Research On Nc Turning Parameter Optimization Method For Low Energy Consumption And High Surface Quality

Turning is an important machining process in machinery manufacturing.NC turning parameters,including cutting speed,feed rate and cutting depth,must be determined and selected during cutting operation.In order to optimize the turning parameters reasonably,considering machining energy consumption,machining efficiency and surface quality,the optimization method of turning parameters for low energy consumption and high surface quality was proposed.The choice of turning parameters is directly related to the work condition,affecting the power utilization of the machine tool.In order to measure the power of NC machine tool,WB9128-1 three-phase power sensor was adopted to establish the power monitoring system.Based on the power monitoring system,the turning experiment of 45#steel on CAK3665ni was carried out.Results of orthogonal analysis shows that the cutting speed,feed speed and cutting depth have significant influence on the power of NC lathe.Although increasing the turning parameters can increase the power consumption rate,due to the increasing of material removal rate and the decreasing of processing time,the total power consumption was reduced by increasing the cutting parameters.To analysis the power consumption rate of the NC lathe quantitatively,the factors related to energy flow were analyzed and mathematical models including the constant power,the spindle power,the feed power and the load power was presented which is suitable for predict the power of NC lathe.Turning parameters have a huge impact in the microscopic appearance,thereby affect the surface quality.The surface of work-piece was measured by the Mitutoyo SV-3100 surface roughness tester.In order to evaluate the different surface quality reasonably,the formula of product quality loss function in Taguchi method was used to evaluate the surface quality.The experimental results show that increasing of cutting speed can improve the surface quality,and increasing of the feed rate can reduce the surface quality.Considering the interaction of turning factors,the mathematical model of surface roughness was built.Considering the energy consumption and surface quality of work-piece,a mathematic model was established based on the goal of low-SEC and low-average roughness.NSGA-? multi-objective genetic algorithm was used to optimize the turning parameters.The optimization results show that the energy consumption will increase rapidly when the feed rate is less than 0.1mm/r,and the surface quality will deteriorate rapidly when the cutting depth is bigger than 0.4mm.To guide the choice of turning parameters,the optimization results were evaluated by linear weighted sum method.The optimized cutting parameters is:cutting speed 250m/min,feed rate 0.09mm/r,turning depth 0.45mm.After optimization,the SEC decreased from 9.91J/mm3 to 7.33J/mm3,the average roughness decreased from 1.19?m to 0.88?m.Based on NSGA-II,the optimization method of turning parameters for low energy consumption and high surface quality can optimize the NC turning parameters reasonable and effectively,and the method can provide reference for the choice of cutting scheme.