JPS56168946A - Detection of abnormal contact of continuous casting roll with cast ingot - Google Patents

Abstract

PURPOSE:To detect abnormal rotation of a roll and thereby detect abnormal contact of the roll with an ingot by determining the actual rotational period with a rotation detector and comparing it with the reference rotational period or making mutual comparison. CONSTITUTION:An output signal of a rotational pulse oscillator 2 is inputted in an actual rotational period calculating circuit 5 and the time required for rotation of a roll 1, i.e. actual rotational period TM is calculated. On the other hand, ingot drawing speed V is detected with a well- known speed detector 6, and the reference rotational period (T=piD/V) is calculated in a reference rotational period calculating circuit 7 using the velocity V and known diameter of the roll D. Then, the actual rotational period TM is compared with the reference rotational period T in the comparison circuit 8, and if the difference is greater than a set value, this is indicated on an alarm indicator 9. When comparison of rotatonal period is to be made on plural rolls, output of actual rotational period calculating circuit 5, 5'... corresponding to each roll is changed successively by a changeover circuit 10 and inputted to the comparison circuit 8. When the actual rotational period of each roll is to be compared, the output of actual rotation calculating circuit corresponding to any two rolls are compared.