LENGTH CONTROLLING SYSTEM FOR SEAMLESS TUBE ROLLING MILL

摘要

PURPOSE:To control the length of a tube directly during rolling by detecting the speeds of a rolling material in the inlet side and outlet side of a tube rolling mill, calculating the tube length and changing the press-down position so as to obtain the target value. CONSTITUTION:Target outlet side speed VAIM is calculated making the inlet side speed (v) taken in by an inlet rolling speed detector 60, and signals from an inlet side length storing device 90 that stores inlet side length (l) measured by weight or rolling prior to present material and a target elongation length storage device 100 that stores designated target elongation length LAIM input. Comparison is made with the outlet side rolling speed V inputted from an outlet side rolling speed detector 50, and timing of on/off control is detected. To make the tube length close to LAIM, control command is outputted to a press-down position controlling device 70 that changes clearance between rolls in accordance with timing from a lock-on detector 80.