The blanks of pipeline parts and equipment components obtained by forging, casting, rolling, in the vast majority, do not have the dimensional accuracy and surface quality required for their installation in various equipment. The final operation in converting the workpiece into a part is metal cutting.
Metal cutting is a technological process for the production of machine parts and equipment, which consists in cutting off with a cutting tool from the surface of the workpiece a layer of material in the form of chips to obtain a given geometric shape, accuracy and surface roughness of the part. Rolled products of various profiles, casting, forgings and stamping are used as blanks for future equipment parts.
The ring blanks plant performs turning, turning and boring, drilling and milling works.
To ensure control over the quality of machining for the conditions of single and small-scale production, the enterprise uses measuring instruments - calipers, depth gauges, protractors, micrometers, profilometers and other measuring devices.
For the manufacture of parts with specified geometric parameters, metal turning is used, which makes it possible to obtain a surface in compliance with the requirements for the geometric dimensions and shape of parts, as well as the degree of surface roughness and the accuracy of their relative position.
The technology of metal turning involves the use of special machines and cutting tools (cutters, drills, reamers, etc.), by means of which a layer of metal of the required size is removed from the part.
The main types of turning works:
processing of external cylindrical and conical surfaces;
face and shoulder machining;
grooving, parting off the workpiece;
machining of internal cylindrical and conical surfaces;
processing of shaped surfaces.
Turning and carousel metal processing.
For the processing of steel workpieces, which differ in impressive diameter and weight, but have a small height, lathes and carousels are used. Among the lathes of the boring-and-carousel group, the enterprise uses one- and two-column lathes. The former are equipped with faceplates with a diameter of up to 1300 mm for working with workpieces with a diameter of up to 1600 mm. On two-column machines, faceplates with a diameter of up to 2800 mm are installed to work with workpieces with a diameter of up to 3500 mm.
The main types of turning - carousel works:
production of cylindrical blanks;
milling tapered parts;
End trimming and trimming.
Lathes and boring machines, due to the design features, are distinguished by reliability, high safety, ease of maintenance and operation. The use of vertical lathes in the performance of work allows:
to obtain high precision and quality of manufactured parts;
provide serial and custom production;
reduce the number of scrap to a minimum;
reduce material consumption;
Drilling processing is carried out on special drilling machines, where the workpiece is rigidly fixed, and the cutting tool rotates and simultaneously moves translationally along the axis of the hole drilled in the workpiece.
The enterprise uses vertical drilling and radial drilling machines. Vertical drilling machines are used to drill holes in small workpieces, which are moved along the table during the adjustment process so that the axis of the drill and the axis of the future hole coincide. For work with heavy and large-sized workpieces, radial drilling machines are used. On them, the workpiece is immediately rigidly fixed on the table, and the machine spindle is set in the desired position. Rotary tables of various diameters are used to position the workpiece.
Basic types of drilling:
drilling cylindrical holes;
reaming cylindrical holes (increasing the diameter).
To combat heating, cooling is used with the help of cooling emulsions or cutting fluids (coolant). When drilling on machines, the fluid supply is organized directly to the place of drilling.
Milling metal processing.
Milling is carried out on vertical milling machines using various milling tools that are fixed in the chuck. Rotational force is transmitted to the chuck by means of the spindle, and the tool starts to rotate.
Milling is a productive and versatile technological method for machining workpieces by cutting. At the enterprise, planes, ledges, grooves of rectangular and profile sections, grooves, shaped surfaces, etc. are processed by milling.
For the processing of flat and shaped surfaces on milling machines, milling cutters are used - multi-flute (multi-edge) tools. Each cutter tooth is the simplest cutter.