对于φ50以下的内孔,过去,我们是应用铸铁棒来研磨加工的,但是,总达不到▽▽▽▽10以上表面光洁度的要求。同时,利用铸铁棒研磨,一般还需要制造一个固定直径的研磨棒三件,显得也很麻烦。并且研磨以后,孔径易产生锥度、椭圓度和喇叭口等现象。若用可调整涨胎也很难满足技术要求。后来,我们采用了铅质研磨棒,进行研磨,不仅精度得到满足,而且表 For φ50 below the hole, in the past, we use the cast iron rod to grind the processing, however, does not always meet the ▽ ▽ ▽ ▽ 10 surface finish requirements. At the same time, the use of cast iron rod grinding, the general also need to create a fixed diameter grinding rod three, it is also very troublesome. And after grinding, the aperture is easy to produce taper, ovality and bell mouth and so on. If the adjustable tire is also difficult to meet the technical requirements. Later, we used a lead-based grinding rod for grinding, not only the accuracy was satisfied, but also the table