Side airbag device

A side impact airbag device for installation in a seat back of a vehicle seat and adapted to deploy in response to an output signal from a sensor in the event of a side impact comprising:

• an airbag;
• an inflator provided in the airbag so as to supply an inflation gas to the airbag in a folded state, thereby deploying the airbag to a deployed state;
• and
• an inner tube formed of a fabric and having an end provided to cover discharge holes of the inflator in order to change a direction of a flow of the gas discharged from the inflator, wherein
• a first end of the inner tube is closed and protrudes toward a center of the airbag in the deployed state, and upper and lower ends defining second ends are open and separated in a vehicle height direction of the airbag in the deployed state,
• the inner tube is folded back at a folded-back portion inside the airbag when the airbag is in the folded state, and is unfolded when the airbag is in the deployed state,
• the inner tube is folded back together with a portion of two base fabrics of the airbag such that the portion of one of the two base fabrics is positioned between the folded-back portion and an unfolded portion of the inner tube in the folded state,
• the airbag includes two different portions defining a protruding portion, in which the inflator is disposed, and a body portion, in which the folded-back portion and the second ends of the inner tube are positioned,
• the first end and the second ends of the inner tube extend into the body portion beyond a front-most surface line of the seat back in a vehicle length direction, and
• only the inner tube in the body portion adjacent to the protruding portion of the airbag faces the inflator when the airbag is folded.