Deep Drawing Press Machine

Deep Drawing Press Machine

We are one of the Deep Drawing Press Machine manufacturers. Deep drawing process & Deep drawing press & Double action deep drawing press & Triple action deep drawing press

Deep drawing is a secondary forming process in which in its simplest form a cylindrical shape or alike (for example a cone or frustum) is produced from a thin disc of sheet metal by subjecting it to a compressive force (while it is held between a die and blank holder) through a circular punch which mainly on the blank thickness as illustrated in Figure 1.

The deep drawing mechanism is a complicated process, particularly the different types of stresses on each region in the blank. To facilitate the understanding of the mechanism, the blank is divided into three regions X, Y, and Z. The outer annual region X is sandwiched between the die at its bottom part and the blank holder at its top part.

Region Y, the inner annular region is not in contact with either the punch or the die, and Z the central region of the blank is only in contact with the punch as illustrated in Figure 1(a). When the compressive force is applied to the punch, the draw proceeds the material in region X starts to draw progressively inwards towards the die profile under the effect of the applied tensile stress resulting in continuously decreasing the radii in this region which causes induced compressive hoop stress which causes an increase in the material thickness at the outer part of region X.

Deep Drawing Press Machine

A deep draw press is a type of metalworking press used to transform flat metal sheets into three-dimensional shapes. It is a versatile tool that can produce a wide range of products, including cooking pots, pans, automotive parts, and electrical enclosures.

How a Deep Draw Press Works:

  1. Blanking: A stamping press is used to cut out a flat blank from a sheet of metal. The blank size is slightly larger than the desired final shape to allow for metal flow during the drawing process.
  2. Heating: The blank may be heated to improve its formability and reduce the risk of cracking. Heating is particularly important for thicker materials or complex shapes.
  3. Loading: The blank is placed on the blank holder of the deep draw press. The blank holder firmly grips the blank around its edges, preventing it from wrinkling or buckling during the drawing process.
  4. Drawing: The punch, a tool with the desired shape of the final product, descends into the blank holder, forcing the blank into the desired shape. The blank flows over the punch, forming the desired three-dimensional shape.
  5. Trimming: Excess material around the edges of the drawn part is trimmed away using a trimming die. This ensures that the final part has a clean edge and meets the desired dimensions.

Types of Deep Draw Presses:

  1. Single-Action Deep Draw Presses: These presses use a single ram to perform both the drawing and trimming operations. They are relatively simple and inexpensive, but they are limited in the complexity of shapes they can produce.
  2. Double-Action Deep Draw Presses: These presses have two rams, one for drawing and one for trimming. This allows for more complex shapes to be produced, as the drawing ram can continue to draw the blank while the trimming ram trims the edges.
  3. Triple-Action Deep Draw Presses: These presses have three rams, one for drawing, one for trimming, and one for ejecting the finished part. They are used for producing the most complex shapes, such as those with undercut features or re-entrant angles.

Applications of Deep Draw Presses:

Deep draw presses are used in a wide variety of industries, including:

  • Automotive Industry: Producing car body panels, fenders, hoods, and other automotive components.
  • Appliance Industry: Manufacturing cooking pots, pans, sinks, and other appliance components.
  • Aerospace Industry: Creating aircraft components, such as fuel tanks, fuselage sections, and engine housings.
  • Electrical Industry: Producing electrical enclosures, housings, and components.
  • Construction Industry: Manufacturing architectural panels, roofing components, and ventilation ducts.

Benefits of Using Deep Draw Presses:

Deep draw presses offer several advantages over other metalforming methods, such as stamping and casting:

  • Versatility: Deep draw presses can produce a wide range of shapes, from simple cylinders to complex geometries.
  • Accuracy: Deep draw presses can achieve high levels of accuracy and consistency in the dimensions of the finished parts.
  • Efficiency: Deep draw presses can produce parts quickly and efficiently, making them a cost-effective manufacturing method.
  • Material Savings: Deep draw presses can produce parts with minimal waste of material.
  • Strength and Durability: Deep-drawn parts are generally stronger and more durable than those produced by other methods.

In conclusion, deep draw presses are versatile and powerful tools that play a crucial role in various industries. Their ability to produce complex shapes with high precision and efficiency makes them an essential part of modern manufacturing.

Holding the Pressure of a Deep Drawing Press Machine

Unless holding down pressure is applied, the induced hoop stress will cause the blank to fold causing wrinkling. When the material in region X passes over the die profile it is thinned by plastic bending under the effect of the tensile stress. The net effect of the outer part of region X is an increase in the thickness of the material.

Regarding the material in region Y, it can be readily seen that it is subjected to bending and sliding over the die profile; part to stretching in tension in the clearance region, part to stretching between the die and punch in the clearance zone, and part to bending and sliding over the punch profile. Finally, zone Z is subjected only to stretching and sliding over the punch head. The above mechanism can be summarized in accordance with the above division of the blank and the type of stresses to which each region is subjected to:

Various parts of region X may go through some or all of the processes i, ii, and iii; while parts of region Y may go through some or all of processes ii, iii, and iv; finally, parts of region Z may go through some or all of processes iii, iv and v. It should be noted that process i causes thickening of the blank whereas processes ii, iii, iv and v causes it’s thinning.

Figure 2 shows the variation of the thickness along the wall of a drawn cylindrical cup for a flat-headed punch on the right-hand side In hemispherical punches, making allowance for bending over the punch profile radius is not essential, whereas in the more general case of drawing with a flat-headed punch, making allowance for bending over the die and punch profiles, has not yet been solved.

The punch load at any phase of the drawing is determined by the forming region. If the blank is held rigidly at the die to prevent radial drawing the process becomes one of pure stretch-forming. Extensive and detailed experimental and theoretical investigations of cup draws have been carried out by different researchers, aiming at reducing the different defects in the process and improving the quality of the produced parts

Materials used with the Deep Drawing Press Machine

Materials used with a Deep Drawing Press Machine
Materials used with a Deep Drawing Press Machine

The specimens were circular discs of 180 mm diameter and 0.42 mm thickness made from carbon steel with the following w.t. percentages: 0.22% C and 0.5%Mn and the remainder is Fe. They were annealed before being used. Their mechanical behavior in the annealed condition is shown in Figure 3.

The deep drawing tests were carried out using the die shown in Figure 4 which was designed and manufactured for this purpose. It consists of the following main parts: the upper and lower platens in line. They were made of galvanized steel, sleeves, and blank and die holders which were all made from galvanized carbon steel. Compression springs and the punch and die which were made of X12M die steel of the chemical composition shown in Table 1.

The Punch and the Die of a Deep Drawing Press Machine

The punch and die were heat treated in accordance with the heat treatment recommended by the suppliers and the obtained hardness, as measured by Rockwell Hardness, is RC 67. All the punches and dies which were used for investigating the different parameters in this paper i.e. radial clearance
percentages defined as, the radial clearance between punch and die / the blank thickness = C / to, where C is the clearance and to is the original thickness of the blank, punch and die profile radii were all made of the same material and heat treated to RC 67 and their diameters were measured using the Tool Makers traveling microscope and their profile radii using shadowgraph at magnification X20.

The values of the used radial clearance percentages are shown in Table 2. Five punches and five dies with different profile radii were machined and ground under the same cutting conditions. Their dimensions are shown in Tables 3 and 4 respectively.

Normally, two types of blank-holding down pressure are commonly used: clearance blank-holding and pressure blank-holding; the object in each case is to prevent wrinkling of the blank during radial drawing, but with the minimum of interference with free drawing. In the early work of reference, on mild steel blanks it was shown that with clearance blank-holding, an initial clearance of 5 percent was sufficient for this purpose.

The medium pressure

Hydraulic Deep Drawing Press Machine
Hydraulic Deep Drawing Press Machine

With pressure blank-holding, the medium pressure necessary to prevent
wrinkling was 400 psi of blank contact area and clearance of 0.002 when clearance blank–holding was used. The same was adopted in this research work. It was also found that increasing the force beyond this amount had little effect on the maximum punch load or on the final thickness in the base or the profile radius of the produced cups, though the walls were thinner with the higher loads.

The drawing ratio is defined as the ratio of the blank diameter to the throat diameter of the die. It was found that for any given drawing conditions the punch load increases with blank diameter in an approximately linear manner, over the whole of the useful range with a slight tendency to drop near the limiting drawing ratio. It is worth mentioning in this respect that one should differentiate between the drawing ratio which is a geometrical parameter and the limiting drawing ratio which is a material property

Radial Clearance in a Deep Drawing Press Machine

The radial clearance between punch and die throat may affect the drawing process directly by controlling the freedom of the walls either to thicken or to taper and pucker. It can be seen from Figure 4b that the maximum drawing force is greatly influenced by the radial clearance particularly when its value is less than the blank thickness i.e. the case known as the ironing condition where it increased more than three folds. As the clearance increases above the blank thickness, it becomes less effective until it reaches a constant value e.g. it can be seen that.

The best radial clearance percentage for the steel used material was the difference in the maximum drawing force all C / to % above 100 % within the tested range does not exceed 10 %, however, at 130 % the produced cups have the least wrinkling and ears height. This is in agreement with the results reported in reference [10] for mild steel. Hence a net radial clearance of about 30 percent is suitable for general purposes, with free drawing and a reduction of 50 percent, and this has the sanction of practical experience.

Deep Drawing Press Machine Types

Deep Drawing Press Machine Types
Deep Drawing Press Machine Types

However, increasing it beyond this value may allow a bell mouth to persist near the rim of the cup, which would be practically objectionable if the deep-drawn products are required to undergo a re-drawing operation. A more important feature than the drawing force is the local strain in the blank, which may lead to local necking and finally to cracks and fractures. Radial stresses tend to thicken the blank at its rim while bending and sliding over the die profile and the punch head tends to thin it.

The most serious thinning arises from the stretching over the punch head and particularly between the punch head and the die to reduce the thinning as much as possible it is required to maintain high frictional condition on the punch while maintaining low friction everywhere else similar to mandrill drawing.