JPH02185681A - Vacuum exhausting device - Google Patents

Abstract

PURPOSE:To prevent counterflow between vacuum exhaust chambers even though both solenoid valves for exhaustion are opened, by furnishing the exhaust part of each vacuum exhaust chamber with a counterflow preventive valve. CONSTITUTION:The degree of vacuum in a vacuum exhaust chamber 2 gets considerably higher during exhaustion, i.e., with a vacuum pump 7 in operation, and while a solenoid valve 4 for exhaustion is open, and meantime solenoid valves 3, 5, 6 are closed. Even though the solenoid valve 3 for exhaustion is opened in order to exhaust another vacuum exhaust chamber 1, the gas will not make counterflow from the one exhaust chamber 1 to the other 2 owing to the action of a counterflow preventive valve 9. Also exhaustion in the opposite sequence does not either causes counterflow of the gas from the one chamber 2 to the other 1 through the action of another counterflow preventive valve 8.

Description

[Detailed Description of the Invention] [Field of Application of W Tojo] This invention relates to a vacuum evacuation device for a closed space.

[Conventional technology]

FIG. 2 is a piping diagram of a conventional evacuation device that evacuates two evacuation chambers using one vacuum pump.

In the figure, (1) and (2) are vacuum exhaust chambers, (3)
・(4) is an exhaust solenoid valve to connect the vacuum pump to the vacuum exhaust chamber, (6), (6) is the vacuum exhaust chamber 11)
, (7) rounded solenoid valves that return each
) is a vacuum pump.

Next, the operation will be explained. Vacuum evacuation chamber (υWhen fully evacuating, first operate the vacuum pump (7), then [16
Open valve (3). After the evacuation chamber (1) reaches a certain degree of vacuum, the solenoid valve (3) is closed. This completes the evacuation of the evacuation chamber (1).Next, the evacuation of the evacuation chamber (2) opens the solenoid valve (4), and after reaching a certain degree of vacuum, closes the solenoid valve (4). Make it. Below are the solenoid valves (3) I (4)
The vacuum chamber is evacuated by controlling the opening and closing of the vacuum chamber.

Also, the ninth solenoid valve (5) is used to return the vacuum chamber to atmospheric pressure.
6) Open or put N2 etc.

[Problem to be solved by the invention]

The exhaust system of conventional vacuum exhaust equipment was configured as described above, so when one vacuum exhaust chamber is being evacuated and has reached a considerable degree of vacuum, the exhaust solenoid valve of the other vacuum exhaust chamber must be opened. Then, the vacuum exhaust chamber is made conductive by the exhaust electromagnetic valve, and the gas flows back toward the lower pressure side. For this reason, when one vacuum exhaust chamber is being evacuated, the other exhaust solenoid valve cannot be opened or closed.
Therefore, the exhaust l! There was a problem in that the control of opening and closing the solenoid valve was complicated and difficult to operate.

This invention has been made to solve the above-mentioned problems, and an object of the present invention is to provide an evacuation device in which backflow between evacuation chambers does not occur even when both evacuation solenoid valves are opened.

[Means to solve the problem]

The evacuation device according to the present invention has a check valve attached to the exhaust section of the evacuation chamber.

[For production]

In the vacuum evacuation device of the present invention, backflow of gas is prevented by providing a check valve in the exhaust section of each evacuation chamber, thereby making it possible to operate the vacuum evacuation solenoid valve.

〔Example〕

An embodiment of the present invention will be described below with reference to the drawings. 1st
The figure is a piping diagram of a vacuum evacuation system showing an embodiment of the present invention, which includes a backflow prevention valve (8) in the conventional system.

(9) is attached, and the other symbols are the same as those of the conventional type.

Next, the operation will be explained. The vacuum evacuation chamber (2) is under evacuation. That is, it is assumed that the vacuum pump (7) is in operation, the exhaust valve (4) is open, and the degree of vacuum is quite high. Also, solenoid valve (3), +5)
, (6) is closed. Next, the exhaust electromagnetic valve (3) is opened to exhaust the vacuum exhaust chamber (1). Due to the action of the check valve (9), the vacuum evacuation chamber (+1) is removed from the evacuation chamber (2).
) There is no possibility of gas flowing backwards. Furthermore, even if the gas is evacuated in the reverse order to the above, the backflow prevention valve (8) prevents the gas from flowing back from the evacuation chamber (2) to the evacuation chamber +1).

〔Effect of the invention〕

As described above, according to the present invention, a backflow prevention valve is attached to each evacuation chamber, so there is no backflow of gas during evacuation, and the evacuation solenoid valve can be freely operated. This has the effect of making it easier to control vacuum evacuation.

[Brief explanation of the drawing]

FIG. 1 is a piping diagram between evacuation chambers according to an embodiment of the present invention, and FIG. 2 is a piping diagram of a conventional evacuation device. In the figure, (υ, (21 is the evacuation chamber, (3) to (6
) #-1 solenoid valve, (7) is a vacuum pump, (8),
(9) indicates a check valve. In addition, the same symbols in the figures indicate the same or equivalent parts.

Claims (1)

[Claims] A vacuum evacuation device characterized by being equipped with a check valve so that two evacuation chambers can be independently evacuated by one vacuum pump.