Integrated leveling for punch machines
Trumpf has integrated a new flattening concept into its punch/laser combination machines.
Farmington, CT – Trumpf Inc. has integrated a new flattening concept into its punch/laser combination machines. This integration makes it possible to punch a large number of holes in thin sheet metal without distorting the panel.
In the standard punching process, the punch draws material into the hole as it penetrates the sheet, creating compressive stress. As the punch is withdrawn, tensile stress is produced. These forces can cause deformation in the material, especially when processing low-gauge sheet metal with many holes. With integrated flattening, opposing stresses are introduced to keep the sheet metal panels flat, thereby eliminating the additional step to even out the material. The function is available on the TruPunch 5000 punching machine and the TruMatic 7000 punch laser combination machine.
To help the sheet metal maintain its flatness, the convex die works in tandem with a stripper featuring a recess and special coating. The convex die presses the sheet metal against the stripper from underneath which overbends the material. The concave stripper counteracts by pressing the material raised by the convex die back downward at the edge of the die. The overbending creates counter-stresses, which offset the compressive and tensile stresses caused by the punching process. In this way, the sheet metal is flat when it leaves the machine.