To provide a trimming method of a pipe end which can easily form an irregular-shaped trim end with a complex shape having sharp depths in the axial direction at the pipe end, requires the small number of man-hours for trimming, and is inexpensive in a facility cost.
The pipe end 232 is trimmed by a die 10 and a punch 25. The rectangular parallelopiped die 10 has a non-circular cross-sectional shape corresponding to a pipe 230, and is provided with an annular first cutting edge 16 curved corresponding to the irregular-shaped trim end on its external surface. The die 10 is inserted into a cavity of the pipe end 232. The rectangular parallelopiped punch 25 is provided with a second annular cutting edge 31 curved to sequentially engage with the first cutting edge on its external surface. The punch 25 is revolved around the external surface of the die while it is rotated around its axis. Thus the first cutting edge 16 and the second cutting edge 31 trim the pipe end 232 to form the irregular-shaped trim end 233.
UENO KOICHI
KUSANO AKIHIRO
TAIHO SEIKI CO LTD