Vehicle airbag system

A vehicle airbag system, comprising:

• an airbag module located inside an instrument panel, the airbag module having an airbag accommodated in a case and a gas generator which generates an airbag inflation gas, wherein
• the vehicle airbag system includes
• a front support located at a front side of the airbag module and protruding downward from the instrument panel;
• a back support located at a back side of the airbag module and protruding downward from the instrument panel;
• a back plate located on a back side of the case to reduce deformation of the case toward the back side in the event of deployment of the airbag;
• corner cover portions which are provided to the case and which cover both corner portions on a back side of the folded airbag,
• a plurality of projections which are provided to a lower end portion of a back wall of the case and which project to a back side, and
• a stud bolt whose head is housed in a depression formed by a corresponding one of the projections, and whose shank portion passes through the corresponding one of the projections to project to a back side, wherein
• the airbag is folded into a rectangular shape in plan view and is accommodated in the case,
• the case is supported on a steering member extending in a vehicle width direction inside the instrument panel, and is held on the front support,
• the back plate includes
• a stiffness portion including a plurality of beads which extend only in the vehicle width direction and which are arranged vertically to each other, and
• an impact absorber comprised of a bent portion obtained by bending part of the back plate toward the back side, the impact absorber being provided at a location lower than the stiffness portion and allowing easy deformation when an impact load is applied to the instrument panel from above, and
• a lower end portion of the back plate is supported on the back wall of the case with a nut fastened to the stud bolt, and an upper portion of the back plate is held on the back support.