Patent ID: 7571928
Filing Date: 2009-08-11
Classification: B60R,Y10T

Abstract:
1. A method of manufacturing an airbag cover for covering an airbag, comprising: preparing the airbag cover, forming a groove in the airbag cover with an ultrasonic machining device along one direction to form a tear line so that a thickness of a groove formed portion of the cover is varied in a thickness direction and the groove is inclined relative to the thickness direction according to a location of the groove in the airbag cover, and machining said groove to have one plane inclined surface inclined along the one direction and extending outwardly from a bottom of the groove, and another plane inclined surface inclined along the one direction to face said one plane inclined surface with a space therebetween and extending outwardly from the bottom of the groove, said one and another plane inclined surfaces being arranged asymmetrically to have different angles relative to the bottom of the groove and formed successively along the tear line.