| 摘要 |
PURPOSE:To improve the yield of a tubular product by suppressing the extrusion top end of the billet as a solid bar body to get away into a solid stem from the die hole of a die stem, at the time of extrusion working the tubular product by piercing a solid billet through the pull-back type double acting indirect extrusion press. CONSTITUTION:After upsetting the solid billet 13 in a container 12, the die stem 11 and the container are moved to form a clearance corresponding to the margin for expansion of the billet between a seal brock 10 and the billet 13 and to pierce. In concrete term, a pair of movable platens 9, 16 are contraposed interposing a fixed platen 4, an extrusion force generator 1 and a piercing mandrel 7 are provided between one of the movable platen 16 and the fixed platen. The billet-containing container 12 and the extrusion die stem 11 are provided between the other movable platen 9 and the fixed platen. Furthermore, a lock gate 41 capable of getting in and out is disposed between one end of the container and one end of the fixed platen, the solid billet 13 is extruded to form as the tubular product. |
