| 摘要 |
PURPOSE:To reduce the operating force by equalizing mutually the area of pressure receiving surface of a valve body and that of a piston so that the pressure oil cannot be acted on a movable part. CONSTITUTION:When a coil 1 is not magnetized, a movable part 20 is pressed by a spring 23 in the right direction to cut off the communication between a port P and a part C. When the coil 1 is magnetized, a movable iron core 2 is atrracted to hit a piston 21, and the movable part 20 is driven in the left direction against the spring 23. Consequently, the communication between the port C and a prot T is cut off and the communication between the port P and the port C is formed. In this case, since the diameter d2 of the cylinder 24 of a valve body 22 is made to be equal to the diameter d1 on the contacting part of the projected part 24a of the cylinder 24, in such a condition that the movable part is moved in the left direction due to the magnetization of the coil 1, the forces acting on the valve body 22 and the piston 21 counterbalance each other, and the force due to pressure oil is not applied on the movable part 20. Thus, the operating force can be reduced.
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