JPH0329625Y2 - - 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 pair of bodies with inlet ports and outlet ports arranged in parallel are stacked face-to-face, the inlet port of one body communicates with the outlet port of the other body, and a leaf valve is provided at the mouth end of each outlet port. Regarding double-acting type pistons.

[Conventional technology]

A piston having a structure shown in FIGS. 4 and 5 is known as a conventional expansion/compression type piston of this kind.

The piston shown in Fig. 4 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. 5 has straight ports 6 and 7 parallel to the piston body 1, and seat portions 10 and 10 with steps at both ends of the piston body 1. , 7 are provided with upper and lower leaf valves, respectively.

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 particularly strictly control the flatness of the sheet surface.

Therefore, in order to eliminate 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 drill holes in, and the seat surface of the valve plate is a uniform ring, so there is no need to strictly control the degree of 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 having inlet ports and outlet ports arranged in parallel are stacked face-to-face, and the inlet port of one body communicates with the outlet port of the other body to form a passage, and the outlet port of each body communicates with the outlet port of the other body. In a piston in which a leaf valve is disposed at the end so as to be freely openable and closable, the inlet port consists of an axial port section passing through the body and a radial port section formed on the end surface of the body. The present invention is characterized in that a partition wall is provided in the middle of the port portion, and an oil passage hole for setting the port characteristics is formed in the partition wall.

[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 hole.

〔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 each body 15, 16 is stacked face-to-face with horizontal inner end surfaces interposed therebetween.

Each body 15, 16 has an inlet port 17, 17 and an outlet port 18, 18 in parallel with the axis,
For example, they are perforated in parallel.

The inner end side opening of the inlet port 17 provided in one body 15 is joined to the opening of the outlet port 18 provided in the other body 16, and
The outlet port 18 of the body 16 is connected to the mouth end of the inlet port 17 of the other body 16 to form a passage.

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 joined face-to-face by displacing the other body 16 by, for example, 180 degrees with respect to the one body 15, and at this time, one of the inlet ports 17 is opposite the other 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.

A partition wall 27 is provided in the middle of the port portion 17b in the radial direction.
An etched groove 25 is formed in this partition wall 27 downward from the upper end, and this etched groove 25 allows ports on both sides of the partition wall 27 to communicate.

(Fig. 3) Since the engraved groove 25 is used as a communication hole for setting port characteristics, it is located in the center of the partition wall,
Alternatively, the hole may be bored at any other arbitrary position.

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

The piston 11 is held by the piston rod 19, and its installation involves inserting the valve holder 22, leaf valve 20, piston 11, leaf valve 21, and valve holder 22 into the stepped portion of the piston rod 19 in order, and then tightening the piston nut 24. It is tightened with.

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 extended,
At this time, the oil in the upper oil chamber 13 flows into the lower oil chamber 14 via the inlet port 17, the groove 25, and the outlet port 18, and at this time, the leaf valve 21 is bent downward, and the leaf valve 21 causes expansion side damping. A force is generated, and port characteristics due to the engraved grooves 25 are obtained.

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 stamped groove 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 engraved grooves 25 are obtained.

By arbitrarily adjusting the size of the engraved groove 25, port characteristics corresponding to the size can be obtained. However, by making a plurality of bodies with different sized engraved grooves 25 in advance, the desired body can be selected each time. may be combined.

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

A passage 20 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.

A partition wall is provided in the middle of the inlet port, and an oil passage hole for setting port characteristics, which is an engraved groove or a hole, is formed in this partition wall, so that 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.

The length of the oil passage hole is short because it is only provided in the partition wall, so the temperature characteristics will not deteriorate.

The radial port portion is formed on the end face of the body, and the port portion, partition wall, and communication hole can be integrally molded with the body, improving workability, reducing the number of parts, making it compact, and making assembly easier. Excellent flexibility and economy.

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 necessary.

[Brief explanation of drawings]

1 is a cross-sectional view of a piston according to one embodiment of the present invention, FIG. 2 is a cross-sectional view of a piston according to another embodiment, FIG. 3 is an enlarged perspective view of the embossing groove portion of FIG. FIG. 5 is a sectional view of a conventional piston. 11... Piston, 15, 16... Body, 1
7...Inlet port, 18...Outlet port, 25...
...Essential groove.

Claims (1)

[Claims for Utility Model Registration] (1) A pair of bodies in which an inlet port and an outlet port are provided in parallel are stacked face-to-face, and the inlet port of one body is communicated with the outlet port of the other body to form a passage. In the piston, a leaf valve is arranged at the mouth end of the outlet port of each body so as to be openable and closable, and the inlet port has an axial port portion passing through the body and a radius formed on the end surface of the body. A piston structure for a hydraulic shock absorber, characterized in that the piston structure comprises a radial port part, a partition wall is provided in the middle of the radial port part, and an oil passage hole for setting port characteristics is formed in the partition wall. (2) The piston structure in the hydraulic shock absorber according to claim 1, wherein the oil passage hole is a stamped groove cut downward from the upper end of the partition wall. (3) The piston structure in the hydraulic shock absorber according to claim 1, wherein the oil passage hole is a hole formed in the center of the partition wall.