Development of an Incremental Tool Concept on the Basis of Rotating Tools for Sheet Metal Forming

旋转喷丸成形(RPF)是一种新型的板材成形新工艺。其成形特性与喷丸成形(SPF)相当。这种渐进成形过程使用围绕轮毂旋转的冲击器。在旋转过程中，冲击器在向心力的作用下稳定并保持在圆形路径上。对工件表面的冲击会导致局部塑性变形，从而导致工件的宏观曲率。诱导比能随冲击器的转速、冲击角和长度的不同而变化。与喷丸成形一样，可以通过调整进给速度和转速来改变固体率。开发RPF工艺的目的是避免与喷丸成形工艺相关的缺点，即投资成本高、能源效率低、工艺控制部分困难、路径重叠、喷丸材料量大。这反过来又导致了一种高效且灵活的喷丸成形替代方案。第一个资助期的主要目标是对工艺有一个基本的了解和开发新的工具概念。事实证明，IBF喷丸成型机转塔上最初计划的结构不适合作为刀架，因为它对振动的反应过大。因此，已经实现了一种实验装置，它允许对不同的工具概念进行准确的比较。然而，由于行驶距离有限，这种装置不适合生产面向应用的部件。在本提案所述的第二个资金期内，将建造一个面向应用的装置。该设置应考虑到减少加工时间和生产复杂的工件几何形状。因此，计划对现有的工业机器人进行改造，以便可以在机器人臂上安装不同的工具概念。因此，由于可提供多达六个空间自由度，因此可以非常灵活地成形工件。此外，第一个资助期已经开发的工具概念将针对这一设置进行优化，并必须开发安全和可重复的过程控制。随后，将生产面向应用的零件，以展示旋转喷丸成形的能力。

Rotary Peen Forming (RPF) is a new and innovative process for the forming of extensive sheet metal structures. The forming characteristics are comparable to shot peen forming (SPF). This incremental forming process uses impactors that are rotating around a hub. During rotation the impactors are stabilized and held on the circular path by the centripetal force. An impact on the workpiece surface induces localized plastic deformation which leads to a macroscopic curvature of the workpiece. The induced specific energy varies depending on the rotation speed, angle of impact and length of the impactors. In the same way as in shot peen forming the solidity ratio can be varied by adjusting the feed rate and the rotation speed.The aim of developing the RPF process is to avoid the process related disadvantages of shot peen forming, i.e.- high investment costs- low energy efficiency- partly difficult process control with overlapping paths- high amount of peening materialThis leads in turn to a highly productive and flexible alternative to shot peen forming.The main goals of the first funding period were the acquirement of a fundamental understanding of the process and the development of new tool concepts. It turned out that the originally planned construction on the turret of the IBF shot peen forming machine is not suitable as a tool holder, as it excessively reacts on vibrations. Therefore, an experimental setup has been realized, which allows an exact comparison of different tool concepts. Nevertheless, due to limited traveling distances this setup is not suitable for the production of application-oriented components.In the second funding period described in the present proposal an application-oriented setup will be constructed. The setup should allow for a reduction of process time and the production of complex workpiece geometries. Therefore the modification of an already existing industrial robot is planned, so that different tool concepts can be mounted on the robot arm. Thus, a very flexible forming of workpieces is possible because of the availability of up to six spatial degrees of freedom. Furthermore, the already developed tool concepts from the first funding period will be optimized for this setup and a safe and repeatable process control has to be developed. Subsequently, application-oriented workpieces will be produced which demonstrate the capabilities of Rotary Peen Forming.