Thickness control method of aluminum plate hot mill adopting electric and hydraulic screwing down

Abstract

The invention mainly belongs to the technical field of metal pressure machining, and particularly relates to a thickness control method of an aluminum plate hot mill adopting electric and hydraulic screwing down. The thickness control method comprises the steps that firstly, the rolling force of the last two passes is set to be close, after rolling of the last but one pass is completed, a roll gap is kept unchanged, the electric screwing down bounce amount, the average roll gap and the average rolling force in the rolling process of the pass are calculated, and the average rolling force is used as the target rolling force of the last pass; then, in combination with manual measurement thickness, a target roll gap and a pre-swing roll gap before biting of the last pass are calculated, and a screwing down mechanism achieves execution in place; and in the rolling process of the last pass, through comparison of the actual rolling force and the target rolling force and deviation of the actual roll gap and the target roll gap, the outlet thickness deviation is calculated in real time in combination with a bounce equation, closed-loop control is put in, and therefore thickness precision is guaranteed. According to the thickness control method, under the condition of not depending on a thickness gauge, the thickness of the single-rack aluminum plate hot mill adopting electric and hydraulic screwing down can be precisely controlled.

Description

technical field [0001] The invention mainly belongs to the technical field of metal pressure processing, and in particular relates to a method for controlling the thickness of an aluminum plate hot rolling mill by electric and hydraulic pressure. Background technique [0002] The adjustment of the roll gap of the rolling mill needs to be realized through the automatic position control (APC, Automatic Position Control) system of the rolling mill. APC is the main actuator of automatic thickness control (AGC, Automatic GaugeControl) in the strip production process. It is divided into three types: full electric, full hydraulic, electric and hydraulic in terms of the source of rolling force. Such as figure 1 As shown in the figure, the ordinate S represents the roll gap of the rolling mill, the abscissa t represents time, and S a Indicates the average roll gap of the slab during rolling; S r Indicates the set roll gap; S b Indicates the actual no-load average roll gap before ...

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Problems solved by technology

[0004] In terms of existing papers and patents, the paper "Analysis of Positive Feedback Characteristics of Pressure AGC" (Steel, 2007, 42(7): 51-55) analyzed conventional pressure AGC and pointed out that due to the stiffness coefficient C of the rolling mill and the plasticity coefficient of the rolled piece Q cannot be obtained accurately, and there is a positive feedback area in the pressure AGC, so it is impossible to accurately control the thickness

The patent "Strip Rolling Thickness Control Method Based on Rolling Mill Bounce Characteristic Curve" invented a thickness control method based on rolling mill bounce curve. The thickness calculation method adopted is a fixed expression based on the regression of pressing data. Since the pressing process is the full roll surface contact of the upper and lower work rolls, that is, the contact length of the work rolls is the same as the length of the work rolls, while the upper and lower work rolls are in contact with the strip during rolling, that is, the contact length is the same as the width of the strip, and the width of the strip is It is less than the length of the work roll, and different products have different requirements on the width, which leads to the difference between the spring of the rolling mill during pressing and rolling. The invention uses a fixed empirical model to consider the influence of strip width, which is not accurate enough ; Simultaneously, the characteristic of rolling mill also is constantly changing in rolling process, can cause the change of rolling mill rigidity and actual roll gap such as roll thermal expansion and roll wear, and above-mentioned invention also can't solve this problem; Moreover, its control adopts pure proportional method, Unable to quickly eliminate the thickness difference

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