| 摘要 |
PROBLEM TO BE SOLVED: To solve the following problems: a valve body cannot be opened because the valve body is pressed against a valve seat by high water pressure, when the high water pressure acts in the valve opening direction of an electromagnetic valve by a water hammer etc., in the case where the two electromagnetic valves 3 and 4 are serially provided for the prevention of the occurrence of poor water sealing; and a block 2 may be broken because water accumulated in an intermediate water supply passage 22 is expanded when being finally frozen, after the block 2 is cooled from a surface of the block 2 at a low temperature of outside air in winter etc., in the case of the water is kept in the state of being accumulated in the intermediate water supply passage 22 for connecting both the electromagnetic valves 3 and 4 together. SOLUTION: First and second relief valves 6 and 7 are connected to both the electromagnetic valves 3 and 4 in parallel, respectively; a branch passage 71 for connecting the second relief valve 7 to the intermediate water supply passage 22 is connected to an approximately central portion of the intermediate water supply passage 22; and finally, the water pressure is released to a downstream water supply passage 23 from a portion to be frozen. COPYRIGHT: (C)2008,JPO&INPIT
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