What is a Press Brake?
Press brakes are machine tools that bend metal. Typically sheet metal is used, but plate metal may also be used.
While brakes have many different parts, these are the most important:
- Ram – The tool which the punch is attached to and tonnage is exerted on, allowing the punch to bend the workpiece.
- Punch – The tool that “punches” the workpiece into the die which creates the bend.
- Workpiece – Whatever material the bend will be put into.
- Die – The tool that is creviced, which allows the workpiece to bend.
Types of Press Brakes
There are several types of press brakes, and they are named by the applying force used to bend the metal. Before 1950, mechanical press brakes were the most commonly used type of press brake. Since then, better hydraulics and computer controls has led to hydraulic brakes becoming the world’s standard.
Mechanical Press
An electric motor adds energy to a flywheel. The flywheel is then engaged by a clutch to power a crank mechanism that moves the ram vertically. The mechanical press has advantages of accuracy and speed over other types.
Hydraulic Press
The upper beam moves via two synchronized hydraulic cylinders on the C-frames. These press brakes are accurate, reliable, and use little energy. They are also safer, since ram motion can be stopped at any time, unlike mechanical press brakes.
Servo-Electric Press
Exerts tonnage on the ram by using a servo-motor to drive a ball, screw, or belt drive. These are typically used for lower tonnage applications.
Pneumatic Press
Tonnage on the ram is derived via air pressure. Like servo-electric, these brakes are used when higher tonnage is not needed.
Today, backgauges are commonly used for accurate positioning of metal to ensure the brake bends the metal in the right place. Backgauges can also be programmed to move between bends. This allows for press brake workers to quickly make complex parts without having to manually reset the backgauge.
The animation shows a programmed backgauge in work.
