【作者】 宋燕莎；

【导师】 李辉平；

【作者基本信息】 山东大学 ， 材料加工工程， 2013， 硕士

【摘要】 感应加热具有加热速度快、物料内部发热效率高、加热均匀,且具有产品质量好、几乎无污染、易于实现生产自动化等一系列优点,因此近年来得到了迅速发展。采用感应淬火处理滚珠丝杠能够较理想地解决表面和心部性能要求不一致的矛盾：既能改善表面强度、硬度和耐磨性,又能保持心部的塑性和韧性,从而提高其承受一定冲击负荷、抵抗磨损和疲劳的能力。利用计算机数值模拟方法来描述感应加热过程可以提前预测工件的温度场分布情况,找到获得确定淬硬层深度的加热工艺,进而修改相关参数优化其工艺性能。所以对丝杠的感应淬火进行有限元模拟具有现实意义。本文针对感应加热过程中工件温度难以测量的问题,应用电磁学和传热学基本理论,建立了滚珠丝杠坯料电磁场和温度场分布的数学模型,详细介绍了ANSYS感应加热模拟步骤,针对丝杠在静止线圈内感应加热过程及结果进行分析,得到相应结论。本文介绍了辐射、电流密度、电流频率等因素对滚珠丝杠感应加热过程的影响。利用ANSYS软件进行多次模拟总结得知：温度越高,辐射效果越明显；电流密度大小影响最终加热温度,电流密度值足够大,使得材料感应加热过程中温度能达到二次相变温度,之后材料温升曲线会有不同趋势；电流频率影响材料的透入深度,进而影响材料感应淬火后表面与中心的温差值。高频率能在极短时间内迅速提高材料表面温度,同时提高热效率。基于模拟线圈移动时所采取的随时间变化电流密度单元变化思路,研究滚珠丝杠在移动单线圈内感应加热的一般规律,由模拟结果得到相应结论,发现存在丝杠外表面和滚道温差过大的问题,改用移动双线圈进行感应加热,结果能够得到较好的改善。本文所得结论为合理选择加热参数提供参考依据,为揭示滚珠丝杠感应加热过程的规律、优化工艺参数提供理论依据。更多还原

【Abstract】 Induction heating is fast, efficient and well-proportioned, and it possesses many advantages such as high-grade production, no pollution, good controllability and easy to achieve automatic, so it developed very fast in the recent years. The induction quenching process of ball screw can perfectly resolve the contradiction about performance requirements inconsistent between the surface and center, Not only can improve the strength, hardness and wear resistance of surface, and can keep the plasticity and toughness of the center, so as to improve the ability of bearing load impact, abrasion resistance and fatigue resistance. The computer numerical simulation method of describing the induction heating process can predict the temperature field distribution of the work piece, find the access to determine the hardened layer depth of heating process, and then modify the relevant parameters to optimize processing property. Therefore, the finite element modeling of induction quenching has a realistic significance.Aiming at the difficulty in measuring for induction heating, based on the electromagnetic theory and thermal theory, it constructed the mathematic analysis models of the ball screw performing electromagnetic field, temperature field, the induction heating simulation steps of ANSYS were introduced, According to the analysis and the results of induction heating process, we got the corresponding conclusion.The influences of radiation, current density, current frequency to the induction heating process were introduced. Finally, concluding that:The higher the temperature is, the more obvious effects of radiation; the current density values affects the ultimate level of heating temperature, if the current density values is large enough, the temperature of induction heating can reach Secondary phase transition temperature, After that the temperature rise curve will have a different trend; The current frequency affects the penetration depth of material, which will affects the temperature difference between the surface and the center after induction hardening. High frequency can improve the surface temperature rapidly in a very short period of time, while improving the thermal efficiency.Along with the time changing, the current density loading unit changes, General rules of ball screw induction heating in mobile single-turn coil were researched. Some conclusions are drawn from the simulation results; there is a problem that the temperature difference of outer surface and raceway of screw is too large. With double coil for induction heating, the result is better.The conclusion of this paper provides reference basis for reasonable choice of heating parameters, and provides a theoretical basis for the optimization of process parameters.更多还原