DEFORM- AND EXHAUST-CONTROLL OF CHIP IN DRILLING WITH A NEW TYPE TWIST DRILL

为了在连续进给下用麻花钻进行深孔钻削时排出切屑，切屑必须是连续的类型并且可以通过钻槽移动，因为分段式切屑倾向于堵塞钻槽。自由生成的切屑为圆锥螺旋型。因此，钻屑槽和钻孔必须使其变形为较小的直径或螺距等于槽距的长螺距螺旋型切屑，由于常规钻头的主切削刃较宽，几乎与半径矢量相对应，因此进行半正交切削，自由生成的切屑为小螺距的圆锥螺旋型切屑。一种新型麻花钻，每侧有两个切削刃。每个切削刃独立地切削工件材料。每个切削刃产生的切屑并不完全统一。由内侧切削刃产生的切屑附着在由外侧切削刃产生的切屑上，该切屑是主切屑。这是切屑变形和排屑控制的基础。由于外刃倾角较大，这种锥形螺旋型切屑的螺距较长，在深孔加工中，槽型和孔型将其控制为长螺距型。

In order to exhaust chip in deep hole drilling with a twist drill under continuous feed, it is necessary that the chip is a continuous type and can move through the drill flute, because the segment type chip tends to clog the drill flutes. The freely generated chip is the conical helix type. Therefore, it is necessary that the drill flute and the drilled hole deform it to the smaller diameter or to the long pitch helix type chip, whose pitch is equal to the flute pitch.As the main cutting edge of a conventional drill is wide and almost corresponds to the radius vector, the semi-orthogonal cutting is carried out, and the freely generated chip is a conical helix type one with small pitch. It is difficult to deform it to the above mentioned chips.A new type twist drill has two cutting edges on each side. Each cutting edge cuts work material independently. The chips generated by each cutting edge are not perfectly unified. The chip by the inside cutting edge is attached to the chip generated by the outside cutting edge which is main chip. This is the basis to the deform- and exhaust-controll of chip. As the outside cutting edge has a large oblique angle, this conical helix type chip has longer pitch, and the flute and the drilled hole controll it to the long pitch type in deep hole drilling.