there are many processing methods for inner hole, such as drilling, reaming, reaming, mirror hole, grinding hole, drawing hole, grinding hole, yi grinding hole, rolling hole and so on. two common methods of drilling and reaming are described below.
drilling, because the twist drill length is long, the drill core diameter is small and rigid, and has the influence of the transverse edge, so drilling has the following process characteristics.
1. the drill is easy to bias and shake;
2. the aperture is easy to expand;
3. poor surface quality of the hole;
4. large axial force when drilling liu;
compared with twist drill, the structure of reaming drill has the following characteristics.
1. good rigidity; due to the small amount of reaming back cutting, less chip, reaming drill chip groove shallow and narrow, larger core diameter, increase the rigidity of the reaming drilling part.
2. good orientation; the reaming drill has 3-4 cutter teeth, the number of edges around the cutter increases, and the guiding effect is relatively enhanced.
3. better chip condition; the reaming drill does not have the cross edge to participate in the cutting, the cutting is light, may use the big feed quantity, the productivity is high, simultaneously the chip is few, the chip is smooth, not easily scratches the processed surface.
therefore, compared with drilling, reaming has higher machining accuracy, lower surface roughness, and can correct the axis error of drilling to a certain extent. the machine tool suitable for reaming is the same as drilling.