JPS637590Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to an improvement of a hydraulic shock absorber for two-wheeled vehicles.

As shown in Fig. 1, conventional hydraulic shock absorbers used in front forks of motorcycles, etc., have an axle mounting bracket b fixed to the lower part of the outer tube a of the hydraulic shock absorber by welding or the like. The installed oil hole c is attached to the axle mounting bracket b.
It is now located at the bottom. Therefore, if a piston e is attached to the lower end of the inner tube d and this piston e is brought into sliding contact with the inner periphery of the outer tube a, the sliding performance will deteriorate due to the effects of distortion, etc. occurring in the axle mounting bracket of the outer tube a. . Therefore, in this kind of
The inner periphery of the oil hole rod is brought into direct sliding contact with the base of the oil hole rod to alleviate the shock at the time of maximum compression, and the lower end of the inner tube d and the base end surface of the oil hole rod c form a stopper. The piston e attached to the inner tube d has to be made longer by a considerable amount, and since the inner tube d requires high machining accuracy, there is a problem in that the production cost increases.

In view of the above problems, the present invention aims to reduce production costs by configuring the base and stopper surface of the oil hole rod to be above the axle mounting bracket, thereby shortening the inner tube.

An embodiment of the present invention will now be described with reference to the drawings. FIG. 2 shows a shock absorber for a front fork of a two-wheeled vehicle showing the first embodiment. Reference numeral 1 designates a hollow cylindrical outer tube, and an axle mounting bracket 2 having an axle hole 2a formed therein is protruded from one side near the lower end of the outer tube 1, and a stepped portion 3 formed on the inner periphery of the lower end is With the peripheral edge 5 formed on the outer periphery of the lower end of the oil hole rod 4 partially fitted, and the stepped portion 6a of the cap 6 fitted externally to the protruding end of the peripheral edge 5, the outer tube 1 is inserted.
The lower end and the contact portion of the cap 6 are welded and fixed 7 to fix the oil hole rod 4.

The oil hole rod 4 has a cylindrical portion 8 extending from the peripheral edge 5.
It has a tapered outer periphery 8a whose outer periphery becomes slightly smaller in diameter toward the top, and a protruding part 9 corresponding to the inner tube 11 is formed at a position above the axle mounting bracket 2, and the protruding part 9 is approximately bell-shaped at the center. A base portion 10 is configured.

12 is a fixed rod extending from the top end of the base 10 of the oil hole rod 4 into the inner tube 11 inserted into the outer tube 1;
1 is slidable via a slide metal 13 inserted and fitted into the vicinity of the mouth end of the outer tube 1 and a piston 14 inserted and fixed to the lower end of the inner tube 11, and is slidable between the end of the fixed rod 12 and the vicinity of the upper end of the inner tube 11. A coil spring 15 inserted into the body is always elastically biased in the direction of expansion.

In addition, the inner diameter D ₁ of the piston 14 is slightly larger than the outer diameter D ₂ of the base 10 of the oil hole rod 4, and the protruding end 14a is connected to the oil hole rod 4 when the shock absorber is at maximum compression.
The shock absorber is brought into contact with the protruding step portion 9 while mitigating the impact between the shock absorber and the base portion 10 of the shock absorber, thereby regulating the compression stroke of the shock absorber.

The hydraulic shock absorber having the above structure includes the outer tube 1, the inner tube 11 and the slide metal 1.
The expansion and contraction vibrations of the outer tube 1 and the inner tube 11 are appropriately attenuated by the flow of hydraulic oil filled in the annular space A surrounded by the cylinder 3 and the piston 14 and the cylinder lower space B.

Therefore, at the time of maximum compression, the piston 14 provided at the end of the inner tube 11 fits into the base 10 of the oil hole rod 4, and the protruding end 14a contacts the protruding step 9 of the oil hole rod 4 while mitigating the impact. However, since the cylindrical part 8 of the oil hole rod 4 is extended upward and the protruding part 9 is located above the axle mounting bracket 2, the piston There is no need to extend the inner tube 11 below the inner tube 14,
The inner tube 11, which has extremely high machining accuracy, is shortened and machinability is improved.

Further, according to the above configuration, since the cylindrical portion 8 of the oil hole rod 4 has a tapered outer circumference 8a, even if the surface of the protruding portion 9 is not reliably perpendicular to the central axis of the oil hole rod 4, the outer tube 1 On the other hand, since it can be adjusted when assembled, it does not require the same processing precision as the inner tube 11 described above.

Next, FIG. 4 shows a second embodiment of the present invention, in which the cap 6 shown in the first embodiment is not provided. That is, in this embodiment, the outer diameter of the lower end 5a of the cylindrical portion 8 of the oil hole rod 4a is formed within the range of the insertion tolerance with respect to the outer tube 1, and after the oil hole rod 4a is inserted,
The lower end 5a and the inner peripheral part of the outer tube 1 are welded and fixed 7, and at this time, the protruding part 9 of the oil hole rod 4a
is fixed so as to be located above the axle mounting bracket 2 as in the first embodiment.

Furthermore, FIG. 5 shows a third embodiment of the present invention, in which the cap 6 is not provided like the second embodiment. The outer diameter of the peripheral edge 5b formed at the lower end of the cylindrical portion 8 of the oil hole rod 4b is approximately the same as the outer diameter of the outer tube 1. are welded and fixed 7 at the abutting position, and the protruding step portion 9 is located closer to the axle mounting bracket 2.

As explained above, the present invention includes an outer tube that is movably interposed, and an oil hole rod that cushions the impact when the outer tube is fully compressed.
Further, in a hydraulic shock absorber for a two-wheeled vehicle having an axle mounting bracket fixed to the side surface of the outer tube, an abutment step portion is formed at the upper part of the oil hole rod to collide with a piston provided at the tip of the inner tube, and A vertically elongated cylindrical part is provided below the corresponding protrusion, and the cylindrical part is inserted into the lower part of the outer tube, and the lower edge of the cylindrical part is welded and fixed to the lower end of the outer tube. The stepped portion is supported so as to be located above the axle mounting bracket.

On the other hand, in conventional shock absorbers of this kind, for example, as in the hydraulic shock absorber for motorcycles disclosed in JP-A-56-163988, the axle mounting bracket fixed to the outer tube is attached to the protruding part of the oil hole rod. This is done by integrally molding the protruding part and the axle mounting bracket, or by using a cap, but the present invention uses a vertically long tube that supports the protruding part. A shaped part is provided, this is inserted and welded to the lower end of the outer tube, the protruding part is supported upwardly, and the axle mounting bracket is directly welded to the outer tube below the protruding part. Even if an impact load is received from the wheel side, it is received by the entire outer tube, so the load is not concentrated in one place, and the strength can be improved. In addition, not only does the number of parts need to be reduced, but since there is no welded part in the middle of the outer tube, it is possible to maintain the aesthetic appearance and is effective in terms of strength. Together, the practical benefits are extremely significant.

[Brief explanation of the drawing]

The drawings show an embodiment of the hydraulic shock absorber for two-wheeled vehicles according to the present invention. Figure 1 is a partially cutaway front view of a conventional hydraulic shock absorber, and Figure 2 is a half-cut view of the hydraulic shock absorber showing the first embodiment. Front sectional view, Figure 3 is an enlarged view of the same main parts,
FIGS. 4 and 5 are half-cut sectional views of essential parts showing the second and third embodiments, respectively. 1...Outer tube, 2...Axle mounting bracket,
3... Stepped portion, 4, 4a, 4b... Oil hole rod, 5, 5
b...periphery, 5a...bottom end, 6...cap, 8
...Cylindrical part, 8a...Tapered outer periphery, 9...Protruding step part, 10...Step part, 11...Inner tube, 1
2...Fixed rod, 13...Slide metal, 1
4...Piston, 15...Coil spring.

Claims (1)

[Scope of utility model registration request] While the inner tube is movably interposed within the outer tube, an oil hole rod is attached to the lower end of the outer tube to reduce the impact when the inner tube is fully compressed, and an axle mounting bracket is fixed to the side of the outer tube. In the hydraulic shock absorber for a two-wheeled vehicle, the lower end of the oil hole rod is provided with an abutment step that abuts against the piston provided at the tip of the inner tube, and is provided extending downward from the abutment step. The cylindrical part is inserted into the lower part of the outer tube, and the lower edge of the cylindrical part is welded and fixed to the lower end of the outer tube, while the longitudinal length of the cylindrical part holds the stepped part above the axle mounting part. A hydraulic shock absorber for two-wheeled vehicles, which is characterized by: