Machine tools refer to power devices used to process work pieces and are important equipment in the manufacturing process of mechanical parts. Machine tools are generally used for forming, cutting, and joining other tools.
Machine Tool Overview
Machine tools are also called "work machines". They are machines for manufacturing various machines and processing equipment. They play a key role in the development of the entire machinery industry, so they are called the "mother of machinery."
Machine tool technology includes abrasives, casting manufacturing, transmission, electrical equipment, system integration, etc. On the contrary, machine tools are included in consumer electronics, automobile industry, machinery manufacturing, electrical equipment, railway locomotives, shipbuilding industry, defense industry, aerospace and other industries.
Define a machine tool
A machine tool is defined as a machine that pushes solid materials through a power source to form and process them by physical, chemical or other methods. Its definition can also be interpreted as a machine tool whose processing material is mainly metal workpiece.
Metal Cutting Machine Tool vs Metal Forming Machine Tool
Machine tools can be divided into metal cutting machine tools and metal forming machine tools according to their functions. The former uses debris, ash processing, discharge erosion, laser beam machining, and other methods to remove the part of the workpiece. The products include lathe (round processing). ), drill press (drilling), milling machine (plane processing), grinder (grinding), planer (plane cutting), electric discharge machine, etc.; the latter uses stamping to form the workpiece, and products include punching (pressing), shears Bed, forged bed, etc.
It is distinguished by the presence or absence of numerical control devices. Those without numerical control are called traditional machine tools; those who use a numerical signal operating system to control machine tool operators are called Numerical Control (NC) machine tools. Because most of the numerical control machine tools nowadays are performed by computers. Operational control, also known as Computer Numerical Control (CNC) machine tool, and the current production method is developing towards a PC-Based machine tool. After the NC machine tool, a comprehensive processing machine was developed. A single model is suitable for the same processing needs. Also, to meet the current production process, the processing needs of speed and quality are more or less diverse. The automatic feeding and chip removal system are further developed. , Tool storage exchange system, automatic workpiece change system combined with other related peripheral equipment, combined with a single machine or multiple machine tools of the same function or different function to form a Flexible Manufacturing Cell (FMC) or Flexible Manufacturing System (FMS), set the program, After a succession of automatic processing, the workpiece will become the required shape. It needs to go through repeated upper and lower molds and correction processes to achieve stable quality and improve processing efficiency.
Machine Tools are composed of two or more units, and these components have the same purpose on the same machine. But when it constitutes the machine tool structure, it must have the following characteristics:
Types of machine tools and processing methods
- The rigidity of the structure must be sufficient.
- Must be used for the operation.
- Must be in supplementary items.
- Must be used to remove the genus chips.
- Sufficient security must be maintained.
- Sufficient resistance to degeneration must be maintained (to ensure the accuracy of the workpiece size).
The machine tool is named according to the structure of its combined unit. Common machine tools are lathe, horizontal boring machine, sharper and planer, planning, milling machine, vertical Lathe, cylindrical grinder, floor-type milling & boring machine, bench drilling machine, multi-spindle drilling machine, moving crossbeam machining center, etc.
Machine tool components
The machine tool is composed of several individual components, and each component has its special function. These components include headstock, bed or base, machine column, worktable, saddle, machine tool, and foundation or channel, etc.
- Headstock: The headstock of the machine can drive and feed the cutting tool, or rotate the workpiece.
- Bed or base: It is a bed or base that supports other elements. On the bed, the base supports the head block, tailstock, moving plate and compound knife block, etc.
- Column: It has the function of guiding the head base; for large machines, bones are added to the machine column to strengthen the structure.
- Workbench: The workbench is used to support the workpiece. It is a bed with a saddle that can be moved on a horizontal plane.
Traditional vs. Non-traditional Processing
There are many ways to process materials into finished products in machinery factories. According to the principles of processing, they can be divided into traditional processing and non-traditional processing. The former can be said to be the traditional direct contact between the processed tool and the processed workpiece. The latter is applied to actual processing according to modern scientific and technological principles, and the tool does not directly contact the workpiece. No matter traditional processing or non-traditional processing can be divided into metal cutting processing and metal forming processing.
Traditional cutting processing is an operation method that uses wedge-shaped tools to remove the workpiece material, such as turning on a lathe, planing, drilling, boring, reaming, sawing, broaching, milling, grinding, and rolling. Tooth cutting, etc. The forming process is a method of forcing the workpiece material to be formed into the required product through various molds and heating, pressurizing, and other equipment, such as the shearing of shear, the blanking, and punching of the press, the turning forming, and the drawing. Leading or deep drawing forming, hot and cold forging, Orbital Forging, extrusion, roll forming, powder metallurgy. Casting is divided into general sand mold casting, metal dies casting (subdivided into gravity casting method, low-pressure casting method, and high-pressure casting method), squeeze casting, precision casting (subdivided into dewaxing casting, centrifugal (rotating) casting, adding Pressure dewaxing casting, vacuum casting, plaster mold casting, ceramic mold casting), etc.
Non-traditional cutting processing mostly uses mechanical methods-ultrasonic processing, ultrasonic vibration grinding processing, abrasive jet, water jet processing, etc., or electrochemical methods-Electrochemical Machinery (ECM), Electrochemical Grinding (EGG) or Electrical Discharge Machining (EDM), or thermoelectric type-Laser Beam Machining and Electron Beam Machining. In terms of forming processing, there are methods such as magnetic pulse forming, explosive forming, electroforming, and hydraulic forming.
Surface treatment technology
Surface treatment technology refers to the protection of the base material by modifying the surface of the material or coating a layer of other materials. Surface treatment includes surface treatment and surface coating.
Surface treatment includes: mechanical method (beading method, cutting, honing, sanding, fine grinding, grinding, super processing), metallurgical method (surface hardening, quenching, carburizing, nitriding, diffusion coating method), chemical method (Electrolytic polishing, pickling, chemical polishing, acid etching, and engraving).
The surface coating includes: skin coating (electroplating, electroless plating, hot-dip coating, spray coating, vacuum evaporation, cathodic sputtering), inorganic coating (anodic treatment, chemical conversion treatment, coloring, enamel treatment), organic coating (Painting, rubber lining, plastic lining).
Power source of machine tool
The power of the machine tool can be provided by an electric motor. Electric motors can be divided into DC motors and AC motors. Traditionally, DC motors have the advantages of large power output, quick and smooth acceleration and deceleration response, and low temperature. But DC motors have easily damaged parts such as brushes. Sparks generated during rectification may cause a fire, and the maximum rate is therefore limited. Fragile parts also increase the failure rate. No brushes are required for AC motors. In addition to the power and acceleration and deceleration response in recent years, the most advanced technology is that the linear motor directly drives the linear axis of the machine tool indirectly through a drive mechanism such as a screw or a rack and pinion.