【作者】 邓陶勇；

【导师】 刘全坤；

【作者基本信息】 合肥工业大学 ， 材料加工工程， 2007， 硕士

【摘要】 冷精锻齿轮工艺中，模具的弹性变形和锻件的弹性回复行为是不可避免的，并且二者对精锻件的精度产生很大影响。本文以冷精锻工艺中齿形凹模的弹性变形及齿件的弹性回复规律为研究对象，精确预测齿轮产品的尺寸偏差，以轮齿表面的偏差分布为依据对凹模型腔进行补偿修正，提高冷锻齿件的精度，指导实际生产。本文以三维有限元数值模拟作为研究手段，采用同时计算齿件弹塑性大变形和模具弹性变形的模拟方案。首先研究了凹模外内径比、凹模高度、摩擦系数等工艺参数对齿形模腔弹性变形、齿件弹性回复的影响情况。其次对比研究了组合凹模有限元模型建立的准确性与合理性。然后对齿形组合凹模进行迭代优化设计。采用最优设计的组合凹模，研究冷精锻工艺中模具弹性变形和齿轮的弹性回复；依据偏差分析的结果，提出采用反扩张修正系数法和黄金分割法相结合的方案对齿形模腔进行迭代修正，旨在以非渐开线齿腔得到渐开线齿轮产品，并且满足精度要求。研究表明，模具在齿轮冷锻工艺中发生径向弹性扩张。在齿形、齿高及齿形曲线的法向上弹性变形量均呈有规律的变化；出模后，齿轮沿径向发生弹性回复，回复量对齿轮精度产生影响。两者在渐开线齿形上的变化趋势导致齿件在法向的偏移值呈不均匀分布，这使得传统修形方法存在明显不足。本文提出的反扩张修正系数法可以精确修正齿形模腔，以得到高精度的齿轮产品。更多还原

【Abstract】 Die elastic deformation and component spring-back is unavoidable in cold net-shape forging technology of spur gear, and they play an important role in dimensional accuracy. In this paper, die deflection and component spring-back is regarded as the research object. Component dimensional error is pre-estimated exactly, then die compensation is carried out according to error distribution in gear tooth surface, and accuracy of gear forging is increased at last.Adopting numerical simulation, elastic-plastic deformation of gear forging and die elastic deformation is calculated at the meantime. Firstly, processing parameters, such as ratio of external diameter and internal diameter height of female die coefficient of friction are studied, and their influence on die deflection and component elastic recovery is analysed. Secondly, castellated assembling die is designed by iteration optimum method. Thirdly, optimum die is employed, and the rule of die elastic deformation and component elastic recovery is researched. Last, according to error analysis results, negative expensation compensation factor is brought forward, and female die is compensated by golden section method, to gain involute gear product, whose accuracy is satisfied.In cold forging of spur gear, die surface is expanded radially. Numerical value of die deflection is distributted variably in profile of tooth height of tooth normal direction of curve. Gear unloaded, component elastic recovery is generated in radial direction, and its value affects component accuracy. Die deflction and component spring-back makes normal deviant of various points in involute vary. The method brought forward in this paper can compensate the die of cold forging accurately and obtain gear product, which is provided with high degree of accuracy.更多还原