Airbag device for front passenger seat

An airbag device for a front passenger seat, comprising:

• an airbag that is accommodated in a folded state in an accommodation section in front of the front passenger seat, wherein
• the airbag is configured such that a front end side thereof is attached to the accommodation section upon completion of inflation of the airbag, and that a rear surface side thereof serves as a passenger protection portion upon completion of inflation of the airbag,
• the passenger protection portion has a frontal collision restraint surface that is configured to protect a head of a passenger that moves forward in an event of a frontal collision of a vehicle, and an oblique collision restraint surface that is configured to protect the head of the passenger that moves diagonally forward in an event of an oblique collision or an offset collision of the vehicle and that is configured to protrude further backward than the frontal collision restraint surface on at least one of a right side and a left side of the frontal collision restraint surface,
• the airbag has at least two longitudinal tethers that couple the front end side of the airbag and the frontal collision restraint surface to each other, inside the airbag,
• the at least two longitudinal tethers are arranged deviated in a lateral direction from a center of the frontal collision restraint surface in the lateral direction to an oblique collision-side region on the oblique collision restraint surface side,
• the frontal collision restraint surface has at least two protruding surfaces that are configured to protrude backward upon completion of inflation of the airbag,
• the at least two protruding surfaces are arranged in alignment in the lateral direction,
• the airbag has a restraint recess portion that is configured to be recessed forward between the frontal collision restraint surface and the oblique collision restraint surface,
• an end-side protruding surface that is arranged on the oblique collision restraint surface side is configured to be located in front of an adjacent protruding surface that is arranged adjacent to the end-side protruding surface at a center side thereof in the lateral direction, upon completion of inflation of the airbag, as to the at least two protruding surfaces, and
• the restraint recess portion is inclined with respect to a longitudinal direction of the vehicle, such that a tip of the recess of the restraint recess portion is located outside a rear end of the recess with respect to an attachment centerline, upon completion of inflation of the airbag.