.

The drive pulley 51 has a drive pulley fixed half 51a fixed to the crankshaft 14, and a drive pulley movable half 51b supported by the crankshaft 14 so as to be movable in the axial direction of the crankshaft 14. When the crankshaft 14 rotates, the drive pulley movable half 51b moves in the axial direction due to the action of the centrifugal weight 54 which moves in the centrifugal direction due to the centrifugal force caused by the rotation. This causes the distance between the drive pulley fixed half 51a and the drive pulley movable half 51b to vary, and the winding diameter of the V-belt 53 sandwiched between the pulley halves 51a and 51b to change.

The driven pulley 52 has a driven pulley fixed half 52a and a driven pulley movable half 52b that are provided on a cylindrical boss portion 56 provided around the driven shaft 15. The boss portion 56 is supported by the driven shaft 15 via a plurality of bearings so as to be rotatable relative to the driven shaft 15. The driven pulley fixed half 52a is fixed (attached) to the boss portion 56, and the driven pulley movable half 52b is supported by the boss portion 56 so as to be movable in the axial direction of the driven shaft 15. The driven pulley fixed half 52a and the driven pulley movable half 52b are disposed opposite each other, and a V-belt 53 is sandwiched between them. The driven pulley movable half 52b is biased toward the driven pulley fixed half 52a by a spring 55 (biasing member).

The groove width of the drive pulley 51 and the driven pulley 52 is adjusted by the action of the centrifugal weight 54 pressing the drive pulley movable half 51b and the action of the spring 55 pressing the driven pulley movable half 52b, and the gear ratio of the transmission 50 is automatically adjusted. In addition, a centrifugal clutch 60 is disposed between the driven pulley 52 and the driven shaft 15, and the driven pulley 52 and the driven shaft 15 are connected and disconnected (disconnected/connected) via this centrifugal clutch 60. The detailed configuration of the centrifugal clutch 60 will be described later.

The intermediate shaft 16 and the rear wheel axle 17 are arranged in parallel with a gap between them behind the driven shaft 15. The rotation of the driven shaft 15 is transmitted to the intermediate shaft 16 via a reduction gear 18. The rotation of the intermediate shaft 16 is then transmitted to the rear wheel axle 17 via a reduction gear 19, and the rear wheel 4 connected to the rear wheel axle 17 is rotated around the rotation axis C3. In other words, the mechanism extending from the driven shaft 15 through the intermediate shaft 16 to the rear wheel axle 17 constitutes a reduction mechanism that reduces the speed of rotation of the driven shaft 15 by the transmission 50.

Next, the configuration of the centrifugal clutch 60 will be described. Figure 3 shows the configuration of the driven pulley 52, the centrifugal clutch 60, and the surrounding area. As shown in Figure 3, the centrifugal clutch 60 is disposed on the outer side (left side) of the driven pulley 52 in the vehicle width direction, and has a clutch inner 61, a clutch outer 62, and a clutch shoe 63 (friction member).

The clutch inner 61 is coupled (fixed) to the boss 56 as an input shaft to which the power of the engine 11 (crankshaft 14) is transmitted via the transmission 50, and rotates integrally with the boss 56. The clutch inner 61 is formed in a plate shape that expands in the radial direction, and a plurality of clutch shoes 63 are attached to the outer edge of the clutch inner 61 via weights 64. Each clutch shoe 63 is attached to the outer edge of the clutch inner 61 via weights 64 so that it moves radially outward by centrifugal force caused by the rotation of the clutch inner 61. In addition, the clutch inner 61 is provided with a spring 65 (biasing member) that biases each clutch shoe 63 (weight 64) radially inward.

The clutch outer 62 is connected (fixed) to the driven shaft 15 as the output shaft, and rotates integrally with the driven shaft 15. The clutch outer 62 is configured in a cup shape with an opening on the driven pulley 52 side, and covers the clutch inner 61, clutch shoe 63, weight 64, and spring 65.

In the centrifugal clutch 60 configured in this manner, when the rotation speed of the crankshaft 14 is equal to or greater than a predetermined value, the clutch inner 61 rotates integrally with the boss portion 56, which rotates as the power of the crankshaft 14 is transmitted by the transmission 50. Then, the weight 64 and the clutch shoe 63 move radially outward due to the centrifugal force caused by the rotation of the clutch inner 61, and the clutch shoe 63 frictionally engages with the inner surface of the clutch outer 62. As a result, the clutch outer 62 rotates, and the driven shaft 15 also rotates integrally with the clutch outer 62. In other words, the centrifugal clutch 60 is in an engaged state.

On the other hand, when the rotation speed of the crankshaft 14 is less than a predetermined value, the clutch inner 61 rotates together with the boss portion 56, which rotates as the power of the crankshaft 14 is transmitted by the transmission 50, but the centrifugal force caused by the rotation of the clutch inner 61 does not exceed the biasing force of the spring 65. Therefore, the weight 64 and clutch shoe 63 do not move radially outward due to the centrifugal force caused by the rotation of the clutch inner 61, and the moving clutch shoe 63 does not frictionally engage with the inner surface of the clutch outer 62. In other words, the centrifugal clutch 60 remains in a disengaged state.

In the centrifugal clutch 60, when the clutch shoe 63 contacts and slips against the inner surface of the clutch outer 62 due to the centrifugal force generated by the rotation of the clutch inner 61, the clutch outer 62 vibrates, and abnormal noise (also called squeal) may occur. In order to suppress (reduce) such abnormal noise, as shown in FIG. 3, the centrifugal clutch 60 is provided with a vibration-proof ring 66 on the outside of the clutch outer 62 to suppress the vibration of the clutch outer 62 and suppress the abnormal noise. In the centrifugal clutch 60, from the viewpoint of productivity and processability (ease of processing, processing freedom), it is required to suppress the abnormal noise by using a vibration-proof ring 66 with a simpler (easier) configuration. As a result of intensive research, the inventor of the present application found that abnormal noise (squeak) can be suppressed when the contact portion between the vibration-proof ring 66 and the clutch outer 62 has a portion with a large contact force in a surface contact and has contact points that are not arranged rotationally symmetrically. In other words, to ensure that such a contact structure is achieved, the contact force is ensured by bringing a portion of the anti-vibration ring 66 and the clutch outer 62 into surface contact, and then the arrangement of the contact portion between the anti-vibration ring 66 and the clutch outer 62 is devised so that the contact point is not located within an area of ±90 degrees from the contact center of the surface contact portion, and it was found that abnormal noise can be suppressed with a simpler configuration of the anti-vibration ring 66.

Specifically, the inventors of the present application have found that abnormal noise (creaking) can be suppressed by configuring the vibration-proof ring 66 so as to satisfy at least the following configuration conditions (1) to (3).
(1) The vibration-damping ring 66 has a first contact portion 71 and a second contact portion 72 that contact the outer surface of the clutch outer 62, and is configured so as not to contact the outer surface of the clutch outer 62 at any portion other than the first contact portion 71 and the second contact portion 72.
(2) The contact area between the second contact portion 72 and the outer surface of the clutch outer 62 is smaller than the contact area between the first contact portion 71 and the outer surface of the clutch outer 62 .
(3) When the region of the outer surface of the clutch outer 62 that is within ±90 degrees of the contact center of the first contact portion 71 in the circumferential direction is defined as a first region R1, and the region other than the first region R1 is defined as a second region R2, the second contact portion 72 is positioned on the vibration-damping ring 66 so as to contact the second region R2.
An example of the configuration of the vibration-isolating ring 66 of this embodiment will now be described.

[Configuration Example 1]
Fig. 4 shows a first configuration example of the vibration-isolating ring 66 of this embodiment. Fig. 4 shows the clutch outer 62 and the vibration-isolating ring 66 provided on the outer side thereof, as viewed from the driven pulley 52 side.

As shown in FIG. 4, the vibration-proof ring 66 of the configuration example 1 has one first contact portion 71 and multiple (two) second contact portions 72a-72b, and is configured so that the portions other than the first contact portion 71 and the second contact portions 72a-72b do not contact the outer surface of the clutch outer 62. The first contact portion 71 is an arc-shaped portion, and is in surface contact with the outer surface of the clutch outer 62. On the other hand, each of the second contact portions 72a-72b is a part (preferably a vertex) of the protruding portion 66a that protrudes toward the outer surface of the clutch outer 62, and is in point contact (preferably line contact) with the outer surface of the clutch outer 62. That is, each of the second contact portions 72a-72b contacts the outer surface of the clutch outer 62 with a contact area smaller than that of the first contact portion 71. In this way, the vibration-proof ring 66 of the configuration example 1 satisfies the above configuration conditions (1) and (2).

In addition, in the vibration-damping ring 66 of configuration example 1, the second contact portions 72a-72b are provided so as to contact the second region R2 on the outer surface of the clutch outer 62. As described above, when the region on the outer surface of the clutch outer 62 that is within ±90 degrees of the contact center of the first contact portion 71 in the circumferential direction is defined as the first region R1, the second region R2 can be defined as the region on the outer surface of the clutch outer 62 other than the first region R1. The contact center of the first contact portion 71 can be defined as the circumferential center (center of gravity) of the first contact portion 71 that is in surface contact with the outer surface of the clutch outer 62. In this way, the vibration-damping ring 66 of configuration example 1 satisfies the above configuration condition (3).

Here, in the case where the anti-vibration ring 66 of this embodiment has a plurality of second contact portions 72, an additional condition (4) may be that the angle θ between the two second contact portions 72 that are furthest apart in the circumferential direction among the plurality of second contact portions 72 is less than 180 degrees. In the anti-vibration ring 66 of configuration example 1 shown in FIG. 4, only two second contact portions 72a-72b are provided, but since the angle θ between the two second contact portions 72a-72b is less than 180 degrees, this configuration condition (4) is also satisfied.

[Configuration Example 2]
Fig. 5 shows a second configuration example of the vibration-isolating ring 66 of this embodiment. Fig. 5 shows the clutch outer 62 and the vibration-isolating ring 66 provided on the outer side thereof, as viewed from the driven pulley 52 side.

As shown in FIG. 5, the vibration-proof ring 66 of the second configuration example 2 has one first contact portion 71 and multiple (two) second contact portions 72c to 72d, and is configured so that the portions other than the first contact portion 71 and the second contact portions 72c to 72d do not contact the outer surface of the clutch outer 62. The first contact portion 71 is an arc-shaped portion that is in surface contact with the outer surface of the clutch outer 62. On the other hand, each of the second contact portions 72c to 72d is part of the flat portion 66b that is flat so as to contact the outer surface of the clutch outer 62, and is in point contact (preferably line contact) with the outer surface of the clutch outer 62. That is, each of the second contact portions 72c to 72d contacts the outer surface of the clutch outer 62 with a contact area smaller than that of the first contact portion 71. In this way, the vibration-proof ring 66 of the second configuration example 2 satisfies the above configuration conditions (1) to (2).

In addition, in the anti-vibration ring 66 of configuration example 2, the second contact portions 72c-72d are provided so as to contact the second region R2 on the outer surface of the clutch outer 62, and the above-mentioned configuration requirement (3) is satisfied. Furthermore, in the anti-vibration ring 66 of configuration example 2, the angle θ between the two second contact portions 72c-72d that are furthest apart is less than 180 degrees, and therefore the above-mentioned configuration requirement (4) is also satisfied.

[Configuration Example 3]
Fig. 6 shows a third configuration example of the vibration-isolating ring 66 of this embodiment. Fig. 6 shows the clutch outer 62 and the vibration-isolating ring 66 provided on the outer side thereof, as viewed from the driven pulley 52 side.

As shown in FIG. 6, the vibration-proof ring 66 of the configuration example 3 has one first contact portion 71 and multiple (two) second contact portions 72e to 72f, and is configured so that the portions other than the first contact portion 71 and the second contact portions 72e to 72f do not contact the outer surface of the clutch outer 62. The first contact portion 71 is an arc-shaped portion and is in surface contact with the outer surface of the clutch outer 62. On the other hand, each of the second contact portions 72e to 72f is a part (preferably a vertex) of the protruding portion 66a that protrudes toward the outer surface of the clutch outer 62, and is in point contact (preferably line contact) with the outer surface of the clutch outer 62. That is, each of the second contact portions 72e to 72f contacts the outer surface of the clutch outer 62 with a contact area smaller than that of the first contact portion 71. In this way, the vibration-proof ring 66 of the configuration example 3 satisfies the above configuration conditions (1) to (2).

In addition, in the anti-vibration ring 66 of configuration example 3, the second contact portions 72e-72f are provided so as to contact the second region R2 on the outer surface of the clutch outer 62, and the above-mentioned configuration requirement (3) is satisfied. Furthermore, in the anti-vibration ring 66 of configuration example 3, the angle θ between the two second contact portions 72e-72f that are furthest apart is less than 180 degrees, and therefore the above-mentioned configuration requirement (4) is also satisfied.

Here, in the vibration-proof ring 66 of the above-mentioned configuration example 1, as shown in FIG. 4, the angle between the contact center of the first contact portion 71 and each of the second contact portions 72 is the same for the two most distant second contact portions 72a to 72b. In other words, the angle between the contact center of the first contact portion 71 and one of the second contact portions 72a is the same as the angle between the contact center of the first contact portion 71 and the other of the second contact portions 72b. On the other hand, in the vibration-proof ring 66 of the configuration example 3, as shown in FIG. 6, the angle between the contact center of the first contact portion 71 and each of the second contact portions 72 is different for the two most distant second contact portions 72e to 72f. In other words, the angle α between the contact center of the first contact portion 71 and one of the second contact portions 72e is different from the angle β between the contact center of the first contact portion 71 and the other of the second contact portions 72f. In such a configuration example 3, as in the configuration example 1, the effect of suppressing abnormal noise (squeak) can be obtained.

In addition, each of the second contact portions 72e to 72f in the vibration-proof ring 66 in configuration example 3 is configured as part (the apex) of the protruding portion 66a that protrudes toward the outer surface of the clutch outer 62, but as in configuration example 2, they may be configured as part of the flat portion 66b that is configured in a flat shape so as to contact the outer surface of the clutch outer 62.

[Configuration Example 4]
Fig. 7 shows a fourth configuration example of the vibration-isolating ring 66 of this embodiment. Fig. 7 shows the clutch outer 62 and the vibration-isolating ring 66 provided on the outer side thereof, as viewed from the driven pulley 52 side.

As shown in FIG. 7, the vibration-proof ring 66 of the configuration example 4 has one first contact portion 71 and one second contact portion 72g, and is configured so that the portions other than the first contact portion 71 and the second contact portion 72g do not contact the outer surface of the clutch outer 62. The first contact portion 71 is a portion configured in an arc shape and is in surface contact with the outer surface of the clutch outer 62. On the other hand, each second contact portion 72g is a part (preferably a vertex) of the protruding portion 66a protruding toward the outer surface of the clutch outer 62, and is in point contact (preferably line contact) with the outer surface of the clutch outer 62. That is, the second contact portion 72g contacts the outer surface of the clutch outer 62 with a contact area smaller than that of the first contact portion 71. In addition, in the vibration-proof ring 66 of the configuration example 4, the second contact portion 72g is provided so as to contact the second region R2 on the outer surface of the clutch outer 62. In this way, the vibration-proof ring 66 of configuration example 4 is configured to have only one second contact portion 72 and satisfies the above configuration conditions (1) to (3).

Here, in the anti-vibration ring 66 of configuration example 4, the angle γ between the contact center of the first contact portion 71 and the second contact portion 72g is configured to be less than 180 degrees, but the angle γ may be 180 degrees. That is, the second contact portion 72g may be provided on the part of the anti-vibration ring 66 opposite the contact center of the first contact portion 71. Also, the second contact portion 72g in the anti-vibration ring 66 of configuration example 4 is configured as a part (apex) of the protruding portion 66a that protrudes toward the outer surface of the clutch outer 62, but as in configuration example 2, it may be configured as a part of the flat portion 66b that is configured in a flat shape so as to contact the outer surface of the clutch outer 62.

[Configuration Example 5]
Fig. 8 shows a fifth configuration example of the vibration-isolating ring 66 of this embodiment. Fig. 8 shows the clutch outer 62 and the vibration-isolating ring 66 provided on the outer side thereof as viewed from the driven pulley 52 side.

As shown in FIG. 8, the vibration-proof ring 66 of the configuration example 5 has one first contact portion 71 and multiple (three) second contact portions 72h to 72j, and is configured so that the portions other than the first contact portion 71 and the second contact portions 72h to 72j do not contact the outer surface of the clutch outer 62. The first contact portion 71 is a portion configured in an arc shape and is in surface contact with the outer surface of the clutch outer 62. On the other hand, each of the second contact portions 72h to 72j is a part (preferably a vertex) of the protruding portion 66a protruding toward the outer surface of the clutch outer 62, and is in point contact (preferably line contact) with the outer surface of the clutch outer 62. That is, each of the second contact portions 72h to 72j contacts the outer surface of the clutch outer 62 with a contact area smaller than that of the first contact portion 71. In addition, in the vibration-proof ring 66 of the configuration example 5, each of the second contact portions 72h to 72j is provided so as to contact the second region R2 on the outer surface of the clutch outer 62. In this way, the vibration-proof ring 66 of configuration example 5 is configured to have three second contact portions 72 and satisfies the above configuration conditions (1) to (3).

In addition, in the anti-vibration ring 66 of configuration example 5, the angle θ between the two second contact portions 72h, 72j that are farthest apart among the multiple (three) second contact portions 72h-72j is less than 180 degrees. Therefore, the above configuration requirement (4) is also satisfied. Here, each of the second contact portions 72h-72j in the anti-vibration ring 66 of configuration example 5 is configured as part (apex) of the protruding portion 66a that protrudes toward the outer surface of the clutch outer 62, but as in configuration example 2, it may be configured as part of the flat portion 66b that is configured in a flat shape so as to contact the outer surface of the clutch outer 62.

[effect]
Next, the effect obtained by applying the anti-vibration ring 66 of this embodiment to the centrifugal clutch 60 will be described. Fig. 9 is a graph showing the abnormal noise (squeak) of the centrifugal clutch 60 to which the anti-vibration ring 66 of this embodiment (configuration examples 1 to 5 above) is applied. The horizontal axis of the graph in Fig. 9 indicates frequency, and the vertical axis indicates sound pressure (PS). For comparison, Fig. 9 also shows the abnormal noise of the centrifugal clutch 60 to which the anti-vibration ring 66 is not applied.

As shown in FIG. 9, it was confirmed that in the centrifugal clutch 60 to which the anti-vibration ring 66 of this embodiment (configuration examples 1 to 5 above) is applied, abnormal noise (squeak) is significantly suppressed compared to a centrifugal clutch 60 to which the anti-vibration ring 66 is not applied. In other words, by applying the anti-vibration ring 66 configured to satisfy the above configuration conditions to the centrifugal clutch 60, the abnormal noise (squeak) of the centrifugal clutch 60 can be suppressed. Furthermore, the anti-vibration ring 66 of this embodiment can suppress abnormal noise with a simpler (easier) configuration compared to the anti-vibration ring (anti-vibration cover) of Patent Document 1, and is therefore advantageous in terms of productivity and processability.

Summary of the embodiment
1. The centrifugal clutch (e.g., 60) of the above embodiment is
A clutch inner (e.g., 61) that is coupled to an input shaft (e.g., 56) to which power is transmitted and rotates integrally with the input shaft;
A clutch outer (e.g., 62) coupled to an output shaft (e.g., 15) and rotating integrally with the output shaft;
a clutch shoe (e.g., 63) that is supported by the clutch inner and moves by centrifugal force caused by rotation of the clutch inner to frictionally engage with the inner surface of the clutch outer;
A vibration-isolating ring (e.g., 66) provided on the outside of the clutch outer;
Equipped with
the vibration-proof ring has a first contact portion (e.g., 71) that contacts the outer surface of the clutch outer, and a second contact portion (e.g., 72) that contacts the outer surface with a contact area smaller than that of the first contact portion, and is configured not to contact the outer surface at any portion other than the first contact portion and the second contact portion,
When a region of the outer surface of the clutch outer that is within ±90 degrees in the circumferential direction from the contact center of the first contact portion is defined as a first region (e.g., R1), and a region other than the first region is defined as a second region (e.g., R2), the second contact portion is positioned on the vibration-damping ring so as to contact the second region.
According to this embodiment, the abnormal noise (squeak) of the centrifugal clutch can be suppressed by using an anti-vibration ring with a simpler (easier) configuration, which is advantageous in terms of productivity and processability.

2. In the above embodiment,
the first contact portion of the vibration-proof ring is a portion that comes into surface contact with the outer surface of the clutch outer,
The second contact portion of the vibration-proof ring is a portion that comes into line contact with the outer surface of the clutch outer.
According to this embodiment, the abnormal noise (squeak) of the centrifugal clutch can be suppressed by using an anti-vibration ring with a simpler (easier) configuration.

3. In the above embodiment,
The vibration-proof ring has a plurality of second contact portions that contact the second region on the outer surface of the clutch outer.
According to this embodiment, the abnormal noise (squeak) of the centrifugal clutch can be more effectively suppressed, and it is also advantageous in terms of the rigidity balance and weight balance of the centrifugal clutch.

4. In the above embodiment,
An angle between two of the second contact portions that are farthest apart in the circumferential direction is less than 180 degrees.
According to this embodiment, the abnormal noise (squeal) of the centrifugal clutch can be more effectively suppressed.

5. In the above embodiment,
In the circumferential direction, the angle between one of the two second contact portions and the contact center of the first contact portion is the same as the angle between the other of the two second contact portions and the contact center of the first contact portion.
According to this embodiment, the abnormal noise (squeak) of the centrifugal clutch can be more effectively suppressed, and this is also advantageous in terms of the rigidity balance and weight balance of the centrifugal clutch.

6. In the above embodiment,
In the circumferential direction, an angle between one of the two second contact portions and a contact center of the first contact portion is different from an angle between the other of the two second contact portions and the contact center of the first contact portion.
According to this embodiment, the abnormal noise (squeak) of the centrifugal clutch can be more effectively suppressed, and the anti-vibration ring can be more advantageously processed (ease of processing, degree of freedom in processing).

7. In the above embodiment,
The vibration-proof ring has a protruding portion (e.g., 66a) that protrudes toward the outer surface of the clutch outer member,
The second contact portion is formed at a part of the protruding portion.
According to this embodiment, the abnormal noise (squeak) of the centrifugal clutch can be more effectively suppressed, and the anti-vibration ring can be more advantageously processed (ease of processing, degree of freedom in processing).

8. In the above embodiment,
The vibration-proof ring has a flat portion (e.g., 66b) that is configured in a flat shape,
The second contact portion is formed on a part of the flat surface.
According to this embodiment, the abnormal noise (squeak) of the centrifugal clutch can be more effectively suppressed, and the anti-vibration ring can be more advantageously processed (ease of processing, degree of freedom in processing).

The present invention is not limited to the above-described embodiments, and various modifications and variations are possible without departing from the spirit and scope of the present invention.

1: vehicle, 10: power unit, 11: engine, 12: power transmission mechanism, 60: centrifugal clutch, 61: clutch inner, 62: clutch outer, 63: clutch shoe, 64: weight, 65: spring, 66: vibration-proof ring

Claims (9)

A centrifugal clutch,
a clutch inner coupled to an input shaft to which power is transmitted and rotated integrally with the input shaft;
a clutch outer coupled to an output shaft and rotating integrally with the output shaft;
a clutch shoe supported by the clutch inner and moved by centrifugal force caused by rotation of the clutch inner to frictionally engage with an inner surface of the clutch outer;
a vibration-isolating ring provided on the outer side of the clutch outer;
Equipped with
the vibration-proof ring has a first contact portion that contacts an outer surface of the clutch outer, and a second contact portion that contacts the outer surface with a contact area smaller than that of the first contact portion, and is configured not to contact the outer surface at any portion other than the first contact portion and the second contact portion,
A centrifugal clutch characterized in that, when a region of the outer surface of the clutch outer that is within ±90 degrees in the circumferential direction from the contact center of the first contact portion is defined as a first region, and a region other than the first region is defined as a second region, the second contact portion is positioned on the vibration-damping ring so as to contact the second region. the first contact portion of the vibration-proof ring is a portion that comes into surface contact with the outer surface of the clutch outer,
2. The centrifugal clutch according to claim 1, wherein the second contact portion of the anti-vibration ring is a portion that makes line contact with the outer surface of the clutch outer member. The centrifugal clutch according to claim 1, characterized in that the vibration-proof ring has a plurality of second contact portions that contact the second region on the outer surface of the clutch outer. The centrifugal clutch according to claim 3, characterized in that the angle between the two second contact portions that are farthest apart in the circumferential direction among the plurality of second contact portions is less than 180 degrees. The centrifugal clutch according to claim 4, characterized in that, in the circumferential direction, the angle between one of the two second contact portions and the contact center of the first contact portion is the same as the angle between the other of the two second contact portions and the contact center of the first contact portion. The centrifugal clutch according to claim 4, characterized in that, in the circumferential direction, an angle between one of the two second contact portions and the contact center of the first contact portion is different from an angle between the other of the two second contact portions and the contact center of the first contact portion. the vibration-proof ring has a protruding portion protruding toward the outer surface of the clutch outer,
2. The centrifugal clutch according to claim 1, wherein the second contact portion is formed on a part of the protruding portion. The vibration-proof ring has a flat portion formed in a flat shape,
2. The centrifugal clutch according to claim 1, wherein the second contact portion is formed on a part of the flat surface portion. A vehicle equipped with a centrifugal clutch according to any one of claims 1 to 8.