芯棒参数对超薄壁管数控绕弯成形质量的影响

To improve the bending formation quality of ultra-thin-walled tube, the effects of the mandrel parameters, including number of mandrel ball, mandrel ball thickness, and mandrel support angle, on wall thickness variation and ovality are discussed. 21 differently combined mandrel support angle schemes are designed by combining three different mandrel ball thicknesses with seven different mandrel ball numbers. The results show that the number of mandrel ball exerts a certain influence on the wall thinning uniformity. For same number of mandrel ball, the smaller the mandrel ball thickness, the smaller the maximum wall-thinning ratio. The maximum wall-thinning ratio becomes larger as the mandrel support angle increases. with the increase in the number of mandrel ball, mandrel ball thickness or mandrel support angle, the ovality tends to reduce. It is concluded that the reasonable mandrel support angle for ultra-thin-walled stainless steel tube is ranged from θ/3 to θ/2.