What are the types of hole machining tools?

Hole machining tools can be divided into drilling tools, boring tools, reaming tools and reaming tools.

(1) There are many drilling tools, mainly ordinary twist drills, indexable shallow hole drills and flat drills. With the machining center drilling usually use ordinary twist drill, ordinary twist drill is mainly composed of the working part and the shank. The tool shank part is straight shank and taper shank. Straight shank tool handle is mainly spring chuck handle, which has the advantages of automatic centering, automatic elimination of deflection, so the small size of the tool to choose the type. The working part includes a cutting part and a guide part. As shown, the cutting part of the twist drill has two main cutting edges, two auxiliary cutting edges and one chisel edge. The guiding part of the twist drill plays the role of guiding, repairing and removing chips and conveying cutting fluid. Twist drills are generally used for rough machining of holes with low precision. Since the clamp used in the machining center does not have a drill sleeve centering guide, the drill bit is prone to yaw movement during high-speed rotary cutting, and the chisel edge of the drill bit is long. Therefore, when drilling, the center hole should be drilled with the center to guide the drill bit.

(2) the main feature of boring is to obtain accurate hole size, get high-precision roundness, cylindricity and surface roughness, so the hole with high precision can be used to ensure boring. Boring cutter according to the number of cutting edges can be divided into single-edged boring cutter and double-edged boring cutter, boring through hole, blind hole, step hole can be completed by single-edged boring cutter; processing large diameter hole, can be used double-edged boring cutter. In addition, there is a fine-tuning boring tool, in the machining center is currently more use of fine-tuning boring tool for hole fine boring, this boring tool adjustment is convenient and high precision.

(3) The processing center mostly uses reaming drills for reaming, and reaming knives are also used for reaming. For example, when the reaming diameter is small, a straight shank reaming knife can be used; When the reaming diameter is medium, a taper shank reaming knife can be used; when the reaming diameter is large, a sleeve reaming knife can be used. In addition, the keyway milling cutter or end mill can be used for reaming, which is higher than the controllable machining accuracy of ordinary reaming drill. Because there are cutting edges on the cylindrical surface and end face of the end mill, it can be cut at the same time, or it can be cut separately, and the tool of the machining center can be fed axially, or it can be fed horizontally like a horizontal milling machine. Therefore, in the machining center with spiral interpolation instructions, the use of end mill reaming, only a tool can be used to complete a number of different aperture processing.

(4) Reaming is generally in the later stage of processing, and most of them are used for finishing holes with a diameter less than Φ25mm. Because the number of reaming teeth, good guidance, shallow chip groove, good rigidity, the size of the hole after processing accuracy can reach IT7 ~ IT9 level, surface roughness can reach Ra1.6 ~ 0.8 μm. Ordinary standard reamers have straight shank, taper shank and sleeve type. The diameter of the small hole straight shank reamer is 16mm, the diameter of the straight shank is 6~20mm, the diameter of the taper shank reamer is 10~32mm, and the diameter of the sleeve reamer is 25~80mm. It can be selected according to the needs during processing.