Power transmission device

Abstract

A power transmission device (K) is provided with: a clutch member (4) that holds a plurality of driven-side clutch plates (7); a pressure member (5) capable of pressing the drive-side clutch plate (6) and the driven-side clutch plate (7) together with the clutch member (4); and a centrifugal clutch unit (9) that applies a first pressing contact force to the drive-side clutch plate (6) and the driven-side clutch plate (7) as the weight member (10) moves from the inner-diameter-side position to the outer-diameter-side position. When the counterweight member (10) is located at the outer diameter side position, the driving-side clutch plate (6) and the driven-side clutch plate (7) are pressed and contacted with each other, so that the driving force of the engine (E) can be transmitted to the driving wheel (W). A pressing contact force increasing mechanism (20) that generates a second pressing contact force that increases the pressing contact force between the drive-side clutch plate (6) and the driven-side clutch plate (7) as the rotational speed of the engine (E) increases; and an auxiliary cam mechanism (30) that generates a third pressing contact force that increases the pressing contact force between the drive-side clutch plate (6) and the driven-side clutch plate (7) when the clutch member (4) rotates relative to the pressure member (5).

Description

Technical Field

[0001] The present invention relates to a power transmission device capable of arbitrarily transmitting or cutting off the rotational force of an input member to an output member. Background Art

[0002] As a conventional power transmission device, for example, as disclosed in Patent Document 1, a centrifugal clutch unit having a weight component is proposed, and the weight component is moved from an inner diameter side position to an outer diameter side position by centrifugal force generated by the rotation of the clutch housing, thereby making the driving side clutch plate and the driven side clutch plate press and contact each other. According to this conventional power transmission device, the clutch housing rotates along with the drive of a driving source such as an engine, thereby applying centrifugal force to the weight component, making the driving side clutch plate and the driven side clutch plate press and contact each other, and transmitting the driving force of the engine to the wheels.

[0003] In addition, according to the above-mentioned conventional power transmission device, a pressing contact force increasing mechanism is provided, which generates a cam thrust force that increases the pressing contact force between the driving side clutch plate and the driven side clutch plate when the rotational force input to the input member is in a state that can be transmitted to the output member. Therefore, when the driver operates the clutch to make the driving side clutch plate and the driven side clutch plate press contact with each other, the operating force can be reduced to perform smooth power transmission.

[0004] Prior art literature

[0005] Patent Document 1: International Publication No. 2013 / 183588 Summary of the invention

[0006] Problems to be solved by the invention

[0007] However, in the above-mentioned previous power transmission device, in order to transmit the driving force of the engine to the wheels, the pressing contact force between the driving side clutch plate and the driven side clutch is increased by using a pressing contact force increasing mechanism. However, if the pressing contact force between the driving side clutch plate and the driven side clutch can be further increased, the driving force of the engine can be transmitted to the wheels more efficiently.

[0008] The present invention has been made in view of the above-mentioned problems, and an object of the present invention is to provide a power transmission device capable of transmitting the driving force of a driving source to wheels more efficiently.

[0009] Means for solving problems

[0010] The power transmission device of the present invention comprises: a clutch component housed in a clutch housing, the clutch housing rotates together with an input component rotated by a driving force of a driving source and holds a plurality of driving-side clutch plates, the clutch component is connected to an output component capable of rotating a wheel, and the clutch component holds a plurality of driven-side clutch plates alternately arranged with the driving-side clutch plates; a pressure component capable of pressing the driving-side clutch plates and the driven-side clutch plates together with the clutch component; a centrifugal clutch unit having a weight component, the weight component being capable of moving from an inner diameter side position to an outer diameter side position by a centrifugal force generated accompanying the rotation of the clutch housing, the centrifugal clutch unit applying a first pressing contact force to the driving-side clutch plates and the driven-side clutch plates as the weight component moves from the inner diameter side position to the outer diameter side position , when the counterweight component is located at the outer diameter side position, the centrifugal clutch unit causes the driving side clutch plate and the driven side clutch plate to be pressed into contact with each other, thereby becoming a state in which the driving force of the driving source can be transmitted to the wheel, and when the counterweight component is located at the inner diameter side position, the centrifugal clutch unit releases the first pressing contact force applied to the driving side clutch plate and the driven side clutch plate, thereby cutting off the transmission of the driving force of the driving source to the wheel; a pressing contact force increasing mechanism generates a second pressing contact force that increases the pressing contact force between the driving side clutch plate and the driven side clutch plate as the rotation speed of the driving source increases; and an auxiliary cam mechanism generates a third pressing contact force that increases the pressing contact force between the driving side clutch plate and the driven side clutch plate when the clutch component rotates relative to the pressure component.

[0011] The power transmission device of the present invention is provided with a centrifugal clutch unit for applying a first pressing contact force and a pressing contact force increasing mechanism for generating a second pressing contact force, and also has an auxiliary cam mechanism, which generates a third pressing contact force for increasing the pressing contact force between the driving side clutch plate and the driven side clutch plate when the clutch member rotates relative to the pressure member. According to the above method, in addition to the first pressing contact force and the second pressing contact force, a third pressing contact force is generated on the driving side clutch plate and the driven side clutch plate according to the operating state of the vehicle, so that the pressing contact force of the driving side clutch plate and the driven side clutch plate can be maximized. As a result, the driving force of the driving source can be transmitted to the wheels more efficiently.

[0012] Effects of the Invention

[0013] According to the present invention, it is possible to provide a power transmission device capable of more efficiently transmitting the driving force of a driving source to wheels. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 It is an external view showing the power transmission device according to the first embodiment.

[0015] Figure 2 It is along Figure 1 Cross-sectional view along line II-II.

[0016] Figure 3 It is along Figure 1 Cross-sectional view along line III-III.

[0017] Figure 4 It is a perspective view showing the clutch housing according to the first embodiment.

[0018] Figure 5A It is a top view of the clutch member of the first embodiment.

[0019] Figure 5B It is an exploded perspective view of the clutch member according to the first embodiment.

[0020] Figure 6 It is a three-view diagram showing the first clutch member according to the first embodiment.

[0021] Figure 7 It is a perspective view showing the first clutch member according to the first embodiment.

[0022] Figure 8 It is a three-view diagram showing the second clutch member according to the first embodiment.

[0023] Fig. 9 It is along Figure 8 Cross-sectional view along line IX-IX.

[0024] Fig.10 It is three-view drawing which shows the pressure member of 1st Embodiment.

[0025] Fig.11 It is three-view drawing which shows the centrifugal clutch unit of 1st Embodiment.

[0026] Fig.12 It is along Fig.11 Cross-sectional view along line XII-XII in FIG.

[0027] Fig.13 It is a perspective view showing the centrifugal clutch unit according to the first embodiment.

[0028] Fig.14 It is a schematic diagram showing a vehicle to which the power transmission device according to the first embodiment is applied.

[0029] Fig.15This is a cross-sectional view showing a state in which the weight member of the centrifugal clutch unit of the first embodiment starts to move from the inner diameter side position toward the outer diameter side position (a state in which inhibition by the inhibition unit is released).

[0030] Fig.16 This is a cross-sectional view showing a process in which the weight member of the centrifugal clutch unit according to the first embodiment moves from the inner diameter side position to the outer diameter side position (increasing cam operation).

[0031] Fig.17 This is a cross-sectional view showing a state in which the weight member of the centrifugal clutch unit according to the first embodiment has reached the outer diameter side position.

[0032] Fig.18 This is a schematic diagram showing a state in which the operation of the enlarging cam of the first embodiment is suppressed.

[0033] Fig.19 This is a schematic diagram showing a state in which the inhibition of the operation of the enlarging cam according to the first embodiment is released.

[0034] Fig. 20 It is a schematic diagram showing a state where the enlarging cam according to the first embodiment operates.

[0035] Fig.21 This is a schematic diagram showing a state in which the enlarging cam of the first embodiment has completed operation.

[0036] Fig. 22 It is a schematic diagram showing a state where the reverse torque limiter cam according to the first embodiment operates.

[0037] Fig.23 It is an external view showing a power transmission device according to a second embodiment.

[0038] Fig.24 It is along Fig.23 Cross-sectional view along line XXIV-XXIV.

[0039] Fig.25 It is an exploded perspective view showing a first clutch member and a second clutch member according to a second embodiment.

[0040] Fig.26 It is an exploded perspective view showing a first clutch member and a second clutch member according to a second embodiment.

[0041] Fig. 27 It is a three-view diagram showing a first clutch member according to a second embodiment.

[0042] Fig.28 This is a cross-sectional view showing a state in which the weight member of the centrifugal clutch unit of the second embodiment starts to move from the inner diameter side position toward the outer diameter side position (a state in which inhibition by the inhibition unit is released).

[0043] Fig.29 This is a cross-sectional view showing a process in which the weight member of the centrifugal clutch unit according to the second embodiment moves from the inner diameter side position to the outer diameter side position (increasing cam operation).

[0044] Fig.30 It is a cross-sectional view showing a state in which the weight member of the centrifugal clutch unit according to the second embodiment has reached the outer diameter side position.

[0045] Fig.31 This is a graph showing the relationship between the engine speed and each component.

[0046] Fig.32 It is a plan view of a clutch member according to a third embodiment. DETAILED DESCRIPTION

[0047] <First Embodiment>

[0048] Hereinafter, the embodiments of the present invention will be described in detail with reference to the accompanying drawings. Fig.14 As shown, the power transmission device K is provided in the vehicle and is used to arbitrarily transmit or cut off the driving force of the engine E to the driving wheel W side via the transmission M. The engine E is an example of a driving source. The driving wheel W is an example of a wheel. Figures 1 to 13 As shown, the power transmission device K comprises: a clutch housing 2, formed with an input gear 1 that rotates by the driving force of the engine E of the vehicle; an output shaft 3, connected to the transmission M; a clutch member 4; a pressure member 5; a plurality of driving side clutch plates 6 and a plurality of driven side clutch plates 7, assembled in a stacked state; and a centrifugal clutch unit 9, having a weight member 10. In addition, the reference symbol S in the figure represents a clutch spring. The clutch spring S acts on the pressure member 5 in the direction of approaching the clutch member 4 ( Figure 2 The input gear 1 is an example of an input member. The output shaft 3 is an example of an output member.

[0049] The input gear 1 is configured to be rotatable around the output shaft 3 when receiving a driving force (rotational force) transmitted from the engine E. The input gear 1 is connected to the clutch housing 2 by rivets or the like. The clutch housing 2 is formed as follows: Figure 2 , Figure 3 The clutch housing 2 is cylindrical in shape with the right end side opened. The clutch housing 2 is rotated together with the input gear 1 by the driving force of the engine E.

[0050] like Figure 4As shown in FIG. 1 , a plurality of cutouts 2a are formed in the entire circumference of the clutch housing 2. A plurality of drive-side clutch plates 6 are fitted into the cutouts 2a. That is, the clutch housing 2 holds a plurality of drive-side clutch plates 6. The drive-side clutch plates 6 are formed of a plate having a substantially annular shape. The drive-side clutch plates 6 are configured to rotate with the rotation of the clutch housing 2 and can be rotated in the axial direction (i.e., the output shaft 3) of the output shaft 3. Figure 2 , Figure 3 left and right directions in the image.

[0051] like Figure 2 As shown, the clutch member 4 is accommodated in the clutch housing 2. The clutch member 4 holds a plurality of driven side clutch plates 7 arranged alternately with the driving side clutch plates 6. The clutch member 4 is connected to the output shaft 3 capable of rotating the driving wheels W via the transmission M of the vehicle. Figure 5A and Figure 5B As shown, the clutch member 4 includes a first clutch member 4a and a second clutch member 4b. The first clutch member 4a is engaged with the second clutch member 4b.

[0052] like Figure 5A to Figure 7 As shown, the first clutch component 4a has an insertion hole 4ac formed in the center. The output shaft 3 is inserted into the insertion hole 4ac, and the gears formed mutually mesh and are connected in the rotation direction. That is, the first clutch component 4a is connected to the output shaft 3. The first clutch component 4a has a plurality of recesses A arranged along the circumferential direction. The recess A is formed on the outer peripheral surface of the first clutch component 4a. The first inclined surface 4aa constituting the cam for pressing contact assistance and the third inclined surface 4ab constituting the cam for reverse torque limiter are formed in the recess A. The first clutch component 4a has a boss portion 4ad. The boss portion 4ad is formed with an insertion hole for inserting the bolt B for connecting the first clutch component 4a and the fixing component 8. The first clutch component 4a has a plurality of through holes 4ag that penetrate in the axial direction of the output shaft 3 and are arranged along the circumferential direction. The through hole 4ag is located at a position radially outward of the insertion hole 4ac. The through hole 4ag is arranged between adjacent boss portions 4ad.

[0053] like Figure 8 As shown, the second clutch component 4b has an outer peripheral wall 4be formed in an annular shape and a flange portion 4bd extending radially outward from the outer peripheral wall 4be. A spline fitting portion 4bc is formed on the outer peripheral wall 4be. The driven side clutch plate 7 is mounted on the spline fitting portion 4bc by spline fitting. That is, the second clutch component 4b holds the driven clutch plate 7. The second clutch component 4b is configured to be able to move in the axial direction of the output shaft 3. As described later, the second clutch component 4b is configured so that when the suppression component D described later suppresses the generation of the second pressing contact force, the second clutch component 4b can be moved in a direction close to the pressure component 5 ( Figure 2 The second clutch member 4b has a plurality of convex portions T arranged in the circumferential direction and capable of being inserted into the concave portion A. Fig. 9 As shown in FIG. 1 , the convex portion T is formed with a second inclined surface 4ba constituting a press-contact assisting cam and a fourth inclined surface 4bb constituting a reverse torque limiter cam.

[0054] like Fig.10 As shown in FIG. 1 , the pressure member 5 is composed of a disk-shaped member having a flange portion 5a formed on the peripheral portion. The pressure member 5 is configured to be able to press the driving side clutch plate 6 and the driven side clutch plate 7 together with the clutch member 4. The pressure member 5 can transmit the driving force of the engine E to the driving wheel W by pressing the driving side clutch plate 6 and the driven side clutch plate 7 to contact each other. That is, the driving side clutch plate 6 and the driven side clutch plate 7 are arranged in a stacked state between the flange portion 5a of the pressure member 5 and the flange portion 4bd of the second clutch member 4b, and when the second clutch member 4b moves in a direction close to the pressure member 5 ( Figure 2 When the second clutch member 4b moves in the direction of the arrow DR2 in the figure), the driving side clutch plate 6 and the driven side clutch plate 7 are pressed against each other, so that the rotational force of the clutch housing 2 is transmitted to the output shaft 3 via the second clutch member 4b and the first clutch member 4a. On the other hand, when the second clutch member 4b moves in the direction away from the pressure member 5 ( Figure 2 When the clutch housing 2 moves in the direction of the arrow DR1 in the figure, the pressing contact force of the driving side clutch disc 6 and the driven side clutch disc 7 is released, the first clutch component 4a and the second clutch component 4b no longer follow the rotation of the clutch housing 2, and the rotational force of the clutch housing 2 is no longer transmitted to the output shaft 3.

[0055] In this way, when the driving side clutch disc 6 and the driven side clutch disc 7 are in a state of being pressed and contacted with each other, the rotational force input to the clutch housing 2 (i.e., the driving force of the engine E) is transmitted to the drive wheel side (i.e., the transmission M) via the output shaft 3. In addition, when the pressing and contact between the driving side clutch plate 6 and the driven side clutch plate 7 is released, the rotational force input to the clutch housing 2 is not transmitted to the output shaft 3.

[0056] When the first clutch member 4a and the second clutch member 4b are fitted with each other, the convex portion T is embedded in the concave portion A. In addition, when the first clutch member 4a and the second clutch member 4b are fitted with each other, the first inclined surface 4aa and the second inclined surface 4ba face each other to form a press contact auxiliary cam, and the third inclined surface 4ab and the fourth inclined surface 4bb face each other to form a reverse torque limiter cam. Figure 8 As shown, the convex portion T is formed with a coil spring D2 (see Figure 3 )'s receiving recess Ta.

[0057] The power transmission device K includes a pressing contact force increasing mechanism 20 (see Fig.18 ). The pressing contact force increasing mechanism 20 generates a second pressing contact force that increases the pressing contact force between the driving side clutch plate 6 and the driven side clutch plate 7 as the rotation speed of the engine E increases. The second pressing contact force is an example of a cam thrust. When the rotational force input to the input gear 1 is in a state where it can be transmitted to the output shaft 3, the pressing contact force increasing mechanism 20 generates a second pressing contact force that increases the pressing contact force between the driving side clutch plate 6 and the driven side clutch plate 7. The pressing contact force increasing mechanism 20 is configured to move a portion of the clutch component 4 (here, the second clutch component 4b) toward a direction approaching the pressure component 5 ( Figure 2 The pressing contact force increasing mechanism 20 is configured as a part of the clutch member 4 (here, the second clutch member 4b) while the axis 3C of the output shaft 3 (refer to Figure 5A ) is the center on the first circumference S1 (refer to Figure 5A ) rotates while moving toward the direction approaching the pressure member 5, thereby generating a second pressing contact force. The pressing contact force increasing mechanism 20 is Figure 2 The direction of the arrow DR2 ( Figure 2 The second pressing contact force is applied to the driving side clutch plate 6 and the driven side clutch plate 7 (in the left direction). The pressing contact force increasing mechanism 20 has a plurality of increasing cams 22. The increasing cam 22 generates the second pressing contact force. The increasing cam 22 is provided at a portion where the first clutch component 4a and the second clutch component 4b can contact each other. The increasing cam 22 is formed at the recess A of the first clutch component 4a and the convex portion T of the second clutch component 4b. The increasing cam 22 includes a first inclined surface 4aa formed at the recess A and a second inclined surface 4ba formed at the convex portion T and sliding relative to the first inclined surface 4aa. The second pressing contact force is generated by the operation of the increasing cam 22 (i.e., by the first inclined surface 4aa sliding relative to the second inclined surface 4ba). In the present embodiment, the pressing contact force increasing mechanism 20 has six increasing cams 22. In addition, the number of increasing cams 22 is not limited to six. The increasing cam 22 is an example of a first cam.

[0058] Here, if Fig. 20 As shown in FIG. 1 , when the rotation speed of the engine E increases and the rotational force input to the input gear 1 and the clutch housing 2 is in a state where it can be transmitted to the output shaft 3 via the first clutch member 4a and the second clutch member 4b (i.e., when the weight member 10 is located at the outer diameter side position), the second clutch member 4b is applied with a force. Fig. 20 As a result, the first inclined surface 4aa and the second inclined surface 4ba slide against each other to increase the operation of the cam 22, and a rotational force is generated in the second clutch member 4b. Fig. 20 The force in the direction of arrow c in FIG. 4 is applied. Furthermore, the second clutch member 4b is moved toward the direction approaching the pressure member 5 (i.e., the direction in which the flange portion 4bd of the second clutch member 4b approaches the flange portion 5a of the pressure member 5). Figure 2 and Figure 3 The clutch plate 6 moves in the direction of the arrow DR2 in FIG. 1 ), thereby generating a second pressing contact force that increases the pressing contact force between the driving side clutch plate 6 and the driven side clutch plate 7.

[0059] On the other hand, Fig. 22 As shown in FIG. 1 , when the rotation of the output shaft 3 exceeds the rotation speed of the input gear 1 and the clutch housing 2 and generates a reverse torque, the second clutch component 4b is applied Fig. 22 Thus, the third inclined surface 4ab and the fourth inclined surface 4bb slide against each other and the reverse torque limiter cam works, and the second clutch member 4b moves away from the pressure member 5 (i.e., Fig. 22 The clutch disc 6 moves in the direction of the arrow d in the figure to release the pressing contact force (herein, the second pressing contact force) between the driving side clutch disc 6 and the driven side clutch disc 7. This can avoid the power transmission device K or the power source (engine E side) from causing adverse conditions due to reverse torque.

[0060] like Figures 11 to 13 As shown, the centrifugal clutch unit 9 includes a weight member 10, which can be moved from an inner diameter side position (see Figure 2 ) to the outer diameter side (refer to Fig.17 ) moves. The centrifugal clutch unit 9 is arranged on the opening side of the clutch housing 2 ( Figure 2 , Figure 3 The centrifugal clutch unit 9 is arranged on the opposite side of the pressure member 5 across the driving side clutch plate 6 and the driven side clutch plate 7. Here, the centrifugal clutch unit 9 is arranged closer to the pressure member 5 than to the driving side clutch plate 6 and the driven side clutch plate 7. Figure 2 In the direction of arrow DR1 in FIG. 1 . When the weight component 10 is located at the outer diameter side position, the centrifugal clutch unit 9 causes the driving side clutch plate 6 and the driven side clutch plate 7 to press contact with each other, thereby forming a state in which the driving force of the engine E can be transmitted to the driving wheel W. The centrifugal clutch unit 9 is configured to apply a first pressing contact force to the driving side clutch plate 6 and the driven side clutch plate 7 as the weight component 10 moves from the inner diameter side position to the outer diameter side position. As the weight component 10 moves from the inner diameter side position to the outer diameter side position, the clutch component 4 (here, the second clutch component 4b) is moved in a direction ( Figure 2The centrifugal clutch unit 9 is configured to release the pressing contact force between the driving side clutch plate 6 and the driven side clutch plate 7 when the weight member 10 is located at the inner diameter side position, thereby cutting off the transmission of the driving force of the engine E to the driving wheel W. That is, the centrifugal clutch unit 9 is configured to release the first pressing contact force applied to the driving side clutch plate 6 and the driven side clutch plate 7 when the weight member 10 is located at the inner diameter side position, thereby cutting off the transmission of the driving force of the engine E to the wheel.

[0061] like Fig.12 As shown in FIG. 1 , the centrifugal clutch unit 9 includes: a plurality of weight components 10, a spring 11, a retainer 12, and a pressed component 13. The plurality of weight components 10 are arranged along the circumferential direction. The weight components 10 are accommodated in the annular retainer 12. The weight components 10 are made of metal. The weight components 10 are retained at the inner diameter side position (refer to FIG. 1 ) when no centrifugal force is applied. Figure 2 For example, when the rotation speed of the engine E is below a predetermined rotation speed, the weight component 10 is located at the inner diameter side position. The weight component 10 is configured to move radially outward against the force of the spring 11 by the centrifugal force applied thereto (i.e., when the rotation speed of the engine E is higher than the predetermined rotation speed) and reach the outer diameter side position (refer to Fig.17 ). The predetermined speed is higher than the idle speed.

[0062] like Fig.12 As shown, the centrifugal clutch unit 9 has a plurality of pressing cams 18, which move the clutch member 4 (here, the second clutch member 4b) toward the direction of approaching the pressure member 5 ( Figure 2 The pressing cam 18 moves in the direction of the arrow DR2 in the figure. The pressing cam 18 is an example of a second cam. The pressing cam 18 generates a first pressing contact force. The pressing cam 18 is provided at a portion where the weight component 10 and the pressed component 13 can contact each other. The pressing cam 18 is formed on the weight component 10 and the pressed component 13. The pressing cam 18 includes an inclined surface 10a formed at the front end (the front end on the radial outer side) of the weight component 10 and an inclined surface 13a formed on the pressed component 13. The inclined surface 10a and the inclined surface 13a of the pressing cam 18 are arranged to be slidable relative to the inclined surface 13a. The inclined surface 10a and the inclined surface 13a of the pressing cam 18 have an inclination angle θ1 (refer to the radial direction) with respect to the direction orthogonal to the axial direction of the output shaft 3. Fig.15 ) and the inclination angle θ2 of the first inclined surface 4aa relative to the radial direction (refer to Fig.18 ) and the inclination angle θ2 of the second inclined surface 4ba relative to the radial direction (refer to Fig.18) are different. The inclination angle θ1 is the angle formed by the straight line L1 extending in the radial direction and the inclined surface 10a and the inclined surface 13a. The inclination angle θ2 is the angle formed by the straight line L2 extending in the radial direction and the first inclined surface 4aa and the second inclined surface 4ba. The inclined surface 10a and the inclined surface 13a are examples of cam surfaces. The inclination angle θ2 of the first inclined surface 4aa with respect to the radial direction and the inclination angle θ2 of the second inclined surface 4ba with respect to the radial direction are greater than the inclination angle θ1 of the inclined surface 10a and the inclined surface 13a with respect to the radial direction.

[0063] When the weight member 10 moves from the inner diameter side position to the outer diameter side position due to the centrifugal force, the pressed member 13 moves to the Figure 2 The first clutch member 4b is moved in the direction of the arrow DR2 in FIG. 1 and presses the flange portion 4bd of the second clutch member 4b via the pressed ring 14. As a result, the driving side clutch plate 6 and the driven side clutch plate 7 are pressed and contacted. That is, the first pressing and contacting force is applied to the driving side clutch plate 6 and the driven side clutch plate 7. The driving force of the engine E is transmitted to the output shaft 3 by the driving side clutch plate 6 and the driven side clutch plate 7 being pressed and contacted with each other.

[0064] On the other hand, when the centrifugal force decreases, the weight member 10 moves from the outer diameter side position toward the inner diameter side position by the urging force of the spring 11, and the second clutch member 4b is moved by the coil spring D2 (see Figure 3 ) Figure 3 The clutch plate 6 moves in the direction of the arrow DR1 in FIG. 1 , and the pressing contact force between the driving side clutch plate 6 and the driven side clutch plate 7 is released. The pressing contact force between the driving side clutch plate 6 and the driven side clutch plate 7 is released, and the transmission of the driving force of the engine E to the output shaft 3 is cut off.

[0065] The power transmission device K includes a suppressing member D (see Figure 3 and Figure 6), when the rotation speed of the engine E is lower than a predetermined rotation speed (for example, when the weight member 10 is located at the inner diameter side position), the suppression member D suppresses the driving side clutch plate 6 and the driven side clutch plate 7 from being pressed into contact with each other, thereby suppressing the transmission of the driving force of the engine E (for example, a part of the driving force of the engine E) to the driving wheel W. The suppression member D suppresses the generation of the second pressing contact force by the pressing contact force increasing mechanism 20 when the rotation speed of the engine E is lower than a predetermined rotation speed. The suppression member D suppresses the operation of the increasing cam 22 when the rotation speed of the engine E is lower than a predetermined rotation speed, thereby suppressing the generation of the second pressing contact force. The suppression member D suppresses the generation of the second pressing contact force in at least a part of the range of rotation speeds where the rotation speed of the engine E is lower than the idle rotation speed. In the present embodiment, the suppression member D suppresses the generation of the second pressing contact force in the range of all rotation speeds where the rotation speed of the engine E is lower than the idle rotation speed. The suppression member D allows the pressing contact force increasing mechanism 20 to generate the second pressing contact force when the rotation speed of the engine E is higher than a predetermined rotation speed. The suppression member D allows the cam 22 to be operated when the engine E rotates at a higher speed than a predetermined speed, thereby allowing the second pressing contact force to be generated. The suppression member D includes a step portion D1 (see FIG. 1 ) that engages with the convex portion T of the second clutch member 4b. Figure 6 ) and coil spring D2 (see Figure 3 ). The suppression member D is provided at a portion where the first clutch member 4a and the second clutch member 4b can contact each other.

[0066] like Figure 6 and Figure 7 As shown, the step portion D1 is provided at a portion where the first clutch member 4a and the second clutch member 4b can contact each other. The step portion D1 is formed at a predetermined portion of the recess A of the first clutch member 4a. When the protrusion T of the second clutch member 4b is engaged with the step portion D1, the sliding between the first inclined surface 4aa and the second inclined surface 4ba is suppressed. By releasing the engagement between the protrusion T and the step portion D1, the suppression of the sliding between the first inclined surface 4aa and the second inclined surface 4ba is released.

[0067] like Figure 3 As shown in FIG. 1 , the coil spring D2 is accommodated in the accommodation recess Ta formed in the convex portion T of the second clutch member 4b. One end of the coil spring D2 is abutted against and assembled to the support ring 15 fixed to the first clutch member 4a, and is directed toward the second clutch member 4b via the convex portion T. Figure 3 That is, the coil spring 16 applies force to the second clutch member 4b as a part of the clutch member 4 in a direction away from the pressure member 5. The direction in which the coil spring D2 applies force to the second clutch member 4b ( Figure 3 The direction of the arrow DR1 in the figure) and the direction of the first pressing contact force applied by the weight member 10 to the driving side clutch plate 6 and the driven side clutch plate 7 ( Figure 3 The axis of the coil spring D2 is parallel to the axis of the output shaft 3. Figure 5A As shown, the coil spring D2 is arranged between the output shaft 3 and the outer peripheral wall 4be of the second clutch member 4b in the radial direction orthogonal to the axial direction of the output shaft 3. The coil spring D2 is arranged between the adjacent through holes 4ag in the circumferential direction. When the first pressing contact force is less than the acting force of the coil spring D2, the sliding between the first inclined surface 4aa and the second inclined surface 4ba is suppressed. By making the first pressing contact force greater than the acting force of the coil spring D2, the suppression of the sliding between the first inclined surface 4aa and the second inclined surface 4ba is released.

[0068] like Fig.18 As shown, the suppression component D suppresses (for example, limits) the operation of the increasing cam 22 when the weight component 10 is located at the inner diameter side position (that is, when the rotation speed of the engine E is below a predetermined rotation speed). When the weight component 10 is located at the inner diameter side position, the suppression component D engages (contacts) with a predetermined portion F of the convex portion T to suppress (for example, limit) the sliding of the first inclined surface 4aa and the second inclined surface 4ba. That is, the suppression component D suppresses the generation of the second pressing contact force. In addition, it is configured so that when the suppression component D suppresses the generation of the second pressing contact force, a part of the clutch component (here, the second clutch component 4b) can be moved in a direction close to the pressure component 5 ( Figure 2 Therefore, if Fig.19 As shown, as the weight member 10 moves from the inner diameter side position to the outer diameter side position, the engagement between the suppression member D and the predetermined portion F of the convex portion T is released (that is, the predetermined portion F of the convex portion T is separated from the suppression member D). Fig. 20 As shown, in a state where the engagement between the suppression component D and the predetermined position F of the convex portion T is released, the suppression component D allows the first inclined surface 4aa and the second inclined surface 4ba to slide. The suppression component D releases the inhibition of the operation of the increasing cam 22 by moving the weight component 10 from the inner diameter side position to the outer diameter side position to enable the increasing cam 22 to operate. That is, the suppression component D releases the inhibition of the generation of the second pressing contact force during the movement of the weight component 10 from the inner diameter side position to the outer diameter side position. At this time, for example, the suppression component D can also release the inhibition of the generation of the second pressing contact force at a rotation speed at which the driving side clutch plate 6 and the driven side clutch plate 7 are pressed and contacted and the driving force of the engine E starts to be transmitted to the driving wheel W. As a result, in a state where the driving side clutch plate 6 and the driven side clutch plate 7 are pressed and contacted with each other (i.e., the connection of the centrifugal clutch unit 9 is started) and the driving force of the engine E is transmitted to the driving wheel W, the pressing contact force between the driving side clutch plate 6 and the driven side clutch plate 7 can be effectively increased.

[0069] like Fig.18 As shown, when the weight component 10 is located at the inner diameter side position (i.e., when the rotation speed of the engine E is below the predetermined rotation speed), even if a drag torque is generated between the driving side clutch plate 6 and the driven side clutch plate 7, the step portion D1 engages (contacts) with the predetermined position F of the convex portion T, thereby suppressing the increase cam 22 from accidentally operating. In addition, when the weight component 10 is located at the inner diameter side position (i.e., when the rotation speed of the engine E is equal to or less than the predetermined rotation speed), even if a drag torque is generated between the driving side clutch plate 6 and the driven side clutch plate 7, the coil spring D2 applies force to the second clutch component 4b in a direction away from the pressure component 5, thereby suppressing the increase cam 22 from accidentally operating. In addition, as Fig.15 As shown in FIG. 1 , when the speed of the engine E increases, the weight component 10 starts to move from the inner diameter side position to the outer diameter side position, and when the first pressing contact force exceeds the set load of the coil spring D2, the second clutch component 4b moves to the outer diameter side position. Fig.15 The second clutch member 4b moves in the direction of the arrow DR2 (the direction in which the flange 4bd of the second clutch member 4b approaches the flange 5a of the pressure member 5). Fig.19 As shown, the convex portion T is Fig.19 The step portion D1 moves in the direction of the arrow DR2, so that the engagement between the step portion D1 and the predetermined portion F of the convex portion T is released (that is, the predetermined portion F of the convex portion T is separated from the step portion D1), and the enlarging cam 22 can be operated.

[0070] And, if Fig.16 As shown, during the movement of the weight component 10 from the inner diameter side position to the outer diameter side position, as shown in FIG. Fig. 20 As shown in FIG. 1 , when the first inclined surface 4aa and the second inclined surface 4ba slide against each other and the amplifying cam 22 operates, in addition to the first pressing contact force of the centrifugal clutch unit 9, a second pressing contact force is generated to increase the pressing contact force between the driving side clutch plate 6 and the driven side clutch plate 7. Fig.17 As shown, when the weight component 10 reaches the outer diameter side position, as shown in Fig.21 As shown, the predetermined portion F of the convex portion T abuts against the inner peripheral edge of the concave portion A, and the operation of the enlarging cam 22 stops.

[0071] <Second Embodiment>

[0072] like Figure 23~Figure 30 As shown, the power transmission device K2 includes: a clutch housing 2; an output shaft 3; a clutch member 204; a pressure member 205; a plurality of driving side clutch plates 6 and a plurality of driven side clutch plates 7 assembled in a stacked state; and a centrifugal clutch unit 9 having a weight member 10. In addition, the same reference numerals are attached to the same components as those in the first embodiment, and their detailed description is omitted.

[0073] The power transmission device K2 includes a clutch spring S. The clutch spring S acts on the pressure member 205 in a direction close to the clutch member 204 ( Fig.24 Apply force in the direction of arrow DR2.

[0074] like Fig.26 As shown, the pressure member 5 is formed with a sixth inclined surface 5b and an eighth inclined surface 5c. The pressure member 5 has a plurality of engaging teeth 5e for holding the driven clutch plate 7. The plurality of engaging teeth 5e are arranged along the circumferential direction. The engaging teeth 5e are located radially inward of the flange portion 5a. The engaging teeth 5e are located radially outward of the sixth inclined surface 5b and the eighth inclined surface 5c. The pressure member 5 is configured to be able to approach or move away from the clutch member 4. The pressure member 5 is configured to be able to press the driving side clutch plate 6 and the driven side clutch plate 7.

[0075] like Fig. 27 As shown in FIG. 1 , the first clutch member 204a is formed with a fifth inclined surface 4ae and a seventh inclined surface 4af. When the first clutch member 204a and the pressure member 205 are assembled, the fifth inclined surface 4ae and the sixth inclined surface 5b face each other to form a reverse torque limiter cam, and the seventh inclined surface 4af and the eighth inclined surface 5c face each other to form a press contact auxiliary cam. When the speed of the engine E becomes higher than a predetermined speed, the seventh inclined surface 4af and the eighth inclined surface 5c slide against each other. As a result, the pressure member 205 moves toward Fig.24 The driving side clutch plate 6 and the driven side clutch plate 7 are pressed and contacted. That is, the third pressing contact force is generated between the driving side clutch plate 6 and the driven side clutch plate 7. On the other hand, the pressure member 5 is moved to the driving side clutch plate 6 and the driven side clutch plate 7 by the mutual sliding of the fifth inclined surface 4ae and the sixth inclined surface 5b. Fig.24 As a result, the pressing contact force (here, the third pressing contact force) between the driving side clutch plate 6 and the driven side clutch plate 7 is released.

[0076] like Fig.24 As shown in FIG. 1 , the centrifugal clutch unit 9 is arranged on the opposite side of the pressure member 205 across the driving side clutch plate 6 and the driven side clutch plate 7. Here, the centrifugal clutch unit 9 is arranged closer to the pressure member 205 than to the driving side clutch plate 6 and the driven side clutch plate 7. Fig.24 The weight member 10 of the centrifugal clutch device 9 is configured to be able to be moved from the inner diameter side position (refer to Fig.24 ) to the outer diameter side (refer to Fig.30 ) moves. As the weight member 10 moves from the inner diameter side position to the outer diameter side position, the weight member 10 moves the clutch member 4 (here, the second clutch member 4b) toward the direction of approaching the pressure member 5 ( Fig.24Apply force in the direction of arrow DR1.

[0077] The pressing contact force increasing mechanism 20 applies pressure to the driving side clutch plate 6 and the driven side clutch plate 7. Fig.24 A second pressing contact force is applied in the direction of arrow DR1.

[0078] The power transmission device K2 includes an auxiliary cam mechanism 30. When the first clutch member 204a rotates relative to the pressure member 205, the auxiliary cam mechanism 30 generates a third pressing contact force that increases the pressing contact force between the driving side clutch plate 6 and the driven side clutch plate 7. The auxiliary cam mechanism 30 applies a third pressing contact force to the driving side clutch plate 6 and the driven side clutch plate 7. Fig.24 The third pressing contact force is applied in the direction of the arrow DR2 in FIG. That is, the direction in which the second pressing contact force is applied ( Fig.24 The direction of the arrow DR1 in the figure) and the direction in which the third pressing contact force is applied ( Fig.24 The auxiliary cam mechanism 30 has a plurality of auxiliary cams 32. The auxiliary cam 32 includes a seventh inclined surface 4af and an eighth inclined surface 5c. In the present embodiment, the auxiliary cam mechanism 30 has three auxiliary cams 32. The number of auxiliary cams 32 is not limited to three. In the present embodiment, the number of increasing cams 22 is six, and the number of increasing cams 22 is greater than the number of auxiliary cams 32. In addition, the number of increasing cams 22 may be the same as the number of auxiliary cams 32.

[0079] like Fig.31 As shown by the arrow ER1 in FIG. 1 , the pressing contact force increasing mechanism 20 operates when the speed of the engine E is in the range of R5 to R9. The pressing contact force increasing mechanism 20 starts to generate the second pressing contact force when the speed of the engine E is R5, and stops generating the second pressing contact force when the speed of the engine E is R9. Fig.31 As shown by arrow ER2 in FIG. 1 , the auxiliary cam mechanism 30 operates when the speed of the engine E is in the range of R7 to R10. The auxiliary cam mechanism 30 starts to generate the third pressing contact force when the speed of the engine E is R7, and stops generating the third pressing contact force when the speed of the engine E is R10. Fig.31 As shown by the arrow ER3 in the figure, the weight component 10 operates when the speed of the engine E is in the range of R2 to R8. The weight component 10 starts to move from the inner diameter side position to the outer diameter side position when the speed of the engine E is R2, and ends the movement and is located at the outer diameter side position when the speed of the engine E is R8. Fig.31As shown by the arrow ER4 in , the suppression component D works when the speed range of the engine E is R1~R3. That is, the suppression component D suppresses the second pressing contact force generated by the pressing contact force increasing mechanism 20 when the speed range of the engine E is R1~R3. The suppression component D starts to suppress the generation of the second pressing contact force when the speed of the engine E is R1, and releases the suppression of the generation of the second pressing contact force when the speed of the engine E is R3. In addition, the suppression component D can also release the suppression of the generation of the second pressing contact force at the speed R4 at which the connection between the driving side clutch plate 6 and the driven side clutch plate 7 is started. Fig.31 In the figure, the rotation speed RI of the engine E represents the idle speed, and the rotation speed RMAX of the engine E represents the maximum speed. In addition, when the rotation speed of the engine E is R4, the connection between the driving side clutch plate 6 and the driven side clutch plate 7 begins. When the rotation speed of the engine E is R6, the driving side clutch plate 6 and the driven side clutch plate 7 are completely connected. When the rotation speed of the engine E is R4, the driving force of the engine E begins to be transmitted to the drive wheel W. In addition, the range of each rotation speed mentioned above is not limited to the range shown by the arrow ER1 to the arrow ER4.

[0080] like Fig.31 As shown, the rotation speed (R7) of the engine E at which the auxiliary cam mechanism 30 starts to operate is different from the rotation speed (R5) of the engine E at which the pressing contact force increasing mechanism 20 starts to operate. The rotation speed (R5) of the engine E at which the pressing contact force increasing mechanism 20 starts to operate is lower than the rotation speed (R7) of the engine E at which the auxiliary cam mechanism 30 starts to operate. The rotation speed (R7) of the engine E at which the auxiliary cam mechanism 30 starts to operate is different from the rotation speed (R9) of the engine E at which the pressing contact force increasing mechanism 20 ends to operate. The rotation speed (R7) of the engine E at which the auxiliary cam mechanism 30 starts to operate is lower than the rotation speed (R9) of the engine E at which the pressing contact force increasing mechanism 20 ends to operate. The rotation speed (R7) of the engine E at which the auxiliary cam mechanism 30 starts to operate is lower than the rotation speed (R8) of the engine E at which the movement of the weight member 10 to the outer diameter side position ends to operate. The range (R7 to R10) of the rotation speed of the engine E at which the auxiliary cam mechanism 30 operates is different from the range (R5 to R9) of the rotation speed of the engine E at which the pressing contact force increasing mechanism 20 operates. The range ( R7 to R10 ) of the rotation speed of the engine E in which the assist cam mechanism 30 operates is wider than the range ( R5 to R9 ) of the rotation speed of the engine E in which the pressing contact force increasing mechanism 20 operates.

[0081] Here, when the rotation speed of the engine E increases and the rotational force input to the input gear 1 and the clutch housing 2 is in a state where it can be transmitted to the output shaft 3 via the first clutch member 204a and the second clutch member 4b (i.e., the weight member 10 is located at the outer diameter side), the first pressing contact force is applied to the driving side clutch plate 6 and the driven side clutch plate 7, and the first inclined surface 4aa and the second inclined surface 4ba slide against each other, and the seventh inclined surface 4af and the eighth inclined surface 5c slide against each other. As a result, the second clutch member 4b and the pressure member 205 move in directions approaching each other, respectively, and the second pressing contact force and the third pressing contact force that increase the pressing contact force between the driving side clutch plate 6 and the driven side clutch plate 7 are generated. That is, when the rotation speed of the engine E reaches a predetermined rotation speed, the pressing contact force increasing mechanism 20 and the auxiliary cam mechanism 30 operate, and the second pressing contact force and the third pressing contact force are applied to the driving side clutch plate 6 and the driven side clutch plate 7. At this time, the first pressing contact force, the second pressing contact force and the third pressing contact force are applied to the driving side clutch plate 6 and the driven side clutch plate 7. The first pressing contact force and the second pressing contact force are applied in the direction from the centrifugal clutch member 9 toward the pressure member 205 ( Fig.24 The third pressing contact force is applied in the direction from the pressure member 205 toward the centrifugal clutch member 9 ( Fig.24 In the direction of arrow DR2 in FIG. 1 , the first pressing contact force and the second pressing contact force are applied. In addition, when the rotation speed of the engine E is a rotation speed at which the driving force of the engine E cannot be transmitted to the driving wheel W, the total value of the first pressing contact force and the second pressing contact force is greater than the third pressing contact force. In addition, regardless of whether the driving side clutch plate 6 and the driven side clutch plate 7 are divided into multiple groups, the relationship that the total value of the first pressing contact force and the second pressing contact force is greater than the third pressing contact force holds true. For example, when the driving side clutch plate 6 and the driven side clutch plate 7 are divided into multiple groups, in one of the groups, at least a portion of the driving side clutch plate 6 and the driven side clutch plate 7 are in contact with each other, but in other groups, the driving side clutch plate 6 and the driven side clutch plate are not in contact, and the driving force of the engine E is not transmitted to the driving wheel W, the above relationship also holds true. In addition, the rotation speed of the engine E is a rotation speed at which the driving force of the engine E cannot be transmitted to the driving wheel W, which means that the driving force of the engine E is not transmitted to the driving wheel W in a state where the driving side clutch plate 6 is not in contact with the driven side clutch plate 7, or at least a part of the driving side clutch plate 6 is in contact with at least a part of the driven side clutch plate 7. When the weight member 10 is located at the outer diameter side position, the total value of the first pressing contact force and the second pressing contact force and the total value of the third pressing contact force and the set load of the clutch spring S are the same.

[0082] On the other hand, when the rotation of the output shaft 3 exceeds the rotation speed of the input gear 1 and the clutch housing 2 and generates reverse torque, the third inclined surface 4ab and the fourth inclined surface 4bb slide against each other and the fifth inclined surface 4ae and the sixth inclined surface 5b slide against each other. As a result, the second clutch member 4b and the pressure member 205 move in the direction of separation from each other, and the pressing contact force (i.e., the second pressing contact force and the third pressing contact force) between the driving side clutch plate 6 and the driven side clutch plate 7 is released. At this time, the first pressing contact force is applied to the driving side clutch plate 6 and the driven side clutch plate 7.

[0083] As described above, the power transmission device K2 of the present embodiment includes, in addition to the centrifugal clutch unit 9 for applying the first pressing contact force and the pressing contact force increasing mechanism 20 for generating the second pressing contact force, the auxiliary cam mechanism 30, which generates the third pressing contact force for increasing the pressing contact force between the driving side clutch plate 6 and the driven side clutch plate 7 when the clutch member 4 rotates relative to the pressure member 5. According to the above mode, the third pressing contact force is generated on the driving side clutch plate 6 and the driven side clutch plate 7 in addition to the first pressing contact force and the second pressing contact force according to the operating state of the vehicle, so that the pressing contact force of the driving side clutch plate 6 and the driven side clutch plate 7 can be maximized. As a result, the driving force of the engine E can be transmitted to the driving wheel W more efficiently.

[0084] In the power transmission device K2 of the present embodiment, when the rotation speed of the engine E reaches a predetermined rotation speed, the pressing contact force increasing mechanism 20 and the auxiliary cam mechanism 30 operate to apply the second pressing contact force and the third pressing contact force to the driving side clutch plate 6 and the driven side clutch plate 7. According to the above method, when the rotation speed of the engine E reaches a predetermined rotation speed, the pressing contact force of the driving side clutch plate 6 and the driven side clutch plate 7 can be maximized.

[0085] In the power transmission device K2 of the present embodiment, when the rotation speed of the engine E is a rotation speed at which the driving force of the engine E cannot be transmitted to the drive wheel W, the total value of the first pressing contact force and the second pressing contact force is greater than the third pressing contact force. According to the above method, even when the driving force of the engine E is a rotation speed at which it cannot be transmitted to the drive wheel W, the pressing contact of the driving side clutch plate 6 and the driven side clutch plate 7 can be started.

[0086] In the power transmission device K2 of the present embodiment, the number of the enlarged cams 22 may be equal to or greater than the number of the auxiliary cams 32. According to the above aspect, the enlarged cams 22 can generate a sufficient second pressing contact force.

[0087] In the power transmission device K2 of the present embodiment, the number of the enlarged cams 22 may be greater than the number of the auxiliary cams 32. According to the above aspect, the enlarged cams 22 can generate a sufficient second pressing contact force.

[0088] In the power transmission device K2 of the present embodiment, the direction in which the pressing contact force increasing mechanism 20 applies the second pressing contact force to the driving side clutch plate 6 and the driven side clutch plate 7 is opposite to the direction in which the auxiliary cam mechanism 30 applies the third pressing contact force to the driving side clutch plate 6 and the driven side clutch plate 7. According to the above method, the driving side clutch plate 6 and the driven side clutch plate 7 can be pressed and contacted from both sides, so the driving side clutch plate 6 and the driven side clutch plate 7 can be pressed and contacted reliably and more firmly.

[0089] In the power transmission device K2 of the present embodiment, when the weight member 10 is located at the outer diameter side position, the total value of the first pressing contact force and the second pressing contact force is equal to the total value of the third pressing contact force and the set load of the clutch spring S. According to the above method, the driving side clutch plate 6 and the driven side clutch plate 7 can be pressed and contacted in a balanced manner from both sides.

[0090] In the power transmission device K2 of the present embodiment, the first pressing contact force and the second pressing contact force are applied in the direction of the pressure member 5 in front of the centrifugal clutch unit 9, and the third pressing contact force is applied in the direction from the pressure member 5 toward the centrifugal clutch unit 9. According to the above-mentioned method, the driving side clutch plate 6 and the driven side clutch plate 7 can be pressed and contacted from both sides, so the driving side clutch plate 6 and the driven side clutch plate 7 can be pressed and contacted reliably and more firmly.

[0091] In the power transmission device K2 of the present embodiment, the rotation speed of the engine E at which the pressing contact force increasing mechanism 20 starts to operate may be different from the rotation speed of the engine E at which the auxiliary cam mechanism 30 starts to operate. According to the above method, the second pressing contact force and the third pressing contact force can be applied to the driving side clutch plate 6 and the driven side clutch plate 7 at the optimal rotation speed of the engine E.

[0092] In the power transmission device K2 of the present embodiment, the rotation speed of the engine E at which the pressing contact force increasing mechanism 20 starts to operate may be lower than the rotation speed of the engine E at which the auxiliary cam mechanism 30 starts to operate. According to the above embodiment, the second pressing contact force can be applied to the driving side clutch plate 6 and the driven side clutch plate 7 at the optimal rotation speed of the engine E.

[0093] In the power transmission device K2 of the present embodiment, the range of the rotation speed of the engine E in which the pressing contact force increasing mechanism 20 operates may be different from the range of the rotation speed of the engine E in which the auxiliary cam mechanism 30 operates. According to the above method, the second pressing contact force and the third pressing contact force can be applied to the driving side clutch plate 6 and the driven side clutch plate 7 at the optimal rotation speed of the engine E.

[0094] In the power transmission device K2 of the present embodiment, the range of the rotation speed of the engine E in which the auxiliary cam mechanism 30 operates may be larger than the range of the rotation speed of the engine E in which the pressing contact force increasing mechanism 20 operates. According to the above-mentioned embodiment, the third pressing contact force can be applied to the driving side clutch plate 6 and the driven side clutch plate 7 at the optimal rotation speed of the engine E.

[0095] In the power transmission device K2 of the present embodiment, the rotation speed of the engine E at which the auxiliary cam mechanism 30 starts to operate is different from the rotation speed of the engine E at which the operation of the pressing contact force increasing mechanism 20 ends. According to the above-mentioned method, the second pressing contact force and the third pressing contact force can be applied to the driving side clutch plate 6 and the driven side clutch plate 7 at the optimal rotation speed of the engine E.

[0096] In the power transmission device K2 of the present embodiment, the rotation speed of the engine E at which the auxiliary cam mechanism 30 starts to operate is lower than the rotation speed of the driving source at which the operation of the pressing contact force increasing mechanism 20 ends. According to the above embodiment, the third pressing contact force can be applied to the driving side clutch plate 6 and the driven side clutch plate 7 at the optimal rotation speed of the engine E.

[0097] In the power transmission device K2 of the present embodiment, the rotation speed of the engine E at which the auxiliary cam mechanism 30 starts to operate is lower than the rotation speed of the engine E at which the weight member 10 finishes moving to the outer diameter side position. According to the above embodiment, the third pressing contact force can be applied to the driving side clutch plate 6 and the driven side clutch plate 7 at the optimal rotation speed of the engine E.

[0098] <Third Embodiment>

[0099] Fig.32 FIG. 3 is a top view of the clutch component 304 of the third embodiment. Fig.32 As shown, the clutch member 304 includes a first clutch member 304a, a second clutch member 304b, and a torsion spring D3. The first clutch member 304a is fitted into the second clutch member 304b. The torsion spring D3 is an example of the restraining member D. In the third embodiment, the step portion D1 is an example of another restraining member.

[0100] like Fig.32As shown, the first clutch member 304a includes a housing portion 305 for housing the torsion spring D3 and a retaining portion 306 formed in the housing portion 305 and retaining the torsion spring D3. The retaining portion 306 is formed in a cylindrical shape and extends in the axial direction of the output shaft 3.

[0101] like Fig.32 As shown, the torsion spring D3 is accommodated in the accommodation portion 305 formed in the first clutch member 304a. One end of the torsion spring D3 can be assembled to the side wall of the accommodation portion 305 in abutment, and the other end of the torsion spring D3 is inserted into the insertion hole 307 formed in the second clutch member 304b and abuts against the outer peripheral wall 4be. The torsion spring D3 applies force to a part of the clutch member (here, the second clutch member 304b) in the second circumferential direction S2, which is the opposite direction of the first circumferential direction S1. The torsion spring D3 is arranged between the first clutch member 304a and the second clutch member 304b. The torsion spring D3 is arranged at a position radially outward of the output shaft 3 and radially inward of the outer peripheral edge 4bf of the outer peripheral wall 4be of the second clutch member 304b in the radial direction, which is a direction orthogonal to the axial direction of the output shaft 3. The torsion spring D3 is arranged between adjacent through holes 4ag in the circumferential direction. When the rotation torque in the first circumferential direction S1 generated on the second clutch member 304b by the first pressing contact force is less than the acting force of the torsion spring D3, the sliding between the first inclined surface 4aa and the second inclined surface 4ba is suppressed. That is, the torsion spring D3 limits the generation of the second pressing contact force by the pressing contact force increasing mechanism 20. By making the above-mentioned rotation torque greater than the acting force of the torsion spring D3, the inhibition of the sliding between the first inclined surface 4aa and the second inclined surface 4ba is released. That is, the torsion spring D3 allows the pressing contact force increasing mechanism 20 to generate the second pressing contact force.

[0102] The preferred embodiments of the present invention have been described above, but the above embodiments are merely examples, and the present invention can be implemented in various other forms.

[0103] In each of the above-mentioned embodiments, the engine E is used as the driving source, but the driving source is not limited to the engine E, and may be, for example, an electric motor or the like.

[0104] In the above embodiment, the first clutch member 4a has the recessed portion A and the second clutch member 4b has the convex portion T, but the present invention is not limited thereto. For example, the first clutch member 4a may have the convex portion T and the second clutch member 4b may have the recessed portion A.

[0105] In each of the above-mentioned embodiments, in the axial direction of the output shaft 3, the clutch member 4 is arranged between the centrifugal clutch unit 9 having the weight member 10 and the pressure member 5, and the weight member 10 moves from the inner diameter side position to the outer diameter side position, and the clutch member 4 (here, the second clutch member 4b) is moved in the direction approaching the pressure member 5 (for example, Figure 2 For example, in the axial direction of the output shaft 3, the pressure member 5 may be arranged between the centrifugal clutch unit 9 having the weight member 10 and the clutch member 4, and the weight member 10 may apply force to the pressure member 5 in a direction close to the clutch member 4 as it moves from the inner diameter side position to the outer diameter side position.

[0106] In the first embodiment described above, the suppression member D includes the step portion D1 and the coil spring D2 . However, if only one of them is included, the generation of the second pressing contact force by the pressing contact force increasing mechanism 20 can be suppressed.

[0107] In the third embodiment described above, the suppression member D includes the step portion D1 and the torsion spring D3 , but if only one of them is included, the generation of the second pressing contact force by the pressing contact force increasing mechanism 20 can be suppressed.

[0108] The power transmission device of the present invention can be applied to various multi-plate clutch type power transmission devices such as automobiles, three-wheeled or four-wheeled all-terrain vehicles, or general-purpose machines in addition to motorcycles.

[0109] Description of Reference Numerals

[0110] 1Input gear (input component)

[0111] 2 Clutch housing

[0112] 3 Output shaft (output component)

[0113] 4 Clutch components

[0114] 4a First clutch component

[0115] 4aa First inclined surface

[0116] 4ab third inclined surface

[0117] 4ae Fifth inclined surface

[0118] 4af Seventh inclined plane

[0119] 4ag through hole

[0120] 4b Second clutch component

[0121] 4ba Second inclined surface

[0122] 4bb fourth inclined surface

[0123] 4bc spline fitting part

[0124] 4bd flange

[0125] 4be outer wall

[0126] 5Pressure parts

[0127] 5a Flange

[0128] 5b Sixth inclined surface

[0129] 5c Eighth inclined surface

[0130] 5e Mosaic Teeth

[0131] 6 Drive side clutch plate

[0132] 7 Driven side clutch plate

[0133] 9 Centrifugal Clutch Unit

[0134] 10. Counterweight components

[0135] 10a Inclined surface

[0136] 13 Pressed parts

[0137] 13a Inclined surface

[0138] 18 Pressing cam (second cam)

[0139] 20 Pressing contact force increasing mechanism

[0140] 22 Enlargement cam (first cam)

[0141] 30 auxiliary cam mechanism

[0142] 32 auxiliary cam

[0143] A concave part

[0144] D Suppression components

[0145] D1 step (suppression part)

[0146] D2 coil spring (restraint component)

[0147] D3 torsion spring (restraint component)

[0148] E-engine

[0149] K Power Transmission Device

[0150] S Clutch Spring

[0151] T convex part

[0152] Ta receiving recess

[0153] W driving wheel.

Claims

1. A power transmission device comprising: a clutch member housed in a clutch housing, the clutch housing rotating together with an input member rotated by a driving force of a driving source and holding a plurality of driving-side clutch plates, the clutch member being connected to an output member capable of rotating a wheel, and the clutch member holding a plurality of driven-side clutch plates alternately arranged with the driving-side clutch plates; a pressure member capable of pressing the driving side clutch plate and the driven side clutch plate together with the clutch member; The centrifugal clutch unit comprises a weight component, wherein the weight component can be moved from an inner diameter side position to an outer diameter side position by the centrifugal force generated by the rotation of the clutch housing, and the centrifugal clutch unit applies a first pressing contact force to the driving side clutch plate and the driven side clutch plate as the weight component moves from the inner diameter side position to the outer diameter side position. When the weight component is located at the outer diameter side position, the centrifugal clutch unit causes the driving side clutch plate and the driven side clutch plate to be pressed into contact with each other so as to be in a state capable of transmitting the driving force of the driving source to the wheel, and when the weight component is located at the inner diameter side position, the centrifugal clutch unit releases the first pressing contact force applied to the driving side clutch plate and the driven side clutch plate, thereby being able to cut off the transmission of the driving force of the driving source to the wheel; a pressing contact force increasing mechanism for generating a second pressing contact force that increases the pressing contact force between the driving side clutch plate and the driven side clutch plate as the rotation speed of the driving source increases; and The assist cam mechanism generates a third pressing contact force that increases the pressing contact force between the driving side clutch plate and the driven side clutch plate when the clutch member rotates relative to the pressure member.

2. The power transmission device according to claim 1, wherein: When the rotation speed of the driving source reaches a predetermined rotation speed, the pressing contact force increasing mechanism and the auxiliary cam mechanism operate to apply the second pressing contact force and the third pressing contact force to the driving side clutch plate and the driven side clutch plate.

3. The power transmission device according to claim 1 or 2, wherein: When the rotation speed of the driving source is a rotation speed at which the driving force of the driving source cannot be transmitted to the wheel, the total value of the first pressing contact force and the second pressing contact force is larger than the third pressing contact force.

4. The power transmission device according to claim 1, wherein: The pressing contact force increasing mechanism has a plurality of increasing cams that generate the second pressing contact force. The auxiliary cam mechanism has a plurality of auxiliary cams that generate the third pressing contact force. The number of the enlarging cams is the same as or greater than the number of the auxiliary cams.

5. The power transmission device according to claim 4, wherein: The number of the enlarging cams is greater than the number of the auxiliary cams.

6. The power transmission device according to claim 1, wherein: The direction in which the pressing contact force increasing mechanism applies the second pressing contact force to the driving side clutch plate and the driven side clutch plate and the direction in which the auxiliary cam mechanism applies the third pressing contact force to the driving side clutch plate and the driven side clutch plate are opposite to each other.

7. The power transmission device according to claim 6, wherein: The power transmission device includes a clutch spring, the clutch spring urging the pressure member in a direction approaching the clutch member. When the weight member is located at the outer diameter side position, a total value of the first pressing contact force and the second pressing contact force is equal to a total value of the third pressing contact force and a set load of the clutch spring.

8. The power transmission device according to claim 6 or 7, wherein: The centrifugal clutch unit is arranged on the opposite side of the pressure member with the driving side clutch plate and the driven side clutch plate interposed therebetween. The first pressing contact force and the second pressing contact force are applied in a direction from the centrifugal clutch unit toward the pressure member, The third press-contact force is applied in a direction from the pressure member toward the centrifugal clutch unit.

9. The power transmission device according to claim 1, wherein: The rotation speed of the driving source at which the pressing contact force increasing mechanism starts to operate is different from the rotation speed of the driving source at which the auxiliary cam mechanism starts to operate.

10. The power transmission device according to claim 9, wherein: The rotation speed of the driving source at which the pressing contact force increasing mechanism starts to operate is lower than the rotation speed of the driving source at which the auxiliary cam mechanism starts to operate.

11. The power transmission device according to claim 1, wherein: The range of the rotation speed of the driving source in which the pressing contact force increasing mechanism operates is different from the range of the rotation speed of the driving source in which the auxiliary cam mechanism operates.

12. The power transmission device according to claim 11, wherein: The range of the rotation speed of the driving source in which the auxiliary cam mechanism operates is wider than the range of the rotation speed of the driving source in which the pressing contact force increasing mechanism operates.

13. The power transmission device according to claim 1, wherein: The rotation speed of the driving source at which the auxiliary cam mechanism starts to operate is different from the rotation speed of the driving source at which the pressing contact force increasing mechanism ends to operate.

14. The power transmission device according to claim 13, wherein: The rotation speed of the driving source at which the auxiliary cam mechanism starts to operate is lower than the rotation speed of the driving source at which the pressing contact force increasing mechanism ends to operate.

15. The power transmission device according to claim 13, wherein: The rotation speed of the driving source when the auxiliary cam mechanism starts to operate is lower than the rotation speed of the driving source when the weight member is completed to move to the outer diameter side position.

Images