开式热沉内冷刀具的设计及其导热性能分析

车削加工温度对工件的表面加工质量和刀具的使用寿命具有重要影响. 设计了一种开式热沉内冷刀具，计算了在实际加工工艺参数下刀具受到的切削力和前刀面上的热流密度，分析了刀具的结构强度；建立了刀具热-流-固耦合温度场模型，探讨了热稳态条件下刀具的温度场分布，以及刀片冷却液流道内热沉数量对刀具导热性能的影响规律，比较了在相同热源条件下开式热沉内冷刀具与其他内冷刀具的导热性能. 结果表明:对于刀片材料为硬质合金YT5的刀具，在热流密度为10 W/mm2的条件下，内置6个热沉的设计方案可获得最佳冷却效果，刀具的最高切削温度控制为187.1 ℃；与其他内冷刀具相比，开式热沉内冷刀具的最高切削温度降低了12.1 ℃. 

Design and Thermal Performance Analysis of an Open Internal Cold Cutting Tool with Heat Sinks

The turning temperature has an important influence on the surface quality of workpiece and the service life of cutting tool. An open-type heat sink internal cooling tool was proposed in this study, and its structural strength was analyzed firstly by calculating the cutting force and heat flux density on the rake face under the practical machining process parameters. Based on the established thermal-flow-solid coupling temperature field model, the temperature field distribution of the tool under the heat steady-state condition was then obtained. Furthermore, the influence of the number of heatsink in the blade coolant flow channel on the thermal conductivity of the tool was studied.Comparisons of the thermal conductivity between the open-type internal cooling tool with heat sinks and other internal cooling tools under the same heat source conditions were conducted. The results show that with the blade material of cemented carbide YT5, the tool had the best cooling effect (maximum cutting temperature was 187.1 ℃), when 6 heat sinks were applied under the heat flow density 10 W/mm2. The maximum cutting temperature of the open-type internal cooling tool with 6 heat sinks was reduced by 12.1 ℃ by comparing to that of other internal cooling tools.