Patent ID: 8424907

Claim:
An airbag apparatus comprising: an airbag that is inflated by inflow of an inflation gas to cushion an occupant; and a vehicle body structure that supports the airbag receiving the occupant, wherein the airbag includes: an outer circumferential wall that has a restraining wall receiving the occupant and a vehicle body side wall supported by the vehicle body structure when the occupant is cushioned; a vent hole that is disposed at the vehicle body side wall and opened to discharge the inflation gas when the internal pressure increases; a patch that closes the vent hole; and a protrusion that has a conical shape with the front narrowed when inflation is finished, around the interface of the restraining wall and the vehicle body side wall; wherein the vehicle body structure has a reaction force-applying support portion that supports the protrusion and applies a reaction force substantially opposite to the approach direction of the occupant to the protrusion, when the airbag cushions the occupant after the airbag finishes inflating, wherein the protrusion has a reaction force-receiving contact portion that is in contact with the reaction force-applying support portion and is partially recessed toward the occupant approaching by receiving the reaction force, wherein the vent hole and the patch are disposed at the vehicle body side wall of the protrusion around the reaction force-receiving contact portion, wherein the vent hole is disposed along the axial center of the protrusion at a position where the vent hole is not pressed, in parallel with the reaction force-receiving contact portion, at the reaction force-applying support portion when the airbag cushions the occupant, wherein the patch disconnects the edge of the reaction force-receiving contact portion to be spaced from the vehicle body side wall, and connects at least both edges opposite to the circumferential direction about the axial center of the protrusion that protrudes in a conical shape to the outer circumferential wall of the airbag while developing and connecting the patch and the circumferential edge of the vent hole to overlap each other in a flat shape, wherein the patch is positioned to keep the vent hole closed before the occupant is cushioned after the airbag finishes inflating, and wherein the patch is disposed at a position where the region from the portion covering at least the vent hole to the edge of the reaction force-receiving contact portion is not pressed against the reaction force-applying support portion when the airbag cushions the occupant, and is spaced from the circumferential edge of the vent hole that moves as the reaction force-receiving contact portion is recessed when the occupant is cushioned.