JP2525265Y2 - Piston valve structure in hydraulic shock absorber - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a piston valve structure in a hydraulic shock absorber.

(Prior Art) As a piston valve structure in a conventional hydraulic shock absorber, for example, the one described in Japanese Utility Model Laid-Open No. 63-178646 is known.

In such a conventional structure, a piston that defines the inside of a cylinder filled with fluid into two chambers is formed by a single member, and the piston has a parallel expansion side flow path and a pressure side flow that communicate the two chambers. The path and the extension-side seat surface and the compression-side seat surface with which the damping valve abuts were respectively formed.

Further, a groove was formed on the outer periphery of the piston, and a piston ring was fitted in this groove.

(Problems to be Solved by the Invention) However, in such a conventional piston valve structure, as described above, since the piston is formed by a single member, the two parallel pistons communicating the two chambers are formed. When the flow path is formed, it is necessary to perform processing for forming the flow path with a drill or the like, and there is a problem that the processing is complicated.

In particular, when forming the expansion side flow path and the compression side flow path in parallel on the piston, it is necessary to form the diagonal direction from the inside of one sheet surface to the outside of the other sheet surface. Becomes more complicated.

Furthermore, if the piston is formed of a single member as in the prior art, it is necessary to manufacture various types of pistons having different piston lengths according to various requirements such as necessary pressure resistance. However, there is a problem that the manufacturing cost is high.

In addition, when the piston ring is mounted on the outer periphery of the piston, a groove needs to be formed on the outer periphery of the piston, which causes a problem that the processing is complicated.

The present invention has been made by focusing on the conventional problems as described above, and it is possible to simplify the drilling process and other processes for forming the flow path, and to reduce the manufacturing cost by sharing the constituent members. It is an object of the present invention to provide a piston valve structure in a hydraulic buffer that can be modified.

(Means for Solving the Problems) The piston valve structure in the hydraulic shock absorber according to the present invention comprises a piston defining two chambers inside a cylinder filled with fluid, and a plurality of pistons having flow passage holes formed therein. And a communication hole communicating with the flow path inside the sheet surface on one or both sides of the laminated body in which the flow path forming plate material is laminated. A piston valve structure of a hydraulic shock absorber formed by superposing sheet forming members provided with a plurality of sheet forming members. A part is formed, and a piston ring is fitted to the uneven part formed on the outer periphery.

(Operation) In the piston valve structure of the hydraulic shock absorber according to the present invention, when manufacturing a piston, a plurality of flow path forming plate members are overlapped to form a laminate of flow path forming plate members. An uneven portion is formed on the outer periphery of the laminate by stacking different flow path forming plate materials. Then, the piston ring is fitted to the concave and convex portions, and the sheet forming member is further laminated on at least one surface of the laminate, thereby completing the production.

In this case, the communication path that communicates the through hole of the sheet member opened and closed with respect to the chamber defined by the piston and the other chamber is overlapped with the flow path forming hole of the flow path forming plate member and located at the position of the communication hole. It is formed by matching.

The thickness of the piston can be arbitrarily changed by changing the number or thickness of the flow path forming plate members.

When the flow path forming plate is plate-shaped, it can be formed by press molding when processing the flow path forming plate including the flow path forming holes. Furthermore, when the sheet forming member has a small thickness, it is possible to press-mold the sheet forming member including the sheet surface and the communication hole.

Further, by merely overlapping the flow path forming plate members having different outer diameters, the unevenness for preventing the piston ring from coming off is formed without performing complicated groove processing.

(Example) Hereinafter, an example of the present invention will be described in detail with reference to the drawings.

 First, the configuration of the embodiment will be described.

FIG. 1 is a cross-sectional view showing a main part of a piston valve structure in a hydraulic shock absorber according to a first embodiment of the present invention, wherein 1 indicates a cylindrical cylinder. This cylinder 1
Is defined by the slidably mounted piston 2 into two chambers, an upper chamber A and a lower chamber B, and both chambers A and B are filled with a fluid such as oil.

The piston 2 is attached to a tip of a piston rod 3. That is, with respect to the piston rod 3, the rebound stopper 5, the washer 6, the pressure-side damping valve 7, the piston
2, the extension side damping valve 9, the washer 11, the collar 12, the spring seat 13, and the spring 14 are sequentially mounted, and finally the nut 15 is fastened and mounted.

More specifically, the piston 2 includes a sheet forming member 20, a first channel forming plate 21, a second channel forming plate 22, a third channel forming plate 23, a second channel forming plate 22, Road forming plate 2
3, formed by sequentially superimposing the second flow path forming plate 22, the first flow path forming plate 21, and the sheet forming member 20.

The piston rod 3 is located at the center of each member.
A piston projection 2g is formed on the inner peripheral surface of the piston through hole 2a. The positioning projection 2g engages with a vertical groove 3a formed on both sides of the piston rod 3. (See FIGS. 2-5).

On one end surface of the sheet forming member 20, an inner groove 20b and an outer groove 20c are formed inside and outside doubly, and both grooves 20b, 20c are
As shown in FIG. 2, which is a plan view of the sheet forming member 20,
It is formed in an annular shape, and its outer periphery has an inner sheet surface
20d and an outer seat surface 20e are formed.

In the inner groove 20b, two communication holes (communication holes) 20f are provided at three locations at equal intervals in the circumferential direction, respectively.
It is drilled vertically with a phase shift of 20 °.

Further, an annular groove 20h is formed in a chamfered shape at a peripheral portion of the other end surface of the sheet forming member 20.

The sheet forming member 20 is provided at the upper and lower ends of the piston 2 as described above.
It is assembled with the upper end member 20 turned upside down.
Therefore, the position of the communication hole 20f of the upper member 20 and the position of the lower member communication hole 20f are shifted from each other by 60 °.

The pressure-side damping valve 7 is in contact with both seat surfaces 20d and 20e of the sheet forming member 20 provided at the upper end of the piston 2, while the seat surface 20 of the sheet forming member 20 provided at the lower end is provided.
The extension-side damping valve 9 is in contact with d and 20e.
The extension side damping valve 9 is provided with a spring force of a spring 14 via a spring seat 13.

The first flow path forming plate 21 is formed of a slightly thicker plate, and has a circumferential phase of 60 ° as shown in the plan view of FIG.
The small diameter flow path configuration hole 21a and the large diameter flow path configuration hole 2
1b are alternately drilled in total of three. The large-diameter flow path forming hole 21b is formed wide in the outer peripheral direction so as to slightly protrude outward from the inner peripheral edge of the annular groove 20h shown by the chain line in FIG.

As shown in FIG. 1, the first channel forming plate 21 is provided above and below the piston 2 adjacent to the sheet forming member 20, and FIG. 3 shows a plan view of the forming plate member 21. On the other hand, the lower first flow path forming plate member 21 is attached in a state where the position of the projection 2g is inverted to the right from the state of FIG. .

The second flow path forming plate 22 is formed of a thin plate,
As shown in the plan view of FIG. 4, the phase is 60 ° in the circumferential direction.
A total of six small-diameter flow passage forming holes 22a are drilled.

The third flow path forming plate member 23 is formed of a thin plate material and, as shown in the plan view of FIG. 5, is shifted in phase by 60 ° in the circumferential direction and overlaps with the flow path forming hole 22a. A total of six small-diameter passage forming holes 23a are drilled at positions.

The outer diameter of the second flow path forming plate 22 is slightly larger than the first and third flow path forming plates 21 and 23,
Sheet material 21 for the first flow path and two plate materials 23 for the third flow path
By arranging the three second flow path forming plate members 22 therebetween, the piston ring 25 is fitted on the outer peripheral surface of the piston 2 (the outer peripheral surface of the laminated body formed by the plate members 21, 22, and 23). Three annular projections and annular grooves for attachment are alternately formed.

As shown in FIG. 1, the large-diameter flow passage forming holes 21a and 3a continuously arranged in the lower annular groove 20h of the piston 2 are formed.
The pressure side flow path C that connects the inner groove 20b and the lower chamber B is formed by the two flow path configuration holes 22a, the two flow path configuration holes 23a, the small diameter flow path configuration holes 21b, and the communication holes 20f.

On the other hand, a large-diameter flow path forming hole 21a and three flow path forming holes 22a and 2
Two flow path configuration holes 23a, a small diameter flow path configuration hole 21b, and a communication hole 2f.
As a result, the extension side flow path D that connects the inner groove 20b and the upper chamber A is formed.
Is composed.

 Next, the operation of the embodiment will be described.

When manufacturing the piston 2 of this embodiment, the piston 3
On the other hand, the members of each of the members 20 to 23 are simply referred to as the sheet forming member 20, the first flow path forming plate 21, the second flow path forming plate 22, the third flow path forming plate 23, and the second flow path forming plate 23. It is formed by simply superposing the plate member 22, the third channel forming plate member 23, the second channel forming plate member 22, the first channel forming plate member 21, and the sheet forming member 20 in this order.

Then, the pressure side flow path C
And the extension side flow path D is formed by the inner and outer grooves 20b, 20c and the respective flow path forming holes 21a, 2a.
1b, 22a, 23a, both grooves 20b, 20c and each hole 21
By arbitrarily combining the positions and sizes of the holes a, 21b, 22a, and 23a, a flow path can be formed in an arbitrary direction with an arbitrary cross-sectional area.

In addition, since each of the flow path constituent members 21 to 23 has a small thickness, each of the flow path constituent holes 21a, 21b, 22 formed therein is formed.
When forming each of the members 21 to 23 including the members a and 23a, they are formed by press forming which is easy to process.

Therefore, the structure of the present embodiment has a feature that, when manufacturing the piston 2, complicated boring processing is not required and the processing is very easy.

Further, in this production, the piston ring 25 is mounted on the outer periphery of the piston 2. The annular unevenness for mounting the piston ring 25 is also different from the flow path forming members 21, 22, 23, which merely have different outer diameters. Are formed only by alternately stacking, so that groove processing is unnecessary.

Therefore, also in this point, the present embodiment has a feature that processing is very easy.

Further, the piston length can be set arbitrarily only by changing the number of the assembled flow path forming plate members 21, 22, and 23, and the characteristic that the manufacturing cost can be reduced by sharing the constituent members. doing.

Next, the operation of the piston 2 thus manufactured will be described.

(A) At the time of the extension side stroke At the time of the extension side stroke of the piston 2, the fluid in the upper chamber A flows through the extension side flow path D and the inner groove as the hydraulic pressure of the upper chamber A increases.
20b, from which the expansion damping valve 9 is opened to flow into the lower chamber B.

Therefore, a damping force having a speed 2/3 power characteristic is generated in series between the inner seat surface 20d and the outer seat surface 20e, and the extension damping valve 9.

In other words, in the case of this speed 2/3 power characteristic, the rate of change decreases with an increase in piston speed. By obtaining this characteristic in series, the decrease in the rate of change of the damping force is suppressed, and linear damping is achieved. Power is gained.

(B) During the compression-side stroke During the compression-side stroke of the piston 2, the operation is substantially symmetrical to that of the above-described extension-side stroke. That is, when the pressure side stroke is completed and the hydraulic pressure in the lower chamber B rises, the working fluid in the lower chamber B flows into the inner groove 20b via the pressure side flow path C, and from there,
The compression side damping valve 7 is opened and flows into the upper chamber A.

Accordingly, a damping force having a speed 2/3 power characteristic is generated in series between the inner seat surface 20d and the outer seat surface 20e and the compression side damping valve 7, and a linear damping force characteristic linearly proportional to the piston speed is obtained. Can be

As described above, the piston valve structure of the hydraulic shock absorber according to the first embodiment has a feature that a first-order linear damping force characteristic can be obtained in the both-stretching stroke. Thus, since the linear characteristics are obtained, the characteristics do not suddenly change depending on the piston speed, and when applied to a vehicle suspension, it is possible to achieve both riding comfort and steering stability. Characteristic is obtained.

Next, a second embodiment shown in FIGS. 6 to 9 will be described. In the description of the second embodiment, the same components as those in the first embodiment are denoted by the same reference numerals as those in the first embodiment, and description thereof will be omitted. Only different points will be described.

The second embodiment is an example in which not only the channel forming plate but also the sheet forming member is formed of a plate.

That is, as shown in FIG. 6, the piston 2 includes a sheet forming member 40, a first flow path forming plate 41, a second flow path forming plate 42, a first flow path forming plate 41, and a second flow path forming plate 42. The first flow path forming plate member 41 and the sheet forming member 40 are sequentially laminated.

The sheet forming member 40 is formed of a plate material. As shown in the plan view of FIG. 7, a total of four opening windows (communication holes) 40a are formed by shifting the phase by 90 ° in the circumferential direction. ,
A sheet surface 40b is formed therearound, and each opening window 4
Notches 40c for forming a flow path are formed between the respective 0a.

Note that the sheet forming member 40 at the upper end of the piston 2 and the sheet forming member 40 at the lower end of the piston are provided with a phase shifted by 45 °, so that both sheet forming members 40, 40 are connected to one opening window 40a. And the other cutout portion 40c are attached so that they coincide with each other in the vertical direction.

The first flow path forming plate 41 and the second flow path forming plate 42 have eight flow path forming holes 41a at equal intervals in the circumferential direction.
42a are each drilled.

That is, in the second embodiment, the lower sheet forming member 40
The notch 40c, the three flow path forming holes 41a, and the two flow path forming holes 42a form a pressure side flow path C that communicates the opening window 40a of the upper sheet forming member 40 with the lower chamber B. The notch 40c of the upper sheet forming member 40 and the three flow path forming holes 4
1a and the two flow path forming holes 42a, the extension side flow path D connecting the opening window 40a of the lower sheet forming member 40 and the upper chamber A.
Is composed.

Therefore, in the piston valve structure of the hydraulic shock absorber according to the second embodiment, since the sheet forming member 40 is also formed of a plate material, this can also be manufactured by pressing.
Manufacturing costs can be reduced.

Although the embodiment of the present invention has been described in detail with reference to the drawings, the specific configuration is not limited to this embodiment, and even if there is a design change without departing from the gist of the present invention, the present invention is not limited to this embodiment. included.

For example, in the embodiment, an example is shown in which both the expansion side and the compression side damping valves are provided in the piston, but the invention may be applied to only one of them.

(Effects of the Invention) As described above, in the piston valve structure of the hydraulic shock absorber of the present invention, the piston is formed by overlapping the flow path forming plate and the sheet forming member, and is formed in the communication hole of the sheet forming member. Since the flow paths to be communicated with each other are formed by flow path forming holes formed in the flow path forming plate material, the flow path forming plate material is simply formed without forming a hole in forming the flow path. Processing can be performed simply by overlapping, and the effect that processing can be simplified is obtained. In addition, since the formation of each flow path forming hole can be easily performed by pressing, the processing can be further simplified. can get.

Further, in forming the flow path in this manner, the flow path can be formed in an arbitrary direction by arbitrarily combining the drilling positions and sizes of the respective flow path forming holes, thereby also simplifying the processing. The effect is obtained.

Furthermore, the piston length can be arbitrarily set according to the required pressure resistance or the like by changing the number of sheets or the thickness of the flow path forming plate material, so that the constituent members can be shared and the manufacturing cost can be reduced. The effect is obtained.

In addition, since there is no need to form a groove for mounting the piston ring, an effect is obtained that processing can be further simplified.

[Brief description of the drawings]

FIG. 1 is a sectional view showing a main part of a piston valve structure in a hydraulic shock absorber according to a first embodiment of the present invention, FIG. 2 is a plan view showing a seat forming member of the first embodiment structure, and FIG. FIG. 4 is a plan view showing a first flow path forming plate of the first embodiment, FIG. 4 is a plan view showing a second flow path forming plate of the first embodiment, and FIG. 5 is a third flow forming plate of the first embodiment. FIG. 6 is a sectional view showing a main part of a piston valve structure in the hydraulic shock absorber of the second embodiment, FIG. 7 is a plan view showing a seat forming member of the embodiment, FIG. FIG. 9 is a plan view showing a first flow path forming plate of the embodiment, and FIG. 9 is a plan view showing a second flow path forming plate of the embodiment. A: Upper chamber B: Lower chamber C: Compression side channel D: Extension side channel 1 ... Cylinder 2 ... Piston 7: Compression side damping valve 9 ... Extension side damping valve 20 ... Compression side sheet forming member 20d ... Inner seat surface 20e ... Outside Sheet surface 20f: communication hole (communication hole) 21: first flow path forming plate 21a: small diameter flow path forming hole 21b: large diameter flow path forming hole 22: second flow path forming plate 22a: flow path forming hole 23 ... second flow path forming plate material 23a ... flow path forming hole 40 ... sheet forming member 40a ... opening window (communication hole) 41 ... first flow path forming plate material 41a ... flow path forming hole 42 ... second flow path forming plate material 42a ... Channel configuration hole

Claims (1)

(57) [Scope of request for utility model registration] A piston for defining a fluid-filled cylinder in two chambers is formed by laminating a plurality of flow path forming plates provided with flow path forming holes, and laminating the flow path forming plates. A hydraulic shock absorber formed by superimposing a sheet forming member having a sheet surface with which a damping valve abuts and a communication hole communicating with the flow path inside the sheet surface on one or both surfaces of the laminated body. The laminated body of the flow path forming plate material, the flow path forming plate material having a different outer diameter is overlapped to form an uneven portion on the outer periphery thereof, and a piston ring is formed on the uneven portion formed on the outer circumference. A piston valve structure in the hydraulic shock absorber, which is fitted.