| 摘要 |
PURPOSE:To optimize casting conditions such as cooling speed and drawing speed of a molten metal by providing a push back roll set which drives a billet in the push back direction and setting the driving force for drawing so as to exceed the driving force for push back. CONSTITUTION:The driving force acts intermittently on the billet in the direction of drawing the same at every forward and backward turning of an oscillating arm 15 by the operation of a driving mechanism 10 in the place of a drawing roll set 7. On the other hand, the driving force acts on the billet A always in the direction for pushing back the same in the place of a push back roll set 8. Said driving force is so set as to be smaller than the driving force for the intermittent drawing of the roll set 7. The billet is therefore drawn against the driving force for push back while the driving force for drawing acts on the billet. The movement toward the drawing direction of the billet by inertia is offset by the driving force for push back at the moment when the effect of the driving force for drawing ceases. The billet is then instantaneously stopped and is acted with the pressing force in the direction for pushing back the billet during the time until the succeeding driving force for drawing acts thereon after said cease. |
