Method for designing stiffness of assistant spring in end part contact type few-leaf diagonal variable-cross-section main and assistant springs

The invention relates to a method for designing the stiffness of an assistant spring in end part contact type few-leaf diagonal variable-cross-section main and assistant springs, and belongs to the technical field of suspension steel plate springs. According to the method, the stiffness KAT of the assistant spring in the end part contact type few-leaf diagonal variable-cross-section main and assistant springs can be designed according to structural parameters of each main spring leaf, an elastic modulus, the length of the assistant spring and a design requirement value KMAT of combined stiffness of the main and assistant springs in the end part contact type few-leaf diagonal variable-cross-section main and assistant springs. Through instances and tests, the method for designing the stiffness of the assistant spring in the end part contact type few-leaf diagonal variable-cross-section main and assistant springs is correct; an accurate and reliable design value of the stiffness of the assistant spring can be obtained; a reliable technical basis is laid for designing the assistant spring in the end part contact type few-leaf diagonal variable-cross-section main and assistant springs; the design level, product quality and performance as well as vehicle driving smoothness of the end part contact type few-leaf diagonal variable-cross-section main and assistant springs can be improved; and meanwhile, the design and test expenses can be reduced and the product development speed can be increased.