JPH07187051A - Chain extension device for motorcycle - Google Patents

Abstract

PURPOSE:To provide an motorcycle axle support structure capable of improving workability at the time of mounting and demounting a wheel and shortening a work time for a tire change or the like. CONSTITUTION:This chain extension device has a pair of right and left adjusting fittings 10a and 10b jointed to the rear end of each swing arm in such state as freely movable in a longitudinal direction for supporting a rear wheel and holding both ends of an axle 2, and an adjusting bolt for adjusting the longitudinal positions of the fittings 10a and 10b on each swing arm. In this device, the tension of a drive chain 5 is adjusted through the adjustment of the bolt. Also, a constraint means is fitted to the mounting positions 7 and 27 of the fittings 10a and 10b on the swing arm for constraining the motion thereof along the direction of an axle.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a chain pulling device for adjusting and holding an axle of a rear wheel of a motorcycle such that the axle can be moved back and forth.

[0002]

2. Description of the Related Art In a chain drive type motorcycle, as shown in FIG. 3 (a), an axle 2 for rotatably supporting a rear wheel 1 is formed at the rear ends of the left and right swing arms 3a, 3b. The chain pulling devices 6a and 6b are inserted into the long holes 4a and 4b which are long in the front-rear direction and held by the chain pulling devices 6a and 6b so that the front-rear direction can be set. Adjust the distance between the sprockets and adjust the extension of the drive chain 5 due to use.

That is, each of the swing arms 3a, 3a
Chain pulling devices 6a and 6b are attached to the rear end of the wheel b to adjust the position of the axle 2 in the front-rear direction as described above.

The chain pulling device 6 (6a, 6b)
As shown in FIG. 4, a U-shaped adjustment fitting 10 (10a, 10b) in plan view having an axle holding hole 8 at the left and right free ends 7 and a screw hole 9 for an adjusting bolt at the base end is provided. , An adjusting bolt 11 for moving the adjusting metal fitting 10 back and forth with respect to each of the swing arms 3 (3a, 3b).
The elongated holes 4 of the swing arm 3 are mounted so as to be sandwiched from the left and right sides by the free ends 7 on both sides of the V-shaped adjustment fitting 10, and the elongated holes 4 and the axle holding holes 8 are overlapped with each other. , 8, the axle 2 (see FIG. 3 (a)) is inserted, and then the adjusting bolt 11 is rotated to move the adjusting metal fitting 10 back and forth with respect to the swing arm 3 to drive the drive chain 5 (see FIG. Adjust the tension in a). And
As shown in FIG. 3A, after the tension adjustment of the drive chain 5 is completed, the lock nut 12 screwed to the adjustment bolt 11 is tightened to move the adjustment bolt 11 to the adjustment fitting 10.
Lock against. As a related technology of this kind,
There is one disclosed in Japanese Patent No. 1519.

[0005]

However, it is necessary to change tires in a short time especially at a racetrack. In that case, for the purpose of tire replacement, etc., the swinging arms 3a, 3
If the axle 2 is pulled out from b, the adjustment fitting 10
There is nothing to support the swinging arms 3a, 3b on the side, so that when the axle 2 is next inserted, the axle holding hole 8
And the slot 4 must be aligned. At this time, FIG.
As shown in (b), when the axle holding hole 8 of the adjustment fitting 10a on the axle insertion side is misaligned with respect to the axle 2, the screw portion 2a at the tip of the axle 2 has a free end portion of the adjustment fitting 10a on the side opposite to the vehicle body. 7
3 may interfere with the edge of the axle holding hole 8 of FIG. 3, and in such a case, a stress that presses the adjustment fitting 10a in the direction opposite to the vehicle body (A direction in the figure) acts, and when the axle 2 is pulled out, As shown in (c), the screw portion 2a at the tip of the axle has the axle holding hole 8
A stress is applied to the adjustment metal fitting 10b in the direction opposite to the vehicle body (direction B in the figure).

Therefore, in the conventional structure, it is necessary to increase the rigidity of the adjusting metal fitting 10 in consideration of the above-mentioned stress, and in this case, the weight becomes heavy, especially at the race track. It is against the weight reduction to reduce unnecessary weight.

Further, as described in the embodiment, as shown in FIG. 1, in the case of the structure in which the axle fixing nut 19 is fixedly installed in the axle holding hole 8 of the free end portion 7 of the adjustment metal fitting 10a on the side opposite to the vehicle body, Alternatively, when the axle stopper 21 is provided in the axle holding hole 8 of the free end portion 7 on the side opposite to the vehicle body of the adjustment metal fitting 10b on the axle extraction side, these adjustment metal fittings 10a, 1
Since the above-mentioned phenomenon occurs at the free end portion 0b of 0b, the weight of the adjustment fitting may be further increased.

The present invention has been made in view of the above circumstances, and the chain pulling device for a motorcycle, in which the adjustment metal fitting does not deviate in the vertical direction even after the removal of the axle, and the weight of the adjustment metal fitting can be reduced. The purpose is to provide.

[0009]

SUMMARY OF THE INVENTION A chain drawing device for a motorcycle according to the present invention comprises a pair of left and right wheels which are attached to the rear ends of the respective swing arms for supporting the rear wheels so as to be movable back and forth. A chain pulling device for a motorcycle, comprising: an adjusting bracket and an adjusting bolt for adjusting a position of the adjusting bracket in a front-rear direction on a swing arm, and adjusting the tension of a drive chain by rotating the adjusting bolt. And a restraint means for restraining the movement of the adjustment fitting in the axle direction is provided at the mounting position of the swing arm.

In the above invention, the restraint means is provided on one of the adjustment fitting and the swing arm with an engaging portion extending in a direction orthogonal to the axle along the longitudinal direction of the swing arm, and on the other one. It can be formed by providing a dovetail-shaped guide groove for restraining the engaging portion in the axle direction.

Further, in the above invention, when the restraint means is constituted by providing a tubular portion surrounding a swing arm in a direction orthogonal to the longitudinal direction in a part of the adjusting fitting, the restraining means acts on the adjusting fitting. Since the stress in each direction can be transmitted to the swing arm having high rigidity, the rigidity of the adjustment fitting can be further reduced and the weight can be reduced.

[0012]

By configuring the motorcycle chain-drawing device according to the present invention as described above, the stress in the axial direction acting on the adjustment fitting is passed through the restraint means provided at the attachment location of the adjustment fitting and the swing arm. Is transmitted to the swing arm side, the swing arm having high rigidity effectively acts as a reinforcing member against the stress in the axle direction. That is, since it is not necessary to support the stress in the axial direction by the free end portion of the adjustment fitting itself, the thickness of the free end portion of the adjustment fitting can be reduced, and as a result, the weight of the adjustment fitting can be reduced.

Further, since the adjusting metal fitting loses one degree of freedom (vertical degree of freedom) due to the restraint means, it suffices to consider only the front and rear direction of the swing arm with respect to the misalignment, and the adjustment bolt is used to some extent in the front and rear direction. Since it is regulated, consideration for misalignment when inserting the axle is reduced.

[0014]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, a chain pulling device according to an embodiment of the present invention will be described with reference to the drawings.

FIG. 1 is a vertical sectional view taken along the line AA of FIG. 2 showing the structure of the rear wheel support portion of the motorcycle, and FIG. 2 is taken along the line BB of FIG. 1 showing the same structure as that of FIG. FIG. Members common to those in FIGS. 3 and 4 showing the conventional example will be described below by using common reference numerals.

As shown in FIGS. 1 and 2, the rear wheel 1 is rotatably supported by a hollow axle 2.
As shown in FIG. 2, each swing arm 3a,
The elongated holes 4a and 4b formed at the rear end portion of 3b are movably inserted back and forth.

As shown in FIG. 2, the chain pulling devices 6a and 6b for adjusting the longitudinal position of the axle 2 to adjust the extension of the drive chain 5 are provided at the rear ends of the respective swinging arms 3a and 3b. Is attached to. The chain pulling devices 6a, 6b are provided with a U-shaped adjustment fitting 10 in plan view.
a and 10b, and a flanged adjustment bolt 11 having a hexagonal hole at the tip. And the adjusting bolt 11
Is a screw hole 3 penetrating through the base ends of the adjustment fittings 10a and 10b and narrowed at the rear ends of the respective swing arms 3a and 3b.
It is configured to be screwed to A and to rotate the adjustment bolt 11 so that the position of the adjustment fitting 10 (10a, 10b) in the front-rear direction can be set with respect to the swing arms 3a, 3b.

As shown in FIG. 1 or 2, a rear wheel hub 13 is rotatably supported on the axle 2 via bearings 12, 12. Then, a sprocket 14 is mounted adjacent to the left side of the hub 13, and the drive chain 5 wound between the sprocket 14 and a sprocket on the engine side (not shown) causes power to be transmitted to the hub 13 via the coupling portion 15. Be transmitted to. A brake disc 16 is integrally mounted on the right side of the hub 13, and the brake disc 16 is sandwiched between pads of a brake caliper (not shown) to apply braking to the rotation of the rear wheel 1.

Further, as shown in FIG. 2, in the present embodiment, the axle 2 is screwed into the axle holding hole 8 provided at the free end portion 7 of the adjusting metal fitting 10a on the side opposite to the vehicle body. After the nut 19 is fixed by the stopper pin 20 and the tension adjustment of the drive chain 5 is completed, the screw portion 2a at the tip of the axle 2 is screwed onto the nut 19 with a predetermined torque to make the axle 2
Is fixed to the swing arms 3a and 3b through the adjusting metal fittings 10 (10a and 10b).

Further, an axle stopper 21 is attached to the free end portion 7 of the adjusting metal fitting 10b on the side opposite to the vehicle body for the purpose of speeding up the work of attaching and detaching the wheels at the time of tire replacement and the like, and the axle 2 Near the tip of the stopper 21
The locking groove 22 is formed in correspondence with. With this configuration, the locking groove 22 formed on the axle 2 is provided with the stopper 2
The pulling-out of the axle 2 is regulated at the position where it engages with the first locking member 23.

By the way, as shown in FIG. 1, the chain pulling device for a motorcycle according to the present embodiment has a dovetail-shaped guide groove 26 at a mounting position of the adjusting fittings 10a, 10b and the swing arms 3a, 3b. "Restricting means" constituted by the engaging portion 25 fitted in the guide groove 26
Is provided. That is, the adjustment fittings 10a, 10
At the free end portion 7 on the side opposite to the vehicle body of b, an engaging portion 25 having a widened width (upper and lower dimensions in FIG. 1) in the forward direction (vehicle body direction) in the direction orthogonal to the axle 2 is provided on the longitudinal sides of the swing arms 3a, 3b. Along with the direction, the swing arm 3a,
A guide groove 26 in the form of a dovetail groove into which the engaging portion 25 is fitted is formed on the side surface 27 on the side opposite to the vehicle body of 3b, and the engaging portion 25 is formed in the guide groove 26 in the front-back direction (swing arms 3a, 3).
It is slidably fitted in the longitudinal direction of b). In this way, the free ends 7 of the adjustment fittings 10a and 10b on the side opposite to the vehicle body are slidably fitted in the front-rear direction so as to restrain the movement in the axle direction with respect to the swing arms 3a and 3b. Even if stress is applied to the adjustment fittings 10a, 10b in the axial direction, the adjustment fittings 10a, 10b are supported by the swing arms 3a, 3b having high rigidity. Further, the axle 2 is attached to the adjustment fittings 10a and 10b.
Even if it is removed from the vehicle, no axial misalignment occurs in the vertical direction in FIG. 1, and the axle 2 can be easily and quickly attached and detached.

For example, when the axle 2 is quickly pulled out, the engagement groove 22 of the axle and the engagement member 23 of the stopper are engaged,
A rightward force in FIG. 1 or FIG. 2 acts on the free end portion 7 of the adjustment fitting 10b on the side opposite to the vehicle body.
Since the free end portion 7 of the above is fitted to the swing arm 3b as described above, the swing arm 3b acts as a reinforcing member, and the stress acting on the free end portion 7 of the adjustment fitting 10b is the swing arm 3b. Can be supported. That is, it is not necessary to support the stress at the free end 7 of the adjustment fitting 10b.

When the axle 2 is attached, the adjustment fitting 10
Since the a and 10b are attached to the swing arms 3a and 3b in a state where the upper and lower degrees of freedom are restricted, the positioning of the axle 2 and the axle holding hole 8 of the adjustment fitting 10 can be performed only by positioning in the front-rear direction. . Also, in the front-back direction,
Positioning is performed by the adjusting bolt 11 described above.

Therefore, the axle 2 can be easily and quickly inserted.

Contrary to the embodiment shown in FIG. 1 or FIG. 2, a dovetail-shaped guide groove is formed on the side of the adjustment fittings 10a and 10b, and the side surface 27 on the side opposite to the vehicle body of each swing arm is formed. The engaging portion may be formed to constitute the restraint means.

In the present specification, the "dove groove" means a groove having a shape in which the groove width is widened on the groove bottom side (groove back side) as shown in FIG.

Further, as shown in FIG.
A cylindrical portion 28 that surrounds the swing arm 3 in a direction orthogonal to the longitudinal direction is provided at the tip portion 7a of the cylindrical portion 2a.
Even if 8 is inserted (fitted) in the rear end portion of the swing arm 3 so as to be movable back and forth, the same effect as that of the above-described embodiment can be obtained. Also, in the case of this configuration, the mounting portion is tubular,
That is, since the swing arm is surrounded in the direction orthogonal to its longitudinal direction, the stress from each direction acting on the adjustment fittings 10a and 10b is supported by the swing arm 3 having high rigidity, and thus the adjustment fittings 10a and 10b.
Can be made a thinner member, and the weight can be further reduced.

Further, the restraint means is constructed by forming the tubular portion in the embodiment shown in FIG. 5 into a channel shape having an inverted U-shaped cross section, and covering this channel portion from above the swing arm. In this case, there is an advantage that the processing can be simplified.

[0029]

According to the chain pulling device for a motorcycle according to the present invention, since the restraint means is provided at the attachment position of the adjustment fitting and the swing arm to restrain the movement in the axial direction, the adjustment fitting on the side opposite to the vehicle body side is restrained. Even if stress is applied to the free end in the direction of the axle, the swing arm having high rigidity supports this stress, so that the adjustment fitting can be made thin. As a result, the weight of the adjustment fitting can be reduced.

Further, since the restraint means restrains the vertical position of the adjusting fitting with respect to the swing arm at the same time, the adjusting fitting does not come off from the swing arm when the axle is attached or detached, and is also inserted. Misalignment is less likely to occur when wearing. Therefore, the axle can be easily and quickly attached and detached.

[Brief description of drawings]

FIG. 1 is a vertical cross-sectional view taken along the line AA of FIG. 2 showing a configuration of a rear wheel support portion of a motorcycle according to the present invention.

FIG. 2 is a plan sectional view taken along the line BB of FIG. 1 showing the configuration of the rear wheel support portion of the motorcycle, similar to FIG.

3A and 3B are diagrams showing a configuration of a mounting portion of a conventional chain pulling device, in which FIG. 3A is a horizontal cross-sectional view, and FIG. FIG. 3C is a partial horizontal cross-sectional view showing a state, and FIG. 6C is a partial horizontal cross-sectional view showing a state in which stress acts on a free end portion of the adjustment metal fitting on the axle base end side on the side opposite to the vehicle body.

FIG. 4 is a perspective view showing a configuration of a conventional U-shaped adjustment fitting.

FIG. 5 is a perspective view showing a configuration of an adjustment fitting of another chain pulling device according to the present invention.

[Explanation of symbols]

2 ... Axle 3 (3a, 3b) ... Swing arm 6 (6a, 6b) ... Chain pulling device 7 ... Free end (attachment point on the adjustment metal fitting side) 7a ... Tip ( Adjusting metal fitting side attachment point) 27 ... Side surface on the side opposite to the vehicle body (swing arm side attaching point) 10 (10a, 10b) ... Adjusting metal fitting 11 ... Adjusting bolt 25 ... Engaging portion (restraint) One of the means) 26 ... Guide groove (the other of the restraining means)

Claims (3)

[Claims] 1. A pair of left and right adjustment fittings that are attached to the rear end of each swing arm that supports the rear wheels so as to be able to move back and forth and hold both ends of the axle, and the position of the adjustment fittings in the front-rear direction on the swing arm. Equipped with an adjustment bolt to adjust
In a chain pulling device for a motorcycle for adjusting the tension of a drive chain by rotating the adjusting bolt, a restraint means for restraining movement of the adjusting bracket in the axle direction is provided at a mounting position of the adjusting bracket and the swing arm. A chain drawing device for motorcycles characterized by 2. The restraint means provides an engaging portion extending in a direction orthogonal to an axle on either one of the adjustment fitting and the swing arm along the longitudinal direction of the swing arm, and the other one of the engaging portions. The chain pulling device according to claim 1, wherein the chain pulling device is formed by providing a dovetail-shaped guide groove for restraining the joint portion in the axle direction. 3. The chain according to claim 1, wherein the restraint means is configured by providing a cylindrical portion surrounding a swing arm in a direction orthogonal to a longitudinal direction in a part of the adjustment fitting. Pulling device.