| Budget Amount *help |
¥3,700,000 (Direct Cost: ¥3,700,000)
Fiscal Year 2005: ¥1,400,000 (Direct Cost: ¥1,400,000)
Fiscal Year 2004: ¥2,300,000 (Direct Cost: ¥2,300,000)
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| Research Abstract |
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
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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
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