Analysis And Improvement Of Tail-Gate’s Sag Of SUV

Due to the special shape and structural design of SUV, the spare tire is usually mounted on the tail-gate, and the tail-gate bears a disproportionate load. A number of SUV tail-gates sag which would affect the normal opening and closing of the tail-gate. In order to solve the problem, some assistant device has been installed on the SUV, and some spare tires are installed inside the car at last. In this paper, the computer simulation technology combined with the experimental method was used to solve the SUV tail-gates sag, and in-depth analysis of the reasons for SUV tail-gates sag has been conducted. Then, the improvement of the problem was presented.In order to obtain the stiffness characteristics of the SUV, this paper conducted the bending and torsion test of the body-in-white, frame and body-white combined a frame. The deformation distribution curves of these structures under loads have been obtained through the test. In addition, a load was applied on the tail-gate with different angle to obtain the deformation data of the tail-gate. The test results provide a support for validation of the tail-gate sag simulation model and the simulation analysis.The finite element model of the body-in-white and frame of a SUV were developed using the Hypermesh and ANSYS software. Based on the model of the body-in-white and frame, a special model which was against on the SUV tail-gates’ sag problem was built. A detailed analysis of the reasons for SUV tail-gates’sag was conducted and the improvement of the structure to solve the corresponding problem was discussed. At the same time, in order to improve the loading status of the tail-gate and body-in-white, a new tailgate-oriented device, which can provide a reliable support for the tail-gate, was presented. Thus, the phenomenon of the tail-gates sag was reduced effectively.Two vehicles were measured by three dimensional measuring machines and the real world road test was conducted to analyze the deformation distribution characteristics of body structure. Besides, the validity and feasibility of the improvement has also been validated according to the real world test.