我厂生产多种小型内燃机,其中曲轴斜油孔口(见图1)要抛光,工艺要求粗糙度Ra0.8μm(▽7).原来采用三角刮刀沿孔口360°刮削一圈,结果孔口呈多角形,且工作效率也较低。以后改为使用夹持抛光用棒的JIZ型手枪电钻,但因它的噪声大,重量为3.2kg,故操作工人不满意。最近,我们采用S40型风动工具作为动力源。该工具仅重0.7kg,转速1600r/min,噪声小,芯子部分开三条等分槽,把抛光用棒插入其内,用螺母夹紧,夹持牢固,拆装方便(见图2)。在棒的头部穿进一块橡胶衬垫,一块“00”号铁砂 I plant a variety of small internal combustion engines, of which crankshaft oblique oil orifice (see Figure 1) to be polished, the process requires roughness Ra0.8μm (▽ 7). The original triangular scraper along the orifice 360 ​​° scraping a circle, the results of the orifice Polygonal, and work efficiency is lower. Later changed to use a clip-polished rod JIZ pistol drill, but because of its noise, weight is 3.2kg, so the operating workers are not satisfied. Recently, we use S40-type pneumatic tools as a power source. The tool weighs only 0.7kg, speed 1600r / min, the noise is small, the core part of the open three equalizer slot, the polished rod inserted into it, with a nut clamping, clamping firm, easy disassembly (see Figure 2). Put a piece of rubber liner in the stick’s head, a “00” iron sand