Secrets You Don't Know About Milling Machines

The milling machine mainly refers to a machine tool that uses a milling cutter to process various surfaces of a workpiece. Usually, the milling cutter is mainly moved by rotation, and the movement of the workpiece and the milling cutter is the feed movement. It can process planes, grooves, various curved surfaces, gears, etc.

A milling machine is a machine tool that uses a milling cutter to mill a workpiece. In addition to milling planes, grooves, gear teeth, threads, and spline shafts, milling machines can also process more complex profiles. The efficiency is higher than that of planning machines. It is widely used in machinery manufacturing and repair departments.

A milling machine is a machine tool with a wide range of uses. It can process planes, grooves, parts with teeth, spiral surfaces, and various curved surfaces on the milling machine. In addition, it can also be used to process the surface and inner hole of the revolving body and cut off the work. When the milling machine is working, the workpiece is mounted on the worktable or the indexing head and other accessories, and the milling cutter rotates as the main motion, supplemented by the feed motion of the worktable or the milling head, and the workpiece can obtain the required processing surface. Due to the multi-edge intermittent cutting, the productivity of the milling machine is high. In simple terms, a milling machine can be a machine tool for milling, drilling, and boring workpieces.

1. Development History

The milling machine was originally a horizontal milling machine created by American E. Whitney in 1818. To mill the spiral grooves of twist drills, American J.R. Brown created the first universal milling machine in 1862, which was the prototype of a lifting table milling machine. Around 1884, gantry milling machines appeared. In the 1920s, a semi-automatic milling machine appeared, and the worktable used a stop to complete the automatic conversion of "feed-fast" or "rapid-feed".

After 1950, milling machines developed rapidly in terms of control systems, and the application of digital control greatly improved the degree of automation of milling machines. Especially after the 1970s, the digital control system and automatic tool change system of the microprocessor were applied on the milling machine, which expanded the processing range of the milling machine and improved the processing accuracy and efficiency.

As the mechanization process continues to intensify, CNC programming has begun to be widely used in machine tool operations, which greatly frees up labor. CNC programming milling machines will gradually replace manual operations. The requirements for employees will also be higher and higher, and of course, the efficiency brought about will be higher and higher.

2. Main Classification

Distinguish by Layout Form And Scope of Application

● Lifting table milling machine: There are universal, horizontal and vertical, etc., mainly used for processing small and medium-sized parts, and the most widely used.

● Gantry milling machines: including Gantry milling and boring machines, planer milling machines, and double-column milling machines, all used for processing large parts.

● Single-column milling machine and single-arm milling machine: The horizontal milling head of the former can move along the column guide rail, and the worktable is fed longitudinally; the end milling head of the latter can move horizontally along the cantilever guide rail, and the cantilever can also adjust the height along the column guide rail. Both are used to process large parts.

● Worktable non-lifting milling machine: There are two types of rectangular worktable and round worktables. It is a medium-sized milling machine between the lifting table milling machine and the gantry milling machine. The vertical movement is completed by the milling head lifting on the column.

● Meter milling machine: a small lifting table milling machine, used to process instruments and other small parts.

● Tool milling machine: It is used for mold and tool manufacturing. It is equipped with various accessories such as an end milling head, universal angle table, and plug. It can also perform drilling, boring, and slotting.

● Other milling machines: such as keyway milling machines, cam milling machines, crankshaft milling machines, roll journal milling machines and square ingot milling machines, etc., are special milling machines manufactured for processing corresponding workpieces.

According to Structure

● Desktop milling machine: a small milling machine used for milling small parts such as instruments and meters.

● Cantilever milling machine: a milling machine with a milling head mounted on a cantilever. The bed is arranged horizontally. The cantilever can generally move vertically along the column guide rail on one side of the bed, and the milling head moves along the cantilever guide rail.

● Ram milling machine: a milling machine with a spindle mounted on a ram.

● Gantry milling machine: The bed is arranged horizontally, and the columns and connecting beams on both sides of the milling machine constitute the portal frame. The milling head is installed on the beam and the column, and can move along the guide rail. Generally, the beam can move vertically along the column guide rail, and the worktable can move longitudinally along the bed guide rail for processing large pieces.

● Plane milling machine: a milling machine used for milling flat and forming surfaces.

● Profiling milling machine: a milling machine for profiling workpieces. Generally used for processing complex shape workpieces.

● Elevating table milling machine: a milling machine with an elevating table that can move vertically along the guide rail of the bed. The worktable and sliding saddle usually installed on the elevating table can move longitudinally and laterally, respectively.

● Radial arm milling machine: Radial arm milling machine can also be called turret milling machine, radial arm milling, universal milling, machine tool turret milling machine is a kind of light general metal cutting machine, with vertical and horizontal milling functions, can mill small and medium parts Planes, bevels, grooves, and splines, etc.

● Bed type milling machine: The worktable cannot be raised and lowered, and it can move longitudinally and horizontally along the bed guide rail, and the milling head or column can be moved vertically.

● Special milling machine: such as tool milling machine: a milling machine used for milling tool molds, with high machining accuracy and complex machining shapes.

According to The Control Method

Milling machines can be divided into profiling milling machines, program-controlled milling machines, and CNC milling machines.

3. Cutter Classification

It is used to process planes, steps, grooves, forming surfaces, and cut off workpieces on milling machines.

There Are Many Commonly Used Types of Milling Cutters According to Their Purposes:

● Cylindrical milling cutter: used for processing planes on horizontal milling machines. The cutter teeth are distributed on the circumference of the milling cutter. According to the tooth shape, they are divided into straight teeth and spiral teeth. According to the number of teeth, there are two types of coarse and fine teeth. The helical coarse-tooth milling cutter has a small number of teeth, high tooth strength, and large chip holding space, which is suitable for rough machining; fine-tooth milling cutters are suitable for fine machining.

● Face milling cutter: used for vertical milling machine, face milling machine or gantry milling machine, upper processing plane, there are cutter teeth on the end face and circumference, and there are also coarse and fine teeth. Its structure has three types: integral type, insert type, and indexable type.

● End milling cutter: used for processing grooves and step surfaces, etc. The cutter teeth are on the circumference and end surface, and cannot be fed along the axial direction when working. When the end mill has end teeth passing through the center, it can feed axially.

● Three-sided edge milling cutter: used for processing various grooves and stepped surfaces, with teeth on both sides and circumference.

● Angle milling cutter: It is used for milling grooves at a certain angle. There are two types of single-angle and double-angle cutters.

● Saw blade milling cutter: used to process deep grooves and cut off the workpiece, with more teeth on the circumference. To reduce friction during milling, there are 15'～1° secondary deflection angles on both sides of the cutter teeth. In addition, there are keyway milling cutters, dovetail milling cutters, T-slot milling cutters, and various forming milling cutters.

The Structure of The Milling Cutter is Divided Into 4 Types:

● Integral type: The cutter body and the cutter teeth are made into one body.

● Integral welding tooth type: The cutter teeth are made of cemented carbide or other wear-resistant tool materials and brazed on the cutter body.

● Inset type: The cutter teeth are fastened to the cutter body by mechanical clamping. This replaceable cutter tooth can be a cutter head of integral cutter material or a cutter head of welding cutter material. The milling cutter with the cutter head mounted on the cutter body for sharpening is called the internal sharpening type; the cutter head is individually sharpened on the fixture as the external sharpening type.

● Inset type: The cutter teeth are fastened to the cutter body by mechanical clamping. This replaceable cutter tooth can be a cutter head of integral cutter material or a cutter head of welding cutter material. The milling cutter with the cutter head mounted on the cutter body for sharpening is called the internal sharpening type; the cutter head is individually sharpened on the fixture as the external sharpening type.