Milling machine is a machine tool for milling workpieces with milling cutter. Milling machines can not only mill planes, grooves, gear teeth, threads and spline shafts, but also process more complex contours, with higher efficiency than planers, and are widely used in machinery manufacturing and repair departments.
The earliest milling machine was a horizontal milling machine created by American Whitney in 18 18. In order to mill the spiral groove of twist drill, American Brown made the first universal milling machine in 1862, which is the prototype of the lifting table milling machine. 1884 or so, the gantry milling machine reappeared; In the 1920s, a semi-automatic milling machine appeared, and the workbench can be automatically switched between "feed-speed" or "speed-feed" by using a stop.
After 1950, the control system of milling machine developed rapidly, and the application of digital control greatly improved the automation degree of milling machine. Especially after 1970s, microprocessor digital control system and automatic tool changing system were applied to milling machines, which expanded the machining range of milling machines and improved the machining accuracy and efficiency.
There are many kinds of milling machines, which are generally distinguished by layout and scope of application. There are mainly lifting table milling machines, gantry milling machines, single-column milling machines and single-arm milling machines, instrument milling machines and tool milling machines.
There are universal, horizontal and vertical lifting table milling machines, which are mainly used to process small and medium-sized parts and are widely used. Gantry milling machines include gantry milling and boring machines, gantry milling and planing machines and double-column milling machines, all of which are used to process large parts. The horizontal milling head of single-column milling machine can move along the column guide rail, and the workbench can feed longitudinally; The vertical milling head of a single-arm milling machine can move horizontally along the cantilever guide rail, and the cantilever can also adjust its height along the column guide rail. Single-column milling machine and single-arm milling machine are both used to process large parts.
Instrument milling machine is a small lifting table milling machine, which is used to process small parts such as instruments. Tool milling machine is mainly used for mold and tool manufacturing, equipped with vertical milling head, universal angle worktable and plugging head, and can also be used for drilling, boring and slotting. Other milling machines include keyway milling machine, cam milling machine, crankshaft milling machine, roller journal milling machine and square ingot milling machine, all of which are special milling machines for processing corresponding workpieces.
In addition, according to the control mode, milling machines can be divided into copying milling machines, program-controlled milling machines and CNC milling machines.