SIDE AIRBAG DEVICE, VEHICLE SEAT PROVIDED WITH SAME, AND METHOD FOR MANUFACTURING SIDE AIRBAG DEVICE

This invention relates to a side airbag device stored inside a vehicle seat and fixed to a side frame. The device includes an airbag that expands and deploys to restrict an occupant; an inflator that supplies expansion gas to the airbag; and a bracket connected to the side frame that holds the airbag and the inflator. The airbag includes a prepush chamber having an inflator stored therein and mainly deploys inside of the side frame; and a main chamber connected to the prepush chamber and mainly deploys forward of the side frame. The bracket includes a first surface oriented in the forward direction of the vehicle; and a second surface oriented to the inside of the seat in the width direction of the vehicle. When the airbag is stored by being folded and/or rolled, at least the main chamber is disposed on the first surface of the bracket.