JPS58211038A - Hydraulic damper - Google Patents

Abstract

PURPOSE:To make it possible to increase the freedom of a lower plate with respect to the specification of the damping characteristics of a damper, by making the inner diameter of the lower plate less than those of annular projections provided on the top surfaces of a piston and a bottom body. CONSTITUTION:A part of each lower plate 3g, 9g is projected into the inner diameter side of each annular projection 15, 16 by D<5>-D<4>=gamma, and serves as a deflection margine, so that the projected part is deflected together with the associated constant plate 3e, 9e and upper plate 3f, 9f upon a high speed movement of a piston rod 14 and constitutes a factor, similar to these constant and upper plates 3e, 9e, 3f, 9f, for determining the damping characteristics of the damper. Since the inner diameter D<4> of each lower plate 3g, 9g held between the constant plate 3e, 9e and the upper plate 3f, 9f, is made small, a passage defined by a notch 3d, 9d may be made long, thereby the generation of abnormal sound may be more efficiently prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides a hydraulic shock absorber in which the damping force increases in a substantially quadratic curve when the piston speed is low, and the damping force gradually increases when the piston speed exceeds a predetermined value. With regard to shock absorbers, by improving the constant plate and plate pulp in order to reduce the above-mentioned substantially quadratic rise damping characteristics, it is possible to increase the degree of freedom in specifying the damping force characteristics. This is what I did.

This type of hydraulic shock absorber is constructed as shown in FIG. That is, in the cylinder 1 filled with a working liquid such as oil, there is a damping force formed by a communication hole 2 on the upper and lower surfaces that allows limited circulation of the working liquid and a great pulp 8 that always partially closes the communication hole 2. A piston 6 equipped with a generating means 4 is slidably inserted into the cylinder 1 to corner the inside of the cylinder 1 into upper and lower chambers 6 and 7, and to allow limited flow of working fluid to the bottom of the cylinder 1. A bottom body 11 equipped with a damping force generating means 10 consisting of a communication hole 8 on the upper and lower surfaces and a root pulp 9 that always partially closes the communication hole 8 is attached, and a damping force generating means 10 is installed. The lower chamber 7 communicates with a reservoir chamber 13 for working fluid formed between the cylinder 1 and an outer cylinder 12 surrounding the cylinder 1, and a companion piston rod is fixed to the piston 5 from the top of the cylinder r1. 1
4 is formed by protruding. 15°16
17.18 is an annular projection 15.1 provided on the upper surface of the piston 5 and the upper surface of the bottom body 11.
A pulp retainer 19.20 holds the plate pulp 8 or 9 between the pulp retainer 17.18 and a spring 21.22 that lightly presses the great pulp 8, 9 against the annular protrusion 15.16 through the pulp retainer 17.18. 28.24 is the spring catch where the spring 19゜20 is attached.
are the liquid passages provided in the spring seats 21 and 22, and 25
．． 26 is a liquid passage hole provided in the pulp retainer 17, 18. And such a hydraulic shock absorber is a piston rod 14.
The end of the piston rod 14 is fixed to the spring of the vehicle body, and the cylinder 1 side is fixed to the bottom of the spring. A liquid passage 28 provided in the spring seat 21, a liquid passage hole 25 provided in the pulp retainer 17, a notch 3 m in the constant plate 8b, and a communication hole 2 in the piston 6.
The flow resistance when the working fluid flows into the lower chamber 7 and passes through the notch 8a generates a damping force that increases approximately quadratically as the piston speed increases, while the reservoir chamber 13
The working liquid inside easily pushes up the pulp retainer 18 and the great pulp 9 against the tin ring 20 to separate them from the annular protrusion 16 of the bottom body 11, and flows into the lower chamber 7 through the gap between the great pulp 9 and the bottom body 11. During the high speed extension stroke of the piston rod 14, the second
As shown in Figure A, bend the plate pulp 8 and
A working fluid flow path 27a is formed between the top pulp 8 and the pulp retainer 17 to gradually increase the damping force.

Also, during the low-speed compression stroke of the piston rod 14, the working fluid in the lower chamber 7 flows through the fluid passage hole provided in the spring seat 22.
), 4, ノ(?i[[a
The working fluid flows through the notch 9a of the hole 2B (constant gray) 9b into the reservoir chamber 1B, and due to the flow resistance when the working fluid passes through the notch 9 island, a damping force is generated in the same way as in the extension stroke, and the piston During the high-speed compression stroke of the rod 14, the plate pulp 9 is bent as shown in FIG. It looks like this. In addition, during the compression stroke of the piston rod 14, the working fluid in the lower chamber 7 easily pushes up the pulp retainer 17 and the plate pulp 8 against the spring 19 and separates them from the annular projection 16 of the piston 5. The upper and lower chambers 6 and 7 are communicated through a gap.

By the way, conventional root pulps 8 and 9 are shown in Figure 1 and Figure 2A.
1. As shown in Fig. 2B and Fig. 8, there is a notch 8 on the inner diameter side.
1...8a, 9m...9m (ring-shaped constant play) 8b, below 9b (1111), a ring-shaped play (4) with an inner diameter D4 smaller than the notch diameter ID) 8e
... 3o, 9e-H and 9c are overlapped, and when the piston rod 14 moves at low speed, the notches 8 & . . 3 m are formed.

A flow path 27a that passes through the flow path of the working liquid formed by 9a...9a, and is created by the flow path and the plate pulp being bent during high-speed movement.

27b, that is, from the inner periphery of the pulps 8 and 9, and a turbulent flow is formed near the lower surfaces of the plate pulps 3 and 9, causing abnormal noise.

Therefore, as shown in FIGS. 4 and 5, the plate pulps 8 and 9 have notches 8d...
A ring-shaped constant grate OE, 9e provided with 8d, 9d...9d is connected to a ring-shaped upper plate 8f, 9f having an inner diameter D3 that is smaller than the cutout diameter, and an inner diameter larger than the cutout diameter D1. D4 ring-shaped lower gray)8. ．． 9. By sandwiching and forming the flow path of the working liquid through the notches 8d...8d, 9d...9d, the outer periphery of the great pulp! 7 to eliminate the generation of vortices and prevent the generation of abnormal noise when the piston rod 14 moves at low speed, and when the piston rod 14 moves at high speed, the grate pulps 8 and 9 are bent. Pulp 8, 9 and pulp retainer 17.18
Working liquid flow paths 27m and 27b formed between the notches 8d and 8d, 9d and 9dK
J: #) The flow path of the working liquid that is formed is separated and the working liquid is allowed to flow from the inner and outer circumferences of the plate pulps 8 and 9 to prevent the generation of vortices and allow the piston rod 14 to move at high speed. Hydraulic shock absorbers were also developed to prevent abnormal noises caused by eddy currents (for example, Japanese Patent Publication No. 7782/1983).

However, conventionally, as shown in Figure 4, the lower play) 8g
, the inner diameter D4 of 9g is formed to be approximately the same diameter as the inner diameter 1) I of the annular projection 15.18.
, 9g did not bend even when the piston rod 14 moved at high speed, and therefore did not have any influence on the specifications of the damping force characteristics of the root pulps 8 and 9. As mentioned above, the reason why the inner diameter of the four ablate 8g + 9g is approximately the same as the inner diameter of the annular protrusion 15.18 is that in the conventional plate pulp 8.9, the inner diameter of the four ablate 8g + 9g
Company G is used exclusively for the purpose of preventing the annular projections 15, 16 from being worn out by the working fluid flowing through the notches 8d-1, 8d, 9d...9d, and achieves this purpose. For this purpose, lower plate 8, .
This is because it is sufficient to form 9g into a ring shape having approximately the same diameter and width as the annular protrusion 15.16.

In addition to the wear prevention function of the annular projections 15 and 16, the present invention has an influence on the damping force characteristic determination of the plate valves 8 and 9 (a function involved in the damping force characteristic determination). and constant play) B@, 9@ notch 8d...8d.

9d...9d and upper play) 8f, the lower surface of 9f, and lower grade 8. ．． The purpose of this is to make the flow path formed by the upper surface of 9g as long as possible to promote rectification of the fluid and to more effectively prevent the generation of abnormal noise. The gist of the structure is that the inner diameter D4 of the busy lower plate 8gp9g is made smaller than the inner diameter D1 of the annular projection 15.16 as shown in the drawings from FIG. 6 onwards. Lower plate 8g.

Except that the inner diameter D4 of 9g is smaller than the inner diameter D1 of the annular projection 15.16, it is exactly the same as the conventional example shown in FIGS. 9
d...9d is set as the next ring-shaped constant grating 8
. , 9. is the notch diameter D! The ring-shaped upper plate 81.91 has an inner diameter D3 smaller than the notch diameter D! 8. ．． 9.
It is formed by clamping it with.

Subordinate CU77 race) 8 g, 9 gt! DI-
84 = afe protruding to the inner diameter side of the annular protrusion 15, 16, the protruding portion is not a so-called bending allowance, the piston rod 14
Constant Great 8・, 9e4p when moving at high speed
7/<11/-) 8f, 9f and these constant gray) 8e, 9e and upper-) 8f,
Similarly to 9f, the lower grating 8 is a factor in determining the damping force characteristics of the plate valve 8.9, and is also clamped between the constant grating 8, 9e and the upper play (8f, 9f). Since the notches 8d...8d and 9d...9d are made smaller, the flow paths can be formed longer, and the generation of abnormal noise can be more effectively prevented. Note that parts that are the same as those in the prior art are designated by the same reference numerals and redundant explanations will be omitted.

As explained above, the present invention generates a damping force by forming a communication hole on the upper and lower surfaces that allows limited circulation of the working liquid in a cylinder filled with the working liquid, and a plate valve that constantly closes the communicating hole. A piston equipped with means is slidably inserted into the cylinder, and the inside of the cylinder is lifted up.

A bottom body is provided at the bottom of the cylinder, which is separated from the lower chamber and is equipped with a damping force generating means consisting of a communication hole on the upper and lower surfaces and a plate valve that always closes the communication hole, which allows limited flow of the working fluid. mounting, communicating the lower chamber through the communication hole of the bottom body with a reservoir chamber for a working fluid formed between a cylinder and an outer cylinder surrounding the cylinder, and connecting the piston from the top of the cylinder. In a hydraulic shock absorber which is fixed and has a protruding piston rond, the plate valve is formed by a ring-shaped constant plate having a notch on the outer diameter side, and a ring-shaped upper part having an inner diameter smaller than the notch diameter of the constant plate. The plate and the ring-shaped lower grating 7 are formed to have an inner diameter larger than the notch diameter of the constant grate and sandwich the constant grate between the upper plate, and the inner diameter of the lower grate is The annular protrusions on the top surface of the piston and bottom body are also made to have a small diameter, so the lower plate not only has the function of preventing wear of the annular protrusions and the generation of abnormal noise, but also has the function of contributing to the determination of damping force characteristics. This has the advantageous practical effect of increasing the degree of freedom in specifying the damping force characteristics of plate pulp.

[Brief explanation of the drawing]

Figure 1 is a sectional view of a conventional hydraulic shock absorber, Figure 2 A and 2
Figure B is a cross-sectional view of the plate pulp in a bent state.
The figure is a plan view of the constant grate and lower grate with notches on the inner diameter side that make up the plate pulp of the hydraulic shock absorber shown in Fig. 1, Fig. 2 A1, Fig. 2 B, and Fig. 4 is a plan view of the constant grate and lower grate with notches on the inner diameter side. A cross-sectional view of a conventional hydraulic shock absorber using a constant plate with a notch. 6 is a sectional view of the hydraulic shock absorber of the present invention; FIG. 7 is an enlarged view of the piston portion of FIG. 6; FIG. 8 is an enlarged view of the bottom body portion of the same; FIG. 9 is a sectional view taken along the line IX-IX in FIG. 7. 1...Cylinder, 2...Communication hole, 3...Grate pal 7", 8d...Notch, 8e...Constant grade, 8f...Upper grade, 8g...Lower grade, 4... Damping force generating means, 5... Piston, 6, 7... Upper. Lower chamber, 8... Communication hole, 9... Plate no.
d...Notch, 9...Constant great, 9f
...Uppal-Fs9g...Lower Great, 10.
... damping force generating means, 11 ... bottom body, 12.
...Outer cylinder, 18...IJ f-bar chamber, 14...Piston portion door, 175.16...Annular projection. Figure 1

Claims (1)

[Claims] (1) A piston is provided with a damping force generating means consisting of a communication hole on the upper and lower surfaces, which allows limited flow of the working liquid, and a plate valve that constantly closes the communicating hole, in a cylinder filled with working liquid. a communication hole on the upper and lower surfaces that is slidably inserted to separate the inside of the cylinder into upper and lower chambers, and also at the bottom of the cylinder that allows limited flow of the working fluid;
A bottom body equipped with a damping force generating means consisting of a plate valve that constantly closes the cough communication hole is attached, and the space between the lower chamber and the cylinder and the outer cylinder surrounding the cylinder is provided through the communication hole of the core bottom body. In the hydraulic shock absorber, the plate valve is provided with a notch on the outer diameter side in the hydraulic shock absorber, which communicates with a reservoir chamber for working fluid formed in the cylinder, and has a piston rod fixed to the piston protrude from the top of the cylinder. a ring-shaped constant root, a ring-shaped upper plate having an inner diameter smaller than the notch diameter of the constant plate, and a ring-shaped upper plate having an inner diameter larger than the notch diameter of the constant slate, which is connected to the upper plate. It consists of a ring-shaped lower plate sandwiching the above-mentioned Constant) ';'l/-) between them, and the inner diameter of the nuclear lower plate is set on the upper surface of the piston and bottom body so that it is smaller than the skin annular projection. A hydraulic shock absorber characterized by being formed with a small diameter.