| 摘要 |
PURPOSE:To eliminate the need for leaving a rear end of a billet as a extrusion residual material by providing the discharging path of the surface layer of a billet between a container and die and by discharging to the container outer part the billet surface layer with the extrusion of the billet by placing it inside the container. CONSTITUTION:The first billet B1 is placed inside a container 2 without subjecting to a scaling and held at the prescribed temp. The material M on the surface layer including the billet shell consisting of oxides and to which dirts, etc. are stuck thereon is discharged to the outer part of the container 2 through the billet surface layer discharging path 6 of a die plate 3 when the billet 1 is pushed to the front part by an extruding stem 1. On the other hand the material excepting the surface layer of the billet B1 comes into the extrusion aperture 4a of a die 4 and is pushed out of the front end thereof as a shape material S. And when the extrusion residual length of the first billet B1 becomes in the prescribed length, the advance of the stem 1 is stopped. The second billet is thereafter inserted by the stem 1 into the container 2 by pushing out the stem 1 from the container 2 with its retreating once.
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