JPH0893824A - Bottom piece for hydraulic shock absorber - Google Patents

Abstract

PURPOSE: To provide a bottom piece which can be easily machined by press molding, by press molding an intermediate molding body composing a framed cylinder from a flat plate, and stamping out both of an overhand part for positioning and a projecting part for a leg part in one process so as to form the frame part of the intermediate molding body. CONSTITUTION: The bottom part 1a of a hydraulic shock absorber supports the end part of a damper cylinder 2 fitted to and inserted in an outer tube 1 by a bottom piece 3. This bottom piece 3 is vertically movably provided with a check valve 5 on which a valve guide 4 is fitted on its upper side, and which composes a damping valve in this valve guide 4. A part of the frame part of the intermediate molding body composing a framed cylinder press molded from a flat plate, is downwardly bent so that the leg part 8 of the bottom piece 3 is formed, and also the frame part of the intermediate molding body is made to remain so as to be formed as a positioning hung part 7. Further, the upper end of the cylinder part 6 of the bottom piece 3 is formed as the valve seat of the check valve 5.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a bottom piece for a hydraulic shock absorber, and in particular, it is possible to secure a positioning function, improve material yield, and ensure simple processing by press molding. The present invention relates to a method for manufacturing a bottom piece for a hydraulic shock absorber.

[0002]

2. Description of the Related Art As a method for manufacturing a bottom piece for a hydraulic shock absorber that supports a damper cylinder on a bottom portion of an outer tube, a hat type molded body having a flanged cylinder is formed by press molding from a flat plate, and the hat type molded body is manufactured. There is known a method of bending a part of the portion to the side opposite to the cylindrical portion to form a leg portion (Japanese Patent Publication No. 58-8927).
By this manufacturing method, it is possible to form a bottom piece with a flow path between the leg portions by a simple press working without using sintering molding, while closing the end portion of the outer tube with a separate lid member, By positioning the damper cylinder with the lid member, the damper cylinder internal type hydraulic shock absorber can be configured.

On the other hand, as shown in the sectional view of the bottom structure of the conventional thin outer tube of FIG. 7 (a), the damper cylinder 52 is attached to the bottom portion 51a integral with the thin outer tube 51 without using the lid member. When the valve is internally provided, a positioning protrusion 53a is formed on the valve guide 53 that can be easily formed by press working.
By configuring the bottom valve 54 using the valve guide 53, the damper cylinder 52 can be positioned, and the oil chamber S on the damper cylinder 52 side can be positioned.
A flow path is secured between 1 and the annular oil reservoir S2 on the outside thereof by the gap S of the leg portion 58a of the bottom piece 58 supporting the damper cylinder 52.

[0004]

However, as shown in the bottom view of the valve guide of FIG. 2B, the overhanging portion 53 for positioning forming the peripheral portion of the valve guide 53 is formed.
A deteriorates the yield in the material removal of the valve guide 53 that can be easily molded by press working, and disadvantages in terms of material cost cannot be avoided, and improvement thereof is desired.

[0005]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention press-molds an intermediate compact which is a flanged cylinder from a flat plate, and a part of the flange of this intermediate compact is opposite to the cylindrical part. In a bottom piece that has a leg portion that is bent to the side and that supports the damper cylinder to the bottom portion of the outer tube via this leg portion, the flange portion of the intermediate molded body is a protruding portion for positioning in the radial direction of the outer tube. And a protrusion for the leg. It is preferable that an abutting portion bent along the bottom portion of the outer tube is formed at the tip of the leg portion, the flat plate is square, and its corner portion is preferably a protruding portion for the leg portion. Further, it is preferable that the tip end of the protrusion for the leg is used as the projecting portion for positioning.

[0006]

The flange portion of the intermediate molded body is formed by punching out the protruding portion for positioning and the protruding portion for the leg together in one step. Therefore, the protruding portion for positioning has a special material removal and It is formed in the step of forming the leg portion by using the peripheral member pieces of the leg member without any processing, and the protruding portion for positioning thereof prevents the damper cylinder from moving in the radial direction of the outer tube.

When the tips of the legs are used as the contact portions, a stable contact is secured along the bottom portion of the outer tube,
When the bottom part of the outer tube has a conical surface, it functions as a damper cylinder positioning function, and when the corners of a square flat plate are used as the legs, it is possible to increase the yield of material removal. In the case of forming the positioning portion, the leg portion and the positioning portion are formed without the need to specify the bending processing position on the periphery of the collar portion, and the processing load and weight can be reduced.

[0008]

Embodiments of the present invention will be described below with reference to the accompanying drawings. 1 is a sectional view showing a bottom structure of a hydraulic shock absorber according to a first embodiment of the present invention, and FIG. 2 is a bottom view of a bottom piece of the hydraulic shock absorber.

The bottom portion of the hydraulic shock absorber is provided with a damper cylinder 2 in the outer tube 1, and the end portion of the damper cylinder 2 is supported by the bottom piece 3. The bottom piece 3 is fitted with a valve guide 4 on the upper side thereof, and a check valve 5 is provided in the valve guide 4 so as to be movable up and down to form a damping valve.

The bottom piece 3 has a cylindrical seat 6 whose upper end serves as a valve seat of the check valve 5 and which is divided into the lower end of the cylindrical part 6 to project a radial projection 7 for positioning.
Is provided, and the lower side of the overhanging portion 7 is an arcuate leg portion 8 having a gap S, which is in contact with the bottom portion 1a of the outer tube 1 at the lower surface of the contact portion 9 at the lower end thereof, and the gap S is a damper. The oil chamber S1 inside the cylinder 2 and the annular oil reservoir chamber S2 on the outside thereof communicate with each other.

A method of manufacturing the bottom piece will be described. The bottom piece 3 is obtained by punching out a material from a plate material into a substantially disc-shaped shape in which the overhanging portion 7 and the leg portion 8 are expanded, punching out a circular hole at the top of a press-molded hat-shaped molded product, and forming the peripheral edge into a taper. As an intermediate molded body forming a flanged cylinder, or by punching a protrusion of both the overhanging portion 7 and the leg portion 8 on the flange portion of the intermediate molded body forming a cylindrical body with a collar pressed from a circular plate material, the leg portion 8 And the contact portion 9 on the tip side thereof are formed by bending. This contact part 9
The lower surface of is set to an inclination angle along the bottom portion 1a of the outer tube 1.

Since the flange portion of the intermediate molded body is formed by punching out the positioning overhanging portion 7 and the leg protruding portion 8 in one step, the positioning overhanging portion 7 is special. Legs 8 without the need for special material removal and processing
It is formed in the step of bending the leg portion by the member piece corresponding to the gap S between the.

The positioning overhanging portion 7 thus formed prevents the damper cylinder 2 from moving in the radial direction of the outer tube 1, and the abutting portion 9 at the tip of the leg portion 8 of the outer tube 1 extends. Since the damper cylinder 2 is stably abutted along the bottom portion 1a, a stable arrangement of the damper cylinder 2 is ensured, and when the bottom portion 1a has a conical surface, the damper cylinder 2 is positioned. Therefore, the bottom piece for a hydraulic shock absorber according to the present invention, while ensuring the positioning function, while improving the material yield,
It is possible to secure simple processing by press molding.

3 and 4 are a sectional view of the bottom piece according to the second embodiment and a working procedure thereof. This bottom piece 13 is provided with a large contact portion 19 at the tip of the leg portion 18 by taking the material thereof, and the manufacturing procedure is as follows.
A bulging portion 17 for positioning is arranged on each side portion of the square plate material, and each corner portion of the plate material is punched out into a shape to be a projection for the leg portion 18, and this square plate is press-molded to form a flanged cylinder. As a molded body (A), a circular hole 16a is punched out at the top of the cylindrical portion 16 (B), and the peripheral edge of the circular hole 16a is molded into a taper 16b (C). As shown in the bottom view of FIG. 3C, the flange of the intermediate molded body has a protruding portion 17 and a leg portion 18 for positioning in the radial direction of the outer tube.
The leg part 1
The protrusions for 8 are bent downward (D) and (d), and the ends thereof are bent inward to form contact portions 19 (E) and (e).

In the bottom piece 13, the corners of a square flat plate are used as the legs 18 to enable high-yield material removal, and the abutting portions 19 at the tips of the legs 18 are along the bottom portion of the outer tube. And a stable contact is ensured, and when the bottom portion of the outer tube has a conical surface, the damper cylinder is positioned.

5 and 6 are a sectional view of the bottom piece according to the third embodiment and a working procedure thereof. In this bottom piece 23, the legs 28 also serve as positioning.
The manufacturing procedure is such that each corner of a square plate material is punched out as a protrusion for a leg portion 28 having a shape that also serves as an overhanging portion 27 for positioning, and this square plate is formed into a cylinder with a collar by press molding ( A), a circular hole 26a is punched out at the top of the cylindrical portion 26 (B), and the peripheral edge of the circular hole 26a is formed into a taper 26b (C). As shown in the bottom view of FIG. 2C, the flange of this intermediate molded body has a shape in which a protruding portion for a leg portion 28 that also serves as a protruding portion 27 for positioning is punched out. Bend the protrusion downward (D),
(D) Further, the end portion is bent outward to form the contact portion 29 (E), (e), and the outer peripheral side thereof is used as the overhanging portion 27 for positioning.

In the above bottom piece, the leg portion 28 also serves as the overhanging portion 27 for positioning, and the leg portion 28 also for positioning can be formed without the need to specify the bending processing position on the periphery of the collar portion. Can be reduced.

[0018]

According to the present invention as described above,
Press-molding an intermediate molded body forming a flanged cylinder from a flat plate,
Since the flange portion of the intermediate molded body is formed by punching out the positioning protrusion and the leg protrusion in a single process, the positioning protrusion requires special material removal and processing. Without being formed in the bending process of the leg portion by the peripheral member pieces of the leg portion member, and the overhanging portion for positioning serves to prevent the damper cylinder from moving in the radial direction of the outer tube. Therefore, the bottom piece for a hydraulic shock absorber according to the present invention can secure a positioning function and, at the same time, can improve the material yield and ensure a simple processing by press molding, thereby simplifying the bottom structure of the hydraulic shock absorber. Can be achieved.

In addition, a stable contact is secured along the bottom portion of the outer tube when the tips of the legs are used as the contact portion, and a damper is used when the bottom portion of the outer tube has a conical surface. Positions the cylinder,
When the corners of a square flat plate are used as legs, it is possible to achieve a high material yield, and when the tips of the legs are positioning parts, it is necessary to specify the bending position of the flange periphery. Instead, the leg portion and the positioning portion are formed, and the processing load and the weight can be reduced.

[Brief description of drawings]

FIG. 1 is a sectional view showing a bottom structure of a hydraulic shock absorber according to a first embodiment of the present invention.

FIG. 2 is a bottom view of a bottom piece of the hydraulic shock absorber.

FIG. 3 is an assembled sectional view of a bottom piece according to a second embodiment.

[Figure 4] Processing procedure diagram of the bottom piece

FIG. 5 is an assembled sectional view of a bottom piece according to the third embodiment.

[Fig. 6] Processing procedure diagram of the bottom piece

7A is a cross-sectional view of a bottom structure using a conventional thin outer tube, and FIG. 7B is a bottom view of a valve guide.

[Explanation of symbols]

1 ... Outer tube, 1a ... Bottom part, 2 ... Damper cylinder, 3, 13, 23 ... Bottom piece, 4 ... Valve guide, 5 ... Check valve, 6, 16, 26 ... Cylindrical part, 7, 17, 27 ... Overhang Part, 8, 18, 28 ... Leg part, 9, 19, 29 ... Contact part, S ... Gap, S1 ... Oil chamber,
S2 ... Annular oil reservoir.

Claims (4)

[Claims] 1. An intermediate molded body having a flanged cylinder is press-molded from a flat plate, and a leg portion is formed by bending a part of the collar portion of the intermediate molded body to the side opposite to the cylindrical portion. In the bottom piece that supports the damper cylinder to the bottom portion of the outer tube via the flange portion of the intermediate molded body, the flange portion includes an overhanging portion for positioning in the radial direction of the outer tube and a protruding portion for the leg portion. Bottom piece for hydraulic shock absorber. 2. The bottom piece for a hydraulic shock absorber according to claim 1, wherein an abutting portion bent along the bottom portion of the outer tube is formed at a tip of the leg portion. Bottom piece. 3. The bottom piece for a hydraulic shock absorber according to claim 2, wherein the flat plate has a square shape, and a corner portion thereof is a protrusion for the leg portion. 4. The bottom piece for a hydraulic shock absorber according to claim 3, wherein a tip of the protrusion for the leg portion is a projecting portion for the positioning.