Comparative analyses off the deep drawing process with extended process kinematics

缩颈和起皱是拉深过程中失效的主要原因。到目前为止，已经测试了不同的方法来有效地利用材料的可变形性。高动态伺服压力机技术的发展，使得在压力机滑枕和模垫的可变路径中主动改变载荷的新技术得以实现。众所周知的脉动模垫技术扩大了成形极限。最近的一种方法是模垫和冲头同时脉动，称为缓冲-冲头-脉动。在初步的研究中，可以发现一些导致成形极限进一步扩大的效应。对于缓冲夯击脉动，对接触区域的应力条件和工艺参数的预测是不够的。今天，仍然缺乏适当的评价基础。例如，如果负载变化的幅度与整个工具和机器系统的间隙和弹性的顺序相同，则必须通过叠加振动在工艺设置中考虑这些决定质量的因素。在提议的项目中，一种评估单力项应使用的方法，允许在标准深拉深，缓冲脉动和新的缓冲冲击脉动之间进行直接比较，并澄清观察到的具有可变运动学的过程现象。

Necking and wrinkling are the main cases of failure in deep drawing processes. Different approaches have been tested so far to effectively exploit the deformability of the material. The development of high dynamic servo press technology enables the implementation of new technologies with active changes in loading during variable path of the press ram and die cushion. The well-known technology of the pulsating die cushion extends the forming limits. A more recent approach is the simultaneous pulsation of the die cushion and ram which is designated as a cushion-ram-pulsation. In preliminary investigations some effects could be shown which lead to a further extension of the forming limits. The knowledge of the stress conditions in the contact area and the forecast of the process parameters are insufficient for the cushion-ram-pulsation. Today an appropriate basis of evaluation is still lacking. For example, if the amplitudes of the load changes are in the same order as backlash and as elasticity in the whole system of tool and machine, these quality-determining factors must be taken into account in the process setup by superimposed vibrations. In the proposed project, a method for evaluating single-force-terms shall be used to allow a direct comparison between the standard deep drawing, the cushion pulsation and the new cushion-ram-pulsation and to clarify the observed phenomena of processes with variable kinematics.