の フライス盤 is a multi-tooth rotary tool, and each of its teeth is equivalent to a turning tool fixed on the rotary surface of the milling cutter. When milling, the cutting edges that participate in cutting are longer, and there is no idle travel, and Vc is also higher, so the productivity is higher. Many types of milling cutters have different structures and a wide range of applications. According to their uses, they can be divided into three categories: milling cutters for processing planes, milling cutters for processing grooves, and milling cutters for processing forming surfaces. Milling cutters of general specifications have been standardized and are generally produced by professional tool factories. Here we introduce the characteristics of several commonly used milling cutters and their applicable scope.
Cylindrical Milling Cutter
The cylindrical milling cutter is as follows. It is generally made of high-speed steel as a whole, with spiral cutting edges distributed on the cylindrical surface, and no secondary cutting edges. The spiral teeth gradually cut into and out of the workpiece during cutting, so the cutting process is relatively smooth. It is mainly used for processing narrow planes with a width less than the length of the milling cutter on horizontal milling machines.
Depending on the processing requirements, cylindrical milling cutters are divided into coarse teeth and fine teeth. Coarse teeth have large chip grooves and are used for rough processing, while fine teeth are used for fine processing. When the outer diameter of the milling cutter is large, it is often made into an inlaid tooth.
Face Milling Cutter
Face milling cutter, the main cutting edge is distributed on the surface of the cylinder or cone, the end cutting edge is the secondary cutting edge, and the axis of the milling cutter is perpendicular to the surface to be processed. According to the material of the teeth, it can be divided into two categories: high-speed steel and carbide. Most of them are made into a sleeve-type tooth structure, and the cutter body material is 40Cr.
Compared with high-speed steel milling cutters, carbide face milling cutters have higher milling speeds and better surface quality, and can process workpieces with hard skin and hardened layers, so they are widely used. Carbide face milling cutters can be divided into three types according to the installation methods of the blades and teeth: integral type, machine clamp-welded type, and indexable type.
Face milling cutters are mainly used on vertical milling machines or horizontal milling machines to process step surfaces and planes. They are particularly suitable for processing larger planes. Face milling cutters with a main deflection angle of 90° can mill wider step surfaces at the bottom. When using face milling cutters to process planes, more teeth are involved in cutting at the same time, and there is also a finishing effect of the secondary cutting edge, which makes the surface roughness value of the processing small. Therefore, a larger cutting amount can be used, the productivity is high, and it is widely used.
エンドミル
エンドミル is the most commonly used milling cutter in CNC milling. In its structure, the cutting edge on the cylindrical surface is the main cutting edge, and the secondary cutting edge is distributed on the end face. The main cutting edge is generally a spiral tooth, which can increase the cutting stability and improve the processing accuracy. Since there is no cutting edge at the center of the end face of the ordinary end mill, the end mill cannot be fed axially when working, and the end face edge is mainly used to process the bottom plane perpendicular to the side.
To improve the chip curling, increase the chip space, and prevent chip blockage, the number of teeth is relatively small, and the radius of the chip groove arc is larger. Generally, the number of teeth of the coarse-tooth end mill is Z=3~4, the number of teeth of the fine-tooth end mill is Z=5~8, the sleeve structure is Z=10~20, and the radius of the chip groove arc r=2~5mm. When the diameter of the end mill is large, it can also be made into an unequal pitch structure to enhance the anti-vibration effect and make the cutting process stable.
End mills with smaller diameters are generally made into handles. End mills with diameters of φ2 to φ71mm have straight shanks; end mills with diameters of φ6 to φ63mm have Morse push shanks. End mills with diameters of φ25 to φ80mm have 7:24 taper shanks with screw holes, which are used to tighten the tool. End mills with diameters of φ40 to φ160mm can be made into sleeve structures.
End mills are mainly used for processing grooves, step surfaces, and forming surfaces using molds. In addition, there are coarse-toothed large helix angle end mills, corn milling cutters, carbide corrugated edge end mills, etc. They have larger diameters, can use large feed rates, and have high productivity.
Three Sided Edge Milling Cutter
Three-edge milling cutters can be divided into straight-tooth three-edge milling cutters and staggered-tooth three-edge milling cutters. They are mainly used on horizontal milling machines to process step surfaces and shallow grooves that penetrate one or both ends. In addition to the main cutting edge on the circumference, three-edge milling cutters also have secondary cutting edges on both sides, which improves cutting conditions, increases cutting efficiency, and reduces surface roughness values. However, the width size changes greatly after regrinding, and the toothed three-edge milling cutter can solve this problem.
Saw Blade Milling Cutter
The saw blade milling cutter is as follows. The saw blade milling cutter itself is very thin and has only teeth on the circumference. It is used to cut off workpieces and mill narrow grooves. To avoid clamping the cutter, its thickness decreases from the edge to the center, forming a secondary deflection angle on both sides.
Keyway Milling Cutter
Keyway milling cutter. Its appearance is similar to that of an end mill, but the difference is that it has only two spiral teeth on the circumference. The blades of its end teeth extend to the center, which is like an end mill and a drill. Therefore, when milling keyways that are blocked at both ends, an appropriate amount of axial feed can be made. It is mainly used to process round head closed keyways. When using it for processing, multiple vertical feeds and longitudinal feeds are required to complete the keyway processing.
