JPH0893825A - Bottom structure of vehicular shock absorber and its forming method - Google Patents

Abstract

PURPOSE: To provide the bottom structure of a lightweight vehicular shock absorber and its forming method which can be easily machined and can retain its rigidity. CONSTITUTION: One end part 1a of an outer tube 1 consisting of a thin aluminum straight pipe is closed by a spinning process, the outer circumferential side of the bottom part of the outer tube 1 is formed as a fitting part 2 by a swaging process and two wide diameter parts 3, 4 are bulge-processed to the vicinity of the fitting part 2 so that a clamping cylinder mechanism 5 is inwardly arranged. A collar 6 is inscribed on the inner circumferential side of the fitting part 2, a circumferential groove 7 is formed on the outer circumferential side thereof, and the cross sectional shape of the circumferential groove 7 is formed to match to the press molding of the lateral groove 8 of the fitting part 2. An interval between the outer circumference of the damping cylinder mechanism 5 and the outer tube 1 is formed as an oil storage chamber 9, and a spring seat 10 and a brake hose bracket 11 are fixed on the outer circumference of the outer tube 1.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a bottom structure for a vehicle shock absorber and a method for forming the same, and more particularly to a lightweight bottom structure for a vehicle shock absorber which is easy to process and ensures rigidity, and the formation thereof. Regarding the method.

[0002]

2. Description of the Related Art There is known a vehicle shock absorber in which a damping cylinder mechanism is arranged in an outer tube and fixed to a knuckle member that supports wheels. The bottom part of the outer tube of this shock absorber requires rigidity to counter the side force from the knuckle part, and when it is fitted into the knuckle part and fixed by tightening, the fluctuation of the outer tube length due to the tightening force is required. Occurs, which affects the sealing life of the rod guide, etc., so sufficient rigidity is required, while thickening only the necessary parts to reduce the weight of the shock absorber, or
Since it has to be formed in a large diameter, the cost increase of the outer tube cannot be avoided.

In order to solve this problem, a technique of constructing an outer tube by a straight pipe member having a constant wall thickness has been proposed. For example, in the sectional view of the conventional bottom structure of a vehicle shock absorber shown in FIG. As shown, the damping cylinder mechanism 10
The outer tube 102 in which 1 is provided is formed of a thin straight pipe material having a constant wall thickness, and a knuckle bracket 103 is fitted to the outer peripheral side at the end portion thereof, and a bottomed cylindrical member 104 also serving as a reinforcement on the inner peripheral side. Insert and weld these 1
A technique of fixing by means of No. 05 (Japanese Utility Model Laid-Open No. 4-96637) has been proposed to reduce the cost of the outer tube member, reduce the overall weight, and secure the rigidity of the knuckle attachment portion.

[0004]

However, in the above technique, a thin straight pipe material having a constant wall thickness over the entire length is used, the outer tube is simply constructed by plastic working such as caulking on the open end side, and the outer tube is partially formed. While it is possible to reduce the cost by avoiding forging or cutting when forming a thick wall or forming a large diameter, it becomes necessary to weld the end part, and by mixing with plastic working, the outer tube The processing steps become complicated, and the advantage of cost reduction of the outer tube having a simple structure is lost.

[0005]

In order to solve the above-mentioned problems, the present invention forms a fitting portion on the outer peripheral surface of the end portion of an outer tube in which a damping cylinder mechanism is provided by a drawing process such as swaging and the like. In the vehicle shock absorber, a lateral groove for press-fitting a positioning pin to be inserted in the tangential direction is press-formed in the joint portion, and the joint portion is fitted into the knuckle side for tightening and fixing the joint portion. A collar having rigidity capable of withstanding a load received from the knuckle side is inscribed in the fitting portion, and the outer peripheral surface of the collar is provided with a convex portion to be formed on the inner circumferential side of the lateral groove of the fitting portion. A possible circumferential groove was formed.

[0006]

[Function] Since the collar having the rigidity capable of resisting the load received from the knuckle side is inscribed in the fitting portion of the outer tube, the fitting portion of the outer tube formed of a thin member ensures sufficient rigidity, and The fitting portion is formed by the drawing process such as swaging and the like without any trouble together with the fixing of the collar, and the lateral groove of the fitting portion which faces the circumferential groove of the collar is formed by press molding without requiring a large load. Furthermore, by applying spinning processing on the closed end side of the outer tube and caulking processing on the open end side, the entire outer tube processing process can be easily formed by plastic working of thin-walled members, ensuring lightweight and sufficient rigidity. A possible vehicle shock absorber can be configured by simple processing.

[0007]

Embodiments of the present invention will be described below with reference to the accompanying drawings. FIG. 1 is a partial sectional view showing a bottom structure of a vehicle shock absorber according to an embodiment of the present invention.

The outer tube 1 of the shock absorber closes one end 1a of a pipe raw pipe which is a thin aluminum straight pipe, and the outer peripheral side of this bottom portion is a fitting portion 2 for fitting into a knuckle portion (not shown). In the vicinity of the fitting part 2, the two expanded parts 3,
4 is formed, and the damping cylinder mechanism 5 is internally provided.

A collar 6 having a rigidity capable of withstanding a load received from the knuckle side is inscribed on the inner peripheral side of the fitting portion 2. A peripheral groove 7 is formed on the outer peripheral surface of the collar 6, and the peripheral groove 7 corresponds to the press molding of the lateral groove 8 extending in the tangential direction of the fitting portion 2, and the convex portion to be formed on the inner peripheral side thereof. It has a cross-sectional shape that can accept The lateral groove 8 forms a concave portion into which a positioning pin (not shown) inserted when the fitting portion 2 is fitted into the knuckle side is fitted.

On the inner peripheral side of the fitting portion 2, a damping cylinder mechanism 5 is attached to the end portion 1a in contact with the end portion 1a, or to the upper end of the collar 6 as shown in the drawing, and the outer tube 1 on the outer periphery thereof.
The oil reservoir chamber 9 is provided between the spring seat 10 and the brake hose bracket 11, and the spring seat 10 and the brake hose bracket 11 are fixed by engaging the enlarged diameter portions 3 and 4. This brake hose bracket 1
The lower part of 1 is provided with a convex portion 11a which is fitted to the knuckle side and defines the angular position thereof.

The operation of the bottom structure of the vehicle shock absorber having the above structure will be described. In the vehicle shock absorber, a thin straight aluminum tube is cut into a required length to form an outer tube 1, and one end 1a thereof is closed by spinning.
The two enlarged diameter portions 3 and 4 are formed by bulging, the collar 6 is inserted, and the fitting portion 2 at the bottom portion is formed by swaging. At that time, the collar 6 is fixed. Then, the lateral groove 8 is pressed, the damping cylinder mechanism 5 is internally provided, and the open end portion (not shown) is formed by caulking to form a shock absorber, and the outer tube 1 is a lightweight thin-wall straight pipe material. It can be easily formed by plastic working.

In this case, the fitting portion 2 of the outer tube 1
Since the collar 6 inscribed in has a rigidity that can withstand the load received from the knuckle side, the outer tube 1 does not need rigidity, so a low-cost aluminum and other thin-walled straight pipe that can be made lightweight can be used. Can be applied.

The fitting portion 2 has a large rigidity secured by the collar 6, and is formed without trouble by drawing such as swaging, and the lateral groove of the fitting portion faces the circumferential groove of the collar. The fixing of the collar is supplemented at the same time as the work is carried out by the light load press molding without requiring a great working load.

As described above, the bottom structure has sufficient rigidity even when the outer tube is formed of a light and thin straight pipe material, including the spinning process on the closed end side of the outer tube and the caulking process on the open end side. In addition to being secured, the outer tube can be easily formed by only plastic working of a thin member having a light load without requiring other working steps such as cutting and welding.

[0015]

According to the present invention as described above,
Since the collar, which has the rigidity to withstand the load received from the knuckle side, is inscribed in the fitting part of the outer tube, the fitting part of the outer tube made of thin-walled member has sufficient rigidity and swaging etc. The fitting part is formed by the drawing process of the collar without any trouble as well as the fixation of the collar, and the lateral groove of the fitting part facing the circumferential groove of the collar is
It is processed by press molding without requiring a large load. Furthermore, by applying spinning processing on the closed end side of the outer tube or caulking processing on the open end side,
All outer tube processing steps are easily formed by plastic processing of thin-walled members without the need for other processing steps such as cutting or welding, making it easy to manufacture a vehicle shock absorber that is lightweight and has sufficient rigidity. Can be configured by.

[Brief description of drawings]

FIG. 1 is a partial sectional view of a bottom structure of a vehicle shock absorber according to an embodiment of the present invention.

FIG. 2 is a partial cross-sectional view of a conventional bottom structure of a vehicle shock absorber.

[Explanation of symbols]

1 ... Outer tube, 1a ... One end part, 2 ... Fitting part,
3, 4 ... expanded diameter part, 5 ... damping cylinder mechanism, 6 ... collar,
7 ... Circular groove, 8 ... Lateral groove, 9 ... Oil reservoir, 10 ... Spring seat, 11 ... Brake hose bracket, 11a ... Convex part.

Claims (2)

[Claims] 1. A fitting portion is formed on an outer peripheral surface of an end portion of an outer tube having a damping cylinder mechanism therein by drawing such as swaging, and a positioning pin inserted in the fitting portion in a tangential direction thereof. In a vehicle shock absorber in which a lateral groove that fits is press-formed and is fitted into the knuckle side that tightens and fixes the fitting part, the fitting part of the outer tube can withstand the load received from the knuckle side. For a vehicle, in which a collar having a high rigidity is inscribed, and an outer circumferential surface of the collar is formed with a circumferential groove capable of receiving a convex portion to be formed on the inner circumferential side of the lateral groove of the fitting portion. Bottom structure of shock absorber. 2. A step of closing one end of a pipe member forming an outer tube having a damping cylinder mechanism therein by a spinning process, and a step of forming a fitting part on the outer peripheral surface of the end part by a drawing process such as swaging. In the method of forming the bottom portion of the vehicle shock absorber for fitting and tightening on the knuckle side, the pipe member is constituted by a straight pipe member having a constant wall thickness over the entire length,
A vehicle shock absorber characterized in that a collar having rigidity capable of withstanding a load received from the knuckle side is inserted into the fitting portion position, and the collar is fixed in the step of forming the fitting portion. For forming the bottom part of a container.