# How to control the thickness of oil film in the thickness control system of tandem cold rolling mill

2022-03-04

For high-precision automatic cold rolling mill thickness control technology, foreign countries have reached a high level, and China has achieved some results in this regard, but there is still a gap compared with developed countries. Therefore, professional equipment manufacturers have studied the influence of the thickness of oil film roll on the thickness of strip steel, and studied the corresponding compensation control method of cold rolling mill according to the change of relative oil film thickness, The thickness compensation control is studied theoretically.
In the process of research, firstly, the influence of oil film thickness on cold rolling thickness is proposed. When the rolling speed increases, the thickness of cold rolling decreases, and vice versa. According to various models of oil film thickness algorithm, two algorithms are provided for the relative thickness of oil film. It uses the improved formula of equation to compensate the oil film thickness, and uses the measured data to reduce the coefficient according to the least square method, The oil film thickness and measured value are used to adjust the data according to the modified formula of the rolling mill manufacturer. It can be seen that the adjustment degree is very good.
The compensation value of the oil film thickness of the actual system is obtained by using the look-up table and interpolation method. The relative oil film thickness algorithm is used to create conditions for the corresponding research of the thickness control algorithm. Considering that the thickness control system of oil film thickness compensation adopts the closed-loop control of roll space, and the closed-loop thickness control is combined with the oil film thickness compensation structure, which is finally applied to different types of cold rolling mills, With higher precision and more stable belt, the rolling thickness performance of steel.
Finally, the thickness compensation control of acceleration and deceleration is studied. The first is the direct calculation method, which includes the direct construction of nonlinear equations through the rolling theoretical formula, and the second is the implicit function derivation method, which includes using the formula derivation method to obtain the relationship between the spatial adjustment amount and acceleration between rollers, and then adjust the space between rollers. This method is convenient to apply, A thickness compensation control system is established.