MANUFACTURE OF SEAMLESS ECCENTRIC REDUCER TUBE JOINT

摘要

PURPOSE:To manufacture a titled tube joint free from thickness deviation, wrinkle and irregular tube end efficiently and economically by deep drawing a circular metallic plate and upsetting it using an eccentric die, and further making redrawing. CONSTITUTION:A circular metallic plate 10 having t0 thickness and d0 diameter is deep drawn using a punch 11 and a die 12 and a bottomed cylindrical concentric container 13 is obtained. This container 13 is set to an eccentric die 16 and downward force is applied by a presser 18 from the end face 17 of an opening, and a roughly formed eccentric container 23 which has no thickness reduction in the small diameter part 22. Next, with the container 23 attached to the die 16, an eccentric punch 24 is lowered, and straight wall side of the small diameter part 22 is formed to obtain an eccentric container 26 that has a specified small diameter part 25. If required, the bottom part is cut off after redrawing and edge preparation is made to both ends of the tube.