Press Brake Machine

A press brake machine is a piece of manufacturing equipment that is used to bend sheet metal. It forms predetermined bends by clamping the workpiece between a matching punch and die. The material is placed over a V-shaped die and pressed into from above by a punch. 

A press brake is a machine used to make repeatable, precise, and reliable bends in metal sheets. Typically, two C-frames form the sides of the press brake, connected to a table at the bottom and on a movable beam at the top. The bottom tool is mounted on the table, with the top tool mounted on the upper beam. Brakes are classified according to tonnage and bed length. They can be fitted with various types of punches and dies to control the bend of the sheet. Most now come fitted with an automated backgauge that aids in positioning and holding the sheet, greatly increasing repeatability.

A press brake machinery is typically narrow and long so that large pieces of sheet metal can be bent by it. A press brake bends sheet metal by lowering a punch onto sheet metal that has been positioned on top of a die. The metal may be bent several times by a press brake machine until the desired form has been achieved. These machines can bend simple and complex parts, and they are used in a variety of industries ranging from automotive and aircraft to housing and cabinets. BLMA is China's famous press brake manufacturers and supplier, providing professional sheet metal cutting knowledge and high-quality CNC press brake for sale and NC hydraulic press brake. 

The Principle of Press Brake Machine

The hydraulic press brake bending machine includes a support, a workbench, and a clamping plate. The workbench is placed on the support. The workbench is composed of a base and a pressure plate. The base is connected to the clamping plate through a hinge. The base is composed of a housing, a coil, and a cover. The coil is placed in the recess of the seat shell, and the top of the recess is covered with a cover plate.

When in use, the wire is energized to the coil, and the gravitational force is generated on the pressing plate after being energized, so as to realize the clamping of the thin plate between the pressing plate and the base. Due to the electromagnetic clamping, the pressing plate can be made into a variety of workpiece requirements, and the workpiece with sidewalls can be processed. The bending machine can meet the needs of various workpieces by changing the mold of the bending machine. 

Types of Sheet Metal Press Brake

● Mechanical press brake machine

The mechanical press brake has a flywheel that is powered by an electric motor. A mechanically driven has a fixed tonnage and exerts more force at the bottom of its stroke as compared to the halfway point. They normally are capable of 150% of rated tonnage at the bottom of the stroke. The two major benefits of mechanical press brake are speed and accuracy.

● Hydraulic press brake machine

The hydraulic press brake functions through two synchronized hydraulic cylinders on the C frames, in order to move the upper beam. They are ideal for working with large, inexpensive materials that do not require high-precision bends. The hydraulic press brake for sale is basically high speed, compact machines that are more precise and use less power. 

● NC press brake machine

The NC hydraulic press brake machine uses the NC (numerical control) system. In the NC system, digital control generally means that when the system is produced, the manufacturer has programmed the program, and the purchaser cannot modify the programmed program.

● CNC press brake machine

The CNC press brake for sale uses the CNC (computer numerical control) system. In the CNC system, computer numerical control means that the purchaser can edit the program according to the actual operational requirements before bending, and can make any modifications to the program. Computer numerical control systems are extremely convenient compared to digital control systems.

The Main Parts of Press Brake Machinery

Usually, the press brake machine tool is composed of 4 parts: mechanical part, electrical part, hydraulic part, CNC/NC controller

1. Workbench part: controlled by the button box, the motor drives the stopper to move back and forth, and the moving distance is controlled by the numerical control system. The minimum reading is 0.01 mm (the front and rear positions have travel switch limits)

2. Slider part: hydraulic transmission is adopted, and the slider part is composed of a slider, an oil cylinder, and a fine adjustment structure of a mechanical stopper. The left and right oil cylinders are fixed on the frame, the piston (rod) drives the slider to move up and down through hydraulic pressure, and the mechanical stop is controlled by the numerical control system to adjust the value.

3. Stopper mechanism: The stopper is driven by a motor, and the two screw rods are driven to move synchronously through a chain operation. The CNC system controls the size of the stopper.

4. Synchronization system: The machine consists of a mechanical synchronization mechanism composed of torsion shafts, swing arms, joint bearings, etc., with a simple structure, stable and reliable performance, and high synchronization accuracy. The mechanical stop is adjusted by the motor, and the numerical control system controls the value.

5. Synchronous servo valve: The servo valve is usually installed on the top of the cylinder. The output flow of the servo valve is mainly controlled by the DNC and the servo amplifier. These output flows mainly to control the slider speed during the entire stroke. The servo motor runs faster, the bending speed becomes slower, and the slider moves from the bottom dead center to the top dead center.

6. Motor: Use a higher performance servo motor.

7. Oil pump: The high-pressure gear pump is usually connected to the main motor.

8. Hydraulic oil tank: Usually the hydraulic oil tank is welded inside the machine, with a built-in oil filter, and an external motor, oil pump, high-pressure valve, control valve, and electronic system.

9. Oil filter: The oil filter accuracy of the general oil filter is 10 microns, and the maximum pressure is 400 bar. If the filter is blocked or the hydraulic oil is replaced, the filter element should be replaced.

10. Filling valve: The filling valve is located on the top of the cylinder. When the slider moves quickly, the oil in the oil tank flows into the oil cylinder through the filling valve. When bending, the filling valve is closed.

11. Protection system: DNC controls the protection of the entire journey. From the beginning of the machine tool operation, DNC monitors the time and stroke of the hydraulic oil during the entire stroke. This can also be referred to as hydraulic oil leakage monitoring.

1. Useful for a wider variety of applications

2. Can handle thicker materials

3. Better for large, thin sheets

4. Can be operated by just one person

5. Faster and more efficient for thinner metals

6. Reduction of manual handling and injury risk

7. Tooling can easily be swapped out for different tooling tasks

8. Better at bending highly polished, sensitive, or coated materials

The Applications of Press Brake Machine

The sheet metal press brakes are used to bend and fold metal by pressing it into a die. These presses are designed for both specialized sheet metal work and continuous production applications. They can handle tough industrial production jobs. Press brake machines are widely used in energy, transportation, automobile, machinery, metallurgy, shipbuilding, aviation, military, agricultural machinery, petroleum machinery, power generation industries.