The Study Of Thermal Deformation Error With High-speed Whirlwind Hard Milling Ball Screw

Precision ball screw is the key feature of the CNC machine tools, its transmission and positioning accuracy directly determines the accuracy of CNC machine tools. To improve ball screw drive and positioning accuracy, it is necessary to improve the manufacturing precision of the screw thread. The traditional ball screw threaded processing depends on the final fine grinding process to ensure accuracy, grinding will produce a lot of dust and grinding fluid, pollution of the environment. And fine grinding generally need2-3times to complete, the efficiency is very low. In contrast, the whirlwind hard milling screw thread can be a complete cutting, the machining efficiency is5-8times as the grinding, and the use of compressed cold air cooling, to avoid the pollution of dust and grinding fluid. So it’s an efficient and green thread processing methods.In the whirlwind hard milling ball screw process, the effective control of the thermal deformation error is the key factor to improve the accuracy of screw helix and reduce the thread pitch error. It’s very necessary to solution this technically problem for the domestiec enterprises introduce foreign advanced equipment. Study the distribution of temperature field and thermal deformation law on ball screw in processing is the premise to solve the technical problem.This paper uses the virtual simulation technology combined with experimental verification to obtain the temperature distribution and thermal deformation law on the ball screw in the process of whirlwind hard milling. The study mainly includes the following aspects:(1) Through consulting the domestic and foreig related literature, understand the development trends and existing technical problems of the whirlwind hard milling technology. Studied the method of finite element thermal analysis in the past and the existing advanced technology abroad.(2) Through the analysis of the basic principle of whirlwind hard milling technology, using the special cutting simulation software DEF0RM-3D to create the correct milling model, and optimized the milling process parameters by aiming with the processing efficiency and quality. And get the milling heat in proportion to the allocation of the tool, workpiece and chip.(3) Through loading moveing heat source in finite element analysis software ANSYS, studied the temperature distribution and thermal elongation law on ball screw in the whirlwind hard milling process. Established the simulation parameters model of temperature field and thermal elongation in the whirlwind milling process, can be obtained the temperature field distribution and thermal deformation law of ball screw before the processing, provide the basis for the error compensation of screw pitch in the actual processing.(4) Measured the temperature of ball screw at different times by infrared remote thermometer in the processing, and record the measured date; Measured the total elongation amount of the screw by installation floating displacement sensor at the end of the screw in the processing, and record the measured date.(5) Throgh the comparison of the experiment data and simulation results to verify the correctness of the simulation parametric model.