| 摘要 |
PROBLEM TO BE SOLVED: To provide a method for manufacturing an air bag cover body, capable of performing the groove machining of the position, the depth of a tear line groove by a simple control even when the dimensions of moldings are dispersed. SOLUTION: In the method for manufacturing an air bag cover body using a thermoplastic resin material provided with a tear line groove on its back side by injection-molding at least the back side, when injection molding is performed, groove processing base lines 122a are formed along a portion at which a tear line groove 114 is formed, by top lines of corner stripe parts 122 which can be detected by ultrasonic detecting devices 120 attached to a laser beam machining device 118. The tear line groove 114 is formed by guiding the ultrasonic detecting devices 120 or moldings (workpiece) 112 by means of the groove machining baselines 122a. |
