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

为实现内磨机旋转修整器的机内修整，采用修整器转速相对于砂轮转速非常慢的修整系统，主轴采用轴颈轴承，达到40 N/μm的高刚度。修整器与砂轮的接触点采用声发射传感器检测，精度为0.1μm。研究了两种v型旋转金刚石修整器——单层浸渍金刚石修整器和金属结合金刚石修整器的修整性能。对淬硬钢进行内插式磨削，研究了修整器类型对磨削性能的影响。总结了以下结果。1)当以极慢速度旋转的修整器应用于直径较小的砂轮时，砂轮表面在宽方向上的一部分可能不与修整器接触。这种修整的不均匀性可以通过使用修整器来减少，修整器上的钻石颗粒以短间隔排列。2)金属结合剂金刚石修整器的优点是金刚石颗粒间距易于控制，可用于小直径砂轮的修整。3)采用玻璃化气相色谱杯轮法对金属结合金刚石修整器进行高轮廓精度的修整。4)金属结合金刚石修整器的磨削力比浸渍金刚石修整器更稳定。5)小粒度金属结合金刚石修整器增大磨削力，降低成品表面粗糙度，减小径向砂轮磨损。对于140目粒度的砂轮，修整器的最佳粒度为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.