| 摘要 |
PURPOSE:To simultaneously form two pipes which are in conformity with the side surface of a predetermined pipe and have no thin wall part at the forward end by holding a pipe in a die, and by inserting a cutter formed therein with a pair of curved cutting edges and linear cutting edges projected from both sides of the curved cutting edge, into a through-hole formed in a die. CONSTITUTION:When a ram is lowered onto a pipe P set on a lower die 3a, an upper die 3b is pressed to clamp the pipe P. The ram is further lowered so that the apexes 15, 15 of curved cutting edges 12, 12 of a cutter 4 wedge into the top part of the pipe P, simultaneously, and therefore the pipe is cut in a substantially circular shape as viewed from above, by arcuated parts 17, 17 of the cutting edges 12, 12 and then is cut by rectilinear cutting edges 13 of the cutter 4 so as to cut down the side parts of the pipe P. The cutter 4 is lowered while the side parts are cut down and cut chips are pushed into longitudinal grooves 19. Due to the further lowering of the cutter 4, the cutting by the curved cutting edges 12 is again carried out in the lower half of the pipe P at the lower end of the latter on both side thereof and therefore the pipe P is completely cut. After the cutting, a pair of pipes P1, P2 are obtained, having arcuated parts A and right angle parts B at the ends thereof.
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