Discussion on the hole cutting tool of NC lathe

The tools used for reaming on the machining center of NC milling machine also include machine clamp cemented carbide blade, single edge reamer and floating reamer. The reaming tool performs micro cutting on the machined hole, and the working part (cutting edge part) of the reamer is divided into cutting part and calibration part. The cutting part is conical and undertakes the main cutting work. The calibration part includes cylinder and inverted cone. The reasonable cutting parameters are; The back draft is taken as the reaming allowance (Rough reaming allowance is 0.15-0.35mm, fine reaming allowance is 0.05-0.15mm), and the feed rate of low-speed cutting (Rough reaming steel is 5-7m / min, fine reaming is 2-5) is generally 0.2-1.2mm. If the feed rate is too small, slip and scratch will occur. At the same time, the coolant shall be reasonably selected during reaming, and the emulsion shall be selected for reaming on steel; Kerosene is sometimes used to ream holes in iron castings.

Reaming is a processing method of semi finishing and finishing the hole. Its processing accuracy is generally lt9-lt6, and the surface roughness value is r, which is 1.6-0.4um. However, the reaming generally cannot correct the position error of the hole. Therefore, before reaming, the position accuracy of the hole should be guaranteed by the previous process. The standard machine knife is shown in Figure 3.13. The reamer is composed of working part, neck and bing part. The shank forms include straight shank, cone Bing and sleeve. The cylindrical part is mainly used to guide the reamer, calibrate and show the machining hole, and the inverted cone is mainly used to reduce the friction between the reamer and the hole wall and prevent the expansion of the hole diameter.