Research On Screw Deformation Prediction Model Based On Real-time Data Of Machine Tools

Z-axis screw exists a large amount of thermal deformation,thermal balance for a long time,running to maintain the thermal balance of the screw and other problems in the 3C product processing of high-speed drilling center.In this paper,the thermal deformation prediction model of the screw rod based on the real-time data of the machine is studied in order to compensate the thermal error of the machine without temperature sensor.High-speed drilling center is a small machine tool.The temperature sensor,which is installed for thermal deformation prediction on high-speed drilling center,will change the structure and increase the machine's production costs.The study found that the structure of the feed system determines the direction of its thermal deformation,the servo motor load current,feed speed,screw force determines the number of friction torque work,thus affecting the thermal deformation of the screw.A thermal deformation prediction model based on time is proposed for high-volume and repetitive processing.The model make CNC machine tool's manufacturing processes divided into heating process and cooling process and establish the heating model and cooling model.In the actual prediction,the models can be integrated according to the current working state to realize the thermal deformation prediction of the whole process.A thermal deformation prediction model based on screw energy consumption is proposed to adapt to the changing process.The model make screw's internal energy as study object,and analyze the friction heat of the screw nut and the convective heat dissipation of the air.The relationship between the thermal deformation of the screw is established by using the energy loss of the screw.Regression is to solve the model parameters.In this paper,the thermal error compensation module of no temperature sensor is developed in the numerical control system according to the screw thermal deformation prediction model and the compensation effect of the corresponding model parameters is verified.The results show that the thermal error compensation module based on time can reduce thermal error from 0.03 mm to 0.006 mm,and its compensation rate is 80%.The thermal error compensation module based on screw energy consumption can reduce thermal error from 0.051 mm to 0.004 mm,and its compensation rate is 92%.