| 摘要 |
PURPOSE:To ensure a minimum flow quantity through a single valve body, by forming a notched space in at least either the valve body or valve seat neighboring to the closed position of a proportional control valve body. CONSTITUTION:A proportional valve 15 comprises the first disc-shaped part 15a, shutting off an outlet passage 26 from a communication passage 20 under a condition contacted to a valve seat 25, the second semi-spherical part 15b, for linearly changing a flow of gas passing through a passage between said part and the valve seat 25 in proportion to a moving distance of the valve 15, and an annular groove 15c, formed to the peripheral surface of the second part 15b in a position neighboring to the first part 15a. Width of said groove 15c is selected to a value smaller than height axially of the valve seat 25. Accordingly, clearance between the proportional valve 15 and an internal surface of the valve seat 25 is increased in a part of the groove 15c. |
