| 摘要 |
PURPOSE:To enable to realize the simple and sure actuation for stopping the gas outflowing from a nozzle by a method wherein a nozzle push plate is pushed in order to push down a nozzle by means of the action of a shape memory effect member due to abnormal overheating. CONSTITUTION:A heat transfer member 2 is heated by combustion and consequently a shape memory effect member 7 is also heated to some extent and generates the restoring force, which is however not enough large as to disengage the pawl 10 of a nozzle push plate 9 from a holding body 4 under the normal temperature, resulting in remaining the nozzle push plate 9 as it is. But, when the temperature of the heat transfer member 2 rises abnormally high, the temperature of a heat sensitive plate 6 also rises abnormally high and causes the shape memory effect member 7 to generate the larger restoring force than that under the normal temperature in order to try to restore the original shape of the member 7 so that the pawl 10 of the nozzle push plate 9 is disengaged from the holding body 4 and consequently the nozzle push plate 9 is shifted toward a nozzle 8 in order to shift the nozzle 8 downward by pushing down a flange 15 formed on the nozzle 8. At this time, a porous substance 12 and a gap controlling packing 15 are brought into a close contact with each other, resulting in stopping the jetting of gas. |
