JPH0220538Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a spool valve used in industrial machinery that utilizes fluid pressure.

[Prior Art] Conventionally, as shown in FIG. 6, a valve housing 1 is provided with a valve stem 2 slidably inserted in the axial direction inside the valve housing 1, and an input port 7 and an output port are provided on the inner wall of the valve housing 1. A valve seat 4 is provided between the valve stem 2 and the outer circumferential groove 5 of the valve stem 2.
The annular elastic valve body 6 fitted into the outer circumferential groove 5 is integrated with a mounting portion 6a that fits into the outer circumferential groove 5 and a bent portion 6b extending radially from the mounting portion.
b is formed by making the length in the radial direction larger than the thickness in the axial direction, and the valve body 6 is brought into contact with the valve seat 4 in the valve housing 1 by sliding from the output port 8 side, A spool valve that opens and closes between both ports is well known (for example, the Utility Model Opened in 1983).
-Refer to Publication No. 160362).

Since the valve body 6 has an elongated cross section in the radial direction, it is easily bent by sliding of the valve stem 2 and seals the valve seat 4. In order to prevent tilting due to fluid pressure etc. when sliding from the 8 side to the input port 7 side where fluid pressure is high and riding on the valve seat 4, a support wall 3 integrated with the valve stem 2 is provided behind it. Therefore, due to the sliding resistance caused by the contact with the valve seat 4 when the valve stem 2 slides, and the fluid pressure acting on the valve body 6, the tip of the bent portion 6b of the valve body 6 is brought into contact with the valve seat 4 and the support wall. It may be caught between 3.

This pinching of the valve body 6 increases the sliding resistance of the valve stem 2, which not only requires a large operating force, but also if the pinching is significant, the valve stem 2
There is a disadvantage that the valve body 6 becomes unable to slide or the valve body 6 is worn out.

[Problem to be solved by the invention] The problem to be solved by the invention is to prevent the valve body from being pinched between the valve seat and the valve stem by giving directionality to the bending of the valve body. points.

[Means for Solving the Problems] The present invention, in the above-mentioned known spool valve, forms a tapered surface at the end of the output port side of the valve seat on the inner wall of the valve housing, and forms a bent portion of the elastic valve body into a valve. The angle θ ₁ that the tapered surface makes with the axis, the angle θ ₂ that the bent portion inclines with respect to the plane perpendicular to the axis, and the sealing surface at the tip of the bent portion and the tapered surface. The angle θ ₃ is set to θ<θ ₁ ≦θ ₂ ≦45°, θ ₃ ≧0°, thereby solving the above problem.

[Operation] When the valve stem is slid from the output port side toward the valve seat, the sealing surface at the tip of the bent portion of the valve body comes into contact with the tapered surface of the valve seat and is pressed.

In this case, since the bent part is inclined toward the valve seat and the angle θ ₃ between the sealing surface of the bent part and the tapered surface is equal to or larger than the angle θ ₁ of the tapered surface, the valve body A force acts on the bent portion to incline it toward the input port, and this force prevents the bent portion from being pinched as described above. Bending of the bent portion toward the input port side due to the above force is easy because the length of the bent portion in the radial direction is made larger than the thickness in the axial direction so that the bent portion can be easily bent. be.

As the valve stem continues to slide, the sealing surface of the valve body comes into pressure contact with the valve seat, but since the valve body tends to tilt toward the input port due to the above bending, there is a gap between the valve seat and the supporting wall of the valve stem. Never get caught.

When the sealing surface comes into pressure contact with the valve seat, the bent portion receives a force in the direction of standing up due to the fluid pressure acting on the surface on the input port side, thereby reliably sealing the valve seat. Therefore, as the fluid pressure increases, the sealing force of the valve body also increases.

[Embodiment] Figures 1 and 2 show a first embodiment of the present invention, in which a valve stem 12 is inserted into a valve housing 11 of a spool valve so as to be slidable in the axial direction. 12 is
It is configured to be driven by electromagnetic operating force, mechanical operating force, or fluid pressure operating force acting on the end portion.

The valve housing 11 includes an input port 13 in the center of the valve housing,
Output ports 14a, 14b on both sides thereof, discharge ports 15a, 15b on both sides thereof, and inner circumferential grooves 16, ... communicating with these ports, and valve seats 17a, 17b,... on the inner wall of the valve casing between these inner circumferential grooves. 18
a, 18b, and an angle θ ₁ is formed at the end of each valve seat on the contact side of the valve body described later with respect to the cylindrical surface of the inner wall of the valve housing.
A tapered surface 19 is provided.

The valve stem 12 includes annular elastic valve bodies 20a, 21a that abut against the valve seats 17a, 18a, and the valve seat 1.
an annular elastic valve body 20b that abuts on 7b and 18b;
21b are fitted around the outer circumferential grooves 22, . . . .

In the drawings, the valve bodies 20a, 20b, 2
1a and 21b are all shown as having the same shape, but the problem here is that the input port 1
Valve seat 17 between 3 and output ports 14a, 14b
A valve body 20 that approaches and separates from the output port side on a and 17b
a, 20b, that is, the valve bodies that slide from the output port side where the fluid pressure is low to the input port side where the fluid pressure is high and ride on the valve seat.Therefore, the other valve bodies have the structure described below. Any suitable structure can be adopted without limitation.

The above-mentioned valve bodies, particularly the valve bodies 20a and 20b, contact the valve seat on the inner wall of the valve housing to open and close the flow path between the ports opened on the inner wall of the valve housing, and are made of an elastic material.
As shown in FIG. 2, it is constructed by integrating a mounting portion 23 fitted into the outer circumferential groove 22 and a bent portion 24 extending radially from one end of the mounting portion 23. A sealing surface 25 is formed at the tip of the valve 24 for contacting and sealing the valve seat.

The bent portion 24 is inclined toward the input port 13 by an angle θ ₂ with respect to a plane perpendicular to the axis of the valve stem 2, and the angle θ ₂ is made equal to or larger than the angle θ ₁ . , sealing surface 25 and tapered surface 19
By making the angle θ ₃ equal to or larger than the above-mentioned angle θ ₁ , that is, θ<θ ₁ ≦θ≦45° and θ ₃ ≧0°, the sealing surface 25 becomes the tapered surface 1.
9, the bent portion 24 is bent toward the mounting portion, that is, toward the input port 13. In addition, by making the radial length b of the bent portion 24 larger than the axial thickness a, the above-mentioned bending is facilitated.

In FIG. 2, the back surface of the bent portion 24 is inclined at an angle α with respect to the inner surface of the support wall forming the outer circumferential groove 22, but this angle may be 0°.

Next, the operation of the first embodiment will be explained.

The upper half of FIG. 1 shows the state in which the valve stem 2 is sliding;
The lower half shows the state in which sliding has been completed.

Before the valve stem 12 slides, the valve stem is located at the left end in the valve housing, and the valve bodies 20b, 21a are located at the valve seats 17b, 1.
8a is closed, and the valve bodies 20a and 21b are closed to the valve seat 17.
This is the state where a and 18b are open. In this state, when the valve stem 12 slides to the right in the figure with an appropriate operating force, the sealing surfaces 25 of the valve bodies 20a and 21b are pressed against the valve seat, as shown in the upper half of Fig. 1 and Fig. 2. 1
It is pressed against the tapered surfaces 19 of 7a and 18b.

In this case, the angle θ ₃ is equal to or greater than the angle θ ₁ , and the angle θ ₂ is equal to or greater than the angle θ ₁ , so that the valve body is in contact with the tapered surface 19. This causes the valve body 2 to receive a force that tilts toward the mounting portion, and in combination with the fact that the radial length b of the bent portion is larger than the axial thickness a, the valve body 2
The bent portion 24 of Oa is bent toward the attachment portion. Therefore, the valve body 20a is not pinched between the valve seat 17a and the valve stem.

When the valve stem 12 further slides to the right, as shown in the lower half of FIG.
Contact and seal. In this case, the valve body 20a,
Since the bent portion 24 of 21b receives a force in an upright direction due to the fluid pressure, the sealing surface 25 securely seals the valve seat, and the sealing force becomes stronger as the fluid pressure increases.

When the valve stem 12 slides to the left in the figure in this state, the flow path switches and returns to the original state, but the actions of the valve bodies 20b and 21a in this case are the same as in the above case, so please refer to the details below. Further explanation will be omitted.

Note that the spool valve of the present invention may be one that opens and closes a fluid flow path, and is of course not limited to the above-mentioned 5-port valve.

FIG. 3 shows a second embodiment of the present invention, in which a valve body 30
The sealing surface 32 of the bent portion 31 is a flat surface, and the angle θ ₃
is larger than 0°.

FIG. 4 shows a third embodiment of the present invention, in which the valve body 35
The sealing surface 37 of the bent portion 36 is provided closer to the mounting portion 23 than the central portion, and the angle θ ₃ is larger than 0°.

FIG. 5 shows a fourth embodiment of the present invention, in which a valve body 40
The sealing surface 42 of the bent portion 41 is the same as that in the first embodiment, but the surface on the back side of the bent portion in the outer circumferential groove 43 is sloped in the same way as the bent portion, and the outer surface of the bent portion 41 is aligned along this. A recess 44 is formed at the connection portion of the inner surface of the bent portion 41 with the attachment portion.

The bending portion 41 of the fourth embodiment can be bent more easily toward the mounting portion due to the above-described configuration.

The other structures and functions of the second to fourth embodiments are the same as those of the first embodiment, so the same or corresponding parts are denoted by the same reference numerals in the drawings, and detailed description thereof will be omitted.

[Effect of the invention] The present invention prevents the valve element from being caught between the valve seat and the valve stem by bending the bent portion of the elastic valve element toward the input port when the valve stem slides. So,
It is possible to prevent an increase in the sliding resistance of the valve stem and damage to the valve body.

Further, after opening and closing the flow path, the bending portion receives a force in the direction of standing up due to the fluid pressure acting on the bending portion, so that the sealing is reliable.

[Brief explanation of the drawing]

Fig. 1 is a vertical sectional front view of the first embodiment of the present invention, the upper half shows the valve stem in the process of sliding, the lower half shows the state when the valve stem has finished sliding, and Fig. 2 is the same as Fig. 1. 3 to 5 are enlarged sectional views of main parts of other embodiments of the present invention, and FIG. 6 is an enlarged sectional view of main parts of a conventional example. 11... Valve housing, 12... Valve stem, 17a, 17
b, 18a, 18b...valve seat, 19...tapered surface, 20a, 20b, 21a, 21b, 30, 3
5, 40...Valve body, 22...Outer circumferential groove, 23...Mounting portion, 24, 31, 37, 41...Bending portion, 2
5, 32, 37, 42... Seal surface.

Claims (1)

[Scope of Claim for Utility Model Registration] A valve seat consisting of a valve housing and a valve stem slidably inserted in the axial direction inside the valve housing, and located between an input port and an output port on the inner wall of the valve housing. The annular elastic valve body fitted into the outer circumferential groove of the valve stem is integrated with a mounting part that fits into the outer circumferential groove and a bent part extending radially from the mounting part. The bent portion is formed by making the length in the radial direction larger than the thickness in the axial direction, and the valve body is brought into contact with the valve seat by sliding from the output port side in the valve casing, thereby forming a connection between both ports. In the spool valve configured to open and close, a tapered surface is formed at the end of the inner wall of the valve housing on the output port side of the valve seat, the bent portion of the elastic valve body is inclined toward the valve seat side, and the tapered surface is The angle θ ₁ made with the axis, the angle θ ₂ that the bent portion inclines with respect to the plane perpendicular to the axis, and the angle θ ₃ made between the sealing surface at the tip of the bent portion and the tapered surface.
A spool valve characterized in that θ<θ ₁ ≦θ ₂ ≦45° and θ ₃ ≧0°.