Abstract: In recent years, in order to realize energy conservation and emission reduction, lightweight has been the research direction and theme in the automobile industry. This paper aims to discuss how to develop a low-cost lightweight technology solution for automobile exterior. In this paper, through the study for product material structure mechanics, combine auto exterior parts’ force analysis, make sure the direction of the product structure design, and then choose the reasonable process and material with corresponding characteristics, under the premise to guarantee the basic strength and rigidity properties, the object is to investigate how to realize the light-weight effect. The technology involved in this paper mainly makes use of grade A-class quality surface characteristics of SMC material and good weathering and chemical resistance, to be used as the outer skin of multilayer material, SMC can also be designed for different thickness according to the needs of different position structural strength. Then we select multi-layer honeycomb sandwich structure as backside reinforcement part, which choose honeycomb hollow material as core material, glass fiber reinforce and polyurethane foam as reinforcement layer, so that the backside reinforcement combined with the light-weight, high strength, high stiffness characteristics of honeycomb sandwich structure, so can reach to light-weight, high strength, high stiffness of large automotive exterior accessories. Examples prove that by using this lightweight process of car exterior parts, the weight loss of SMC process products with the same stiffness is reduced to 40%~50%. In addition, this paper also elaborates the production process of the lightweight technology and the technical key points of the technology structure.

Key words: honeycomb sandwich, sheet material composite, polyurethane foaming, light-weight, automobile exterior part, stiffness