微量润滑系统参数对切削环境空气质量的影响

Investigation on the Influence of System Parameters on Ambient Air Quality in Minimum Quantity Lubrication Milling Process

微量润滑(Minimum quantity lubrication,MQL)切削是现代机加工领域一项先进的准干式切削技术,但微量润滑切削过程中产生的切削油雾仍会影响切削现场的环境空气质量,危害切削场所人员的健康。基于重量分析法,对微量润滑条件下的切削现场油雾浓度进行了测量与分析,揭示了润滑油用量、供气压力、喷射靶距、射流温度以及润滑油特性等微量润滑系统参数对切削现场油雾浓度PM10与PM2.5的影响规律。研究结果表明,润滑油用量是影响切削现场油雾浓度的最主要因素,随着润滑油用量的增加,切削现场油雾浓度显著增大,应控制在15 mL/h以内;在射流温度较低的条件下,空气中悬浮的水汽会发生凝结与黏附现象,从而造成低温微量润滑条件下的油雾浓度检测结果较室温条件下明显增大,但低温微量润滑条件下切削现场油雾浓度会随着射流温度的降低而相对降低。

Minimum quantity lubrication （MQL） has been accepted as a successful semi-dry application because of its satisfactory performance in practical machining operations.However,the oil mist generated from MQL machining process has a direct impact on the ambient air quality,and then does harm to those who permanently work in this environment.Using the weighing method,the oil mist concentration in machining workshop is measured and analyzed,and the influence of MQL system parameters such as oil flow rate,air pressure,spray distance to target,jet temperature and lubricant property on the oil mist concentration PM10 and PM2.5 in the machining workshop are investigated.The results show that oil flow rate is the most important factor which affects the oil mist concentration in the machining workshop.With the increase of oil flow rate,the oil mist concentration increases significantly.The oil flow rate should be limited to less than 15 mL/h.The water vapor in the air is easy to condense and adhere to the fine particles at low jet temperatures,which results in that the measurement results of oil mist concentration are higher than those at room temperatures.But the oil mist concentration will decrease as the jet temperature decreases during the cryogenic MQL milling process.