Packaging steel strip mill system under pressure

Packaging steel strip mill profile rolling mill under pressure down system is the main actuator, control the thickness of the past the use of electric pressure, the pressure motor through secondary cylindrical gear and worm gear and worm drive, drive down screws of roll gap adjustment, the first generation of HSM because do not consider AGC function, press down not only power system design is too small, and under the pressure of screw design on the pitch is too small, greatly reduces the transmission efficiency, make the motor static torque is too big, can't satisfy the AGC thick set the desired acceleration even unable to strip down. The second generation of strip cut thick performance put forward clear requirements for electric pressure, which requires pressure system has: pressure speed reaches 1. 2 - 1. 5 mm/s, press down the acceleration is greater than 2 mm/s2. For this pressure motor with low inertia, times the operating pressure, larger pressure screw pitch, press down between screw and the bearing seat with measures, such as thrust bearing, but electric pressure adjustable thickness under the following congenital weakness: ( 1) During frequent fluctuation adjustment, easy to cause pressure transmission mechanism of the wear and tear; ( 2) Dynamic response is still cannot meet the high frequency interference; ( 3) Will significantly slow motion when the rolling force is larger. Therefore, widely used in the modification of existing rolling mill electric pressure + fine tuning scheme of the hydraulic cylinder, the rolling schedule set electric pressure ( Empty load), and loading the thick with fine-tuning the hydraulic cylinder, in order to save investment, generally only after three or four frame to increase the hydraulic cylinder. Due to the hydraulic cylinder response almost 10 times faster than the electric pressure, thus greatly improving the adjustable thickness accuracy. With the development of hydraulic technology, in the 1980 s began to all new strip mills machine adopts full hydraulic pressure, namely long-stroke hydraulic cylinder, in addition to the electric voltage, and also on the roughing mill adopted this technology.