EXHAUST RATE CONTROL METHOD BY ELECTRIC VACUUM VALVE, EXHAUST RATE CONTROL SYSTEM BY ELECTRIC VACUUM VALVE, METHOD FOR DETERMINING VALVE OPENING DEGREE SETTING POINT OF ELECTRIC VACUUM VALVE USED FOR EXHAUST RATE CONTROL, AND RECORDING MEDIUM

摘要

Provides a method for controlling the exhaust speed due to the electric vacuum valves to approach the pressure in the chamber to the target pressure chamber estuaries times to set the set point for switching the valve opening degree of the electric vacuum valve to a simple and inexpensive. Controlling the valve opening degree of the electric vacuum valve 21 in stages according to the geometric drainage, and each valve opening, the vacuum pump is exhausted from the viscous flow region (13), a pressure sensor 15 measures the vacuum pressure in the chamber room between the pressure drop curve and then measured the (Y1, Y2, Y3, Y4), the pressure drop curve (Y1, Y2, Y3, Y4) for temporally delaying in order to approximate to the target pressure estuaries times (X), the pressure drop curve determining the intersection point with the electric vacuum valve 21, the set point (P11, P12, P13), for switching the valve opening and, based on that after the set point (P11, P12, P13), the valve opening degree of the electric vacuum valve 21 the conversion to, and controls the exhaust rate of the viscous flow region. ;