Custom Automation for Sheet Metal Forming
Traditionally, sheet metal may be formed into various shapes by hammering the metal on various anvils. This labor intensive, physical process requires master craftsmen and is normally only suited to low volume production or prototype work. As products transition to higher volume, stamping dies are fabricated to greatly speed the process and reduce cost in quantity.
Applying automation to this labor intensive process has been difficult due to the wide variation in the size, shape, and weight of products that are manufactured. The different hammer patterns require a flexible holding system to allow nearly all of the sheet metal surface to be reached. Furthermore, the hammering can cause some metal to deform in process in an unpredictable way. This form is corrected in subsequent processes, but an automated hammering system must accommodate this changing shape.
The Fraunhofer CMI has collaborated with its customer to develop a new impact hammer system for the production of a wide variety of sheet metal shapes. Two impact hammers are incorporated into a work cell serviced by one loading robot. The work cell allows unattended processing, with the robot loading incoming metal blanks from material handling carts, and outputting processed parts on similar carts.
The hammers themselves use a high performance hydraulic ram system for the hammering action. The hammer can cycle in excess of 10 strikes per second, limited by the amount of positioning required between each strike. Interchangeable anvils can provide different hammering characteristics. The hammering force is programmable, as are all crucial process parameters such as the pattern and metal thickness. The operator needs to only select the appropriate program from a menu of choices. Manipulation of the sheet metal blank is accomplished with a robust, multi-axis positioning system using linear and rotary axes to provide full access to the metal surface for multiple shapes while withstanding the intense vibration and forces of the hammering operation. The work cell successfully processes the products while greatly reducing the required labor.
For more information about Fraunhofer CMI's capabilities in this field: