基于DEFORM-3D的新能源电池壳底部台阶镦挤成形工艺改进与优化

Improvement and optimization on upset-extrusion forming process for bottom step of new energy battery shell based on DEFORM-3D

以新能源4680系列电池壳为研究对象,为了保证密封效果,在电池壳底部设计了一种镦挤台阶结构,经过工艺试验验证,底部台阶成形需要预冲底孔、锻造成形、精冲底孔3步工序。针对底部台阶一次成形会产生毛刺等问题,在原工艺基础上提出了先锻造成形再整形的改进工艺,采用DEFORM-3D软件分别分析了两种不同工艺方案中底部台阶结构的成形效果和载荷变化情况。由于预制孔的直径尺寸对后续精冲孔影响较大,因此,设计了3种不同直径尺寸的预制孔,对其进行数值模拟,并根据成形规律和载荷变化以及底部预制孔成形要求进行比较、分析,选取最佳预制孔直径尺寸。结果表明:改进后的先锻造成形再整形工艺有利于降低模具载荷,使台阶结构的成形效果更好;预制孔直径为Φ8.5 mm时,载荷最小,更利于后续精冲孔工序的进行。最后,通过实际生产验证了改进工艺和优化结果的合理性。

For the new energy battery shell of 4680 series,in order to ensure the sealing effect,an upset-extruded step structure was designed at the bottom of battery shell,and after the process test verification,the forming of bottom step required a three-step process of prepunching of bottom hole,forging and fine-punching of bottom hole.Then,aiming at the problem of burrs in one-time forming of the bottom step,an improved process of first forging and then shaping was proposed based on the original process,and the forming effect and load change of the bottom step structure in the two different process schemes were analyzed by software DEFORM-3D.Furthermore,since the diameter of prefabricated hole had a great influence on the subsequent fine-punching hole,three prefabricated holes with different diameters were designed and numerically simulated,and according to the forming law and load change as well as the forming requirements of the bottom prefabricated hole,the comparison and analysis were conducted to choose the best prefabricated hole diameter.The results show that the improved process of first forging and then shaping is beneficial to reduce the mold load and make the forming effect of the step structure better.When the prefabricated hole diameter is 8.5 mm,the load is smallest,which is more conducive to the subsequent fine-punching process.Finally,the rationality of the optimization results and the improved process are verified by actual production.