Auto Wiper Brush Spring Forming And Springback Control Research

Wiper brush spring is a significant component of windshield wiper system in auto. The quality level of the spring can affect wiping quality of the wiper brush in windscreen. Currently, most of the domestic wiper brush spring manufacturers produce the component with process of cam pressed material. Its unstable quality, low production efficiency and long design cycle makes it difficult to satisfy modern fast-changing market demand.Based on bending and shaping characteristics of the spring, this paper makes an analysis on spring distribution of stress and strain in bending process, and theoretically deducts calculation formula of bending moment and bending force in bending process. In regard to different material and different bending radio, simplified algorithm of bending moment and stress analysis algorithm are applied accordingly to calculate the bending moment figure and thus deducts the bending force with the combination of bending force calculation formula. Due to complexity of material bending and shaping process, which is usually accompanied with material internal structure changes such as neutral layer displacement, material dimension changes in bending zone, and distortion and crack in cross section, there is deviation between theoretical calculation and practical production. Thus the paper attempts to apply a new bending test device to measure bending force in different materials which are bended with different radius. Through a comparison between theoretical data and experimental results, the paper concludes that bending force deducted from stress analysis method is closer to experimental results with further revise needed to minify the deviation.Springback is an unavoidable defect in bending and shaping process. From metal forming principles, we understand that the elastic deformation of the material will disappear when external force is removed.Thus forms and angles in the workpiece will change. Firstly, the paper assumes resilience in workpiece is caused by additionally reverse bending moment, and deducts the springback accordingly. Then it monitors the bending and shaping process of workpiece with application of Dynaform and Autoform to calculate the springback and compare the data through monitoring and theoretical calculation. The comparison result shows theoretical data is smaller than monitoring data, which demonstrates that in resilience the materials is also affected by other factors such as material hardening.A research in bending and shaping of wiper blade spring and springback control provides an important reference to machinery development and operation design for spring production in the future.