CNC machining tools can be divided into two categories: conventional tools and modular tools. Modular tools are the direction of development. The main advantages of developing modular tools: reducing tool downtime, increasing production and processing time; speeding up tool change and installation time, improving the economics of small batch production; improving the standardization and rationalization of tools; improving tool management and flexible processing The level of the tool; expand the utilization of the tool, give full play to the performance of the tool; effectively eliminate the interruption of the tool measurement work, can be used for off-line pre-adjustment. In fact, due to the development of modular tools, CNC tools have formed three major systems, namely the turning tool system, the drilling tool system and the boring and milling tool system.
1. Structurally can be divided
1 integral type 2 mosaic type 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 cutter body;
3 damping type When the working arm length and diameter of the tool are relatively large, in order to reduce the vibration of the tool and improve the machining accuracy, such a tool is often used;
4 The inner cooling cutting fluid is sprayed from the inside of the cutter body through the injection hole to the cutting edge portion of the cutter;
5 special types such as composite tools, reversible tapping tools.
2. Divided into materials used in manufacturing
1 High-speed steel cutter High-speed steel is usually a parison material. Its toughness is better than that of hard alloy. Its hardness, wear resistance and red hardness are worse than that of hard alloy. It is not suitable for cutting high hardness materials and is not suitable for high-speed cutting. High-speed steel tools need to be sharpened by the producer before use, and the sharpening is convenient, suitable for non-standard tools of various special needs.
2 Carbide tools Carbide inserts have excellent cutting performance and are widely used in CNC turning. Carbide inserts are available in standard sizes. The specific technical parameters and cutting performance are provided by the tool manufacturer.
Carbide inserts are divided into three categories according to international standards: P, M, and K.
Class P - suitable for processing steel, long chip malleable cast iron (equivalent to China's YT category)
Class M - suitable for processing austenitic stainless steel, cast iron, high manganese steel, alloy cast iron, etc. (equivalent to China's YW category)
MS class - suitable for processing heat-resistant alloys and titanium alloys K - suitable for processing cast iron, chilled cast iron, short-grain malleable cast iron, non-titanium alloy (equivalent to China's YG category)
KN class - suitable for processing aluminum, non-ferrous alloy KH class - suitable for processing hardened materials
3 ceramic tools 4 cubic boron nitride tools 5 diamond tools
3. From the cutting process can be divided into
1 Turning tools are divided into outer circle, inner hole, external thread, internal thread, grooving, cutting end face, cutting end ring groove, cutting and so on.
CNC lathes generally use standard machine clamp indexable tools. The inserts and cutters of the indexable indexing tool are standard, and the insert material is made of hard alloy, coated hard alloy and high speed steel.
CNC lathe machine clamp indexable tool types include external tools, external thread tools, internal circle tools, internal thread tools, cutting tools, hole machining tools (including center hole drills, boring tools, taps, etc.).
Machine clamps can be indexed. When the blade is not re-grinded, screws, screw press plates, lever pins or wedges are usually used.
A conventional turning tool is a long square cutter body or a cylindrical cutter bar.
The square cutter body is generally fixed by a slotted knife holder screw fastening method. The cylindrical shank is fixed by a sleeve screw fastening method. The coupling between them and the machine tool holder is coupled by a slotted tool holder and a sleeve post. In a modular turning tool system, the coupling of the cutterhead is coupled with a rack-type handle, and the coupling of the cutter head to the cutter body is an "inserted quick-change system". It can be used for both external turning and internal hole boring, as well as for automatic tool change systems in turning centers.
The tools used in CNC lathes are divided into three categories from cutting methods: round surface cutting tools, face cutting tools, and center hole tools.
2 Drilling tools are divided into small holes, short holes, deep holes, tapping threads, reaming holes, etc.
Drilling tools can be used in CNC lathes, turning centers, and in CNC boring and milling machines and machining centers. Therefore, its structure and connection form are various. There are straight shank, straight shank screw setting, taper shank, threaded connection, modular connection (conical or cylindrical connection) and so on.
3 boring tools are divided into rough, fine and other tools.
The file can be divided into a single boring handle, a modular boring handle and a hoe. From the processing requirements, it can be divided into rough boring tools and fine boring tools.
4 milling tools face milling, vertical milling, three-sided milling and other tools.
â— Face milling cutter (also called end mill)
The face milling cutter has cutting edges on both the circumferential surface and the end surface, and the end cutting edge is a minor cutting edge. The face milling cutter is made of a sleeve type insert structure and a blade holder indexable structure. The cutter material is high speed steel or hard alloy, and the cutter body is 40Cr.
â—End mill
End mills are the most widely used milling cutters on CNC machines. End mills have cutting edges on the cylindrical surface and on the end faces. They can be cut at the same time or cut separately. The structure is integral and machine clamped, etc. High-speed steel and hard alloy are common materials for the working part of the milling cutter.
â—Mold milling cutter
Mold milling cutters are developed by end mills and can be divided into conical end mills, cylindrical ball end mills and conical ball end mills. The handle has straight shank, flat straight shank and Morse taper shank. Its structural feature is that the ball or end face is covered with a cutting edge, and the circumferential edge is connected with the ball edge of the ball to make radial and axial feed. The working part of the milling cutter is made of high speed steel or hard alloy.
â—Keyway milling cutter â—Drum milling cutter â—Forming milling cutter
4. Special tool
Special-purpose knives include self-tightening shank with handle, strong spring collet shank, reversible (automatic reverse) tapping chuck shank, speed-increasing chuck shank, compound cutter and post.
5. The characteristics of CNC machining tools
In order to achieve high efficiency, versatility, quick change, and economical purposes, CNC machining tools should have the following characteristics compared with ordinary metal cutting tools:
â—Generalization, standardization and serialization of the height of the blade and the shank.
â— The durability of the blade or tool and the rationality of the economic life index.
â— Normalization and characterization of tool or blade geometry and cutting parameters.
• The blade or tool material and cutting parameters should match the material being machined.
â— The tool should have high precision, including the shape accuracy of the tool, the relative positional accuracy of the blade and the tool holder to the machine tool spindle, the indexing of the insert and the tool holder, and the repeatability of the disassembly and assembly.
â—The strength of the shank should be high, and the rigidity and wear resistance should be good.
â— The weight of the tool holder or tool system is limited.
â—The position and direction of the blade and the shank are required.
â— The positioning reference of the blade and the tool holder and the automatic tool change system should be optimized.
The tools used on CNC machine tools should meet the requirements of convenient installation and adjustment, good rigidity, high precision and good durability.