CNC machining tools can be divided into two categories: conventional tools and modular tools. Modular cutting tools are the direction of development. The main advantages of developing modular tools: reduce tool change downtime, increase production and processing time; speed up tool change and installation time, improve the economy of small batch production; improve the standardization and rationalization of tools; improve tool management and flexible processing level; expand the utilization rate of the tool and give full play to the performance of the tool; effectively eliminate the interruption of tool measurement work, and can use off-line pre-setting. In fact, due to the development of modular tools, CNC tools have formed three major systems, namely turning tool systems, drilling tool systems and boring and milling tool systems.
(1) Structurally, it can be divided into: ①Integral type ②Inlaid type It can be divided into welding type and machine clamp type. The machine-clamp type is divided into indexable and non-indexable according to the structure of the tool body; ③Vibration-absorbing type When the ratio of the working arm length and diameter of the tool is large, in order to reduce the vibration of the tool and improve the machining accuracy, this type is often used Tools; ④ Internally cooled cutting fluid is sprayed from the nozzle hole into the cutting edge of the tool through the interior of the cutter body; ⑤ Special types such as composite tools, reversible threading tools, etc.
(2) From the materials used in manufacturing, it can be divided into ① High-speed steel tools. High-speed steel is usually a parison material, with better toughness than cemented carbide, and harder hardness, wear resistance and red hardness. The alloy is poor and not suitable for cutting materials with higher hardness, nor is it suitable for high-speed cutting. High-speed steel knives need to be sharpened by the manufacturer before use, and they are easy to sharpen and are suitable for various non-standard knives with special needs. ② Carbide cutting tools Carbide inserts have excellent cutting performance and are widely used in CNC turning. Carbide inserts are available in a series of standard specifications. Specific technical parameters and cutting performance are provided by the tool manufacturer. Carbide inserts are divided into three categories according to international standards: P type, M type, and K type. Category P - suitable for processing steel, long-chip malleable cast iron (equivalent to my country's YT category) M category - suitable for processing austenitic stainless steel, cast iron, high manganese steel, alloy cast iron, etc. (equivalent to my country's YW category) M-S Class - Suitable for processing heat-resistant alloys and titanium alloys K Class - Suitable for processing cast iron, chilled cast iron, short-chip malleable cast iron, non-titanium alloys (equivalent to my country's YG class) K-N Class - Suitable for processing aluminum, non-titanium alloys Ferrous alloy K-H type - suitable for processing hardened materials ③ Ceramic tools ④ Cubic boron nitride tools ⑤ Diamond tools
(3) From the cutting technology, it can be divided into ① Turning tools are divided into outer circle, inner hole, External threads, internal threads, grooving, end face cutting, end face ring grooves, cutting, etc. CNC lathes generally use standard machine clamps for indexable tools. The inserts and cutter bodies of machine-clamped indexable tools are standard, and the insert materials are carbide, coated carbide and high-speed steel. The types of indexable tools for CNC lathe machine clamps include external cylindrical tools, external thread tools, internal cylindrical tools, internal thread tools, cutting tools, and hole processing tools (including center hole drills, boring tools, taps, etc.). Machine-clamped indexable tools usually use structures such as screws, screw pressure plates, lever pins or wedges to clamp non-regrindable blades. Conventional turning tools are long square cutter bodies or cylindrical cutter shanks. The square cutter body is generally fixed with grooved cutter holder screws. The cylindrical cutter holder is fixed with sleeve screws. The connection between them and the machine tool cutter is through the grooved tool holder and the sleeve connecting rod. In the modular turning tool system, the connection of the cutter head is mostly a rack-type handle connection, while the connection between the cutter head and the cutter body is a "insertion quick-change system". It can be used for both external turning and internal boring, and is also suitable for automatic tool changing systems in turning centers. The tools used in CNC lathes are divided into three categories in terms of cutting methods: circular surface cutting tools, end face cutting tools and center hole tools. ②Drilling tools are divided into small holes, short holes, deep holes, tapping, reaming, etc. Drilling tools can be used in CNC lathes and turning centers, as well as CNC boring and milling machines and machining centers. Therefore, it has various structures and connection forms. There are many types of straight shank, straight shank screw fixing, tapered shank, threaded connection, modular connection (conical or cylindrical connection), etc. ③ Boring tools are divided into rough boring, fine boring and other tools. Boring tools can be structurally divided into integral boring tool holders, modular boring tool holders and boring heads. From the processing technology requirements, it can be divided into rough boring tools and fine boring tools. ④Milling tools: face milling, end milling, three-side milling and other cutting tools. ●Face milling cutter (also called end milling cutter) There are cutting edges on the circumferential surface and end face of the face milling cutter, and the end cutting edge is the secondary cutting edge.
Face milling cutters are mostly made of sleeve-type tooth insert structure and indexable blade clamp structure. The cutter tooth material is high-speed steel or carbide, and the cutter body is 40Cr. ●End mill End mill is the most commonly used milling cutter on CNC machine tools. There are cutting edges on the cylindrical surface and end face of the end mill, and they can be cut simultaneously or separately. The structures include integral type and machine-clamp type. High-speed steel and carbide are common materials for the working part of milling cutters. ●Mold milling cutters are developed from end mills. They can be divided into three types: conical end mills, cylindrical ball end mills and conical ball end mills. The handles are straight or flat. Straight and Morse taper shanks. Its structural feature is that the ball head or end face is covered with cutting edges. The circumferential edge is connected with the ball head edge in an arc, and can be fed in radial and axial directions. The working part of the milling cutter is made of high-speed steel or carbide. ●Keyway milling cutter ●Drum milling cutter ●Form milling cutter
(4) Special tools The special tools have self-tightening chucks with handles, strong spring chuck tool handles, reversible (automatic reverse ) Tapping chuck tool holders, speed-increasing chuck tool holders, composite tools and adapters, etc. 2. Characteristics of CNC machining tools In order to achieve the goals of high efficiency, versatility, quick change, and economy, CNC machining tools should have the following characteristics compared with ordinary metal cutting tools: ●The blades and tool handles are highly generalized, standardized, and serialized. ●The durability of the blade or tool and the reasonableness of the economic life indicators. ●Standardization and typification of tool or insert geometric parameters and cutting parameters. ●The blade or tool material and cutting parameters should match the material being processed. ●Tools should have high precision, including the shape accuracy of the tool, the relative position accuracy of the blade and tool holder to the machine tool spindle, the indexing of the blade and tool holder, and the repeatability of disassembly and assembly. ●The tool handle should have high strength, rigidity and wear resistance. ●The installed weight of the tool holder or tool system is limited. ●There are requirements for the position and direction of cutting of the blade and tool handle. ●The positioning reference of the blade and tool holder and the automatic tool changing system should be optimized. The cutting tools used on CNC machine tools should meet the requirements of easy installation and adjustment, good rigidity, high precision, and good durability.