精密卧式车床热误差溯源、建模与实时补偿

Tracing,modeling,and real-time compensation of thermal error in precision horizontal lathe

精密卧式车床的关键部件会在内外热源的综合影响下发生热变形,进而严重影响加工精度。数据驱动的热误差建模方法为解决此问题提供了有效手段,而厘清车床的关键热误差元素及其传导机理可进一步提高车床热误差的建模效率、精度和鲁棒性。文章针对车床X轴丝杠摩擦热、主轴发热、Z轴鞍座发热以及液压刀塔和拖板发热4个关键热误差元素开展了溯源测试,并根据溯源结果建立了热误差模型并开发了热误差实时补偿系统。车削验证实验结果表明,补偿后车床的加工误差在反复的加工和冷机过程中均稳定降低了75%以上,文章所提的热误差溯源和补偿方法有效提高了车床的加工精度和稳定性。

The main components of precision horizontal lathes are subject to thermal deformation arising from the combined influence of internal and external heat sources,which may significantly affect the machining accuracy.Data-driven thermal error modeling methods provide an effective means of addressing this issue,while clarifying the key thermal error elements and their conduction mechanisms can further enhance the modeling efficiency,accuracy and robustness of the lathe thermal error.This paper focuses on the source tracing test of four key thermal error elements of the lathe:X-axis screw frictional heat,spindle heat,Z-axis saddle heat,and heat of hydraulic turret and drag plate.Based on the tracing analysis results,a thermal error model was established,and a real-time compensation system was developed.The turning validation experiment results show that the machining error of the lathe after compensation was stably reduced by over 75%during repeated machining and cooling processes,which revealed that the proposed method effectively improved the machining accuracy and stability of the lathe.