JPH0123003Y2 - - Google Patents

Description

[Detailed Description of the Invention] Industrial Application Field The present invention relates to an improvement of a three-way switching valve.

BACKGROUND ART In recent years, there has been a demand to prevent compressed air containing oil mist from being discharged into the working environment, and in this case, air cleaning equipment such as a filter is connected to the exhaust port of the valve. In order to connect these devices, it is necessary to open the exhaust port in the valve body with a thread for connecting the devices.

As a three-way switching valve having such an exhaust port provided in the body, the one shown in FIG. 4 is in practical use. In the figure, 1 is a body, and an input port 2 and an output port 3 are provided in the body 1.
and an input valve seat 5a that communicates with the exhaust port 4 and the valve chamber 1a, an input valve seat 5a that communicates the input port 2 and the output port 3 in the valve chamber 1a, and an exhaust valve seat that communicates the output port 3 and the exhaust port 4. 5b, and a push rod 6 for opening and closing each of the valve seats 5a, 5b is slidably inserted into the valve chamber 1a in the axial direction with one end thereof protruding outside. . The push rod 6 has a pair of valve seats 5a, 5
Input valve body 7a and exhaust valve body 7 which alternately open and close b.
b, and is biased by a return spring 8 contracted between the push rod 6, its flange 6a, and the body 1 in a direction in which one end thereof protrudes to the outside, and the input valve seat 5a is
When the input valve seat 5a is opened and the exhaust valve seat 5b is closed, the input valve seat 5a is opened and the exhaust valve seat 5b is closed. It is configured so that

However, in the switching valve with the above configuration,
The input valve body 7a and the exhaust valve body 7b are a pair of valve seats 5a,
5b cannot be closed at the same time, it is possible to prevent the input valve seat 5a and the output valve seat 5b from opening simultaneously and the fluid blowing from the input port 2 to the exhaust port 4 in the process of switching the fluid flow path. especially if the valve switching action is not fast.
This is economically unfavorable due to fluid loss.

In addition, a branch flow path opening/closing valve that is equipped with a pair of valve seats and valve bodies, and in which one valve body closes the valve seat and the other valve body opens the valve seat is disclosed in Japanese Patent Publication No. 58-58542. Proposed.

The previously proposed on-off valve has one valve seat as an input valve seat and the other valve seat as an exhaust valve seat.
It is possible to prevent blow-through between the input port and the exhaust port, but by making the pair of valve bodies both poppet-shaped, the pressing part and the exhaust valve body can be slid relative to each other, and the push rod return spring is separate. Since a spring is required to press the exhaust valve body against the valve seat, there is a problem that the valve structure is complicated and expensive.

Problems to be Solved by the Invention The present invention has a simple configuration in the three-way switching valve in which the exhaust port is provided in the body as described above.
In addition, the input valve body and the exhaust valve body are designed to be able to take a position that simultaneously closes the input valve seat and the exhaust valve seat, so that the input valve seat and the exhaust valve seat simultaneously open during the switching process of the fluid flow path. The technical challenge is to be able to prevent this from occurring.

Means for Solving the Problems In order to solve the above problems, in this invention,
An input port, an output port, and an exhaust port drilled in the body communicate with the valve chamber, and an input valve seat communicates the input port with the output port, and an exhaust valve communicates the output port with the exhaust port within the valve chamber. In the case where the input valve seat is formed respectively, a poppet input valve element that opens and closes the input valve seat from the input port side is urged toward the input valve seat by a valve element return spring, and the input valve element is urged toward the input valve seat by a valve element return spring. A push rod with a tapered tip that is pressed to open the valve against the urging force is inserted into the valve chamber with the other end protruding outside due to the urging force of the push rod return spring, and the push rod is inserted through the exhaust valve seat. an exhaust valve element configured with an O-ring fitted into the inner surface of the through hole, and inscribed in the exhaust valve seat to open and close the exhaust valve seat when the tip of the push rod and the input valve element are separated from each other; We have adopted the technical means of establishing a department.

Function When the push rod is pressed, the exhaust valve seat, which is made up of an O-ring fitted on the inner surface of the through hole through which the push rod is inserted, is closed by the exhaust valve body around the push rod, and then the push rod closes the input valve body. Drive to open and close the input valve seat.
Therefore, switching of the fluid flow path is performed without causing blow-through.

In this case, the exhaust valve seat is configured with an O-ring fitted into the through hole through which the push rod is inserted, and the push rod itself is provided with an exhaust valve body, allowing for three-way switching to prevent blow-through. The valve can be made simple and inexpensive.

When the pressure on the push rod is released, the push rod and input valve body return to their original states due to the biasing force of the return spring.
In this case as well, the exhaust valve element opens the exhaust valve seat after the input valve element closes the input valve seat, so blow-through does not occur.Moreover, by tapering the tip of the push rod, the exhaust valve element is attached to the push rod. Even if it is provided, it will not hinder the opening of the exhaust valve seat.

Effects of the invention According to the switching valve of the present invention, by making slight modifications to the conventional switching valve, it is possible to provide a product with a simple configuration and at low cost that does not cause blow-through when switching the fluid flow path. can.

Embodiments Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

1 and 2 show different switching states of the embodiment of the present invention, in which the input port 16, the output port 17, and the exhaust port 18 formed in the body 19 are respectively communicated with the valve chamber 19a. Input port 16 is formed by forming a female thread for piping connection in the port, and by applying mechanical operating force to push rod 20 with one end protruding outside from body 19, the flow path between the ports can be changed. The exhaust port 18 is configured to perform this without causing any blow-through between the exhaust port 18 and the exhaust port 18.

That is, the body 19 includes a valve seat body 22 that is fitted and fixed within the valve chamber 19a, and through holes 22a and 22b are bored in the valve seat body 22 in the axial and radial directions.
An input valve seat 23 is formed at one end of the through hole 22a to communicate the input port 16 and the output port 17, and an O-ring 26 is fitted and fixed in the through hole 22a to connect the output port 17 and the exhaust port. 1
8 is formed with an exhaust valve seat 24 that communicates with the exhaust valve seat 24.

The input valve seat 23 is a poppet input valve body 2 disposed displaceably in the axial direction on one end side within the valve chamber 19a.
7 toward the input port by the valve body return spring 28, the push rod is closed, and the push rod has a tapered tip and is disposed on the other end side of the valve chamber 19a so as to be movable in the axial direction. 20, the input valve body 27 is opened by driving it against the biasing force of a valve body return spring 28. The push rod 20 has a push rod return spring 31
is urged in a direction away from the valve seat body 22 by
An operating section 32 protruding outward from the body 19 at one end
and a cylindrical exhaust valve body part 34 that opens and closes the exhaust valve seat 24, a tip drive part 35 that drives the input valve body 27, and a taper part 36 that connects them, with a flange 33 for preventing slippage in between. It is prepared.

Further, the exhaust valve body portion 34 is configured to be tightly fitted into and removed from the O-ring 26 to open and close the exhaust valve seat 24, and to be able to slide within the O-ring 26 in the closed state. The length of the body part 34 and the tip drive part 35 is such that the exhaust valve body part 34 closes the exhaust valve seat 24 when the tip drive part 35 and the input valve body 27 are separated and the input valve seat 23 is closed. It is set to length.

In the three-way switching valve configured as described above, as shown in FIG. The exhaust valve body portion 34 of the push rod 20 is pulled out from the O-ring 26 by the biasing force of the push rod return spring 31, thereby opening the exhaust valve seat 24.
Therefore, the fluid in the output port 17 is transferred to the exhaust port 18.
is discharged to the outside through.

In this state, a mechanical operating force is applied to the operating portion 32 of the push rod 20, and the return springs 31, 28
When the push rod 20 is driven as shown in FIG. 2 against the urging force of will be closed. In this state immediately after closing, since the tip driving portion 35 of the push rod 20 has not yet reached the input valve body 27, a fully closed state is adopted in which all ports are closed. Thereafter, when the exhaust valve body part 34 of the push rod 20 is further pushed in while sliding tightly inside the O-ring 26, the tip drive part 35 eventually comes into contact with the poppet input valve body 27, and the valve The input valve seat 23 is opened by driving the body 27 against the biasing force of the valve body return spring 28, thereby switching between the input port 16 and the exhaust port 18 without blowing through.

When the mechanical operating force applied to the push rod 20 is removed in the state shown in FIG. It comes into contact with the input valve seat 23 and closes the valve seat 23. After this, only the push rod 20 continues to return by the push rod return spring 31, and when the exhaust valve body 34 is pulled out from the O-ring 26, the output port is closed. 17 and exhaust port 18 communicate with each other. Due to this communication, the fluid in the output port 17 is discharged to the outside via the exhaust port 18. Naturally, even in this switching process, blow-through between the input port 16 and the exhaust port 18 does not occur.

FIG. 3 shows a spool type switching valve using a different embodiment of the present invention as a pilot valve, 41 is a pilot valve, 42 is a spool type main valve, and the pilot valve 41 is the three-way switching valve of the above embodiment. The difference from the valve is that the body of the pilot valve is constructed by combining two body pieces 43 and 44, and that one body piece 44 houses a piston 46 for driving the spool 45 of the main valve 42. , the pilot input port 47 is connected to the main valve 42.
The input port 47 is connected to the supply port 52 of the main valve 42 through the pilot supply passage 51, and the pilot output port 48 is opened at a position in contact with the body 50 of the main valve 42. The exhaust port 49 is opened to the pilot chamber 55 by a passage 56, and a breathing chamber 58 defined inside the piston 46 is opened by a breathing passage 59 bored through the body pieces 43, 44 and the body 50.
The other configuration is substantially the same as the three-way switching valve shown in FIGS. 1 and 2, and the same reference numerals are given to the same parts and the explanation thereof will be omitted.

The pilot valve 41 thus operates in substantially the same manner as the three-way switching valve.

Further, in the main valve 42, 53a, 53b
is an output port, 54a, 54b are exhaust ports, 6
1 is a main valve return fluid supply path, 62 is a main valve return pressure chamber, and 63 is a return spring. 45
It moves by overcoming the combined force of the urging force of the return spring 63 acting on the other end and the fluid force of the main valve return pressure chamber 62, and switches the flow path between each port in the main valve 42.

[Brief explanation of the drawing]

Figures 1 and 2 are cross-sectional views showing different switching states of the embodiment of the present invention, Figure 3 is a cross-sectional view of a switching valve using a different embodiment of the present invention, and Figure 4 is a cross-sectional view of a conventional example. It is. 16,47...Input port, 17,48...Output port, 18,49...Exhaust port, 19,5
0...Body, 19a, 57...Valve chamber, 20...
Push rod, 23...Input valve seat, 24...Exhaust valve seat, 2
7...Poppet valve body, 28...Return spring,
34...Exhaust valve body part.

Claims (1)

[Scope of utility model registration request] An input port, an output port, and an exhaust port drilled in the body communicate with the valve chamber, and an input valve seat communicates the input port with the output port, and an exhaust valve communicates the output port with the exhaust port within the valve chamber. In the case where the input valve seat is formed respectively, a poppet input valve element that opens and closes the input valve seat from the input port side is urged toward the input valve seat by a valve element return spring, and the input valve element is urged toward the input valve seat by a valve element return spring. A push rod with a tapered tip that is pressed to open the valve against the urging force is inserted into the valve chamber with the other end protruding outside due to the urging force of the push rod return spring, and the push rod is inserted through the exhaust valve seat. an exhaust valve element configured with an O-ring fitted into the inner surface of the through hole, and inscribed in the exhaust valve seat to open and close the exhaust valve seat when the tip of the push rod and the input valve element are separated from each other; A three-way switching valve characterized by having a section.