Patent ID: 8029016

Claim:
A knee-protecting airbag device comprising: an airbag with a base end attached to and accommodated in a vehicle body in front of an occupant; and an inflator that supplies gas to the airbag from a gas discharge port, the knee-protecting airbag device inflating and deploying the airbag from the base end to a position between the vehicle body and knees of the occupant with the gas from the inflator, wherein the knee-protecting airbag device comprises: a diffuser accommodating the inflator and disposed in the airbag, the diffuser having an opening that allows the gas from the inflator to flow in the airbag; and at least one tether disposed in the airbag so as to face the opening of the diffuser, the tether defining the inside of the airbag in a deploying direction, wherein the opening of the diffuser is closed before the inflator is activated and is opened by the gas from the inflator when the airbag deploys, and wherein, during activation, the gas that is supplied by the inflator is maintained in an accommodating portion of the diffuser while the opening is closed and the entirety of the closed opening is substantially simultaneously opened at a predetermined pressure.