关键词: 熔接；缺陷；电机齿轮盖；玻璃纤维；模流分析；强度；压溃力

Abstract: The motor gear cover of automobile wiper system is generally made by injection molding technology, and glass fiber is added into raw material to enhance strength of product. Taking the strength of screw hole of motor gear cover as the research object, firstly, the mold flow analysis software Moldflow is used to analyze the forming process of the original scheme, and it is found that there are weld marks on the edge of the screw hole, and the strength did not meet the design requirements combined with the torque test; then the design scheme is optimized and the screw hole is thickened by radial direction; finally, the assembly test and crushing force test are compared and verified before and after optimization. The results show that the supporting capacity is increased 100% when radial thickness is added by 2 mm, and the assembly torque is increased from 1.75 Nm to 2.1 Nm, which meet the design requirement and provide the refence for strength design of glass fiber enhanced material.

Key words: Welding; Defects; Motor gear cover; Glass fiber; Moldflow analysis; Strength; Crushing force