汽车覆盖件的特点是生产量大、质量要求高、材料薄、形状复杂、多为立体曲面、结构尺寸大。由于覆盖件的结构、模具的质量、工艺的安排等等都会影响覆盖件在生产试模中出现各种质量问题。一、解决覆盖件由反拉延成形时产生的裂纹与缩颈覆盖件在拉延时板材紧紧地包在凸模上,反拉延时成形的形状是依靠材料的变薄 Automotive cover is characterized by large production volume, high quality requirements, thin materials, complex shapes, mostly three-dimensional surface, the structure of large size. Due to the structure of the cover, the quality of the mold, the arrangement of the process, etc., all affect the quality problems of the cover in the production of test patterns. First, to solve the cover formed by the anti-drawing cracks and necking generated when the cover plate in the drawing tightly wrapped in the punch, anti-drawing the shape of the delay is dependent on the material thinning