JP2561267Y2 - Bottom structure of shock absorber - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial application field) The present invention relates to a bottom structure of a shock absorber.

(Prior Art) Conventionally, as a bottom structure of this type of shock absorber, for example,
The one described in Japanese Utility Model Laid-Open No. 56-62446 is known.

In this apparatus, a bottom plate is welded to a reservoir tube end of a shock absorber, and a bottom body is mounted on the bottom plate.

(Problems to be Solved by the Invention) However, in the conventional apparatus having such a structure, the bottom plate is formed only as a mounting table for the bottom body, so that the lower part of the bottom body communicates with the reservoir chamber. It is necessary to provide a groove or a leg at the bottom of the bottom body in order to make the structure of the bottom body complicated, and the bottom body is usually sintered and molded.
Due to the formation of the grooves or the legs, the sintering density was not stable, and the forming such as cutting to obtain the final shape was troublesome.

In addition, since the reservoir tube and the bottom plate are separate bodies, a step of forming the bottom plate separately from the reservoir tube and then welding the two together is required, which has a disadvantage of being expensive.

In order to solve such a problem, the present applicant has devised a bottom structure (hereinafter, referred to as prior art) shown in the specification and drawings of Japanese Patent Application No. 1-56365.

This prior art has a structure in which a bottom portion is formed integrally and continuously from a reservoir tube, and a bottom body is supported by a plurality of embosses provided on the bottom portion.

With such a structure, in the prior art, a passage can be formed between the embosses, the formation of a groove or a leg in the bottom body can be omitted, the structure can be simplified, and the sintering density during molding can be reduced. It is possible to provide an inexpensive shock absorber that can be formed stably and can be formed without the need for cutting or the like.

As described above, although the prior art can obtain excellent effects, however, since the structure for centering the bottom body is only the tapered surface of the embossed portion, the angle of the seating surface of the bottom body is reduced. If it is small (flat), the outer cylinder and the bottom body may be misaligned.

Conversely, if the angle of the seating surface is increased (standing direction),
Although shaft misalignment is less likely to occur, on the other hand, there is a possibility that variation in the axial dimension between the outer cylinder, the bottom body, and the cylinder tube having the bottom body at the bottom may increase.

The present invention has been made in view of such a conventional problem. In addition to providing a bottom structure of an inexpensive shock absorber which can simplify the structure of a bottom body and does not require welding, etc. It is an object of the present invention to provide a shock absorber bottom structure in which the axial displacement between the outer cylinder, the bottom body, and the cylinder tube is less likely to occur while preventing the axial deviation between the shock absorber and the bodom body.

(Means for Solving the Problems) In order to achieve the above object, in the bottom structure of the shock absorber according to the present invention, a bottom body is provided at the bottom of the cylinder tube, and a reservoir tube is provided outside the cylinder tube. Thus, a reservoir chamber is formed between the reservoir tube and the cylinder tube, a bottom portion is formed continuously and integrally with the reservoir tube, and a bottom body lower chamber is formed between the bottom portion and the bottom body. ,
A plurality of embosses capable of supporting the bottom surface of the bottom body in the axial direction are formed at the bottom of the reservoir tube, and a passage communicating between the reservoir chamber and the bottom body lower chamber is formed between the embosses. A plurality of guide protrusions are formed on the inner surface side of the tube bottom to support the bottom body in the radial direction and to be disposed coaxially with the reservoir tube, and each guide protrusion is extended in the axial direction to form the bottom. A means is provided in which a straight portion that has a width in the axial direction and abuts on the outer periphery of the body is formed.

(Operation) When this cylinder tube is inserted into the reservoir tube so that the bottom body provided at the bottom of the cylinder tube is supported by the bottom of the reservoir tube, the bottom body at the bottom is formed on the inner surface side of the bottom of the reservoir tube. The outer periphery of the bottom body is arranged in a coaxial position without being inclined with respect to the reservoir tube by abutting the outer periphery of the bottom body with a width in the axial direction to the linear portion of each guiding convex portion, and In the coaxial state, the bottom body is supported by a plurality of embosses.

In the state where the bottom body is supported by the above-mentioned emboss, a passage between the lower part of the bottom body and the reservoir chamber is formed between these embosses.

Further, since the reservoir tube and the bottom portion are continuously integrated, the step of fixing the both by welding or the like can be omitted.

(Example) Hereinafter, an example of the present invention will be described in detail with reference to the drawings.

FIG. 1 shows a bottom structure of a shock absorber according to one embodiment of the present invention. In the drawing, reference numeral 10 denotes a reservoir tube having a substantially spherical bottom portion 11 continuous with a tube portion.
A plurality of embossed portions 13 are provided at equal intervals in the circumferential direction in the vicinity of a connection portion with the tube portion 12, and a protruding end of each embossed portion 13 is provided with a taper 14 that forms a conical surface in relation to other protruding ends. ing. In forming the bottom 11, the end of the tube 12 is closed (for example,
A molding method such as spinning shown in JP-A-59-125220) is performed, and an embossing die is inserted into the tube portion 12 while being in contact with the bottom portion 11 while there is residual heat by the clawsin molding. The embossed portion 13 is formed by pressing.

Further, as shown in FIG. 2 which is a cross-sectional view taken along the line II-II of FIG. 2, these embossed portions 13 are formed at three places on the bottom portion 11.

Returning to FIG. 1, reference numeral 20 denotes a bottom body that fits and closes the lower end of the cylinder tube 30, closes the cylinder tube 30, and sits on the bottom 11 of the reservoir tube 10 to position and hold the cylinder tube 30 in the reservoir tube 10. This bottom body 20
Has a seating portion 21 having a shape matching the taper 14 of the plurality of embossed portions 13 of the reservoir tube 10 and a fitting portion 22 fitted to the lower end of the cylinder tube 30. Further, the bottom body 20 has an extension-side passage 23 and a compression-side passage 24 communicating vertically, and the extension-side check valve 25 is provided at an open end inside the cylinder tube 30 of the extension-side passage 23. At the middle and lower open ends, the pressure side disc valve
26 are provided, and these two valves are
25 and 26 are fixed to the bottom body 20.

Reference numeral 40 denotes a reservoir tube 10 for a vehicle suspension member (not shown) and an insulator (eye bush) 41.
Shows the mounting ring mounted through the reservoir tube 10
It is attached to the bottom 11 by welding.

Reference numeral 18 denotes a guide protrusion for arranging the bottom body 20 at a position coaxial with the reservoir tube 10, and the guide protrusion 18 is provided at a position near a connection portion between the bottom 11 and the tube portion 12. It is formed so as to protrude inside the tube 10, and is formed at three places between the embossed portions 13 as shown in FIG. The guide projection 18 can be formed by the same processing method as the embossed portion 13. 2, the dotted line indicates the outer periphery of the bottom body 20.

In the drawing, reference numeral 15 denotes a reservoir, and 16 denotes a space between the embossed portions 13.
A passage 17 is formed at a location, a bottom body lower chamber formed between the lower portion of the bottom body 20 and the bottom 11 of the reservoir tube 10, and a piston lower chamber 31 below a piston (not shown) in the cylinder tube 30.

The operation of the embodiment of the present invention having the above configuration will be described below.

In manufacturing the shock absorber, when assembling the bottom body 20 and the cylinder tube 30 to the reservoir tube 10, first, the fitting portion 22 of the bottom body 20 is fitted to the bottom of the cylinder tube 30, and the bottom body 20 is connected to the cylinder tube. Assemble coaxially with 30. In this assembled state, the bottom body 20 and the cylinder tube 30 are inserted into the reservoir tube 20.

When the bottoms of the bottom body 20 and the cylinder tube 30 reach the bottom 11 of the reservoir tube 10, the outer periphery of the bottom body 20 comes into contact with the guide projections 18 provided at three places on the bottom 11, and the bottom body 20 Are arranged coaxially with the reservoir tube 10, and are fixed when the seating portion 21 of the bottom body 20 comes into contact with the tapered surface 14 of the embossed portion 13.

As described above, the bottom body 20 and the cylinder tube 30 in the integrally assembled state are connected to the reservoir tube by the guide projection 18.
It is arranged coaxially with 10, so the embossed part 13
Even if the inclination of the tapered surface 14 is made shallow, no axial deviation occurs.
When the inclination of the tapered surface 14 is made shallow in this way, variations in the axial dimensions of the bottom body 20, the cylinder tube 30, and the reservoir tube 10 are less likely to occur.

During the extension stroke of the shock absorber, a piston (not shown) rises in the cylinder tube 30, the pressure in the piston lower chamber 31 decreases, and the passage between the reservoir chamber 15 and the emboss 13, the bottom body lower chamber 17, the extension passage 23 The hydraulic fluid is guided to the extension-side check valve 25 via the, and the extension-side check valve 25 is opened to be introduced into the piston lower chamber 31. In this case, the extension side check valve 25 does not normally generate a damping force.

During the compression side stroke of the shock absorber, a piston (not shown) moves down in the cylinder tube 30, the pressure in the piston lower chamber 31 increases, and the hydraulic fluid in the piston lower chamber 31 pushes the compression side disc valve 26 through the compression side passage 24. While opening, it flows into the bottom body lower chamber 16 and is discharged to the reservoir chamber 15 through the passage 16 between the embosses 13, and generates a compression-side damping force when the compression-side disc valve 26 is pushed open.

In addition, the reservoir tube 12 in the above embodiment is formed by closing and forming the bottom portion 11 using a tubular material.To obtain the tubular material, the coil material is cut, roll-formed, and the roll end portion is formed. Can be obtained by welding and post-finishing, and a tubular material can be provided at low cost.

The bottom 11 formed in this manner has an embossed portion.
13 and the guide projection 18 are formed, so that the bottom 1
1. Consequently, the strength of the reservoir tube 10 is improved.

(Effects of the Invention) As described above, according to the bottom structure of the shock absorber of the present invention, a guide projection for guiding the bottom body to a position coaxial with the reservoir tube is formed on the inner side of the bottom of the reservoir tube. When the bottom body is disposed at the bottom of the reservoir tube, the bottom body is arranged coaxially with the reservoir tube by the projection for guiding, so that the axis of the reservoir tube and the bottom body are misaligned. Is less likely to occur, and the axial dimensions of the reservoir tube, the bottom body, and the cylinder tube are less likely to vary.

In addition, since the bottom portion is formed integrally with the reservoir tube and the bottom body is supported by a plurality of embosses provided on the bottom portion, a passage is formed between the embosses. In addition to simplifying the structure by omitting the formation of the groove or the leg, the sintered density can be stabilized at the time of molding, and the molding can be performed without the need for cutting or the like, thereby providing an inexpensive shock absorber. can get.

Furthermore, since the embossing and the guide projection are integrally formed on the bottom of the reservoir tube, a synergistic effect that the strength of the bottom of the reservoir tube is improved can be obtained.

[Brief description of the drawings]

FIG. 1 is an overall sectional view showing a bottom structure of a shock absorber according to one embodiment of the present invention, and FIG. 2 is a sectional view of FIG.
It is II-II sectional drawing. 10 Reservoir tube 11 Bottom part 13 Embossed part 18 Guide protrusion 20 Bottom body 30 Cylinder tube 40 Mounting ring

 ──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-52-37551 (JP, A) JP-A-53-142724 (JP, A) JP-A-59-125221 (JP, A)

Claims (1)

(57) [Scope of request for utility model registration] A bottom body provided at a bottom portion of the cylinder tube; a reservoir tube provided outside the cylinder tube; a reservoir chamber formed between the reservoir tube and the cylinder tube; And a bottom portion is integrally formed, a bottom body lower chamber is formed between the bottom portion and the bottom body, and a plurality of embosses capable of axially supporting the bottom surface of the bottom body are formed at the bottom of the reservoir tube. A passage communicating between the reservoir chamber and the bottom body lower chamber is formed between the embosses, and a position coaxial with the reservoir tube by radially supporting the bottom body on the inner side of the bottom of the reservoir tube. A plurality of guide projections are formed, and each of the guide projections extends in the axial direction and is formed on the bottom body. Bottom structure of the damper, characterized in that the linear portion abutting a width in the axial direction is formed on the peripheral.