VEHICLE SIDE AIR-BAG DEVICE

Body parts from the shoulder to the waist of a seated occupant are appropriately restrained by restraining forces corresponding to the load tolerances of the body parts. In a side airbag (20) of a side airbag device (10), a rear bag portion (26) in which an inflator (22) is provided is inflated and deployed earlier than a front bag portion (24) such that the internal pressure in the rear bag portion (26) is higher than that in the front bag portion (24). Thus, while a shoulder (S) and the rear portions of a chest (C) and an abdomen (B), which have a relatively high load tolerance, are restrained by the rear bag portion (26) early, the front portions of the chest (C) and the abdomen (B), which have a relatively low load tolerance, are softly restrained by the front bag portion (24). In addition, a waist (L) having a load tolerance higher than that of the shoulder (S), the chest (C), and the abdomen (B) of the seated occupant (P) is restrained by a lower bag portion (28). When the internal pressure in the lower bag portion (28) is increased, a flow of gas from the lower bag portion (28) to the rear bag portion (26) is restricted by a check valve (61). As a result, the internal pressure in the lower bag portion (28) is maintained high from the initial stage of restraint to the late stage of the restraint.