| 摘要 |
PROBLEM TO BE SOLVED: To reduce dust generated from an O ring when a vacuum valve is opened/closed. SOLUTION: This vacuum treatment device has a first vacuum chamber 1, a second vacuum chamber 2 and a vacuum valve for opening/closing the opening part 4 of a partition wall 3 between both chambers 1 and 2, and the valve body 6 of the vacuum valve presses the wall 3 from the chamber 2 side through the O ring 5 in a closed state of the vacuum valve. This device has also a pressure difference detecting means 8 for detecting the pressure difference between chambers, a valve body driving means 7 for driving the body 6 and a valve body driving power controlling means 9 for adjusting the valve body driving power of the means 7 according to the detected pressure difference. When the vacuum valve is closed with both chambers being evacuated, the body 6 is driven by the power that makes the deformation of the O ring smaller. When the vacuum of the chamber 1 is broken while the chamber 2 is still evacuated, the pressure difference (the increasing internal pressure of the chamber 1) is detected and the driving power of the body 6 is drastically increased so that the O ring is deformed enough to keep an airtight state.
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