PURPOSE: To restrict leakage of high pressure fluid at a neutral time to decrease an ineffective flow rate directly discharged to a low pressure side by communicating a high pressure supply line with a discharge line via a metering port of which an opening area is changed according to a movement quantity of a spool.
CONSTITUTION: In the case where an operation signal is not inputted to a linear motor 20, namely, at a neutral time, in consideration of metering characteristics of respective metering ports 56a, 56b opened to a valve body 70, opening areas thereof are made zero so as to make fluid leakage zero. On the other side, in the case where the operation signal is inputted to the linear motor 20, a spool 49 is operated together with an operation shaft 2 via a movable member 3. In accordance with a movement quantity of the spool 49, opening areas of the respective metering ports 56a, 56b are adjusted and a flow rate in compliance with the opening areas is discharged from a discharge line 52. Accordingly, a flow of high pressure fluid in respective high pressure supply lines 46a, 46b continuous to respective control lines 47a, 47b is generated.
TAMURA HIROHISA
KOGARASHI SHIGEHARU
TOKYO SEIMITSU SOKUKI KK