FabShop Magazine - March 2012 - 15

››› PREss BRaKE RounduP
Simpson continues by saying that as the machine becomes more precise with better part development through engineering, welding gaps are reduced or many times eliminated by using new techniques in design. The type of complexity in these designs, however, requires a good machine to handle this type of forming. The TruBend 5000 answers the call with large open heights, programmable axes to eliminate multiple setups and precision tooling. Job shops that do smaller lot sizes of highcomplexity parts benefit greatly when using the Trumpf TruBend 5000, and especially so due to the automatically controlled bending (ACB) that facilitates high output with a high range of parts. It’s equipped with as many as eight angle sensors, and it’s possible to use up to three sensors at one time to control left, right and center angles. It can process shortleg lengths and has three-point angle feedback for long profiles. “The ACB Easy is an extension of the ACB system, but is wireless and allows quicker tool changeover using magnetic mechanisms rather than traditional screws,” Simpson explains. “Less setup equals more productivity.” Another new productivity enhancer that picks up the pace for the TruBend 5000 is its Operator Controlled Bending (OCB), which allows an operator to calculate left, right and center angle corrections through the use of a digital protractor and wireless connection to import the values into the control automatically. “This eliminates the need to walk back and forth to the control to enter these values and also makes sure the values are being entered correctly by importing them directly,” says Simpson. The TruBend 5000 series features bending lengths from 1,275 mm to 4,420 mm. Additionally, a variety of back-gauge systems are available for varying part geometries and levels of complexity. The typical two-axes back gauge can be upgraded all the way up to six axes where the back-gauge finger can be set independently. bystronic Xpert No one will argue that most high-end press brakes are accurate and repeatable machines. They can quickly move to a target position, reset that position and retract back up. But that doesn’t necessarily give a perfect bend each time. “The key is for the machine to recognize and account for variations in material,” says John Kemp, applications/training manager at Bystronic Inc. “Variations in tensile strength and thickness affect how much pressure a machine has to use and how it affects the machine when it makes a bend.” The Xpert minimizes adverse affects by measuring the pressure during the bend cycle, and it does it at a rate of every two milliseconds using sensors in its hydraulic system. For example, if an operator calculates that he’s going to use 50 tons of pressure on a particular bend, during the operation the machine’s control software might discover that the material is thicker or the tensile strength is a bit different, therefore, it will adjust the tonnage. “If the machine doesn’t compensate for the change in machine deflection caused by the change in pressure, you’re left with angle deviation as a result,” Kemp explains. “During the bend cycle, the Xpert’s dynamic crowning system is measuring those pressures. It’s measuring where the bend is taking place on the bed, and it’s also taking into account how long the part is because that affects how the upper and lower beams deflect when you apply a load to it.”

The Bystronic Xpert press brake minimizes adverse affects by measuring the pressure during the bend cycle every 2 milliseconds.

FabShop Magazine - March 2012

Table of Contents for the Digital Edition of FabShop Magazine - March 2012