The manufacture of parts is a time-consuming process, which includes a huge number of different types of processing. As a rule, it begins with the preparation of route technology and the implementation of the drawing. This documentation contains all the necessary data for the manufacture of the part. Machining is a rather important stage, which includes a huge number of different operations. Let's consider them in more detail.
Material
Depending on the required part, a metal material is also chosen. Upon subsequent processing, a finished product is obtained. In other words, metal material is a workpiece. It can be of several types: stamping, forging, rolling, cermets. Each type of blank has a different manufacturing method. If, for example, for forging, small-scale production uses forging hammers, then to obtain cermet material - pressing metal powders in molds under a pressure of 100-600 MPa.
Flat and cylindrical surfaces
Flat surfaces are processed by milling, planing, drawing. As a rule, such blanks include sheet metal and cermets.
Planing is carried out on transverse and longitudinal planing machines. When processing at the first, the main movement is carried out by the cutter, and the feed movement is the table of the machine. On the longitudinal planing - the opposite is true. In addition, such a machining is considered unproductive, since it has too low a cutting speed. The working tool loses a lot of time on the return idling. The advantages of this processing is the provision of straightness and proportionality.
Milling
Milling is considered one of the most highly productive methods of processing both flat and cylindrical surfaces . This is because it is carried out simultaneously by several teeth of the cutter. The machining can be carried out in a sequential, parallel, series-parallel and continuous manner. By milling, it is possible to treat surfaces with a roughness of Rz = 0.8 - 0.63 ฮผm and this treatment will be called thin.
Stretching
In this way, parts are processed in mass and large-scale production. In some cases, drawing can be replaced by grinding and chiselling. Such machining has a very high accuracy. Pulling can be performed both in the vertical direction and in the horizontal. Such processing is used for operations associated with increased accuracy, and the cutting tool works under conditions of huge loads, such as compression, bending, stretching.
For example, pulling is used when machining holes in a firearm, for cutting keyways and splines. As a cutting tool, broaches, both solid and prefabricated, are used. They are made of high speed and medium alloy tool steels.
Hole and Thread Processing
Machining parts can not do without such important tools as drills, countersinks, taps, reamers. In order to drill a hole of the required diameter, it is necessary to calculate the cutting mode for this process. As a rule, the hole is drilled to the required diameter, taking into account the allowance for subsequent processing. In order to ensure the best accuracy, a scan is used, and for a semi-finishing processing, the use of a vertical drill is possible.
Machining of parts can also be done using a tap. This tool is designed for threading existing holes. There are taps for blind and through holes. For cutting external threads using cutters and dies. Before using them, it is necessary to grind the workpiece a little. In order to create a high-quality and effective approach of the cutting tool, before the start of the operation, the facet is removed from the end of the product. It should have the same height as the thread profile.
Mechanical processing of metal parts and thread processing in rare cases is carried out using screw-cutting heads. They are mounted in pins with a shank. It can have prismatic, radial or round combs. They do not come into contact with the threaded thread during the reverse stroke, since at the end of the process they automatically diverge.
Metal machining on machine tools and lines is studied at many colleges and universities. The specialty has a code 36-01-54 and is divided into the following areas: milling machine operator, turner, grinder, metalworker and machine tool controller, automatic (AL) and semi-automatic lines operator. Since modern technology does not stand still, it is very important to study the mechanical processing of metals on CNC machines and AL.
Such equipment greatly facilitates the work of operators. Their main task is to control, adjust and load-unload parts and blanks. Automatic lines perform all operations using special computer programs and practically do not require operator intervention. The use of AL can significantly reduce the cost of processing and manufacturing time of parts.