Drawing is analysed with the working principle of wire drawing die
Our country is wire producer, production in the world. Wire is widely used in communications, construction, electricity and other departments. In the wire rod production, drawing machining is the most commonly used one kind of way. Scope of application is very extensive drawing processing, mainly used in drawing rod, wire and other linear materials. Drawing production can solve the problem of turning methods are difficult to machining wire, its machining precision is high, and its processing speed, low degree of waste of blank, high utilization rate. Wire drawing die is not only a kind of very important of various kinds of metal wire drawing easy attrition of mould, the cost of the wire drawing die accounted for more than 50% the cost of the drawing. Currently widely used drawing die with alloy steel, cemented carbide and diamond die, all kinds of wire drawing die in use process has its own advantages and disadvantages. Now work principle of wire drawing die and common wire-drawing die material, wire drawing die wear classification and the influence factors of drawing process for the following.
The basic structure of drawing die
The basic structure of wire drawing die, drawing die is the main work area inner hole, inner hole structure according to the nature of work can be divided into the entrance area,
, lubrication area, sizing area, export area of five interval and follow the theory of smooth transition, namely drawing die hole
In the border districts into smaller rounded transition. By drawing wire from the entrance into the wire drawing die, the drawing force I
By drawing die and friction in the wire drawing die cone in the work place, drawn out from the exit and get smaller wires.
Drawing die regional size selection
(1) entrance area
The entrance of the drawing die hole Angle is one of the important parameters, must ensure that the points of contact wire into the mould is happening
In wire drawing die reduction zone on the same level position, and is advantageous to the wire. Wire drawing die entrance area raised to lubrication area and the smooth appearance of deformation area, enables the lubricant to reach the surface of the wire drawing die work.
(2) lubrication area
Lubricating the role lies in the storage of lubricant, and its input workspace. Depending on the lubricant viscosity, wire diameter
Different and the length of the lubrication, lubrication area cone Angle is different, for the liquid lubricant can be smoothly into the workspace, lubrication
Area Angle generally choose larger values. Too small lubricant should not enter, and lubricant flows, not even form the wedge block,
Lubrication area cone Angle is too large is not easy to form the fluid dynamic pressure effect. Lubrication area length length will also affect the lubrication effect, in general, no matter what kind of lubrication, lubrication area, the longer the better the lubrication effect.
(3) the workspace
The workspace is wire has the area of plastic deformation and its size parameters have the workspace work cone Angle a and cone length of h2. workThe parameters of the taper Angle is a wire drawing die, work area the size of the cone Angle of a role in drawing die pressure and the size of the holeThe distribution, the size of the drawing stress and mechanical properties was drawing wire quality plays a decisive role.
The lowest work cone Angle corresponding to the drawing stress varies with the drawing environment, there is a best work cone Angle range. When drawing
It is difficult to ensure that the axis of the wire rod and wire drawing die hole axis concentric, combined with the drawing before when drawing die hole caused by excessive wear into the inner hole of wire diameter increases, both will cause a wire in the deformation area outside, so the work zone length should be greater than the actual deformation zone length.
(4) sizing area
Sizing area according to wire the allowed tolerance and wire diameter size in the drawing to determine the elastic deformation, and both the service life of the mold, usually choose wire minus tolerance size.
Determine the sizing zone length shall meet the following requirements: enough resistance to wear, when drawing the energy consumption and reduce the probability of tensile wire. Although sizing area for too long can improve the service life of drawing die, but at the same time also can cause the increase of friction, heat and energy consumption, and easy cause wire diameter cut or broken wire. Such as sizing area are too short, can cause shaking wire when drawing and produce corrugated shape, also can make the wire drawing die hole quickly wear out-of-tolerance lead to size. In general, the drawing wire diameter, the greater the the sizing zone length short accordingly.
(5) export zones
Export zones formed in the wire drawing die 90 degree Angle. To facilitate the export of specific wide this point of view, so as to make the wire drawing die can many times to restore to its original size without the need for reprocessing. Export zones often is not considered important. But if drawing die does not export zones, sizing with trailing edge will crack or flake, lead to damage of wire drawing die.