JPH062044Y2 - Hydraulic shock absorber rod guide mechanism - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial field of application) The present invention relates to a rod guide mechanism for a hydraulic shock absorber.

(Prior Art) In a hydraulic shock absorber used in an automobile or the like, a rod guide mechanism is provided in an upper end portion of an outer tube in order to guide a piston rod inserted in the outer tube and to perform an oil seal.

As shown in FIG. 3, the rod guide mechanism includes:
A rod guide 52 is fitted in the upper end portion of the outer tube 51, an inner tube 53 is fitted in the outer circumference of the rod guide 52, and the tip end portion of the rod guide 52 is slidable in the inner tube 53. A rebound seat 55 provided on the outer periphery of the piston rod 54, through which a piston rod 54 equipped with a piston (not shown)
A rebound rubber 56 is fitted on the upper surface of the.

An O-ring 57 is provided on the outer periphery of the upper end of the rod guide 52.
To seal the space between the outer tube 51 and the outer tube 51.
Is fitted, and an oil seal 59, which is in sliding contact with the outer circumference of the piston rod 54, is held by this oil seal case 58, a cap 60 is fixed to the end portion of the outer tube 51, and the working oil in the outer tube 53 leaks to the outside. It is sealed to prevent it.

(Problems to be solved by the invention) However, in the rod guide mechanism of the hydraulic shock absorber described above, since the rod guide, the rebound rubber, and the oil seal case are individually manufactured and incorporated, the number of parts and the number of manufacturing steps are reduced. Many are poor in productivity. Further, when these parts are made of metal, the hydraulic shock absorber becomes heavy.

(Means for Solving the Problems) In order to solve the above problems, the present invention provides a double tube type including an outer tube and an inner tube provided with a rod guide mechanism for guiding the piston rod in the upper end portion of the outer tube. In the hydraulic shock absorber, a seal case portion that holds an oil seal that slidably contacts the outer peripheral surface of the piston rod, a rod guide portion that slidably contacts the outer peripheral surface of the piston rod, and a rebound rubber portion that a rebound seat fitted to the piston rod abuts. Was integrally molded with resin, and a metal ring was embedded in a portion of the rod guide member that abuts the upper end of the inner tube.

(Operation) Since the metal ring embedded in the portion of the rod guide member that abuts the upper end of the inner tube protects the portion of the resin rod guide member that receives the upper end of the inner tube, the strength problem is solved. When the seal case portion, the rod guide portion, and the rebound rubber are integrally formed of a lightweight resin material, the number of parts is reduced and the weight is reduced without impairing the durability.

(Embodiment) An embodiment of the present invention will be described below with reference to the accompanying drawings.

FIG. 1 is a sectional view showing a hydraulic shock absorber having a rod guide mechanism according to the present invention, and FIG. 2 is a perspective view of a bush of the rod guide mechanism.

In this hydraulic shock absorber 1, an inner tube 3 is planted in an outer tube 2, a piston rod 4 is inserted into the inner tube 3 from above, and a rebound seat 5 is fitted in an intermediate portion of the piston rod 4. Further, a piston 6 which is in sliding contact with the inner peripheral surface of the inner tube 3 is attached to the tip end portion of the piston rod 4, and a valve mechanism 7 for generating a damping force is attached to the piston 6.

A rod guide member 10 for guiding the piston rod 4 and performing an oil seal is provided in the upper end portion of the outer tube 2.
Is fitted. The rod guide member 10 is fitted to the seal case portion 11 that holds an oil seal slidably contacting the outer peripheral surface of the piston rod 4, the rod guide portion 12 slidably contacting the outer peripheral surface of the piston rod 4, and the bound seat. Rebound rubber part 1 with which 5 abuts
3 and 3 are integrally formed with resin (for example, nylon with glass material).

An oil seal 14 slidingly contacting the outer peripheral surface of the piston rod 4 is provided in the seal case portion 11 of the rod guide member 10.
Holding

An O-ring 15 is fitted on the outer peripheral surface of the rod guide portion 12, an oil hole 16 is formed in the middle portion in the axial direction, and an upper end portion of the inner tube 3 is fitted on the lower outer peripheral surface. A metal ring (material SP) 17 having a pressure receiving area larger than the upper end pressure receiving area is provided at the portion where the upper end of 3 abuts.
Is embedded, and the metal ring 17 reinforces the rod guide member 10 to prevent deformation.

Further, a bush 18 that is in sliding contact with the outer peripheral surface of the piston rod 4 is fitted on the inner peripheral surface of the rod guide portion 12 of the rod guide member 10. As shown in FIG. 2, the bush 18 has a convex portion 18a and a concave portion 18b at both ends of a strip-shaped plate material.
As a clinch type that engages with concave and convex to regulate circumferential and axial deformation, it is possible to obtain highly accurate dimensions without press fitting, and the resin flows out to the inner peripheral side through the bush cut. I try not to.

The rebound rubber portion 13 of the rod guide member 10 functions as a rebound rubber and also has an effect of preventing the bush 18 from coming off due to back pressure.
The pressure receiving area of is reduced.

The end plate 19 (material S is formed between the upper surface of the rod guide member 10 and the inner upper surface of the outer tube 2).
P) is interposed to prevent deformation of the rod guide member 10.

A cap 20 is fitted on the upper end of the outer tube 2 and a cap 21 is welded on the lower end.

Since the hydraulic shock absorber 1 is assembled as described above, when the hydraulic shock absorber 1 is assembled, only by fitting the rod guide member 10 into the upper end portion of the outer tube 2, a seal for holding the oil seal 14 which is in sliding contact with the outer peripheral surface of the piston rod 4. The case portion, the rod guide portion that slidably contacts the outer peripheral surface of the piston rod 4, and the rebound rubber portion that the rebound seat 5 fitted to the piston rod 4 contact can be easily assembled.

(Effect of the Invention) As described above, according to the present invention, by providing the rod guide member in which the oil seal case portion, the rod guide portion, and the rebound rubber portion are integrally formed of resin, a component of the rod guide mechanism is provided. The number of points is reduced, the rod guide mechanism is easily manufactured, and productivity is improved.
Further, the weight of the hydraulic shock absorber can be reduced without impairing the durability.

[Brief description of drawings]

FIG. 1 is a sectional view showing a hydraulic shock absorber provided with a rod guide mechanism according to the present invention, FIG. 2 is a perspective view of a bush of the rod guide mechanism, and FIG. 3 is a rod guide mechanism of a conventional hydraulic shock absorber. FIG. In the drawings, 1 is a hydraulic shock absorber, 2 is an outer tube, 3
Is an inner tube, 4 is a piston rod, 6 is a piston, 10 is a rod guide member, 11 is an oil seal case part, 12 is a rod guide part, 13 is a rebound seat part, 14 is an oil seal case, 17 is a metal ring, 1
8 is a bush.

Claims (1)

[Scope of utility model registration request] 1. A double-tube type hydraulic shock absorber comprising an outer tube and an inner tube having a rod guide mechanism for guiding a piston rod in an upper end portion of the outer tube, wherein an oil seal slidably contacting an outer peripheral surface of the piston rod is provided. A rod guide member integrally formed of a resin is provided with a seal case portion for holding, a rod guide portion slidably contacting the outer peripheral surface of the piston rod, and a rebound rubber portion with which a rebound seat fitted on the piston rod abuts. A rod guide mechanism for a hydraulic shock absorber, wherein a metal ring is embedded in a portion of the guide member that abuts the upper end of the inner tube.