JPH07280110A - Three-port valve - Google Patents

Abstract

PURPOSE:To provide a three-port valve capable of preventing three ports from being communicated to one another. CONSTITUTION:This valve has a first port 4 and a second port 5 as faced to each other, and a third port communicated thereto. Also, valve rods 25a and 25b with valve discs 14a and 14b at the forward ends are slidably inserted in the chamber 24 of a piston 22 for driving the discs 14a and 14b to open and close the first port 4 and the second port 5. Engagement sections 26 for catching the opening periphery 24a of the chamber 24 are formed on the base ends of the rods 25a and 25b. Also, a spring 27 as compressed is laid between the engagement sections 26. As a result, even when one of the discs 14a and 14b opens a valve seat on the operation of the piston 22, the other closes the seat with a spring force, thereby preventing three ports from being communicated with one another.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a three-port valve that opens and closes two ports opened oppositely to each other by driving one piston.

[0002]

2. Description of the Related Art FIG. 2 shows a known three-port valve that opens and closes two ports opened oppositely to each other by driving one piston.
The valve body 2 has a first port 4 and a second port 5 which are opened so as to face each other in the axial direction, and these ports 4 and 5 are
The flow paths 7a and 7b communicate with the third port 6 of the adapter body 8 attached to the valve body 2. The valve body 2 has a through hole in a direction orthogonal to the axial direction,
Cylinder members 10a and 10 that are hermetically inserted in the through holes
A cylinder chamber in which the piston 11 slides is formed by b, and the flow passages 7a, 7b are formed in the valve chambers 12a, 12b formed between the valve body 2 and the cylinder members 10a, 10b.
b and the first valve seat 13a of the first port 4 and the second port 5
Also, the second valve seat 13b is open.

The first valve body 14a and the second valve body 14b, which open and close the first valve seat 13a and the second valve seat 13b, are constructed as diaphragm valves, and the peripheral edges of the valve body 2 and the cylinder members 10a and 10b. It is sandwiched between them. Piston 1
1 is formed integrally with the piston, and is a cylinder member 10
Piston rods 11a and 1 that hermetically penetrate through the holes a and 10b
1b, and the valve bodies 14a and 14b are attached to the tips of the piston rods 11a and 11b. The cylinder chamber is
The first drive chamber 15a and the second drive chamber 1 are driven by the piston 11.
The drive chamber is divided into 5b, and a first drive port 16a and a second drive port 16b for supplying and discharging the drive fluid for the piston are provided in these drive chambers.

FIG. 2 shows a case where the first port 4 and the second port 5 are pressure fluid supply ports and the third port 6 is a pressure fluid output port in the three-port valve 1.
The piston 11 moves upward in the drawing by the driving fluid supplied from the driving port 16b to the second driving chamber 15b,
The valve body 14a closes the first valve seat 13a to close the second valve body 14b.
Opens the second valve seat 13b. Therefore, the fluid in the second port 5 is output from the third port 6. The fluid in the second drive chamber 15b is discharged and the first drive port 1
When drive fluid is supplied from 6a to the first drive chamber 15a, the piston 11 moves downward in the figure and the second valve body 14b moves to the second
The valve seat 13b is closed so that the first valve body 14a becomes the first valve seat 13a.
Is opened, the fluid in the first port 4 is output from the third port 6.

However, since the piston rods 11a and 11b move integrally with the piston 11 in the three-port valve 1, the first valve body 14a is closed before the second valve body 14b closes the second valve seat 13b. The first valve seat 13a is opened to
The port 4 and the second port 5 temporarily communicate with the third port 6. Therefore, for example, the first port 4 and the second port 5
When the pressures of the fluids supplied to and differ from each other, there is a problem that the fluid in the high-pressure side port flows out to the low-pressure side port.

When the third port 6 is used as the pressure fluid supply port and the first port 4 and the second port 5 are used as the pressure fluid output ports, the movement of the piston 11 causes the first port 4 and the second port to move. 5 temporarily communicates with the third port 6, and the pressure fluid of the third port 6 is output to both the first port 4 and the second port 5, so that the response of the fluid equipment connected to these ports May deteriorate. further,
Since the two ports 4 and 5 facing each other cannot be closed together,
In either case, there is a problem that the supply of the pressure fluid cannot be stopped when an abnormal situation or the like occurs.

[0007]

SUMMARY OF THE INVENTION The problem to be solved by the present invention is to provide a three-port valve in which two pistons are driven by one piston, and the three ports do not communicate with each other. To do.

[0008]

In order to solve the above-mentioned problems, a three-port valve of the present invention has a first port and a second port opened opposite to each other, and a third port communicating with these ports. A valve body, a poppet-type first valve body and a second valve body that open and close the first port and the second port, and a piston that drives these valve bodies, and a first drive chamber and a second drive that are partitioned by the piston A three-port valve that drives a piston by driving fluid that is supplied to and discharged from a chamber to disconnect the first port and the second port from the third port, and the first valve that drives the first valve body and the second valve body At the base end portions of the rod and the second valve rod, locking portions for locking the opening edge of the chamber provided in the piston are provided, and these locking portions are inserted so as to be relatively movable in the chamber of the piston, A spring for biasing the locking portion toward the opening edge is contracted between these locking portions. It is characterized in that.

[0009]

When the drive fluid is not supplied to the two drive chambers partitioned by the piston, the spring contracted between the two valve rods provides the pistons with the locking portions of these valve rods. By pressing in the direction of coming into contact with the opening edge of the chamber, the valve elements attached to the respective valve rods close the corresponding valve seats. When the drive fluid is supplied to either one of the drive chambers, the piston and the valve rod on the drive chamber side move in the corresponding opening direction of the valve seat, so that the valve body on the drive chamber side to which the drive fluid is supplied is moved. Open the corresponding valve seat. In this case, since the valve rod on the opposite side is pressed in the closing direction of the valve seat by the urging force of the spring contracted between the valve rods, the valve body on the opposite side does not open the valve seat. When the drive fluid in the drive chamber is discharged, each valve body returns to the state in which the corresponding valve seat is closed by the urging force of the spring compressed between the valve rods. Therefore, since the two ports facing each other can be closed at the same time, the three ports do not communicate with each other.

[0010]

FIG. 1 shows an embodiment of the present invention. This 3-port valve 21 has the same construction as the above-mentioned known 3-port valve 1 except for a piston and a valve rod described below. ,
The same reference numerals are given to the same portions in the drawings, and detailed description will be omitted.

A piston 22 sliding airtightly in the cylinder chamber
Is a cup-shaped first piston member 23a having a recess
And a first piston member 23b attached to the first piston member by a screw covering the opening of the recess, and the recess forms a chamber 24. In this room 24,
An intermediate portion between the first valve rod 25a and the second valve rod 25b is airtightly and individually slidably inserted, and the base ends of the valve rods 25a and 25b are locked to the opening edges 24a and 24a of the chamber 24. Locking portions 26, 26 are formed, and the first valve body 1
4a and the 2nd valve body 14b are attached. Further, a coil spring 27 is urged between the base ends of the valve rods 25a and 25b to bias the locking portions 26, 26 toward the opening edges 24a, 24a, respectively. The valve rods 25a and 25b are
In the state shown in the drawing, which is separated by the biasing force of the spring 27,
Both the valve bodies 14a and 14b have a length capable of closing the valve seats 13a and 13b, and the locking portions 26, 26 and the opening edge 24.
A slight gap is formed between the a and 24a as shown in the figure.

In the above embodiment, the drive chambers 15a and 15b are
In the state shown in the drawing in which the compressed air as the driving fluid is not supplied, the valve rods 25a and
The locking portions 26 and 26 of 5b are separated from each other, and the first valve body 14a and the second valve body 14b close the first valve seat 13a and the second valve seat 13b. From the first drive port 16a to the first drive chamber 15a
When compressed air is supplied to the piston 11, the piston 11 descends in the figure, whereby the opening edge 24a of the chamber 24 engages with the engaging portion 26 of the first valve rod 25a and lowers the valve rod. The body 14a opens the first valve seat 13a. In this case, the second valve body 14b is pressed by the biasing force of the spring 27 in the direction of closing the second valve seat 13b, and thus the second valve seat 13b is closed.
b is closed. Therefore, the first valve seat 13a and the second valve seat 13a
The valve seat 13b does not open at the same time. First drive room 1
When the driving fluid of 5a is discharged, the first valve rod 25a and the piston 11 move upward in the drawing to return to the illustrated state by the urging force of the spring 27, so that the first valve body 14a moves to the first valve seat 1
Close 3a. Also in this case, the second valve body 14b does not open the second valve seat 13b.

From the second drive port 16b to the second drive chamber 15
When compressed air is supplied to b, the piston 11 moves upward in the figure and the second valve body 14b opens the second valve seat 13b. In this case as well, the first valve body 14a closes the first valve seat 13a by the urging force of the spring 27, so the first valve seat 13a
And the second valve seat 13b are never opened at the same time.

In the three-port valve 21 of the above embodiment, the first port 4 and the second port 5 are pressurized fluid (compressed air as an example).
In the case where the third port 6 is used as the pressure fluid output port, and when the third port 6 is used as the pressure fluid supply port and the first port 4 and the second port 5 are used as the pressure fluid output ports. In the above, even when one valve body opens the corresponding valve seat, the other valve body closes the corresponding valve seat by the urging force of the spring 27, so that compressed air temporarily flows backward. Alternatively, the compressed air does not temporarily flow out to the two ports. Further, since the first port 4 and the second port 5 can be closed at the same time, the supply of the pressure fluid can be stopped in any case.

The valve bodies 14a and 1 in the above embodiment are
Although 4b is a diaphragm valve, the valve element of the present invention is not limited to the diaphragm valve, and may be a poppet type valve element.

[0016]

According to the three-port valve of the present invention, the three ports do not communicate with each other even when the valve seats corresponding to the two valve bodies are opened and closed by the movement of the piston. Backflow and temporary outflow to two ports can be eliminated. Further, the two ports corresponding to the valve body can be simultaneously closed to stop the supply of the pressure fluid.

[Brief description of drawings]

FIG. 1 is a vertical sectional front view of an embodiment.

FIG. 2 is a vertical sectional front view of a known 3-port valve.

[Explanation of symbols]

 2 valve body 4 1st port 5 2nd port 6 3rd port 13a, 13b valve seat 14a, 14b valve body 15a, 15b drive chamber 21 3 port valve 22 piston 24 chamber 25a, 25b valve rod 26 locking part 27 coil spring

Claims (1)

[Claims] 1. A valve body having a first port and a second port opened opposite to each other, and a third port communicating with these ports, and a poppet-type first valve for opening and closing the first port and the second port. A body, a second valve body, and a piston for driving these valve bodies, and the piston is driven by a drive fluid supplied to and discharged from the first drive chamber and the second drive chamber partitioned by the piston,
In a three-port valve that disconnects the first port and the second port from the third port, a piston is provided at the base end portions of the first valve rod and the second valve rod that drive the first valve body and the second valve body. Providing locking parts for locking the opening edges of the provided chambers, these locking parts are inserted in the chamber of the piston so as to be relatively movable, and the locking parts are provided between the locking parts. A three-port valve characterized in that a spring for urging it toward is contracted.