断续磨削表面烧伤机理与在线监测方法研究

目的 研究断续磨削烧伤机理和声发射在线监测方法,避免产品磨削加工烧伤现象.方法 基于平面磨削温度场理论和镜像热源方法,建立一种断续磨削工件边缘的温度场模型,基于该模型可对断续磨削烧伤机理进行研究.为验证上述模型的有效性,通过正交实验设计不同断续磨削工况实验,利用红外热成像仪和声发射信号对断续磨削区温度进行在线监测,使用酸洗法和巴克豪森噪声检测仪对磨削后工件表面进行烧伤检测验证,通过对声发射信号的小波包能量求解,建立其与磨削区温度之间的关系.结果 该模型可有效反映断续磨削时工件边缘处磨削区温度场分布情况.计算结果表明,断续磨削工件断口边缘比其他位置磨削区温度更高,且更容易引起烧伤.实验表明,声发射信号的小波包变换总能量与磨削区呈一定相关性,基于声发射信号可对断续磨削烧伤实施在线监测.结论 实验结果证明了该模型对断续磨削烧伤机理分析的有效性,以及利用声发射信号对断续磨削烧伤在线监测的可行性.最后针对某一转向螺母产品实际断续磨削加工烧伤进行在线监测应用,实践结果表明,该方法比传统酸洗烧伤检测更加高效环保,对实现磨削加工烧伤检测自动化和智能化具有重要意义.

Research on Burn Mechanism of Intermittent Grinding Surface and Online Monitoring Method

Study the mechanism of intermittent grinding burn and the on-line monitoring method of acoustic emission to avoid the phenomenon of product grinding burn. Based on the surface grinding temperature field theory and the mirror heat source method, a temperature field model of the intermittent grinding workpiece edge is established. Based on this model, the intermittent grinding burn mechanism can be studied. In order to verify the effectiveness of the above model, the orthogonal Experiments were designed for different intermittent grinding conditions. Infrared thermal imaging cameras and acoustic emission signals were used to monitor the temperature of the intermittent grinding area on-line, and the pickling method and Barkhausen noise detector were used to burn the surface of the workpiece after grinding. Inspection and verification, by solving the wavelet packet energy of the acoustic emission signal to establish the relationship with the temperature of the grinding zone. This model can effectively reflect the temperature field distribution of the grinding zone at the edge of the workpiece during intermittent grinding. The calculation results show that the edge of the fractured grinding workpiece has a higher temperature and is more likely to cause burns than the grinding zone at other positions; the experiment shows that acoustic emission The total energy of the wavelet packet transform of the signal has a certain correlation with the grinding area. Based on the acoustic emission signal, the intermittent grinding burn can be monitored online. The experimental results prove the effectiveness of the model for analyzing the intermittent grinding burn mechanism and the feasibility of using acoustic emission signals to monitor the intermittent grinding burn online; finally, the actual intermittent grinding burn burn of a certain steering nut product is carried out online Monitoring application, practical results show that this method is more efficient and environmentally friendly than traditional pickling burn detection, and it is of great significance to realize the automation and intelligence of grinding processing burn detection.