| 摘要 |
PROBLEM TO BE SOLVED: To estimate the valve opening of a pressure control valve by performing an arithmetic operation. SOLUTION: Pressure received with a diaphragm 19 for pressure control valve from an upper side diaphragm chamber 20 can be computed from loading pressure Pa detected by a third pressure sensor 48. The pressure received with the diaphragm 19 for pressure control valve from an lower side diaphragm chamber 21 can be computed from the pressure Pa detected by a fourth pressure sensor 50. Therefore, a control circuit 18 seeks for a pressure difference received with the diaphragm 19 for pressure control valve from detection signals from the pressure sensors 48, 50 and computes a displacement of the diaphragm 19 for pressure control valves from the pressure difference and a flow coefficient of the pressure control valve 14, namely the degree of valve opening of a valve body 14c which carries out displacement integrally with the diaphragm 19 for pressure control valves. The flow rate supplied to downstream side from this degree of valve opening is guessed. COPYRIGHT: (C)2007,JPO&INPIT
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