基于PLC的挤出机进料段内螺纹加工控制系统研究

Control system of inputting part screw of plastic extruder internal screw based on PLC

针对普通车床在塑料挤出机进料段内螺纹加工时存在效率低和内螺纹螺距超过500 mm时无法自行加工的问题,将采用触摸屏、PLC和其位置单元设计开放式控制系统的技术应用于研制高效数控专用铣床中。开展了内螺纹螺旋线理论方程和现有加工过程的分析,建立了专用铣床在内螺纹加工过程中各个轴之间的运动关系,提出了"采用威纶触摸屏MT8000和松下FP2可编程逻辑控制器及其插补型位置单元,设计内螺纹加工的专用铣床及其控制系统"的方法;在理论上对内螺纹加工铣床的可行性和加工效率进行了评价,并进行了控制系统的试验和生产实践。研究结果表明,所研制的数控铣床在进料段内螺纹加工时的效率提高了25%以上,达到了预期设计要求,同时加工系统还具备"操作界面简单、容易上岗"等特点。

Aiming at the problems of the general machine tool＇s low efficiency to manufacture inputting part screw of plastic extruder and the screw cannot be proper motion processed when screw pitch over 500 mm,the open system technology developed by touch screen,PLC and its location unit were applied to develop efficient CNC special purpose milling machine.After the analysis of the theoretical equation of internal thread and existing internal screw machining process,the relationship between each axis to internal screw processing was established.A method was presented to process internal screw and its control system had been proposed,by taking advantage of touch screen MT8000 from WEINWIEW company,programmable logic controller FP2 from Panasonic company and its interpolation type location unit.During the research,the feasibility and efficiency of this special machine were evaluated in theory and the control system was tested.The results indicate that the efficiency of internal screw processing is increased by more than 25％,satisfying expecting demand.Also,this machine designs a friendly operating interface,which will be easy learned by new workers.