Abstract: In order to solve the problems that the large-length-diameter ratios deep-hole machining had difficulty to chip removal, the negative pressure jet model was established on the basis of analyzing the mechanism of DF（double feeder） system‘s negative pressure chip removal. A wedge structure at the jet nozzle was designed to reduce the energy loss in the areas by the method of filling in the partial areass of the front and rear separation zones. Through theoretical calculation and Fluent simulation optimization experiments, the results show that the wedge size is the best when the length is L1 = 75 mm and the width is L2 = 1 mm, which enhances the cutting fluid flow rates by about 10.07%, increases the turbulent kinetic energy by about 11.39%, and reduces the negative pressure values by about 79.26%. The wedge structure enhances the ability of negative pressure chip removal, and reduces the front and rear separation area energy loss maximally.

Key words: negative pressure chip removal, front and rear separation area, wedge structure, simulation optimization

摘要： 为解决超大长径比深孔加工排屑困难问题,在分析DF系统负压排屑作用机理的基础上,建立负压射流模型,通过采用填充部分前/后分离区所占区域的方法,设计了一种位于射流喷嘴处的楔形结构,以减少前/后分离区的能量损耗。理论计算及Fluent仿真优化实验结果表明,该楔形尺寸在长度L1=75 mm、宽度L2=1 mm时效果最好,切削液流速增大约10.07%,湍流动能增大约11.39%,负压区压力值减小约79.26%,该楔形结构提高了负压排屑能力,最大程度地减少了前/后分离区的能量损耗。

关键词: 负压排屑, 前/后分离区, 楔形结构, 仿真优化