The machine tools are mainly classified according to the processing methods and the tools used. According to the method of preparing machine tool models formulated by the state, the machine tools are divided into 11 categories: lathes, drilling machines, boring machines, grinders, gear processing machines, thread processing machines, milling machines, planing and slotting machines, broaching machines, sawing machines and other machine tools. In each type of machine tool, it is divided into several groups according to the process scope, layout type and structural performance, and each group is divided into several systems (series).
In addition to the above basic classification methods, there are other classification methods:
1. The machine tools can be divided into:
(1) Universal machine tools have a wide range of processes, and can complete the processing of various types of parts in different processes, such as horizontal lathes, universal cylindrical grinders and radial drilling machines.
(2) The process scope of special machine tool is the narrowest. It is generally designed and manufactured for a specific process of a specific part, such as various combined drilling and boring machine tools used for mass production of automobile parts.
(3) Specialized machine tools have a narrow range of processes. They are specially designed and manufactured for processing certain parts or processes, such as tooth relieving lathes, lead screw milling machines, etc.
2. According to the number of main organs of the machine tool, it can be divided into single axis, multi axis, single tool, multi tool machine tools, etc.
3. According to the degree of automation, it can be divided into ordinary, semi-automatic and automatic machine tools.
4. According to the working accuracy of machine tools, it can be divided into ordinary precision machine tools, precision machine tools and high-precision machine tools.
5. According to weight and size, it can be divided into instrument machine tools, medium machine tools (general machine tools), large machine tools (with a mass of more than 10t), heavy machine tools (with a mass of more than 30t) and super heavy machine tools (with a mass of more than 100t).
The automatic machine tool has a complete automatic working cycle, including automatic loading and unloading of workpieces, and can automatically process workpieces continuously. The semi-automatic machine tool also has a complete automatic working cycle, but the loading and unloading of the workpiece still needs to be completed manually, so it cannot be processed continuously.
The cutting process of machine tool is realized by the relative motion between the tool and the workpiece. Its motion can be divided into surface forming motion and auxiliary motion.
1. Auxiliary movements mainly include rapid approaching and exiting of tools or workpieces, adjustment of machine tool component positions, workpiece indexing, tool rest indexing, feeding and clamping, starting, speed changing, reversing, stopping and automatic tool changing.
2. The surface forming movement is the movement that enables the workpiece to obtain the required surface shape and size. It includes the main movement, feed movement and cut in movement. The main movement is the movement that plays the main role when stripping excess materials from the workpiece blank. It can be the rotary movement of the workpiece (such as turning), linear movement (such as planing on the gantry planer), or the rotary movement of the cutter (such as milling and drilling) or linear movement (such as slotting and broaching); The cut in motion is the motion that makes the tool cut into the workpiece surface to a certain depth, and its role is to cut a certain thickness of material from the workpiece surface in every cutting stroke, such as the transverse cut in motion of the small tool holder when turning the excircle; Feed movement refers to the movement of the tool and the part to be machined of the workpiece to make the cutting continue, such as the movement of the tool slide along the machine tool guide when turning the excircle.