圆柱齿轮锥形多刃刮齿刀具高效展成成形机理研究

For further improvement of power skiving tool life ande generating mechanism in the manufacturing of cylindrical gears, a productive generating method is proposed based on the skiving cutter with tapered multiple blades. This project aims to increase the tool life and the processing efficiency by breaking through the limitation of the existing generating theory of single blade tool. Three scientific problems are researched, including the modeling method of multiple blade tool cutting, the efficient generating process and the tool wear. Firstly, the mapping of movement between the machined gear tooth and the tool enveloped surface are obtained by establishing mathematical model of spatial envelope forming and interrupted cutting for the tapered multi-blade tool, subsequently the dynamic cutting force of the tool is solved. Then, investigating the mechanism of cutting force, cutting process, cutting heat and chip deformation by analyzing the chip separation criterion and the tool-chip interface tribological behavior with a multi-blade shear. Lastly, the influence of chip geometry on tool wear in the process of multiple blades cutting is studied using the experiment on a gear skiving machine. This project lays a theoretical foundation for the productive generating mechanism of cylindrical gears and the development of novelty tapered skiving cutter. Moreover, it is of important scientific significance and engineering application prospects.

针对圆柱齿轮强力刮齿技术中单刃型刀具寿命短、高效展成成形机理欠缺的问题，本项目提出基于新型锥形多刃刀具的高效展成成形方法，旨在突破现有单刃型刮齿刀具展成成形理论的局限，达到提高刮齿刀具寿命和加工效率的目的。项目围绕多刃刀具包络成形建模、高效展成成形过程、刀具磨损规律三个科学问题进行研究。通过建立锥形多刃刀具断续切削空间包络成形模型，探索被加工齿面和刀具扫掠面之间的映射和运动问题，并求解刀具的动态切削力；应用多刃剪切条件下的切屑分离准则和刀-屑界面摩擦学行为表征技术，从理论和实验两方面揭示多刃刀具展成过程中切削力、切削工艺、切削热与切屑变形的作用机理；采用物理样机开展刀具寿命实验，研究多刃成形过程切屑几何特征对刀具磨损的影响规律，最终掌握多刃刮齿刀具的高效展成成形机理。本项目可为解决圆柱齿轮多刃高效展成成形机理性难题和研制新型锥形多刃刮齿刀具奠定理论基础，具有重要的科学意义和工程应用价值。

强力刮齿是一种高效高精、绿色干切的齿轮加工工艺，能够满足汽车变速箱、精密减速器等领域对复杂齿轮结构型式的加工需求。然而，该工艺在实际应用中存在着刀具使用寿命短的难题，制约了其发展和应用。本项目突破现有单刃型刮齿刀具展成成形理论的局限，提出一种具有均载延寿结构的锥形多刃刮齿刀具及其设计方法，揭示了圆柱齿轮锥形多刃刮齿刀具的高效成形机理。主要研究内容包括：（1）建立了锥形多刃刀具断续切削空间包络成形模型，阐明了齿面和刀具扫掠面之间的运动关系，分析了单刃型和多刃型刮齿刀具的切削成形机理；（2）提出了具有均载延寿结构的多刃刮齿刀具及其设计方法，研究了基于未变形切屑几何特征的多刃刮齿刀具切削力计算方法，揭示了多刃刀具切削力与切屑几何特征之间的关联规律；（3）研究了刮齿关键工艺参数对齿面误差的影响关系，得到了刀具设计参数、切削工艺参数、刮齿加工敏感误差对齿面精度的作用规律，基于此方法，实现了考虑齿面精度特性的圆柱齿轮包络铣削加工；（4）开展了锥形多刃刮齿刀具切削加工实验，检验了切削力计算方法和切屑成形演变模型，并分析影响刀具磨损的关键工艺参数，最终掌握了多刃刮齿刀具的高效展成成形机理与刀具设计方法。基于上述成形理论和刀具设计方法的研究，研制了锥形多刃刮齿刀具，开发了强力刮齿刀具设计软件，目前已在恒锋工具股份有限公司实现了推广应用。项目研究成果丰富和完善了圆柱齿轮的高效展成切削理论，为研制新型多刃刮齿刀具和提升刮齿刀具切削效能奠定了理论基础，预期在小模数精密齿轮加工工艺中具有较好的应用前景。