Continuing in the approximately upper direction of the drum section conservation

摘要

PROBLEM TO BE SOLVED: To improve development stability of a head part protection part especially by rolling up a side air bag, which is provided with a body part protection part and the head part protection part, toward a gas blowout port side of an inflator so that its face on the opposite side to the seat center is arranged on the inside and housing the side air bag in the rolled up condition inside an air bag unit. SOLUTION: Inside a seat bag 3, an air bag unit 21 is arranged on the pad 15 back side of a side support part 3a on the left side with its longitudinal direction matched with the vertical direction substantially. The air bag unit 21 possesses a reaction can 22 with a U-shaped cross section, and a side air bag 24 is housed on the opening side in the reaction can 22, while on the depth side of the reaction can 22, an inflator 23 including an ignition unit and an explosive is housed. The air bag 24 is provided with a body part protection part 24a to be developed from the body part to the head part of an occupant and a head part protection part 24b to be applied to the head part of the occupant, and the body part protection part 24a is arranged so as to be extended in the forward and backward directions at the substantially same height as the inflator 23 in development of the air bag 24.