JPH0562274B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to an air-operated valve, which controls the supply of fluid to various purpose devices operated using fluid, and which is biased in a certain direction. Due to the biasing force of the piston, the valve part provided on the piston keeps the fluid flow path open or closed at all times, and also senses abnormal pressure of the fluid and applies air pressure to the piston against the biasing force. A normally open air-operated valve and a normally closed air-operated valve, which change the fluid flow passage from a normally open state to a closed state or from a normally closed state to an open state, by having some parts assembled in different directions. This makes it possible to mold parts with the same shape and size.

Conventional technology Conventional air-operated valves use the biasing force of a piston that is biased in a certain direction to constantly open a fluid flow path in a valve section provided on the piston, and also sense abnormal pressure of the fluid and apply air pressure. A normally open air-operated valve changes the fluid flow path from normally open to closed by applying force to the piston, and a normally open air-operated valve changes the fluid flow path from normally open to closed by applying force to the piston, and a valve part provided on the piston that normally controls fluid flow by the biasing force of the piston. There is a normally closed air-operated valve that constantly closes the fluid flow path and senses abnormal fluid pressure and applies air pressure to the piston against a biasing force, thereby changing the fluid flow path from normally closed to open. do.

Although the normally open air operated valve and the normally closed air operated valve among these air operated valves have some parts in common,
Most of them are made of members with different shapes and dimensions, so they cannot be used in common, resulting in a large number of parts and a lack of commonality, which requires time and effort to assemble.

Problems to be Solved by the Invention The present invention relates to an air-operated valve that eliminates the above-mentioned drawbacks, and includes a normally open air-operated valve and a normally closed air-operated valve. Same shape,
A normally open air-operated valve and a normally closed air-operated valve can be configured by forming the valves with the same dimensions and simply attaching some parts in different directions, greatly reducing the number of parts. At the same time, it is possible to obtain a pneumatically operated valve at low cost and with high productivity because the assembly method, procedure, etc. are common.

Means for Solving the Problems In order to solve the above-mentioned problems, the present invention uses the biasing force of the piston that is biased in a certain direction by a pressing spring to constantly maintain a fluid flow path through a valve portion provided on the piston. By sensing abnormal pressure of the fluid and applying air pressure to the piston against the biasing force, the fluid flow passage can be changed from normally open to closed state or from normally closed to open state. A control air inlet is formed on the axial side surface of the casing on which the piston is slidably mounted, and a control air inlet is formed on the inner peripheral surface of the casing from the center of the piston's outer periphery in the thickness direction toward the pressing side of the pressing spring. It is formed by forming a seal portion that makes airtight contact.

Effect Since the present invention is configured as described above,
In a normally open air-operated valve, the biasing force of the piston keeps the fluid flow path open at the valve part connected to the piston, and if abnormal fluid pressure is detected, air pressure is applied to resist the biasing force. By applying this to the piston, the fluid flow path is changed from normally open to closed. In addition, in the case of a normally closed air-operated valve, the biasing force of the piston causes the valve section connected to the piston to always close the fluid flow passage, and when abnormal pressure of the fluid is detected, the air pressure is applied against the biasing force. By applying the fluid to the piston, the fluid flow path is changed from a closed state to an open state. In addition, air-operated valves are
A control air inlet is formed on the axial side surface of the casing in which the piston is slidably mounted, and an air-tight inlet is formed on the inner peripheral surface of the casing from the center of the piston's outer periphery in the thickness direction toward the pressing side of the pressing spring. Since it forms a contacting seal, when assembling the piston to the piston rod, if the piston is installed in the correct position, the seal can be positioned in one direction from the inlet, so it can be positioned in one direction from the inlet to the other. Control air can flow into one side of the piston in one direction, and when the piston is assembled in the reverse position, the seal part can be positioned in the other direction from the inlet. On the other hand, it allows control air to flow in, and by simply changing the direction in which the piston is assembled to the piston rod, a normally open air-operated valve and a normally closed air-operated valve can be constructed from the same member. It is something that can be done.

Embodiment An embodiment in which the present invention is applied to a normally open air-operated valve will be described below with reference to FIG.
A control air inlet 3 is formed on the axial side surface of the casing 2, and a control air inlet 3 is formed on the axial side of the casing 2. A seal portion 5 that airtightly contacts the peripheral surface is formed by an O-ring, and an annular insertion recess 6 is formed from one end surface 4 side where this seal portion 5 is formed. The piston 1 is urged in a certain direction by a pressing spring 8 interposed between the insertion recess 6 and the main body 7, and the piston 1 is fixed to a piston rod 10 via a fixing ring 11. In this state, the seal portion 5 is on the side pressed by the pressing spring 8 rather than the injection port 3, that is, the main body 7
When control air is injected from the injection port 3 located on the side, the control air presses the piston 1 through the introduction path 12 formed in the space between the inner surface of the casing 2 and the outer circumference of the piston 1, and absorbs the restoring force of the spring 8. The piston 1 is moved by flowing in the direction of pushing against the pressure. Further, the casing 2 is rotatably fixed to the main body 7 by connecting and fixing one end to the main body 7 via a lock ring 13. Also, on the inner periphery of the main body 7,
A connecting body 15 having a control fluid flow path 14 is screwed and fixed via a threaded portion 16, and the piston rod 10 is inserted into the connecting body 15, and a valve portion 17 provided at an end of the piston rod 10 is inserted into the connecting body 15. It is located facing the opening/closing part 18 of the passage 14 so that the flow passage 14 is not normally closed. Further, the outer periphery of the piston rod 10 is partially covered with a bellows 20 to protect it from being corroded by the control fluid flowing through the flow passage 14. In addition, gas intake and exhaust ports can be formed on the side surface of the casing 2 on the pressure spring 8 side as the piston 1 moves forward and backward, but this is not necessarily necessary when the piston 1 has a short sliding distance. Must not be.

In the structure configured as described above, the valve portion 17 of the piston rod 10 is normally connected to the flow path 1 of the control fluid due to the biasing force applied to the piston 1 by the pressing spring 8.
4 is kept open at all times and when abnormal pressure of the control fluid is detected, air pressure is applied to the piston 1 from the inlet 3 through the introduction path 12 against the biasing force, thereby causing the valve portion 17 to Opening/closing part 1 of the flow path 14
Close 8.

In the above embodiment, an embodiment in which the present invention is used as a normally open air operated valve has been described. However, when the present invention is used as a normally closed air operated valve, the fixing of the piston 1 to the piston rod 10 is This is reversed from the case of a normally open air-operated valve, and when the sealing member 5 is fixed to the piston rod 10 via the fixing ring 11, the sealing member 5 is located on the side pressed by the pressure spring 8 rather than the inlet 3, that is, on the side of the casing 2. Top plate 21
The valve part 17 is located on the side, and the valve part 17 is connected to the opening/closing part 18 of the flow passage 14.
By always pressing the valve closed, it can be used as a normally closed air-operated valve. This normally closed air-operated valve senses abnormal pressure of the fluid, and when control air is injected from the inlet 3, it passes through the introduction path 12 formed between the inner surface of the casing 2 and the outer circumference of the piston 1. The control air flows into the main body 7 side and pushes the piston 1 toward the top plate 21 of the casing 2 against the restoring force of the pressing spring 8 inserted between the piston 1 and the top plate 21 of the main body 7. As a result, the fluid flow path 14 is changed from the closed state to the open state.

Also, the insertion interval of the pressing spring 8 when the piston 1 is installed in the normal position on the piston rod 10, that is, in the state of the normally open air operated valve, and the insertion interval of the pressing spring 8 when the piston 1 is installed on the piston rod 10 in the reverse position, that is, the normally closed air operated valve state. The insertion interval of the pressing springs 8 in the valve state is approximately the same size, and the pressing springs 8 used are
Also, the normally open air operated valve and the normally closed air operated valve are formed so that the same size and shape can be used. However, depending on the target control pressure of the control fluid, the inflow pressure of the fluid into the introduction passage 12, etc., there may be cases where different pressure springs are used for the normally open air operated valve and the normally closed air operated valve. Of course.

Effects of the Invention As described above, when assembling the piston to the piston rod, when the piston is assembled in the correct position, the sealing member can be positioned in one direction from the inlet. Control air can flow into one side of the piston, and when the piston is assembled in an inverted position, the seal part can be positioned in the other direction from the inlet, so the other side of the piston in one direction from the inlet It is now possible to allow control air to flow in, and by simply changing the direction in which the piston is assembled to the piston rod, a normally open air operated valve and a normally closed air operated valve can be configured with the same member. This allows for a significant reduction in the number of parts compared to conventional products, as well as improved assembly methods and procedures.
It is possible to obtain a pneumatically operated valve with a lot of commonality and high productivity at low cost.

[Brief explanation of drawings]

The drawings show an embodiment of the present invention, and FIG. 1 is a sectional view when the invention is used in a normally open air-operated valve, and FIG. 2 is a sectional view when it is used in a normally-closed air-operated valve. DESCRIPTION OF SYMBOLS 1... Piston, 2... Casing, 3... Inlet, 4... One end surface, 5... Seal portion, 8... Pressing spring, 10... Piston rod, 14... Flow path, 13... Lock ring, 17... Benbe.

Claims (1)

[Scope of Claims] 1. By the urging force of the piston that is urged in a certain direction by a pressure spring, a valve section provided on the piston always opens or always closes a fluid flow passage, and also senses abnormal pressure of the fluid. A casing on which a piston is slidably attached is used to change a fluid flow passage from a normally open state to a closed state or from a normally closed state to an open state by applying air pressure to the piston against a biasing force. A control air inlet is formed on the axial side surface, and a seal portion is formed from the center of the piston's outer periphery in the thickness direction toward the pressing side of the pressing spring to airtightly contact the inner peripheral surface of the casing. Air operated valve. 2. Claim 1, characterized in that the casing is rotatable relative to the main body.
Air-operated valves as described in section. 3. The air-operated valve according to claim 2, wherein the casing is rotatably fixed to the main body via a lock ring.