Jiangyin Hongfeng Plastic Industry Co. , Ltd. , Wuxi Jiangsu 214422, China
Abstract: The tighten failure problem of self-tapping screw in rearview mirror base assembly and subsequent assembly was analyzed. The
influence of screw hole aperture, installation torque, environmental factors and materials on the tighten failure of the self-tapping screw was
mainly studied. The research shows that when the rearview mirror base is assembled with self-tapping screw and the installation torque is
2. 93 N·m, and the screw hole aperture is 5. 3 mm, the sliding torque reaches the maximum value, and the product does not have screw
column crack and stripping problem. When the installation torque is 2. 93 N·m and the screw hole aperture is 5. 3 mm, the sliding torque
decreased by 15. 23% after the product was placed in the laboratory environment for 42 days. With the increase of injection temperature, the
sliding torque of the product decreases and even cracks, and the tensile strength, bending strength, bending modulus and notch impact
strength of the material decrease significantly.
Keywords: external rearview mirror base; self-tapping screw; screw hole; crack; stripping torque
-written by Dong Xue
