| 摘要 |
PURPOSE: To improve the serviceability and the durability in a predetermined low temperature area and to uniformly expand or contract a shape memory alloy coiled spring by using ternary alloy having no interphase as the shape memory alloy coiled spring for closing the switching plate of a damper unit for controlling the flow of cold air. CONSTITUTION: In a refrigerator, cold air cooled by a cooler is controlled to be introduced by a damper unit 25, and introduced into a storage chamber by a cold air duct 24. In the damper unit 25, the switching plate 43 of an opening 41 is rtoatably pivoted to a case 42 communicating with the duct 24 via the opening 41, energized in an opening direction by a bias spring 44, and closed by a shape memory alloy coiled spring 46. In this case, the spring 46 is formed of ternary alloy having no interphase. The spring 46 is formed of an effective winding part which is expanded or contracted, and an invalid winding part which is not expanded or not contracted, and the original shapes recovered from the invalid part may be differentiated at the central part and both end parts. |
