| 摘要 |
PROBLEM TO BE SOLVED: To provide a pusher device with which thickness deviation in the top part of a tube stock manufactured by pusher piercing is suppressed. SOLUTION: The pusher device 4 is provided with a cylinder device 30 and a pusher mandrel 34. The cylinder device 30 contains a cylinder shaft 32. The pusher mandrel 34 is attached to the top of the cylinder shaft 32 and the top of the pusher mandrel 34 is brought into contact with the rear end of a billet 20. The cross-sectional area Sp of the pusher mandrel 34 and the cross-sectional area Sb of the billet 20 satisfy formula (1): 0.3≤Sp/Sb. Further, the length Lp of the pusher mandrel 34 and the cross-sectional area Sp of the pusher mandrel 34 satisfy formula (2): Lp/Sp≤1.2. The shifting distance Lc of the top of the cylinder shaft 32 when piercing and the outside diameter Dc of the cylinder shaft 32 satisfy formula (3): Lc/Dc≤45. COPYRIGHT: (C)2009,JPO&INPIT
|
