JPH0510459A - Pneumatic valve - Google Patents

Abstract

PURPOSE:To save a space for mounting by integrally forming a large diameter valve and a small diameter valve inside a casing and providing them with variable orifice function. CONSTITUTION:A pneumatic valve possesses a construction wherein a small diameter valve 1 is enclosed inside a large diameter valve 3 which reciprocates inside a casing 4. Both valves are set in a closed state at first, then the small diameter valve 1 becomes open by ejecting valve driving high pressure air 8 from an air port 7 for opening, and a small quantity of gas flows from the IN port of the pneumatic valve to the OUT port. Next, the large diameter valve 3 becomes open by switching the valve driving high pressure air 8 from an air port 6 for closing to an air port 5 for opening, and a large quantity of gas flows from the IN port to the OUT port of the pneumatic valve.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pneumatic valve used in vacuum equipment, and more particularly to a valve opening / closing mechanism.

[0002]

2. Description of the Related Art Conventionally, a pneumatic valve for opening and closing an exhaust line, which is attached to a vacuum exhaust line connecting a vacuum container and a vacuum pump, has a valve 11 and a casing 4, as shown in the sectional view of FIG. It consists of an opening air port 5 for introducing the valve driving high pressure air 8 and a closing air port 6, and the valve is closed by introducing the valve driving high pressure air 8 into the closing air port 6. Further, the cross-sectional view of FIG. 2B shows that the valve is in the open state by switching the valve driving high pressure air 8 introduced from the closing air port to the opening air port.

[0003]

Since this conventional pneumatic valve can operate only either fully open or fully closed, in order to control the gas flow rate passing through the pneumatic valve, it is necessary to separate it from the pneumatic valve. It was necessary to install a variable orifice or add a pipe with different conductance and a pneumatic valve for opening and closing the pipe in another system. Therefore, when trying to change the pneumatic valve, which has been conventionally installed, to the variable orifice type, there was a problem in that it could not be installed due to the problem of the installation space, or a large modification was required to change the installation of the pipe.

[0004]

A pneumatic valve of the present invention is provided with a large-diameter valve that reciprocates by switching high-pressure air in a casing, and the large-diameter valve contains a small-diameter valve. It operates by high pressure air independently of the large diameter valve, and has a structure in which the small diameter valve is opened to control the flow rate during the closing operation of the large diameter valve.

[0005]

The present invention will be described below with reference to the drawings. FIG. 1 is a sectional view of a pneumatic valve according to an embodiment of the present invention, and FIGS. 1 (a), 1 (b) and 1 (c) respectively show the operation flow.

First, FIG. 1A shows a completely closed state in which a small diameter valve 1 is built in a large diameter valve 3 in a casing 4, and the large diameter valve 3 is driven by a closing air port 6 from a valve. The high-pressure air 8 for use is introduced into the closed state, and the small-diameter valve 1 is also closed by introducing the high-pressure air 8 for driving the valve from the open air port 7.

Next, FIG. 1B shows a case where a part of the valve is opened, and the high-pressure air 8 for driving the valve is removed from the opening air port 7, so that the force of the return spring 2 causes a small-diameter valve. 1 opens and a small flow 9 of gas occurs from IN to OUT of the casing 4.

Finally, FIG. 6 (c) shows a fully opened state in addition to the state of FIG. 7 (b).
From closing airport 6 to opening airport 5
The large-diameter valve 3 is opened by switching to, and a large amount of gas flow 10 is generated from IN to OUT of the casing 4.

[0009]

As described above, according to the present invention, by integrating the large-diameter valve and the small-diameter valve, the conventional pneumatic valve can be easily changed to the variable orifice type pneumatic valve, and the installation space can be saved. Has the effect of realization.

[Brief description of drawings]

FIG. 1 is a sectional view of an embodiment of the present invention, and FIGS. 1 (a), (b), and (c) are mechanical diagrams showing the order of operation, respectively.

FIG. 2 shows a cross-sectional view of a conventional pneumatic valve,
(A) and (b) of the same figure are mechanical diagrams showing the order of operation, respectively.

[Explanation of symbols]

 1 Small-diameter valve 2 Return spring 3 Large-diameter valve 4 Casing 5 Opening air port 6 Closing air port 7 Opening air port 8 High-pressure air for valve drive 9 Small amount of gas flow 10 Large amount of gas flow 11 Valve

Claims (1)

Claim: What is claimed is: 1. A pneumatic valve which opens and closes a gas flow by reciprocating the valve by switching high pressure air in a casing, wherein a valve having a diameter smaller than that of the valve is built into one end of the valve. The small-diameter valve is operated by high-pressure air independently of the valve, and the small-diameter valve is opened to control the flow rate during the closing operation of the valve.