板带轧机厚度自动控制系统由哪几部分组成？AGC调整对钢板板形的影响？
参考答案：
板带轧机厚度自动控制系统由厚度的检测系统、厚度自动控制装置、执行机构组成。AGC的作用是控制钢板同板差，消除钢板水印和其他因素对厚度的干扰。但是由于AGC调节过程会加剧轧制力的波动（如在钢板水印处，轧制力增大，轧机弹跳值增大，为了控制钢板厚度，AGC系统会调节液压缸的油柱高度，使得辊缝值减少，从而轧制力变得更大）。这种波动会加剧钢板长度方向的凸度变化，如果凸度变化超过规定范围，钢板板形容易恶化。
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| A boy who was cleaning shoes in the street said to a young man 1 by, "Let me clean your shoes, 2 ?" The young man said, "No, thank you." "You may 3 me only a pound for that, sir." said the boy. 4 the young man refused again. Then the boy told him that he would clean his shoes for 5 . The young man agreed to this, and soon one of his shoes was shining brightly. The man put 6 shoe on the boy, but the boy refused to clean it unless he 7 two pounds for his work. The young man refused to pay anything and went away. But one looked 8 dirty that he couldn't walk away. He had to 9 and gave the boy 10 . In a very short time his shoes shone brightly. | ||||
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