【作者】 席庆坡；

【导师】 刘华；

【作者基本信息】 机械科学研究院 ， 机械设计及理论， 2003， 硕士

【摘要】 目前，齿轮的主要加工方式仍然是切削加工或者先热锻，后机加工，这导致生产成本高昂，效率低下。与传统成形方法加工的齿轮相比，精锻齿轮具有无飞边、无后续机加工等优点，从而节省原材料和能源耗费，降低成本和提高生产率，具有显著的经济效益。近年来，齿轮精锻技术的研究越来越活跃。作为国家十五“863”计划，本文针对直齿圆柱齿轮精锻工艺相关技术进行了研究。 本文采用数值模拟和试验研究相结合的手段进行研究。利用VBA完成了渐开线齿轮几何造型和模型建立，解决了在AutoCAD2000下不能绘制渐开线齿形的问题；介绍了刚塑性有限元法基本原理，并探讨了迭代收敛、网格重分等几个关键问题；对浮动凹模和中空分流等工艺进行了数值模拟和试验研究，分析了影响径向充填的关键因素，尤其是摩擦系数对成形的影响，提出了改善充填状况的方法，提出了均衡成形思想。 针对DEFORM-3D软件后处理功能的不足，研究了数值模拟后处理方法，得到了工件的边界曲线，为进一步的高精度模拟分析提供了手段；比较了当前精锻齿形修形方法，用数值模拟和试验相结合的手段，分析了精锻过程中各环节对齿形精度的影响，用弹性有限元法模拟了模具的弹性受力变形和齿轮出模弹性回复对齿形精度的影响，得到了模具齿形的变化规律，并提出了全新的修形方案；最后，采用本文的工艺手段和精度控制措施，进行了一系列齿轮精锻试验，并进行了小批量的生 摘要产。 本文最后对成形齿轮进行了精确测量，结果显示，成形齿轮精度达到国家8级水平。本文的研究工作为最终863科研任务的完成奠定了基础。更多还原

【Abstract】 Spur gears are mainly manufactured by metal cutting or by a combination of conventional hot forging with machining, which results in high production cost and much manufacturing time. Precision forging of gears has a lot of advantages compared to conventional gear shaping, because it allows the manufacture of gear parts without flash and consequently without the need for subsequent machining operations. Therefore, the implementation of such a technology is capable of providing important economic benefits in terms of raw material and energy savings, and also achieve considerable cost saving due to higher productivity. In recent years, the development of precision gear forging process has been an area of increasing activity. As one of the 863 Programs, this thesis aims at a detailed investigation of cold precision forging of spur gearsThe study in this thesis were performed by the combination with numerical simulations and experiments. Firstly, the CAGB of spur gears using VBA was realized, which solved the problem of tooth profile drawing in AutoCAD2000. Then, the rigid-plastic FEM was introduced and several important problems in simulation such as convergency and remeshing were discussed. And plenty of simulations and experiments have been carried out to analyze thevarious processes of gear forging, and several factors such as the friction factor, which had great influence on the radial flow of the material, have also been investigated. As a result, the equilibrium filling concept has been put forward.To make up for the deficiency of the graphical display in post-process of DEFORM, a new method that can automatically obtain the profile of the object has been achieved, which made it possible to catch the slightly deformation of the die. Additionally, lots of simulations and experiments were done to analyze the different factors influencing the gear tooth accuracy, such as the elastic expansion of die and the spring-back of the forged gears. Consequently the deformation mechanism of the closed die has been obtained and a new method of tooth profile modification was put forward. At last, with the improved forming process and accuracy control operation in this thesis, series of experiments of precision gear forging have been implemented.The result of the measure about the forged gear is satisfied.The accuracy has reached class 8^th according to GB10095, and the effort in this thesis has provided a basis for the accomplishment of the 863 Program.更多还原