Fatigue test device for automobile three-order gradually-changing-stiffness steel plate spring

A fatigue test device for an automobile three-order gradually-changing-rigidity steel plate spring comprises a gantry crane assembly, a two-order auxiliary spring collision stopping mechanism, a power mechanism, a connecting mechanism and a workbench, the gantry crane assembly is fixed to the workbench, a three-order gradually-changing-rigidity steel plate spring assembly is hoisted below the gantry crane assembly, the two-order auxiliary spring collision stopping mechanism limits a two-order auxiliary spring, and the two-order auxiliary spring collision stopping mechanism is connected with the power mechanism. The power mechanism drives the three-order gradual rigidity steel plate spring assembly to move up and down and comprises an ejector rod and vertical guide antifriction sleeve assembly, a motor assembly and a flywheel crank connecting rod mechanism assembly. As the above structures are integrated to form the rack for simulating the whole-vehicle real-vehicle motion state of the plate spring, not only c