| 摘要 |
A direct-acting electric operated valve has a stem which reciprocates by an electric motor without using air pressure. In this direct-acting electric operated valve, as the stem 2 vertically reciprocates, a first passage 11 and a second passage 12 are switched over. A cam mechanism 4 is formed for converting rotary reciprocating motion of an eccentric cam 42 which rotary reciprocates by an electric motor 40 into vertical reciprocating motion. The eccentric cam is retained at an upper retaining position X which is slightly exceeding a top dead center X 1 and at a lower retaining position Y which is slightly exceeding a bottom dead center Y 1 . In a state in which an integral coil spring 35 which is previously held between an upper spring seat 32 and a lower spring seat 34 in its compressed state is mounted to a spring shaft 30 which extends from a cam mechanism, the coil spring 35 is accommodated in a spring case 36 connected to the stem.
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