Study on Improvement Technique of Process Controllability for Mirror Grinding by Stimulating Functionality

为了提高镜面磨削过程的可控性，提出了通过生成和评价工作表面状态来保持磨削过程中砂轮良好性能的有效方法。首先，基于刃口分布的变化，研究了修整工作表面的生成过程。结果表明，切割深度的临界值将修整方式分为脱落和微破碎两种。此外，还发现修整过程中的电火花是改善磨削表面粗糙度的一个重要过程。由于火花抑制了表面划痕的产生，表面粗糙度得到显著改善。然而，过多的火花会减少切屑的凹坑，使加载变得容易，从而使磨削表面粗糙度变差，尽管其具有较高的刃口密度。其次，超声激活冷却液对TH…的改善效果检测了更多的磨削表面粗糙度。观察到，用频率为MHz的超声波激活冷却液，可显著减少划痕的产生和深度。通过对砂轮的冷却液供应状况和工作表面状况的观察和评价，对其机理进行了探讨。结果发现，超声激活的冷却液能够克服砂轮周围的气流，从而很容易到达磨削点。这表明冷却液在磨削点稳定地起作用，以防止切屑的沉积和焊接。在此基础上，对SCM435淬火钢试件进行了镜面磨削试验。因此，通过合理定量的修整工艺生成良好的工作表面，实现了镜面磨削，获得了粗糙度Rz&lt；0.4μm的磨削表面。此外，还证实了在磨削过程中，超声激活的冷却液使磨削表面粗糙度Rz降到了0.2μm以下，使工作表面保持在良好的状态。较少

This research was done to improve the controllability of the mirror grinding process by proposing the effective method to keep good wheel performance during grinding by generating and evaluating the working surface condition.First of all, the generation process of the working surface with dressing was examined based on the change in the cutting-edge distribution. As a result, it was clarified that the critical value of the depth-of-cut divides the dressing mode into the shedding and the micro-breaking. Moreover, it was found out that the spark-out in dressing is an important process to improve the ground surface roughness. Since the spark-out suppresses the scratch generation on ground surface, the roughness is improved remarkably. However, an excessive spark-out decreases the chip pockets and makes loading easy, and then the ground surface roughness becomes worse in spite of its high cutting-edge density.In the next, the improvement effect of the ultrasonically activated coolant on th … More e ground surface roughness was examined. It is observed that the activation of coolant with the ultrasonic wave of MHz-order frequency decreases generating and depth of scratch remarkably. And then, the mechanism was examined based on the observation and the evaluation of the coolant supply condition and the working surface condition of grinding wheel. As a result, it was found out that the ultrasonically activated coolant is able to overcome the air flow around the wheel, and then to reach the grinding point easily. This represents that the coolant acts steadily in the grinding points to prevent the deposition and welding of chips. Furthermore, the wear of the wheel is decreased.Based on these results, the mirror grinding was tried for the specimen made from hardening steel SCM435. Consequently, the mirror grinding to obtain the ground surface of roughness Rz<0.4μm was achieved by generating a good working surface by reasonable and quantitative dressing process. In addition, it was confirmed that the ground surface roughness Rz was decreased lower than 0.2μm with the ultrasonically activated coolant that keeps working surface in good condition during grinding. Less