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Drawing tools

Products drawing

1. Drawing is the process of processing of metals by pressure, in which the workpiece is pulled through the hole of the die, the dimensions of which are smaller than the cross section of the initial billet. In the result of the drawing is obtained a product with a constant cross-section throughout its length.

The essence of the drawing process consists in the following. The rod 1 with the initial section F1 sharpened front end which is passed through the point of the die 2. To the front end of the rod emerging from the die, apply the external force R,called the drawing force. Rod, passing through the point of the die is deformed and adopts the shape and dimensions of the die points. The final section F2прутка smaller than the original F1.


The basic methods of drawing of products:

1 – product; 2 – portage; 3 – mandrel; 4 – mouthpiece; 5 – drawing the bolt

2. When drawing lubricant metal and drawbench points reducing friction and the effort of drawing and the temperature in the deformation zone, prevents the adhesion of metal to the wires, and improves the surface quality of the product. In addition, the lubricant allows to increase the compression for the passage and drawing speed.

Used in the drawing the lubricant is separated into a solid (soap powder, graphite, paraffin), grease or semi-liquid (solid oils, greases, mineral oil mixed with soap and water, Petro-latoma, etc.) and liquid (aqueous emulsion of mineral oil and soap, etc.). Introduction to lubrication of small quantities of surface-active substances (sulphur, phosphorus, etc.) facilitates the process of deformation of the metal. These substances penetrate in the microcracks on the surface of the workpiece extend and create additional pushing efforts to facilitate the process of deformation under the influence of external forces.

The drawing process is carried out usually at room temperature. Released by deformation of the metal heat is removed by cooling of a continuous rod of emulsion, water or air. In the process of drawing metal nakladyvaya and acquires a fibrous structure (texture). This causes a change in the physical, chemical and especially mechanical properties of the metal.

The main ways of drawing, in addition to the, refer to the drawing of tubes without a mandrel to reduce the outer and inner diameters of the pipe and increase the length (the thickness of the tube wall does not change); the drawing of tubes on the mandrel to reduce the outer and inner diameters and wall thickness of the pipe; drawing the disk rotating portages to obtain complex profiles. In the latter case, the rotation of non-driven discs carried by the force of the drag due to friction forces.