CNC Press Brake in the Sheet Metal Fabrication process

What is Press Brake in Sheet Metal Fabrication?

Press Brake is an important process in any metal fabrication manufacturing. Press brake machine as the name suggests, is a pressing machine commonly used with a set of punch and dies to fabricate various types of sheet metal. It can be mechanical, pneumatic, hydraulic and servo-electric, but due to the advancement of hydraulics and control system, hydraulic press brake machines are currently the most opted for in the sheet metal industry.  

The basic parameters that governs a press brake machine are the force or tonnage and its working length. The machine’s working height, stroke length, distance to the back-gauge and crowning are the additional control parameters. Back in the days prior to the development of complex control systems, these parameters required an experienced and highly skilled operator to manually set and tune based on the product requirements. 

Why use a Computer-Numerical-Control (CNC) Press Brake in metal fabrication? 

1. High Flexibility, Low Setup Time – On top of its ability to automate and integrate with advanced robotic bending system, CNC press brake machines offer high flexibility with low setup times. Taking advantage of its immaculate control systems of the back-gauge distance, bend angle and stroke length, the control systems can be used to register and record the type of bends and its required setup parameters, enabling the setup of multiple bends using the same machine. Essentially a product be formed from a flat sheet metal to its final shape just from a single setup.  
2. Advanced Crowning System – Greater Consistency and Repeatability – Also known as the ‘kayak or canoe effect’, this is a condition that commonly occurs in high-tonnage press brake applications. The term ‘kayak’ refers to the deflection of the beams and table during the press sequence. Crowning is a fine-tuning process required to offset and equally distribute the forces of the press brake. Instead of using shims or grinding the bar to manually offset the deflection, the system compensates this effect by measuring the deflection and generating the opposite forces or “curve” necessary to ensure that the ram and table are parallel during bending. This allows for a consistent bend angle along the products bend line. What was previously an intricate and time-consuming process, are now simplified allowing for greater consistency and accuracy.