FOCUS ON DEEP DRAWING
Deep-drawn parts ( image : KM RUSTFRI ).
Deep drawing presses and processes
A variety of deep-draw presses , each with different capabilities , are used to produce deepdrawn metal stampings . These can include , for example , ICOP ( Individually Cam Operated Presses ). These are transfer stamping presses where the part is transferred via transfer fingers as the part progresses through the forming process . Die components are installed in the press one station at a time .
Die-set transfer presses can also be used ( transfer stamping presses where the part is transferred via transfer fingers as the part progresses through the forming process ). Tooling components are attached to die plates so that the die can be installed in the press as one unit . Progressive die presses can also be used for deep-drawing operations ( these are stamping presses where the part is carried on the steel webbing as the part progresses through the forming process ). Other presses used for deep-drawing operations include servo-hydraulic presses and special purpose presses .
The deep-draw stamping process consists of many smaller individual processes . These can include the following :
■ Blanking : Blanking is the process of cutting the initial sheet coil stock into round or shaped flats required for deep drawing . The blanking processes is typically the first station in the press and involves a simple punch and die to cut out an initial metal blank that will then be deep drawn .
■ Drawing : Drawing is the process of forming the metal with a punch and die , and is the heart of the deep drawing process . Drawing is often accomplished with a progressively smaller series of dies that reduce the shape and increase the depth of the part .
Parts produced from progressive die operations .
■ Piercing : Piercing is the process of punching holes in the metal stock that are required for the finished part .
■ Trimming : In the trimming process , excess metal that is necessary to draw the part is cut away from the finished part .
Deep-drawing processes can be divided into three types : deep drawing with tools , deep drawing with active means and deep drawing with active energy . The automotive industry makes extensive use of deep-drawing presses , particularly for the production of a variety of components such as oil pans , intake manifolds , clutch housings , brake drums and many more . In the automotive industry , deep drawing is usually carried out using rigid tools .
A key benefit of deep drawing , compared to hydroforming , is the ability to perform multiple re-draws . Each draw can produce a 43 % reduction of the metal blank . Greater depths — up to 24 ” — can be achieved through multiple draws , which reduce the diameter and increase the height of the previously drawn shell . Deep drawing can be a multi-draw operation performed on a specially prepared metal blank . It can also be followed by secondary operations which range from custom fabrication to light assembly and finishing .
Deep drawing can produce highly aesthetic complex designs that other manufacturing techniques may not be able to create without using expensive secondary operations . It is also hugely versatile , capable of manufacturing items of any size and in a variety of shapes .
“ The process also offers tremendous value . With less material used in the process , there is less waste which reduces cost . Component quality can often be higher than with other processes and shows better repeatability in production batches , meaning higher volume and higher quality , all at a lower cost ,” concluded Stroud Metal Company Ltd . n
44 | ismr . net | ISMR June 2024