STABILIZATION OF DRESSING PERFORMANCE OF ROTARY DIAMOND DRESSER BY MEANS OF ON-THE-MACHINE PROFILE CONDITIONING

为了实现内圆磨床旋转梳妆台的在机修整，采用了梳妆台转速比砂轮转速低的修整系统，主轴采用滑动轴承，以获得40 N/μm的高刚度。采用声发射传感器检测梳妆台与修整器的接触点，测量精度为0.1μm。研究了单层孕镶金刚石梳妆台和金属结合剂金刚石梳妆台两种V形旋转修整器的修整性能。对淬硬钢进行了内圆切入磨削试验，研究了梳妆台类型对磨削性能的影响。结果如下：1）在小直径的砂轮上使用低速旋转的旋转梳妆台时，砂轮表面的圆周方向的一部分可能不与旋转梳妆台接触。这种修整的不均匀性可以通过使用金刚石颗粒以短间隔排列在其上的梳妆台来减小。2）金属结合金刚石梳妆台具有金刚石颗粒的间隔可以容易地控制的优点，因此，3）金属结合剂金刚石梳妆台可采用玻璃化GC杯修整，具有高的轮廓精度。4）金属结合剂金刚石梳妆台的磨削力比孕镶金刚石修整器的磨削力稳定; 5）小粒径的金属结合剂金刚石梳妆台提高了磨削力，降低了加工表面粗糙度，减小了砂轮径向磨损。对于#140目砂轮，梳妆台的最佳粒度为#270左右。

As a means to realize on-the-machine truing of rotary dresser for internal grinding machine, a dressing system in which the rotating speed of the dresser is very slow compared to that of the grinding wheel, is adopted, a journal bearing is used for the spindle in order to achieve a high stiffness of 40 N/μm. The contact point of dresser to the grinding wheel is detected by an AE sensor with an accuracy of 0.1μm. Dressing performance of two types of V-shaped rotary diamond dressers, a single-layered impregnated diamond dresser and a metal-bonded diamond dresser, are investigated. Internal plunge grinding of hardened steel was conducted and the effects of dresser type on the grinding performance were investigated. The following results are summarized.1)When a rotary dresser rotating with a very slow speed is applied to the grinding wheel with a small diameter, a part of grinding wheel surface in the widthwise direction may not contact the rotary dresser. This unevenness of dressing can be reduced by the use of a dresser on which the diamond grains are aligned with short intervals.2)The metal-bonded diamond dresser has the advantage that the intervals of diamond grains can be easily controlled, therefore, being available for the dresser of the grinding wheel with a small diameter.3)The metal-bonded diamond dresser can be trued with high profile accuracy by means of vitrified GC cup-wheel method.4)The metal-bonded diamond dresser brings about a grinding force more stable than that of the impregnated diamond dresser.5)The metal-bonded diamond dresser with small grain size increases the grinding force, decreases the finished surface roughness, and decreases the radial wheel wear. The optimum grain size of the dresser is around #270 for the grinding wheel of #140 mesh size.