JPH0239059Y2 - - Google Patents

Description

[Detailed description of the invention] (Field of industrial application) This invention consists of a member that supports the friction plate and transmits power between the friction plate and the output take-off gear, and an internal gear that meshes with the output take-off gear. This invention relates to a centrifugal clutch that is loosely fitted to a clutch hub and is comprised of two members, an inner and outer member, and a clutch hub that moves a friction plate in the clutch ON direction when the engine is started.

(Prior Art) For example, in some two-wheeled motor vehicles or three-wheeled motor vehicles, a centrifugal clutch is provided at the end of a crankshaft that is an input shaft.

In this case, the centrifugal clutch is, for example,
There is one disclosed in Japanese Utility Model Application Publication No. 56-75331.
The one disclosed in the above publication has a
A clutch housing that rotates in synchronization is provided, an output take-out gear is loosely fitted to the other outer periphery of the input shaft, and an inner periphery of the clutch housing is provided.
A clutch plate is arranged that can move forward and backward in the axial direction.

On the other hand, an internal gear that meshes with the output extraction gear is supported on the outer periphery of the base of the clutch housing, and a clutch hub that supports the friction plate is provided on the outer periphery of this internal gear.

The reason why two members, the internal gear and the clutch hub, are provided between the friction plate and the output extraction gear is that the two plates are connected by pressure contact by a push-button operation. This is to start the engine (drive source).

Therefore, as shown in FIG. 5, an engaging cam 36 integral with the gear is protruded from the outer periphery of the internal gear 14, and a connecting cam groove 35 is formed on the inner periphery of the clutch hub 13. More specifically, the connecting cam groove 35 is connected to a pair of first and second engaging opposing walls 35a and 35b that face each other at a distance that allows constant movement in the circumferential direction relative to the engaging cam 36. The internal gear 14 consists of an inclined cam surface 35c facing the coupling cam 36 as a surface inclined in the axial direction, and an output take-out gear that rotates by a key operation.
is rotated in the direction of arrow X, and due to this rotation, the engagement cam 36 rides on the inclined cam surface 35c of the connecting cam groove 35, and the clutch hub 13 is moved in the clutch ON direction (toward the back of the paper in FIG. 5) to start the clutch hub 13. When the pushing clutch is connected, the engagement cam 36 also pushes the cam surface 35c in the rotational direction to start the engine.

On the other hand, once the start-up is completed, the rotation is preceded by the generation of torque from the engine, and as the clutch hub 13 rotates in the direction of the arrow Y, as shown in FIG. 36 returns along the inclined cam surface 35c, engages with the first engaging opposing wall 35a, and transmits power from the internal gear 14 to the output side in a normal transmission state.

The clutch hub 13 and the internal gear 14 are configured as described above, but in the conventional case, power was transmitted between the internal gear 14 and the clutch hub 13 only by the engaging cam 36 and the connecting cam groove 35. However, the following problems arose.

In other words, when the transmission is in neutral, for example, idling, the rotation (centrifugal force) is low and the clutch is automatically disengaged.
In addition to connecting both friction plates 11 and 12, the clutch hub 13 is loosely fitted to the internal gear 14, so that the friction plate 12 tilts and makes partial contact with the clutch plate 11, connecting both plates 11 and 12. 13 rotates due to this rotation.

At this time, since the internal gear 14 is not loaded and is in an idle state, the internal gear 14 rotates with the clutch hub 13 and enters the state shown in FIG. 6, which is similar to the normal transmission state.

However, since the internal gear 14 is in an idle state, it not only rotates along with it, but also rotates the clutch hub 13 side due to fluctuations in engine rotation, and as a result, the engagement cam 36
The first engaging wall 35a of the connecting cam groove 35 exhibits a peculiar phenomenon in which it comes into contact with and separates from the first engaging wall 35a, and this causes the generation of a tapping sound.

(Purpose of the invention) This invention was made in view of the above-mentioned problem, and its purpose is to suppress the occurrence of the above-mentioned hitting sound.

(Structure of the invention) In order to achieve the above object, this invention consists of an internal gear or a clutch hub made of an elastic body, and the above-mentioned engagement cam and an opposing wall for engagement come into contact with each other in response to rotational driving force from the clutch hub. A buffer member is provided at the front to contact the mating clutch hub or internal gear from the circumferential direction.

(Example) An example of this invention will be described below with reference to the drawings.

FIG. 1 shows an example of a small two-wheeled motor vehicle.

In FIG. 1, E is an engine, and one side of its crankcase 1 is shown in the drawing. A crankshaft (input shaft) 2 is rotatably supported in the crankcase 1, and a countershaft 3 and a power take-off shaft 4 are each rotatably supported in parallel with the crankshaft 2.

In the above-mentioned countershaft 3, variable speed drive gears 5A, 5B, and 5C from the first stage to the third stage are arranged in the drawing, and a buffer spring 6 is installed at the end of the countershaft 3 that corresponds to the outside of the crankcase 1. A second output extraction gear 7 is attached.

On the other hand, the power take-off shaft 4 has the above-mentioned speed change drive gear 5.
Shift driven gears 8A, 8B, and 8C that mesh with gears A, 5B, and 5C, respectively, are arranged, and thus constitute a transmission capable of shifting gears including gears not shown.

Here, a kick device (not shown) is connected to the first speed change driven gear 8A disposed at the end shown in the drawing of the power take-off shaft 4.

On the other hand, a clutch cover 9 is attached to one side of the crankcase 1, and a centrifugal clutch C, which will be described below, is disposed within the clutch cover 9.

The centrifugal clutch C is provided at the end of the crankshaft 2, and its main members are as follows.

In other words, 10 is the clutch housing, 11 is the clutch plate, 12 is the friction plate,
13 is the clutch hub, 14 is the internal gear,
15 indicates a garter spring.

Among the main members mentioned above, the clutch housing 10 is made of die-cast aluminum, and its inner periphery is connected to the end of the crankshaft 2 by a spline, and is prevented from coming off by a nut 16.

This clutch housing 10 includes a central housing boss 17 and a housing side wall 1 on its outer periphery.
8, and an outermost housing outer peripheral wall 19, in which a spring receiver 20 for setting the garter spring 15 is protruded from the inner wall of the housing side wall 18, and the spring A cam surface 21 is formed at a location corresponding to the outer periphery of the receiver cylinder 20 and is inclined toward the outer periphery in the direction of the clutch plate 11. This cam surface 21 forms a conical surface as a whole.

On the other hand, as shown in FIG. 2, housing-side protrusions 22 are provided on the inner circumference of the housing outer peripheral wall 19 in an intermittent arrangement in the circumferential direction. As shown in the figure, from the garter spring 15 side, the first end clutch plate 23, the two intermediate clutch plates 11, 1
1 and the second end clutch plate 25 are engaged and arranged in the above order, and each is slidable only in the axial direction.

Here, reference numeral 26 denotes a snap ring, which is provided on the housing side protrusion 22, and between this snap ring 26 and the second end clutch plate 25 is a disc spring 27 that biases the clutch in the ON direction.
is placed, while the second plate spring 27 is
In order to bias the end clutch plate 25 in the clutch OFF direction, a release pin 29 is provided on the guide boss 28 between the housing side protrusions 22, and this release pin 29 is actuated to move forward and backward in response to foot operation. It is operated by a clutch operating mechanism 30.

Furthermore, locking pawls 31 are formed on the outer periphery of the clutch hub 13, and the friction plates 12 are arranged on these locking pawls 31 so as to be slidable in the axial direction. This friction plate 12
The core material is SPCC, and cork-based friction material 32 is provided on both sides and the outer peripheral end surface.

Here, a pressing flange 33 that faces the friction plate 12 is protruded from one end of the outer periphery of the clutch hub 13, and as shown in FIG. Connection cam grooves 35 are formed in an equally divided arrangement.

Each of these connecting cam grooves 35 includes a pair of first and second engaging opposing walls 35a, which face an engaging cam 36 integrally protruding from the outer periphery of the internal gear 14 with a movement interval in the circumferential direction; 35b, and an inclined cam surface 35c that faces the engagement cam 36 as a surface inclined in the axial direction.

In this case, as shown in FIG.
The operating force is transmitted to the first output extraction gear 37 on the outer periphery of the crankshaft 2 via the first speed change drive gear 5A and the second output extraction gear 7, and the rotational force is transmitted from the first output extraction gear 37 to the internal gear 14. As a result, the engaging cam 36 formed on the internal gear 14 rides on the inclined cam surface 35c of the connecting cam groove 35 as it rotates in the direction of arrow X in FIG. As a result, as shown in FIG. 2, the rotational force is transmitted from the internal gear 14 to the clutch hub 13 while the engagement cam 36 is close to the second engagement facing wall 35b.
When the clutch is started, the clutch hub 13 moves in the direction of arrow Z in Figure 1.
When the pressure flange 33 presses the friction plate 12,
The clutch is turned ON and the engine is started.

On the other hand, when the engine (drive source) starts, power is transmitted from the crankshaft 2 through the clutch housing 10, and as the clutch hub 13 side rotates first as shown by arrow Y in FIG. 3, the connecting cam groove 35 comes into contact with the engagement cam 36, and the second
The starting state shown in the figure returns to the normal transmission state shown in FIG.

The centrifugal clutch C is constructed as described above, and is particularly characterized in that a shock absorber is provided between the internal gear 14 and the clutch hub 13 as shown in FIG.

That is, a buffer notch groove 34 is formed between each of the connection cam grooves 35, and a buffer rubber (buffer member) protruding from the outer periphery of the internal gear 14 is provided in each buffer notch groove 34. ) 41 are located correspondingly, and in this case, the cushioning rubber 41
is L-shaped and has a buffer portion 41a at its tip, and in particular, this buffer portion 41a is arranged in a position that precedes the engagement cam 36 abutting the first engagement opposing wall 35a, as shown in FIG. Opposed buffer wall 34
In the normal transmission state, after the buffer portion 41a is sufficiently elastically deformed as shown in FIG. 3, the engagement cam 36 comes into contact with the first opposing wall 35a for engagement.

Therefore, in the above configuration, when the transmission is in neutral and idling, power is transmitted from the crankshaft 2 shown in FIG. 1 to the clutch plates 11, 23, and 25 through the clutch housing 10. The output side, which is the first output extraction gear 37 side, is in a neutral state and has stopped rotating.

Here, the engagement cam 36 vibrates reciprocatingly with respect to the connection cam groove 35 as the friction plate 12 is rotated by the clutch plates 11, 23, 25 with rotational fluctuations as described above. However, here, before the engagement cam 36 contacts the first engagement opposing wall 35a, as shown in FIG. 35a, the buffer portion 41a is compressed and elastically deformed to an intermediate degree as shown in FIGS. 4 and 3, thereby exerting a buffer function. As a result, the occurrence of hitting sounds can be suppressed.

In addition, in the above embodiment, the clutch plate 11
As shown in Fig. 1, the clutch housing 1
Only the plate-side protrusion 11a that engages with the housing-side protrusion 22 of No. 0 is made about three times thicker than the other core parts to form a heat transfer promoting part, and contacts the housing-side protrusion 22 over a wide area. It's like this. The clutch plate 11 is made of die-cast aluminum. This can prevent clutch seizure. In addition, as shown in FIG. 1, a ball bearing 42 is provided at a substantially intermediate position in the axial direction on the inner circumference of the internal gear 14, and by supporting the clutch hub 13 more reliably, the friction plate 12 is moved when the clutch is OFF. It is designed to suppress the tilt.
Furthermore, in the above embodiment, the internal gear 14
Although the engaging cam 36 is provided protrudingly on the clutch hub 13 and the connecting cam groove 35 is provided on the clutch hub 13, the engaging cam 36 may be provided protrudingly on the clutch hub 13 and the connecting cam groove 35 may be provided on the internal gear 14. Further, the buffer rubber 41 is attached to the clutch hub 13, contrary to the above embodiment.
It may be placed on the side. Furthermore, this invention can also be applied to the centrifugal clutch shown in FIG. 1 in the above-mentioned publication.

(Effects of the invention) As explained above, according to this invention, before the engagement cam and the opposing wall for engagement come into contact with the internal gear or the clutch hub due to the rotational driving force from the clutch hub side. Since a buffer member is provided that contacts the mating clutch hub or internal gear from the circumferential direction, the occurrence of the above-mentioned hitting noise can be suppressed.

[Brief explanation of the drawing]

Figure 1 is a sectional view of a power transmission system showing an embodiment of this invention, and Figure 2 is a diagram showing the power transmission system shown in Fig.
3 is a sectional view of the line in FIG. 1 in a buffer state or normal transmission state; FIG. 4 is a sectional view of the line in FIG.
FIG. 5 is a sectional view showing the structure of the conventional example in a torque state, and FIG. 6 is a sectional view showing it in a normal transmission state. E... Engine (drive source), 10... Clutch housing, 11, 23, 25... Clutch plate, 12... Friction plate, 13...
Clutch hub, 14...Internal gear, 35
a...First engagement opposing wall, 35b...Second engagement opposing wall, 36...Engagement cam, 41...Buffer rubber (buffer member).

Claims (1)

[Scope of utility model registration request] It has a clutch hub that receives rotational driving force from a drive source via a clutch plate and a friction plate, and an internal gear connected to a load, and an engagement cam is provided protruding from either the internal gear or the clutch hub. , on the other hand, in a clutch provided with a pair of opposing engaging walls that face the engaging cam at a movement interval in the circumferential direction, the internal gear or the clutch hub is made of an elastic body and is rotatably driven from the clutch hub side. A centrifugal clutch characterized in that a buffer member is provided which contacts a mating clutch hub or an internal gear from the circumferential direction before the engaging cam and the opposing engaging wall come into contact with each other in response to a force.