VACUUM PRESSURE CONTROL SYSTEM AND CONTROLLER FOR VACUUM PRESSURE CONTROL

摘要

PROBLEM TO BE SOLVED: To provide a vacuum pressure control system and a controller for vacuum pressure control which are compact, inexpensive and excellent in control responsiveness.SOLUTION: A vacuum pressure control system 1 collects performance characteristic data of a vacuum valve 2 at first to fourth inflection points B1-B4 where a change rate, of operation pressure of the vacuum valve 2 measured by an operation pressure sensor 3k, changes. A controller 4 generates a valve open degree control signal using the performance characteristic data and outputs the signal to an electropneumatic regulator 3. The electropneumatic regulator 3 regulates operation pressure of the vacuum valve 2 based on a valve open degree measurement signal of the operation pressure sensor 3k and the valve open degree control signal of the controller 4. Thus, the vacuum pressure control system 1 causes internal pressure of a vacuum vessel 8 to reach a vacuum pressure target value by opening/closing the vacuum valve 2 according to an instruction of the controller 4 so as to control a flow rate of a gas flowing from the vacuum vessel 8 to a vacuum pump 9.SELECTED DRAWING: Figure 9