随动辊压型低应力精密断料教学实验平台开发

Development of a teaching experimental platform for low-stress precision cropping of follow-up roller press

为了增强学生对先进成形装备及低应力精密断料技术的理解,开发了随动辊压型低应力精密断料教学实验平台。该实验平台综合利用机械设计、传感器技术及计算机控制技术,将应力集中效应和随动辊压技术引入管料的精密分离断料工序中,设计了管料断面质量评价方法,对带有V型槽的45#钢及304不锈钢管料进行了裂纹可控式低应力精密下料实验,验证了断料效果。该实验平台不仅使低应力断料过程更加直观,还提升了学生对低应力精密成形技术的认识,增强了学生对“机械制造工程基础”“切削原理与刀具”及“先进制造技术”等课程的学习兴趣。

[Objective]To enhance the understanding and interest of students in advanced forming equipment and low-stress precision cropping technology,a low-stress cropping method is designed based on the fatigue crack propagation technology and a teaching experimental platform for follow-up roller-type low-stress precision cropping is developed.The proposed method can also address the problems of high energy consumption,severe material waste,low production efficiency,and high production costs associated with traditional cropping methods.Moreover,the proposed experimental platform integrates mechanical design,numerical simulations,sensor technology,and computer control systems to introduce stress concentration effects and follow-up rolling technology into the precise separation and cropping of tube materials.[Methods]The core of the proposed method is innovatively designed to comprise a follow-up rolling loading module with a spiral-lifting precision swing ring.The influence of existing nonfollowing and follow-up loading dies on the low-stress cropping effect is qualitatively analyzed from a mechanistic perspective.Throughout the dynamic loading of metal tubes,variations in the follow-up angle can be continuously realized for the follow-up rolling loading module in the range of 0°~15°,which is in accordance with the deflection law of different tube specifications.Furthermore,close contact between the outer circumferential surface of tubes and rolling loading can be satisfactorily realized.A method for evaluating the cross-sectional quality of tube materials is designed,and crack-controlled low-stress precision cropping of#45 steel and 304 stainless steel tubes with a V-shaped notch is performed.[Results]Compared with the hydraulically compensated loading method,the proportions of the inner ring tearing area,maximum protrusion height,and maximum depression depth of the 304 stainless steel tube are reduced by 19.20%,25%,and 50%,respectively.Furthermore,its average cropping time decreases by 12.19%.The proportions of the inner ring tearing area,maximum protrusion height,and maximum depression depth of the#45 steel tube are reduced by 21.63%,60%,and 33.33%,respectively,with the average cropping time decreasing by 18.19%.Compared with the traditional hydraulic compensation cropping equipment without a follow-up rolling function,our follow-up rolling precision cropping experimental platform substantially improves the cross-sectional quality of selected materials and considerably decreases the cropping time.[Conclusious]This experimental platform not only enhances the effectiveness of low-stress cropping but also improves students’interest in learning courses such as mechanical manufacturing engineering fundamentals,cropping principles and tools,and advanced manufacturing technology.