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

旋转喷丸成形（RPF）是一种广泛的钣金结构成形的新工艺。成形特性可与喷丸成形（SPF）相媲美。这种渐进式成形过程使用围绕轮毂旋转的冲击器。在旋转过程中，冲击器被向心力稳定并保持在圆形路径上。对工件表面的冲击引起局部塑性变形，从而导致工件的宏观曲率。诱导比能的变化取决于旋转速度、冲击角度和冲击器的长度。与喷丸成形一样，可以通过调节进给量和转速来改变固体比。开发RPF工艺的目的是为了避免与喷丸成形工艺相关的缺点，即-高投资成本-低能源效率-部分难以控制的重叠路径-大量的喷丸材料，这反过来导致了一个高效率和灵活的替代喷丸成形。第一个资助期的主要目标是获得对过程的基本理解和新工具概念的开发。结果表明，原计划的IBF喷丸成形机的炮塔结构不适合作为刀架，因为它对振动反应过度。因此，实现了一个实验装置，可以对不同的刀具概念进行精确的比较。然而，由于移动距离有限，这种设置不适合面向应用的组件的生产。在本提议所述的第二个供资期间，将建立一个面向应用的机构。该设置应允许减少加工时间和生产复杂的工件几何形状。因此，计划对已有的工业机器人进行修改，使不同的工具概念可以安装在机器人手臂上。因此，工件的非常灵活的成形是可能的，因为可获得多达六个空间自由度。此外，从第一个资助期开始已经开发的工具概念将针对该设置进行优化，并且必须开发安全且可重复的过程控制。随后，将生产出展示旋转喷丸成形能力的面向应用的工件。

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.