DEFLECTION CORRECTION DEVICE AND DEFLECTION CORRECTION METHOD IN BENDING MACHINE

PROBLEM TO BE SOLVED: To provide an angle as desired, by securing a sufficient deflection correction amount, by enhancing the pressure ratio of a crowning cylinder to a main cylinder, in a deflection correction for arranging the crowning cylinder.SOLUTION: A proportionality coefficient is calculated for calculating pressurization force of a deflection correction cylinder based on processing specification data, and a determination is made on whether or not its calculated proportionality coefficient exceeds an exhalation limit threshold value of the proportionality coefficient by which the pressurization force of the deflection correction cylinder and pressurization force of the main cylinder do not become an exhaled state, and when the proportionality coefficient exceeds the exhalation limit threshold value, a rate of an amount of exceeding the exhalation limit threshold value on the proportionality coefficient, is set as new deflection correction cylinder pressurization force by adding a multiplication value multiplied to a theoretical flexural load calculated based on the processing specification data to the pressurization force of the deflection correction cylinder, and the deflection correction cylinder is driven by its calculated new deflection correction cylinder pressurization force.