JP2002070923A - Shock absorber assembly method and bump stopper cap structure - Google Patents

Abstract

PROBLEM TO BE SOLVED: To protect a piston rod from a flaw and improve the crimping workability of a damper tube when an open end of the damper tube is crimped and then a bump stopper cap is fixed to the crimped open end of the damper tube in a shock absorber. SOLUTION: A shock absorber 10 is so assembled that after an open end of an outer tube 21 is crimped, bump stopper caps 31 and 32 are fixed to the open end of the outer tube 21.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a method for assembling a shock absorber and a bump stopper cap structure.

[0002]

2. Description of the Related Art Conventionally, as disclosed in Japanese Utility Model Application Laid-Open No. 62-202543, a piston having a mounting portion such as an eye joint fixed to an outer end of a piston rod having a piston and a bump rubber provided as a shock absorber. A rod assembly is inserted, a piston of the piston rod assembly is inserted into a damper tube, an outer end side of the piston rod assembly is projected from an open end of the damper tube, and an open end of the damper tube is crimped, There is one in which a bump stopper cap is fixed to an open end of a damper tube.

[0003] In a conventional method of assembling a shock absorber, a bump stopper cap is previously assembled around a piston rod in a sub-assembly stage of a piston rod assembly. Then, the piston rod is assembled to the damper tube, and the opening end of the damper tube is swaged by roll swaging or the like, and then the above-described bump stopper cap is press-fitted and fixed to the swaged opening end of the damper tube.

In the prior art, when the opening end of the damper tube is swaged, the bump stopper cap is mounted on the piston rod so that the bump stopper cap installed around the piston rod does not hinder the swaging operation. The tube is held by a bump stopper cap fixing means at a position away from the open end of the tube.

[0005]

SUMMARY OF THE INVENTION A bump stopper cap fixing means for holding the bump stopper cap so that the bump stopper cap does not drop when assembled to a piston rod so as not to hinder the opening end of the damper tube. is necessary.

When the bump stopper cap is attached to the piston rod, a sufficient space for caulking work cannot be secured around the opening end of the damper tube, and the caulking work is difficult.

[0007] Since the bump stopper cap is previously attached to the piston rod, the piston rod may be scratched, which may adversely affect the slidability of the piston rod.

SUMMARY OF THE INVENTION An object of the present invention is to provide a shock absorber, in which, after an opening end of a damper tube is swaged, a bump stopper cap is fixed to the swaged opening end of the damper tube without damaging a piston rod. ,
Another object is to improve the workability of caulking the damper tube.

[0009]

According to a first aspect of the present invention, there is provided a piston rod assembly having an eye joint fixed to an outer end of a piston rod having a piston and a bump rubber provided thereon. A shock absorber in which a piston is inserted into a damper tube, an outer end side of the piston rod assembly protrudes from an open end of the damper tube, and an open end of the damper tube is swaged. This is a method for assembling a shock absorber in which a bump stopper cap is assembled after being swaged and fixed to an open end of the damper tube.

According to a second aspect of the present invention, there is provided a piston rod assembly in which an eye joint is fixed to an outer end of a piston rod having a piston and a bump rubber is provided, and the piston of the piston rod assembly is placed in a damper tube. A shock absorber that is inserted, projects the outer end side of the piston rod assembly from the open end of the damper tube, and crimps the open end of the damper tube.
A bump stopper cap structure of a shock absorber in which a bump stopper cap composed of a plurality of members is fixed to an open end of the damper tube, and a bump rubber contact surface of the bump stopper cap is made flat.

According to a third aspect of the present invention, in the second aspect of the present invention, the bump stopper cap is a bump stopper cap assembly including a first bump stopper cap and a second bump stopper cap. The cap has a U-shaped notch formed in the end plate fitted around the piston rod, and an open portion formed in the side plate extending at a right angle from the end plate so as to extend at a right angle from the U-shaped notch. The second bump stopper cap is provided with a U-shaped notch fitted around the piston rod on the end plate and a convex portion fitted into the notch of the first bump stopper cap, and a right angle from the end plate. An opening is formed on the side plate extending to extend from the U-shaped notch at a right angle,
A bump of a shock absorber fixed to an open end of the damper tube in a state in which both bump stopper caps are overlapped and coupled so that a convex portion of the second bump stopper cap is fitted into a cutout portion of the first bump stopper cap. It is a stopper cap structure.

According to a fourth aspect of the present invention, in the second aspect of the present invention, the bump stopper cap is a bump stopper cap assembly including a first bump stopper cap and a second bump stopper cap. The cap has a U-shaped notch formed in the end plate which fits around the piston rod, and has a radially enlarged portion extending at a right angle from a circumferential half of the end plate and a radially reduced portion following the radially enlarged portion. A side plate provided with a portion, an open portion extending at a right angle from the U-shaped cutout portion is provided in the side plate, and the second bump stopper cap is fitted on an end plate around the piston rod. A convex portion corresponding to the notch portion and the notch portion of the first bump stopper cap, a side plate extending at a right angle from a circumferential half of the end plate is provided, and the diameter of the first bump stopper cap is increased. The outer edge of the end plate of the second bump stopper cap is inserted into the groove provided on the inner periphery of the first bump stopper cap, and the first bump stopper cap and the second bump stopper cap are connected to each other. The two bump stopper caps are overlapped and connected so as to fit the projections of the second bump stopper cap, and the protrusions or holes formed on the end plate of the first bump stopper cap and the end plate of the second bump stopper cap And a bump stopper cap structure of a shock absorber fixed to an opening end of the damper tube in a state of being engaged with a hole or a projection formed in the damper tube.

According to a fifth aspect of the present invention, in the second aspect, the bump stopper cap is a bump stopper cap assembly including a first bump stopper cap and a second bump stopper cap, and the first bump stopper is provided. The cap forms a U-shaped notch fitted around the piston rod in a semicircular end plate, and forms a concave portion or a convex portion at both circumferential ends of a side plate extending at a right angle from the end plate. The second bump stopper cap has a semicircular end plate formed with a U-shaped notch fitted around the piston rod, and both end portions in a circumferential direction of a side plate extending at a right angle from the end plate. Forming a projection or a recess engaging with the depression or projection of the first bump stopper cap, and forming the projection or recess of the second bump stopper cap in the recess or projection of the first bump stopper cap. Engaging the parts or recesses is bump stopper cap structure of the first bump stopper cap and shock absorber coupling the second bump stopper cap.

[0014]

According to the first aspect of the invention, there is the following operation (1). (1) Since the bump stopper cap is assembled for the first time after caulking the open end of the damper tube, when caulking the open end of the damper tube, the bump stopper cap has not yet been assembled around the piston rod.
No bump stopper cap fixing means for fixing the bump stopper cap so as not to fall around the piston rod is unnecessary. Further, since a sufficient space for the crimping operation can be secured around the opening end of the damper tube, the crimping operation is easy. Furthermore, the bump stopper cap does not scratch the piston rod, and there is no adverse effect on the slidability of the piston rod.

According to the second aspect of the present invention, there are the following operations (2) and (3). (2) Since the bump stopper cap is composed of a plurality of members, the bump stopper cap can be assembled after caulking the open end of the damper tube.

(3) Since the bump rubber contact surface of the bump stopper cap is flat, the bump rubber is not unevenly worn.

According to the third aspect of the invention, there are the following operations (4) and (5). (4) After the second bump stopper cap is connected to the first bump stopper cap on the piston rod, it can be press-fitted and fixed to the damper tube.

(5) The U-shaped notch of the first bump stopper cap and the projection of the second bump stopper cap are fitted,
A flat bump rubber contact surface can be formed, and the rotation of both is also prevented.

According to the invention of claim 4, there are the following operations (6) to (8). (6) Since the first bump stopper cap and the second bump stopper cap can be directly fixed to the open end of the damper tube without previously joining the first bump stopper cap and the second bump stopper cap on the piston rod, a step of joining them on the piston rod is required. Can be reduced.

(7) Since the outer edge of the end plate of the second bump stopper cap is slid and inserted into the enlarged diameter portion of the first bump stopper cap to be joined, the two are fixed in the axial direction to prevent them from coming off.

(8) Since the side plates of the first bump stopper cap and the second bump stopper cap are provided only on half of the circumferential direction thereof, the weight and cost can be reduced.

According to the fifth aspect of the invention, there are the following operations (9) and (10). (9) Since the first bump stopper cap and the second bump stopper cap can be directly fixed to the open end of the damper tube without previously connecting the first bump stopper cap and the second bump stopper cap on the piston rod, the step of connecting them on the piston rod is omitted. Can be reduced.

(10) Since the end plates of the first bump stopper cap and the second bump stopper cap are formed in a semicircular shape, and the side plates are provided only on half of the circumferential direction thereof, the weight and cost can be reduced.

[0024]

FIG. 1 is a half sectional view showing a shock absorber according to a first embodiment, FIG. 2 shows a bump stopper cap structure of the shock absorber, and FIG.
(B) is a plan view, FIG. 3 is a schematic diagram showing a first bump stopper cap, FIG. 4 is a schematic diagram showing a second bump stopper cap, and FIG. 5 is a schematic diagram showing a first bump stopper cap of the second embodiment. 6, FIG. 6 is a schematic diagram showing a second bump stopper cap of the second embodiment, FIG. 7 is a schematic diagram showing a first bump stopper cap of the third embodiment, and FIG. 8 is a second bump stopper cap of the third embodiment. FIG.

(First Embodiment) (FIGS. 1 to 4) The assembling structure and assembling procedure of the shock absorber 10 according to the first embodiment are performed by the following (A) to (C).

(A) Sub-assembly of piston rod assembly An eye joint 12 and a dust cover cap 14 are welded and fixed to the outer end of a piston rod 11, and a bump rubber 13, a seal 15, a rod guide 16, a rebound rubber are mounted from the inner end side. 17, rebound seat 18, piston 19,
The piston rod assembly to which the nut 20 is attached is assembled.

(B) Subassembly of damper tube assembly Bottom cap 2 fixed to the lower part of outer tube 21
4A, fix the eye joint 23 to the outer tube 2
A damper tube assembly in which the cylinder 22 to which the bottom piece 24B is press-fitted and fixed is inserted into the inside of the cylinder 1.

(C) Assembly of Shock Absorber 10 The piston rod assembly is inserted into the damper tube assembly, and the open end of the outer tube 21 is swaged to form the swaged portion 25.
After that, the bump stopper cap assembly 30 is assembled, and the shock absorber 10 is formed. At this time, the bump stopper cap assembly 30 is constituted by the first and second bump stopper caps 31 and 32, and the bump stopper cap assembly 30 is fixed to the open end (the caulking portion 25) of the outer tube 21, The bump rubber contact surface 33 of the bump stopper cap assembly 30 is made flat.

However, the specific configuration of the bump stopper cap assembly 30 of (C) is as follows.

The first bump stopper cap 31 has a U-shaped notch 31B formed around the piston rod 11 in the end plate 31A, and a U-shaped notch formed in a side plate 31C extending at a right angle from the end plate 31A. An opening 31D is formed to extend at a right angle from 31B.

The second bump stopper cap 32 is shown in FIG.
As shown in FIG. 5, a U-shaped notch 32B fitted around the piston rod 11 and a convex portion 32C fitted into the notch 31B of the first bump stopper cap 31 are provided on the end plate 32A.
An opening 32E is formed in a side plate 32D extending at a right angle from the end plate 32A so as to extend at a right angle from the U-shaped notch 32B.

The bump stopper cap assembly 30 is mounted on the piston rod 11 with the first bump stopper cap 3
After the second bump stopper cap 32 is overlapped and connected to the inside 1, it is press-fitted and fixed to the outer tube 21.

The notch portions 31B and 32B of both bump stopper caps 31 and 32 are arranged so as not to overlap with each other.
It is sufficient that the projection 32C of the second bump stopper cap 32 fits into the notch 31B of the bump stopper cap 31, and the direction is not specified.

Side plate 3 of first bump stopper cap 31
1C, a projection 31E is provided on the inner surface thereof.
The bump stopper cap 32 engages with the hole 32F of the side plate 32D, and the two are fixed in the axial direction to prevent each other from coming off.

The notch 31B of the first bump stopper cap 31 and the notch 32 of the second bump stopper cap 32
B is formed larger than the outer diameter of the piston rod 11 and does not impair the slidability of the piston rod 11.

According to the present embodiment, the following operations are provided. (1) The bump stopper caps 31 and 32 are not attached to the piston rod 1 until the open end of the outer tube 21 is crimped.
When the outer tube 21 is crimped at the open end to assemble the outer tube 1 around the bump stopper cap 31,
Since the 32 is not assembled around the piston rod 11, no bump stopper cap fixing means for fixing the bump stopper caps 31, 32 so as not to fall around the piston rod 11 is required. Further, since a sufficient space for the crimping operation can be secured around the opening end of the outer tube 21, the crimping operation is easy. Further, the bump stopper caps 31 and 32 do not scratch the piston rod 11, and the slidability of the piston rod 11 is not adversely affected.

(2) Since the bump stopper caps 31 and 32 are composed of a plurality of members, the bump stopper caps 31 and 32 can be assembled after caulking the open end of the outer tube 21.

(3) Since the bump rubber contact surfaces 33 of the bump stopper caps 31 and 32 become flat, the bump rubber 13 does not wear unevenly.

(4) After the second bump stopper cap 32 is connected to the first bump stopper cap 31 on the piston rod 11, the second bump stopper cap 32 can be press-fitted and fixed to the outer tube 21.

(5) U of the first bump stopper cap 31
The notch 31B and the projection 32C of the second bump stopper cap 32 are fitted to each other, so that a flat bump rubber contact surface 33 can be formed.

(Second Embodiment) (FIGS. 5 and 6) The second embodiment differs from the first embodiment in that a bump stopper cap assembly 40 is used instead of the bump stopper cap assembly 30. .

The bump stopper cap assembly 40 includes a first bump stopper cap 41 and a second bump stopper cap 42.

The first bump stopper cap 41 is shown in FIG.
As shown in FIG. 5, a U-shaped notch 41B fitted around the piston rod 11 is formed in the end plate 41A, and extends at a right angle from a circumferential half of the end plate 41A which does not overlap with the notch 41B. Side plate 41E provided with a diameter portion 41C and a reduced diameter portion 41D
The side plate 41E is provided with an opening 41F extending at a right angle from the U-shaped notch 41B. A groove 41G is formed on the inner periphery of the enlarged diameter portion 41C.

The second bump stopper cap 42 has a U-shaped notch 42B fitted around the piston rod 11 on the end plate 42A and a convex portion 42C corresponding to the notch 41B of the first bump stopper cap 41. And a side plate 42D extending at a right angle from a circumferential half of the end plate 42A.

The outer periphery of the end plate 42A of the second bump stopper cap 42 is formed in the groove 41G provided on the inner periphery of the enlarged diameter portion 41C of the first bump stopper cap 41 around the piston rod 11. Then, the first bump stopper cap 41 and the second bump stopper cap 42 are overlapped and connected.

The bump stopper cap assembly 40 includes a first bump stopper cap 41 on the piston rod 11.
The first and second bump stopper caps 42 may be directly fixed to the open end of the outer tube 21 without being connected in advance.

The notch portions 41B and 42B of both the bump stopper caps 41 and 42 are arranged so as not to overlap, and the first
It is sufficient that the protrusion 42C of the second bump stopper cap 42 fits into the notch 41B of the bump stopper cap 41, and the direction is not specified.

End plate 4 of first bump stopper cap 41
The protrusion 41H formed on the inner surface of 1A and the hole 42E formed in the end plate 42A of the second bump stopper cap 42 are engaged, and both are fixed in the circumferential direction to prevent rotation of each other.

The notch 41B of the first bump stopper cap 41 and the notch 42 of the second bump stopper cap 42
B is formed larger than the outer diameter of the piston rod 11 and does not impair the slidability of the piston rod 11.

According to the present embodiment, the following operations are provided. (1) The first bump stopper cap 41 and the second bump stopper cap 42 can be directly fixed to the open end of the outer tube 21 without previously connecting the first bump stopper cap 41 and the second bump stopper cap 42 on the piston rod 11. Can be reduced.

(2) The end plate 4 of the second bump stopper cap 42 is attached to the enlarged diameter portion 41C of the first bump stopper cap 41.
Since the outer edge of the 2A is slid and inserted and connected, both are fixed in the axial direction to prevent the 2A from slipping off.

(3) Since the side plates 41E and 42D of the first bump stopper cap 41 and the second bump stopper cap 42 are provided only on half of the circumferential direction thereof, the weight and cost can be reduced.

Third Embodiment (FIGS. 7 and 8) The third embodiment differs from the first embodiment in that a bump stopper cap assembly 50 is used instead of the bump stopper cap assembly 30. .

The bump stopper cap assembly 50 includes a first bump stopper cap 51 and a second bump stopper cap 52.

The first bump stopper cap 51 is shown in FIG.
As shown in the figure, the piston rod 11 is attached to the semicircular end plate 51A.
A U-shaped notch 51B fitted around the end plate 5 is formed.
A concave portion 51D and a convex portion 51E are formed at both circumferential ends of a side plate 51C extending at a right angle from 1A.

FIG. 8 shows the second bump stopper cap 52.
As shown in the figure, the piston rod 11 is attached to the semicircular end plate 52A.
A U-shaped notch 52B fitted around the end plate 5 is formed.
A convex portion 52D and a concave portion 52E that engage with the concave portion 51D and the convex portion 51E of the first bump stopper cap 51 are provided at both ends in the circumferential direction of the side plate 52C extending at a right angle from 2A.
To form

The bump stopper cap assembly 50 includes a concave portion 51D and a convex portion 51E of the first bump stopper cap 51 and a convex portion 52D and a concave portion 52E of the second bump stopper cap 52, respectively, around the piston rod 11. And the first bump stopper cap 51 and the second bump stopper cap 52 are overlapped and connected.

The bump stopper cap assembly 50 includes a first bump stopper cap 51 on the piston rod 11.
The first and second bump stopper caps 52 may be directly fixed to the open end of the outer tube 21 without being connected in advance.

The bump portions of both bump stopper caps 51 and 52 (concave portion 51D, convex portion 51E, convex portion 52D, concave portion 52)
E) may be engaged in the axial direction and the radial direction, and the shape is not specified.

The notch 51B of the first bump stopper cap 51 and the notch 52 of the second bump stopper cap 52
B is formed to be larger than the outer diameter of the piston rod 11, does not impair the slidability of the piston rod 11, and improves the engagement of the irregularities around the piston rod 11. That is, the first bump stopper cap 51 and the second
The bump stopper cap 52 engages the concave and convex portions (the concave portion 51D and the convex portion 52D, and the convex portion 51E and the concave portion 52E).
At this time, after their central axes (the central axes of the notches 51B and 52B) are shifted laterally and approach each other in their radial directions, they are overlapped in a direction perpendicular to their central axes. , And engage these uneven portions.

According to the present embodiment, the following operations are provided. (1) The first bump stopper cap 51 and the second bump stopper cap 52 can be directly fixed to the open end of the outer tube 21 without previously connecting the first bump stopper cap 51 and the second bump stopper cap 52 on the piston rod 11. Can be reduced.

(2) Since the end plates 51A and 52A of the first bump stopper cap 51 and the second bump stopper cap 52 are formed in a semicircular shape, and the side plates 51C and 52C are provided only on their half circumference in the circumferential direction. Weight and cost can be reduced.

The embodiment of the present invention has been described in detail with reference to the drawings. However, the specific configuration of the present invention is not limited to this embodiment, and the design can be changed without departing from the scope of the present invention. The present invention is also included in the present invention. For example, the present invention is not limited to a double-tube structure in which the damper tube includes the outer tube and the cylinder, but may be applied to a single-tube structure in which the damper tube includes only the cylinder.

[0064]

As described above, according to the present invention, in the shock absorber, after the opening end of the damper tube is swaged, the bump stopper cap is fixed to the swaged opening end of the damper tube. It is possible to improve the workability of caulking the damper tube without scratching the rod.

[Brief description of the drawings]

FIG. 1 is a half sectional view showing a shock absorber of a first embodiment.

FIG. 2 shows a bump stopper cap structure of a shock absorber, wherein (A) is a front view and (B) is a plan view.

FIG. 3 is a schematic view showing a first bump stopper cap.

FIG. 4 is a schematic view showing a second bump stopper cap.

FIG. 5 is a schematic view showing a first bump stopper cap of a second embodiment.

FIG. 6 is a schematic view showing a second bump stopper cap of the second embodiment.

FIG. 7 is a schematic view showing a first bump stopper cap of a third embodiment.

FIG. 8 is a schematic view showing a second bump stopper cap of the third embodiment.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Shock absorber 11 Piston rod 12 Eye joint 13 Bump rubber 21 Outer tube 22 Cylinder 25 Caulking part 30 Bump stopper cap assembly 31 First bump stopper cap 31A End plate 31B Cutout part 31C Side plate 31D Open part 32 Second bump stopper cap 32A End plate 32B Cutout portion 32C Convex portion 32D Side plate 32E Open portion 40 Bump stopper cap assembly 41 First bump stopper cap 41A End plate 41B Cutout portion 41C Large diameter portion 41D Reduced diameter portion 41E Side plate 41F Open portion 41G groove 41H protrusion 42 Second bump stopper cap 42A End plate 42B Notch 42C Convex portion 42D Side plate 42E Hole 50 Bump stopper cap assembly 51 First bump stopper cap 51A End plate 51B Notch 51C side plate 51D recess 51E protrusions 52 second bump stopper cap 52A end plate 52B cutout portion 52C side plate 52D convex portion 52E recess

Claims (5)

[Claims] An eye joint is fixed to an outer end of a piston rod having a piston, and a piston rod assembly having a bump rubber is provided. The piston of the piston rod assembly is inserted into a damper tube, and In a shock absorber formed by projecting an outer end side of the piston rod assembly from an open end of a tube and caulking the open end of the damper tube, after caulking the open end of the damper tube, assembling a bump stopper cap. A method for assembling a shock absorber, wherein the shock absorber is fixed to an open end of a damper tube. 2. A piston rod assembly having an eye joint fixed to an outer end of a piston rod having a piston and a bump rubber provided, wherein a piston of the piston rod assembly is inserted into a damper tube, and In a shock absorber formed by projecting an outer end side of the piston rod assembly from an open end of a tube and caulking the open end of the damper tube, a bump stopper cap composed of a plurality of members is fixed to the open end of the damper tube. A bump stopper cap structure for a shock absorber, wherein a bump rubber contact surface of the bump stopper cap is made flat. 3. The bump stopper cap according to claim 1, wherein the bump stopper cap is a bump stopper cap assembly including a first bump stopper cap and a second bump stopper cap, and the first bump stopper cap is fitted around an end plate around the piston rod. Forming a U-shaped notch portion, and forming an opening in the side plate extending at a right angle from the end plate so as to extend at a right angle from the U-shaped notch portion, wherein the second bump stopper cap is provided on the end plate. A U-shaped notch fitted around the piston rod and a convex portion fitted into the notch of the first bump stopper cap are provided, and a side plate extending at a right angle from an end plate is formed at a right angle from the U-shaped notch. An opening is formed so as to extend from the first bump stopper cap, and both bump stopper caps are fitted so that the projections of the second bump stopper cap fit into the notches of the first bump stopper cap. 3. The bump stopper cap structure for a shock absorber according to claim 2, wherein the bumps are fixed to an open end of the damper tube in a state where the bumps are overlapped and connected. 4. The bump stopper cap according to claim 1, wherein the bump stopper cap is a bump stopper cap assembly including a first bump stopper cap and a second bump stopper cap, and the first bump stopper cap is fitted around an end plate around the piston rod. Forming a U-shaped notch portion to be fitted, providing a side plate having a large-diameter portion extending at a right angle from a circumferential half of the end plate and a reduced-diameter portion following the large-diameter portion, wherein the side plate has An open portion extending at a right angle from the U-shaped notch portion is provided, and the second bump stopper cap has a U-shaped notch portion fitted around the piston rod on an end plate and a notch portion of the first bump stopper cap. And a side plate extending at a right angle from a circumferential half of the end plate. A second bump stopper key is provided in a groove provided on the inner periphery of the enlarged diameter portion of the first bump stopper cap. The first bump stopper cap and the second bump stopper cap are connected by inserting the outer edge of the end plate of the cap, and the projection of the second bump stopper cap is fitted into the notch of the first bump stopper cap. So that the two bump stopper caps overlap with each other and
3. The bumper tube according to claim 2, wherein the protrusion or hole formed on the end plate of the bump stopper cap and the hole or protrusion formed on the end plate of the second bump stopper cap are fixed to the open end of the damper tube in a state of being engaged. The bump stopper cap structure of the described shock absorber. 5. The bump stopper cap assembly according to claim 1, wherein the bump stopper cap comprises a first bump stopper cap and a second bump stopper cap, wherein the first bump stopper cap has a semicircular end plate having the piston rod. Forming a U-shaped notch fitted around the end plate, and forming a concave portion or a convex portion at both circumferential end portions of a side plate extending at a right angle from the end plate, wherein the second bump stopper cap has a semicircular shape. A U-shaped notch fitted around the piston rod is formed in the end plate of the first bump stopper cap at the circumferential end of the side plate extending at a right angle from the end plate. Forming a convex or concave portion to be engaged with the first bump stopper cap by engaging the convex or concave portion of the second bump stopper cap with the concave or convex portion of the first bump stopper cap; 3. The bump stopper cap structure for a shock absorber according to claim 2, wherein the bump and the second bump stopper cap are coupled.