JPH0332834Y2 - - Google Patents

Description

[Detailed description of the invention] [Field of industrial application] The present invention relates to a piston in a hydraulic shock absorber.
In particular, a dual-effect type in which a pair of bodies with inlet ports and outlet ports arranged in parallel are overlapped, the inlet port of one body is communicated with the outlet port of the other body, and a leaf valve is provided at the mouth end of each outlet port. Regarding the piston.

[Conventional technology]

A piston having a structure shown in FIGS. 3 and 4 is known as a conventional expansion/compression type piston of this type.

The piston in Fig. 3 has two ports 2 and 3 formed diagonally on the piston body 1, and port 2.
Leaf valves 4 and 5 are provided at the lower mouth end of the port 3 and the upper mouth end of the port 3, respectively, so as to be openable and closable.

The piston shown in FIG. 4 has straight ports 6, 7 parallel to the piston body 1, and has stepped seat parts 10, 10 protruding from both ends of the piston body 1. , 7 are provided with a leaf valve facing them.

However, in the former case, drilling is required to form the ports 2 and 3 in the diagonal direction, which makes processing difficult and expensive.

In the latter case, since the sheet surface is not a uniform circumferential surface, it is necessary to control the flatness of the sheet surface particularly strictly.

Therefore, in order to solve these drawbacks, a piston as disclosed in Japanese Patent Publication No. 48-21378, for example, has been developed.

This piston consists of two disks stacked face-to-face, each disk having an inlet hole and an outlet hole, and each outlet hole provided with a valve plate that can be opened and closed.

[Problem that the invention attempts to solve]

The piston disclosed in the above publication is easy to hole and the seat surface of the valve plate is a uniform ring, so there is no need to strictly control the flatness.
Since the length and size of the outlet hole and the inlet hole are constant, port characteristics cannot be set arbitrarily.

If the sizes of the outlet and inlet holes are changed in order to change the port characteristics, there is also the problem that the temperature characteristics deteriorate depending on the length of the holes.

Therefore, the purpose of the present invention is to facilitate hole machining,
To provide a piston in a hydraulic shock absorber which does not require strict management of the flatness of a seat surface, allows port characteristics to be set arbitrarily, and has a damping function in both expansion and compression directions without degrading temperature characteristics.

[Means for solving problems]

In order to achieve the above purpose, the configuration of the present invention is as follows:
A pair of bodies provided with an inlet port and an outlet port in parallel are stacked on top of each other with a valve plate interposed between the two bodies, and the inlet port of one body is opposed to the outlet port of the other body to form a passage. Further, a leaf valve is disposed at the mouth end of the outlet port of each body so as to be freely openable and closable, and the valve plate has a passage for communicating the inlet port of one body with the outlet port of the other body and setting the port characteristics. It is characterized by the formation of oil holes.

[Effect]

When oil flows through a passage consisting of an inlet port and an outlet port, the port characteristics are obtained by the oil passage holes.

〔Example〕

An example of implementing the present invention will be described below with reference to FIG.

A piston 11 according to the present invention is slidably inserted into a cylinder 12 to partition the cylinder 12 into two upper and lower oil chambers 13 and 14.

The piston 11 has a pair of bodies 15 of the same structure,
16 and a valve plate 27, each body 15, 16
are stacked on top of each other with a valve plate 27 interposed between them.

Each body 15, 16 has an inlet port 17, 17.
and outlet ports 18, 18 are respectively bored parallel to, for example parallel to, the axis.

The inner end opening of the inlet port 17 provided in one body 15 is opposed to the opening of the outlet port 18 provided in the other body 16, and
The outlet port 18 of the body 16 is opposed to the mouth end of the inlet port 17 of the other body 16.

An oil passage hole 25 consisting of a hole or notch for setting port characteristics is bored in the valve plate, and this hole is connected to the inlet port 17.
and an outlet port 18 .

Inlet port 17 provided in each body 15, 16,
The inlet side mouth end of 17 opens at a position away from the center of the bodies 15, 16, and the inlet ports 17, 1
The outlet end of body 1 and the outlet ports 18 and 18 of each body 15 and 16 coincide with each other.
It is bored near the center of 5.16.

The two bodies 15 and 16 have the same shape and structure, and are superimposed with one body 15 displaced, for example, by 180 degrees, and at this time, one inlet port 17 is connected to the other body 16. It is opposite to the outlet port 18.

The inlet port 17 has an axial port portion 17a and a radial port portion 17b, and the radial port portion 17b is formed on the inner end surface side of the bodies 15 and 16.

Since the port characteristics are determined by the size of the oil passage hole 25, the size may be arbitrarily set in accordance with the desired port characteristics.

The piston 11 is held by a piston rod 19, and its installation involves sequentially attaching a valve holder 22, a leaf valve 20, a body 15, a valve plate 27, a body 16, a leaf valve 21, and a valve holder 22 to the stepped portion of the piston rod 19. It is inserted and then tightened with a piston nut 24.

The leaf valve 20 is a valve for generating a damping force on the compression side, and is in contact with the seat surface of the mouth end of the upper outlet port 18 so as to be openable and closable, and the leaf valve 21, also on the lower side, is a valve for generating a damping force on the rebound side. can be,
This abuts the mouth end seat surface of the lower outlet port 18 so as to be openable and closable. The seat surface is composed of ring-shaped protrusions.

According to the hydraulic shock absorber incorporating the piston 11 described above, the piston 11 moves to the left in the figure when it is extended, and at this time the oil in the upper oil chamber 13 flows from the inlet port 17 to
Lower oil chamber 1 via oil passage hole 25-outlet port 18
At this time, the leaf valve 21 is bent downward, and the leaf valve 21 generates a damping force on the expansion side, and the oil passage hole 25 provides port characteristics.

Conversely, during compression operation, the piston 11 moves to the right, and the oil in the lower oil chamber 14 flows from the lower inlet port 17 to the oil passage hole 2.
5 - The oil flows from the upper outlet port 18 to the upper oil chamber 13, and at this time, a compression side damping force is generated by the bending of the upper leaf valve 20, and the port characteristics due to the oil passage hole 25 are obtained. By arbitrarily adjusting the size of the oil passage hole 25, port characteristics corresponding to the size can be obtained. However, it is possible to make a plurality of valve plates with different sizes of the oil passage hole 25 in advance and adjust them each time. You may select and combine them.

FIG. 2 shows another embodiment of the invention, in which the piston 11 is mounted on a hollow piston rod 19a.

A passage 30 is provided in the center of the piston rod 19a, and this passage 30 communicates with the through holes 29 and 31.
The upper through hole 31 opens into the upper oil chamber 13 .

Furthermore, one body 16 constituting the piston 11
a passageway 28 opening into the outlet port 18 is drilled;
This passage 28 is a through hole 29 of the piston rod 19a.
It communicates with the passageway 30 via. Therefore, during the extension operation, there are two oil passages, one flowing from the upper inlet port 17 and the other oil passage flowing from the passage 31 - passage 30 - passage 29 - passage 28.

Therefore, in this case, a sufficient flow rate is ensured.
If a damping force adjustment valve is incorporated in the passage 30, it can also be used as a piston of a damping force adjustable hydraulic shock absorber, and can also be used as a piston of an oil lock type hydraulic shock absorber.

[Effect of idea]

According to the present invention, the following effects are achieved.

Since an oil passage hole is formed for communicating port characteristics between the inlet port and the outlet port, port characteristics corresponding to the oil passage hole can be obtained.

Port characteristics can be changed arbitrarily by selecting the size of the oil passage hole.

Since the oil passage hole is formed in the valve hole, its length is short, so the temperature characteristics do not deteriorate.

The piston is made by stacking two bodies of the same structure, and the body and port can be molded.
Easy to drill holes.

Since the seat surface against which the leaf valve comes into contact may be ring-shaped, strict control of the flatness of the seat surface is not required.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of a piston according to one embodiment of the present invention, FIG. 2 is a sectional view of a piston according to another embodiment, and FIGS. 3 and 4 are sectional views of a conventional piston. 11... Piston, 15, 16... Body, 1
7...Inlet port, 18...Outlet port, 25...
...Oil hole.

Claims (1)

[Scope of utility model registration request] A pair of bodies each having an inlet port and an outlet port provided in parallel are stacked on top of each other with a valve plate interposed between the two bodies, and the inlet port of one body is opposed to the outlet port of the other body to form a passage. Further, a leaf valve is disposed at the mouth end of the outlet port of each body so as to be openable and closable, and the valve plate is provided with a passage for communicating the inlet port of one body with the outlet port of the other body and for setting the port characteristics. A piston structure in a hydraulic shock absorber characterized by forming an oil hole.