| 摘要 |
<p>PROBLEM TO BE SOLVED: To provide a voltage block device for preventing erosion of a valve seat of a four-way valve and the surface of a ball. SOLUTION: A valve has a housing 52 and a movable component 50 in the housing. A first port 66, a second port 68, and a third port 70 are formed in the housing. A first passage 116 is formed in the movable component. By the motion of the movable component in the housing, the communication of the first port with the second port through the first passage 116 and the communication of the second port with the second port through the first passage are selectively conducted. At least one port of the first port and the second port has a first member 74 coming in contact with the movable component and a second member 76 holding the first member. The second member is made of a semiconductor material. The region of a movable valve component positioning in the periphery of a first end of at least the first passage is preferable to be semiconductive.</p> |
