Press brakes are used to make bends in thick heavy sheets and to make complex bends in thin materials. There are two types of press brakes: mechanical and hydraulic. Since a large amount of power is required to bend the sheets or plates, the hydraulic presses are usually more appropriate for each job.
In order to fully understand the operation of a hydraulic press brake, you need to know how it works. Since hydraulic press brakes are made up of a number of components, keeping track of them all can be difficult. So, here is a basic list of some of the most prominent components.
1. Hydraulic fluid – Hydraulic fluid is transmitted through various parts of the machine. High pressure is exerted on hydraulic fluid by the hydraulic pump, thus creating highly energized fluid. This fluid then travels to the cylinders (actuators) where it delivers its stock of large amounts of energy to the piston, which operates the bending tools.
2. Hydraulic pump – The hydraulic pump actually produces the power that energizes the hydraulic fluid and transmits it through the machine to carry out the pressing operations.
If a pump has the rating of say 5,000 psi, it can maintain the flow of liquid against loads of 5,000 psi or it can apply that much pressure. The power density of hydraulic motors is ten times that of electric motors by volume.
The hydraulic pump is operated by an electric motor or an engine connected by gears, belts, or flexible couplings. It can be a gear pump, vane pump, axial piston pump, or radial piston pump. The hydraulic pump is the "generator" side of the whole hydraulic press brake system.
3. Actuator – The power contained in the hydraulic fluid is delivered to the actuator, which carries out the pressing operation. There are various types of actuators, but the one used in hydraulic press brake is the hydraulic cylinder.
The hydraulic cylinder is comprised of a cylinder barrel and a reciprocating piston. A large amount of energy contained in the hydraulic fluid is transmitted to the piston to carry out the linear work of pressing the metal sheets.
4. Control valves – The control valves direct the hydraulic fluid to the desired actuators. They control the amount of fluid and energy that is transmitted to the actuator. If there are multiple actuators, control valves distribute the fluid evenly among them as per the requirements of the operation.