The invention discloses a roll gap control method for a soft reduction technology for
continuous casting. The method comprises the following steps: respectively obtaining a displacement feedback
signal and an actual reduction force of an upper roll of a withdrawal and straightening unit by a displacement sensor and a
pressure sensor, and conveying the displacement feedback
signal and the actual reduction force to a compensator; performing pressure value compensation on the displacement feedback
signal so as to generate a corrected value, and transmitting the corrected value to a
comparator; comparing the corrected value with a set value for the roll gap so as to generate a comparison value; transmitting the comparison value to a position
regulator by the
comparator, adjusting opening of aservo valve and controlling a reduction force of a
hydraulic cylinder so as to adjust the upper roll connected with the
hydraulic cylinder so that the actual value and the set value for the roll gap are consistent with each other; and performing stepwise reduction by utilizing the upper rolls of a plurality of withdrawal and straightening units so as to reach total rolling reduction. In the method, by adopting the measure of pressure value compensation for the displacement feedback signal, the influence of
distortion of the displacement feedback
signal on the displacement sensor resulting from greater reduction force applied to a
casting blank can be eliminated, thus creating a good condition for achieving ideal metallurgical process effect by utilizing the soft reduction technology.