JPH0314589Y2 - - Google Patents

Description

[Detailed Description of the Invention] Industrial Application Field The present invention is installed and fixed to the piston rod of a hydraulic shock absorber disposed between the vehicle body and the axle of an automobile to limit the extension of the hydraulic shock absorber. This invention relates to a support structure for a rebound stopper.

BACKGROUND ART Hydraulic shock absorbers have conventionally been installed between the body and axle of automobiles in order to improve ride comfort or running stability of automobiles. An example will be explained. In the figure, 1 is the outer cylinder, 2
are cylinders, each of which is filled with hydraulic fluid, and a reservoir chamber 3 is provided between them. A piston rod 4 extends through a rod guide 5 provided at one end of the cylinder 2 so as to be insertable and removable.

A piston 6 is permanently fixed to the piston rod 4, and divides the inside of the cylinder 2 into an upper liquid chamber 7 and a lower liquid chamber 8. 9 is a bottom valve that allows limited flow of hydraulic fluid between the inside of the cylinder 2 and the reservoir chamber 3.

On the other hand, a substantially annular fixed seat 10 is fixed to the piston rod 4 at a position above the piston 6, and an annular rebound stopper 11 fitted to the piston rod 4 is fixed to the fixed seat 10. It is placed there. The rebound stopper 11 is generally made of rubber or a synthetic resin material such as permeable polyurethane.

According to such a hydraulic shock absorber, vibrations caused by unevenness of the road surface can be damped by the hydraulic shock absorbing effect of the hydraulic fluid caused by the sliding movement between the piston 6 and the cylinder 2. During such an operation, the rebound stopper 11 placed on the fixed seat 10 comes into contact with the lower end surface of the rod guide 5 during the extension operation of the piston rod 4, and
It has the function of a buffer material that limits the expansion of the material and softens the impact upon contact.

Problems to be Solved by the Invention However, in such a conventional hydraulic shock absorber, as shown in FIG. 3, the outer diameter of the fixed seat 10 and the outer diameter of the rebound stopper 11 are approximately Since they are the same, when the rebound stopper 11 made of rubber or polyurethane swells in the hydraulic fluid over time, the outer diameter of the rebound stopper 11 becomes larger than the outer diameter of the fixed seat 10.

Moreover, a gap is created between the inner circumference of the swollen rebound stopper 11 and the outer circumference of the piston rod 4,
Rebound stopper 1 by easily deflecting in the radial direction
1 largely protrudes from the fixed sheet 10.

When the piston rod 4 is extended in this state, a pressing force acts on the protruding portion from above, and it is strongly pressed against the outer peripheral end 10a of the fixed seat 10, so that the outer peripheral end 10a is formed at a substantially right angle. Therefore, there was a problem that cracks were generated in the rebound stopper 11.

Therefore, the present invention solves the problems with the support structure of the rebound stopper used in conventional hydraulic shock absorbers, prevents the occurrence of cracks in the rebound stopper, and extends the life of the rebound stopper. This provides a support structure that can be used.

Means for Solving the Problems A removable piston rod that extends through a rod guide provided at one end of a cylinder filled with hydraulic fluid, a substantially annular fixed seat fixed at any position on the piston rod, and A hydraulic shock absorber includes a rebound stopper that is placed on a fixed seat and that comes into contact with the rod guide when the piston rod is extended to limit the extension of the piston rod, wherein the fixed seat is supported and fixed by the rebound stopper. The piston rod consists of an annular flange portion and a cylindrical boss portion that projects vertically from the inner edge of the flange portion, and while the boss portion is fixed to the outer wall surface of the piston rod, The end portion is bent in a direction opposite to that of the rebound stopper, and a curved surface is formed at the bent portion to form a rebound stopper support structure for a hydraulic shock absorber.

Function When the rebound stopper immersed in the hydraulic fluid swells over time and a part of it comes into contact with the outer peripheral edge of the fixed seat, a rebound stopper is formed on the outer peripheral edge of the flange that constitutes the fixed seat. Since the rebound stopper comes into contact with the curved surface of the bent portion, no local stress is applied to the rebound stopper.
Deterioration due to damage to the rebound stopper is prevented.

Embodiment An embodiment of the rebound stopper support structure for a hydraulic shock absorber according to the present invention will be described below with reference to the drawings. That is, FIG. 1 shows a substantially annular fixed seat 20 fixed to a position above a piston (not shown) of the piston rod 4 and a rebound stopper 11 mounted on the fixed seat 20. The assembly structure of the piston rod 4 and the cylinder 2, which are provided with the fixed seat 20 and the rebound stopper 11, is the same as the conventional one shown in FIG. 2, so that the explanation will not be repeated. The fixing sheet 20 is made of an annular thin metal plate as a base material, and is formed by drawing the base material to form an annular flange portion 20b on which the rebound stopper 11 is placed, and a circular flange portion 20b on which the rebound stopper 11 is placed. A cylindrical boss part 20c can be formed that projects vertically from the inner edge of the piston rod 4, and the boss part 20c can be fixed to the outer wall surface of the piston rod 4, while the flange part 2
The outer peripheral end 20a of 0b is connected to the rebound stopper 11
Bend it in the opposite direction, and add a curved surface 20 to this bent part.
d is formed.

Therefore, the fixing sheet 20 does not require any complicated steps and can be manufactured very easily.

As a means for fixing the boss portion 20c to the outer wall surface of the piston rod 4, spot welding means can be used.

According to this configuration, the rebound stopper 11
swells in the hydraulic fluid over time and the rebound stopper 11 protrudes from the fixed seat 20,
Even if the piston rod 4 is extended and the rebound stopper 11 is pressed against the outer peripheral end 20a of the fixed seat 20, the curved surface 20 formed on the rebound stopper 11 and the outer peripheral end 20a of the fixed seat 20
d is in curved contact with the rebound stopper 11, and no locally concentrated stress is applied to the rebound stopper 11. Therefore, cracks are prevented from forming within the rebound stopper 11, and damage and deterioration of the rebound stopper 11 can be prevented.

Effects of the Invention As explained in detail above, according to the present invention, the outer peripheral edge of the fixed sheet on which the rebound stopper is placed is bent in the opposite direction to the rebound stopper, and a curved surface is formed on this bent part. Therefore, even if the rebound stopper swells in the hydraulic fluid over time and is pressed against the outer peripheral edge of the fixed seat, the rebound stopper does not press against the outer peripheral edge of the fixed seat. This makes it possible to bring the rebound stopper into curved contact with the rebound stopper, thereby preventing damage to the rebound stopper. In other words, by creating the curved surface contact state, concentrated stress does not act on the rebound stopper, making it possible to prevent the occurrence of cracks, extending the life of the rebound stopper, and improving the performance of the hydraulic shock absorber. Further, since a thin metal plate can be used as the base material of the fixing sheet, and the base material can be bent in the same direction during production to form the boss portion and the curved surface, The effect is that manufacturing is easy.

[Brief explanation of drawings]

Fig. 1 is a sectional view of a main part showing the rebound stopper support structure of a hydraulic shock absorber according to the present invention, Fig. 2 is a partial sectional view showing the structure of a conventional hydraulic shock absorber, and Fig. 3 is a partial sectional view showing the structure of a conventional hydraulic shock absorber. FIG. 3 is an enlarged cross-sectional view of the rebound stopper portion of FIG. 2...Cylinder, 4...Piston rod, 5...
... Rod guide, 11 ... Rebound stopper,
20...Fixed sheet, 20a...Outer peripheral end, 20
b...flange part, 20c...boss part, 20d...
…curved surface.

Claims (1)

[Claims for Utility Model Registration] A removable piston rod that extends through a rod guide provided at one end of a cylinder filled with hydraulic fluid, a fixed seat fixed at any position on the piston rod, and a fixed seat mounted on the fixed seat. A hydraulic shock absorber is provided with a rebound stopper which is placed on the piston rod and limits the extension of the piston rod by coming into contact with the rod guide when the piston rod is extended, wherein the fixed seat has a circular ring shape on which the rebound stopper is placed. It consists of a flange part and a cylindrical boss part that projects vertically from the inner edge of the flange part, and the boss part is fixed to the outer wall surface of the piston rod while the outer peripheral end of the flange part is rebound. A rebound stopper support structure for a hydraulic shock absorber, characterized in that the rebound stopper is bent in the opposite direction to the stopper, and a curved surface is formed at the bent portion.