| 摘要 |
PURPOSE:To eliminate the application of water pressure in the direction to open a valve and consequently prevent a valve body from being opened wider than necessary due to water pressure rise by a method wherein a configuration memory alloy is rendered to drive itself so as to pivot a valve body. CONSTITUTION:During the time when cooling water temperature is low, the configuration memory alloy 30 twists itself in the direction to roll its coils in, resulting in shutting-off a second circulating water passage 15 by a valve body 20. With the gradual water temperature rise, the configuration memory alloy 30 starts to untwist itself in the direction to roll its coils up, resulting in pivoting the valve body 20 to open the second circulating water passage 15. Because the valve body 20 is of pivotable type as mentioned above and consequently the water pressure caused by the cooling water inflowing from a circulating water passage 5 or a by-pass water passage 7 does not apply in the direction to allow the valve body 20 to open the valve, no trouble of the opening of the valve body 20 due to water pressure rise occurs even if, for example, the rotational speed of an engine 1 becomes high. |
