JPS6337357Y2 - - Google Patents

Description

[Detailed Description of the Invention] This invention relates to an improvement of a spring initial load adjustment device in a front fork of a two-wheeled vehicle.

Generally, the front fork of a two-wheeled vehicle is constructed by combining a shock absorber and a spring. Particularly in the case of high-performance two-wheeled vehicles, a spring initial load adjustment device is provided to adjust the stiffness of the spring depending on the load and road surface conditions. FIG. 1 shows a front fork 2 on one side of a two-wheeled vehicle, which has a conventional spring initial load adjusting device 1 of this type. 3 is an outer cylinder, 4 is a hole for attaching the outer cylinder 3 to the axle of a two-wheeled vehicle, 5 is an inner cylinder that can slide inside the outer cylinder 3, and inside the inner cylinder 3 and outer cylinder 5 are hydraulic oil and high pressure. It is filled with gas. 6 is a spring arranged inside the inner cylinder 5. The above device 1
In the figure, 7 is a cylindrical fork bolt fixed to the upper end of the inner cylinder 5, and a multistage cam groove 8 is provided in the peripheral wall of the lower end. Reference numeral 9 denotes an adjustment pipe which is fitted in the cylindrical hole of the cylindrical fork bolt 7 so as to be movable in the axial direction and rotatable, and has an integral hexagonal head 10 at its upper end. Pins 11 on both sides in the radial direction protrude from the peripheral wall of the adjustment pipe 9,
It engages with opposing cam grooves 8 of the fork bolt 7. An annular seat 12 is brought into contact with the lower end of the adjustment pipe 9 by the force of a spring 6. To provide the desired initial load, push the hexagonal head 10 downwards to force the pin 11 of the adjusting pipe 9 onto the fork bolt 7.
When the hexagonal head 10 is rotated, for example, to the right in FIG.
passes over the adjacent protrusion and enters the next cam groove 8 located at a lower position. As a result, the adjusting pipe 9 moves upward by the difference in height between the adjacent cam grooves 8, and therefore the seat 12 moves upward. In this way, the initial load of the spring 6 can be adjusted by the number of stages of the opposing cam grooves 8 provided in the fork bolt 7.

However, a considerable amount of force is required to push the adjusting pipe 9 directly downward and rotate it against the force of the spring 6, making it difficult to adjust the initial spring load. Another problem was that the initial spring load could only be adjusted by the number of steps on the cam projection of the fork bolt.

This invention proposes a spring initial load adjustment device for a front fork of a two-wheeled vehicle with the aim of eliminating the above-mentioned drawbacks. shaped inner fork bolt,
a stopper ring fitted onto the lower end of a male screw threaded on the outer periphery of the lower part of the inner fork bolt;
a cylindrical fork bolt that is screwed onto the upper end of the inner cylinder and has a female thread on the inner periphery of the lower end that engages with the male thread; and a cylindrical fork bolt that is inserted between the fork bolt and the inner fork bolt and the inner periphery of the lower end. and a cylindrical lock nut having a female thread that engages with the male thread.

Hereinafter, one embodiment of this invention will be described based on FIG. 2.

Reference numeral 13 denotes an inner cylinder that is slidably fitted into a lower outer cylinder (not shown), and the spring initial load adjusting device 14 of this invention is provided at the upper end of the inner cylinder 13. A cylindrical inner fork bolt 17 is inserted into the center of the inner cylinder 13 from above with its lower end supporting the upper end of the spring 15 and in contact with the upper surface of the seat 16 loosely fitted into the inner cylinder 13. The inner fork bolt 17 is provided with a male thread 18 on its lower outer periphery. On the other hand, a cylindrical fork bolt 19 for closing the inner upper end of the inner cylinder 13 is screwed into the inner cylinder 13, and a female thread 20 carved on the inner periphery of the lower end of the fork bolt 19 is connected to the inner fork bolt. It is screwed into a male thread 18 of 17. Further, a cylindrical lock nut 21 is provided to be inserted into the cylindrical gap formed between the fork bolt 19 and the inner fork bolt 17, and the inner fork bolt 21 is provided on the inner periphery of the lower end of the lock nut 21, similar to the fork bolt 19. It has a female thread 22 that screws into the male thread 18 of 17. In addition, 23 and 24 are a stopper collar and a stopper ring that are fitted onto the lower end of the inner fork bolt 17 in order to prevent the inner fork bolt 17 from coming off upward, 25 is an O-ring, and 26 is an air Valve cap shown.

When adjusting the initial load of the spring in the device configured as described above, first tighten the lock nut 21.
Turn the inner fork bolt 17 to loosen it, turn the inner fork bolt 17 to raise and lower it, and stop it at a predetermined position using the scale engraved on the outer periphery of the upper part of the inner fork bolt 17. Then, turn the lock nut 21 to tighten the inner fork bolt 17. Fix the position of the bolt 17. By this operation, the spring seat 16 that contacts the lower end of the inner fork bolt 17 also moves up and down, and is then fixed at a predetermined height, thus completing the adjustment of the initial load of the spring 15. At this time, since an O-ring is interposed between the fork bolt and inner fork bolt and the lock nut, sealing performance is ensured within the range where the lock nut and inner fork bolt move up and down, and the outer periphery of the spring seat and the inner periphery of the inner cylinder are secured. Because there is a gap between the two, adjusting the initial load of the spring has little effect on the spring characteristics of the enclosed high-pressure gas.

According to this invention, as described above, the male thread on the outer periphery of the lower part of the inner fork bolt is screwed into the female thread threaded on the inner periphery of the lower end of the fork bolt that is screwed into the upper end of the inner cylinder, and the inner fork bolt is rotated. By raising and lowering the spring seat, the spring seat that contacts the lower end of the spring seat is raised and lowered, and the spring is lifted and lowered without affecting the spring characteristics of the enclosed high-pressure gas and without impairing the sealing performance against high-pressure gas or hydraulic oil. Since it is a mechanism to adjust the initial load, the force required for adjustment is very small compared to conventional ones, and it is easy.
Furthermore, compared to conventional stepped cams, this provides an excellent effect in that continuous adjustment is possible. Furthermore, if a scale is engraved on the outer periphery of the upper part of the inner fork bolt, the adjustment range and position of the initial load of the spring can be clearly seen at a glance, which is very useful.

[Brief explanation of the drawing]

FIG. 1 is a partially longitudinal front view showing a front fork of a two-wheeled vehicle having a conventional spring initial load adjusting device, and FIG. 2 is a partially longitudinal front view showing an embodiment of this invention. In the figure, 13...Inner cylinder, 14...Spring initial load adjustment device, 15...Spring, 16...Spring seat, 17...Inner fork bolt, 18...Male thread, 19...Fork bolt,
20, 22...female thread, 21...lock nut,
23...stopper collar, 24...stopper ring.

Claims (1)

[Scope of utility model registration request] In the front fork of a two-wheeled vehicle, an outer cylinder is slidably fitted from below into an upper inner cylinder, and shock is cushioned by high-pressure gas and hydraulic oil sealed inside and a telescopically interposed spring.
A cylindrical inner fork bolt whose lower part is inserted into the center of the inner cylinder from above and its lower end abuts against a spring seat, and a stock fitted onto the lower end of a male screw threaded on the outer periphery of the lower part of the inner fork bolt. a cylindrical fork bolt that is screwed onto the upper end of the inner cylinder via an O-ring and has a female thread on the inner periphery of the lower end that engages with the male thread; and the fork bolt and the inner fork bolt. A spring initial load adjusting device comprising: a cylindrical lock nut which is inserted between the lock nuts through O-rings, and has a female thread on the inner periphery of the lower end that engages with the male thread.