JPH0440052Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to an improvement of a three-way valve installed in a piping flow path to control the flow of fluid.

[Conventional technology]

Conventionally, as a three-way valve for switching or blocking the direction of a flow path, for example, one shown in FIG. 3 is known (see Japanese Utility Model Application Publication No. 15226/1983).

[Problems to be Solved by the Invention] The conventionally known three-way valve described above has first and second valves that are slidable relative to the valve rod 100 and are biased toward opposite sides in the axial direction by a spring 103. Second valve body 1
01, 102 are opened and closed relative to the valve holes 107, 108 by abutment with the engaging protrusions 104, 105 provided on the valve rod 100 on both sides in the axial direction. It is necessary to lengthen the stroke of the cylinder 106, and the valve bodies 101 and 10 until they abut against the engagement protrusions 104 and 105.
2 does not open, and the flow path is switched once both valve holes 10
Because it is done after passing through 7,108 cutoff states,
Responsiveness was also low. In addition, this three-way valve cannot have the function of blocking both flow paths in addition to the flow path switching function unless the cylinder 106 is structured to be able to stop in three positions: forward end, return end, and intermediate position. Therefore, a shutoff valve had to be used together.

[Means for solving problems]

In order to solve such problems, the three-way valve according to the present invention includes a cylinder, a first valve seat provided coaxially with the cylinder, a first valve seat on the side of the cylinder, and a second valve seat on the side opposite to the cylinder. a first piston on the valve chamber side and a second piston on the opposite valve chamber side arranged in the cylinder, the first piston facing the valve chamber side and the second piston facing the opposite valve chamber side. a pressure inlet port opened in each of the cylinders, a first valve body disposed in the valve chamber that approaches and separates from the first valve seat, and a second valve body that approaches and separates from the second valve seat. and,
a hollow stem that connects the first piston and the first valve body; a small diameter stem that is inserted through the hollow stem so as to be movable in the axial direction and connects the second piston and the second valve body; The valve valve includes a spring that keeps the pistons apart from each other and constantly biases both the valve bodies in a direction toward each other.

[Effect]

According to the three-way valve of the present invention, the first and second valve bodies are normally elastically restrained from each other by the biasing force of a spring, so that the first piston in the cylinder faces the valve chamber side or the second valve body. By pressurizing the side of the piston opposite to the valve chamber, both pistons and both valve bodies move together through the hollow stem and its small inner diameter stem, and either of the first and second valve seats is moved. or shut off one side and open the other side. Further, when both the pistons are moved toward each other against the biasing force of the spring by pressurizing both the valve chamber side of the first piston and the opposite valve chamber side of the second piston, both valve chambers The body moves in a direction of relative separation to block both valve seats.

〔Example〕

Below, the three-way valve according to the present invention is shown in Figures 1 and 2.
This will be explained with reference to an embodiment shown in the drawings.

In both figures, a cylinder 1, a bonnet 2, and a body 3 having a valve chamber 10 therein are coaxially arranged and integrally and airtightly connected to each other. First and second pistons 4 and 5 are respectively disposed airtightly and movably in the axial direction on the inner periphery of the cylinder 1. a lower space 6,
Facing the upper space 7 of the upper second piston 5,
Compressed air supply ports 8 and 9 are pressure introduction ports, respectively.
has been established.

A first valve seat 18 is provided on the upper side of the valve chamber 10, that is, on the cylinder 1 side, and a second valve seat 1 is provided on the lower side.
A first port 11 is formed between both valve seats 18 and 19, a second port 12 is formed above the first valve seat 18, and a second port 12 is formed below the second valve seat 19. The third ports 13 are each open. Also, inside the valve chamber 10, a first valve body 14 that comes into contact with and separates from the first valve seat 18 at the soft seat 15, and a second valve body that comes into contact with and separate from the second valve seat 19 at the soft seat 17. 16 are arranged.

The first valve body 14 is connected to the lower first piston 4 in the cylinder 1 via a hollow stem 21 inserted into the shaft hole 20 of the bonnet 2, and the second valve body 16 is connected to the first piston 4 on the lower side inside the cylinder 1. It is connected to the upper second piston 5 in the cylinder 1 via a small-diameter stem 22 that is slidably inserted into the hollow stem 21 . A coil spring 23 is installed between the first and second pistons 4 and 5 in a suitably compressed state, and the coil spring 23 presses the first and second pistons 4 and 5 in a direction that separates them from each other. And the second valve bodies 14 and 16 are constantly urged in a direction to bring them closer together. 24 is both pistons 4 and 5
This is a vent hole for allowing atmospheric air to enter and exit the space 25 between the pistons 4 and 5, which expands and contracts when the pistons move toward or away from each other.

A bellows 26 is provided between the valve bodies 14 and 16, and a bellows 26 is provided between the bonnet 2 and the valve body 14 in the shaft hole 20.
A bellows 27 is installed between the valve chamber 10 and the fluid flowing through the valve chamber 10 into the gap between the hollow stem 21 and the small diameter stem 22 or between the hollow stem 21 and the shaft hole 20. This is sealed to prevent leakage into the external space or into the cylinder 1 through the gap.

According to the three-way valve configured as described above, when compressed air is supplied from the upper compressed air supply port 9 to the upper space 7 of the second piston in the cylinder 1, and the lower compressed air supply port 8 is opened to the atmosphere, As shown in FIG. 1, the second piston 5 moves downward under the pressure of the compressed air in the upper space 7, and the first piston 4 also moves downward via the coil spring 23. Due to the downward movement of both pistons 4 and 5, the first and second valve bodies 14 and 1 are
6 are pushed down together, the first valve body 14 is separated from the first valve seat 18, and the second valve body 16 is seated on the second valve seat 19. Therefore the first port 11
and the second port 12 is allowed to flow between the first port 11 and the second port 1.
2 and the third port 13 is blocked.

Conversely, compressed air is supplied from the lower compressed air supply port 8 to the lower space 6 of the first piston 4 in the cylinder 1, and the upper compressed air supply port 9
When opened to the atmosphere, the first piston 4 moves upward under the pressure of the compressed air in the lower space 6, and the second piston 5 also moves upward via the coil spring 23. Due to the upward movement of both pistons 4, 5, both the first and second valve bodies 14, 16 are pulled up via the stems 21, 22, and the first valve body 14 is seated on the first valve seat 18, Second valve body 16
is spaced apart from the second valve seat 19. Therefore, fluid flow between the first port 11 and the third port 13 is allowed, and fluid flow between the first port 11 and the third port 13 and the second port 12 is allowed. flow is blocked.

The above two operations function as a flow path switching function in normal use, but if compressed air is supplied into the cylinder 1 from both compressed air supply ports 8 and 9, the three-way valve will function as a shutoff valve. It functions as a. That is, as shown in FIG. 2, in response to the pressure of compressed air from the compressed air supply ports 8 and 9,
When both pistons 4 and 5 move toward each other against the biasing force of the coil spring 23, the first valve body 14 is pulled up by the first piston 4 via the hollow stem 21, and the first valve body 14 is pulled up by the first piston 4 through the hollow stem 21. The second valve body 16 is pushed down by the second piston 5 via the small diameter stem 22 and is seated on the second valve seat 19 . Therefore, all fluid flows via the first to third ports 11, 12, 13 are blocked at the same time.

[Effect of idea]

As is clear from the above description, the three-way valve according to the present invention can arbitrarily operate the first and second valve bodies in the same direction or in the direction of separating them from each other. It has the function of both a shutoff valve, and the first and second valve bodies are inserted into the first and second pistons in the same cylinder through a hollow stem that is relatively movable in the axial direction and its inner periphery. They are connected via a small-diameter stem and can operate independently of each other, resulting in good responsiveness.Moreover, since the operation of each valve body is shared between the first and second pistons, the stroke does not become long. It has a great effect.

[Brief explanation of the drawing]

Fig. 1 is a sectional view of an embodiment of the three-way valve according to the present invention during flow path switching operation, Fig. 2 is a sectional view of the same during flow path blocking operation, and Fig. 3 is a schematic configuration of a conventional three-way valve. FIG. 1...Cylinder, 4...First piston, 5...
...Second piston, 8, 9...Compressed air supply port (pressure introduction port), 10...Valve chamber, 11...First port, 12...Second port, 13...Third port , 14...first valve body, 16...second valve body, 18...first valve seat, 19...second valve seat,
21...Hollow stem, 22...Small diameter stem, 23
...Coil spring.

Claims (1)

[Scope of utility model registration request] a cylinder, a valve chamber provided coaxially with the cylinder and having a first valve seat on the side of the cylinder and a second valve seat on the side opposite to the cylinder; and a first valve seat on the side of the valve chamber arranged in the cylinder. a second piston on the side opposite to the valve chamber; a pressure introduction port opened in the cylinder facing the valve chamber side of the first piston and a side opposite to the valve chamber of the second piston; a first valve element that approaches and separates from the first valve seat; a second valve element that approaches and separates from the second valve seat; and a hollow space that connects the first piston and the first valve element. a small-diameter stem that is inserted into the hollow stem so as to be axially movable and connects the second piston and the second valve body; A three-way valve characterized by comprising: a spring that is constantly energized;