Fundamental investigations on the effect of structured functional surfaces of milling tools regarding process dynamics

铣削刀具结构化功能表面对工艺动力学影响的基础研究

• 批准号: 426468684
• 负责人: Professor Dr.-Ing. Dirk Biermann
• 金额: --
• 依托单位: Institut für Spanende Fertigung
• 依托单位国家: 德国
• 项目类别: Research Grants
• 财政年份: 2020
• 资助国家: 德国
• 起止时间: 2019-12-31 至 2022-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/426468684?language=en
• 关键词: Fundamental; investigations; effect; structured; functional; Fundamental; investigations; effect; structured; functional

The productivity of machining processes is often limited by the occurrence of dynamic effects such as regenerative chatter. Five options to influence the process dynamics are defined in literature: The enhancement of the system stiffness and system damping, the process parameter selection, the process damping maximization, and the regeneration disturbance. Increasing the stiffness or damping of machine tools constitutes a challenge in engineering and design processes, is associated with high costs and restricted in terms of scalability. An optimized process design and parameter selection require a detailed determination of the dynamic properties of the production system and extensive expert knowledge in the field of process dynamics. Maximizing process damping and disturbing the regenerative effect is largely independent of the general conditions of the production system and process, which is why these methods are particularly interesting in the sense of a universally applicable strategy for increasing productivity. The presented project approach intends to damp or disrupt regenerative chatter vibrations by applying a defined structure on the minor functional surfaces of a milling tool. According to the working hypothesis, these structures should, for example, absorb transverse forces, direct the cutting motion or cause friction effects and thus counteract dynamic deflections. Using experimental investigations, the potential of process-stabilization of a defined functional surface structuring could be demonstrated. The flank face of the minor cutting edge of an HSS milling tool was prepared with circular structures, applied in milling operations and evaluated regarding the experimentally determined stability limit. A spindle speed-independent increase of the process stability and productivity of up to 60% could be achieved. The aim of the project initiative is to conduct fundamental research on the causal relationships between structural designs and process dynamics. For this purpose, an analog experimental rig is going to be developed, which reduces the complexity of the chip formation process from milling to an orthogonal cut. Dynamic deflections are represented by a defined excitation of the oscillating tool system. Within the scope of fundamental investigations, the influence of various structural features on the chip formation process will be measured and analyzed. In addition, selected structural variants are going to be transferred to rotationally symmetrical milling tools and subsequently applied and evaluated with regard to their potential for process stabilization in milling operations.

加工过程的生产率通常受到动态效应（例如再生聊天）的发生限制。影响过程动态的五个选项在文献中定义了：系统刚度和系统阻尼的增强，过程参数选择，过程阻尼最大化以及再生干扰。增加机床的刚度或阻尼是工程和设计过程中的挑战，与高成本相关，并且在可扩展性方面受到限制。优化的过程设计和参数选择需要详细确定生产系统的动态属性以及过程动态领域的广泛专家知识。最大化过程阻尼和干扰再生效应在很大程度上独立于生产系统和过程的一般条件，这就是为什么这些方法在提高生产率的普遍适用策略中特别有趣的原因。提出的项目方法旨在通过在铣削工具的次要功能表面上应用定义的结构来潮湿或破坏再生聊天振动。根据工作假设，这些结构应例如吸收横向力，指导切割运动或引起摩擦效应，从而抵消动态偏转。使用实验研究，可以证明定义功能表面结构的过程稳定的潜力。 HSS铣削工具的次要尖端边缘的侧面是用圆形结构制成的，用于铣削操作，并对实验确定的稳定性极限进行了评估。可以实现高速速度稳定性的主轴速度稳定性和高达60％的生产率的提高。该项目倡议的目的是对结构设计与过程动态之间的因果关系进行基础研究。为此，将开发一个模拟实验钻机，从而降低了芯片形成过程的复杂性，从铣削到正交切割。动态偏转由振荡工具系统的定义激发表示。在基本研究的范围内，将测量和分析各种结构特征对芯片形成过程的影响。此外，选定的结构变体将转移到旋转对称的铣削工具中，并随后对其在铣削操作中的过程稳定潜力进行应用和评估。