| 摘要 |
PURPOSE:A united lens consisting of a plurality of lens with each optical axis offset is used to concentrate divided laser beams. Before concentration, laser beams are intersected each other to project onto inner surface of cylinder member thereby effecting a multiplace, simultaneous inner surface welding of high quality and high efficiency. CONSTITUTION:A laser beam 4 emitted from an oscillator is projected through a center portion of a joint lens 6 which is a joined assembly of eight fan-shaped lens sections of same size and same quality. The laser beam 4 is devided into 8 beams by lens sections 7 and each devided laser beam 4a is concentrated on each optical axis 8 of respective lenses. Each laser beam 4a intersects in front of each concentration, because each optical axis 8 exists outside of lens section. As laser 14a intersects, it is less likely prevented by side wall of a cylinder 8. This provides a highly densitied energy concentrated onto welding zone, whereby high energy laser 4 enables a simultaneous multiple-zone welding of cylinder inner face. |
