Bending machines, also known as press brakes, are essential equipment in metal fabrication. Understanding how they work is crucial for operators, engineers, and anyone involved in sheet metal processing.
Basic Working Principle
A bending machine works by applying controlled force to a metal sheet placed between a punch (upper tool) and a die (lower tool). When the punch descends, it forces the metal into the die cavity, creating a precise bend. The bending process follows the principles of plastic deformation, where the metal is permanently shaped without breaking.
Key Components
- Hydraulic or Electric Drive System: Modern bending machines use either hydraulic cylinders or electric servo motors to generate bending force.
- Upper Beam (Ram) and Punch: The upper beam holds the punch tool and provides the downward force.
- Lower Beam and Die: The lower beam holds the V-die or other die shapes.
- Back Gauge System: Positions the sheet metal for accurate bend location.
- CNC Control System: Manages all machine functions including ram position, bending force, and back gauge positioning.
- Crowning System: Compensates for bed deflection to ensure uniform bend angles across the entire length.
Bending Methods
Air Bending: The most common method where the punch doesn't touch the bottom of the die. This method requires less force and is more flexible for different angles.
Bottoming: The punch presses the metal to the bottom of the die, requiring more force but producing more accurate angles.
Coining: The most precise method where extreme pressure completely forms the metal into the die shape, virtually eliminating springback.
Operating Sequence
- Select or program the bending sequence in the CNC controller
- Install appropriate punch and die tools
- Set material parameters (thickness, type, grain direction)
- Position the sheet against the back gauge
- Activate the bending cycle
- Machine automatically performs the bend with programmed parameters
- Reposition for next bend if required
Safety Features
Modern bending machines incorporate multiple safety systems including light curtains, laser guards, two-hand controls, and emergency stop buttons to ensure operator safety.
Conclusion
Understanding how bending machines work enables better operation, maintenance, and troubleshooting. At Rucheng Technology, we manufacture advanced bending machines with intuitive controls and reliable performance for all your metal forming needs.