JPH0454098B2 - - Google Patents

Description

[Detailed description of the invention] Technical field The present invention relates to a cylindrical shock absorber for a vehicle.

Background technology As a cylindrical shock absorber for vehicles, Utility Model No. 57-141247
BACKGROUND OF THE INVENTION A shock absorbing device disclosed in Japanese Utility Model Publication No. 57-130033 is known. In such a shock absorber, the exposed portion of the inner tube or piston rod is surrounded and protected by a cylindrical covering member, and the inside of the cylindrical covering member is communicated with the atmosphere through a conduit. ing.

In a shock absorbing device having such a structure, when the cylindrical covering member expands and contracts due to shock absorption, dust floating in the air is also sucked into the interior of the cylindrical covering member along with the air. Therefore, the dust seal provided to prevent the dust from entering the outer tube is required to have high dustproof properties and durability.

SUMMARY OF THE INVENTION In view of the above-mentioned points, it is an object of the present invention to provide a shock absorbing device that prevents dust from entering into the interior of the cylindrical covering member, and has excellent dustproof properties.

In the cylindrical shock absorber for a vehicle according to the present invention,
The interior of the cylindrical covering member that surrounds the opening of the cylindrical member into which the rod-like member is inserted is in contact with the outer surface of the cylindrical member or the rod-like member near the end of the cylindrical covering member. An annular air filtration member is interposed between the member and the annular air filtration member, one side of the annular air filtration member faces an internal space surrounded by the cylindrical covering member, and the other side of the annular air filtration member is configured to face a plurality of communication holes that communicate with the outside air.

Embodiments Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.

FIG. 1 shows a telescopic shock absorber 1 used in a front fork of a motorcycle as an embodiment of the present invention. In the shock absorber shown in FIG. 1, a hollow rod-shaped inner tube 3 is fitted into a cylindrical bottom case 2. As shown in FIG. For example, a coil spring (not shown) and a piston (not shown) having an orifice are disposed inside the bottom case 2 and the inner tube 3, and oil (not shown) is injected into the bottom case 2 and the inner tube 3. The longitudinal impact applied to the shock absorber 1 is damped by the cooperative action of the coil spring, piston, and oil.

Bottom case 2 with inner tube 3 inserted
An annular dust seal S is fixed to the bottom case 2 and is in close contact with the inner tube 3.
is provided. The dust seal S prevents dust from entering the inside of the bottom case 2. Bottom case 2 with dust seal S
The frontage is surrounded by a cylindrical covering member 4, and the cylindrical covering member 4 has one end fastened to the outer surface of the bottom case 2 and the other end fastened to the outer surface of the inner tube 3 protruding from the bottom case 2. It is fixed by attached bands 5 and 6. The cylindrical covering member 4 is made of rubber, for example, and has a bellows shape as shown, and has a highly elastic structure.

As shown in FIGS. 2a and 3, for example, an annular recess 2a is provided in the circumferential direction near the fixed portion of the cylindrical covering member 4 on the outer surface of the bottom case 2, and the recess 2a is filled with air. An annular filter 7 is fitted as a filtering member. Since the recess 2a is provided near the fixed part of the cylindrical covering member 4, the filter 7 receives the fixing force of the fixed part and fixes the cylindrical covering member 4.
and the bottom case 2 are compressed in the radial direction,
Bottom case 2, cylindrical covering member 4, and filter 7
This can prevent a gap from forming between the two.

A chamber 8 formed inside the cylindrical covering member 4
communicates with the atmosphere only through a filter 7, as shown in FIGS. 2 and 3. In order to communicate the chamber 8 with the atmosphere, in the case of the embodiment shown in FIG. In the case of the alternative embodiment shown in the figure, the recess 2a
A groove 2b communicating with the bottom case 2 is provided on the outer surface of the bottom case 2. The chamber 8 expands and contracts as the shock absorber 1 expands and contracts during buffering. During the expansion and contraction, the chamber 8 takes in and releases air through the filter 7 from the flow hole 4a or the groove 2b. When the chamber 8 takes in air, the filter 7 removes dust contained in the air.

Further, as shown in FIGS. 1 and 4, a filter 7 may be interposed between the outer surface of the inner tube 3 and the cylindrical covering member 4. In this case as well, since the filter 7 is provided near the part of the cylindrical covering member 4 that is fixed to the inner tube 3, the filter 7 is moved between the cylindrical covering member 4 and the inner tube 3 by receiving the fixing force of the fixed part. The pressure is narrowed in the radial direction to prevent a gap from forming between the inner tube 3 and the cylindrical covering member 4 and the filter 7. The filter 7 shown in FIG. 4 is covered with a collar 9 on its outer surface. When the shock absorber 1 absorbs shock and contracts, the collar 9 is attached to the cylindrical covering member 4.
This prevents the filter 7 from being crushed in the direction of contraction of the shock absorber 1. The collar 9 is provided with a hole 9a that communicates with the communication hole 4a formed in the cylindrical covering member 4, and the chamber 8 communicates with the atmosphere via the filter 7. Filter 7 as chamber 8 expands and contracts
The effect of is as described above.

It is preferable to form the filter 7 from a sponge-like porous material made of a highly hygroscopic synthetic resin, since moisture in the air sucked into the chamber 8 can be removed.

In the above-described embodiment, the recess 2a and the filter 7 have an annular shape extending all around the outer surface of the bottom case 2, but the shapes of the recess and the air filter member in the present invention are not limited to this. .

Effects of the Invention As explained above, in the cylindrical shock absorber for a vehicle according to the present invention, air filtration is provided between the outer surface of the cylindrical member or rod-shaped member formed as a bottom case and the cylindrical covering member. The member is annular,
Furthermore, a sufficient breathing function can be obtained by supporting and fixing with a member provided with a plurality of communication holes to increase the area of contact with the outside air and increasing the passage area.

Thereby, it is possible to prevent dust contained in the air from entering the inside of the cylindrical covering member, resulting in excellent dustproof properties. As a result, the close contact force of the dust seal interposed between the rod-shaped member formed as an inner tube and the cylindrical member can be reduced, and the frictional resistance between the dust seal and the rod-shaped member can be reduced. , the durability of the dust seal is improved, the buffering action becomes smoother, and the operating performance is improved.

In addition, by configuring the filtration member as an independent annular member, when assembling the annular air filtration member, the annular air filtration member is first fitted to the outer surface of the rod-shaped member or the cylindrical member, and then the annular air filtration member is It is also possible to ensure ease of assembling work, in that a configuration as a breather is achieved simply by fitting the cylindrical covering member in contact with the outer circumferential surface of the member.

[Brief explanation of the drawing]

Fig. 1 is a diagram showing a vehicle shock absorbing device according to the present invention, Fig. 2 is a diagram showing part A in Fig. 1 in detail, and Fig. 3 is a diagram showing a different embodiment from Fig. 2. , FIG. 4 is a detailed view of section B in FIG. 1. Explanation of symbols of main parts, 1... Cylindrical shock absorber for vehicle according to the present invention, 2... Bottom case, 3...
Inner tube, 4... cylindrical covering member, 7... filter, S... dust seal.

Claims (1)

[Claims] 1 A cylindrical shock absorber for a vehicle that reduces impact by controlling the relative movement of a cylindrical member and a rod-shaped member fitted therein, which is fixed to the outer surface of the cylindrical member and the rod-shaped member. It includes a cylindrical covering member that surrounds an opening of the cylindrical member into which the rod-like member is fitted, and the outer surface of the cylindrical member or the rod-like member and the An annular air filtration member is interposed between the cylindrical enveloping member, one side of the annular air filtration member faces an internal space surrounded by the cylindrical enveloping member, and the annular air filtration member A cylindrical shock absorber for a vehicle, characterized in that the other side faces a plurality of communication holes that communicate with outside air.