JPS631098Y2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a spool valve that controls fluid flow by driving the spool using electromagnetic operating force, mechanical operating force, or fluid pressure operating force.

Conventionally, in this type of spool valve, as illustrated in FIG. c may float up and come off from the circumferential groove b due to fluid flow or the like. There are various possible causes for this, but in particular, when the high-pressure fluid that has flowed in between the O-ring c and the bottom of the circumferential groove b separates the O-ring from the valve seat etc. during spool switching. , one of the main causes is thought to be that the O-ring is pushed up to escape from the circumferential groove b. In order to prevent the O-ring from slipping out in this way, use an O-ring with a large wire diameter and fit it into the circumferential groove b of the spool a with its inner diameter extremely expanded, thereby preventing the O-ring's mechanical The strength is increased, but in this case, the deformation of the strength is prevented by O-ring c.
This may promote compression set and deterioration of physical properties, and furthermore, due to the deformation of the strength, the elastic force will decrease, resulting in increased sliding resistance, decreased sealing performance, and increased wear and tear due to sliding. This leads to a decline in various performances required of spool valves such as spool valves.

Furthermore, as shown in Japanese Patent Publication No. 48-4647, the width of the O-ring in the radial direction of the spool is larger than the thickness in the axial direction of the spool to increase the strength against diameter expansion. However, if a space is formed between the O-ring and the bottom of the circumferential groove where the high-pressure fluid is sealed, the upward force caused by the high-pressure fluid will repeatedly act. Therefore, it cannot be said to be an essential solution to the problem of O-ring escape.

The object of the present invention is to obtain a spool valve in which the upward force of the O-ring due to fluid pressure does not act, thereby effectively suppressing the escape of the O-ring from the outer circumferential groove of the spool. It is something.

In order to achieve the above purpose, in this invention,
The elastic annular body that fits into the outer circumferential groove of the spool valve has a width in the radial direction of the spool larger than a thickness in the axial direction of the spool, and a thickness smaller than the width in the axial direction of the spool of the outer circumferential groove. A gap is formed across the entire depth of the outer groove between the end face of the groove and the side wall of the outer groove. Similar to conventional O-rings, the inner circumference of the elastic ring contacts the inner bottom of the outer circumferential groove of the spool,
It goes without saying that the outer periphery of the valve casing is in contact with the inner wall of the valve casing to form a seal.

In a spool valve having such a configuration, high-pressure fluid freely enters and exits the outer circumferential groove of the spool, and a sealed space in which the high-pressure fluid is confined is not formed within the outer circumferential groove. No push-up force is applied. Moreover, since the width of the elastic ring in the radial direction of the spool is made larger than the thickness in the axial direction of the spool, the resistance against diameter expansion becomes extremely large.

According to the spool valve of the present invention, as described above, the resistance against the diameter expansion of the elastic ring is extremely large, and in combination with the fact that the upward force of the high-pressure fluid does not act on the elastic ring, the elastic ring It is possible to effectively prevent the ring from coming off the outer circumferential groove of the spool.

Furthermore, as shown in, for example, Japanese Utility Model Application Publication No. 157760/1983, the side surface of the elastic ring body is brought into contact with the inner surface of the outer groove without bringing the elastic ring body into contact with the inner bottom of the outer groove of the spool. In the case of products that are brought into contact and sealed, the inner surface of the groove is generally difficult to process.
Moreover, since the fluid pressure seal is performed using a face seal in which relatively wide surfaces contact each other, a sufficient sealing effect cannot be obtained.Furthermore, the sealing force is generated by the fluid pressure, so for example, in the case of a low-pressure fluid, the seal may not be effective. However, the present invention does not have such drawbacks, and it is possible to perform a line seal equivalent to a known O-ring by using the inner bottom surface of the outer circumferential groove, which is easy to finish. The desired effect can be expected while retaining the excellent characteristics of known O-rings, such as being able to apply sealing force through the elasticity of the ring body itself.

Examples of the present invention will be described in detail below.

In the embodiment of the present invention shown in FIG. 2, 1 is a valve housing of a directional valve, 2 is a spool inserted inside the valve housing so as to be slidable in the axial direction, and this spool 2 acts on the end. It is driven by electromagnetic operating force, mechanical operating force, or fluid pressure operating force.

The inner wall of the valve housing 1 has a supply port 3, output ports 4a, 4b, and discharge ports 5a, 5b bored in the valve housing.
Inner circumferential grooves 6, 7a, 7b, 8a, and 8b communicating with the inner circumferential grooves are provided, and a valve seat portion 9 is formed on the inner wall of the valve casing between these inner circumferential grooves.
a, 9b, 10a, 10b, and the spool 2 has an elastic ring 11a that contacts the valve seat 9a or 10a, and an elastic ring 11b that contacts the valve seat 10b or 9b. 12a,
12b, these elastic rings are provided around the circumference. The elastic rings 11a, 11b
, which opens and closes the flow path between the supply port 3, the output ports 4a, 4b, and the discharge ports 5a, 5b, which are opened on the inner wall of the valve casing by contacting the valve seat part of the inner wall of the valve casing, is made of an elastic material. and as shown in FIG.
The maximum width w in the radial direction of the spool in its cross-sectional shape
is formed to be larger than the maximum thickness t in the spool axial direction. Also, the maximum thickness t of the elastic rings 11a and 11b is determined by the outer circumferential grooves 12a and 12b into which they are fitted.
A gap 13 is formed between the end surfaces of the elastic ring bodies 11a, 11b and the side walls of the outer circumferential grooves 12a, 12b over the entire depth of the outer circumferential grooves 12a, 12b. The elastic ring bodies 11a, 11b are fitted into the outer circumferential grooves with their inner circumferences in contact with the inner bottoms of the outer circumferential grooves 12a, 12b of the spool 2, similar to known O-rings, and their outer circumferences are attached to the inner wall of the valve casing. Of course, sealing can be performed by bringing the material into contact with the material.

In the figure, 14a and 14b are seal members provided around the spool 2 at both ends, and have the same structure as the elastic rings 11a and 11b, but these seal members escape from the outer circumferential grooves 12a and 12b. Therefore, conventionally used sealing members and the like can be used.

The four-way switching valve having such a configuration is configured such that when the spool 2 is in the position shown in FIG.
Fluid from the supply port 3 flows to the output port 4a, fluid from the output port 4b flows to the discharge port 5b, and when the spool 2 is switched to the other switching position, fluid from the supply port 3 flows to the output port 4b. With,
Fluid from the output port 4a is discharged through the discharge port 5a. No matter which of these switching positions the spool 2 is in, the elastic rings 11a, 11b have the supply ports 3
Fluid pressure acts from the side, and as a result, the elastic rings 11a, 11b seal off the fluid while being pressed against the low-pressure side walls of the outer circumferential grooves 12a, 12b. However, it does not provide a fluid seal with the side wall.

Since the elastic rings 11a and 11b have a width w in the radial direction of the spool larger than a thickness t in the axial direction of the spool, they have sufficient resistance against expansion of the diameter and have great flexibility in the axial direction of the spool. Therefore, even in the middle of switching as shown in FIG. 3, the elastic rings 11a and 11b do not lift up from the outer circumferential grooves 12a and 12b of the spool, and can move in the axial direction of the spool during switching. The sliding resistance is also reduced.

In addition, when using a conventional O-ring, the first
As shown in the figure, the flow of fluid, especially the high-pressure fluid that has flowed between O-ring c and the bottom of circumferential groove b, pushes up O-ring c during spool switching and causes it to escape from circumferential groove b. , as described above, the side walls of the outer circumferential grooves 12a, 12b of the spool 2 and the elastic ring 11
By providing a gap 13 between the sides of a and 11b, pressure fluid freely flows in the radial direction of the spool through the gap 13, and the elastic ring is pushed up by the fluid pressure. There is no such thing.

FIG. 4 shows another embodiment of the present invention, in which two elastic rings 11 each are used to reduce the travel distance of the spool required for sealing and releasing the fluid.
A, 11a and 11b, 11b are provided. Note that the other configurations are the same as in the case of FIG. 2, so the same parts are given the same reference numerals and the explanation thereof will be omitted.

Further, FIGS. 5A and 5B show the outer circumferential grooves 12a and 12b, respectively.
12b is shown, and FIGS. 6A to 6C show modifications of the elastic ring bodies 11a and 11b, respectively. In these cases, it is expected that the same effects as in the embodiment shown in FIG. 2 can be expected. can do.

In the above embodiment, the present invention has been described as being applied to a four-way switching valve, but it is of course applicable to various other spool valves.

[Brief explanation of the drawing]

Fig. 1 is a partially enlarged vertical sectional view of a conventional spool valve, Fig. 2 is a vertical sectional view of a spool valve of the present invention, Fig. 3 is a partially enlarged view, and Fig. 4 is a partially enlarged longitudinal sectional view of a conventional spool valve. FIGS. 5A and 5B are partial sectional views showing modified examples of the outer circumferential groove, and FIGS. 6A to 6C are longitudinal sectional views of the embodiment.
3A and 3B are partial cross-sectional views showing modified examples of the elastic ring body, respectively. 1... Valve case, 2... Spool, 11a, 11b
...Elastic ring body, 12a, 12b...Outer peripheral groove.

Claims (1)

[Scope of utility model registration request] It comprises a valve housing and a spool that is slidably inserted in the axial direction inside the valve housing, and an elastic ring body that contacts the inner wall of the valve housing to open and close the flow path opened in the inner wall is fitted into the outer circumferential groove of the spool. The width of the elastic ring body in the radial direction of the spool is larger than the thickness of the elastic ring body in the axial direction of the spool. A gap spanning the entire depth of the outer circumferential groove is formed between the spool and the side wall of the groove, and the inner circumference of the elastic ring body is fitted into the outer circumferential groove with the inner circumference of the spool in contact with the inner bottom of the outer circumferential groove. spool valve.