| 摘要 |
PURPOSE:To enable a valve to be stably opened and closed, by controlling the valve by a number of pulses a little smaller than the number of pulse signals required for moving a valve unit from the full closing position, where it is seated on a valve seat, to the full opening position, as the control method of full opening position of the electric motor driven expansion valve. CONSTITUTION:A valve seat 4 is provided in a valve main unit 1 so as to cause a curved part 3 to communicate with flow paths 2, and a driver 8 moving a valve unit 6 is driven by a pulse motor 9. As the control method of full opening position, a number of pulses at a full opening instruction input to the pulse motor 9 are decreased to a number of pulses (X0-beta, alpha<beta) a little smaller than a number of pulses (X0-alpha) required for moving the valve unit 6 from its full closing position to its actual full opening position, controlling a valve by the number of pulses (X0-beta, alpha<beta). In this way, stable control of opening the valve can be performed by preventing a stopper 11 of the driver 8 from being adapted to a base 12 and also preventing an abnormal noise from being generated due to a locked condition. |
