JP2011089559A - Continuously variable transmission and saddle riding type vehicle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a continuously variable transmission for suppressing the discomfort feeling of a rider due to stick slip noises, and to provide a saddle riding type vehicle. <P>SOLUTION: The continuously variable transmission includes a driving shaft, a driving side pulley, a driven shaft, a driven side pulley, and a V-belt. The driving side pulley is provided on the driving shaft. The driven shaft is arranged apart form the driving shaft. The driven side pulley is provided on the driven shaft. The V-belt has a plurality of resin blocks 52 and a connection member 53, and is wound on the driving side pulley and the driven side pulley. The plurality of resin blocks 52 are provided on portions contacting at least the driving side pulley and the driven side pulley. The connection member 53 is an endless member for connecting the plurality of resin blocks 52 to one another. Friction force which is applied to a portion located on the lower side of each resin block 52 through the driven side pulley is greater than friction force which is applied to a portion located on the upper side of each resin block 52 through the driven side pulley. <P>COPYRIGHT: (C)2011,JPO&amp;INPIT

Description

  The present invention relates to a continuously variable transmission and a saddle type vehicle.

  In a belt-type continuously variable transmission, a V-belt is wound around a driving pulley and a driven pulley. In some belt-type continuously variable transmissions, a portion of the V-belt that contacts each pulley is configured by a plurality of resin blocks, and the plurality of resin blocks are connected by a connecting member.

  For example, in the continuously variable transmission disclosed in Patent Document 1, a plurality of resin blocks are connected to the V belt by an endless connecting body. The V belt is wound around the primary sheave and the secondary sheave.

JP 2008-39177 A

  When the V-belt is constituted by a plurality of resin blocks as in the continuously variable transmission described above, stick-slip noise is likely to occur when the resin block sandwiched between the pulleys comes off the pulley. This stick-slip sound may make the rider feel uncomfortable.

  As a result of research, the inventor of the present application has found the cause of this stick-slip sound as follows.

  The resin block moves by being pulled by the connecting member. Then, power is transmitted to the driven pulley by friction between the side surface of the resin block and the surface of the driven pulley. Here, immediately before the resin block comes out of the driven pulley, the resin block is pulled by the connecting member in the advancing direction of the connecting member (see arrow A1 in FIG. 8). However, the side surface of the resin block is caught in the rotation of the driven pulley by friction with the surface of the driven pulley (see arrow A2 in FIG. 8). For this reason, deformation occurs in the resin block. When the resin block comes out of the driven pulley and is released from the driven pulley, the resin block is instantaneously returned from the deformed state by being wound around the surface of the driven pulley. At this time, a stick-slip sound is generated by the friction of the side surface of the resin block with the surface of the driven pulley. Note that this stick-slip sound is generated every time a plurality of resin blocks come out of the pulley, so that it is repeatedly generated when the V-belt is driven.

  An object of the present invention is to provide a continuously variable transmission and a straddle-type vehicle capable of suppressing rider discomfort due to stick-slip noise.

  A continuously variable transmission according to the present invention includes a drive shaft, a drive side pulley, a driven shaft, a driven side pulley, and a V-belt. The driving pulley is provided on the driving shaft. The driven shaft is disposed away from the driving shaft. The driven pulley is provided on the driven shaft. The V belt has a plurality of resin blocks and a connecting member, and is wound around a driving pulley and a driven pulley. The plurality of resin blocks are provided at least in contact with the driving pulley and the driven pulley. The connecting member is an endless member that connects a plurality of resin blocks. The friction force applied from the driven pulley to the portion of the resin block located on the small diameter side of the driven pulley is from the driven pulley on the portion of the resin block located on the large diameter side of the driven pulley. It is larger than the applied friction.

  In the present invention, the frictional force applied to the portion of the resin block located on the smaller diameter side of the driven pulley is greater than the frictional force applied to the portion of the resin block located on the larger diameter side of the driven pulley. Yes. Accordingly, when the resin block is pulled out of the driven pulley by being pulled by the connecting member, the resin block is positioned so that the portion located on the large diameter side is located closer to the traveling direction side of the connecting member than the portion located on the small diameter side. In addition, the posture is inclined. For this reason, compared with the case where it is a perpendicular | vertical attitude | position with respect to the advancing direction, a resin block becomes easy to move toward the advancing direction of a connection member. Thereby, generation | occurrence | production of the stick slip sound at the time of a resin block pulling out from a driven pulley can be suppressed.

1 is a side view of a motorcycle according to an embodiment of the present invention. Sectional drawing of the engine unit with which a motorcycle is equipped. The figure which shows the speed change operation | movement in a continuously variable transmission. The side view of a V belt. The side view of a resin block, and IV-IV sectional drawing of the V belt in FIG. Sectional drawing which shows the driven pulley and V belt when the winding diameter of V belt is the maximum. The schematic diagram which shows the resin block at the time of pulling out from the driven pulley in the continuously variable transmission which concerns on this embodiment. The schematic diagram which shows the resin block at the time of pulling out from the driven pulley in the conventional continuously variable transmission. Sectional drawing of the V belt which concerns on other embodiment. Sectional drawing of the V belt which concerns on other embodiment. The side view of the resin block which concerns on other embodiment, and sectional drawing of a V belt. The side view of the resin block which concerns on other embodiment, and sectional drawing of a V belt. The side view of the resin block which concerns on other embodiment, and sectional drawing of a V belt. Sectional drawing of the V belt which concerns on other embodiment. Sectional drawing of the V belt which concerns on other embodiment. Sectional drawing of the V belt which concerns on other embodiment. Sectional drawing of the V belt which concerns on other embodiment.

  Hereinafter, an embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a side view of a motorcycle 1 according to an embodiment of the present invention. In the following description, the front-rear and left-right directions refer to the front-rear, left-right directions as viewed from the rider seated on the seat 9 of the motorcycle 1 unless otherwise specified.

<Overall configuration>
As shown in FIG. 1, the motorcycle 1 includes a body frame 2, an engine unit 10, a front wheel 3, and a rear wheel 4.

  The vehicle body frame 2 includes a head pipe 2a, a main frame 2b, a seat rail 2c, a stay 2d, and a bracket 2e. The head pipe 2 a is provided at the front end portion of the vehicle body frame 2. The head pipe 2a supports the steering shaft 6 so as to be rotatable. A handle 5 is connected to the upper end of the steering shaft 6, and the steering shaft 6 rotates together with the handle 5. A front fork 7 is connected to the lower end portion of the steering shaft 6, and the lower end portion of the front fork 7 supports the front wheel 3 in a rotatable manner.

  The front end of the main frame 2b is connected to the head pipe 2a. The main frame 2b extends obliquely downward from its front end toward the rear of the vehicle body. The rear end portion of the main frame 2 b is located in front of the rear wheel 4. A front end portion of the seat rail 2c is connected to an intermediate portion of the main frame 2b. The seat rail 2c extends obliquely upward from the front end portion toward the rear portion of the vehicle body. A storage case 8 and a seat 9 are disposed above the seat rail 2 c, and the seat rail 2 c supports the storage case 8 and the seat 9. The front end of the stay 2d is connected to the rear end of the main frame 2b. The stay 2d extends obliquely upward from the front end portion toward the rear portion of the vehicle body. An upper end portion of the stay 2d is connected to an intermediate portion of the seat rail 2c.

  The bracket 2e is a plate-like member and is joined to the rear end portion of the main frame 2b. A front end portion of the rear arm 11 is attached to the upper portion of the bracket 2 e via a pivot shaft 12. The rear arm 11 extends rearward from the pivot shaft 12 (the direction opposite to the direction indicated by Fr in FIG. 1). The rear end portion of the rear arm 11 supports the rear wheel 4 in a rotatable manner. The rear arm 11 swings up and down with the rear wheel 4 with the pivot shaft 12 as a fulcrum, and swings independently with respect to the engine unit 10.

  The engine unit 10 is supported by the body frame 2. The engine unit 10 is disposed below the main frame 2b and in front of the rear wheel 4. As shown in FIG. 2, the engine unit 10 includes an engine 20, a driven shaft 27, an output shaft 29, a continuously variable transmission 30 (hereinafter referred to as “CVT30”), and a clutch 80. Yes.

  The engine 20 includes a crankshaft 21 (drive shaft), a cylinder 22, a piston 23, and a crankcase 60. The cylinder 22 is disposed in front of the crankcase 60 (the direction indicated by Fr in FIG. 2). The cylinder 22 is arranged in a posture in which the front side is slightly inclined upward. The piston 23 reciprocates in the cylinder 22 as a mixture of fuel and air sent into the cylinder 22 burns. The piston 23 is connected to a crankpin 25 provided on the crankshaft 21 via a connecting rod 24. The reciprocating motion of the piston 23 is converted into rotational motion by the crankshaft 21 and output to the CVT 30.

  The crankshaft 21 is disposed in the crankcase 60 along the vehicle width direction (the direction indicated by W in FIG. 2). The crankshaft 21 has a right shaft portion 21a, a left shaft portion 21b, and a pair of crank arms 21c and 21c. The crank arms 21c and 21c extend in a radial direction (a direction perpendicular to the shaft center line) from the base portions of the right shaft portion 21a and the left shaft portion 21b, and rotatably support the crank pin 25.

  A base portion of the left shaft portion 21 b is supported by the crankcase 60 via a bearing 69. The left shaft portion 21b extends from the base portion to the left side (upper side in FIG. 2). A generator (not shown) is provided on the left shaft portion 21b.

  A base portion of the right shaft portion 21 a is supported by the crankcase 60 via a bearing 68. The right shaft portion 21a extends from the base portion to the right side (lower side in the drawing of FIG. 2). A drive pulley 31 of the CVT 30 is provided on the right shaft 21a. An end 21d of the right shaft 21a is supported by a transmission case 50 described later.

  The driven shaft 27 is disposed at a position separated rearward from the crankshaft 21. The driven shaft 27 is disposed along the vehicle width direction. On the driven shaft 27, a driven pulley 41 of the CVT 30 described later and a clutch 80 are provided. A right end 27 a of the driven shaft 27 is supported by the transmission case 50. A bearing 65 and a bearing 63 are fitted to the left end 27 b of the driven shaft 27. The outer ring of the bearing 65 is supported by the crankcase 60, and the crankcase 60 supports the end portion 27 b of the driven shaft 27 via the bearing 65. The bearing 63 is located on the left side of the bearing 65.

  A bearing 66 is fitted in the central portion 27 c of the driven shaft 27. The outer ring of the bearing 66 is supported by a partition member 64 fixed to the crankcase 60. The crankcase 60 supports the central portion of the driven shaft 27 via a partition member 64 and a bearing 66.

  The output shaft 29 is arranged side by side with the driven shaft 27 in the vehicle width direction. The output shaft 29 is located on the left side of the driven shaft 27. The output shaft 29 is fitted on the outer ring of the bearing 63, and the bearing 63 supports the output shaft 29. A central portion 29 a of the output shaft 29 is supported by the crankcase 60 via a bearing 62. On the output shaft 29, a sprocket 29c around which a chain (not shown) is wound is provided.

  The CVT 30 is a belt type continuously variable transmission, and includes a driving pulley 31, a driven pulley 41, a V belt 39, and a transmission case 50.

  The driving pulley 31 is provided on the right shaft portion 21 a of the crankshaft 21. The driving pulley 31 has a fixed pulley body 32, a movable pulley body 33, and a plate 35. The axial movement of the fixed pulley body 32 and the plate 35 is restricted. The movable pulley body 33 is allowed to move in the axial direction between the fixed pulley body 32 and the plate 35. The movable pulley body 33 is arranged facing the fixed pulley body 32 in the axial direction. A belt groove in which the V belt 39 is disposed is formed between the movable pulley body 33 and the fixed pulley body 32, and the front side of the V belt 39 is wound around the movable pulley body 33 and the fixed pulley body 32. It has been. The surfaces of the movable pulley body 33 and the fixed pulley body 32 that come into contact with the V-belt 39 so that the width of the belt groove increases toward the larger diameter side of the driving pulley 31 are the radial direction of the driving pulley 31 (the driving pulley). It is a shape that is inclined with respect to the direction perpendicular to the axis 31.

  Between the movable pulley body 33 and the plate 35, a weight roller 34 that moves in the radial direction by centrifugal force is disposed. When the crankshaft 21 rotates, the weight roller 34 moves to the larger diameter side and presses the movable pulley body 33 toward the fixed pulley body 32 side. Then, the V belt 39 is pushed by the movable pulley body 33 and moves to the large diameter side of the driving pulley 31, and the diameter of the portion of the V belt 39 wound around the driving pulley 31 (hereinafter referred to as “winding diameter”). The reduction ratio becomes smaller.

  As shown in FIG. 2, the driven pulley 41 is located behind the driving pulley 31. The driven pulley 41 is provided on the driven shaft 27 and rotates together with the driven shaft 27 by torque transmitted through the V belt 39. The driven pulley 41 has a fixed pulley body 42 and a movable pulley body 43.

  The fixed pulley body 42 is restricted from moving in the axial direction. The fixed pulley body 42 is coupled to the driven shaft 27 by a spline, and rotates integrally with the driven shaft 27. The fixed pulley body 42 has a larger diameter than the fixed pulley body 32 of the driving pulley 31.

  The movable pulley body 43 is provided so as to be movable in the axial direction. Further, the movable pulley body 43 rotates together with the driven shaft 27. The movable pulley body 43 is disposed so as to face the fixed pulley body 42 in the axial direction. A belt groove in which the V belt 39 is disposed is formed between the movable pulley body 43 and the fixed pulley body 42, and the rear side of the V belt 39 is wound around the movable pulley body 43 and the fixed pulley body 42. It has been. As shown in FIG. 6, the surface of the fixed pulley body 42 that contacts the V belt 39 (hereinafter referred to as “first surface 46”) and the surface of the movable pulley body 43 that contacts the V belt 39 (hereinafter referred to as “first surface 46”). 2 surface 47 ") is arranged so as to face the V-belt 39, and constitutes the belt groove. The first surface 46 and the second surface 47 are inclined with respect to the radial direction of the driven pulley 41 (direction perpendicular to the axis of the driven pulley 41). The first surface 46 and the second surface 47 are inclined at a predetermined sandwich angle so that the distance between the first surface 46 and the second surface 47 increases toward the larger diameter side. Thereby, the width of the belt groove is increased toward the larger diameter side of the driven pulley 41. As shown in FIG. 2, the movable pulley body 43 has a larger diameter than the movable pulley body 33 of the driving pulley 31.

  A spring support member 45 is disposed on the right side of the movable pulley body 43. The spring support member 45 is a disk-shaped member and rotates together with the driven shaft 27. A spring 44 is provided between the spring support member 45 and the movable pulley body 43. The spring support member 45 is restricted from moving in the axial direction and supports the spring 44. When the movable pulley body 33 increases the winding diameter of the V belt 39 in the driving pulley 31, the movable pulley body 43 in the driven pulley 41 moves away from the fixed pulley body 42 against the biasing force of the spring 44. Move in the direction. As a result, the winding diameter of the V belt 39 of the driven pulley 41 is reduced, and the reduction ratio is reduced.

  The transmission case 50 accommodates the driving pulley 31, the driven pulley 41, and the V belt 39 inside. The transmission case 50 is provided with an intake port 51c for taking in outside air and an exhaust port 51d for discharging the air in the transmission case 50. An intake duct 71 is attached to the intake port 51c. Outside air is taken in from the duct tip 73 (see FIG. 1), purified by the air cleaner 72 (see FIG. 1), and then introduced into the transmission case 50 through the intake duct 71 and the intake port 51c. An exhaust duct 74 (see FIG. 1) is connected to the exhaust port 51d, and the air in the transmission case 50 is discharged to the outside through the exhaust port 51d and the exhaust duct 74.

  The clutch 80 transmits or blocks the torque transmitted from the driven shaft 27 to the output shaft 29 side. The clutch 80 is disposed on the left side of the driven pulley 41. The clutch 80 includes a clutch outer 82, a clutch inner 81, a plurality of friction plates 83, and a plurality of clutch plates 84.

  The clutch outer 82 is provided so as to rotate together with the driven shaft 27. The clutch inner 81 is provided so as to idle with respect to the driven shaft 27. A gear 26 that idles with respect to the driven shaft 27 is provided on the driven shaft 27, and the clutch inner 81 rotates together with the gear 26.

  The friction plate 83 and the clutch plate 84 are disk-shaped members, and are arranged inside the clutch outer 82 so as to surround the clutch inner 81. The friction plates 83 and the clutch plates 84 are alternately arranged in the axial direction. The friction plate 83 is provided so as to be movable in the axial direction. The friction plate 83 is provided so as to rotate around the driven shaft 27 together with the clutch outer 82. The inner peripheral surface of the clutch inner 81 is engaged with the gear 26. The clutch plate 84 is provided so as to be movable in the axial direction. The clutch plate 84 is provided so as to rotate together with the clutch inner 81.

  The plurality of friction plates 83 and the plurality of clutch plates 84 are pressed against each other and interlocked so that torque is transmitted from the friction plates 83 to the clutch plates 84. The clutch 80 is an automatic clutch, and the connection or disconnection of the clutch 80 is automatically performed according to the rotational speed of the driven shaft 27. Specifically, the clutch 80 includes a weight roller 86 and a diaphragm spring 85. The weight roller 86 rotates around the driven shaft 27 together with the clutch outer 82. The diaphragm spring 85 biases the friction plate 83 in the axial direction. The plurality of friction plates 83 and the plurality of clutch plates 84 are disposed between the weight roller 86 and the diaphragm spring 85. When the rotational speed of the driven shaft 27 increases and the rotational speed of the clutch outer 82 increases, the weight roller 86 moves to the larger diameter side (radially outward) by the centrifugal force and presses the friction plate 83 against the clutch plate 84. . As a result, the clutch 80 is in a connected state. Further, when the rotational speed of the driven shaft 27 decreases, the weight roller 86 returns to the small diameter side (inside in the radial direction), the friction plate 83 is separated from the clutch plate 84, and the clutch 80 is in a disconnected state.

  The rotation of the crankshaft 21 is decelerated by the CVT 30 and transmitted to the driven shaft 27. When the clutch 80 is in the connected state, the rotation of the driven shaft 27 is transmitted to the gear 26 via the clutch 80. The gear 26 meshes with a gear 28 a of an intermediate shaft 28 disposed in front of the driven shaft 27. Further, a gear 28 b is formed on the intermediate shaft 28, and the gear 28 b meshes with a gear 29 b formed on the output shaft 29. As a result, the rotation of the gear 26 is transmitted to the output shaft 29 via the intermediate shaft 28. The rotation of the output shaft 29 is transmitted to the rear wheel 4 through a chain wound around the sprocket 29c and a sprocket (not shown) that rotates with the rear wheel 4.

  As shown in FIGS. 2 and 3, the V-belt 39 is wound around the driving pulley 31 and the driven pulley 41, and transmits torque from the driving pulley 31 to the driven pulley 41. The configuration of the V belt 39 will be described in detail later.

<Operation of CVT 30>
Hereinafter, the operation of the CVT 30 will be described mainly based on FIG. 2 and FIG.

  In the CVT 30, the reduction ratio is determined by the magnitude relationship between the force by which the weight roller 34 pushes the movable pulley body 33 of the driving pulley 31 to the right and the force of the spring 44 pushing the movable pulley body 43 of the driven pulley 41 to the left. It is determined.

  That is, when the rotation speed of the crankshaft 21 increases, the weight roller 34 receives the centrifugal force and moves to the larger diameter side, and pushes the movable pulley body 33 rightward. Then, the movable pulley body 33 moves to the right side, and the winding diameter of the V belt 39 on the driving pulley 31 is increased. Along with this, the winding diameter of the V-belt 39 on the driven pulley 41 decreases, and the movable pulley body 43 of the driven pulley 41 moves to the right against the urging force of the spring 44. As a result, the winding diameter of the V-belt 39 in the driving pulley 31 increases, while the winding diameter in the driven pulley 41 decreases and the reduction ratio decreases (see FIG. 3B).

  On the other hand, when the rotational speed of the crankshaft 21 decreases, the centrifugal force of the weight roller 34 decreases, so that the weight roller 34 moves along the movable pulley body 33 to the smaller diameter side. For this reason, the force with which the weight roller 34 pushes the movable pulley body 33 to the right is reduced. Then, the urging force of the spring 44 is relatively larger than the above-mentioned force by the weight roller 34, the movable pulley body 43 of the driven pulley 41 moves to the left side, and the movable pulley body 33 of the driving pulley 31 is also correspondingly moved. Move to the left. As a result, the winding diameter of the V belt 39 in the driving pulley 31 is reduced, while the winding diameter of the V belt 39 in the driven pulley 41 is increased, and the reduction ratio is increased (see FIG. 3A). .

  Accordingly, when the CVT 30 is at the lowest speed, that is, in the idling state, the winding diameter of the V belt 39 on the driven pulley 41 is maximized and the V belt 39 on the driving pulley 31 is shown in FIG. The winding diameter is minimum. This maximizes the reduction ratio. When the CVT 30 is at the highest speed, the winding diameter of the V belt 39 on the driven pulley 41 is minimized and the winding of the V belt 39 on the driving pulley 31 is performed as shown in FIG. The diameter becomes the maximum. This minimizes the reduction ratio.

<Configuration of V-belt 39>
As shown in FIGS. 4 and 5, the V-belt 39 includes a plurality of resin blocks 52 and a connecting member 53. In the following description of the resin block 52, “upper and lower” means that the resin block 52 is an upper side of two linear portions located between the driving pulley 31 and the driven pulley 41 in the endless V belt 39. It means the up and down in the state (refer to position P1 in FIG. 3) located in the straight line portion. Therefore, in a state where the resin block 52 is positioned at a portion wound around the driven pulley 41, “upper” corresponds to the large diameter side of the driven pulley 41, and “lower” corresponds to the driven side. This corresponds to the small diameter side of the pulley 41. Furthermore, in other words, “upper” corresponds to the outer peripheral side of the V-belt 39, and “lower” corresponds to the inner peripheral side of the V-belt 39.

  The plurality of resin blocks 52 are arranged side by side along the longitudinal direction of the connecting member 53. The resin block 52 is provided in a portion that contacts the driving pulley 31 and the driven pulley 41. In addition, on both the left and right side surfaces of the resin block 52, concave portions 54 that are recessed inward are formed. A connecting member 53 is fitted in the recess 54. FIG. 5A shows the side surface of the resin block 52, and the connecting member 53 is not shown. As shown in FIG. 5A, the lower inner surface 54a of the concave portion 54 has a shape that is convexly convex toward the upper side. Further, the upper surface 54b of the recess 54 is provided with a protrusion 54c whose central portion protrudes downward. In FIG. 5A, only one of the left and right side surfaces of the resin block 52 is shown, but the other side surface has the same structure.

  As shown in FIG. 5B, the resin block 52 has an outer block portion 52a and an inner block portion 52b. The outer block portion 52 a is a portion located on the upper side with respect to the connecting member 53. The inner block portion 52 b is a portion located on the lower side with respect to the connecting member 53.

  The inner block portion 52b has a first inner side surface 56a and a second inner side surface 56b. As shown in FIG. 6, the first inner side surface 56 a faces the first surface 46 of the driven pulley 41 described above and contacts the first surface 46. The first inner side surface 56 a is inclined corresponding to the inclination of the first surface 46. The second inner side surface 56 b faces the second surface 47 of the driven pulley 41 described above and contacts the second surface 47. The second inner side surface 56 b is inclined corresponding to the inclination of the second surface 47.

  The outer block 52a has a first outer side surface 57a and a second outer side surface 57b. The first outer side surface 57 a faces the first surface 46. The second outer side surface 57 b faces the second surface 47. Moreover, as shown in FIG.5 (b), the clearance gap is provided between the whole 1st outer side surface 57a and the 1st virtual extension surface 58a. The first virtual extended surface 58a is a virtual plane including the first inner side surface 56a, and is inclined at the same angle as the first inner side surface 56a. Further, a gap is provided between the entire second outer side surface 57b and the second virtual extension surface 58b. The second virtual extended surface 58b is a virtual plane including the second inner side surface 56b, and is inclined at the same angle as the second inner side surface 56b. Therefore, as shown in FIG. 6, in a state where the resin block 52 is sandwiched between the fixed pulley body 42 and the movable pulley body 43 of the driven pulley 41, the first outer side surface 57 a is the first surface of the fixed pulley body 42. 46 and no contact. The second outer side surface 57 b is not in contact with the second surface 47 of the movable pulley body 43. FIG. 6 is a cross-sectional view of the driven pulley 41 and the V belt 39 in a plane passing through the central axis of the driven pulley 41. For ease of understanding, hatching is omitted from the driven pulley 41 and the resin block 52 in FIG. FIG. 6 shows a part of the driven pulley 41 and the V belt 39 when the winding diameter of the V belt 39 at the driven pulley 41 is maximized. However, even when the winding diameter of the V belt 39 at the driven pulley 41 is not maximum, the first outer side surface 57a is not in contact with the first surface 46 of the fixed pulley body 42, and the second outer side surface 57b is The movable pulley body 43 is not in contact with the second surface 47.

  The connecting member 53 connects a plurality of resin blocks 52. The connecting member 53 is disposed at a substantially central position in the vertical direction in the resin block 52. The connection member 53 has connection bodies 53a and 53b formed separately from each other. The coupling bodies 53a and 53b are each formed in an endless shape. As shown in FIG. 5B, the coupling bodies 53 a and 53 b are fitted in the recesses 54 of the respective resin blocks 52. As described above, the coupling bodies 53a and 53b are fitted into the recesses 54 of the resin block 52, whereby the plurality of resin blocks 52 are coupled to each other via the coupling bodies 53a and 53b. The coupling bodies 53a and 53b are made of rubber. In addition, a plurality of reinforcing core wires 55 are embedded in the coupling bodies 53a and 53b, respectively.

<Features>
In the motorcycle 1 and the CVT 30 according to the present embodiment, the first outer side surface 57a of the outer block portion 52a is not in contact with the first surface 46 of the fixed pulley body 42. Further, the second outer side surface 57 b of the outer block portion 52 a is not in contact with the second surface 47 of the movable pulley body 43. For this reason, the frictional force applied from the driven pulley 41 to the inner block portion 52b is larger than the frictional force applied from the driven pulley 41 to the outer block portion 52a. That is, the frictional force applied to the lower portion of the resin block 52 is greater than the frictional force applied to the upper portion of the resin block 52. Accordingly, as shown in FIG. 7, when the resin block 52 is pulled out from the driven pulley 41, the portion located on the upper side is closer to the traveling direction side of the connecting member 53 than the portion located on the lower side (see arrow A <b> 1). It is in an inclined posture so as to be located at For this reason, the resin block 52 is easily pulled out from the driven pulley 41 in the traveling direction as compared with the case where the posture is perpendicular to the traveling direction (see FIG. 8). Thereby, it is possible to suppress the occurrence of stick-slip noise when the resin block 52 comes out of the driven pulley 41. FIG. 8 shows a resin block in a state where it is sandwiched between driven pulleys in a conventional continuously variable transmission.

<Other embodiments>
The continuously variable transmission and the straddle-type vehicle according to the present invention are not limited to the above-described embodiment, and can be changed without departing from the gist of the present invention.

  The straddle-type vehicle according to the present invention is not limited to the motorcycle 1 as described above, but may be other types of straddle-type vehicles. For example, a scooter type straddle-type vehicle may be used. Alternatively, it may be a four-wheel buggy such as ATV (All Terrain Vehicle).

  The V belt only needs to have at least a portion made of a resin in contact with the surface of the driven pulley. Further, the V belt is not necessarily limited to the structure like the V belt 39 of the above embodiment. For example, the resin block 52 may have a shape as described below.

  As shown in FIGS. 9 and 10, the shapes of the first outer side surface 57a and the second outer side surface 57b may be different from those of the above embodiment. In the resin block 52 shown in FIG. 9, the first outer side surface 57a and the second outer side surface 57b are parallel to each other. When the resin block 52 has such a shape, it is easy to measure the dimension between the first outer side surface 57a and the second outer side surface 57b. For this reason, a highly accurate metal mold | die can be created easily. In the resin block 52 shown in FIG. 10, the first outer side surface 57 a and the second outer side surface 57 b are inclined so that the distance from each other becomes narrower toward the upper side.

  In the above embodiment, the entire first outer side surface 57a and second outer side surface 57b of the outer block portion 52a are not in contact with the driven pulley 41, but the driven pulley 41 of the inner block portion 52b. The area of the part in contact with the outer block 52a only needs to be larger than the area of the part in contact with the driven pulley 41 of the outer block 52a. For example, as shown in FIGS. 11 and 12, a gap is provided between a part of the first outer side surface 57a and the first virtual extension surface 58a, and a part of the second outer side surface 57b and the second virtual side surface 57b. A gap may be provided between the extended surface 58b.

  In the resin block 52 shown in FIG. 11, the first outer side surface 57a has a first contact portion 76a and a first non-contact portion 77a. The first non-contact part 77a is located above the first contact part 76a. The first contact portion 76a is inclined at the same angle as that of the first inner side surface 56a, and is provided along the first virtual extension surface 58a. The first non-contact portion 77a is disposed so that a gap is provided between the first non-contact portion 77a and the first virtual extension surface 58a. Accordingly, the first contact portion 76a is in contact with the first surface 46, but the first non-contact portion 77a is not in contact with the first surface 46. The second outer side surface 57b has a second contact portion 76b and a second non-contact portion 77b. The second non-contact part 77b is located above the second contact part 76b. The second contact portion 76b is inclined at the same angle as the second inner side surface 56b, and is provided along the second virtual extension surface 58b. The second non-contact portion 77b is disposed so that a gap is provided between the second non-contact portion 77b and the second virtual extension surface 58b. Therefore, the second contact portion 76 b comes into contact with the second surface 47, but the second non-contact portion 77 b comes into non-contact with the second surface 47.

  In the resin block 52 shown in FIG. 12, the 1st outer side surface 57a has the 1st contact part 78a and the 1st non-contact part 79a. The first contact portion 78a is inclined at the same angle as that of the first inner side surface 56a, and is provided along the first virtual extension surface 58a. Further, as shown in FIG. 12A, the first contact portion 78a is partially provided in the thickness direction of the resin block 52 on the first outer side surface 57a. Specifically, the first contact portion 78a is provided in the central portion in the thickness direction of the resin block 52 on the first outer side surface 57a. The thickness direction of the resin block 52 corresponds to the longitudinal direction of the V belt 39. The first non-contact portion 79a is disposed so as to surround the upper side of the first contact portion 78a and both sides in the thickness direction. The first non-contact portion 79a is disposed so that a gap is provided between the first non-contact portion 79a and the first virtual extension surface 58a. Accordingly, the first contact portion 78a is in contact with the first surface 46, but the first non-contact portion 79a is not in contact with the first surface 46. Further, the second outer side surface 57b has a second contact portion 78b and a second non-contact portion 79b. The second contact portion 78b has the same structure as the first contact portion 78a, and the second non-contact portion 79b has the same structure as the first non-contact portion 79a.

  Further, like the resin block 52 shown in FIG. 13, the length L1 in the vertical direction of the inner block portion 52b may be larger than the length L2 in the vertical direction of the outer block portion 52a. Also in this case, the area of the portion of the inner block 52b that contacts the driven pulley 41 is larger than the area of the portion of the outer block 52a that contacts the driven pulley 41. Here, the “length in the vertical direction” corresponds to the length in the radial direction of the driven pulley 41 at the position where the resin block 52 is wound around the driven pulley 41.

  Further, the shape of the resin block 52 shown in any of FIGS. 5 and 9 to 12 and the shape of the resin block 52 shown in FIG. 13 may be combined. For example, as in the resin block 52 shown in FIG. 14, a gap is provided between at least a part of the first outer side surface 57a and the first virtual extension surface 58a, and at least a part of the second outer side surface 57b and the second A gap is provided between the virtual extension surface 58b. The vertical length of the inner block portion 52b is larger than the vertical length of the outer block portion 52a. In this case, the decrease in the contact area between the outer block 52 a and the driven pulley 41 is compensated by the contact area between the inner block 52 b and the driven pulley 41. For this reason, the contact area with the driven pulley 41 as the resin block 52 as a whole can be maintained at a required size.

  Moreover, like the resin block 52 shown in FIG. 15, the inner block part 52b may be formed of a material having a larger friction coefficient than the outer block part 52a. For example, the inner block portion 52b may be formed of a resin such as nylon, and the outer block portion 52a may be formed of a fluororesin such as PTFE (polytetrafluoroethylene). Also in this case, the frictional force applied from the driven pulley 41 to the inner block portion 52b is larger than the frictional force applied from the driven pulley 41 to the outer block portion 52a.

  Further, like the resin block 52 shown in FIGS. 16 and 17, the connecting member 53 may not be disposed on the side surface of the resin block 52. In the resin block 52, the frictional force applied from the driven pulley 41 to the lower portion of the resin block 52 is greater than the frictional force applied from the driven pulley 41 to the upper portion of the resin block 52. Any shape that is large may be used.

  In FIG. 16, one side surface of the resin block 52 has a first lower side portion 87a and a first upper side portion 88a. The first upper portion 88a is arranged such that a gap is provided between the first upper portion 88a and the first virtual extension surface 89a including the first lower portion 87a. Accordingly, the first lower side portion 87a is in contact with the first surface 46, but the first upper side portion 88a is not in contact with the first surface 46. The other side surface of the resin block 52 includes a second lower side portion 87b and a second upper side portion 88b. The second upper portion 88b is disposed such that a gap is provided between the second upper portion 88b and the second virtual extension surface 89b including the second lower portion 87b. Accordingly, the second lower side portion 87 b is in contact with the second surface 47, but the second upper side portion 88 b is not in contact with the second surface 47.

  In FIG. 17, the lower portion 91 a of the resin block 52 is formed of a material having a larger friction coefficient than the upper portion 91 b of the resin block 52.

  INDUSTRIAL APPLICABILITY The present invention has an effect of suppressing rider discomfort due to stick-slip noise, and is useful as a continuously variable transmission and a saddle type vehicle.

21 Crankshaft (drive shaft)
31 Drive-side pulley 27 Driven shaft 41 Driven-side pulley 52 Resin block 39 V-belt 30 CVT (continuously variable transmission)
53 Connecting member 52a Outer block portion 52b Inner block portion 1 Motorcycle (saddle-ride type vehicle)
46 1st surface 47 2nd surface 56a 1st inner side surface 56b 2nd inner side surface 57a 1st outer side surface 57b 2nd outer side surface 58a 1st virtual extension surface 58b 2nd virtual extension surface

Claims (10)

A drive shaft;
A driving pulley provided on the driving shaft;
A driven shaft disposed away from the drive shaft;
A driven pulley provided on the driven shaft;
A plurality of resin blocks provided at least in contact with the driving pulley and the driven pulley, and an endless connecting member that connects the resin blocks, and the driving pulley and the driven pulley A V-belt wrapped around the side pulley;
With
The frictional force applied from the driven pulley to the portion of the resin block located on the small diameter side of the driven pulley is applied to the portion of the resin block located on the large diameter side of the driven pulley. It is larger than the friction force applied from the driving pulley.
Continuously variable transmission. The resin block includes an outer block portion positioned on a large diameter side of the driven pulley with respect to the connecting member, an inner block portion positioned on a small diameter side of the driven pulley with respect to the connecting member, Have
The friction force applied to the inner block portion from the driven pulley is larger than the friction force applied to the outer block portion from the driven pulley.
The continuously variable transmission according to claim 1. The area of the inner block portion in contact with the driven pulley is larger than the area of the outer block portion in contact with the driven pulley,
The continuously variable transmission according to claim 2. The driven pulley has a first surface and a second surface that are arranged to face each other so as to sandwich the V-belt and are inclined at a predetermined sandwiching angle so that a larger distance is provided toward the larger diameter side. ,
The inner block portion is opposed to the first surface and is inclined corresponding to the inclination of the first surface, and the inner block portion is opposed to the second surface and corresponds to the inclination of the second surface. An inclined second inner side surface;
The outer block portion has a first outer side surface facing the first surface and a second outer side surface facing the second surface;
A gap is provided between the first virtual extension surface including the first inner side surface and at least a part of the first outer side surface, the second virtual extension surface including the second inner side surface, and the first 2 A gap is provided between at least a part of the outer side surfaces,
The continuously variable transmission according to claim 3. A gap is provided between the entire first outer side surface and the first virtual extension surface, and a gap is provided between the entire second outer side surface and the second virtual extension surface.
The continuously variable transmission according to claim 4. A gap is provided between a part of the first outer side surface and the first virtual extension surface, and a gap is provided between a part of the second outer side surface and the second virtual extension surface. Yes,
The continuously variable transmission according to claim 4. The length of the inner block portion in the radial direction of the driven pulley is larger than the length of the outer block portion in the radial direction of the driven pulley.
The continuously variable transmission according to claim 3. The portion of the resin block located on the small diameter side of the driven pulley is formed of a material having a larger friction coefficient than the portion of the resin block located on the large diameter side of the driven pulley. Yes,
The continuously variable transmission according to claim 1. The inner block portion is formed of a material having a larger coefficient of friction than the outer block portion,
The continuously variable transmission according to claim 2.   A straddle-type vehicle comprising the continuously variable transmission according to claim 1.

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