JPH112280A - Strut damper mount joint fixing structure - Google Patents

Abstract

(57) Abstract: A seal member (51) is attached to a cap (12c) of a mount joint (12).
c is inserted into the inner cylinder 7, and then a surplus tip 7 e of the inner cylinder 7 is inserted.
Is bent inward to form the cap portion 12c.
Is fixed to the inner cylinder 7, a press-fitting portion 12h for press-fitting is formed on the cap portion 12c side, and a press-fitting portion 7d for storing the press-fitting portion 12h on the inner cylinder 7 side and determining an insertion position. Was formed. [Effect] The cap portion can be easily and accurately positioned on the inner cylinder, and the fixing of the mount joint portion to the inner cylinder is performed by press-fitting and crimping by bending, thereby reducing heat during welding. It can be fixed to the inner cylinder with sufficient bonding strength without being affected by spatter and without increasing the size of the mount joint.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a mounting structure for a strut damper.

[0002]

2. Description of the Related Art As a strut damper, for example, Japanese Unexamined Patent Publication No. 3-66942, entitled "Variable damping force type hydraulic shock absorber".
It has been known. The above-described technology provides a variable damping force type hydraulic shock absorber that has a high assembling workability, a high assembling accuracy, a greater degree of freedom in mounting on a vehicle, and a wider variable width of the damping force. As shown in FIG. 1 of the publication, the outer tube 11
An upper lid member 11c fixed to the upper end of the outer tube 11.
And

[0003]

In the above technique, the upper lid member 11c is press-fitted and fixed to the upper end opening of the outer tube 11. However, when a large damping force is generated, the connection strength is reduced by press-fitting only. Small and problematic. Therefore,
It is conceivable to weld the upper lid member 11c to the outer tube 11 over the entire circumference after press-fitting and fixing. However, at the time of welding, there is an inconvenience that cooling is required to prevent thermal distortion generated in the outer tube 11 and strict control is required so that welding spatter does not adhere to the outer surface of the sliding outer tube 11.

[0004] Further, although the upper lid member 11c is required to have sufficient strength, the upper lid member 11c must be made of low-carbon steel for welding, and the upper lid member 11c must be made thick to secure the thickness of the upper lid member 11c. There is a disadvantage that it becomes large. An object of the present invention is to fix a mount joint portion of a strut damper, which is not affected by heat or spatter during welding and does not increase the size of the mount joint portion by not using welding for mounting the mount joint portion to the inner cylinder. It is to provide a structure.

[0005]

According to a first aspect of the present invention, an inner cylinder is inserted into an outer cylinder via a shaft sealing device so as to be movable in the axial direction. In a strut damper to which a mount joint for mounting on a vehicle body is attached, a seal member is attached to a cap of the mount joint, and after inserting the cap into an inner cylinder, a surplus tip portion of the inner cylinder is bent radially inward. By this, the cap portion is fixed to the inner cylinder, a press-fit male portion for press-fitting is formed on the cap portion side, and a press-fit female portion for storing the press-fit male portion on the inner cylinder side and determining the insertion position is provided. Formed.

[0006] The cap portion can be easily and accurately positioned on the inner tube, and the mounting joint portion is fixed to the inner tube by press-fitting and crimping, thereby reducing heat during welding. It can be fixed to the inner cylinder with sufficient bonding strength without being affected by spatter and without increasing the size of the mount joint.

[0007]

Embodiments of the present invention will be described below with reference to the accompanying drawings. The drawings should be viewed in the direction of reference numerals. FIG. 1 is a cross-sectional view of a strut damper according to the present invention at the maximum extension.
An upper oil seal 3 provided at an upper end portion of an inner surface of the outer cylinder 2 and an upper bearing 4 thereunder; a lower bearing 5 provided at an intermediate portion of the outer cylinder 2 and a lower oil seal 6 thereunder; An inner cylinder 7 movably inserted into the lower oil seals 3 and 6 and the upper and lower bearings 4 and 5, and a free piston inserted into the inner cylinder 7 to separate the upper gas chamber G and the oil chamber. 8

The strut damper 1 includes a mount joint 12 fixed to the upper end of the inner cylinder 7, a joint bolt 12b formed on the mount joint 12, and a dust into which the joint bolt 12b is inserted. A cover 13 and an upper spring seat 14,
A bump stopper rubber 15 fitted to the outer surface of the upper inner cylinder 7 in the dust cover 13, a rod 17 extending upward from a bottom lid 16 attached to the bottom of the outer cylinder 2,
And a piston 18 which is attached to the upper end of the cylinder and partitions the oil chamber in the inner cylinder 7 into an upper oil chamber S1 and a lower oil chamber S2. In addition,
The mount joint portion 12 is a member that interposes the mount portion 11 for reducing a shock transmitted from the strut damper 1 to the vehicle body when the strut damper 1 is mounted on the vehicle body, between the vehicle body and the mount joint portion 12.

Further, the strut damper 1 has a shaft sealing device 21 attached to a lower portion of the inner cylinder 7 to support the rod 17, and a lower spring seat 22 attached to an outer surface of an intermediate portion of the outer cylinder 2.
A suspension spring 23 disposed between the lower spring seat 22 and the upper spring seat 14;
And a mounting portion 24 provided for mounting to a knuckle (not shown) on the wheel side at a lower portion of the vehicle. 2a is a step for positioning the lower side of the lower bearing 5 and the lower oil seal 6; 8a is an O-ring attached to the free piston 8;
Reference numeral denotes a distance collar inserted into the inner surface of the outer cylinder 2 for positioning the upper oil seal 3 and the upper bearing 4 with respect to the lower bearing 5 and the lower oil seal 6.

FIG. 2 is an enlarged sectional view of a piston and a shaft sealing device of the strut damper according to the present invention. The piston 18 includes a washer 31, a compression valve 32, a piston body 33, and an extension valve 34. , And a washer 35 are sequentially inserted into a small-diameter portion 17a formed at the upper end of the rod 17, and fixed with a nut N1. Piston body 3
Reference numeral 3 denotes extension-side oil passages 33a and 33 through which hydraulic oil passes during the extension stroke.
a, contraction side oil passages 33b, 33 through which hydraulic oil passes during the contraction stroke.
b. Reference numeral 36 denotes a stopper rubber.

The shaft sealing device 21 includes a rod guide 42 positioned by a ring 41 fixed to the inner cylinder 7, a bush 43 provided on the rod guide 42 for sliding the rod 17, and a rod guide 42. And a lip seal fixing member 45 to which the lip seal 44 is baked and fixed. The lip seal 44 is pressed into the inner surface of the inner cylinder 7 by applying the lip seal 44 to the lip seal fixing member 45. And a press-fitting fixing member 46 which is bent and fastened by crimping or the like.

The operation of the piston 18 during the extension stroke described above will now be described. In the extension stroke in which the piston 18 and the outer cylinder 2 are lowered with respect to the inner cylinder 7, the hydraulic oil in the lower oil chamber S2 passes through the extension oil passages 33a, 33a as indicated by the arrows, and passes through the extension valve 34. To open the upper oil chamber S1. At this time, an extension-side damping force is generated.

FIG. 3 is a sectional view of the strut damper according to the present invention at the time of maximum compression, and shows a state in which the upper end of the outer cylinder 2 collides with the bump stopper rubber 15 to reduce the impact at the time of maximum compression.

FIG. 4 is an enlarged sectional view of the piston portion of the strut damper according to the present invention. In the contraction stroke in which the piston 18 and the outer cylinder 2 rise with respect to the inner cylinder 7, the upper oil chamber S
As shown by the arrow, the hydraulic oil in the compression oil passage 1
The compression valve 32 is pushed open through b and 33b to reach the lower oil chamber S2. At this time, a damping force on the contraction side is generated.

FIG. 5 is an enlarged cross-sectional view of the joint between the upper end of the inner cylinder and the mount joint according to the present invention.
Are a large-diameter inner surface portion 7b having an inner diameter larger than the inner surface 7a, and an inner-surface stepped portion 7c formed between the inner surface 7a and the large-diameter inner surface portion 7b.
And The large-diameter inner surface portion 7b is obtained by enlarging the inner surface 7a by machining or the like.
It was formed together when forming b. The large-diameter inner surface 7b and the inner step 7c constitute a press-fitting portion 7d.

The mount joint portion 12 comprises a joint bolt portion 12b having a screw 12a formed on the upper portion, and a cap portion 12c connected to the inner cylinder 7. The cap portion 12c is inserted into the inner surface 7a of the inner cylinder 7 with a clearance, and has an O-ring groove 12d having an O-ring 51 mounted therein, and a press-fit that press-fits into the large-diameter inner surface portion 7b of the inner cylinder 7. Part 12f, the insertion part 12e and the press-fitting part 1
An outer diameter step 12g formed between 2f. The press-fitting portion 12f and the outer diameter step portion 12g constitute a press-fitting portion 12h.

The procedure for assembling the mount joint 12 to the upper end of the inner cylinder 7 described above will now be described. FIG. 6 (a)
FIGS. 7A to 7C are action diagrams for explaining a procedure for assembling a mount joint to the upper end of the inner cylinder according to the present invention, wherein FIG. 9A is a state before assembling, and FIG. And (c) shows a state in which the assembly is completed.
5A, the O-ring 51 is mounted on the O-ring groove 12d of the mount joint 12, and the insertion portion 12e of the mount joint 12 is inserted into the inner surface 7a of the inner cylinder 7. Mount joint 1 on 7b
The second press-fitting portion 12f is press-fitted.

In FIG. 2B, the outer joint 12g of the mount joint 12 is brought into contact with the inner step 7c of the inner cylinder 7 to position the mount joint 12 relative to the inner cylinder 7. In (c), an extra end portion 7e of the inner cylinder 7 protruding from the cap portion 12c of the mount joint portion 12
(See also FIG. 6 (b).) And the mount joint portion 12 is fixed to the inner cylinder 7 by caulking with roller caulking or the like.

As described above, the O-ring 51 is attached to the cap portion 12c of the mount joint portion 12, and after inserting the cap portion 12c into the inner cylinder 7, the excess portion 7e at the distal end of the inner cylinder 7 is bent radially inward. Thereby, the cap portion 12c is fixed to the inner cylinder 7, and the cap portion 12c
A press-fitting male part 12h (see FIG. 5) for press-fitting is formed on the side c, and a press-fitting female part 7d (see FIG. 5) for storing the press-fitting male part 12h and determining the insertion position is formed on the inner cylinder 7 side. By doing so, the cap portion 12c can be easily and accurately positioned on the inner cylinder 7.

The mount joint 1 to the inner cylinder 7
Since the fixing of 2 is performed by press-fitting and crimping by bending, the heat generated at the time of welding does not impair the sealing function of the O-ring 8a (see FIG. 1) of the free piston 8 (see FIG. 1). The spatter scattered during welding does not adhere to the outer surface of the inner cylinder 7 without impairing the sliding of the outer surface of the inner cylinder 7,
Further, without increasing the size of the mount joint 12, the mount joint 1 is attached to the inner cylinder 7 with sufficient bonding strength.
2 can be fixed.

In the mount joint fixing structure of the present invention, the outer surface of the cylinder member for fixing the mount joint portion 12 does not slide, and the shock absorber provided with a free piston in the cylinder, or the outer surface of the cylinder member is The present invention can be applied to a sliding shock absorber, and may be applied to a shock absorber other than the strut damper described in the present embodiment.

[0022]

According to the present invention, the following effects are exhibited by the above configuration. In the structure for fixing a mount joint of a strut damper according to claim 1, a seal member is attached to a cap of the mount joint, and after inserting the cap into the inner cylinder, a surplus end of the inner cylinder is bent radially inward. The cap part is fixed to the inner cylinder by forming a press-fit male part for press-fitting on the cap part side, and a press-fit female part for storing the press-fit male part on the inner cylinder side and determining the insertion position is formed As a result, it is possible to easily and accurately position the cap portion on the inner cylinder, and by fixing the mount joint to the inner cylinder by press-fitting and crimping by bending, heat and heat during welding can be reduced. It can be fixed to the inner cylinder with sufficient bonding strength without being affected by spatter and without increasing the size of the mount joint.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of a strut damper according to the present invention at the maximum extension.

FIG. 2 is an enlarged sectional view of a piston and a shaft sealing device of the strut damper according to the present invention.

FIG. 3 is a cross-sectional view of the strut damper according to the present invention at the time of maximum compression.

FIG. 4 is an enlarged sectional view of a piston portion of the strut damper according to the present invention.

FIG. 5 is an enlarged sectional view of a joint portion between the upper end portion of the inner cylinder and the mount joint portion according to the present invention.

FIG. 6 is an operation diagram illustrating a procedure for assembling a mount joint to the upper end of the inner cylinder according to the present invention;

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Strut damper, 2 ... Outer cylinder, 7 ... Inner cylinder, 7d ... Press-fitting part, 7e ... Extra tip part, 12 ... Mount joint part, 12h ... Press-fitting male part, 21 ... Shaft sealing device, 51 ...
Seal member (O-ring).

Claims (1)

[Claims] 1. A strut damper having an inner cylinder inserted axially movably into an outer cylinder via a shaft sealing device, and a mount joint for mounting to a vehicle body attached to a tip of the inner cylinder. By attaching a seal member to the cap part, inserting this cap part into the inner cylinder, and then bending the surplus end of the inner cylinder radially inward,
A structure in which the cap portion is fixed to the inner cylinder, a press-fit male portion for press-fitting is formed on the cap portion side, and a press-fit female portion for storing the press-fit male portion on the inner cylinder side and determining an insertion position is formed. The strut damper mount joint fixing structure.