To avoid foreign matter from being retained between an outer ring valve seat and a valve disc, and to eliminate air binding by lifting the valve disc with a small operating force of a bimetal ring.
A conical inclined part 12 is formed on an outer periphery of the outer ring valve seat 7, and an upper flat part 15 and a lower flat part 16 are formed at the upper end and the lower end of the inclined part 12, respectively, and a bimetal ring 13 having an end is arranged. An interposing ring 14 having only one part 14a formed at a predetermined width and having the other parts with a narrow width is arranged between the bimetal ring 13 and the valve disc 11. The bimetal ring 13 is contraction-closed and moves on the inclined part 12 at a low temperature, and the valve disc 11 is rocked and lifted using, as a point of action of force, the part 14a formed at the predetermined width of the interposing ring 14. The valve disc 11 is separated and opened from the inner and outer ring valve seats 6 and 7, and is mounted on the upper flat part 15.
JPH06241394A | 1994-08-30 |