PURPOSE: To form the leaf spring of good spring loading accuracy by respectively adjusting the distance for moving the roller which decides the roller pressurizing force and the bending angle for the spring formed part, and the fixing position for the material to be worked.
CONSTITUTION: The mechanical property and the shape for the material to be worked are measured before forming the spring, and the working condition is decided considering the above value. The position for fixing the material to be worked and the moving distance of the roller 2 which decides the bending angle for the spring formed part are decided with the above value, further the working pressure required to work is decided. These decisions are executed with the calculating and controlling means based on the measured data. Then the pressurizing force is applied to the material to be worked 3, this pressurizing force is always detected and the pressurizing force is controlled so as to increase and to decrease or to keep to the set value based on the detected value. Therefore, the products having the accurate spring load is realized with only one working compared to the products requiring the correction other than the correction of the shape of sheet thickness, etc., or the products being unpossible to work because the bending angle is not enough due to the restriction of shape.
UENO SHIGEYASU
TAKAHASHI MICHIRO
UMAGOE YUKIMORI
MORITA SEIJI
