Technical enhancements of the rotary-draw-bending to a semi-kinematic process with reduced tool surfaces

将旋转拉伸弯曲技术增强为半运动工艺，并减少工具表面

• 批准号: 405331573
• 负责人: Professor Dr.-Ing. Bernd Engel
• 金额: --
• 依托单位: Lehrstuhl für Umformtechnik
• 依托单位国家: 德国
• 项目类别: Research Grants
• 财政年份: 2018
• 资助国家: 德国
• 起止时间: 2017-12-31 至 2020-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/405331573?language=en
• 关键词: Technical; enhancements; rotary; draw; bending

Rotary draw bending is a widely used method for bending profiles according to DIN 8586. The application spectrum of the process extends over a large number of geometries with a constant bending radius. These products can be used in a wide range of industrial and private applications. The rotary draw bending is a tool-bound forming process, in which the tool surfaces are determined by the cross section and the bending geometry (bending radius). A change of the semi-finished geometry (e.g. circumference respectively wall thickness) or the bending geometry (bending radius) require an adaptation and/or supplement of forming tools.In addition to bending of constant radii, free-form bending processes (e.g. the three-roll-push-bending) have the advantage to produce free bending contours without need of changing the tool geometries as they base on kinematic bending. The project has the superordinate goal to extend the tool-bound rotary draw bending process to a partial kinematic bending process, by tools with simplified geometries and additional tool axes. This gives the opportunity to serve future demands for enhanced flexibility of forming processes and the economic production of smaller quantities towards individualized products.A method for a systematic approach to reduce tool surfaces is not yet known. In the project, a method based on local and temporal variations of tool contacts for the reduction of the tool surfaces is investigated and tested. The tool contact is analyzed with FE simulations to examine the effects of the tools’ contact surfaces reductions. The generated surface elements are used as reduced tool surfaces. This method is applied to the rotary draw bending tools bending die, pressure die, clamp die and wiper die, respectively. After reducing the tools’ surfaces, it will be investigated to what extent the tools generated in this method influence the forming results compared to conventional tools.When considering contact normal stress development over the process time of forming, kinematic concepts could also be derived in which surfaces only have a temporary shaping effect.The main result is achieving a flexibilization of the rotary draw bending process. With a tool configuration based on a partly kinematic bending, it is possible to bend both, different bending radii and different tube dimensions by the suggested method.

旋转拉伸弯曲是一种广泛使用的弯曲型材方法，符合 DIN 8586 标准。该工艺的应用范围涵盖大量具有恒定弯曲半径的几何形状。这些产品可用于广泛的工业和私人应用。旋转拉弯是一种受工具约束的成形工艺，其中工具表面由横截面和弯曲几何形状（弯曲半径）决定，半成品几何形状（例如周长或壁厚）的变化。或者弯曲几何形状（弯曲半径）需要成形工具的适应和/或补充。除了恒定半径的弯曲之外，自由形式弯曲工艺（例如三辊推弯曲）还具有产生自由弯曲的优点轮廓无需改变工具几何形状，因为它们基于运动弯曲，该项目的首要目标是将工具绑定的旋转拉弯工艺扩展到部分运动弯曲工艺。这为满足未来增强成型工艺灵活性和经济生产个性化产品的需求提供了机会。减少工具表面的系统方法尚不清楚。研究并测试了一种基于工具接触的局部和时间变化的方法，通过有限元模拟来分析工具接触，以检查工具接触表面减少的影响。该方法适用于减少工具表面。分别使用旋转拉弯工具弯曲模具、压力模具、夹紧模具和修光模具，在减少模具表面后，将研究与传统模具相比，该方法生成的模具对成形结果的影响程度。当考虑接触时。成形过程中正应力的发展，也可以推导出运动学概念，其中表面仅具有暂时的成形效果。主要结果是通过基于部分运动弯曲的工具配置实现了旋转拉弯工艺的灵活性。 ， 这是可以通过建议的方法弯曲不同的弯曲半径和不同的管尺寸。