锥形管连续无模拉拔速度控制模型的理论与实验分析

基于金属体积非压缩性原理建立了锥形管连续无模拉拔速度控制模型,分析了无模拉拔变形过程中拉拔速度等工艺参数对变形区体积以及锥形管形状和尺寸的影响,并进行了实验验证.结果表明:拉拔速度不仅与进料速度、坯料尺寸、拉拔后锥形管的形状和尺寸有关,还与冷热源距离等工艺参数有关;拉拔速度随时间呈非线性增加;随着拉拔速度的增大,变形区的体积减小;冷热源距离越长、进料速度越大,变形区体积变化越大;当速比一定时,减小进料速度、增大冷热源距离,可以减小锥形管形状和尺寸误差、提高控制精度.

Theoretical and experimental analyses of a speed control model for continuous dieless drawing process of tapered pipes

A speed control model for continuous dieless drawing process of tapered pipes is established on the basis of the volume incompressibility principle of metal. The effects of drawing speed and other deformation process parameters on the volume of the deformation zone and the size of the tapered pipe were analyzed and verified by experiment. The results show that the drawing speed is related to the feed speed, the size of the blank pipe, the size of the tapered pipe and the hot-to-cold source distance. The drawing speed increases with time non-linearly. With an increase of drawing speed, the volume of the deformation zone declines;but with the hot-to-cold source distance lengthening and the feed speed increasing, the volume of the deformation zone changes significantly. When the proportion of feed speed to drawing speed is fixed, reducing the feed speed and enlarging the hot-to-cold source distance can reduce the dimension error and increase the control precision.