JPS5817140Y2 - hydraulic shock absorber - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a hydraulic shock absorber in which orifice characteristics and valve characteristics can be switched in multiple stages using one pressure regulating section.

The structure of a conventional hydraulic shock absorber equipped with a pressure regulating valve as a pressure regulating section is shown in FIG. 1, and the prior art will be explained with reference to FIGS. 1, 2, and 6.

A conventional pressure regulating valve 1 includes a valve body 3 that abuts a valve seat portion 2a that is integrally formed inside a cylindrical valve body 2, and a compression coil spring 4 that biases the valve body 3 toward the valve seat. , the main component is an adjustment screw 5 that holds the upper end of the valve body 3 so as to be slidable in the vertical direction and is in contact with one end of a compression coil spring 4 to adjust the initial pressure of the compression coil spring 4. The internal space of the valve body 2 is divided into an upper chamber 2b and a lower chamber 2C by the valve seat portion 2a and the valve body 3 pressed against the valve seat portion 2a.

An orifice 3a is formed inside the valve body 3 to communicate the upper chamber 2b and the lower chamber 2C with each other, and communication holes 2d and 2e are formed in the side wall of the upper chamber 2b and the side wall of the lower chamber 2C, respectively. .

5a is a threaded portion, and 5b is a seal ring.

5C is a hole formed in the adjustment screw 5 for slidably supporting the upper end of the valve body 3.

A partition wall 7 is formed inside the cylinder portion 6a of the shock absorber 6, and a piston 10 is housed in an oil chamber 9 in a portion narrowed between the partition wall 7 and the lid body 8 inside the cylinder portion a. .

The piston 10 is provided with relief valves 10 a in opposite directions.
, 10b are installed, and the piston rod 11 is also installed.

The piston rod 11 is supported by the partition wall 7 and the lid 8, and is slidable in the left and right directions in the figure.

The oil chamber 9 is divided into an A chamber and a B chamber by a piston 10, and the A chamber and the B chamber are filled with oil.

A pressure regulating valve 1.1 is attached to the upper part of the A chamber and the B chamber, respectively, and the lower chambers 2C, 2C of the pressure regulating valves 1, 1 are connected to the A chamber, the lower chambers 2C, 2C through communication holes 6b, 6b formed in the cylinder portion 6a, respectively. It is connected to room B.

An oil passage pipe 12.13 is interposed between these pressure regulating valves 1, 1, and the oil passage pipe 12.13 independently connects the upper chamber of one pressure regulating valve and the lower chamber of the other pressure regulating valve. It goes through.

It goes without saying that the insides of the pressure regulating valves 1 and 1 and the insides of the oil passage pipes 12 and 13 are filled with oil fluid.

Piston rod 11 slides to the right, and at the same time piston 1
0 also moves to the right, when the piston speed is slow, the oil in the B chamber flows from the lower chamber 2C to the upper chamber 2b through the orifice 3a formed in the valve body 3 of the pressure regulating valve 1, and from the upper chamber 2b. The lower chamber 2 of the other pressure regulating valve 1 via the oil passage pipe 13
It flows into room C and from there into room A.

The damping force at this time is generated by the orifice 3a, and the damping force characteristics at this time are shown by the characteristics shown in FIG.

When the piston speed further increases, the oil pressure in chamber B increases, the valve body 3 opens against the elastic force of the compression coil spring 4, and the oil flows into chamber A through the same path as described above. .

At this time, the hydraulic damping force is mainly caused by the valve seat 2a and the orifice 3.
The damping force characteristic of the hydraulic damper is shown by characteristic II in FIG. 6.

It is clear that the characteristic II is a combination of the characteristic (2) due to the orifice and the characteristic at the valve seat portion 2a of the pressure regulating valve 1.

When the piston speed further increases and the pressure in chamber B increases, the relief valve 10a opens, and the damping force characteristic of the hydraulic shock absorber becomes as shown by characteristic III in FIG.

Characteristic III is characteristic ■, characteristic II and IJ leaf valve 1
This is a combination of the damping force characteristics at 0 a.

In FIG. 6, point C indicates the opening point of the pressure regulating valve 1, and point D indicates the opening point of the relief valve 10a.

Generally, the damping force characteristics of a hydraulic shock absorber are determined according to the piston speed, but in large hydraulic shock absorbers such as earthquake-proof hydraulic shock absorbers for spherical tanks, when the damping force becomes large, it is necessary to install it. The mounting part and foundation have to be large in terms of strength.

Further, when the piston speed exceeds a predetermined value, the high damping force causes an adverse effect such as destruction on the shock absorber itself or the structure to which it is attached, and to prevent this, the above-mentioned relief valve is provided.

However, as mentioned above, the relief valve is provided independently in a part different from the characteristic valve part of the hydraulic shock absorber, so the presence of two valve parts that require machining precision makes manufacturing difficult. The disadvantage is that it requires space to store.

Furthermore, since the relief valve is provided separately from the characteristic valve, maintenance is difficult and assembly is not easy.

The purpose of the present invention is to provide a hydraulic shock absorber that can eliminate the drawbacks of the prior art described above.The feature is that a piston equipped with a piston rod is housed in a cylinder filled with oil. In a hydraulic shock absorber, the inside of the cylinder is divided into two chambers by a piston, and the pressure regulating section is interposed between the two chambers and allows the oil to flow in mutually opposite directions,
The pressure regulating section has a first valve body and a second valve body which are slidably arranged independently from each other and on the same axis, and the first valve body has one of the two chambers and the pressure regulating part. one end facing a pressure regulation inlet that communicates with the inside of the pressure section and the other end opening into the pressure regulation section leading to the other of the two chambers, and a direction in which the pressure regulation inlet closes the first valve body; the second valve body is formed with an orifice whose one end faces the opening of the first valve body and the other end opens into the pressure regulating section, and the second valve body is biased toward the first valve body. is biased in a direction in which the opening of the opening is closed, and in a first pressure state in which the pressure regulating section receives pressure, the first valve body serves as a valve seat for the second valve body, and only the second valve body opens; In a second pressure state relatively greater than the first pressure state, the first valve body and the second valve body open simultaneously.

An embodiment of the present invention will be described below with reference to FIGS. 3 to 6.

In the figures, members given the same numbers as those in the above-described embodiments indicate members with the same names.

A relief valve body 14 is in contact with the valve seat portion 2a, and the relief valve body 14 has an opening 14a formed in its center.

A compression coil spring 15 is interposed between the relief valve body 14 and the adjustment screw 5, and the relief valve 14 is pressed against the valve seat portion 2a by the elastic force of the compression coil spring 15.

A pressure regulating valve body 16 is located in the upper part of the relief valve body 14 with its lower end inserted into the opening 14a, and the upper end of the pressure regulating valve body 16 is supported by a hole formed in the adjustment screw 5.
6 is slidable in the vertical direction in the figure.

A compression coil spring 17 is interposed between the valve body 16 and the adjustment screw 5, and presses the valve body 16 against the relief valve body 14.

16a indicates an orifice formed inside the valve body 16.

In addition, in order to adjust the initial pressures of the pressure regulating valve body 16 and the IJ 17 first valve body 14 separately, as shown in the opening of FIG.
The adjustment screw 5 is connected to an external adjustment screw 5d' for the compression coil spring 15 to come into contact with, and a compression coil spring 17.
It can be configured by an internal adjustment screw 5e for abutment.

That is, the screw 5d and the screw 5e are relatively movable.

The action will be explained below.

As mentioned in the explanation of the prior art, when the piston speed of the hydraulic shock absorber is slow, the oil flows only through the orifice 16a (characteristic ■ shown in FIG. First, the pressure regulating valve body 16 overcomes the elastic force of the compression coil spring 17 and rises, and the oil flow path is expanded as shown in FIG. 4 (Characteristic II).

When the piston speed further increases, the relief valve body 14 also rises, and as shown in FIG. 5, the oil flow path is further expanded.

(Characteristic III). Note that depending on the size of the cylinder 2, the relief valve may be provided in two or three stages.

As explained above, according to the hydraulic shock absorber of the present invention, since the pressure regulating valve part and the IJ valve part are located in the same part,
This has the effect of reducing the number of valve parts that require machining precision and making manufacturing easier.

In addition, the space for housing the relief valve is reduced, and the assembly of the valve is advantageous in terms of strength and design.

Furthermore, there is also the effect that adjustment and maintenance of valve characteristics including the relief valve is easy.

Further, since a plurality of valve bodies can be combined depending on the size of the valve portion, the hydraulic resistance force applied to each member can be kept low even when the piston speed increases.

[Brief explanation of the drawing]

Fig. 1 is a sectional view of a conventional hydraulic shock absorber, Fig. 2 is a sectional view of a conventional pressure regulating valve, and Fig. 3 A is a sectional view of a pressure regulating valve of the present invention.
The opening is a sectional view of the main part of another embodiment of the pressure regulating valve of the present invention, No. 4.
The figure is an explanation of the operation of the present invention, and Figure 5 is an illustration of the operation of the present invention.
FIG. 6 is a characteristic diagram of the hydraulic shock absorber. 2... Valve body, 2a... Valve seat part, 2b
... Upper chamber, 2C... Lower chamber, 2d,
2e...Communication hole, 5...Adjustment screw, 6
a...Cylinder part, 14...Relief valve body, 14a...Open hole, 15.17...
・Compression coil spring, 16...pressure regulating valve body.

Claims (1)

[Scope of utility model registration request] (1) A piston equipped with a piston rod is housed in a cylinder filled with oil, and the inside of the cylinder is divided into two chambers by the piston, and the two chambers are interposed between the two chambers and the piston rod is installed in the cylinder. In a hydraulic shock absorber having a pressure regulating section through which oil flows, the pressure regulating section has a first valve body and a second valve body which are slidably arranged independently of each other and on the same axis, forming an opening in the first valve body, one end facing a pressure regulating inlet that communicates one of the two chambers with the inside of the pressure regulating section, and the other end opening into the pressure regulating section leading to the other of the two chambers; The first valve body is biased in a direction in which the pressure regulating inlet is closed, and the second valve body has an orifice with one end facing the opening of the first valve body and the other end opening into the pressure regulating part. forming the second
The valve body is biased in a direction in which the opening of the first valve body is closed, and in a first pressure state where the pressure regulating section receives pressure, the first valve body serves as a valve seat of the second valve body and the opening of the first valve body is biased. A hydraulic shock absorber characterized in that only two valve bodies open, and in a second pressure state relatively greater than the first pressure state, the first valve body and the second valve body open simultaneously.