The press brake produces precise bending in the workpiece through force, molds, and specialized tools. Factors such as toolings, material characteristics, bending radius, and bending methods can all affect the accuracy of bending. According to machine design and specific application requirements, bending can be carried out through various driving forces, such as mechanical, pneumatic, hydraulic, or servo-electric. However, the main sources of bending power currently used are hydraulic, servo, and electric.
What Is Press Brake？
A press brake is a mechanical processing tool that is mainly used for sheet metal bending and forming.
The upper tool has usually named the punch, and the lower tool is called the die.
Press brake machines utilize matching upper and lower dies to process flat sheets, usually metal sheets, into workpieces of different shapes and angles by means of different pressure generators.
During the bending process, the top die is fixed horizontally between side uprights by clamps, and the bottom die is mounted on the worktable.
The workpiece is fixed on the lower die, and then the punch is driven by the press generator to bend the sheet metal.
When the punch descends, it forces the metal sheet to bend around the shape of the die. The final bending angle and radius depend on the die shape and parameter settings used.
The molds have different shapes, and the bending angles can be set in advance. Hence, different shapes and angles of metal sheets can be produced massively.
The main types of press brakes include hydraulic press brakes, mechanical press brakes, pneumatic press brakes, and electric press brakes.
What Is NC Press Brake？
NC press brake machines are early conventional bending machines.
NC press brakes use the torsion bar to connect the Y-axis on both sides of the ram (left Y1 and right Y2) and to drive hydraulic cylinders on the uprights.
Then, the ram can move up and down synchronously to bend metal sheets.
NC press brakes are very suitable for low-cost, easy-to-operate workpiece bending but not high-precision and high-volume production.
Since the NC press brake is mechanically synchronized, it cannot provide real-time feedback on the bending error and automatically adjust the error.
This can lead to poor bending accuracy.
In addition, the NC press brake drives cylinders up and down through the torsion shaft, and the long-term load can lead to the deformation of the torsion shaft.
What Is CNC Press Brake?
CNC is the abbreviation for Computer Numerical Control.
CNC press brakes are essentially mechanical tools that integrate a computer numerical control system with hydraulic press brakes.
Generally speaking, CNC press brakes are driven by a hydraulic or electrical system.
After being equipped with the computer numerical control system, the press brake is able to effectively and precisely bend metal materials into various desired profiles.
Hydraulic press brakes occupy the vast majority of bending equipment use share. They are the most widely used bending equipment in the bending industry.
The hydraulic press brake is powered by the hydraulic system. Y1 and Y2 axis control oil cylinders directly drive the ram to do the synchronous movement.
Hydraulic press brakes have a long history of utilization and mature technology development.
During the bending operation, hydraulic press brakes are stable and reliable and are very suitable for large volume, heavy tonnage workpiece processing.
The purely electric CNC press brake is driven by an electric motor and does not use hydraulic devices or oil cylinders, so there is no problem with oil leakage.
Also, the motor only starts when bending is required and automatically shuts off when not in use.
This reduces energy consumption and bending costs.
Electric press brakes can provide accurate and fast bending operations.
However, an electric press brake is more suitable for dealing with smaller tonnages.
CNC press brake can be divided into two types according to the movement of the upper tools (punch) and lower tools (die).
It includes a fixed worktable (bottom), which fixes the lower tools (dies) on the table.
The upper tools (punch) are subjected to a downward force, and the upper and lower dies act together on the sheet metal to complete the bending process.
This type of press brake has the same parts as the first type of bending machine.
However, in this type, the upper part is fixed and the bottom part is the moving counterpart.
The bending preparation time of the CNC press brake is very fast because there is a CNC system that accurately calculates the position of the ram and back gauge.
The CNC press brake can also check for errors during the bending process, switch between different bending modes, and position desired to bend angles and lengths.
Additionally, the CNC system is able to calculate the correct bending sequence, repeating the bending action several times until the sheet metal is produced into profiles.
Overall, the CNC press brake is programmable for the entire bending process and is able to provide high-precision, customized bending.
What Are the Types of Press Brakes?
According to the different force application methods, press brakes can be primarily divided into mechanical press drive, hydraulic press drive, and pneumatic and servo press drive.
Although different types of press brake vary in characteristics, the main difference consists in the power running the machine.
Mechanical press brake:
The main parts of mechanical press brakes include a workbench, ram, electric motor, flywheel, clutch, and brakes.
The flywheel is driven by an electric motor. It is connected to the gear shaft through the clutch to maintain the motion of the ram.
The brakes stop the movement of the gear shaft as soon as the drive shaft is disconnected from the flywheel.
Mechanical press brakes are relatively simple in components, so they are relatively easy to handle in maintenance and operation.
Additionally, mechanical press brakes can deal with large tonnages, even two to three times higher than the rated value.
However, mechanical press brakes are not very accurate, as the ram needs to complete the entire cycle when the bending operation starts, and its speed cannot be controlled.
This can be dangerous for the operator and may affect bending accuracy and waste workpieces.
Hydraulic press brake:
The hydraulic press brake drives the ram movement with two synchronized hydraulic oil cylinders.
Due to their high precision and safety, hydraulic press brakes have a long history and are widely used in industrial production.
The light curtain safety device of the hydraulic press brake allows the movement of the ram to be stopped at any time, reverse the operation stroke and control the speed.
Hydraulic press brakes with a CNC system can intelligently handle the bending of different materials, including thickness, length, tonnage, angle, etc.
Hydraulic press brakes are also divided into torsion shaft press brake, mechanical hydraulic press brake and electro-hydraulic press brake.
The disadvantage of the hydraulic press brake is that the bending cannot exceed the tonnage range of the rated value.
Another disadvantage of hydraulic press brakes is that they may be more expensive and require more regular maintenance.
Pneumatic press brake:
The power source of the pneumatic press brake is mainly compressed air or gas.
The air pressure generated by the gas is used to apply tonnage to the ram for bending.
The machine delivers compressed air to the cylinder or pipe connected to the pressure mechanism.
When filled with gas, the pressure drives the tooling downward.
After the movement is complete, the gas is discharged through the exhaust valve, and the brakes return to their initial position.
While the pneumatic press brake cannot match the tonnage provided by hydraulic press brakes, it is very fast and clean during operation.
Servo press brake:
The power of the servo press brake mainly comes from two synchronous servo motors.
The servo motors provide energy through belts and pulleys. The flexibility of the servo press brake is very high.
The stroke and speed of the ram are accurately controlled by the servo motors.
Usually, the servo press brake is suitable for bending a small number of customized workpieces.
Additionally, the tonnages that the servo press brake can handle are also relatively small.
However, the operating sound of the servo press brake is very low and it will not produce noise during operation.
When the bending starts, the servo motors start running, and when it stops, the servo motors will stop as well.
This may save power and reduce production costs.
However, electric press brakes may be more expensive than hydraulic press brakes and may not be suitable for heavy-duty applications.
Moreover, the servo press brake is not equipped with oil cylinders, so the problems of oil leakage and cleaning do not need to be considered.
What Is Finger Press Brake?
The finger press brake is also called box and pan brake.
It is usually used to bend specially shaped workpieces or workpieces that are already semi-finished.
As you can see from the name, box and pan brakes are used to make pans, boxes, and other items.
The finger press brake mainly contains clamping with many parts (fingers) of different sizes.
If different shapes of workpieces need to be manufactured, it is only necessary to remove or replace these fingers according to the bending needs.
Be sure to check that the parts on the clamping are held in place by screws before performing the bending.
When bending a piece of sheet metal, bending of different widths and shapes can be achieved by simply adjusting the size of the top die.
After bending, the formed parts also need to be held in place with screws, rivets or welding.
After long-term use, the finger press brake is easy to wear.
Regular lubrication and maintenance are necessary.
What Is Horizontal Press Brakes?
The horizontal press brake is suitable for high-precision bending, straightening, punching, and shearing.
It can not only bend, fold, punch, and notch sheet metal, bars, and tubes but also straighten defective profiles, shear, and pierce metal plates and pipes.
Moreover, press brakes can be used to produce completely enclosed parts.
Horizontal press brakes can bend tubes into different angles and shapes. These parts can be used to manufacture furniture, cars, metal containers, railings, etc.
The horizontal press brake is capable of cutting sheet metal faster than the shearing machine.
Additionally, it can punch and drill holes in pipes, metal plates or profiles.
Shearing, widening, and narrowing the ends of pipes and connecting different size tubes can be done using a horizontal press brake for the production of furniture, water supply systems, cars, etc.
A horizontal press brake has a wide range of functions and can perform various types of bending.
Therefore, there are many kinds of tooling to match the special functions of the horizontal press brake.
How Does Press Brake Work?
The basic working principle of the press brake is to move the ram using a power device.
The upper and lower tooling can then bend the sheet metal into different profiles according to the preset bending angle.
The main parts of the press brake include the workbench, ram, punch (the top die), and die (the bottom tool).
The driving mechanism can be either a flywheel or an electric motor, and it includes a clutch and brakes.
The sources of force that drive the ram's motion are mechanical, hydraulic, pneumatic, or servo motor.
Although the power system may vary, the basic bending principle is the same, and the only difference lies in the force or tonnage.
The larger the tonnage, the thicker the bendable material.
The bending operator needs to place the sheet metal on the bottom die and initiate the bending program for bending.
Let's take the mechanical press brake as an example.
After the ram and worktable are equipped with corresponding punches and dies, the machine can be started.
The electric motor drives the rotation of the flywheel, which is connected to the drive shaft through the clutch.
The drive shaft connects the rotating flywheel with the ram, which drives the ram to do upward and downward motions.
During this time, the workpiece is fed on the bottom die.
Once the upper die and the bottom die jointly press the sheet metal, a workpiece is formed.
In contrast, the hydraulic press brake mainly drives the ram to move synchronously through two oil cylinders on the side uprights.
The hydraulic press brake can stop and adjust the stroke and tonnage during the bending process.
However, unlike the hydraulic press brake, the mechanical press brake must complete the whole stroke after the stroke starts.
While the stroke can pause, it cannot be reversed.
What Is Press Brake Punch and Die?
Press brake dies are crucial for bending sheet metal.
They consist of the upper die (punch) and the bottom die (die). Only matched punches and dies working together on the metal plate can produce the final profile.
During the bending process, extrusion and friction occur between the dies and the sheet metal, leading to die wear over time.
The huge pressure generated when the dies bend the metal plate can cause the temperature of the contact surface to rise, damaging the dies.
Press brake tooling is not suitable for dealing with metal plates with high hardness and thickness, especially cylindrical workpieces.
The back gauge of the press brake is located behind the machine and is used for positioning the workpiece. The more shafts there are for the back gauge, the higher the bending accuracy of the workpiece.
The controller of the press brake can control the movement of multiple components, including toolings, backgauge, etc.
The light curtain system of the press brake can protect the operator from being injured by the machine.
What Are Press Brake Dies Made of？
Therefore, when selecting press brake dies, it is important to consider the hardness, heat resistance, and wear resistance of the die material.
The hardness, thickness, length and ductility of metal plates should be considered as well.
Appropriate materials for the plate being bent should be selected for the dies.
Generally, the bottom die is used according to the standard of 5 ~ 6T, and the length is longer than the metal plate.
When the material is harder and the thickness is larger, the dies with wider grooves shall be used.
When selecting the punches, the angle of the workpiece should be determined according to the shape of the product, so as to select the appropriate punches.
There are many kinds of materials for press brake punches and dies.
At present, steel is the preferred material for making press brake dies.
For example, carbon tool steel, low alloy tool steel, high carbon high chromium or medium chromium tool steel, medium carbon alloy steel, high-speed steel, matrix steel, cemented carbide, steel bonded cemented carbide, etc.
These high-quality steels are made by special heat treatment, with high hardness, not easy to wear and strong load capacity. But it must not exceed the limited pressure that the dies can bear during bending.
Types of Press Brake Punches and Dies:
90 degree dies, acute angle dies, beading dies, box-forming dies, channel-forming dies, corrugating dies, curling dies, four-way die blocks, gooseneck dies, hemming dies, multiple-bend dies, radius dies, rocker-type dies, rotary bending dies, seaming dies, tube, and pipe forming dies, u-bend dies, and V-dies.
What Are Press Brakes Used for？
A press brake is mainly used for bending and forming metal plates.
In the past, workers could only bend metal plates by pounding them manually.
With the continuous development of science and technology, mechanical press brakes, hydraulic press brakes, and electric press brakes have entered the market one after another.
Currently, press brakes are widely used in various fields of processing and production to improve production efficiency.
Press brakes are mainly used for metal processing and manufacturing in the aerospace, automobile, marine industry, agriculture, energy, military, transportation, and other fields.
In the automotive industry, press brakes can produce body panels, frames, and brackets.
In the aerospace field, press brakes can produce aircraft components and fuselage structures.
It can also produce molded metal shells and covers for electronic equipment.
Safety Measures for the Use of Press Brakes
The press brake operator should follow the following safety measures and practices to avoid potential hazards:
Regular training: Operators need to master the usage methods and various functions of the press brake.
Personal protective equipment: operators need to wear safety eyes, gloves, ear plugs and other equipment.
Machine protective devices: The machine needs to be equipped with protective equipment, such as light curtain protection devices, protective fences, etc.
Regular inspection of the machine: Check if the press brake is functioning properly and if the components are intact.
Why Is It Called a Brake Press?
In Old English, "brecan", "break", "brake" and "breach" are cognate words. "break" is "breken" in Middle English, which means "destroy, break, fragment and bend".
While "brake" develops from "breken" and "break". Therefore, their meaning is also very similar.
In the middle ages, people used "brake" to represent a tool used to pound and crush grain. Later, "brake" gradually became synonymous with “machine”.
Therefore, people called the machine used for pressing as "press brake".
"Press" in Medieval English means "press, strike, hit, pound".
Later, people used "press" to represent a machine used to squeeze clothes or juice.
Therefore, "press" means a tool that can apply force to an object.
"Press brake" in modern machines means a machine that applies force to bend metal plates.
At present, press brake technology has developed into CNC press brakes and robot bending cells.
The most common types of press brakes include CNC hydraulic press brakes, electric servo press brakes, and more.
CNC press brakes with the proper tonnage and length can be selected according to the thickness and length of the bending workpiece.
Our press brakes are equipped with the most advanced and best-guaranteed brand components in the world.
You can consult the product experts of ADH, who will give you the best plan and select the most suitable press brake for your needs.