JPH0511399Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to an improvement of a shock absorber related to shock absorbing technology.

[Prior Art] As an example of this type of absorber, the one shown in FIG. 3 has been known. That is, in the figure, numerals 1 and 2 indicate an oil cylinder and a gas tube which are arranged concentrically with each other, and a rod guide 3 fixed to the upper end of the former oil cylinder 1.
The outer peripheral edge of the gas tube 2 is in airtight contact with the inner diameter surface of the latter gas tube 2. Code 5 is this rod guide 3
A piston (not shown) that reciprocates within the oil chamber 6 is attached near its lower end. Reference numeral 7 denotes an oil seal having a main lip 8 made of a rubber-like elastic material that is in close contact with the circumferential surface of the rod 5.
The base of the rod guide 3 is brought into contact with the tip of an annular projection 9 protruding from the upper end surface of the rod guide 3, and the outer diameter end of the support ring 10 on which the rubber-like elastic material is baked is brought into contact with the outer peripheral projection 11 on the upper end surface of the rod guide 3. and the bent upper end portion 12 of the gas tube 2 by caulking. A check valve lip 13 is provided on the lower side of the oil seal 7 and is connected to and separated from the outer diameter surface of the annular protrusion 9 by a rubber-like elastic material that is integrally connected to the main lip 8. 7. The space surrounded by the rod guide 3 and the rod 5 is divided into an outer space 14 in front of the rod guide and an inner space 15 in the rear thereof. Reference numeral 16 is a communication notch formed in the annular protrusion 9, and 17 is a communication path that communicates the outer space 14 with the reservoir chamber 18. Pressure gas is sealed in the reservoir chamber 18.

The shock absorber with the above configuration has rod 5
One of the oil cylinder 1 and the gas tube 2 is connected to the supporting body side, and the other to the supported body side, and serves to speed up the damping of vibrations generated on the latter side. When the pressure in the oil chamber 6 rises to
Even if a part of the oil in the oil chamber 6 flows out from between the rod 5 and the rod guide 3, it is configured so as not to leak to the outside. That is, the oil flowing out from between the rod 5 and the rod guide 3 is prevented from leaking to the outside by the tight sliding between the main lip 8 of the oil seal 7 and the circumferential surface of the rod 5, and is gradually stored in the inner space 15. , the check valve lip 13 is opened through the communication notch 16, and the oil flows into the reservoir chamber 18 through the outer space 14 and the communication passage 17, and mixes with the oil present below the reservoir chamber 18. Further, when the rod 5 is lowered, the pressure in the oil chamber 6 decreases, but since the check valve lip 13 is pressed against the outer diameter surface of the annular projection 9, the pressure gas in the reservoir chamber 18 and the outer space 14 is It is configured so that it does not flow into the space 15 side.

[Problems to be Solved by the Invention] However, according to the above-mentioned conventional example, regarding its manufacture, the check valve lip 13 provided integrally with the oil seal 7 is not aligned radially with respect to the outer diameter surface of the annular projection 9 of the rod guide 3. Since the lip 13 is in contact with the oil seal 7, the tightening of the lip 13 may become unstable due to seal assembly, caulking, eccentric installation, etc., or the support ring 10 of the oil seal 7 may become unstable during caulking.
Since the outer circumferential protrusion 11 of the rod guide 3 and the bent upper end 12 of the gas tube 2 are in metal contact, a gap is created due to variations in caulking, and there is a problem in that the sealing performance of this part is poor. Furthermore, in order to solve this problem, if the rubber-like elastic material is made thicker up to the outer periphery of the support ring 10 of the oil seal 7 which is caulked between the rod guide 3 and the gas tube 2, the elastic material 23 will have a large volume. ,
This sagging causes play in the seal, and a new problem arises in that the caulking load is not stable and the axial position of the oil seal is not constant.

Check valve lip 1 as shown in Figure 3
In the case of a structure in which the oil seal 3 contacts the outer diameter surface of the annular projection 9, the above-mentioned displacement of the axial position of the oil seal does not have a large effect on the sealing performance.

However, if the check valve lip is in contact with the axial end face, any deviation in the axial position of the oil seal will greatly deteriorate the sealing performance.

[Means for Solving the Problems] In view of the above points, the present invention maintains the contact pressure of the check valve lip against the mating member at a constant level during assembly, maintains sufficient sealing performance of the caulked portion, and also prevents oil leakage. The purpose is to provide a shock absorber with strong and complete seal retention.To achieve this purpose, an oil cylinder and a gas tube, which are concentrically connected to each other and form a reservoir chamber in the middle, are connected to each other. a piston and a rod that reciprocate within the oil cylinder; a rod guide that is fixed to an end of the oil cylinder, cooperates with the oil cylinder and the rod to form an oil chamber, and slidably supports the rod; A main lip made of a rubber-like elastic material that is in close contact with the circumferential surface of the rod, and a check valve lip that approaches and separates from the outer end surface of the rod guide, and a support ring to which these lips are fixed is provided protruding from the outer end surface of the rod guide. An oil seal is caulked and fixed between the supporting cylindrical part and the bent end of the gas tube, and a communication passage is formed in the rod guide to communicate the reservoir chamber with the outer space in front of the check valve lip. A thick outer peripheral seal made of rubber-like elastic material is provided on the outer diameter edge of the ring, and a connection made of rubber-like elastic material thinner than the outer peripheral seal is provided on the surface of the support ring that is caulked between the annular projection and the bent end. The structure is such that the parts are adhered to each other.

[Function] The first feature of the shock absorber having the above structure is that a thin elastic connecting part is attached to the surface of the base end of the oil seal support ring which is caulked between the supporting cylindrical part and the bent end. In other words, since the connecting part made of a rubber-like elastic material is wound around the caulking part, even if there is variation in caulking, the interposition of the connecting part made of the elastic material provides a sufficient sealing effect, and at the same time, the Since the connecting part made of elastic material is configured to have a thin wall, it is possible for a part of the connecting part made of elastic material to break due to the caulking load, causing local metal contact between the end surface of the supporting cylindrical part and the lower surface of the support ring. The second feature of this invention is that it always applies constant and strong contact pressure (holding force) and perfect sealing force to the axial contact between the check valve lip and the outer end surface (top surface) of the rod guide. It is.

Furthermore, since the outer circumferential seal portion is thicker than the connecting portion made of elastic material, good sealing performance at the caulking portion can be obtained.

[Example] Next, an example of the present invention will be described with reference to the drawings.

In FIG. 1, numeral 31 is an oil cylinder;
32 is a gas tube, 33 is a rod, 34 is a rod guide, 35 is an oil chamber, and 36 is a reservoir chamber, each of which functions in the same manner as in the conventional example.
The cross section of the oil seal, which is generally designated by the reference numeral 37, is approximately S.
A main lip 3 made of rubber-like elastic material and equipped with a garter spring 40 is attached to the inner diameter end of the support ring 38 which is shaped like a letter.
9 is baked, and the check valve lip 41 and the outer peripheral seal portion 42 are connected with the lower surface of the support ring 38 facing in the outer radial direction. This check valve lip 41 whose outer diameter surface is a pressure-receiving surface and an outer circumferential seal portion 42 which wraps around the outer diameter edge of the support ring 38 and extend around the upper surface of the support ring 38 are as shown in FIG. The support ring 38 is connected by a connecting part 43 formed into a thin wall with an actual size of about 0.2 to 0.3 mm (t), and the support ring 38 is caulked by the annular projection 44 of the rod guide 34 and the bent end 45 of the gas tube 32. At this time, the upper end surface of the annular projection 44 comes into contact with the connecting portion 43. Reference numeral 46 indicates an outer space in front of the check valve lip 41, and 47 indicates an inner space behind the check valve lip 41.
The rod guide 34 is provided with a communication passage 48 that communicates the former outer space 46 with the reservoir chamber 36.
A space 4 surrounded by the rod guide 34, guide tube 32, and support ring 38 on the outer periphery of the annular projection 44
9 is almost filled with an elastic material forming the outer peripheral seal portion 42. As shown in FIG. Further, behind the check valve lip 41 on the upper end surface of the rod guide 34, an annular tapered surface 50 is formed to receive the check valve lip 41 in order to prevent excessive deformation of the check valve lip 41.

In the shock absorber with the above configuration,
When the oil seal 37 is crimped between the rod guide 34 and the bent end 45 of the gas tube 32, the upper end surface of the annular projection 44 of the rod guide 34 comes into contact with the connecting portion 43 of the oil seal 37, as described above. The caulking load is usually around 1 ton, and when the part is caulked under this large load, the part of the connecting part 43 sandwiched between the annular protrusion 44 and the support ring 38, which becomes thin, will break locally. The members 38 and 44 are brought into direct contact (metallic contact). Therefore, the rod guide 34 and the oil seal 37 are always arranged at a constant distance, and the contact pressure of the check valve lip 41 that contacts the upper end surface of the rod guide 34 in the axial direction can be kept constant. Further, the space 49 on the outer peripheral side of this locally broken portion is filled with an elastic material forming the outer peripheral seal portion 42, so that a sufficient sealing effect can be achieved.

[Effects of the invention] As explained above, the shock absorber of the invention has the check valve lip of the oil seal and the rod guide facing each other in the axial direction, and also has a thin rubber-like elastic material on the surface of the oil seal support ring. It is characterized by having a bonded connection part.
The oil seal is strongly and completely sealed by the rod guide and gas tube, and
The contact pressure of the check valve lip against the rod guide is maintained constant, and since the outer peripheral seal part is thicker than the elastic material connection part, it is possible to provide sufficient sealing ability to the caulking part. The practical effects of this invention are extremely large.

[Brief explanation of the drawing]

Fig. 1 is a half-cut sectional view of the main part of a shock absorber according to an embodiment of the present invention, Fig. 2 is a half-cut sectional view of the same oil seal, and Fig. 3 is a half-cut sectional view of the main part of a shock absorber according to a conventional example. be. 31... Oil cylinder, 32... Gas tube, 33... Rod, 34... Rod guide, 3
5...Oil chamber, 36...Reservoir room, 37...
Oil seal, 38... Support ring, 39... Main lip, 41... Check valve lip, 42... Outer seal portion, 43... Connection portion, 44... Annular projection, 45... Bent end portion, 46 ...outer space, 47
...Inner space, 48...Communication path.

Claims (1)

[Scope of utility model registration request] An oil cylinder 31 is arranged on the outer periphery of the rod 33, a gas tube 32 is arranged on the outer periphery of the oil cylinder 31, and a rod guide 34 is provided at the axial end of the oil cinder 31 to slidably support the rod 33. , the rod guide 34
An annular projection 44 is provided on the axial end surface of the gas tube 32 , a bent end 45 is provided at the axial end of the gas tube 32 toward the inner circumferential direction, and an oil seal 37 is provided between the annular projection 44 and the bent end 45 . The support ring 38 is fixed by caulking, and the support ring 38 is provided with a main lip 39 that slides on the rod 33 and a check valve lip 41 that approaches and separates from the rod guide 34, and the rod guide 34 is provided with the oil cylinder 31 and the gas tube. 32, the check valve lip 41 is brought into contact with the axial end surface of the rod guide 34, A thick outer peripheral seal portion 42 made of a rubber-like elastic material is provided on the outer diameter edge of the support ring 38, and the support ring 3 is caulked between the annular projection 44 and the bent portion 45.
8. A shock absorber characterized in that a connecting portion made of a rubber-like elastic material is thinner than the outer circumferential seal portion 42 and is attached to the surface of the shock absorber 8.