JPH0743506Y2 - Hydraulic shock absorber - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION << Industrial Application Field >> The present invention relates to a rod guide structure for a hydraulic shock absorber.

<< Prior Art >> Conventionally, as a rod guide structure of this type of hydraulic shock absorber, for example, one described in Japanese Utility Model Laid-Open No. 55-157140 is known.

This product is equipped with a rod guide on the upper end of the cylinder, and slidably supports the piston rod on the rod guide, so that the working fluid or gas leaked from between the rod guide and the piston rod can be transferred between the cylinder and the reservoir tube. The reservoir is formed to recirculate through a passage hole provided in the rod guide to prevent the rod seal from leaking out of the hydraulic shock absorber.

<Problems to be solved by the invention> However, in the conventional device having such a structure, the rod guide member is manufactured by sintering, and a passage hole for returning the working fluid or gas to the reservoir chamber is provided. In order to perform molding, a very complicated molding die is required, or when machining is performed after sintering the rod guide, post-processing such as drilling is required, which causes a problem of increased manufacturing cost. It was

An object of the present invention is to provide a hydraulic shock absorber provided with an improved rod guide having a simple structure in view of the conventional problems.

<Means for Solving the Problem> In order to achieve the above-mentioned object, the present invention forms an outflow passage for connecting a cylinder chamber of a rod guide of a hydraulic shock absorber with a reservoir chamber at a side portion of a square plate member. It is characterized by doing.

<Operation> In the rod guide of the hydraulic shock absorber having the above structure, when the side portions of the rectangular plate member are formed, the side portions are formed at different positions in the axial direction. Formed and does not require any special post-processing for the outflow passage.

<< Embodiment >> An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is an overall cross-sectional view of a hydraulic shock absorber having a rod guide according to an embodiment of the present invention, in which 10 is a cylinder constituting the main body of the hydraulic shock absorber, and 20 is a retractable member in the cylinder 10. A piston rod 30 to which a piston described later is attached to the stud portion 21 having a thin tip is a reservoir tube which is arranged around the cylinder 10 and forms a reservoir chamber 31 with the cylinder 10.

Reference numeral 40 denotes a piston attached to the stud portion of the piston rod 20, which is slidably fitted to the inner peripheral surface of the cylinder through a seal band 41 provided on the outer peripheral portion so that the cylinder chamber is located in the upper liquid chamber and the lower portion. It is divided into a liquid chamber. This piston
The extension side passage 42 that connects the upper liquid chamber and the lower liquid chamber is provided with 40.
A compression side passage 43 is provided, and an expansion side disc valve 44 and a compression side disc valve 45 are provided at one opening of each of the passages so as to close each passage. Incidentally, 46
Is a rebound stopper, 47 is a valve stopper, 48 is a washer arranged on the rear surface of the expansion side disc valve 44 and the compression side disc valve 45, and these members are fitted into the stud portion 21 of the piston rod 20, and Set nut
Fixed by 49.

Reference numeral 50 designates a rod guide which slidably guides the piston rod 20 through a guide bush 51 provided on the inner periphery and whose outer periphery is fitted to the upper end of the cylinder 10. As shown in detail in FIG. Is formed by deep drawing, and has a cylindrical guide bush press-fitting portion 52, a rebound rubber fixing portion 53 continuously provided to the guide bush press-fitting portion 52, and a diameter expanded from the rebound rubber fixing portion 53. A cylinder tube press-fitting portion 54 formed in a cylindrical shape, a flat surface continuous with the cylinder tube press-fitting portion 54, and an upper surface in the drawing serves as a check seal contact surface 55 and a lower surface in the drawing serves as a cylinder end contact portion 56. A flange portion 57 and a rod seal abutting portion 58 which is continuous with the flange portion 57 and is provided in a planar shape. The rod seal abutting portion is formed with a notched outflow passage 59. ing.

Reference numeral 60 denotes a rod seal including a disc-shaped core metal 61 and each seal portion integrally formed by baking the core metal 61,
The seal member is in contact with the outer periphery of the piston rod 20 to prevent the hydraulic fluid and gas from leaking out of the shock absorber between them, and the seal member elastically contacts the check seal contact surface 55 of the rod guide 50. Check seal 63 that allows the flow of fluid from inside to outside and blocks the flow in the opposite direction
And an outer peripheral seal 64 that prevents the working fluid and the gas from leaking from between the reservoir tube 30 and the core metal 61 by coming into contact with the inner surface of the bent end portion of the reservoir tube 30 during assembly.

70 is a guide bush press-fitting portion 52 of the rod guide 50.
The rebound rubber fixed to the rebound rubber fixing groove 53 by fitting to the outer periphery of the rebound rubber is shown, and the rebound stroke is regulated by contacting the rebound stopper 46 at the lower side in the figure.

Then, the cylinder 10 is inserted into the reservoir tube 30, the piston 40 and the piston rod 20 are inserted into the cylinder 10, the upper end of the cylinder 10 is closed by a rod guide 60, and the upper end of the reservoir tube 30 is closed by a rod seal 60. After that, the upper end of the reservoir tube is swaged to form a hydraulic shock absorber.

The operation of the embodiment of the present invention having the above configuration will be described below.

First, the operation of the hydraulic buffer will be described.

When the piston 40 rises in the figure during the expansion side operation, the hydraulic fluid in the upper liquid chamber reaches the expansion side disk valve 44 via the expansion side passage 42 and pushes the expansion side disk valve 44 to generate the expansion side damping force. While flowing into the lower liquid chamber.

During this extension side operation, the working liquid in the upper liquid chamber, including some gas, passes through the minute gap between the piston rod 20 and the guide bush 51 and reaches the space formed by the rod seal 60 and the rod guide 50. , Lubricates the oil seal 62 and pushes open the check seal 63 to open the reservoir 31 via the outflow passage 59.
To help the gas accumulated in the upper part of the cylinder 10 flow out to the reservoir 31.

Further, when the piston 40 moves downward in the drawing, the hydraulic fluid in the lower fluid chamber passes through the pressure side passage 43 and the pressure side disc valve.
When it reaches 45, the pressure side disc valve 45 is pushed open to generate a pressure side damping force and flow into the upper liquid chamber.

At the time of this pressure side operation, the pressure in the upper liquid chamber drops, and the action of sucking gas from the reservoir chamber 31 occurs, but since the check seal 63 is arranged on the passage, the gas from the reservoir chamber 31 Prevent inhalation.

Next, in order to explain the manufacturing process of the rod guide 50 of the present embodiment, when the rectangular (square in the example) plate material shown in FIG. 4 is sequentially deep-drawn, the corner ABCD of the square member becomes After processing, it projects in the axial direction and in the radial direction, and each side EFGH part is in a state of retracting in the axial direction after processing and radial direction. Therefore, this causes the rod guide 50 to
In the state after processing shown in the figure, the rod seal contact portion 58 is formed in a state of protruding in the radial direction, and the portion corresponding to each side portion EFGH portion becomes a portion retracted in the axial direction, so that the hydraulic fluid and It will be formed in the gas outflow passage 59. Therefore, since it is only necessary to use a square plate material as the material shape, it is possible to form the outflow passage 59 without requiring post-processing.

In the above-mentioned embodiment, the material is a square plate material, but if it is a square plate material, it may be a triangular plate or a pentagonal plate material.
Although it may be a hexagonal type, the square type shown in the drawing is the most preferable in view of the planing. Further, in the illustrated example, each corner is chamfered. However, the degree of chamfering is determined in consideration of the inversely proportional relationship between the groove depth of the outflow passage 59 and the degree of chamfering during molding. And is not necessary when the groove depth is deep.

<< Advantages of the Invention >> As described above, according to the rod guide of the hydraulic shock absorber of the present invention, since the outflow passage that connects the cylinder chamber and the reservoir chamber is formed by the side portion of the square plate member, When the sides of the mold plate material are formed, the sides are formed at different positions in the axial direction, and the outflow passage is formed at the same time when the rod guide is formed, so that the outflow passage can be obtained without special post-processing. Therefore, the processing is simplified, and the manufacturing cost can be reduced.

In addition, since the material plate material can be formed into a square shape, the yield of the material can be improved, and the effect that it can be manufactured at low cost is also achieved.

[Brief description of drawings]

1 is an overall sectional view showing an embodiment of a rod guide of a hydraulic shock absorber of the present invention, FIG. 2 is a detailed sectional view of the rod guide shown in FIG. 1, and FIG. 3 is a sectional view of FIG. And FIG. 4 is a plan view of the material of the rod guide of FIG. 10 ... Cylinder, 20 ... Piston rod, 30 ... Reservoir tube, 40 ... Piston, 50 ... Rod guide, 59 ... Outflow passage, 60 ... Rod seal.

Front page continuation (72) Inventor Masayo Kushida 1370 Onna, Atsugi City, Kanagawa Prefecture Atsugi Motor Parts Co., Ltd. (56) References: Kaihei 1-94639 (JP, U) U)

Claims (1)

[Scope of utility model registration request] 1. A hydraulic shock absorber, characterized in that an outflow passage communicating with a cylinder chamber of a rod guide of the hydraulic shock absorber and a reservoir chamber is formed by a side portion of a rectangular plate member.