| 摘要 |
<p>PROBLEM TO BE SOLVED: To enable efficient forming of a linear groove having a reproducible predetermined breakage resistance with a predetermined thickness retained at a skin surface side by a small power consumption under a simple control while avoiding a damage of a design surface. SOLUTION: An apparatus for forming the linear groove on an air bag of a skin for an automobile comprises a heater 8 and an ultrasonic machining unit 4 aligned in parallel at a rear surface 3b side of the skin 3 made of a resin fixedly held, so that a front surface 3a is closely contacted with a flat surface 1a. An oscillation horn 4C of the unit 4 is regulated at its position so that a clearance between its distal end and the surface 1a coincides with the set residual thickness of the surface 3a side. The heater 8 and the unit 4 are moved along a line to be machined to preheat the machining part, softened and sequentially melted at the resin for the skin by ultraviolet oscillation immediately after the softening, the molten resin is removed to its side, and the groove 6 is formed.</p> |
