| 摘要 |
PURPOSE:To stabilize melt cutting work and to form a hole exactly and easily by fixing a jig having a standard hole on a plate to be worked, fitting a space holder into the nozzle of a torch and moving the nozzle along the inside surface of the standard hole. CONSTITUTION:Straight lines l1, l2 intersecting with each other are marked off on the plate 10 to be worked such as a steel plate, and a jig 1 is positioned and fixed on the top surface of the plate 10 in the position where the index 6 of the jig 1 matches said lines. The annular part 8 of a spacer holder 7 is fitted in the nozzle 12 of a cutting torch 11. The support part 9 of the holder 7 is placed on the top surface of a plate-like body 3 on both sides of a standard hole 2, and while the outside circumferential surface of the nozzle 12 is brought into contact with the inside circumferential surface of the hole 2, the nozzle 12 is moved and the plate 10 is melt cut. The spacing between the forward end of the nozzle 12 and the plate 10 is maintained constant by the cooperative movement of the jig 1 and the holder 7 and the rolling of the nozzle 12 is prevented; therefore, the hole conforming to the hole 2 is formed exactly. |
