JPS621468Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to an improvement of a hydraulic shock absorber for a front fork of a two-wheeled vehicle, etc., which is equipped with a damping force adjustment mechanism.

Conventionally, there are hydraulic shock absorbers for front forks of two-wheeled vehicles, etc., which have a damping mechanism installed in the inner tube and have an oil passage outside the wall of the outer tube to adjust the damping force (see Figure 1). , an oil passage b for damping force adjustment installed in parallel with the outer tube a.
In order to protect the shock absorber from external forces such as collisions, a part of the outer tube a protrudes to form a protective wall c and is covered with a cover member d. Therefore, the dimensions from the axis of the shock absorber are large and the weight increases. In addition, when used in a motorcycle or the like, air resistance increases during running, resulting in power loss.

Therefore, in order to solve these problems, for example,
Utility Model Publication No. 32-13924 and Japanese Unexamined Patent Publication No. 49-38339 have already been proposed, but in constructing the bypass passage bored in the bulge of the outer tube, these methods Multiple passages opening to the outside must be drilled, which requires parts to close the passages, which only increases the number of parts and the time required for assembly. It is also necessary to consider oil leakage, etc.

Furthermore, the damping force adjustment parts are arranged in parallel in the longitudinal direction of the outer tube, which makes manual adjustment extremely difficult because the outer tube gets in the way, and there is a problem that adjustment cannot be done without the use of tools. It was hot.

In view of the above-mentioned problems, the present invention not only reduces weight and reduces the size of the protrusion to reduce loss due to air resistance, but also eliminates the adjustment hole as the only hole that opens from the protrusion of the outer tube to the outside. Moreover, a damping force adjustment mechanism is inserted in the adjustment hole to eliminate the existence of an extra hole that goes out to the outside, and at the same time, it is possible to easily adjust the damping force without using tools etc. This is what I did.

Now, one embodiment of the hydraulic shock absorber of the present invention will be described with reference to the drawings. FIG. 2 is a partially cutaway front view of the outer tube, and FIG. 3 is a half-cut sectional view of the main part in an assembled state.

The outer tube 1 has a matte finish shown in FIG. 2 which is cast using a shell core, and after casting, the inner wall of the outer tube is mechanically finished to form the cylinder inner wall 2. Due to its casting, the outer tube bulge 3
At the same time, a bypass oil passage 4 is formed at the upper end thereof, and an adjustment hole 5 is formed at the upper end thereof, and a port opening 6 is formed at the lower end thereof. The adjustment hole 5 projects upwardly from the outer tube 1, and its outer end forms an end surface 2a perpendicular to the adjustment hole 5. Further, the port opening 6 has an arcuate joint (arrow A) with the cylinder inner wall 2, and the bypass oil passage 4 becomes an inclined portion 4a extending toward the adjustment hole 5 from the middle.

In the cast outer tube 1 described above, the adjustment hole 5 is inclined and the intersection angle with the inclined part 4a of the bypass oil passage 4 is an obtuse angle, so it is easy to remove casting sand, etc., and a cleaning tool such as a brush cannot be inserted. It becomes an easy shape. This outer tube 1 is machined and constructed as shown in FIG. 7 is adjustment hole 5
This is an adjustment rod that is rotatably inserted into a shaft hole 5a bored in the shaft hole 5a, and an O-ring 8 is fitted into a concave groove provided on the outer periphery of the midsection of the adjustment rod 7, and the outer side of the shaft hole 5a is At the same time, a stay ball 9 is loosely fitted into a small hole drilled in the flange 7a that loosely fits into the stepped portion 5b, and a spring is applied to press the stay ball 9 via an annular leaf spring 10. The outer end of the presser foot 11 is fixed to the stepped portion 5b by a snap spring 12. Orifices 14, 14, etc. having different hole diameters, which communicate the through hole 13 opened from the lower end with the inclined part 4a of the bypass oil passage 4, are equally spaced on the peripheral wall of the adjustment rod 7, and are formed in the stepped part 5b. Moderation groove 15
The stay ball 9 is press-fitted into the position, and the adjustment rod 7 is rotated appropriately to select the bypass oil passage 4 and the orifice 14 of the adjustment hole 5. Further, reference numeral 17 denotes an operating knob fixedly installed on the protruding end 7b of the adjustment rod 7, which is designed to fit against the end surface 2a of the adjusting rod 7, and a peripheral portion of the operating knob 17 corresponds to the orifice 14. The adjustment position display 18 is engraved.

An inner tube 19 is telescopically inserted into the inner wall 2 of the cylinder.
At the lower end of 9, a main piston 21 with a non-return valve 20 is inserted into a hollow rod 22, and a through hole 23 bored in the inner tube 19 and a bypass oil passage 4 are inserted into the hollow rod 22.
The spaces B and C above and below the inner tube 19 form a damping force generating oil passage.

The hydraulic shock absorber having the above structure is manufactured by turning the operating knob 17 of the damping force adjustment mechanism and adjusting the orifice 14 of the adjustment rod 7.
is selected, and the flow rate of the bypass oil passage 4 is adjusted to adjust the expansion/contraction speed of the inner tube 19 having the main piston 21. Since this bypass oil passage 4 is integrally formed with the outer tube 1 by casting, the weight is reduced because this part forms a smooth bulge 3 that slightly protrudes in the outer diameter direction of the outer tube 1. At the same time, it has a shape with low air resistance. Furthermore, since the adjustment hole 5 is tilted upward with respect to the outer tube 1, the operation knob 17 faces diagonally upward, making adjustment easier.

As explained above, the hydraulic shock absorber according to the present invention not only is lightweight, reduces air resistance, and reduces output loss, but also adjusts the damping force in the adjustment hole tilted upward with respect to the outer tube. Since the mechanism is included, not only can the damping force be easily adjusted manually, but there is no extra hole to form a bypass passage, so there is no need for any parts to block the hole. The practical effects are extremely large, such as reducing the number of parts and improving ease of assembly, as well as eliminating the need to take oil leakage into account.

[Brief explanation of drawings]

The drawings show an embodiment of the hydraulic shock absorber of the present invention. Figure 1 is a partially cutaway front view of the main parts of a conventional device, Figure 2 is the outer tube of the hydraulic shock absorber of the present invention, and Figure 3 is the same assembly. It is a half-cut sectional view of the main part in the state. 1...Outer tube, 3...Outer tube bulge, 4...Bypass oil passage, 5...Adjustment hole, 7
...Adjustment rod, 9...Steal ball, 10...
Leaf spring, 12...Snat spring, 13, 23...
...through hole, 14...orifice, 15...moderation groove,
17...Operation knob, 19...Inner tube, 2
1... Main piston, 22... Hollow rod.

Claims (1)

[Scope of utility model registration request] A bypass passage formed in the outer tube to communicate the upper and lower oil chambers divided by the piston is formed by an adjustment hole protruding diagonally upward from the inner surface of the outer tube and a passage extending from one side of the outer tube toward the adjustment hole. What is claimed is: 1. A hydraulic shock absorber characterized in that the passages and the adjustment hole intersect at an obtuse angle, and a damping force adjustment mechanism is interposed in the adjustment hole.