WO2023166956A1

WO2023166956A1 - Continuously variable transmission

Info

Publication number: WO2023166956A1
Application number: PCT/JP2023/004615
Authority: WO
Inventors: 諭川頭; 克吉本; 友太横道
Original assignee: 株式会社エフ・シー・シー
Priority date: 2022-03-02
Filing date: 2023-02-10
Publication date: 2023-09-07
Also published as: WO2023166955A1; WO2023166872A1; JPWO2023166872A1; JP7348427B1

Abstract

A continuously variable transmission 100 comprises a movable drive pulley 110 between a fixed drive pulley 102 and a ramp plate 130. The movable drive pulley 110 is provided with: an outer circumferential wall 118 positioned outside a center cylinder 111 in a radial direction; a storage 113 which is formed between the center cylinder 111 and the outer circumferential wall 118, which stores a weight 120, and a part of which is partitioned by the outer circumferential wall 118; a first recess 118D which is formed in the outer circumferential wall 118, and which is recessed in a first direction D1, from the end surface 118T in a second direction D2 of a part of the outer circumferential wall 118 partitioning the storage 113; and an internal space 118S connected with the first recess 118D and positioned on the radially inner side of the first recess 118D.

Description

continuously variable transmission

The present invention relates to a continuously variable transmission that continuously transmits rotational driving force of a power source such as an engine to a clutch.

Conventionally, there has been known a continuously variable transmission that continuously transmits the rotational driving force of a power source (for example, an engine) of a straddle-type vehicle such as a motorcycle to a clutch. For example, in Patent Document 1, a ramp plate that rotates by the rotational driving force of an engine, a movable sheave that rotates in synchronization with the ramp plate (hereinafter referred to as a movable drive pulley), and a structure between the ramp plate and the movable drive pulley are disclosed. A continuously variable transmission is disclosed having radially disposed and radially moving centrifugal weights.

JP 2012-47292 A

By the way, in the continuously variable transmission described in Patent Document 1, the V-belt slides on the movable drive pulley, so the movable drive pulley is heated. Here, in the continuously variable transmission described in Patent Literature 1, the accommodating portion that accommodates the centrifugal weight is surrounded by an annular stepped portion (outer peripheral wall). Also, regardless of the position of the centrifugal weight, the ramp plate is arranged to cover the movable drive pulley. That is, the accommodating portion that accommodates the centrifugal weight is covered with the ramp plate. As a result, heat remains between the ramp plate and the movable drive pulley, and heat cannot be dissipated from the movable drive pulley. When the temperature of the movable drive pulley rises, the wear of the V-belt is accelerated, and there is a problem that the life of the V-belt is shortened.

The present invention has been made in view of this point, and its object is to provide a continuously variable transmission excellent in cooling the movable drive pulley.

A continuously variable transmission according to the present invention comprises: a fixed drive pulley that rotates integrally with a crankshaft that is driven to rotate by a power source; a drive pulley having a movable drive pulley approaching or spaced apart from, and a ramp plate disposed on the opposite side of the movable drive pulley from the fixed drive pulley and integrally rotatably driven with the crankshaft; and a weight sandwiched between the movable drive pulley and the ramp plate and movable in the radial direction of the movable drive pulley, wherein the weight moves in the radial direction due to centrifugal force accompanying rotation of the movable drive pulley. configured to move from the inner position to the radially outer position to urge the movable drive pulley to bring the movable drive pulley closer to the fixed drive pulley, the movable drive pulley being adapted to engage the crankshaft; an outer peripheral wall located outside the center tubular portion in the radial direction; and a center tubular portion formed between the center tubular portion and the outer peripheral wall and accommodating the weight. and a direction in which the movable drive pulley separates from the ramp plate is defined as a first direction, and a direction in which the movable drive pulley approaches the ramp plate is defined as a second direction. a recess formed in the outer peripheral wall and recessed in the first direction from an end portion in the second direction of a portion of the outer peripheral wall that defines the housing portion, and the recess and an internal space located inside the recess in the radial direction.

According to the continuously variable transmission according to the present invention, the movable drive pulley is formed on the outer peripheral wall located radially outside the center tubular portion, and is a portion of the outer peripheral wall that defines the accommodation portion that accommodates the weight. and an internal space communicating with the recess and positioned radially inward of the recess. Therefore, air flows into the internal space through the recess formed in the outer peripheral wall, and the air in the internal space is discharged to the outside. That is, the heated air remaining in the internal space is discharged to the outside of the movable drive pulley, and the external air flows into the internal space, thereby cooling the internal space. This cools the movable drive pulley. Here, since the recess is recessed in the first direction from the end in the second direction of the portion of the outer peripheral wall that defines the housing portion, the portion of the movable drive pulley closer to the fixed drive pulley (for example, the V-belt) is recessed in the first direction. can cool the vicinity of the sliding surface where the

Further, another continuously variable transmission according to the present invention includes: a fixed drive pulley that rotates integrally with a crankshaft that is driven to rotate by a power source; a drive pulley having a movable drive pulley that approaches or separates from the fixed drive pulley; and a drive pulley that is disposed on the opposite side of the movable drive pulley from the fixed drive pulley and is rotatably driven integrally with the crankshaft. and a weight sandwiched between the movable drive pulley and the ramp plate and movable in the radial direction of the movable drive pulley, wherein the weight is moved by centrifugal force accompanying rotation of the movable drive pulley. configured to move from the radially inner position to the radially outer position to press the movable drive pulley to bring the movable drive pulley closer to the fixed drive pulley, wherein the movable drive pulley is configured to: a central tubular portion that slides along the crankshaft; an outer peripheral wall that is located radially outside the center tubular portion; an accommodation portion that accommodates a weight and is partly partitioned by the outer peripheral wall; When the direction is the second direction, a recess formed in the outer peripheral wall and recessed in the first direction, and an interior that communicates with the recess and is located inside the recess in the radial direction. and a space, wherein when the weight is positioned inside the radial direction, the ramp plate is positioned on the second direction side of the internal space and is seen from the axial direction of the crankshaft. and overlaps a portion of the interior space.

According to another continuously variable transmission according to the present invention, the movable drive pulley is formed on the outer peripheral wall located radially outside the center cylindrical portion, and defines the accommodating portion for accommodating the weight in the outer peripheral wall. and an internal space that communicates with the recess and is located radially inward of the recess. Therefore, air flows into the internal space through the recess formed in the outer peripheral wall, and the air in the internal space is discharged to the outside. That is, the heated air remaining in the internal space is discharged to the outside of the movable drive pulley, and the external air flows into the internal space, thereby cooling the internal space. This cools the movable drive pulley.

According to the present invention, it is possible to provide a continuously variable transmission excellent in cooling the movable drive pulley.

FIG. 1 is a cross-sectional view schematically showing configurations of a continuously variable transmission and a centrifugal clutch according to one embodiment. FIG. 2 is an enlarged cross-sectional view showing an enlarged part of the continuously variable transmission according to one embodiment. FIG. 3 is an assembly perspective view showing an assembly state of the sleeve bearing, movable drive pulley, weight, and ramp plate of the continuously variable transmission according to one embodiment. FIG. 4 is an exploded perspective view of a fixed drive pulley, a sleeve bearing, a movable drive pulley, a weight, and a ramp plate of a continuously variable transmission according to one embodiment. FIG. 5 is an enlarged cross-sectional view showing a state in which the continuously variable transmission according to one embodiment is rotationally driven at a high rotational speed. FIG. 6 is a perspective view of a movable drive pulley of a continuously variable transmission according to one embodiment; FIG. 7A is a perspective view of a weight according to one embodiment; FIG. 7B is a perspective view of a body cover according to one embodiment; FIG. 7C is a perspective view of a weight body according to one embodiment. 8A is a perspective view of a ramp plate of a continuously variable transmission according to one embodiment; FIG. FIG. 8B is a plan view of a ramp plate of a continuously variable transmission according to one embodiment; FIG. 9 is a plan view showing a state in which the lamp-side protruding piece according to the embodiment abuts on the weight and the weight abuts on the weight receiving portion. FIG. 10 is a plan view showing the relationship between the lamp-side projecting piece, the weight, and the weight receiving portion when the engine is stopped. FIG. 11 is a plan view showing another relationship between the lamp-side protruding piece, the weight, and the weight receiving portion when the engine is stopped. FIG. 12 is a plan view showing a state in which the weight according to one embodiment has moved to a radially outer position. FIG. 13 is a perspective view showing an assembled state of a ramp plate and a movable drive pulley according to one embodiment. FIG. 14 is a plan view showing an assembled state of the ramp plate and the movable drive pulley according to one embodiment. FIG. 15 is a side view showing the positional relationship between the ramp plate and the movable drive pulley when the weight according to one embodiment is positioned radially outward. FIG. 16 is a side view showing the positional relationship between the ramp plate and the movable drive pulley when the weight according to one embodiment is positioned radially inward. FIG. 17 is a plan view showing part of a modification of the movable drive pulley.

An embodiment of a continuously variable transmission according to the present invention will be described below with reference to the drawings. It should be noted that the embodiments described herein are, of course, not intended to limit the invention in particular. Further, members and portions having the same function are denoted by the same reference numerals, and overlapping descriptions are appropriately omitted or simplified. In this specification, the radial direction means the radial direction of the movable drive pulley 110 and the ramp plate 130 unless otherwise specified.

The continuously variable transmission 100 is a device that is mainly used for straddle-type vehicles (for example, motorcycles such as scooters). As shown in FIG. 1, a continuously variable transmission 100 is provided between a power source (for example, an engine) and a centrifugal clutch 200 on the rear wheel side, which is a driving wheel. Continuously variable transmission 100 transmits rotational driving force to centrifugal clutch 200 while steplessly changing a reduction ratio with respect to engine speed.

(Configuration of continuously variable transmission 100)
As shown in FIG. 1 , continuously variable transmission 100 includes drive pulley 101 , weight 120 , ramp plate 130 , V-belt 140 and driven pulley 150 . The drive pulley 101 is provided on a crankshaft 90 that is rotationally driven by the engine. The drive pulley 101 is a component that is directly rotationally driven by the rotational driving force of the engine. The drive pulley 101 has a fixed drive pulley 102 and a movable drive pulley 110 arranged opposite the fixed drive pulley 102 . In the following description, the direction in which the fixed drive pulley 102, the movable drive pulley 110, and the ramp plate 130 rotate is referred to as the rotation direction L (see FIG. 6, etc.).

As shown in FIG. 1, the fixed drive pulley 102 is a component that sandwiches the V-belt 140 together with the movable drive pulley 110 and drives it to rotate. The fixed drive pulley 102 is configured by forming a metal material (for example, an aluminum material) into a conical cylindrical shape. Fixed drive pulley 102 comprises a disc portion 103 , a conical portion 106 and fins 107 .

As shown in FIG. 2 , the disc portion 103 is a portion that connects the fixed drive pulley 102 to the crankshaft 90 and supports the conical portion 106 . The disc portion 103 is a flat plate formed in a ring shape. A fitting hole 103a having an internal spline is formed in the center of the disk portion 103 . The outer peripheral portion of the crankshaft 90 is spline-fitted into the fitting hole 103a. The disk portion 103 is fixed on the crankshaft 90 while being abutted against a sleeve bearing 104 fixedly fitted to the outer peripheral portion of the crankshaft 90 . More specifically, the disk portion 103 is fixed on the crankshaft 90 by a nut 105 that is screwed onto one end (the left side in the drawing) of the crankshaft 90 . As a result, the fixed drive pulley 102 is always rotated integrally with the crankshaft 90 .

As shown in FIG. 2, the conical portion 106 is a portion that sandwiches the V-belt 140 together with the conical portion 112 of the movable drive pulley 110 . The conical portion 106 is formed in a tapered surface that slopes outward in the radial direction of the disc portion 103 . Conical portion 106 is slanted away from movable drive pulley 110 as it moves away from disk portion 103 . Conical portion 106 has a plurality of fins 107 formed on the surface opposite to the surface facing movable drive pulley 110 . The fins 107 are members for releasing the heat of the fixed drive pulley 102 to the outside. The fins 107 are radially provided around the axis of the crankshaft 90 on the outer side of the disc portion 103 . The disc portion 103, the conical portion 106 and the fins 107 are integrally molded.

As shown in FIG. 2, the movable drive pulley 110 is a component that sandwiches the V-belt 140 together with the fixed drive pulley 102 and drives it to rotate. The movable drive pulley 110 is configured by forming a metal material into a conical cylinder. The movable drive pulley 110 has a center tubular portion 111, a conical portion 112, a housing portion 113, an outer peripheral wall 118 (see FIG. 6), and side walls 119 (see FIG. 6).

As shown in FIG. 2 , the center tubular portion 111 is a portion where the movable drive pulley 110 is supported on the crankshaft 90 . As shown in FIG. 6 , the center tubular portion 111 is a substantially tubular wall projecting from the conical portion 112 . Center tube portion 111 extends from conical portion 112 toward lamp plate 130 . The center tubular portion 111 is formed in the center of the conical portion 112 . The center tubular portion 111 partitions the accommodating portion 113 . A through hole 111W into which the sleeve bearing 104 is inserted is formed in the center tubular portion 111 . The center cylindrical portion 111 is mounted on the sleeve bearing 104 via an impregnated bush. The center tubular portion 111 is attached to the sleeve bearing 104 so as to be slidable in the axial direction and the rotational direction L, respectively. The center tubular portion 111 slides along the crankshaft 90 . Thereby, the movable drive pulley 110 is slidably supported along the axial direction and the rotational direction L of the crankshaft 90, as shown in FIG. Movable drive pulley 110 is configured to move toward or away from fixed drive pulley 102 on crankshaft 90 . Movable drive pulley 110 is configured to move toward or away from ramp plate 130 on crankshaft 90 . Here, the direction in which the movable drive pulley 110 moves away from the ramp plate 130 (that is, the direction in which the movable drive pulley 110 approaches the fixed drive pulley 102) is defined as a first direction D1, and the direction in which the movable drive pulley 110 approaches the ramp plate 130. (ie, the direction in which the movable drive pulley 110 moves away from the fixed drive pulley 102) is defined as a second direction D2.

As shown in FIG. 2 , the conical portion 112 is a portion that sandwiches the V-belt 140 together with the conical portion 106 of the fixed drive pulley 102 . The conical portion 112 is formed in a tapered surface that slopes outward in the radial direction of the center cylindrical portion 111 . The cone 112 slopes away from the fixed drive pulley 102 as it moves away from the crankshaft 90 . The conical portion 112 has a receiving portion 113 formed on the surface opposite to the surface facing the fixed drive pulley 102 .

As shown in FIG. 6, the outer peripheral wall 118 is a wall protruding from the conical portion 112 . A peripheral wall 118 extends from the conical portion 112 toward the lamp plate 130 . The outer peripheral wall 118 is located radially outside the center tubular portion 111 . The outer peripheral wall 118 is formed in an annular shape. Note that the shape of the outer peripheral wall 118 is not limited to an annular shape. As will be described later, the outer peripheral wall 118 partitions the housing portion 113 .

As shown in FIG. 6, the movable drive pulley 110 has a plurality of first recesses 118D and a plurality of second recesses 118H. The first recess 118D is an example of a recess. The second recess 118H is an example of another recess.

As shown in FIG. 6, the first recess 118D is formed in the outer peripheral wall 118. As shown in FIG. The first recessed portion 118D is recessed in the first direction D1 from the end surface 118T of the portion of the outer peripheral wall 118 that defines the housing portion 113 in the second direction D2. Here, the end face 118T in the second direction D2 is also the end in the second direction D2. The first concave portion 118D is located between adjacent accommodating portions 113 with respect to the rotational direction L of the movable drive pulley 110 (conical portion 112). Three first recesses 118D are formed along the rotation direction L at equal intervals. The three first recesses 118D are formed in the same shape.

As shown in FIG. 6, the second recess 118H is formed in the outer peripheral wall 118. As shown in FIG. The second recessed portion 118H is located radially outside the accommodating portion 113 . The second recess 118H is recessed radially inward. The second recessed portion 118H extends from the end surface 118T of the outer peripheral wall 118 in the second direction D2 to the conical portion 112 . The second recess 118H is positioned radially outside the movable drive pulley-side weight sliding surface 114 . The second recessed portion 118H is positioned radially inward of an outer side surface 116b of the projecting piece accommodating portion 116, which will be described later.

As shown in FIG. 6, the movable drive pulley 110 has a plurality of internal spaces 118S. The internal space 118S communicates with the first recess 118D. The internal space 118S is positioned radially inward of the first recess 118D. The internal space 118</b>S is located between the side wall 119 that defines one of the housing portions 113 adjacent in the rotation direction L and the side wall 119 that defines the other housing portion 113 . The internal space 118S is defined by the side wall 119 and the conical portion 112. As shown in FIG. Three internal spaces 118S are formed along the rotation direction L at equal intervals. The three internal spaces 118S are formed in the same shape. As shown in FIG. 12, the length L1 of the internal space 118S in the rotation direction L is longer than the length L2 of the housing portion 113 in the rotation direction L. As shown in FIG.

As shown in FIG. 6, the sidewall 119 is a wall protruding from the conical portion 112 . Sidewall 119 extends from cone 112 toward lamp plate 130 . Side wall 119 connects center cylindrical portion 111 and outer peripheral wall 118 . Side wall 119 extends in a direction intersecting with rotation direction L. As shown in FIG. Here, the conical portion 112 is provided with three pairs of sidewalls 119 (ie, six sidewalls 119). As will be described later, the pair of side walls 119 partition the housing portion 113 . The end surface 111T of the center tubular portion 111 in the second direction D2, the end surface 119T of the side wall 119 in the second direction D2, and the end surface 118T of the outer peripheral wall 118 in the second direction D2 are formed flush with each other.

As shown in FIG. 2, the accommodation portion 113 is a portion that movably accommodates the weight 120 and a lamp-side protruding piece 133 of the lamp plate 130, which will be described later. The accommodating portion 113 is formed to be recessed in a state of protruding from the board surface of the conical portion 112 . The accommodating portion 113 is formed between the center tubular portion 111 and the outer peripheral wall 118 . The accommodating portion 113 is formed by being partitioned into a center tubular portion 111 , a pair of side walls 119 and an outer peripheral wall 118 . As shown in FIG. 6 , three accommodating portions 113 are formed at equal intervals along the rotation direction L of the conical portion 112 . The three housing portions 113 are formed in the same shape. Specifically, the accommodating portion 113 includes a movable drive pulley side weight sliding surface 114 , a weight receiving portion 115 , a projecting piece accommodating portion 116 and a projecting piece receiving portion 117 .

As shown in FIG. 2, the movable drive pulley-side weight sliding surface 114 is a surface that sandwiches the weight 120 in a radially movable state together with a later-described ramp-side weight sliding surface 132 of the ramp plate 130 . A weight 120 slides on the movable drive pulley-side weight sliding surface 114 . The movable drive pulley-side weight sliding surface 114 extends radially. The movable drive pulley-side weight sliding surface 114 is a smooth surface extending in the radial direction. The movable drive pulley-side weight sliding surface 114 is inclined such that the radially outer portion is positioned closer to the ramp plate 130 than the radially inner portion. The movable drive pulley-side weight sliding surface 114 includes a planar portion 114a positioned radially inward and formed in a planar shape, and a curved surface portion 114b positioned radially outward and formed in a curved shape. . The flat portion 114a and the curved portion 114b are continuous in the radial direction.

As shown in FIG. 6, the weight receiving portion 115 receives the first end portion 122c (see FIG. 4) of the weight 120 arranged on the movable drive pulley side weight sliding surface 114, and applies the rotational driving force of the ramp plate 130. As shown in FIG. This is the part that receives The weight receiving portion 115 is formed on the side wall 119 . The weight receiving portion 115 is formed at a position adjacent to the movable drive pulley side weight sliding surface 114 with respect to the rotation direction L. As shown in FIG. The weight receiving portion 115 is positioned downstream in the rotational direction L from the movable drive pulley side weight sliding surface 114 . The weight receiving portion 115 is a surface extending in a direction intersecting the rotational direction L of the movable drive pulley 110 .

As shown in FIG. 6, the projecting piece accommodating portion 116 is a portion that accommodates a lamp-side projecting piece 133 (see FIG. 8A) of the lamp plate 130, which will be described later. The protruding piece accommodating portion 116 is a recessed bottomed hole. The protruding piece accommodating portion 116 is positioned adjacent to the movable drive pulley side weight sliding surface 114 on the side opposite to the weight receiving portion 115 with respect to the rotational direction L so that the movable drive pulley 110 is positioned closer to the movable drive pulley side weight sliding surface 114 than the movable drive pulley side weight sliding surface 114 . and extending in a direction crossing the rotational direction L of the movable drive pulley 110 . The radial length of the protruding piece accommodating portion 116 is longer than the radial length of the movable drive pulley-side weight sliding surface 114 .

As shown in FIG. 6, the projecting piece accommodating portion 116 includes a weight-side end face 116a, a projecting piece receiving portion 117, an outer side surface 116b, and an inner side surface 116c. The projecting piece accommodating portion 116 is formed in a concave shape that opens toward the lamp plate 130 . Here, the weight-side end surface 116 a is formed by cutting the protruding piece accommodating portion 116 into a concave shape at a position adjacent to the movable drive pulley-side weight sliding surface 114 , thereby forming the weight-side end surface 116 a. is a portion exposed in the protruding piece accommodating portion 116 .

Further, as shown in FIG. 6, the outer surface 116b is a surface that connects the movable drive pulley-side weight sliding surface 114 and the protruding piece receiving portion 117 at a radially outer portion of the movable drive pulley 110. As shown in FIG. The outer surface 116 b is formed on the outer peripheral wall 118 . The inner side surface 116c is a surface that connects the movable drive pulley side weight sliding surface 114 and the projecting piece receiving portion 117 at a radially inner portion of the movable drive pulley 110 . The inner side surface 116c is formed on the center tubular portion 111 . Further, the groove width S of the projecting piece accommodating portion 116 is formed to be slightly larger than the plate thickness T of the lamp-side projecting piece 133 (see FIG. 8A).

As shown in FIG. 6, when the engine is decelerated, the projecting piece receiving portion 117 receives the lamp-side projecting piece 133 (see FIG. 8A) positioned in the projecting piece accommodating portion 116 and applies the rotational driving force (see FIG. 8A) of the movable drive pulley 110. It is the part that receives the back torque). The projecting piece receiving portion 117 is formed on the side wall 119 . The protruding piece receiving portion 117 is provided at a position facing the weight receiving portion 115 . The projecting piece receiving portion 117 is formed substantially parallel to the weight receiving portion 115 . The protruding piece receiving portion 117 is formed parallel to the axial direction of the movable drive pulley 110 at a position adjacent to the movable drive pulley side weight sliding surface 114 on the side opposite to the weight receiving portion 115 in the rotation direction L. The protruding piece receiving portion 117 is positioned upstream in the rotational direction L from the movable drive pulley side weight sliding surface 114 . The projecting piece receiving portion 117 is a surface extending in a direction intersecting the rotational direction L of the movable drive pulley 110 .

As shown in FIG. 6, the weight sliding surface 114 on the movable drive pulley side, the weight receiving portion 115, the projecting piece receiving portion 116, and the projecting piece receiving portion 117 are integrally connected to form a recessed receiving portion 113. is formed. In this embodiment, the three accommodating portions 113 are formed integrally with the center tubular portion 111 and the conical portion 112 when the movable drive pulley 110 is processed by aluminum die casting.

As shown in FIG. 9 , the weight 120 is housed in the housing portion 113 of the movable drive pulley 110 . The weight 120 is housed in the housing portion 113 so that the center line C3 of the weight 120 is perpendicular to the radial direction when the lamp-side protruding piece 133 is in contact with the weight 120 and the weight 120 is in contact with the weight receiving portion 115. ing. The weight 120 is provided so as to be freely movable (displaceable) in the radial direction of the movable drive pulley 110 . In the process from the state where the engine is stopped (that is, the state where the crankshaft 90 is not rotating) until the ramp plate 130 rotates and the weight 120 comes into contact with the ramp-side protruding piece 133 and the weight receiving portion 115, the weight 120 is It is configured to be radially movable. As the ramp plate 130 rotates while the engine speed reaches from the cranking speed (for example, 50 rpm to 60 rpm) to the idling speed (for example, 600 rpm to 800 rpm), the weight 120 is moved to the lamp side protruding piece 133 and the weight. It is configured to come into contact with the receiving portion 115 . It should be noted that the number of revolutions of the engine when the ramp-side protruding piece 133 abuts on the weight 120 and the weight 120 abuts on the weight receiving portion 115 is the engine speed when the movable drive pulley 110 starts approaching the fixed drive pulley 102. lower than the rpm of the The weight 120 moves from the radially inner position (see FIG. 2) to the radially outer position (see FIG. 2) as the rotational speed of the movable drive pulley 110 increases (that is, due to the centrifugal force accompanying the rotation of the movable drive pulley 110). 5). When the weight 120 is in contact with the ramp-side projecting piece 133 and the weight receiving portion 115, the weight 120 moves along the movable drive pulley-side weight sliding surface 114 and the ramp-side weight sliding surface 132 from a radially inner position. It is configured to be movable to a radially outer position. Weight 120 is sandwiched between movable drive pulley 110 and ramp plate 130 . Weights 120 are configured to push movable drive pulley 110 to bring movable drive pulley 110 closer to fixed drive pulley 102 . The weight 120 is a component that cooperates with the ramp plate 130 to press the movable drive pulley 110 toward the fixed drive pulley 102 side. The weight 120 includes a weight body 121 and a body cover 122, as shown in FIGS. 7A to 7C. The weight body 121 is a component that functions as a weight in the weight 120 . The weight main body 121 is configured by forming a metal material into a cylindrical shape. The weight body 121 is fitted into and integrated with the body cover 122 .

The body cover 122 is made of a resin material (for example, polyamide resin). By forming body cover 122 from a resin material, slidability and wear resistance between body cover 122 and movable drive pulley 110 and ramp plate 130 can be improved. The body cover 122 contacts the movable drive pulley side weight sliding surface 114 and the ramp side weight sliding surface 132 . The body cover 122 slides on the movable drive pulley side weight sliding surface 114 and the ramp side weight sliding surface 132 . Body cover 122 is an example of a contact portion. As shown in FIG. 4, the body cover 122 has a first sliding surface 122a (see FIG. 7A), a second sliding surface 122b, a first end 122c and a second end 122d.

As shown in FIG. 2, the first sliding surface 122a is a surface that slides on the movable drive pulley-side weight sliding surface 114. As shown in FIG. The first sliding surface 122a is a curved surface with an arc-shaped cross section. As a result, the first sliding surface 122 a and the movable drive pulley side weight sliding surface 114 are in line contact, so that the weight 120 can move smoothly on the movable drive pulley side weight sliding surface 114 . The second sliding surface 122b is a surface that slides on a ramp-side weight sliding surface 132, which will be described later. The second sliding surface 122b is a plane having a linear cross section. As a result, it is possible to prevent the weight 120 from rotating and moving on the movable drive pulley-side weight sliding surface 114 . The second sliding surface 122b is an example of a weight-side flat portion. A notch 122e (see FIG. 7B) is formed in a portion of the body cover 122 adjacent to the first sliding surface 122a and the second sliding surface 122b. The weight body 121 is inserted into the body cover 122 through the notch 122e. The weight body 121 is exposed to the outside through the notch 122e.

The weight 120 is configured to be able to contact the lamp-side projecting piece 133 . The weight 120 is configured to contact the weight receiving portion 115 . As shown in FIG. 9, the first end portion 122c is configured to be able to contact the weight receiving portion 115. As shown in FIG. The first end portion 122 c is a portion that presses the weight receiving portion 115 . The first end 122c is a flat surface that covers one axial end of the weight body 121 (the downstream end in the rotational direction L). The first end 122c is an example of a first surface. The second end portion 122d is configured to be able to come into contact with the lamp-side protruding piece 133. As shown in FIG. The second end portion 122 d is a portion that receives pressure from the lamp-side projecting piece 133 . The second end 122d is a flat surface that covers the other axial end of the weight body 121 (the upstream end in the rotational direction L). The main body cover 122 is formed to have a length such that a part of the second end 122d is located in the protruding piece accommodating portion 116 while the first end 122c is in contact with the weight receiving portion 115 .

As shown in FIG. 9, when the weight 120 is housed in the housing portion 113 (more specifically, the lamp-side protruding piece 133 is in contact with the weight 120 and the weight 120 is in contact with the weight receiving portion 115), A length P1 of the weight 120 in a direction perpendicular to the radial direction and the axial direction of the crankshaft 90 is longer than a radial length P2 of the weight 120 . Here, length P1 is the length of weight 120 in the longitudinal direction. Also, when viewed from the axial direction of the crankshaft 90, the normal line C2 of the circle C1 centered on the rotation center 110C of the movable drive pulley 110 passes through the first end 122c and the second end 122d of the weight 120. . Here, the case where the weight 120 is tilted and stored in the storage portion 113 is also included. Further, when the lamp-side protruding piece 133 is in contact with the weight 120 and the weight 120 is in contact with the weight receiving portion 115, the center line C3 of the weight 120 perpendicular to the radial direction and the axial direction of the crankshaft 90 is , overlaps the normal C2 when viewed from the axial direction of the crankshaft 90 .

As shown in FIG. 2, the ramp plate 130 is a component that presses the weight 120 toward the movable drive pulley 110 side. The ramp plate 130 is located on the opposite side of the movable drive pulley 110 from the fixed drive pulley 102 . The ramp plate 130 is rotationally driven integrally with the crankshaft 90 . The lamp plate 130 is made of a metal material (eg, aluminum material). The lamp plate 130 is a disc-shaped flat plate. More specifically, as shown in FIG. 8A, the lamp plate 130 includes a disk portion 131, a projecting member 132R having a lamp-side weight sliding surface 132, a lamp-side projecting piece 133, and a fin 134 (see FIG. 4). ).

As shown in FIG. 8A, the disc portion 131 is a flat plate formed in a disc shape. A projecting member 132</b>R having a ramp-side weight sliding surface 132 and a ramp-side projecting piece 133 are formed on the surface of the disk portion 131 facing the movable drive pulley 110 . 131 C of through-holes are formed in the center part in the disk part 131. As shown in FIG. The outer peripheral portion of the crankshaft 90 is integrally attached to the through hole 131C. Therefore, the ramp plate 130 is always rotated integrally with the crankshaft 90 .

As shown in FIG. 2, the projecting member 132R is a wall that rises from the surface of the disc portion 131 toward the movable drive pulley 110. As shown in FIG. The protruding member 132R is positioned on the side of the lamp-side protruding piece 133 (downstream side in the rotation direction L). The protruding member 132R can be accommodated in the accommodating portion 113. As shown in FIG. The ramp-side weight sliding surface 132 of the protruding member 132R is a surface that sandwiches the weight 120 together with the movable drive pulley-side weight sliding surface 114 of the movable drive pulley 110 in a radially movable state. The weight 120 slides on the ramp-side weight sliding surface 132 . The ramp-side weight sliding surface 132 extends radially. The ramp-side weight sliding surface 132 is a smooth surface extending in the radial direction. The ramp-side weight sliding surface 132 is inclined such that the radially outer portion is positioned closer to the movable drive pulley 110 than the radially inner portion. As shown in FIG. 8A, three ramp-side weight sliding surfaces 132 are formed at equal intervals along the rotation direction L of the disc portion 131 . The ramp-side weight sliding surface 132 has a ramp-side planar portion 132a formed in a planar shape. The second sliding surface 122b of the weight 120 contacts the ramp-side flat portion 132a. The second sliding surface 122b slides on the lamp-side flat portion 132a.

As shown in FIG. 9, the lamp-side protruding piece 133 is accommodated in the protruding piece accommodating portion 116 . The ramp-side projecting piece 133 is positioned upstream in the rotational direction L with respect to the weight 120 . The lamp-side protruding piece 133 extends in a direction intersecting with the rotation direction L when viewed from the axial direction of the crankshaft 90 . The lamp-side projecting piece 133 is provided so as to contact the weight 120 . The lamp-side protruding piece 133 is provided so as to be able to contact the protruding piece receiving portion 117 . The lamp-side protruding piece 133 is configured to be movable in the rotational direction L relative to the housing portion 113 in a state of being housed in the housing portion 113 . The lamp-side protruding piece 133 presses the second end 122d of the weight 120 by the rotational driving force of the engine. The ramp-side projecting piece 133 indirectly presses the movable drive pulley 110 via the weight 120 by the rotational driving force of the engine. When back torque acts on the continuously variable transmission 100 from the driving wheels, the second pressing surface 133b (see FIG. 10) of the ramp-side projecting piece 133 receives the pressing force from the projecting piece receiving portion 117 of the movable drive pulley 110. receive. Then, the rotational driving force (back torque) transmitted to the lamp-side projecting piece 133 is transmitted to the crankshaft 90 . The ramp-side projecting piece 133 receives a pressing force from the second end portion 122 d due to the rotational driving force (back torque) from the movable drive pulley 110 . The lamp-side protruding piece 133 is a wall that rises from the surface of the disk portion 131 toward the movable drive pulley 110 . More specifically, as shown in FIG. 10, the lamp-side protruding piece 133 is arranged to face the second end 122d of the weight 120, and is in planar contact with the second end 122d. It has a first pressing surface 133 a (see also FIG. 3 ) and a planar second pressing surface 133 b that is arranged to face the projecting piece receiving portion 117 and is in surface contact with the projecting piece receiving portion 117 . The first pressing surface 133a is sized to contact a portion of the second end 122d of the weight 120, but may be sized to contact the entire surface of the second end 122d.

As shown in FIG. 8A, three lamp-side protruding pieces 133 are formed at equal intervals along the rotation direction L of the disc portion 131 . The lamp-side protruding piece 133 is formed integrally with the side surface of the lamp-side weight sliding surface 132 formed on the disk portion 131 . That is, the lamp plate 130 is formed by integrally molding a disk portion 131, three lamp-side weight sliding surfaces 132, and three lamp-side protruding pieces 133 by aluminum die-cast molding. 1, 2 and 5, although the lamp-side projecting piece 133 is not originally shown, it is intentionally shown by a two-dot chain line in order to clarify the positional relationship of the lamp-side projecting piece 133. As shown in FIG.

As shown in FIG. 4 , a plurality of fins 134 are formed on the surface of the ramp plate 130 (more specifically, the disk portion 131 ) opposite to the surface facing the movable drive pulley 110 . Fins 134 extend radially. The fins 134 are radially formed. By providing the fins 134 on the lamp plate 130, the lamp plate 130 can be cooled more effectively and the rigidity of the lamp plate 130 is increased.

As shown in FIG. 13, when the weight 120 is positioned radially inward (see FIG. 2), the ramp plate 130 is positioned on the second direction D2 side of the internal space 118S. As shown in FIG. 14 , when the weight 120 is positioned radially inward, the ramp plate 130 partially overlaps the internal space 118S when viewed from the axial direction of the crankshaft 90 . The ramp plate 130 does not overlap the first recessed portion 118D when viewed from the axial direction of the crankshaft 90 . The ramp plate 130 overlaps the second recessed portion 118H when viewed from the axial direction of the crankshaft 90 .

As shown in FIG. 15 , when the weight 120 is positioned radially outward (see FIG. 5 ), when viewed from the radial direction of the crankshaft 90 A through-hole 160 is formed. An air flow path is formed by the through hole 160 . Air outside ramp plate 130 and movable drive pulley 110 flows through through hole 160 into the space surrounded by ramp plate 130 and movable drive pulley 110 , and then flows outside ramp plate 130 and movable drive pulley 110 . flow to A portion of the through-hole 160 is defined by the lamp-side projecting piece 133 and the projecting member 132R. Through hole 160 includes lamp-side protruding piece 133, protruding member 132R, weight 120, movable drive pulley 110 (more specifically, outer peripheral wall 118), and ramp plate 130 (more specifically, disk portion 131). are separated by Further, the end portion 120T of the weight 120 in the second direction D2 when the weight 120 is positioned radially outward is the end portion of the movable drive pulley 110 in the second direction D2 (here, for example, the end portion of the outer peripheral wall 118). 2 end surface 118T) in the second direction D2).

As shown in FIG. 16, even when the weight 120 is positioned radially inward (see FIG. 2) (for example, when the engine is stopped or idling), when viewed from the radial direction of the crankshaft 90, the ramp plate A through hole 160 is formed between 130 and movable drive pulley 110 . In this way, when the weight 120 is positioned radially inwardly and positioned radially outwardly, there is a gap between the ramp plate 130 and the movable drive pulley 110 when viewed from the radial direction of the crankshaft 90 . is formed with a through hole 160 .

As shown in FIG. 1, the V-belt 140 is a component for transmitting the rotational driving force of the drive pulley 101 to the driven pulley 150. As shown in FIG. The V-belt 140 is formed in an endless ring shape with a core wire covered with a resin material. V-belt 140 is disposed between fixed drive pulley 102 and movable drive pulley 110 of drive pulley 101 and between fixed driven pulley 151 and movable driven pulley 154 of driven pulley 150 to connect drive pulley 101 and driven pulley 150 . is erected between

As shown in FIG. 1 , the driven pulley 150 is a component that transmits the rotational power of the engine transmitted from the drive pulley 101 via the V-belt 140 to the centrifugal clutch 200 . The driven pulley 150 includes a fixed driven pulley 151 , a driven sleeve 152 and a movable driven pulley 154 .

As shown in FIG. 1, the fixed driven pulley 151 and the movable driven pulley 154 are components that rotate while holding the V-belt 140 therebetween. The fixed driven pulley 151 is configured by forming a metal material (for example, an aluminum material) into a conical cylinder. The fixed driven pulley 151 is fixed on the driven sleeve 152 with the convex surface facing the movable driven pulley 154 side.

The driven sleeve 152 is a metallic cylindrical part that rotates integrally with the fixed driven pulley 151 . The driven sleeve 152 is rotatably attached to the drive shaft 153 via a bearing. The drive shaft 153 is a metal rotating shaft for driving the rear wheels of the motorcycle on which the continuously variable transmission 100 is mounted via a transmission (not shown). A rear wheel of the motorcycle is attached to one end (right side in the figure) of the drive shaft 153 .

As shown in FIG. 1, the movable driven pulley 154 is a component that rotates while holding the V-belt 140 with the fixed driven pulley 151. The movable driven pulley 154 is made of a metal material (eg, aluminum material). It is formed in a conical cylindrical shape. The movable driven pulley 154 is axially slidably fitted to the driven sleeve 152 with its convex surface facing the fixed driven pulley 151 .

On the other hand, a torque spring 155 is provided between the concave side surface of the movable driven pulley 154 and the drive plate 201 of the centrifugal clutch 200 . The torque spring 155 is a coil spring that elastically presses the movable driven pulley 154 toward the fixed driven pulley 151 side. That is, the continuously variable transmission 100 has a diameter across the V-belt 140 defined by the distance between the fixed drive pulley 102 and the movable drive pulley 110, and a V diameter defined by the distance between the fixed driven pulley 151 and the movable driven pulley 154. The rotational speed of the drive shaft 153 is changed steplessly according to the size relationship with the diameter of the belt 140 . A centrifugal clutch 200 is provided on the tip side of each of the driven sleeve 152 and the drive shaft 153 .

The centrifugal clutch 200 will be briefly explained. Centrifugal clutch 200 is a device that transmits or blocks the rotational driving force of the engine transmitted through continuously variable transmission 100 to drive shaft 153 . Centrifugal clutch 200 includes drive plate 201 , three clutch weights 203 and clutch outer 206 .

The drive plate 201 is a part that rotates integrally with the driven sleeve 152 . The drive plate 201 is configured by forming a metal material into a stepped disc shape. At the outer edge of the board surface of the drive plate 201, three rocking support pins 202 are provided in a state of standing upright in the rotation direction L. As shown in FIG. Clutch weights 203 are respectively supported by the swing support pins 202 .

The three clutch weights 203 are parts for transmitting or blocking the rotational driving force from the engine to the drive shaft 153 according to the number of revolutions of the drive plate 201 respectively. The clutch weight 203 is formed by forming a curved shape extending along the rotation direction L of the drive plate 201 from a metal material (for example, zinc material). The three clutch weights 203 are mutually pulled radially inward by a connecting spring 204 . Clutch shoe 205 is a component for increasing the frictional force against the inner peripheral surface of clutch outer 206 . Clutch shoe 205 is configured by forming a friction material into a plate shape extending in an arc shape.

One end of the clutch weight 203 is supported by the swing support pin 202 in a swingable state with the clutch shoe 205 facing the inner peripheral surface of the clutch outer 206 . As a result, in the three clutch weights 203 , the clutch shoes 205 come into contact with or separate from the inner peripheral surface of the clutch outer 206 according to the rotational speed of the drive plate 201 .

The clutch outer 206 is a part that rotates integrally with the drive shaft 153 . Clutch outer 206 is formed by forming a metal material into a cup shape that covers the outer peripheral surface of clutch weight 203 from drive plate 201 . Clutch outer 206 transmits or blocks rotational driving force from the engine to drive shaft 153 by contact of clutch weight 203 via clutch shoe 205 .

(Operation of continuously variable transmission 100)
Next, the operation of the continuously variable transmission 100 of this embodiment will be described. The continuously variable transmission 100 functions as a part of a power transmission mechanism arranged between an engine of a motorcycle such as a scooter and rear wheels, which are driving wheels. Before the continuously variable transmission 100 operates (for example, when the engine is stopped), the elastic force of the torque spring 155 causes the movable driven pulley 154 to be closest to the fixed driven pulley 151 . Therefore, the movable drive pulley 110 is located at the farthest position from the fixed drive pulley 102 (see FIGS. 1 and 2). When the engine is stopped, the weight 120 is sandwiched between the movable drive pulley-side weight sliding surface 114 and the ramp-side weight sliding surface 132, as shown in FIG. When the engine is stopped, for example, as shown in FIG. 10, a gap is formed between the lamp-side projecting piece 133 and the weight 120, and a gap is formed between the weight 120 and the weight receiving portion 115. There is something. Further, as shown in FIG. 11, a gap may be formed between the lamp-side projecting piece 133 and the weight 120, and the weight 120 and the weight receiving portion 115 may be in contact with each other. Although illustration is omitted, the lamp-side protruding piece 133 and the weight 120 may be in contact with each other, and a gap may be formed between the weight 120 and the weight receiving portion 115 . Further, in the example shown in FIGS. 10 and 11, the weight 120 is arranged so that the center line C3 of the weight 120 is orthogonal to the lamp-side projecting piece 133, but is arranged so that the center line C3 is inclined. (That is, the weight 120 may be inclined with respect to the lamp-side projecting piece 133). In this case, the above-mentioned gap becomes non-uniform with respect to the radial direction.

Next, in the continuously variable transmission 100, when the engine is idling, the fixed drive pulley 102 and the ramp plate 130 are driven to rotate together with the crankshaft 90 by the rotation of the crankshaft 90. At this time, the first pressing surface 133 a of the lamp-side projecting piece 133 of the ramp plate 130 presses the second end 122 d of the weight 120 . As a result, the first end portion 122 c of the weight 120 presses the weight receiving portion 115 . Thus, when the lamp plate 130 rotates, the lamp-side protruding piece 133 abuts the weight 120 and the weight 120 abuts the weight receiving portion 115 . As a result, the movable drive pulley 110 rotates at the same number of rotations as the ramp plate 130 . That is, the movable drive pulley 110 rotates at the same number of revolutions as the crankshaft 90 and the fixed drive pulley 102 .

In this case, since the centrifugal force acting on the weight 120 is smaller than the elastic force of the torque spring 155, the weight 120 is positioned radially inward and does not move radially outward. During idling, the continuously variable transmission 100 keeps the movable drive pulley 110 separated from the fixed drive pulley 102, so that the V-belt 140 moves outward from the innermost circumference of the drive pulley 101. no. Therefore, since the centrifugal force acting on the clutch weight 203 of the centrifugal clutch 200 is smaller than the elastic force (tensile force) of the connecting spring 204, the clutch shoe 205 does not come into contact with the inner peripheral surface of the clutch outer 206, and the engine rotation is reduced. No driving force is transmitted to the drive shaft 153 .

Next, in the continuously variable transmission 100 , when the engine speed increases due to the accelerator operation of the driver on the motorcycle, the centrifugal force acting on the clutch weight 203 of the centrifugal clutch 200 causes the elasticity of the connecting spring 204 to increase. greater than the force (tensile force). As a result, the clutch shoes 205 come into contact with the inner peripheral surface of the clutch outer 206 , so that the rotational driving force of the engine is transmitted to the drive shaft 153 .

As the engine speed further increases, the centrifugal force acting on the weight 120 is determined by the sum of the cam thrust generated by the torque cam groove (not shown) provided in the movable driven pulley 154 and the thrust of the torque spring 155. will also grow. This causes the weight 120 to start moving to the radially outer position. That is, in a state in which the weight 120 is in contact with the ramp-side projecting piece 133 and the weight receiving portion 115, the weight 120 moves along the movable drive pulley-side weight sliding surface 114 from the radially inner position to the radially outer position. start moving to Then, as shown in FIGS. 5 and 12, the weight 120 moves to a radially outer position. Here, the movable drive pulley-side weight sliding surface 114 and the ramp-side weight sliding surface 132 sandwiching the weight 120 are formed so that the distance between them narrows from the inner side to the outer side in the radial direction. Therefore, the movable drive pulley 110 moves toward the fixed drive pulley 102 as the weight 120 moves radially outward. That is, when the movable drive pulley 110 approaches the fixed drive pulley 102, the V-belt 140 moves from the innermost peripheral portion of the drive pulley 101 to the outer peripheral side and moves from the outermost peripheral portion of the driven pulley 150 to the inner peripheral side. Moving.

Next, when the engine speed decreases due to the driver's accelerator operation, the weight 120 moves from the radially outer position toward the radially inner position as the centrifugal force acting on the weight 120 decreases. At this time, the movable drive pulley 110 is separated from the fixed drive pulley 102 by the elastic force of the torque spring 155 . That is, continuously variable transmission 100 returns to the above-described idling state as the engine speed decreases (see FIG. 1 or FIG. 2).

In addition, back torque may act on the continuously variable transmission 100 from the driving wheels. In this case, the second pressing surface 133 b of the lamp-side projecting piece 133 receives the pressing force from the projecting piece receiving portion 117 of the movable drive pulley 110 . The rotational driving force (back torque) thus transmitted to the ramp plate 130 is transmitted to the crankshaft 90 .

As described above, according to the continuously variable transmission 100 of the present embodiment, the movable drive pulley 110 is formed on the outer peripheral wall 118 located radially outside the center cylindrical portion 111 and A first recess 118D recessed in the first direction D1 from the end face 118T in the second direction D2 of the portion defining the accommodation portion 113 that accommodates the weight 120, and communicating with the first recess 118D and communicating with the first recess 118D. and an internal space 118S positioned radially inward of the inner space 118S. Therefore, air flows into the internal space 118S through the first recess 118D formed in the outer peripheral wall 118, and the air in the internal space 118S is discharged to the outside. That is, the heated air remaining in the internal space 118S is discharged to the outside of the movable drive pulley 110, and the external air flows into the internal space 118S, thereby cooling the internal space 118S. This cools the movable drive pulley 110 . Here, since the first recess 118D is recessed in the first direction D1 from the end face 118T in the second direction D2 of the portion of the outer peripheral wall 118 that defines the accommodation portion 113, the fixed drive pulley 110 is more likely to be driven than the movable drive pulley 110. It is possible to cool the portion on the pulley 102 side (for example, the vicinity of the sliding surface on which the V-belt 140 slides).

Further, according to the continuously variable transmission 100 of the present embodiment, the ramp plate 130 is positioned on the second direction D2 side of the internal space 118S, and is located in the internal space 118S when viewed from the axial direction of the crankshaft 90. overlap with the part.

In the continuously variable transmission 100 of the present embodiment, the movable drive pulley 110 includes a plurality of housing portions 113 arranged in the rotation direction L and a plurality of first recesses positioned between the housing portions 113 adjacent to each other in the rotation direction L. 118D and an internal space 118S. According to the above-described aspect, air can be exchanged between the internal space 118S and the outside over a wide range of the movable drive pulley 110, so that the movable drive pulley 110 can be further cooled.

In the continuously variable transmission 100 of the present embodiment, the internal space 118S is positioned between the side wall 119 that defines one of the adjacent housing portions 113 and the side wall 119 that defines the other housing portion 113. . According to the aspect described above, the housing portion 113 can be cooled via the side wall 119 .

In the continuously variable transmission 100 of the present embodiment, the side walls 119 partitioning the plurality of accommodating portions 113 are connected to the center tubular portion 111 respectively. According to the above aspect, since the center tubular portion 111 and the side wall 119 are connected, the rigidity of the movable drive pulley 110 is high.

In the continuously variable transmission 100 of the present embodiment, the end face 111T of the center tube portion 111 in the second direction D2, the end face 119T of the side wall 119 in the second direction D2, and the end face of the outer peripheral wall 118 in the second direction D2 It is formed flush with 118T. According to the above aspect, the weight 120 housed in the housing portion 113 can be held more reliably.

In the continuously variable transmission 100 of the present embodiment, the movable drive pulley 110 is formed on the outer peripheral wall 118, positioned radially outward of the accommodating portion 113, and recessed radially inward. It has two recesses 118H. According to the above aspect, external air also flows into the second recess 118H, so that the movable drive pulley 110 can be further cooled.

The preferred embodiment of the present invention has been described above. However, the above-described embodiments are merely examples, and the present invention can be embodied in various other forms.

In the above-described embodiment, the weight 120 includes the weight body 121 made of metal and the body cover 122 made of resin. However, the weight 120 may be integrally formed from a single material, or may be formed from three or more kinds of materials. Also, the body cover 122 may be made of metal.

In the above-described embodiment, the first sliding surface 122a of the weight 120 was curved. However, the first sliding surface 122a may be a flat surface as long as it can slide (including rolling) on the movable drive pulley-side weight sliding surface 114 .

In the above-described embodiment, the second sliding surface 122b of the weight 120 was flat. However, the second sliding surface 122b may be a curved surface as long as it can slide (including rolling) on the ramp-side weight sliding surface 132 . For example, by forming the first sliding surface 122a and the second sliding surface 122b of the weight 120 into curved surfaces, the weight 120 rolls on the movable drive pulley-side weight sliding surface 114 and the ramp-side weight sliding surface 132. can be configured as

In the above-described embodiment, the ramp plate 130 is integrally formed by connecting the ramp-side weight sliding surface 132 and the ramp-side protruding piece 133 . Thereby, the rigidity of the lamp-side projecting piece 133 projecting from the disk portion 131 can be improved. However, the lamp-side weight sliding surface 132 and the lamp-side protruding piece 133 may be formed at positions separated from each other.

In the above-described embodiment, the projecting piece accommodating portion 116 is formed into a square box shape in plan view by the weight side end surface 116a, the outer surface 116b, the inner surface 116c, and the projecting piece receiving portion 117. As a result, foreign matter can be prevented from entering the projecting piece accommodating portion 116 from the outside, and the rigidity of the projecting piece receiving portion 117 can be improved. However, the movable drive pulley 110 can also be configured without the projecting piece accommodating portion 116 . For example, the outer side surface 116b and the inner side surface 116c of the protruding piece accommodating portion 116 may be omitted, and the protruding piece receiving portion 117 may be provided with a thickness equal to or greater than the thickness of the lamp side protruding piece 133 with respect to the end portion of the movable drive pulley side weight sliding surface 114. It is good to provide it through a gap. According to this, ventilation is ensured between the lamp-side projecting piece 133 and the projecting piece receiving portion 117 and between the lamp-side projecting piece 133 and the second end portion 122d of the weight 120, thereby suppressing overheating. can do.

In the above-described embodiment, the movable drive pulley 110 is integrally formed by connecting the movable drive pulley-side weight sliding surface 114 and the weight receiving portion 115 . Thereby, the rigidity of the weight receiving portion 115 projecting from the conical portion 112 can be improved. However, the movable drive pulley side weight sliding surface 114 and the weight receiving portion 115 may be formed at positions separated from each other.

In the above-described embodiment, the movable drive pulley 110 has three movable drive pulley-side weight sliding surfaces 114 and three protruding piece receiving portions 117 (that is, three sets). However, the movable drive pulley 110 only needs to have at least one movable drive pulley-side weight sliding surface 114 and at least one projecting piece receiving portion 117 . In this case, the ramp-side weight sliding surfaces 132 and the ramp-side protruding pieces 133 are formed according to the number of the movable drive pulley-side weight sliding surfaces 114 and the protruding piece receiving portions 117 formed.

When a plurality of movable drive pulley-side weight sliding surfaces 114 and projecting piece receiving portions 117 are provided (that is, when a plurality of sets are provided), they are arranged at equal intervals in the rotational direction L of the movable drive pulley 110, They may be arranged at uneven intervals along the direction L, or may be formed at different positions in the radial direction of the movable drive pulley 110 .

In the above-described embodiment, the movable drive pulley-side weight sliding surface 114 had the flat surface portion 114a and the curved surface portion 114b. However, the movable drive pulley side weight sliding surface 114 may have only one of the flat portion 114a and the curved portion 114b.

In the above-described embodiment, the ramp-side weight sliding surface 132 has the ramp-side planar portion 132a formed in a planar shape. However, the ramp-side weight sliding surface 132 may have a curved surface portion.

In the above-described embodiment, the radial length of the protruding piece accommodating portion 116 is longer than the radial length of the movable drive pulley-side weight sliding surface 114, but is not limited to this. For example, as shown in FIG. 17, the radial length of the protruding piece accommodating portion 116 and the radial length of the movable drive pulley-side weight sliding surface 114 may be the same.

In the above-described embodiment, when the weight 120 is positioned radially inward, the ramp plate 130 is configured to partially overlap the internal space 118S when viewed from the axial direction of the crankshaft 90. The plate 130 may not overlap the internal space 118S.

In the above-described embodiment, the engine is used as the power source, but the power source is not limited to the engine, and may be an electric motor or the like.

The straddle-type vehicle in this embodiment is a vehicle that the driver rides on. Straddle-type vehicles are not limited to motorcycles such as scooters. The straddle-type vehicle may be, for example, a tricycle, an ATV (All Terrain Vehicle), a snowmobile, or the like.

90 Crankshaft 100 Continuously variable transmission 101 Drive pulley 102 Fixed drive pulley 110 Movable drive pulley 110C Rotation center 111 Center cylindrical portion 113 Accommodating portion 114 Movable drive pulley side weight sliding surface 114a Flat portion 114b Curved surface portion 115 Weight receiving portion 116 Projection Piece accommodating portion 117 Protruding piece receiving portion 118 Peripheral wall 118D First recess (recess)
118H Second recess (other recess)
118S Internal space 118T End face in second direction (end in second direction)
119 side wall 120 weight 121 weight main body 122 main body cover (contact portion)
122a First sliding surface 122b Second sliding surface (weight-side flat portion)
122c first end (first surface)
122d second end (second surface)
130 Ramp plate 132 Ramp-side weight sliding surface 132a Ramp-side flat portion 133 Ramp-side protruding piece 140 V-belt C1 Circle C2 Normal line C3 Center line L Rotational direction

Claims

A fixed drive pulley that rotates integrally with a crankshaft that is driven to rotate by a power source, and a movable drive pulley that is arranged opposite to the fixed drive pulley and moves toward or away from the fixed drive pulley on the crankshaft. and a drive pulley having
a ramp plate disposed on the side opposite to the fixed drive pulley with respect to the movable drive pulley and driven to rotate integrally with the crankshaft;
a weight sandwiched between the movable drive pulley and the ramp plate and movable in the radial direction of the movable drive pulley;
The weight moves from the radially inner position to the radially outer position to press the movable drive pulley due to the centrifugal force caused by the rotation of the movable drive pulley, thereby moving the movable drive pulley to the fixed drive. configured to approach the pulley;
The movable drive pulley is
a center tubular portion that slides along the crankshaft;
an outer peripheral wall located outside the center tubular portion in the radial direction;
a housing portion formed between the center tubular portion and the outer peripheral wall, housing the weight, and partly partitioned by the outer peripheral wall;
When the direction in which the movable drive pulley moves away from the ramp plate is defined as a first direction, and the direction in which the movable drive pulley approaches the ramp plate is defined as a second direction, a a recess that is recessed in the first direction from the end in the second direction of the portion that defines the housing portion of
a continuously variable transmission, comprising: an internal space that communicates with the recess and is located inside the recess in the radial direction.
A fixed drive pulley that rotates integrally with a crankshaft that is driven to rotate by a power source, and a movable drive pulley that is arranged opposite to the fixed drive pulley and moves toward or away from the fixed drive pulley on the crankshaft. and a drive pulley having
a ramp plate disposed on the side opposite to the fixed drive pulley with respect to the movable drive pulley and driven to rotate integrally with the crankshaft;
a weight sandwiched between the movable drive pulley and the ramp plate and movable in the radial direction of the movable drive pulley;
The weight moves from the radially inner position to the radially outer position to press the movable drive pulley due to the centrifugal force caused by the rotation of the movable drive pulley, thereby moving the movable drive pulley to the fixed drive. configured to approach the pulley;
The movable drive pulley is
a center tubular portion that slides along the crankshaft;
an outer peripheral wall located outside the center tubular portion in the radial direction;
a housing portion formed between the center tubular portion and the outer peripheral wall, housing the weight, and partly partitioned by the outer peripheral wall;
When the direction in which the movable drive pulley moves away from the ramp plate is defined as a first direction, and the direction in which the movable drive pulley approaches the ramp plate is defined as a second direction, a a recess recessed in the direction of
an internal space that communicates with the recess and is located inside the recess in the radial direction,
When the weight is positioned on the inner side in the radial direction, the ramp plate is positioned on the second direction side of the internal space, and is located in the internal space when viewed from the axial direction of the crankshaft. Continuously variable transmission that overlaps with a part.
The movable drive pulley is
a plurality of housing portions arranged in the direction of rotation when the direction of rotation of the fixed drive pulley, the movable drive pulley, and the ramp plate is defined as the direction of rotation;
3. The continuously variable transmission according to claim 1, further comprising a plurality of said recesses and said internal spaces respectively positioned between said accommodating parts adjacent to each other in said rotation direction.
the movable drive pulley includes a pair of side walls extending in a direction intersecting the rotational direction when viewed from the axial direction of the crankshaft and partitioning the accommodating portion;
4. The continuously variable transmission according to claim 3, wherein the internal space is positioned between the side wall that defines one of the adjacent housing portions and the side wall that defines the other of the adjacent housing portions. .
The continuously variable transmission according to claim 4, wherein the side walls that partition the plurality of housing portions are each connected to the center tubular portion.
6. The end surface of the center tubular portion in the second direction, the end surface of the side wall in the second direction, and the end surface of the outer peripheral wall in the second direction are formed flush with each other. The continuously variable transmission described in .
The movable drive pulley is
3. The recess according to claim 1, further comprising another recess formed in the outer peripheral wall, located outside the accommodation portion in the radial direction, and recessed inward in the radial direction. Continuously variable transmission.