| 摘要 |
PURPOSE:To obtain a simple structure gas shut-off valve which may cut-off the supply of gas, immediately after abnormality such as, for example, gas leakage occurs, by providing a three-way valve which may be swung around a support shaft in association with an external signal, integrally with a valve body which is parted into two upper and lower chambers by a diaphragm. CONSTITUTION:When gas leakage occurs so that an external signal source 22 such as, for example, a gas alarm applies current inverse to the normal current direction to a solenoid coil 21 in three-way solenoid valve A2, magnetic poles 20a, 20b in an electromagnet 20 are magnetized with S, N poles, respectively. Thereby, a pair of permanent magnets 23a, 23b take attraction and repulsion, respectively with respect to the magnetic poles 20a, 20b, which magnets 23a, 23b are set in the top surface of the diaphragm 17 that may moves in a seesaw-like manner around a support shaft 6. As a result, passages 25, 27 are opened and closed, respectively. Therefore, gas is charged into an upper chamber 6 through the passages 25, 27 so that the diaphragm 5 is passed down by means of a spring 8, thereby a gas inlet nozzle 11 is closed by a main valve 10. |
