闭式冷弯成形辊花设计映射数学模型及实验研究

MAPPING MATHEMATICAL MODELLING AND EXPERIMENTAL STUDY FOR ROLL FLOWER DESIGN IN CLOSED COLD ROLL FORMING

针对金属闭式冷弯成形的多道次孔型轧制特点,考虑轧前管坯的轮廓与轧后异型管的轮廓存在拓扑等价关系和边界域的不动点性质,以双圆弧插值函数描述异型管的复杂轮廓,建立两者之间的形心映射数学模型,实现各道次孔型设计,绘制异型管闭式冷弯成形过程的辊花图。以铝合金圆管为坯料在试验轧机上进行了扇形管冷弯成形轧制实验,结果表明:轧后的扇形管内外轮廓变形柔顺且无凹凸点,壁厚偏差小于±0.5 mm,角部误差小于±1.5°,满足GB/T 6728-2002国标要求,研究结果为异型管冷弯成形的轧辊辊花设计提供了一种新方法。

According to the multi-pass groove rolling characteristics of metal closed cold roll forming, complex contour of shape tubes was described with the biarc interpolation function. The description considered the existence of topological equivalence relations and the fixed point property of the boundary region between the round tube billet contour before rolling and the shape tube contour after rolling. The centroid mapping mathematical model was established between them. The roll flower of closed cold roll forming process of shape tubes was drawn. The cold rolling experiment of the scallop tube was carried out on the test mill using the aluminum alloy round tube as the blank. The results show that the inner and outer contours of the scallop tube are compliant without bumps after rolling. The wall thickness deviation is less than ±0.5 mm, and the angle error is less than ±1.5°. They meet the requirement of the GB/T 6728-2002 standard. The study provides a new method for the roll flower design of the cold roll forming of shaoe tubes.