Patent ID: 7607681

Claim:
An airbag cover comprising: a single-layered cover material formed from a synthetic resin material by molding having a lid portion which is opened to form a projection opening through which an airbag projects and a thin breakable portion defines the lid portion to be broken by a pressure of the inflating airbag, and formed, a part of the breakable portion which lies on a distal edge of the lid portion which lies away from a hinge portion of the lid portion when the lid portion is opened and where the breakable portion is provided being formed into a distal edge straight section which is provided in the shape of a straight line, the distal edge straight section being formed through cutting operation in which a working tool is moved over a rear surface of the cover material after the cover material has been molded so as to form a notch therein by a cutting blade of the working tool, wherein the distal edge straight section is formed by providing discontinuously a thick portion whose thickness is made to fall in the range of 1.0 to 1.6 mm and a thin portion whose thickness is made to fall in the range of 0.6 to 1.0 mm so as to be thinner than the thick portion within a working area whose thickness is set to range from 2.0 to 3.0 mm, and wherein, in a sectional area change curve marked by plotting distal edge section values of sectional areas taken in 50 mm segments along the distal edge straight section, the thick portion and the thin portion are formed so that a maximum change rate, which is a rate of difference between a maximum of the distal edge section values and a minimum of the distal edge section values based on the maximum, is made to be 15% or more, without providing an area where the distal edge section values of the sectional areas decrease from a center of the sectional area change curve towards both ends thereof, as a range where the distal edge section values of the sectional areas are larger than the minimum distal edge section value.