JPS6336188Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a sealing device for a hydraulic shock absorber, and more particularly to a sealing device for a hydraulic shock absorber that simplifies the packing seal and shortens the basic length of the hydraulic shock absorber.

This type of conventional standard shock absorber has a bearing 3 fixed to the upper ends of an outer tube 1 and an inner tube 2, as shown in FIG.
A piston rod 4 slidably inserted into the inner tube 2 passes through the bearing 3 and projects to the outside.

A packing case 5 is provided above the bearing 3, and a piece-shaped packing 6 is disposed within the packing case 5. The inner peripheral seal lip 7 of the packing 6 slides into contact with the outer periphery of the piston rod 4 with an arbitrary tightening margin. This prevents internal oil from leaking and dust from entering from the outside.

A packing plate 8 and a spring 9 are interposed between the packing 6 and the bearing 3, and these springs 9 and packing plate 8 are connected to the seal lip 7.
The gasket 6 is pushed upward to improve the sealing performance.

However, the above sealing device has the following problems due to the presence of the packing plate 8 and the spring 9. Since the number of parts is large, the ease of assembly is poor, and a relatively large space is required to assemble these parts, the basic length of the shock absorber itself becomes long, and the sealing performance of the seal lip 7 depends on the tension of the spring 9 and the inside of the cylinder. It is unstable because it depends on internal pressure.

Therefore, the purpose of the present invention is to provide a sealing device for a hydraulic shock absorber that has a small number of parts, has a simple structure, is easy to assemble, can shorten the basic length of the shock absorber, and can improve sealing performance. It is to provide.

Embodiments of the present invention will be described below with reference to the drawings.

A preferred embodiment of the invention is shown in FIG. That is, the shock absorber 10 has an inner tube 2 coaxial with the outer tube 1.
A bearing 11 is fixed to the upper ends of the outer tube 1 and the inner tube 2, and the piston rod 4, which is slidably inserted into the inner tube 2 via a piston, slides on the inner periphery of the bearing 11. It penetrates freely and protrudes to the outside.

A packing case 12 fixed between the outer tube 1 and the bearing 11 stands above the bearing 11. A top-shaped packing 13 is disposed inside the packing case 12, and an inner circumferential seal lip 14 of the top-shaped packing 13 is The seal lip 14 slides into contact with the outer periphery of the piston rod 4 with an arbitrary tightness, and scrapes off the oil film adhering to the outer periphery of the piston rod 4 to prevent oil from leaking to the outside, and also prevents dust from entering from the outside. is prevented.

A reservoir chamber 15 containing oil and gas is defined between the outer tube 1 and the inner tube 2, and an oil chamber 16 with a relatively small space is defined between the gasket 13 and the bearing 11. The oil is in the groove 24 of the bearing 11.
The oil is returned to the reservoir chamber 15 through a vertical oil hole 18.

The outer periphery of the packing 13 is integrally formed with the inner periphery of the packing case 12 by baking to ensure the airtightness of the baking surface 17, in other words, sealing performance, and the need for a packing plate and spring as in the past can be omitted. ing. Furthermore, by omitting the packing plate and spring, the space of the oil chamber 16 can be made as small as possible, thereby shortening the basic length of the shock absorber 10 itself, and also allowing the piston rod 4 to have a sufficient stroke. .

Also, the seal lip 1 for the piston rod 4
To maintain the sealing performance in step 4, use packing case 1.
This is achieved by forming the upper end surface of the seal lip 2 into a conical shape and by increasing the number of stages of the seal lip 14 to four or more stages.

According to the present invention, there are the following effects.

Since the outer circumference of the seal is integrally baked into the inner circumference of the seal case, there is no need for springs or seal plates as in the past, the number of parts is small, the structure can be simplified, and the ease of assembly and assembling can be greatly improved. At the same time, it is possible to ensure airtightness on the baking surface.

Similarly, since there is no spring or packing plate, the space in the oil chamber below the packing can be reduced, which allows the basic length of the shock absorber itself to be shortened.

Since there are four or more stages of seal lips, the seal lips complement each other to prevent tilting and improve sealing performance. Furthermore, since there are many seal lips, the interference with the seal lip can be reduced, so the friction of the piston rod 4 with respect to the seal lip is small, and the sliding performance of the piston rod 4 can be improved.

Since the upper end surface of the packing case is formed into a conical shape, a component of the repulsive force based on the radial interference on the packing acts as a component force downward in the center direction on the seal lip, so that the oil film against the oil film on the piston rod is It is possible to increase the wiping effect and ensure sealing performance.

[Brief explanation of the drawing]

Figure 1 is a vertical side view of a conventional sealing device, Figure 2 is a vertical side view of a conventional sealing device.
The figure is a longitudinal sectional side view of a sealing device according to one embodiment of the present invention. 12... Patsukin case, 13... Patsukin,
14...Seal lip.

Claims (1)

[Scope of utility model registration request] The outer periphery of the packing is integrally baked and molded in advance on the inner periphery of the packing case having a conical upper end face to achieve an outer seal, and the inner periphery seal lip of the packing with respect to the piston rod has an increased number of stages to four or more stages. Hydraulic buffer sealing device.