Abstract: The shape of the end of window trim strip is complex, the dimension is about 1000mm×30mm, the thickness is about 1mm, and the cross section in the width direction is narrow, which is a complex variable curvature convex section. The uneven fillet radius defect appeared at the end of window trim strip in the flanging process severely influenced its surface quality. Through simulations and tests, it is found that when the die radius is reduced, the defect of uneven fillet of the window trim strip is improved to some extent, but it has not reached the ideal index. Based on this conclusion, a die with variable fillet radius is designed to solve this problem and raised its design procedure. This die can solve this defect by reasonably arranging the die fillet radius. The fillet radius of the die is smaller in the center and gradually increases from center to corner. The simulation and test results showed that this method remarkably reduces the difference and variance of the fillet radius in different cross-sections of window trim strip.

Key words: window trim strip, uneven fillet radius, curved flanging, mold design