| 摘要 |
PROBLEM TO BE SOLVED: To prevent a drain valve from being closed early and to stabilize the discharge amount of wash water even when pressure loss at a drainage destination of the wash water is small in constitution that utilizes buoyance by a float for an opening/closing operation for the drain valve opening and closing a drain port for draining the wash water.SOLUTION: A drain valve device 40 includes: a valve member 55 which opens and closes a drain port 14; a float 50 which acts on the valve member 55; a water storage cylinder 43 which has the float 50 arranged inside; and a rotation transmission member 32 which lifts the valve member 55 through a first ball chain 35 to open the drain port 14. The valve member 55 is configured to descend associatively with the float 50 descending as the water level in the water storage cylinder 43 falls and then to close the drain port 14, and the float 50 is configured to generate a buoyancy for raising the valve member 55 to a second height position higher than a first height position where the valve member is lifted by the rotation transmission member 32 through the first ball chain 35. |
