Efficient Slitting Turn-milling Compound Machine Tool Precision Analysis And Process Optimization

In various types of weapons and equipment,three-dimensional complex precision microstructure parts are widely used.And for the high processing quality requirements,this part is difficult to process.In the stereotyped production of weapons and equipment,there appeared issues like the processing accuracy that can not meet the requirements,the low yield,the low productivity and high production costs.At present,various processing forms of decentralized processing are used in the processing of such structural parts,also multiple equipment and a group of operating workers are required.In small-sized complex parts,it's difficult to achieve the manufacturing of a number of directional holes,grooves,steps,surfaces and other geometric elements,because of the growth of the repeated positioning error caused by the multiple clamping process.Also there are other reasons that make it difficult to meet the requirements of precision parts,such as the staff and large operating area that the sequence processing equipments need,time-consuming,labor-intensive and high production costs.Therefore,in this paper,a processing method of three-dimensional micro-parts,high-efficient cutting complex processing technology,is put forward,considering efficiency,cost and precision.And a high-efficiency cutting-milling machine tool is designed and developed.Based on this,precision analysis of machine tools and process optimization research are carried out.The main research contents and conclusions are as follows:(1)Research on Overall Scheme of High Efficiency Slitting Turn-milling Machine Tool.Taking the lower slewing body parts as the research object,the processing needs and processing targets are analyzed.And the overall design of the slitting turn-milling machine tools is carried out,in order to improve the processing efficiency.And the structure of doubleturning spindle is adopted to realize the function of completing all the machining processes in one clamping.The design of high-frequency milling structure and micro-turret structure can achieve surface processing functions.The lathe module,control system was designed.Also,the high efficiency slitting turn-milling machine tools was developed,which provide equipment support for further efficient and high-precision machining technology and experimental research.(2)Research on Static Error of High Speed Slitting Turn-milling Machine Tool.The influence of static factors on the machining accuracy of parts is studied,also the static error of machine tools is studied.Based on the analysis and calculation of the static assembly error of the bed body to the spindle and the milling cutter,and the influence on the machining accuracy,the static accuracy test is carried out on other motion axes besides the Y axis.The axis parallelism,spindle runout and other important indicators that ensure the performance of the machine tools are tested.The static precision compensation is used in the machine based on the error size.The machining experiments can effectively reduce the static error on the part machining accuracy.(3)Study on Dynamic Error of High Speed Slitting Turn-milling Machine.The study of dynamic error is carried out,in order to reveal the influence of dynamic factors on machining accuracy of parts.Based on the theoretical model of dynamic characteristics of high-speed slitting machine tool,the modal of the machine tool is simulated by finite element analysis and the modal experiments are carried out to get the first six natural frequencies and mode shapes.The results show that the simulation is in good agreement with the experiment,and the correctness of the simulation model is verified.The research on the influence of machine idle condition on the machining stable zone is carried out.The steady lobe map of the machine tool is obtained through the experiment of hammering,and the stable part of machining of the part is obtained under the lobe pattern turn-milling envelope curves.Through the selection of machining cutting parameters in the stable area,the influence of dynamic error on the machining accuracy of the part can be reduced.(4)Process Experiment and Optimization of High Efficiency Slitting Turn-milling Machine Tool.Aiming at the key difficult structural features and the parts that are difficult to guarantee the precision of the lower slewing body parts,the basic experimental scheme design and sample processing experimental research are carried out.An experimental study on the turnmilling process of the roughness and the cylindricity is carried out,and it takes shaft parts as the research object.An experimental study on the groove width milling process is carried out,and it takes the slotted part as the research object.The process test is carried out with the lower slewing body parts and hole thin-walled processing as the object.The process is designed based on the thin-walled processing simulation analysis.A total of 270 samples of27 groups are machined on the large plane,small axis and thin wall of the lower slewing body,and analyze for error.The experimental results show that the selected processing parameters can meet the processing requirements.