JPH0434261Y2 - - Google Patents

Description

[Detailed Description of the Invention] (Industrial Application Field) The present invention relates to the structure of a check seal for a hydraulic shock absorber.

(Prior Art) As a conventional check seal structure for a hydraulic shock absorber, for example, the one described in Japanese Patent Application Laid-open No. 179539/1983 is known.

As shown in FIG. 5, this conventional check seal structure includes a check seal member 01 and a reinforcing ring 02.
The check seal member 01 includes a lip portion 03 having an on-off valve function, and a cylinder 05.
A cylinder press-fitting part 04 is formed, which is press-fitted into the cylinder.
Further, the cylinder press-fitting portion 04 is formed at a portion on the inner peripheral side of the reinforcing ring 02 where outward deformation is restricted by the reinforcing ring 02, so that its inner diameter is smaller than the outer diameter of the cylinder 05. .

Therefore, in this conventional check seal structure, the check seal member 01 is attached by press-fitting the cylinder press-fitting part 4, which has an inner diameter smaller than the outer diameter of the cylinder 05, into one end of the cylinder 05.

(Problem to be solved by the invention) However, in the check seal structure of such a conventional hydraulic shock absorber, the cylinder press-fit portion 04, whose inner diameter is smaller than the outer diameter of the cylinder 05, is attached to the reinforcing ring. Because it was formed on the inner peripheral side of 02 and is subject to outward deformation control,
There was a problem that there was little escape area for the cylinder press-fitting part 04 during press-fitting, and the press-fitting load varied greatly depending on the inner diameter tolerance of the cylinder press-fitting part 04, resulting in poor workability and difficulty in achieving constant product accuracy.

Furthermore, as shown in FIG. 6, during the press-fitting of the cylinder press-fitting part 04,
Pushed out above cylinder 05, cylinder 05
This has caused problems such as those listed below.

Note that the cylinder press-fit portion 04 is more likely to break when the press-fit load is increased in order to solve the above-mentioned problem.

a) If the cylinder press-fit portion is caught, the check seal member may not be set correctly, and the opening/closing mechanism at the lip portion, which is the basic function of the check seal, may not be achieved.

b Assemble with the cylinder press-fit part sandwiched in,
If that part is subsequently cut off, the guide member and packing gland, which are connected to the check seal member and provided at one end of the cylinder, may become misaligned, reducing the fastening force and causing looseness. This may lead to a reduction in damping force and generation of abnormal noise.

c When the cylinder press-fitting part is cut off, the cut piece flows inside the hydraulic shock absorber and gets caught in each damping force valve, leading to a decrease in damping force.

(Means for Solving the Problems) In the present invention, the lip portion that opens and closes the circulation passage that communicates the seal chamber formed between the guide member and the rod seal and the reservoir chamber formed on the outer periphery of the cylinder is attached to the outer periphery. A check seal member having a reinforcing ring embedded in the inner periphery of the lip portion is press-fitted into the outer periphery of one end of the cylinder, and the reinforcing ring is connected to the one end of the cylinder and the guide member in the axial direction. In the check seal structure of the hydraulic shock absorber held between the cylinders, the check seal member is formed on the inner peripheral side of the reinforcing ring and is subject to outward deformation restriction, and the inner diameter is larger than the outer diameter of the cylinder. and a cylinder press-fit portion formed continuously with the cylinder loose-fit portion and in a portion not subject to outward deformation restriction of the reinforcing ring. It was a means to do so.

(Function) Therefore, in the check seal structure of the hydraulic shock absorber of the present invention, since the cylinder press-fitted portion is formed in a portion of the reinforcing ring that is not subject to outward deformation restriction, when press-fitting the check seal member, It is free to deform and spread outwards, preventing it from being pushed out to the end of the cylinder and from being pinched between itself and the cylinder.

Further, since the inner diameter of the cylinder loosely fitting portion on the inner peripheral side of the reinforcing ring is formed to be larger than the outer diameter of the cylinder, it will not be pushed and deformed by the cylinder during press fitting.

As described above, the cylinder press-fitted part of the check seal member has never been pushed out toward the end of the cylinder, or has been caught between one end of the cylinder and the guide member, and in addition, the cylinder has not been loosely fitted. Since there is no deformation of the lip part, the lip part can be correctly installed without being affected by press fitting.

(Example) Hereinafter, an example of the present invention will be described based on the drawings. As an example, a shock absorber used in an automobile suspension will be taken as an example.

As shown in FIGS. 1 and 2, the shock absorber A having the check seal structure of the embodiment includes a cylinder 10, an outer cylinder 20, a packing gland 30, a guide member 40, a piston rod 50, a rod seal member 60, and a check seal member. 80,
A reinforcing ring 90 is provided.

The cylinder 10 is cylindrical and includes a bottom body 14 having a communication hole 15 at the bottom, the upper end opening is closed by a guide member 40, the inside is filled with hydraulic fluid, and a piston 52 is slidably inserted.
It is divided into two chambers, an upper liquid chamber 12 and a lower liquid chamber 13.

One end of a piston rod 50 is connected to the piston 52, and the piston rod 50 passes through the guide member 40 and projects outside the cylinder 10, and its upper end is connected to a vehicle body member (not shown).

The piston 52 has through holes 511 and 512 that communicate between the upper liquid chamber 12 and the lower liquid chamber 13.
and plate valves 513, 514 that close the through holes 511, 512 from respective sides.

The lower outer periphery of the guide member 40 fits into the opening of the upper end 11 of the cylinder 10, and allows the piston rod 50 to freely slide into the small diameter portion 42 of the central through hole 43 via the bush 44 with a small gap. I am guiding you.

The outer cylinder 20 has a cylindrical shape with a bottom and is connected to the cylinder 1.
0 and the guide member 40, the rod seal 60 and the packing gland 30 are further inserted through the upper end opening, and the upper ends are crimped to accommodate these contents in a liquid-tight manner. .

That is, a reservoir chamber 21 is formed in the space between the outer tube 20 and the cylinder 10 and is filled with a desired amount of working fluid under the pressure of the sealed gas. It communicates with the lower liquid chamber 13 via the hole 15 .

Furthermore, an insulator and a mounting ring 22 are fixed to the lower end of the outer cylinder 20 for mounting on a vehicle axle or the like.

The packing gland 30 is fixed inside one end of the outer cylinder 20 as described above, and the rod seal member 60 is attached to the large diameter portion 31 facing downward of the through hole 33.

The rod seal member 60 has an outer circumferential portion press-fitted into the large diameter portion 31 of the packing gland 30, and an inner circumferential portion having a main lip that comes into elastic contact with the piston rod 50 and prevents hydraulic fluid etc. from leaking outside. 61, and a dust strip 62 that prevents muddy water and the like from entering from the outside.

A seal chamber 63 is formed between the rod seal 60 and the check seal 80, and the guide member 40 has a plurality of circulation passages 45 that open into the seal chamber 63 and open toward the check seal 80. It is perforated.

The check seal member 80 is attached to the cylinder 10.
The reinforcing ring 90 is attached to one end 11 of the ring by press-fitting and is formed into an annular shape made of rubber, and a reinforcing ring 90 is embedded therein. Incidentally, a vertical wall flange 91 extending downward is formed on the outer peripheral portion of the reinforcing ring 90.

Further, as shown in FIG. 3, the check seal member 80 is formed on the outer circumferential side of the reinforcing ring 90 and is disposed at the lower end of the circulation passage 45, and is connected from the seal chamber 63 to the reservoir 21. However, on the contrary, the inflow of the hydraulic fluid into the reservoir chamber 21 is allowed.
a lip portion 81 that opens and closes the circulation passage 45 to prevent pressurized gas from flowing into the seal chamber 63; It is formed in a portion m1 that is regulated from deforming to, and its inner diameter r1
is formed to be larger than the outer diameter r2 of the cylinder 10, and is continuous to the lower side of the cylinder loose fit portion 82, and is prevented from deforming outward by the vertical wall flange 91 of the reinforcing ring 90. A cylinder press-fitting part 83 is formed in a portion m2 that does not receive the cylinder 10 and protrudes downward, and has an inner diameter r3 smaller than an outer diameter r2 of the cylinder 10.

As shown in FIG. 4, the cylinder loosely fitting part 82 is arranged at a distance s without contacting the cylinder 10, and the cylinder press-fitting part 8
3 is pressure-fixed to the cylinder 10, and
The inner periphery of the reinforcing ring 90 is held between one end of the cylinder 10 and the guide member 40.

Next, the operation of the embodiment will be explained.

In the manufacturing process of the shock absorber A, when the check seal member 80 is attached to the cylinder 10, as the cylinder press-fitting part 83 is press-fitted into the cylinder 10 (Figs. 3 to 4), the cylinder press-fitting part 83 is Since there is no vertical wall flange 91 on the other side to restrict outward deformation, the cylinder press-fitting portion 83 can freely deform outward in response to the press-fitting load, and press-fitting can be performed smoothly.

Furthermore, since the inner diameter r1 of the cylinder loose fitting portion 82 is larger than the outer diameter r2 of the cylinder 10, the cylinder 10 is not pushed and deformed by the cylinder 10 when the check seal member 80 is press-fitted, and one end of the cylinder 10 is not deformed. 11 and the reinforcing ring 90.

Furthermore, as described above, the check seal member 80
In the cylinder loose fitting part 82 and cylinder press fitting part 8
The check seal member 80 is correctly attached to the cylinder 10, and the lip portion 81 provides stable on-off valve function.

In order to use the above-mentioned means, in the embodiment,
The features listed below are obtained.

a Since the cylinder press-fit portion 83 is not restricted from outward deformation by the vertical wall flange 91, variations in the press-fit load are reduced, and workability is improved.
Product accuracy is constant.

b. Since the lip portion 81 is installed correctly, a constant opening/closing valve function can be obtained.

c. There is no pinching of the inner part of the vertical wall flange 91 of the reinforcing ring 90 (the cylinder loose fitting part 82).
The tightening force of the guide member 40 and packing gland 30 connected to the check seal member 80 is less likely to decrease, and the damping force is less likely to decrease and abnormal noise is less likely to occur due to play caused by this. This also prevents looseness from occurring in this sandwiched part when it deteriorates over time.

d Furthermore, since it is difficult for a part of the check seal member 80 to be cut off due to the pinching of the check seal member 80, problems such as the cut part flowing inside the hydraulic shock absorber and getting caught in each damping force valve occur. hard.

Although the embodiments of the present invention have been described above in detail with reference to the drawings, the specific configuration is not limited to these embodiments, and the present invention may be modified without departing from the gist of the present invention. included.

For example, in the embodiment, the case where the present invention is applied to a shock absorber used in an automobile suspension is taken as an example, but the present invention is not limited to this and may be applied to other hydraulic shock absorbers.

(Effects of the invention) As explained above, in the check seal structure of the hydraulic shock absorber of the invention, the cylinder press-fitted portion of the check seal member is free to deform outward and is prevented from deforming significantly upward. In addition, the inner part of the reinforcing ring (cylinder loose fitting part) has never been pushed out to one end of the cylinder or has been caught between the cylinder and the reinforcing ring, and in addition,
Since the lip portion is installed correctly without being affected by press-fitting, the following effects can be obtained.

a Since the cylinder press-fit portion deforms freely without being restricted from outward deformation, variations in the press-fit load are reduced, workability is improved, and product accuracy is maintained.

b. Since the lip part is installed correctly, a constant opening/closing valve function can be obtained.

c Since there is no pinching of the cylinder loose fit part or cylinder press fit part, the tightening force of the guide member and packing gland connected to the check seal member is unlikely to decrease, and the damping force decreases due to play caused by this. Furthermore, when the sandwiched portion deteriorates over time, rattling is also prevented from occurring in the sandwiched portion.

d If the cylinder loose fitting part or the cylinder press-fitting part is cut due to pinching during press-fitting, it is unlikely that the cut piece will flow inside the hydraulic shock absorber and get caught in each damping force valve. hard.

[Brief explanation of the drawing]

Fig. 1 is an enlarged cross-sectional view of essential parts showing a check seal structure of a hydraulic shock absorber according to an embodiment of the present invention, Fig. 2 is a sectional view showing a shock absorber having a structure according to an embodiment of the present invention, Figs. 3 and 4. 5 is a cross-sectional view showing the main part of the structure of the embodiment of the present invention, and FIGS. 5 and 6 are cross-sectional views showing the structure of the conventional example. A...Shock absorber (hydraulic impactor), 1
0...Cylinder, 21...Reservoir chamber, 45...
Circulation passage, 63... Seal chamber, 80... Check seal member, 81... Lip portion 82... Cylinder loose fitting portion, 83 Cylinder press fitting portion, 90... Reinforcement ring.

Claims (1)

[Claims for Utility Model Registration] A lip part is provided on the outer periphery for opening and closing a circulation passage that communicates the seal chamber formed between the guide member and the rod seal with the reservoir chamber formed on the outer periphery of the cylinder. A check seal member having a reinforcing ring embedded in the inner circumferential side of the lip part is press-fitted into the outer periphery of one end of the cylinder, and the reinforcing ring is held between the one end of the cylinder and the guide member in the axial direction. In the check seal structure of a shock absorber, the check seal member is formed at an inner peripheral side of the reinforcing ring and is subject to outward deformation restriction, and the cylinder has an inner diameter larger than an outer diameter of the cylinder. A check of a hydraulic shock absorber characterized in that it has a loose fitting part and a cylinder press-fitting part formed continuously with the cylinder loose fitting part and in a part not subject to outward deformation restriction of the reinforcing ring. Seal structure.