Process For The Non-Cutting Production Of Sheet Steel Containers

What is this patent about?

'437 is related to the field of metal forming, specifically the process of deep drawing and ironing cup-shaped blanks to reduce their diameter and wall thickness. This is commonly used in manufacturing processes to create containers or other hollow metal parts with precise dimensions. The background involves multiple stages of drawing and ironing, each requiring significant force and generating substantial heat due to friction between the metal and the forming dies.

The underlying idea behind '437 is to improve the cooling efficiency during the ironing process by directly applying a fluid medium to the working zone where the metal is being deformed. Instead of relying on overall cooling of the die or the blank, the invention focuses on localized cooling to prevent overheating, reduce friction, and improve the quality of the finished part.

The claims of '437 focus on a method where a cup-shaped blank is drawn through a series of dies, each with a punch that is slightly smaller than the inside diameter of the blank. This creates an annular gap between the punch and the blank's inner surface. The key is the introduction of a fluid coolant into this annular gap, directly targeting the working zone where the diameter and wall thickness are being reduced.

In practice, the cup-shaped blank is progressively pushed through a series of dies, each incrementally reducing the diameter and wall thickness. The fluid medium, circulating within the annular gap, acts as a localized heat sink, drawing heat away from the deforming metal. This precise cooling allows for higher forming speeds and tighter tolerances, while also minimizing the risk of material failure due to excessive heat buildup.

This approach differs from traditional methods that rely on cooling the entire die or using lubricants that may not effectively reach the critical working zone. By directly injecting the coolant into the annular gap, the invention ensures that the cooling effect is concentrated precisely where it is needed most, leading to improved process control and potentially enabling the use of more aggressive forming parameters.