| 摘要 |
PURPOSE:To form the leak-proof outer tube of a high pressure metal vapor discharge lamp, by depressing one side of its exhaust pipe toward an internal direction, welding the side to aninner face of the other side, flatly press-crushing this welded part and forming a sealed part. CONSTITUTION:In a state with pressure in an exhaust pipe 7 lower than the atmospheric pressure, one side of the exhaust pipe 7 is heated by a burner and softened, then depressed by suction toward an internal direction to form a welded part 12 in the other side. A half position of this welded part 12 is further heated by the burner and softened then flatly press-crushed to form a press-crushed part 13 so as to obtain enough thickness with mechanical strength not short by pincers from a right angle direction for a welded direction, then a half position of the press-crushed part 13 is cut off by a cutter to form a sealed part. The one side of the exhaust pipe 7 can be welded in a manner with a change of its thickness in very smoothness and thickness almost without relating to dispersion of its diameter or thickness, consequently a distortion is never left in the welded part 12. |
