抄録
The ISO and JIS standards concerned with a method of measurement of effective area are frequently used to determine the flow rate characteristics of a solenoid valve. In the ISO standard (ISO 6358, 1989), the relationship between the effective area and the pressure ratio is obtained by both the flow rate through a valve and the pressure ratio across the valve. On the other hand, in the JIS standard the compressed air is discharged from the tank to the atmosphere after the solenoid valve is opened, and the effective area of a valve in which flow is choking is determined by the initial pressure in a tank with a constant volume, the remaining pressure and the discharge time.
In this paper, a new measuring method of the effective area of the solenoid valve, named the charging method, is proposed. The effective area is obtained by charging the atmospheric air into the evacuated tank through the solenoid valve. This method is useful for various pressure ratios i.e. that from sonic flow to subsonic flow, and is adequate to prepare a smaller testing set than that of the ISO method. In addition the noise generated during the measurement is reduced markedly.
