Analysis of negative torque of wide and thick wear-resistant plate prestraightening machine
Wear-resistant plate products are important iron and steel materials necessary for the development of national economy, and are widely used in construction machinery, shipbuilding, bridge construction, cement mining and other national economic fields. In the process of seven rolls pre-straightening in Baosteel, continuous negative torque occurs in roll No. 6, which causes slip-off and straightening noise between the wide and thick wear-resistant plate and the straightening roll, and also causes vibration of the equipment, causing damage to the straightening roll surface. Among them, there are obvious vibration marks on the roll surface of roll 6, no vibration marks on the roll surface of roll 1 and 7, and slight vibration marks on the roll surface of roll 2, 3, 4 and 5.
Based on the actual deformation of wear-resistant plate, the researchers analyzed the causes of negative torque by studying the relationship between material deformation and bending curvature and bending deflection under each pass. At the same time, the test signal of transmission shaft torque in the seven-roll pre-straightening process is analyzed by strain bridge method and compared by finite element simulation.
The results show that the negative torque of the wear-resistant plate is caused by the uneven speed of the same speed provided by the centralized drive and the different bending amount. The negative torque causes the load torque of each roll to be redistributed, which eventually causes damage to the straightening roll surface. After the speed of the second motor is increased by 30%, the negative torque phenomenon of roll 6 is alleviated, the torque surge phenomenon of roll 3 and roll 5 is eliminated, the flatness of the straightening plate is improved, and the residual stress distribution after straightening is more uniform.
