| 摘要 |
PROBLEM TO BE SOLVED: To reduce hysteresis of an output pressure in a solenoid valve comprising a hollow sleeve, on which an input port, an output port and an exhaust port are formed, a spool, which is a shaft-like member inserted inside the sleeve and which communicates and blocks the respective ports, and a solenoid part having a movable member for moving the spool in an axial direction. SOLUTION: A spool is constituted by an outer spool 60 opening and closing ports 52, 54, 56 of a sleeve 50, and an inner spool 70 contacting a shaft 38 of a solenoid part 30 and opening and closing a feedback chamber 58. A spring 80 is designed to an extent required for just receiving a sum of a load applied to the outer spool 60 by a feedback force generated when an output pressure is a predetermined pressure P1 and a load applied to the outer spool 60 by an energizing force of a spring 44, and is interposed between the outer spool 60 and the inner spool 70. Thereby, by pressurizing the inner spool 70 by the solenoid part 30, the outer spool 60 is moved in the axial direction via the spring 80, so as to open and close each of the ports 52, 54, 56. Also, the feedback chamber 58 under a closed condition can be opened by the energizing force of the spring 80. COPYRIGHT: (C)2010,JPO&INPIT
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