我厂在加工HT20-40铸铁机座(图1)四个φ42~(+0.34)孔时,采用高效扩孔铰刀(图2),在Z35摇臂钻床上加工,效果较好。其尺寸偏差不大于0.03毫米,加工光洁度稳定在(?)6～7,生产效率提高2倍以上。刀具结构及特点:1.扩孔铰刀由扩孔刀1、传送块2、刀排3组成。传送块的内螺纹与刀排联接,以传递扭矩。扩孔刀1:30锥孔与刀排吻合,以便于制造、更换和刃磨。 When machining four φ42 ~ (+0.34) holes of HT20-40 cast iron machine base (Fig. 1), we use high-efficiency reaming reamer (Fig. 2) to process on Z35 radial drilling machine, the effect is better. The size deviation of not more than 0.03 mm, processing and stability at (?) 6 to 7, more than 2 times the production efficiency. Tool structure and features: 1. Reaming reamer reaming cutter 1, transfer block 2, knife row 3 components. The inner thread of the transfer block is connected to the knife row to transmit the torque. Reaming knife 1:30 cone hole coincides with the knife row, in order to facilitate the manufacture, replacement and sharpening.