AIR BAG DEVICE

PROBLEM TO BE SOLVED: To suitably spread a bag with a simple structure. SOLUTION: A trapezoid hood part 5c having a side in a diffuser 2b side shortened and an opposite side lengthened is formed as one body on a flap 5 having an inflator 2 fitted on a bottom part of a case 1 in a housed condition and a folded bag 3 stored in a top part of the case and including a cover part 5a preventing spontaneous spread of the bag. The hood part covers the bag in an initial spread condition and breaks after that to spread the bag eventually. Since an inflation shape of the bag in the initial spread condition can be freely established by the hood part even if a gas jet outlet is provided at a biased position to the bag, inflation amount of the bag in the gas jet outlet side where gas inflow pressure to the bag is intensified is reduced. A final spread shape of the bag after breakage of the hood part can be made, for example large at a center part, and equal in left and right by increasing inflation amount in a side of lower inflow pressure. COPYRIGHT: (C)2004,JPO