Research On Optimization Of Cutting Parameters In Number Control Lathe

There are many reasons that affect the surface quality, the surface roughness and the cutting efficiency. Designing machines and machining machine parts, we should take into account not only the existence of various errors and their effect on the surface quality of maching parts but also the improvement of production efficiency. This paper analyzed the factors that affect the precision of NC machining and the factors influencing the machining precision. The numerical control lathe provided by Yunnan Machine Tool Plant and NC machining simulation software provided by Beijing Fick Company are used to analyse the machining precision of numerical control lathe and the optimization of cutting parameters.The research results show as follow:Through the experiment, the optimal range of rough spindle speed is 580r/min～620r/ min, which was different from the range of 550r/min～700r/min; Experiments show that when the roughness of the spindle was above 650r/min, the value of the dimensional accuracy or the value of the surface roughness was becoming worse; The machining time did not change with the spindle speed.The optimal range of spindle speed is 1180r/min～1240r/min, which is smaller than the range of 1000r/min-1500r/min.;Test results show that when the car reached 1400r/min, the dimensional accuracy decreased significantly and the surface roughness values were becoming larger;The change in the spindle speed does not have any effect on the machining time.The dimension is most precise when the best F-value of roughing speed is 140mm/min～160mm/min.The change of surface roughness is not obvious with the roughing speed, but the surface roughness value is relatively low when the roughing speed F was between the 110mm/min and 130mm/min; The cutting time decreased with the increase of cutting speed, and the machining efficiency was obviously improved. Therefore, in the processing, if the value of the surface roughness was not in high standard, the cutting speed could be set up when the F is between the 110mm/min and 130mm/min;If the surface roughness was not demanding, the cutting speed could be set up when the F is betwween 140mm/min and 160mm/min. The test showed that when the best F-value of the finish turning was between 90mm/min and 110mm/min, the dimension precision was the highest; when the F-value of the rough turning was between 90mm/min and 110mm/min, the value of surface roughness was the lowest;The cutting time decreased with the increase of cutting speed, and the processing efficiency was improved significantly.The test showed that when the back cutting depth of the rough turning was between 2mm and 2.5mm, the dimension precision was the highest; When the amout was between 2mm and 2.5mm, the value of surface roughness was the lowest; With the increase of the back cutting depth, the processing efficiency was improved significantly; Thus, the obtained-knife amout of the rough car shoud be between 2mm and 2.5mm.