| 摘要 |
<p>PURPOSE:To decrease the generation of a square bulge on an inside surface by controlling the circumferential speed of rolls so as to increase or decrease the stretch of a metallic pipe, namely so as to generate a relative speed between the circumferential speeds of the rolls and the speed of the pipe. CONSTITUTION:The pipe is meshed with the respective stands of a stretch reducer body 1 for, for example, 5-stand rolling. The rolling load during rolling, the torque of each stand and the rolling speed of the pipe are measured by load meters 2, torque meters 3 and speedometers 4 and the information thereon are fed to a computer 6. The rotating speeds of the rolls are measured by roll rotating speedometers 5 and are fed to the computer 6. The computer 6 determines the controlled variable of the number of revolutions of the rolls by the signal fed therefrom and feeds an output signal to the body 1 to control the circumferential speeds of the rolls so as to increase or decrease the stretch (tension) of the metallic pipe, thereby decreasing the generation of the square bulge on the inside surface.</p> |
