PURPOSE: To prevent he generation sticker phenomenon by calculating beforehand the axial speed of a blank material when the fiting to main rolls is completed and determining the axial speed of the blank material as the upper limit of the thrusting speed that a pusher exerts on the blank material.
CONSTITUTION: An electric motor 19 is operated to drive a pusher 17 by means of a pinion 20 and a rack 21, thereby pushing a blank material 14 into the space between main rolls 11. The blank material is pierced with a plug 13 to form a blank pipe. The material quality and size of the material 14 are inputted from a setter 27 for the specification of the blank material to a controller 26, the size of the blank material is inputted thereto from a setter 28 for the specification of the blank pipe and the sizes the set values of the respective parts of a piercer are inputted thereto from a setter 29 for piercing conditions. The controller 26 calculates the input values in accordance with the prescribed equation, sets an adequate thrusting speed and controls the driving voltage to be applied on the motor 19. The thrusting speed that the pusher 17 applies on the material 14 is determined at the axial speed of the blank material 11 when the fiting to the main rolls 11 is completed as its upper limit.
OKAZAKI SHIYUUJI
JPS52119459A | 1977-10-06 | |||
JPS5480262A | 1979-06-26 |