JP2023149418A - Tension adjustment mechanism - Google Patents

Abstract

To provide a tension adjustment mechanism capable of facilitating adjustment of the tension of an endless member.SOLUTION: A tension adjustment mechanism 60 is provided on a motorcycle including: a power unit which is a power source; a swing arm 31 which is provided to be oscillatable vertically to support a rear wheel; a driving sprocket which receives an output of the power unit for rotating; a driven sprocket which is arranged behind the driving sprocket and is coupled to the rear wheel; and a drive chain which is engaged with the driving sprocket and the driven sprocket and transmits the torque of the driving sprocket to the driven sprocket. The tension adjustment mechanism 60 includes: a long hole 61 which is formed at the swing arm 31, into which an axle 3a of the rear wheel is inserted, and which permits forward and backward movement of the axle 3a; and an elastic member 63 which is stretched between the swing arm 31 and the axle 3a, and applies an elastic force to the opposite side to the driving sprocket to the axle 3a.SELECTED DRAWING: Figure 2

Description

The present invention relates to a tension adjustment mechanism.

2. Description of the Related Art Conventionally, some saddle-riding vehicles such as motorcycles are equipped with a mechanism for transmitting the driving force of a power unit to a rear wheel through an endless member such as a drive chain. In this type of vehicle, the chain stretches and becomes slack due to use, so it is common to be provided with a tension adjustment mechanism to adjust the tension of the chain (see, for example, Patent Document 1). Patent Document 1 describes an adjuster for a rear wheel drive chain that includes a main body that is inserted into the rear end of the swing arm and through which the rear axle passes, and a main body that protrudes rearward from the main body and is attached to the rear end of the swing arm. A configuration is disclosed that includes an adjustment bolt that penetrates the cap member and protrudes rearward from the swing arm, and an adjustment nut that is screwed onto the adjustment bolt and is seated on the rear end surface of the cap member. With this adjuster, the tension of the chain can be adjusted by turning the adjustment nut and moving the adjustment bolt back and forth to finely adjust the front and back position of the rear axle along with the adjuster body.

Japanese Patent Application Publication No. 2007-1472

However, with the tension adjustment mechanism of the prior art, the front and back position of the rear axle must be manually adjusted by the operator, and there is room for improvement in the workability of setting the endless member to a desired tension.

Therefore, the present invention provides a tension adjustment mechanism that can easily adjust the tension of an endless member.

The tension adjustment mechanism according to the first aspect of the present invention includes a power unit (40) that is a power source, a swing arm (31) that is vertically swingable and supports a rear wheel (3), and a swing arm (31) that is vertically swingable and supports a rear wheel (3). ), a driven member (52) arranged behind the driving member (51) and coupled to the rear wheel (3), and the driving member (51) and an endless member (53) that is wrapped around the driven member (52) and transmits the torque of the drive member (51) to the driven member (52), A long hole (61) formed in the swing arm (31), into which the axle (3a) of the rear wheel (3) is inserted, and which allows the axle (3a) to move back and forth; ) and an elastic member (63) that is bridged between the axle (3a) and applies an elastic force to the axle (3a) on a side opposite to the drive member (51).

A tension adjustment mechanism according to a second aspect of the present invention is the tension adjustment mechanism according to the first aspect, further comprising a collar member (71) fitted onto the axle (3a), and wherein the elastic member (63) is , elastic force may be indirectly applied to the axle (3a) via the collar member (71).

In the tension adjustment mechanism according to a third aspect of the present invention, in the tension adjustment mechanism according to the second aspect, the swing arm (31) is formed in a hollow shape having an opening (34) at the rear end, and the elastic member (63) and the collar member (71) are arranged inside the swing arm (31), close the opening (34), and are connected to the swing arm (31) via the elastic member (63). It may further include a cap member (80).

In the tension adjustment mechanism according to the fourth aspect of the present invention, in the tension adjustment mechanism according to the third aspect, the cap member (80) is inserted and the collar member (71) is rotated relative to the cap member (80). ) may further include a set bolt (67) that presses the drive member (51).

The tension adjustment mechanism according to a fifth aspect of the present invention is the tension adjustment mechanism according to any one of the first to fourth aspects, in which the elastic member (63) acts on the axle (3a). The elastic force may change so as to converge to a predetermined value as the axle (3a) moves away from the drive member (51).

A tension adjustment mechanism according to a sixth aspect of the present invention is the tension adjustment mechanism according to any one of the first to fifth aspects, wherein the swing arm (31) is configured to sandwich the rear wheel (3). It has a pair of left and right support parts (34a) arranged on both sides in the vehicle width direction, the elongated hole (61) is formed in each of the pair of support parts (34a), and the elastic member (63) , may be bridged between each of the pair of support parts (34a) and the axle (3a).

According to the tension adjustment mechanism of the first aspect, by making the axle of the rear wheel movable back and forth within the elongated hole, the axle is separated from the driving member together with the driven member by the elastic force applied from the elastic member. can be displaced in the direction. Thereby, when eliminating slack in the endless member, it is possible to omit the step of retracting the axle and the driven member by an operator's operation. Therefore, the tension of the endless member can be easily adjusted by the elastic force of the elastic member.

According to the tension adjustment mechanism of the second aspect, when the tension adjustment mechanism is incorporated into a saddle-ride type vehicle, the elastic force of the elastic member is applied to the axle by inserting the axle through the collar member. Compared to a configuration in which the tension adjustment mechanism is connected to the axle and applies elastic force directly to the axle, the ease of assembling the tension adjustment mechanism can be improved.

According to the tension adjustment mechanism of the third aspect, the tension adjustment mechanism can be assembled into a saddle-ride type vehicle by inserting the elastic member and the collar member through the opening of the swing arm and attaching the cap member. Therefore, the ease of assembling the tension adjustment mechanism can be further improved.

According to the tension adjustment mechanism of the fourth aspect, by rotating the set bolt with respect to the cap member, the collar member can be displaced toward the driving member together with the axle and the driven member. Therefore, the axle and the driven member can be moved forward without removing the cap member.

According to the tension adjustment mechanism of the fifth aspect, it is possible to suppress variations in the tension of the endless member depending on the positions of the axle and the driven member in the longitudinal direction. Therefore, the tension of the endless member can be stabilized.

According to the tension adjustment mechanism of the sixth aspect, the axle can be equally displaced in the direction away from the drive member on both sides of the rear wheel in the vehicle width direction. Therefore, tilting of the axle due to adjustment of the tension of the endless member can be suppressed.

FIG. 1 is a left side view of the motorcycle according to the first embodiment. 2 is a sectional view taken along line II-II in FIG. 1. FIG. 3 is a cross-sectional view of a portion corresponding to line III-III in FIG. 2. FIG. It is a figure which shows the state before incorporating a tension adjustment mechanism into a swing arm. It is a figure showing the state where a set bolt presses an adjuster. 3 is a diagram showing a tension adjustment mechanism according to a second embodiment, and is a partial cross-sectional view corresponding to FIG. 2. FIG. 6 is a diagram showing a tension adjustment mechanism according to a second embodiment, and a cross-sectional view corresponding to FIG. 5. FIG.

Embodiments of the present invention will be described below based on the drawings. In the following description, components having the same or similar functions are given the same reference numerals. Further, redundant explanations of these configurations may be omitted. In addition, directions such as front, rear, top, bottom, left, and right in the following description are the same as directions in the vehicle described below. That is, the up-down direction coincides with the vertical direction, and the left-right direction coincides with the vehicle width direction. Further, in the figures used in the following explanation, arrow UP indicates upward, arrow FR indicates forward, and arrow LH indicates left.

FIG. 1 is a left side view of the motorcycle according to the first embodiment.
As shown in FIG. 1, a motorcycle 1 is an example of a vehicle to which the power transmission structure of the present invention is applied. The motorcycle 1 includes a front wheel 2, a rear wheel 3, a body frame 10, a rear suspension 30 that is supported by the body frame 10 so as to be able to swing vertically, a power unit 40 that is a power source, and a rear suspension 30 that is a power source. It includes a power transmission device 50 that transmits to the wheel 3 and a tension adjustment mechanism.

The vehicle body frame 10 includes a head pipe 11, a pair of left and right main frames 12, a pair of left and right pivot frames 13, a down frame 14, a lower frame 15, and a subframe 16, which are welded, fastened, etc. are joined together. The head pipe 11 is provided at the front end of the vehicle body frame 10. The head pipe 11 supports the front wheel 2 via a steering mechanism so that the front wheel 2 can be steered. The pair of main frames 12 are branched left and right from the top of the head pipe 11 and extend rearward and downward. The pair of pivot frames 13 each extend downward from the rear end of the main frame 12. The down frame 14 extends downward from the bottom of the head pipe 11. The lower frame 15 extends rearward from the lower end of the down frame 14 and is connected to the lower end of the pivot frame 13, respectively. The pair of pivot frames are connected to a pivot extending in the vehicle width direction, and swingably support a swing arm 31, which will be described later, via the pivot. The subframe 16 includes a pair of seat rails 17 and a support pipe 18. A pair of seat rails 17 are provided on the left and right sides. A pair of seat rails 17 extend rearward from the main frame 12. The support pipe 18 extends upward and rearward from the pivot frame 13 and is coupled to the front and rear intermediate portions of the left and right seat rails 17.

The rear suspension 30 includes a swing arm 31 supported by the pivot frame 13 so as to be able to swing up and down, and a rear cushion 32 that applies a swing reaction force to the swing arm 31. The swing arm 31 is provided below the rear of the vehicle body. The swing arm 31 is formed into a hollow shape having an opening 34 at the rear end. The swing arm 31 includes a base portion 33 supported by a pivot, and a pair of left and right arm bodies 34a (support portions) extending rearward from the base portion 33. The arm main bodies 34a are arranged on both sides of the vehicle widthwise with the rear wheel 3 in between. The arm body 34a supports the axle 3a of the rear wheel 3. An opening 34 is formed at the rear end of the arm body 34a. The rear cushion 32 is arranged below the rear part of the vehicle body. The rear cushion 32 is formed in a cylindrical shape and extends vertically along a forwardly inclined axial direction (longitudinal direction). The upper end of the rear cushion 32 is rotatably connected to the upper part of the pivot frame 13. A lower end portion of the rear cushion 32 is connected to the swing arm 31 via a link mechanism.

The power unit 40 is fixedly supported by the vehicle body frame 10. The power unit 40 is arranged in an area surrounded by the main frame 12, the pivot frame 13, and the down frame 14 when viewed from the side. Power unit 40 includes an engine 41 that is a prime mover. The power unit 40 includes a clutch device, a transmission, and an output shaft that are provided integrally with the engine 41. Power unit 40 outputs the rotational driving force of the crankshaft of engine 41 to the outside via a clutch device and a transmission. The output shaft extends in the vehicle width direction and protrudes to the left from the housing (crankcase) of the power unit 40.

The power transmission device 50 is a chain drive type power transmission mechanism. The power transmission device 50 includes a driving sprocket 51 (driving member) that rotates in response to the output of the power unit 40, a driven sprocket 52 (driven member) coupled to the rear wheel 3, and a sprocket that is wound around the driving sprocket 51 and the driven sprocket 52. drive chain 53 (endless member). The drive sprocket 51 is coupled to the output shaft of the power unit 40. The center axis of the driven sprocket 52 is located behind the center axis of the driving sprocket 51 in side view. The center axis of the driven sprocket 52 may be vertically offset from the center axis of the drive sprocket 51, but in this embodiment, for convenience, it is arranged at the same height as the center axis of the drive sprocket 51. do. The drive sprocket 51 transmits the output of the power unit 40 to the drive chain 53 to rotate the drive chain 53. The drive chain 53 transmits the torque of the driving sprocket 51 to the driven sprocket 52. The driven sprocket 52 transmits the rotation of the drive chain 53 to the rear wheel 3.

FIG. 2 is a cross-sectional view taken along line II-II in FIG. FIG. 3 is a cross-sectional view of a portion corresponding to line III--III in FIG.
As shown in FIGS. 2 and 3, the tension adjustment mechanism 60 is provided for each arm body 34a of the swing arm 31. As shown in FIGS. In this embodiment, the tension adjustment mechanism 60 provided on the left arm main body 34a and the tension adjustment mechanism 60 (not shown) provided on the right arm main body 34a are configured symmetrically with respect to each other. In the following description, the tension adjustment mechanism 60 provided on the left arm main body 34a will be described. The tension adjustment mechanism 60 is formed in the arm body 34a, and includes a long hole 61 through which the axle 3a of the rear wheel 3 is inserted, an elastic member 63 spanned between the arm body 34a and the axle 3a, and an elastic member 63 between the axle 3a and the elastic member. It includes an adjuster 70 that connects the members 63, a cap member 80 that closes the rear end opening 34 of the arm body 34a, and a cap bolt 65 that is attached to the cap member 80.

The long holes 61 are formed in both the inner and outer walls in the vehicle width direction in each arm main body 34a. The elongated hole 61 is formed to be elongated in the vehicle longitudinal direction. The long hole 61 allows the axle 3a of the rear wheel 3 to move back and forth. The axle 3a of the rear wheel 3 is a long bolt having a hexagonal head at one end (the left end in the illustrated example), and an axle nut (not shown) is screwed onto the other end, thereby forming a pair of arm bodies 34a. It has been concluded. The axle 3a is fastened to the arm body 34a via a washer 36 that prevents rotation. Since the washer 36 has a sufficiently long diameter in the short side direction of the elongated hole 61, the collar member 71 can be sufficiently fixed to the arm body 34a. A wheel side collar 4 is extrapolated onto the axle 3a. The wheel side collar 4 is interposed between the wall portion of the arm body 34a on the opposite side in the vehicle width direction and the wheel of the rear wheel 3, and adjusts the distance between the arm body 34a and the wheel of the rear wheel 3.

The adjuster 70 is arranged inside the arm main body 34a. Adjuster 70 is made of metal material. The adjuster 70 includes a cylindrical collar member 71 and a plate 72 coupled to the collar member 71. The collar member 71 and the plate 72 are fixedly connected to each other by welding or the like. The collar member 71 extends along the vehicle width direction and is fitted onto the axle 3a. The plate 72 includes a pair of left and right side plate portions 73 spaced apart from each other in the vehicle width direction, and a rear plate portion 74 that connects the rear ends of the side plate portions 73 to each other. The pair of side plate portions 73 hold the collar member 71 from both sides in the vehicle width direction. Each side plate portion 73 is formed with a through hole 73a that communicates with the inside of the collar member 71 and into which the axle 3a is inserted. The side plate portion 73 is in sliding contact with the inner surface of the arm body 34a, and maintains the posture of the adjuster 70 by restricting rotation of the adjuster 70 around the axle 3a. The side plate portion 73 is formed to be larger than the elongated hole 61 in side view, and prevents the adjuster 70 from falling off from inside the arm body 34a through the elongated hole 61 by interfering with the opening edge of the elongated hole 61. are doing. The rear plate portion 74 is disposed on the rear end opening 34 side (that is, rearward) of the arm body 34a with respect to the collar member 71. The rear plate portion 74 holds the screw receiving portion 75 by welding or the like. In the illustrated example, the screw receiving portion 75 is formed into a nut shape. The inner circumferential surface of the screw receiving portion 75 is formed to be smooth and cannot be engaged with a set bolt 67, which will be described later. The screw receiving portion 75 is arranged coaxially with a virtual axis P that extends in the front-rear direction and intersects the central axis of the axle 3a. A through hole 74a communicating with the opening of the screw receiving part 75 is formed in the rear plate part 74.

The cap member 80 is made of a metal material. The cap member 80 is detachably attached to and non-rotatably fixed to the arm body 34a. For example, the cap member 80 is attached to the arm body 34a by fastening or the like. However, the cap member 80 may be held on the arm body 34a by the urging force of the elastic member 63. The cap member 80 holds a nut 81, into which the cap bolt 65 is screwed, inside the arm body 34a by welding or the like. The nut 81 may be integrally molded with the cap member 80. The nut 81 is arranged coaxially with the screw receiving part 75 held by the adjuster 70. The cap member 80 is formed with a through hole that communicates with the opening of the nut 81 and into which the cap bolt 65 is inserted.

The elastic member 63 is arranged inside the arm body. The elastic member 63 is a tension coil spring. The elastic members 63 are arranged on both sides above and below the central axis of the axle 3a when viewed from the side. One end (front end) of each elastic member 63 is connected to an adjuster 70. The other end (rear end) of each elastic member 63 is connected to a cap member 80. Thereby, the elastic member 63 indirectly applies an elastic force to the axle 3a on the side opposite to the drive sprocket 51 (rearward) via the adjuster 70. The elastic force acting on the axle 3a by the elastic member 63 changes so as to converge to a predetermined value as the axle 3a moves away from the drive sprocket 51. In this embodiment, the elastic member 63 is a nonlinear spring, and is formed so that its spring constant increases as its length approaches its natural length as it contracts.

The cap bolt 65 is inserted into the through hole 82 of the cap member 80 from the rear. The cap bolt 65 is screwed into a nut 81 held by the cap member 80. The head of the cap bolt 65 closes the through hole 82 of the cap member 80.

The tension adjustment mechanism 60 is formed so that a set bolt 67 can be attached instead of the cap bolt 65. The set bolt 67 is rotated relative to the cap member 80 to press the adjuster 70 toward the drive sprocket 51 side. The set bolt 67 is inserted through the through hole 82 of the cap member 80 and the nut 81. The set bolt 67 is screwed into the nut 81. The set bolt 67 is inserted through the through hole 74a of the rear plate portion 74 of the adjuster 70 and the screw receiving portion 75. The tip of the set bolt 67 is abutted against the outer peripheral surface of the collar member 71 of the adjuster 70.

The operation of the tension adjustment mechanism 60 of this embodiment will be explained.
FIG. 4 is a diagram showing a state before the tension adjustment mechanism is assembled into the swing arm.
As shown in FIG. 4, when the tension adjustment mechanism 60 is assembled into the swing arm 31, the swing arm 31 is in a state in which the axle 3a is removed. With the adjuster 70 and the cap member 80 connected by the elastic member 63, the adjuster 70 is inserted from the rear end opening 34 of the arm main body 34a. At this time, it is desirable from the viewpoint of work efficiency to maintain the distance between the adjuster 70 and the cap member 80 while resisting the restoring force of the elastic member 63. Therefore, instead of the cap bolt 65, a set bolt 67 is screwed into the nut 81 held by the cap member 80, and while the set bolt 67 restricts the approach of the adjuster 70 to the cap member 80 side, the adjuster 70 is inserted from the rear end opening 34 of the arm main body 34a. Note that the set bolt 67 may be assembled to the adjuster 70 and the cap member 80 after the adjuster 70 is inserted into the arm main body 34a. Preferably, by adjusting the position of the collar member 71 of the adjuster 70 with respect to the cap member 80 in advance, the axle 3a inserted through the collar member 71 can be positioned. For example, the position of the adjuster 70 with respect to the cap member 80 is set so that the collar member 71 is located at a position corresponding to the front end of the elongated hole 61. The cap member 80 is fixed to the arm body 34a, and the axle 3a is inserted into the elongated hole 61 and the inside of the collar member 71. The tension adjustment mechanism 60 is incorporated into the swing arm 31 by fastening the axle 3a to the arm body 34a. Note that it is desirable that the set bolt 67 be removed and replaced with the cap bolt 65 when the vehicle is running.

When the drive chain 53 becomes slack due to elongation or the like, the axle 3a is disengaged from the arm body 34a of the swing arm 31. This allows the axle 3a to move back and forth within the elongated hole 61 of the arm body 34a. Since the axle shaft 3a is given an elastic force by the elastic member 63 in a direction away from the drive sprocket 51, it is displaced rearward together with the driven sprocket 52 and the rear wheel 3 with respect to the arm body 34a. This eliminates slack in the drive chain 53. Then, by re-fastening the axle 3a to the arm body 34a, adjustment of the tension of the drive chain 53 is completed.

FIG. 5 is a diagram showing a state in which the set bolt presses the adjuster.
When replacing the elongated drive chain 53 with a new drive chain 53 with less elongation, the axle 3a is disengaged from the arm body 34a, and the driven sprocket 52 is displaced toward the drive sprocket 51. In this case, as shown in FIG. 5, instead of the cap bolt 65, a set bolt 67 is inserted into the through hole 82 of the cap member 80 from the rear. The set bolt 67 is inserted through the through hole 82 and nut 81 of the cap member 80, and through the through hole 74a of the rear plate portion 74 of the adjuster 70 and the screw receiving portion 75. In this state, the set bolt 67 is screwed into the nut 81, so its displacement with respect to the cap member 80 is restricted, and it is freely rotatable with respect to the adjuster 70. When the set bolt 67 is rotated in the tightening direction with respect to the cap member 80, the set bolt 67 rotates and moves forward with respect to the cap member 80 and the arm body 34a. When the set bolt 67 moves forward, the adjuster 70 in contact with the tip of the set bolt 67 moves forward together with the axle 3a. Thereby, the driven sprocket 52 can be displaced toward the driving sprocket 51 side. By re-fastening the axle 3a to the arm body 34a with the axle 3a disposed at a predetermined position (for example, at the front end of the elongated hole 61), the position adjustment required to move the driven sprocket 52 forward is completed.

As described above, the tension adjustment mechanism 60 of the present embodiment includes an elastic member that is bridged between the swing arm 31 and the axle 3a, and that applies an elastic force to the axle 3a on the side opposite to the drive sprocket 51. 63. According to this configuration, by loosening the fastening of the axle 3a so that the axle 3a can move back and forth within the elongated hole 61, the elastic force applied from the elastic member 63 moves the axle 3a together with the driven sprocket 52 to drive the drive sprocket. It can be displaced in the direction away from 51. Thereby, when eliminating slack in the drive chain 53, the step of retracting the axle 3a and the driven sprocket 52 by the operator's operation can be omitted. Therefore, the tension of the drive chain 53 can be easily adjusted by the elastic force of the elastic member 63.

Moreover, the tension adjustment mechanism 60 further includes a collar member 71 that is fitted onto the axle 3a. The elastic member 63 indirectly applies elastic force to the axle 3a via the collar member 71. According to this configuration, when the tension adjustment mechanism 60 is assembled into the motorcycle 1, the elastic force of the elastic member 63 is applied to the axle 3a by inserting the axle 3a through the collar member 71, so that the elastic member is connected to the axle. Compared to a configuration in which elastic force is directly applied to the axle by applying elastic force to the axle, ease of assembling the tension adjustment mechanism 60 can be improved.

The elastic member 63 and the collar member 71 are arranged inside the arm body 34a of the swing arm 31. The tension adjustment mechanism 60 further includes a cap member 80 that closes the rear end opening 34 of the arm body 34a and connects the arm body 34a and the elastic member 63. According to this configuration, the tension adjustment mechanism 60 can be assembled to the motorcycle 1 by inserting the elastic member 63 and the collar member 71 from the rear end opening 34 of the arm main body 34a and attaching the cap member 80. Therefore, the ease of assembling the tension adjustment mechanism 60 can be further improved.

The tension adjustment mechanism 60 further includes a set bolt 67 that is inserted through the cap member 80 and presses the collar member 71 toward the driving sprocket 51 as it rotates with respect to the cap member 80 . According to this configuration, by rotating the set bolt 67 with respect to the cap member 80, the collar member 71 can be displaced toward the driving sprocket 51 together with the axle 3a and the driven sprocket 52. Therefore, the axle 3a and the driven sprocket 52 can be moved forward without removing the cap member 80.

The elastic force acting on the axle 3a by the elastic member 63 changes so as to converge to a predetermined value as the axle 3a moves away from the drive sprocket 51. According to this configuration, it is possible to suppress variations in the tension of the drive chain 53 depending on the positions of the axle 3a and the driven sprocket 52 in the longitudinal direction. Therefore, the tension of the drive chain 53 can be stabilized.

The tension adjustment mechanism 60 is provided on each of the left and right arm bodies 34a. According to this configuration, the axle 3a can be equally displaced in the direction away from the drive sprocket 51 on both sides of the rear wheel 3 in the vehicle width direction. Therefore, tilting of the axle 3a due to adjustment of the tension of the drive chain 53 can be suppressed.

Note that the configuration of the adjuster is not limited to the above embodiment. For example, in the above embodiment, the adjuster 70 is provided with the nut-shaped screw receiving portion 75, but the screw receiving portion 75 may be omitted. However, since the set bolt 67 can be smoothly guided in the front-rear direction, it is desirable to provide the screw receiving part 75.

Further, in the above embodiment, the inner circumferential surface of the screw receiving portion 75 is formed to be smooth, but a female thread having a smaller diameter than the set bolt 67 is formed, for example, so that the set bolt 67 cannot be inserted. Good too. In this case, the tip of the set bolt 67 contacts the rear opening edge of the screw receiving portion 75 instead of the outer peripheral surface of the collar member 71 of the adjuster 70 .

Further, as shown in FIGS. 6 and 7, a cylindrical member 76 that holds the shaft portion of the set bolt 67A may be coupled to the collar member 71A. The cylindrical member 76 rotatably holds the set bolt 67A. The tip of the set bolt 67A comes into contact with the inner stepped surface of the cylindrical member 76. However, the tip of the set bolt 67A may come into contact with the inner bottom surface of the cylindrical member 76 (the outer peripheral surface of the collar member 71A). Even with such a configuration, the adjuster 70A can be pressed toward the drive sprocket 51 by rotating the set bolt 67A relative to the cap member 80 and moving it forward. By holding the set bolt 67A in the cylindrical member 76, the posture of the collar member 71A can be maintained. Note that the elastic member 63 may be directly connected to the collar member 71A as illustrated.

Further, the present invention can be applied to all saddle type vehicles in which a driver rides while straddling the vehicle body. In other words, the present invention is applicable not only to motorcycles but also to tricycles. Further, the present invention can be applied to a vehicle equipped with a motor as a prime mover.

Further, the present invention is not limited to the above-described embodiments described with reference to the drawings, and various modifications can be made within the technical scope thereof.
For example, in the above embodiment, the present invention is applied to the motorcycle 1 having a chain drive type power transmission device 50, but the present invention may be applied to a motorcycle having a belt drive type power transmission device. . That is, the tension adjustment mechanism of the present invention may be configured as an endless member to adjust the tension of the drive belt.

Further, in the above embodiment, the elastic member 63, which is a non-linear spring, is used to suppress the elastic force acting on the axle 3a from changing depending on the position of the axle 3a in the longitudinal direction. Not limited. For example, the elastic force acting on the axle 3a may be adjusted by combining a plurality of springs.

In addition, the components in the embodiments described above may be replaced with known components as appropriate without departing from the spirit of the present invention, and the embodiments described above may be combined as appropriate.

1... Motorcycle (saddle type vehicle) 3... Rear wheel 3a... Axle 31... Swing arm 34... Opening 34a... Arm body (support part) 40... Power unit 51... Drive sprocket (drive member) 52... Driven sprocket (driven member) ) 53... Drive chain (endless member) 60... Tension adjustment mechanism 61... Long hole 63... Elastic member 67, 67A... Set bolt 71, 71A... Collar member 80... Cap member

Claims (6)

A power unit (40) that is a power source,
a swing arm (31) that is vertically swingable and supports the rear wheel (3);
a drive member (51) that rotates in response to the output of the power unit (40);
a driven member (52) disposed behind the drive member (51) and coupled to the rear wheel (3);
an endless member (53) that is wound around the driving member (51) and the driven member (52) and transmits the torque of the driving member (51) to the driven member (52);
provided on a saddle-ride type vehicle (1) having a
an elongated hole (61) formed in the swing arm (31), into which the axle (3a) of the rear wheel (3) is inserted, and which allows the axle (3a) to move back and forth;
an elastic member (63) that spans between the swing arm (31) and the axle (3a) and applies an elastic force to the axle (3a) on a side opposite to the drive member (51);
Tension adjustment mechanism equipped with. Further comprising a collar member (71, 71A) fitted onto the axle (3a),
The elastic member (63) indirectly applies elastic force to the axle (3a) via the collar member (71, 71A).
The tension adjustment mechanism according to claim 1. The swing arm (31) is formed in a hollow shape having an opening (34) at the rear end,
The elastic member (63) and the collar member (71, 71A) are arranged inside the swing arm (31),
The tension adjustment mechanism according to claim 2, further comprising a cap member (80) that closes the opening (34) and is connected to the swing arm (31) via the elastic member (63). It further includes a set bolt (67, 67A) that is inserted through the cap member (80) and presses the collar member (71, 71A) toward the drive member (51) as it rotates with respect to the cap member (80). The tension adjustment mechanism according to claim 3. The elastic force acting on the axle (3a) by the elastic member (63) changes so as to converge to a predetermined value as the axle (3a) moves away from the drive member (51).
The tension adjustment mechanism according to any one of claims 1 to 4. The swing arm (31) has a pair of left and right support portions (34a) disposed on both sides in the vehicle width direction with the rear wheel (3) in between,
The long hole (61) is formed in each of the pair of support parts (34a),
The elastic member (63) is spanned between each of the pair of support parts (34a) and the axle (3a),
The tension adjustment mechanism according to any one of claims 1 to 5.

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