Patent ID: 7481456

Claim:
An airbag apparatus comprising: an airbag having at least a pair of base fabric pieces, at least one of which having a center part from which high-pressure gas is introduced into an internal space enclosed by the pair of the base fabric pieces, thereby expanding the airbag; a vent hole which discharges internal gas of the airbag; a plurality of rupture joining parts each having a starting-end and a finishing-end, the finishing-end provided at an outer position of the airbag than the starting-end, the plurality of rupture joining parts joining the base fabric pieces in a manner breakable by the high-pressure gas expansion; and a vent hole cover having a connecting part at which the vent hole cover is connected to the airbag by the rupture joining parts, wherein: the airbag has an outer expansion part provided at a position outside the finishing-ends of the rupture joining parts; the plurality of rupture joining parts are rotationally symmetric to each other about the center of the base fabric pieces, and partially overlap each other in the circumferential direction; and the connecting part of the vent hole cover is provided in the vicinity of a middle position of the two finishing-ends of an adjacent pair of the rupture joining parts.