Investigation of the effects of cooling in hard turning operations
Investigation of the effects of cooling in hard turning operations
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DOI：
10.1007/s00170-005-0128-4
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发表时间：
2006-10
期刊：
影响因子：
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通讯作者：
A. Noorul Haq;T. Tamizharasan
中科院分区：
文献类型：
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作者：
A. Noorul Haq;T. Tamizharasan
作为克服切削液在加工中的局限性的一种手段，切削刀具的内冷却越来越受到重视。硬车削中切削区温度升高会导致切削区冷却液瞬间沸腾，造成热变形，从而降低刀具寿命和表面光洁度，因此在大多数硬车削操作中根本不使用冷却液。冷却液的缺乏也在一定程度上降低了刀具寿命和表面光洁度。作为一种替代的解决方案，直接在金属切削区的冷却剂，以提高刀具寿命和表面光洁度，热管冷却系统介绍了这项调查。通过参数化研究，分析了热管直径、热管长度、热管真空度和热管材料等参数对热管性能的影响。所有这些参数变化到三个水平。在该分析中，假设单点切削刀具在切削区域中受到静态加热，这验证了在车削操作中使用热管冷却的分析和可行性。利用田口实验设计法对热管参数进行了优化，并利用最佳参数值制作的热管进行了验证试验。验证试验的结果与以前的实验结果进行了比较。比较表明，在硬车削操作中使用热管可将温度场降低约5%，通过减少刀具磨损提高刀具寿命，并显著提高表面光洁度。此分析结果可应用于各种相关研究之热管最佳化设计与设置之控制参数之确定。有限元分析还表明，温度下降很大，在切削区和热流的工具时，热管被有效地删除。
As a means to overcome the limitations of cutting fluids in machining, more and more attention is being paid to the internal cooling of cutting tools. The elevated cutting zone temperature in hard turning causes the instant boiling of coolant in the cutting zone, which pulls down the tool life and surface finish, by making thermal distortions and hence in most of the hard turning operations, the coolant is not used at all. The absence of coolant also reduces the tool life and surface finish to some extent. As an alternative solution to the direct application of coolant in the metal cutting zone to improve tool life and surface finish, the heat pipe cooling system is introduced in this investigation. A parametric study is conducted to analyze the effects of different heat pipe parameters such as diameter of heat pipe, length of heat pipe, magnitude of vacuum in the heat pipe and material of heat pipe. All these parameters are varied to three levels. In this analysis, it is assumed that the single point cutting tool is subjected to static heating in the cutting zone which verifies the analysis and feasibility of using heat pipe cooling in turning operations. The heat pipe parameters are optimized by using Taguchi’s Design of Experiments and a confirmation test is conducted by employing the heat pipe fabricated with the best values of parameters. The results of the confirmation test are compared with the previous experimental results. The comparison shows that the use of a heat pipe in hard turning operations reduces the temperature field by about 5%, improves tool life by reducing tool wear and improves surface finish significantly. The result of this analysis is applicable to define controlling parameters of heat pipes for optimal design and set-up for various related studies. The finite element analysis also shows that the temperature drops greatly at the cutting zone and that the heat flow to the tool is effectively removed when a heat pipe is incorporated.