STUDY ON ULTRA-HIGH SPEED CUT-OFF GRINDING

磨削效率与砂轮圆周速度成正比。因此，如果圆周速度增加，则磨削效率将提高。研制了圆周速度超过400 m/s的超高速磨削机床。在磨削实验中，由于旋转轮的低失效强度，圆周速度被限制在300 m/s以下。在该项目中，开发了用于切割磨削的cBN砂轮（刀片），其最大圆周速度为400 m/s。(1)法兰与叶片的结构分析为实现超高速磨削的实际生产，对带中心孔的叶片采用法兰系统进行固定。建立了综合考虑中心孔影响和刃缘摩擦的切断磨削分析模型。结果表明，当增大翼缘与叶片之间的摩擦力时，可以实现400 m/s的圆周速度， ...更多信息 翼缘和叶片采用钛合金或CFRP，比弹性模量高。(2)根据分析结果，制造了法兰和刀片，并使用旋转试验机进行了超高速域（20，000 ~ 35，000 rpm（459 m/s））的旋转失效试验。在仅以30，000 rpm对碳钢叶片进行旋转测试之后，沿着周向方向在叶片上保留塑性变形。在用低压法兰固定叶片的情况下，在旋转试验后，在用于固定螺栓的孔周围发现塑性变形。然而，在大的定影压力下，塑性变形没有被识别。(3)超高速切断磨削试验在旋压试验的基础上，采用钛合金法兰和钛芯金属结合剂砂轮进行超高速切断磨削。成功地进行了圆周速度为400 m/s的磨削试验。少

Grinding efficiency is in proportion to peripheral speed of grinding wheel. Therefore, if the peripheral speed is increased, grinding efficiency will be improved. An ultra-high-speed grinding machine wa developed whose peripheral speed is over 400m/s. The peripheral speed is limited below 300 m/s in the grinding experiment, because of a low failure strength of the rotating wheel. In this project, cBN wheels (blades) for cut-off grinding were developed whose maximum peripheral speed is 400 m/s.(1) Structural analysis of flange and bladeTo realize the actual production utilized the ultra-high speed grinding, the blade with the center hole was fixed with a flange system. An analytical model for cut-off grinding was created to consider both the effect of the center hole and friction between the flange and the blade. As a result, it is found that the peripheral speed of 400 m/s can be realized, when the friction force between the flange and the blade is increased, and material such as titan … More ium alloy or CFRP is used for the flange and blade, whose specific young's modulus is high.(2) Ultra-high speed rotational test of blade for cut-off grindingBased on the analytical result, flange and blade were manufactured and rotational failure tests in ultra-high speed domain (20,000〜35,000 rpm (459 m/s)) were carried out using a spin tester. After rotational test of the carbon steel blade only at 30,000 rpm, plastic deformation remained on the blade along the circumferential direction. In the case of the blade that is fixed with flange with low pressure, plastic deformation was recognized around the holes for fixing bolts after rotational test. However, plastic deformation was not recognized in large fixing pressure.(3) Ultra-high speed cut-off grinding experimentBased on the results of the spin tests, flange made by titanium alloy and the metal bonded grinding wheel with titanium core was used for ultra-high speed cut-off grinding. Grinding tests with peripheral-speed of 400 m/s were successfully carried out. Less