深孔加工负压排屑装置收缩环状结构优化设计

Deep-hole Processing Optimized Design and Simulation of Contraction Ring Structure Negative Pressure Chip Removal Device

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。采用一种位于射流喷嘴前部收缩环状切削液通道,取代前分离区所占体积的方法,降低该区域造成的能量损耗。通过理论计算以及Fluent仿真优化试验,证明该收缩环状通道设计的椭圆尺寸在长半轴x=20mm、短半轴长y=2mm时效果最好,切削液流速提高约9%,湍流动能提高约6. 75%,负压区压力值降低约70. 43%,最大程度地降低了前分离区域能量损耗,增强了负压排屑能力。

In order to solve the problem of difficult chip removing of the large-length-diameter ratios in deep-hole machining,the negative pressure jet model is established on the basis of analyzing the mechanism of DF system＇s negative pressure chip removal. The use of contraction ring structure at the front of jet nozzle replacing the volume of the front separation zone reduces the energy loss caused by this area. The results show that the contraction ring structure size has the best effect in long half axis length x = 20mm and short half axis length y = 2mm. It can improve the cutting fluid flow rate about 9% ,enhance the turbulent kinetic energy about 6.75% and reduce the negative pressure value about 70.43%. The contraction ring structure reduce maximally the front separation area energy loss and enhance the ability of negative pressure chip removal.