JPH0229032Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a drive chain adjustment device for motorcycles and the like.

Conventionally, drive chain adjustment devices for motorcycles, etc. are equipped with adjuster bolts for moving the rear axle on both the left and right sides of the rear end of the rear fork, and the drive chain is adjusted by operating each adjuster bolt to move the rear axle back and forth. I'm going. However, with this type of conventional adjustment device, it is necessary to screw the left and right adjuster bolts by the same amount while visually checking the scale etc. in order to move the rear axle forward and backward in parallel. Adjusting the drive chain was extremely troublesome because it involved operating the star bolt, and it was difficult to shorten the work time.

The present invention was devised to solve the above-mentioned problems, and an object of the present invention is to provide a drive chain adjustment device that can easily and quickly adjust the drive chain on one side of the vehicle. .

In order to solve the above problems and achieve the purpose, the present invention provides cams that rotate integrally with the rear axle on both the left and right sides of the rear axle, and each of the pair of cams has a continuous distance from the rear axle axis that is gradually different from the rear axle axis. cam surfaces having the same phase as each other, and engaging portions for engaging a tool are provided at one end of the rear axle, and engagement portions for engaging a tool are provided on both left and right sides of the rear end of the rear fork, respectively in front of the rear axle and capable of engaging with the cam surfaces. The rear axle is characterized in that a pin is provided in a protruding manner and the engaging portion at one end of the rear axle is rotated with a tool to continuously move the rear axle back and forth in parallel.

A preferred embodiment of the present invention will be described below with reference to the accompanying drawings.

FIG. 1 shows a left side view of the two-wheeled motor vehicle, FIG. 2 shows a perspective view of a drive chain adjustment device, and FIG. 3 shows an exploded perspective view of the same.

A head tube 2a is provided at the front end of a body frame 2 of a two-wheeled motor vehicle 1, a front fork 4 supporting a front wheel 3 is supported on the head tube 2a in a freely steerable manner, and a handle 6 is provided on a top bridge 5.

The vehicle body frame 2 includes a main pipe extending rearward from the rear upper part of the head tube 2a, a down tube 2b extending diagonally downward from the head tube 2a, a down tube blower 2c extending rearward from the lower end of the down tube, and a down tube. It consists of a center tube 2d, etc., which is inclined upwardly and forwardly from the rear end of the lower 2c.

The fuel tank 11 is installed over the main pipe of the vehicle body frame 2, and the engine 12 is mounted in the space surrounded by the main pipe, the down tube 2b, the down tube blower 2c, and the center tube 2d. A seat 13 is placed at the rear.

A pivot shaft 14 is disposed horizontally between the lower parts of the left and right members of the center tube 2d, and a rear fork 1 whose front end is pivotally connected to the pivot shaft 14 and extends rearward.
A rear wheel 16 is supported at the rear end of the wheel 5.

Guide holes 17 extending in the length direction of the rear fork 15 are formed in the left and right axle mounting portions 15a, 15a of the rear end of the rear fork 15, respectively, so that the guide holes 17 can be slid freely across the left and right guide holes 17, 17. The rear axle 21 is inserted through the rear wheel 16, and the rear wheel 16, which rotates integrally with the driven sprocket 22, is rotatably attached to the rear axle 21.
A drive chain 23 is hung between the drive sprocket on the second side and the driven sprocket 22.

On the left and right sides of the rear axle 21, cams 3 are respectively provided at the portions exposed on the outer surface of the axle mounting portion 15a so as to rotate together with the rear axle 21.
Install 1 and 31.

In the embodiment, the cams 31, 31 and the rear axle 21 are attached by meshing a female spline 31a formed on the cam 31 with a female spline 21a formed on the rear axle 21.

The cam 31 is formed with cam surfaces 31b whose distances are gradually different from the axis of the rear axle 21, and the cam surfaces 31b of the left and right cams 31, 31 have the same shape. Attach it to the rear axle 21 with the phases matching.

In the embodiment, pins 32 are provided on the outer surfaces of the left and right axle mounting portions 15a, 15a to face the front of the rear axle 21, respectively, protruding outward from the front edge portion of the guide hole 17. The pins 32, 32 of the axle attachment parts 15a, 15a are provided at the same position when viewed from the side of the motorcycle 1.

A threaded portion 21b is formed on the outer side of the left male spline 21a of the rear axle 21, a notch 21c is formed on the outer side of the threaded portion 21b, and by fastening the axle nut 33 to the threaded portion 21b, The rear wheel 16 is attached to the rear fork 15.

Since the present invention is constructed as described above, when adjusting the drive chain 23, first loosen the axle nut 33.

Next, while checking the tension state of the drive chain 23, use a tool such as a spanner to cut out the notch 21 that forms the engagement part.
c to rotate the rear axle 21.

Since the rear axle 21 is biased toward the drive sprocket due to the initial tension of the drive chain 23, the cams 31, 31 have their respective cam surfaces 31
b, 31b rotate while engaging with pins 32, 32, respectively, the shape and phase of the left and right cam surfaces 31b, 31b are the same, and the positions of the left and right pins 32, 32 are also the same, so the rear axle 21 It moves back and forth while remaining parallel to the front axle.

The tension of the drive chain 23 is adjusted by the longitudinal translation of the rear axle 21, and after achieving the desired tension, the axle nut 33 is tightened to complete the adjustment of the tension of the drive chain 23.

Therefore, according to the present invention, the tension of the drive chain 23 can be adjusted only on one side of the vehicle, and the adjustment can be performed only by rotating the notch 21c, which is the engagement part at one end of the rear axle, using a tool such as a spanner.
Drive chain adjustment can be performed simply and quickly, there is no need to visually check a scale or the like to move the rear axle in parallel as in the past, and drive chain adjustment is possible even in a dark place.

In the embodiment, the cam surfaces 31 on both the left and right sides
b, 31b were attached to the rear axle 21 with the same shape and the same phase, but if the left and right cam surfaces 31b, 31b were made different, the position of the pin 32 could be changed so that the rear axle 21 could be moved in parallel back and forth. Just shift it as appropriate.

As is clear from the above explanation, according to the present invention,
The drive chain can be adjusted on only one side of the vehicle, eliminating side-to-side adjustment errors and contributing to safe operation.Also, the adjustment can be done simply by rotating the engagement part at one end of the rear axle using a tool, simplifying the drive chain adjustment work. At the same time, the adjustment time can be shortened, and since there is no need to visually check the scale etc. during adjustment as in the conventional case, the drive chain can be adjusted even in a dark place, and many other excellent effects are exhibited. On the other hand, since the cam surface has a continuous and gradually different distance from the rear axle axis, it is possible to continuously move the rear axle back and forth in parallel, making it possible to adjust the tension of the drive chain in a stepless manner. The adjustment accuracy associated with this can be improved.

[Brief explanation of the drawing]

FIG. 1 is a left side view of the two-wheeled motor vehicle, FIG. 2 is a perspective view of the drive chain adjustment device, FIG. 3 is an exploded perspective view of the same, and FIG. 4 is a side view of the same. In the drawing, 3 is the front wheel, 15 is the rear fork, 1
6 is a rear wheel, 21 is a rear axle, 22 is a driven sprocket, 23 is a drive chain, 31 is a cam, and 32 is a pin.

Claims (1)

[Scope of utility model registration request] Cams that rotate integrally with the rear axle are provided on the left and right sides of the rear axle, and each of the pair of cams is formed with cam surfaces in the same phase that are continuously and gradually different distances from the axis of the rear axle. An engaging portion for engaging a tool is provided at the rear fork, pins are provided protruding from both left and right sides of the rear end of the rear fork in front of the rear axle and capable of engaging with the cam surface, and the engaging portion at one end of the rear axle A drive chain adjustment device for a two-wheeled motor vehicle, etc., characterized in that a rear axle is continuously moved in parallel back and forth by turning with a tool.