INFLATER AND AIR BAG DEVICE

PROBLEM TO BE SOLVED: To provide an inflater capable of certainly detecting leakage of gas even if a partition wall is not provided in a pressure-resistance vessel and an air bag device provided with the inflater. SOLUTION: When gas pressure in the pressure-resistance vessel 10 of the inflater 1 is sufficiently high, a main piston 94 and a sub-piston 102 are positioned at positions shown in Figure and a stationary electrode 120 and a movable electrode 114 are apart from each other. When leakage of gas from the pressure-resistance vessel 10 occurs, length in a longitudinal direction (cylinder axial direction) of the pressure-resistance vessel 10 is slightly shortened. The main piston 94 fixed to a rear end of the pressure-resistance vessel 10 by a connection member 96 is displaced accompanying with shortening of the pressure-resistance vessel 10 and the sub-piston 102 is also displaced accompanying with this. A shaft body 110 and the movable electrode 114 integrated with it are pressed by a spring 118 and displaced accompanying with displacement of the sub-piston 102 and the movable electrode 114 is brought into contact with the stationary electrode 120. Thereby, a warning device 130 performs, for example, warning action such as lighting or flashing of a warning lamp. COPYRIGHT: (C)2005,JPO&NCIPI