| 摘要 |
PROBLEM TO BE SOLVED: To solve the problem that a depressed part, which downwardly and gradually decreases in diameter, is formed in a bottom part of a water tank to be a drain port part, a drain port metal fitting is disposed in the drain port part having difficulty in obtaining accuracy, and stain of the boundary between the drain port part and the drain port metal fitting is covered with a drain plug to improve appearance, but in the view-point of water cut-off an elaborate drain port part has to be formed together with the drain port metal fitting in the water tank, and in this case it is difficult to form such an elaborate drain port part together with the drain port metal fitting, particularly if the drain port part is made of ceramic.SOLUTION: A drain plug device is opened/closed by vertical movements of a drain plug. The drain plug is constituted in such a manner that a depressed part is formed in a bottom part of a water tank; an inward flange formed in the depressed part is held by and attached to a drain port fitting and a connecting pipe in a drain port part; a cover substantially flush with the bottom surface of the water tank and vertically movable inside the depressed part is provided on the drain port part; and then a shaft part inserting and holding a packing sealable with the drain port fitting is provided on the lower surface of the cover. |
