摘要 |
PROBLEM TO BE SOLVED: To provide a processing method for a pipe with a grooved inner surface which prevents rupture of the pipe when grooving starts or even during grooving. SOLUTION: A floating plug 12 and a grooved plug 13 to be relatively rotatably connected therewith through a connecting shaft 14 are inserted into a tube stock 18. The tube stock 18 is subsequently subjected to diameter reduction processing through a holding die 11 and a plurality of roll-processing balls 15, and the floating plug 12 is fitted to the holding die 11, thus the grooved plug 13 is located at a position where the plurality of the roll-processing balls are arranged. The inner surface of the tube stock 18 is pressed to the grooved plug 13 by the plurality of the roll-processing balls 15, thus the grooved shape of the grooved plug 13 is transferred to the inner surface of the tube stock 18. A flaring plug 1 is arranged on the connecting shaft 14 between the floating plug 12 and the grooved plug 13 and then the inner surface of the tube stock 18 is grooved. COPYRIGHT: (C)2004,JPO
|