Airbag device

An airbag device comprising:

• an airbag which inflates from a state of a folded body by receiving an inflation gas;
• and
• a shape maintaining member having flexibility which covers the folded body to maintain a folded shape of the folded body and to resist a spring back force following folding that forms the folded body, wherein:
• the folded body has a three-dimensional shape including a bottom surface portion, a ceiling portion disposed to face the bottom surface portion, and a side surface portion between the bottom surface portion and the ceiling portion;
• a fastener for locking an end portion of the shape maintaining member protrudes from a vicinity of an outer peripheral edge of the bottom surface portion;
• the shape maintaining member is formed of a flexible sheet material including a ceiling cover portion which covers the ceiling portion of the folded body, a side surface cover portion which extends from an end portion of the ceiling cover portion and covers the side surface portion, and a bottom surface cover portion which extends from the side surface cover portion to cover the bottom surface portion and has a locking hole to be locked to the fastener;
• the ceiling cover portion is provided with a center portion covering a vicinity of a center of the ceiling portion and constituted to linearly extend from the center portion to both sides of the ceiling portion so as to traverse the ceiling portion and one end side of both sides of the ceiling cover portion is fixed as a terminal to an edge side of the ceiling portion and the other end side is connected to the side surface cover portion;
• and
• the shape maintaining member in a state of being flatly spread is configured to linearly arrange the bottom surface cover portion and the side surface cover portion which extend from the locking hole to a fixed portion of the ceiling cover portion which is the portion fixed to the edge side of the ceiling portion and the ceiling cover portion.

A folding method of an airbag which inflates from a folded state by receiving a gas, the airbag including:

• an vehicle-body-side wall portion provided with an inflow opening to inflow the gas;
• and a driver-side wall portion which is arranged so as to oppose the vehicle-body-side wall portion in a state where an outer peripheral edge of the driver-side wall portion is continuous with an outer peripheral edge of the vehicle-body-side wall portion, the folding method comprising:
• providing a bag folding machine including:
• a bottom-side base plate;
• and a ceiling-side base plate disposed oppositely to the bottom-side base plate, the ceiling-side base plate including a projection portion being provided in a vicinity of the inflow opening and protruding to a side of the bottom-side base plate;
• spreading the airbag at a portion between the bottom-side base plate and the ceiling-side base plate so that the vehicle-body-side wall portion faces the bottom-side base plate in a state where the vehicle-body-side wall portion opposes the driver-side wall portion;
• and
• gathering an outer peripheral edge of the airbag above the inflow opening to fold the airbag so that the airbag is disposed around the projection portion and is interposed between the ceiling-side base plate and the bottom-side base plate,
• wherein:
• a width of the projection portion is reduced gradually toward the bottom-side base plate;
• when the outer peripheral edge of the airbag is gathered above the inflow opening to fold the airbag, a recess portion is formed on a surface of the airbag opposing an inflow opening side surface of the airbag;
• and
• an opening width of the recess portion is reduced gradually toward the inflow opening side surface.