JPS60517Y2 - hydraulic shock absorber - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a hydraulic shock absorber in which a piston to which a piston rod is integrally attached is slidably housed in a cylinder filled with hydraulic oil.

Conventionally, the damping force characteristics of a hydraulic shock absorber using only a disc valve can be plotted from line C-D to line C-E or C-F in Figure 5.
In order to change it to a line, (1) a method that constricts the oil passage of the piston, (11) a method that constricts the oil passage of the disc valve that forms the oil passage, and (iii) a method that constricts the oil passage of the disc valve that formed the oil passage.
A method of using a retainer having an oil passage and a seat surface on the piston seat surface and constricting the oil passage of this retainer has been adopted.

However, the above method (1) has the disadvantage that there are a large number of types of pistons, resulting in high cost.

In addition, in the case of (11) above, when using a piston having two groups of oil passages, it is necessary to align the oil passages of the disc valve and the oil passage of the piston with each other in order to communicate with each other. In addition, even if alignment is carried out, there will be misalignment when tightening the nut, and in extreme cases, misalignment will also occur during operation.

Furthermore, in the case of (iii), since the retainer also serves as a seat surface, it needs to have an appropriate thickness, making it impossible to use a thin plate like valve material, resulting in high costs, and the overall length of the valve structure being large. This resulted in the disadvantage that

The purpose of the present invention is to eliminate the drawbacks of the above-mentioned prior art,
It is an object of the present invention to provide a hydraulic shock absorber that has a simple and compact structure, is easy to assemble, and can easily obtain necessary damping force characteristics.

The structure of this invention is 1. A piston to which a piston rod is integrally attached is slidably housed in a cylinder filled with hydraulic oil, the piston separates the inside of the cylinder into two chambers, and the two chambers are separated between both end surfaces of the piston. two groups of oil passages communicating with each other are formed, a t6-seat surface is formed from a protrusion shaped to surround the openings of the group of oil passages on one end surface of the piston, and a t6-seat surface is formed on the other end surface of the piston. A seat surface formed from a projection having a shape that surrounds the opening of the oil passage of the other group is formed, a disc valve made of a flexible member is seated on each of the seat surfaces, and a small portion of the both seat surfaces is seated. This hydraulic shock absorber is characterized in that a retainer fitted to one of the retainers is provided with a cutout groove that overlaps with an opening of the oil passage located outside the seat surface.

Hereinafter, one embodiment of the present invention will be described based on the drawings.

A small diameter portion 1a is formed at the tip of the piston rod 1,
A threaded portion 1b is formed at the end of this small diameter portion 1a.

Washers 2.2' and 3.3' are attached to the small diameter portion 1a.
The disc valves 4, 4', retainer 5, and piston 6 are positioned so as to be sandwiched between them, and these members are connected to the piston rod 1 by a nut 7 that is screwed into the threaded part 1b formed in the small diameter part 1a. It is integrated with.

The piston 6 has two groups of oil passages 6a, 6a and 6b, 6b.
are formed, and these oil passages are located radially.

One end surface 6' of the piston 6 has a group of oil passages 6a,
A seat surface 8 is formed in a strip shape surrounding the oil passages 6a, and the other end surface 6'' of the piston 6 is provided with a seat surface 8 formed from a protruding shape surrounding the oil passages 6b, 6b of the other groups. 8' is formed.

Disc valves 4 and 4' made of flexible members are seated on these seat surfaces 8 and 8', respectively, and in an inoperative state, the disc valve 4 is attached to one end surface 6 of the piston 6.
The openings of the oil passages 6a, 6a on the side 6'' are substantially closed, and the disc valve 4' similarly closes the openings of the oil passages 6a, 6a on the other end face 6'' side.

The opening of 6b is substantially closed.

The retainer 5 also has an O-shaped opening 5a in its center that fits into the seat surface 8, and has notched grooves 5 on both sides thereof.
b, forming 5b.

The retainer 5 is mounted on one end surface 6' of the piston 6 with the opening 5a fitting into the seat surface 8 and the notch grooves 5b overlapping the oil passages 6b, 6b, respectively.

Note that the reason why the washers 3 and 3' are smaller in diameter than the washers 2 and 2' is so as not to hinder the deflection of the disc valves 4 and 4'.

The action will be explained below.

When the piston-piston rod assembly shown in FIG. 1 is accommodated in a cylinder (not shown) filled with hydraulic oil and the piston rod 1 is moved in the X direction, the damping force is reduced by the fixed orifice (not shown) as shown in FIG. shows the B-C characteristics of

If the piston speed increases further from this state,
The hydraulic oil passes from the A chamber in the cylinder to the notched grooves 5b, 5b of the retainer 5, and the oil passages 6b, 6b, pressurizes the disc valve 4', and the disc valve 4' opens.

As the moving speed of the piston 6 increases, the notch groove 5b.

The throttling effect of 5b increases relatively, thereby increasing the damping force.

Also, when the piston 6 moves back in the X' direction, B
The hydraulic oil in the room opens the disc valve 4 through the oil passages 6a, 6a, and flows into the A room.

Therefore, if the retainer 5 is fitted not only to the seat surface 8 but also to the seat surface 8', the same damping force characteristics can be obtained during the forward movement of the piston 6 in the X' direction as when moving in the X direction. can get.

Furthermore, if a suction valve is inserted in place of the disc valves 4, 4', a damping force will be generated only when the heavy stone 6 moves in the X direction.

As explained above, according to the hydraulic shock absorber of the present invention, the piston is of one type and has a simple structure, and both end faces are symmetrical at positions rotated by 90 degrees relative to each other, so that the piston is symmetrical. This has the advantage of good assembly performance.

In addition, since the opening of the retainer is shaped to fit into the seat surface, it is easy to overlap the notch groove and the oil passage, and at the same time it also functions as a rotation stopper, making assembly work easier. arise.

Further, by changing the size of the notch groove in the retainer, arbitrary damping force characteristics can be obtained, and since the retainer can be press-molded, it is inexpensive.

Furthermore, since the overall length of the valve structure remains the same regardless of whether a retainer is used, this has a significant effect on reducing the size of the hydraulic shock absorber.

[Brief explanation of the drawing]

Figure 1 is a sectional view of the main parts of the hydraulic shock absorber of the present invention taken along the line C-C' in Figure 2, Figure 2 is a front view of the end face of the piston on the A chamber side, and Figure 3 is a front view of the piston on the B chamber side. FIG. 4 is a front view of the end face, FIG. 4 is a front view of the retainer, and FIG. 5 is a damping force characteristic diagram. 1... Piston rod, 2, 2', 3, 3'.
...Washer, 4.4'...Disc valve, 5...Retainer, oil passage, 6...Piston, 6a, 6a...・One group 6b, 6b...Oil passages of other groups, 7...
Nut, 8, 8'... Seat surface, 5b...
...Notch groove.

Claims (1)

[Scope of utility model registration request] A piston to which a piston rod is integrally attached is slidably housed in a cylinder filled with hydraulic oil, the inside of the cylinder is divided into two chambers by the piston, and the two chambers are separated between both end surfaces of the piston. In order to form two groups of oil passages through which the piston passes, a seat surface consisting of a protrusion having a shape that surrounds the openings of the group of oil passages is formed on one end surface of the piston, and a seat surface consisting of a protrusion that surrounds the openings of the oil passages of the group is formed on the other end surface of the piston. A seat surface is formed by a protrusion having a shape that surrounds the opening of the oil passage of the other group, and a disc valve made of a flexible member is seated on each of the seat surfaces, and at least one of the seat surfaces is seated. A hydraulic shock absorber characterized in that a notched groove is formed in the fitted retainer to overlap with an opening of the oil passage located outside the seat surface p.