| 摘要 |
PURPOSE:To permit grooving by means of a guide jig and a cutter, for example by driving a chisel by hammering with an air hammer onto the thick part of a heat-transmitting pipe expanded, and cutting said thick part along the axis center from inside. CONSTITUTION:A collared guide jig 5 equipped with a dovetail-groove-shaped guide groove 6 is inserted into the pipe edge part of an expanded heat-transmitting pipe 4. A chisel 7 having a V-shaped sheare point 8 is inserted into the guide groove 6. When said chisel 7 is driven by hammering with an air hammer (not shown in the figure), the expanded thick part is cut. Therefore, the heat- transmitting pipe 4 groove-cut is drawn-out from the insertion hole 2 on a pipe plate 1. |
