JP2003065381A - Dust cover fixing structure of hydraulic shock absorber - Google Patents

Abstract

(57) [Summary] [Problem] To improve the assemblability of fixing a dust cover to a damper tube side. In a dust cover fixing structure of a hydraulic shock absorber (10), a flange portion (40) is provided on the damper tube (11) side, and the dust cover (30) is provided at an end of the dust cover (30).
An abutting portion 32 that abuts against the flange portion 40 is provided continuously to the bellows portion 31, a skirt portion 33 with reduced rigidity is extended from the abutting portion 32, and the flange portion 40 is extended to the extending end of the skirt portion 33. Provided with a locking portion 34 to be locked to.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a dust cover fixing structure for a hydraulic shock absorber.

[0002]

2. Description of the Related Art A conventional dust cover fixing structure for a hydraulic shock absorber has a structure in which a flange portion is provided on the side of a damper tube for mounting the dust cover as described in Japanese Utility Model Laid-Open No. 1-165343. The engaging groove provided at the end of the is engaged with the flange. According to this, even when the end portion of the dust cover contracts the piston rod, the end portion of the dust cover does not come into contact with the spring seat, so that the coated surface of the spring seat can be prevented from peeling off and rusting.

[0003]

In the prior art, the rigidity of the dust cover around the locking groove is high, and the end of the dust cover is inserted from the insertion direction when the dust cover is assembled to lock the flange. The locking groove cannot be expanded and deformed simply by pressing it against the flange portion. For this reason, it is necessary to pull the end of the dust cover strongly in the insertion direction by a person's hand, forcibly expand and deform the locking groove, and hook and lock it on the flange portion, resulting in poor assembly.

Therefore, it is very difficult to automate the work of fixing the dust cover to the damper tube side in the automatic machine.

An object of the present invention is to improve the assembling property of fixing the dust cover to the side of the damper tube so that the dust cover can be assembled even by an automatic machine without manpower.

[0006]

According to a first aspect of the present invention, there is provided a dust cover fixing structure which is attached to a piston rod side of a hydraulic shock absorber and covers a piston rod penetrating portion of a damper tube. The end portion of the dust cover is provided with an abutting portion that is in contact with the flange portion continuously from the bellows portion of the dust cover, and a skirt portion having reduced rigidity is extended from the abutting portion to form a skirt portion. An engaging portion for engaging the flange portion is provided at the extending end of the.

According to a second aspect of the present invention, in addition to the first aspect of the present invention, the flange portion includes a plurality of overhang portions which are separated from each other in the circumferential direction of the damper tube.

According to a third aspect of the present invention, in addition to the first or second aspect of the invention, the flange portion is provided with a tapered guide portion that expands in diameter in the insertion direction of the dust cover.

According to a fourth aspect of the present invention, in addition to any one of the first to third aspects, the formation surface of the engaging portion of the dust cover extending in the circumferential direction of the dust cover is the center axis of the dust cover. On the other hand, it is a diagonal cross.

According to a fifth aspect of the present invention, in addition to any one of the first to fourth aspects, the end portion of the dust cover is partially cut out, and the abutting portion, the skirt portion and the locking portion are assembled. ,
It is provided at each of a plurality of positions separated from each other in the circumferential direction of the dust cover.

[0011]

According to the invention of claim 1, the following effects are obtained. The skirt portion having low rigidity between the contact portion and the locking portion of the dust cover is easily deformed. Therefore, when assembling the dust cover, if you press the locking part at the end of the dust cover against the flange part on the damper tube side from the insertion direction, the skirt part elastically deforms and the locking part opens and the locking After the portion has passed over the flange portion, the portion is locked to the flange portion so that the dust cover can be fixed to the damper tube side.

In the use stage, when the bellows portion of the dust cover is compressed when the piston rod contracts, the contact portion at the end portion of the dust cover comes into contact with the flange portion at the damper tube side, and as a result, the dust cover. It is possible to prevent the ends of the spring sheet from coming into contact with the spring sheet, and to prevent the coated surface of the spring sheet from peeling and rusting. Also, when the piston rod extends, even if the bellows part of the dust cover extends,
The locking part at the end of the dust cover is locked to the flange part on the damper tube side to prevent the dust cover from coming off.

According to the invention of claim 2, there is the following action. Since the flange part on the damper tube side consists of a plurality of overhanging parts that are spaced apart from each other, the dust cover can be more easily attached when the dust cover is assembled than when a continuous flange part is provided on the entire circumference of the damper tube. When the locking portion is locked to the flange portion on the side of the damper tube, the dust cover is partially deformed, the amount of deformation is small, and the dust cover is easily deformed, and the insertion is easy. In addition, the space between the adjacent overhanging portions of the flange portion can be secured as an air vent passage when the bellows portion of the dust cover expands and contracts.

According to the invention of claim 3, there is the following action. Since the flange part on the damper tube side has a tapered guide part, when the dust cover end part is pressed against the flange part during assembly of the dust cover, the guide part The taper of the part enables centering and smooth insertion. Even in the dust cover removal direction, the outer edge of the flange part where the dust cover locking part locks extends outward along the taper of the guide part, so that the locking part is securely hooked and the dust cover is pulled out. To prevent.

According to the invention of claim 4, there is the following action. The formation surface of the engaging portion of the dust cover extending in the circumferential direction of the dust cover was obliquely intersected with the central axis of the dust cover. Therefore, when assembling the dust cover, the locking portion at the end of the dust cover does not press the entire circumferential direction against the flange portion on the damper tube side at a time. It will be pressed from the existing part to the flange part. Therefore, the preceding locking portion is expanded in order to get over the flange portion, and the locking portion is more easily inserted.

According to the invention of claim 5, there is the following action. By partially notching the end portion of the dust cover and providing a set of the contact portion, the skirt portion, and the locking portion at each of a plurality of positions that are separated from each other in the circumferential direction of the dust cover, the damper described above is provided. The same advantage can be obtained by forming the flange portion on the tube side from a plurality of protrusions. That is, the dust cover can be easily deformed to improve the insertability, and the notched portion can be secured as an air vent channel.

[0017]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a cross-sectional view showing a main part of a hydraulic shock absorber, FIG. 2 is a plan view of FIG. 1, FIG. 3 shows a flange portion provided on a bump stopper cap, and (A) is a half cross-sectional view. ,
(B) is a cross-sectional view of an essential part of a modified example, (C) is a cross-sectional view of an essential part of another modified example, and FIG. 4 shows a bump stopper cap.
(A) is a front view, (B) is a plan view, (C) is C of (B).
FIG. 5 is a sectional view taken along line C, and FIG. 5 is a sectional view showing the dust cover.

The hydraulic shock absorber 10 is a strut damper type, and as shown in FIGS. 1 and 2, the piston rod 12 is inserted into a cylinder (not shown) built in an outer tube 11 (damper tube), and the outer damper 11 is inserted. A piston rod 1 that is provided with a wheel-side mounting bracket 13 on the tube 11 and is coupled to a wheel, and that projects from the outer tube 11
The vehicle body side mounting bracket 14 is attached to the vehicle body 2 to be mounted on the vehicle body. The vehicle body side mounting bracket 14 includes a bearing 15 inserted in the upper end portion of the piston rod 12 and a nut 16
It is composed by concluding with.

The hydraulic shock absorber 10 has a suspension spring 19 between a lower spring seat 17 fixed to the outer circumference of the outer tube 11 and an upper spring seat 18 installed around the piston rod 12 and back-supported by a bearing 15. Is intervening.

The hydraulic shock absorber 10 is provided with a stabilizer bracket 20 on the outer tube 11 to which a stabilizer is connected.

The hydraulic shock absorber 10 is provided with a bump rubber 25 which is firmly attached to the lower portion of the mounting rod 14 of the piston rod 12 on the vehicle body side. Hydraulic shock absorber 10
Is a bump stopper cap 26 in which the bump rubber 25 is attached to the upper end portion of the outer tube 11 at the time of maximum compression.
The maximum compression stroke is regulated by abutting against the stopper plate 27. The bump rubber 25 is the outer tube 11
The dust cover 30 covering the upper end opening is continuously provided on the lower end side, and the structure of the dust cover 30 will be described later.

That is, the hydraulic shock absorber 10 expands and contracts so that the impact force received by the vehicle from the road surface is absorbed by the elastic force of the suspension spring 19. When the piston (not shown) moves up and down as the hydraulic shock absorber 10 expands and contracts, the hydraulic shock absorber 10 expands and contracts due to the damping force generated by the piston valve device provided in the piston, the base valve device provided in the cylinder, and the like. Is quickly suppressed.

However, the hydraulic shock absorber 10 is provided with the dust cover 30 which covers the periphery of the seal portion, which is penetrated by the piston rod 12, at the upper end portion of the outer tube 11 to which the bump stopper cap 26 is attached. The dust cover 30 has a cylindrical bellows portion 31 that covers the upper end portion of the outer tube 11, and protects the piston rod 12 and the seal portion from dust such as water and mud.

The dust cover 30 is integrally formed from the bump rubber 25, and the bump rubber 25 has an abutting surface 2 with the stopper plate 27 of the bump stopper cap 26.
It extends downward from a connecting portion 25B provided outside 5A.

As shown in FIGS. 3 and 4, the bump stopper cap 26 attached to the outer tube 11 is integrally provided with a flange portion 40 for fixing the lower end portion of the dust cover 30. The flange portion 40 includes a plurality of (for example, 2 to 4) protruding portions 41 that are separated from each other in the circumferential direction of the outer tube 11.

The lower end of the dust cover 30 is shown in FIGS.
As shown in FIG. 3, a thick annular contact portion 32 that continuously contacts the bellows portion 31 and contacts the flange portion 40 is provided.
A thin annular skirt portion 33 having reduced rigidity is extended from the above, and an annular engaging portion 34 that engages with the flange portion 40 is provided on the inner circumference of the extending end of the skirt portion 33. The contact portion 32 is a horizontal contact surface 32A orthogonal to the central axis of the dust cover 30.
The skirt portion 33 has a tapered fitting surface 33A obliquely intersecting the central axis of the dust cover 30, and the locking portion 34 has a tapered guided surface 34A obliquely intersecting the central axis of the dust cover 30 (see FIG. 3). (A)). When the dust cover 30 is assembled, the guided surface 34A of the locking portion 34 of the dust cover 30
Is pressed against the flange portion 40 from the insertion direction, the skirt portion 33 elastically deforms and the locking portion 34 expands, and the locking portion 34
After the flange portion 40 is overcome, the skirt portion 33 is elastically restored and is locked to the flange portion 40. The flange portion 40 is held inside the fitting surface 33A of the skirt portion 33, and the dust is retained. Connect the lower end of the cover 30 to the outer tube 1
Fix on the side of 1.

As shown in FIGS. 3 and 4, each of the overhanging portions 41 constituting the flange portion 40 of the bump stopper cap 26 has a disk portion 42 overhanging around the lower end outer periphery of the bump stopper cap 26 and a circle. It is composed of a tapered guide portion 43 that expands in a tapered shape from the outer edge of the plate portion 42 along the insertion direction of the dust cover 30. Guide part 4 of the flange part 40
3 is the dust cover 3 when the dust cover 30 is assembled.
When the guided surface 34A of the locking portion 34 of 0 is pressed against the flange portion 40, the guided surface 34A of the locking portion 34 is centered by the taper of the guide portion 43 to smooth the insertion and the dust cover 30. The locking portion 34 of is locked to the outer edge of the guide portion 43.

The taper angle of the guide portion 43 of the flange portion 40 (angle with respect to the central axis of the bump stopper cap 26) is the taper angle of the fitting surface 33A of the skirt portion 33 of the dust cover 30 (dust cover 30). Angle formed with respect to the central axis of the dust cover 30
It is possible to easily hook the engagement portion 34 of the above with the guide portion 43 of the flange portion 40, and to make it difficult to remove the dust cover 30.

The outer diameter of the flange portion 40 (the guide portion 4
3) has a smaller diameter than the inner diameter (fitting surface 33A) of the skirt portion 33 of the dust cover 30.
To make it easier to insert.

According to this embodiment, there are the following effects. The low-rigidity skirt portion 33 between the contact portion 32 and the locking portion 34 of the dust cover 30 is easily deformed. Therefore, when the dust cover 30 is assembled, when the engaging portion 34 at the end portion of the dust cover 30 is pressed against the flange portion 40 on the outer tube 11 side from the insertion direction, the skirt portion 33 elastically deforms and the engaging portion 34. And the locking portion 34 is extended to the flange portion 40.
After overcoming the above, the dust cover 30 can be fixed to the outer tube 11 side by being locked to the flange portion 40.

In the use stage, when the bellows portion 31 of the dust cover 30 is compressed when the piston rod 12 contracts, the contact portion 32 at the end portion of the dust cover 30 contacts the flange portion 40 on the outer tube 11 side. And as a result,
It is possible to prevent the end portion of the dust cover 30 from coming into contact with the spring seat 17, and to prevent the coated surface of the spring seat 17 from peeling and rusting. Also, the piston rod 12
Even when the bellows portion 31 of the dust cover 30 is extended, the engaging portion 34 at the end portion of the dust cover 30 is engaged with the flange portion 40 on the outer tube 11 side to prevent the dust cover 30 from coming off.

Flange portion 4 on the outer tube 11 side
Since 0 is composed of a plurality of overhanging portions 41 which are separated from each other, the dust cover 30 is assembled at the time of assembly of the dust cover 30 as compared with the outer tube 11 which is provided with the continuous flange portion 40. When the locking portion 34 is locked to the flange portion 40 on the outer tube 11 side, the dust cover 30 is partially deformed, the amount of deformation is small, and the dust cover 30 is easily deformed and easily inserted. In addition, the space between the adjacent overhanging portions 41 of the flange portion 40 can be secured as an air vent passage when the bellows portion 31 of the dust cover 30 expands and contracts. In the bump stopper cap 26, in addition to the air vent channel formed by the space between the adjacent protrusions 41 of the flange portion 40, the bump stopper cap 26 has a notch portion that serves as an air vent channel. 44 (FIG. 3) or notch 45
(FIG. 4) can also be formed.

Flange portion 4 on the outer tube 11 side
Since 0 has a tapered guide portion 43,
When the engaging portion 34 at the end portion of the dust cover 30 is pressed against the flange portion 40 when the dust cover 30 is assembled, the engaging portion 34 can be centered by the taper of the guide portion 43 so that the insertion can be smoothly performed. Also, the dust cover 3
Even in the pull-out direction of 0, the outer edge of the flange portion 40 with which the locking portion 34 of the dust cover 30 is locked extends outward along the taper of the guide portion 43, so that the locking portion 34 is reliably caught and the dust cover Prevent 30 from coming off.

The present invention can employ the following modifications. (1) The overhanging portion 41 of the flange portion 40 connects the straight guide portion 46 to the outer edge of the disc portion 42 (see FIG. 3).
(B)), or one consisting only of the disc portion 42 (FIG. 3)
(C)) may be used.

(2) The surface of the locking portion 34 of the dust cover 30 that extends in the circumferential direction of the dust cover 30 may be oblique to the central axis of the dust cover 30. According to this, when the dust cover 30 is assembled, the dust cover 3
The engaging portion 34 at the end portion of 0 does not press the entire circumferential direction against the flange portion 40 on the outer tube 11 side at a time, but the flange portion 40 from the portion preceding in the insertion direction of the dust cover 30. It will be pressed against. Therefore, the locking portion 34 is opened in order from the preceding locking portion 34 so as to get over the flange portion 40, and the locking portion 34 is more easily inserted.

(3) The lower end portion of the dust cover 30 is partially cut out in the circumferential direction (cutout portion 35 in FIG. 5), and the contact portion 3 is formed.
The set of 2, the skirt portion 33, and the locking portion 34 may be provided at each of a plurality of positions (for example, 2 to 4 positions) separated from each other in the circumferential direction of the dust cover 30. According to this, the flange portion 40 on the outer tube 11 side as described above.
The same merit can be obtained by using a plurality of overhanging portions 41. That is, the dust cover 30 can be easily deformed to improve the insertability, and the notched portion (notched portion 35) can be secured as the air vent channel. In this case, the overhanging portion 41 of the flange portion 40 may be continuous over the entire circumference of the outer tube 11 in the circumferential direction.

Although the embodiment of the present invention has been described in detail with reference to the drawings, the specific configuration of the present invention is not limited to this embodiment, and the design can be changed without departing from the gist of the present invention. Etc. are included in the present invention. For example, the flange portion provided on the damper tube side may be provided separately from the bump stopper cap. The dust cover may be separate from the bump rubber.

[0038]

As described above, according to the present invention, the assemblability of fixing the dust cover to the damper tube side can be improved.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of essential parts showing a hydraulic shock absorber.

FIG. 2 is a plan view of FIG.

3A and 3B show a flange portion provided on a bump stopper cap, FIG. 3A is a half sectional view, FIG. 3B is a sectional view of a main portion of a modified example, and FIG. 3C is a sectional view of a main portion of another modified example. It is a figure.

FIG. 4 shows a bump stopper cap (A).
Is a front view, (B) is a plan view, and (C) is a cross-sectional view taken along line CC of (B).

FIG. 5 is a cross-sectional view showing a dust cover.

[Explanation of symbols]

10 hydraulic shock absorber 11 Outer tube (damper tube) 12 piston rod 30 dust cover 31 bellows 32 Contact part 33 Skirt 34 Locking part 35 notch 40 Flange 43 Tapered guide

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Kenichiro Kaneko             1-14 Fujiwara-cho, Gyoda-shi, Saitama 1 Stock             Company Showa Saitama Head Office Factory F term (reference) 3J045 AA14 BA02 CB14 CB21 EA10                 3J069 AA50 CC29 CC30 DD48

Claims (5)

[Claims] 1. A fixed structure of a dust cover which is attached to a piston rod side of a hydraulic shock absorber and covers a piston rod penetrating portion of a damper tube, wherein a flange portion is provided on the damper tube side, and an end portion of the dust cover is provided. An abutting portion is provided continuously with the bellows portion of the dust cover to abut the flange portion, and a skirt portion having reduced rigidity is extended from the abutting portion, and the extended end of the skirt portion is locked to the flange portion. A dust cover fixing structure for a hydraulic shock absorber, which is provided with a locking portion. 2. The dust cover fixing structure for a hydraulic shock absorber according to claim 1, wherein the flange portion includes a plurality of projecting portions that are separated from each other in the circumferential direction of the damper tube. 3. The dust cover fixing structure for a hydraulic shock absorber according to claim 1, wherein the flange portion includes a tapered guide portion whose diameter increases along the insertion direction of the dust cover. 4. The hydraulic pressure according to claim 1, wherein a forming surface of the engaging portion of the dust cover extending in the circumferential direction of the dust cover is obliquely intersected with a central axis of the dust cover. Dust cover fixing structure for shock absorber. 5. An end portion of the dust cover is partially cut away, and a set of the contact portion, the skirt portion and the locking portion is provided at each of a plurality of positions spaced apart from each other in the circumferential direction of the dust cover. A dust cover fixing structure for a hydraulic shock absorber according to any one of claims 1 to 4.