Coiling Profile Estimation with Compensation for Setting Deformation

The automotive industry has recently increased emphasis on the control of a coil spring's load axis to reduce sideforce in a suspension system. Reduced sideforce improves ride comfort. A coil spring's shape, or profile, is the main contributing factor in sideforce control. After a spring's final profile is designed, a coiling profile must be determined which accounts for the setting process of the spring. Setting of helical coil springs is a common practice for inducing beneficial residual stresses in a spring cross section. This reduces later sag and settling of the spring. Finite element methods for the prediction of coil profiles are not suitable because of manufacturing process complexity and difficulty in practice. A new approach utilizing system engineering is proposed. The development of the approach and its application to stress and profile prediction are presented. An example demonstrates the attractiveness and accuracy of coil profile prediction with this new approach.