How Does an Electric Press Brake Work? Working Principle, Core Parts and Pros

1. Introduction

An electric press brake is a machine that uses electric drive to bend metal sheets.With the continuous pursuit of high quality, high efficiency, low energy consumption and automation by metal processing manufacturers, traditional press brakes have long been replaced by high-precision, low-energy consumption and easy-to-operate electric press brakes.This article will focus on how electric press brakes work, their advantages and applications.

2. What is an electric brake press?

An electric brake press is a type of press brake used in the metal processing industry.

Compared with traditional press brakes, electric press brakes use advanced servo motors to drive processing materials, and combined with computer numerical control, they can achieve precise bending of metal sheets.

High precision, high energy efficiency, high degree of automation and low maintenance cost have become its synonyms.

3. Working principle of electric press brake

3.1 Working principle

3.1.1 The control system receives programming information

The operator measures the material in advance and combines the processing requirements to program the target angle, bending depth, and related parameters of the material itself. After the control system receives the programming information, it sends precise control signals to components such as the servo motor.

3.1.2 Servo motor drive

The servo motor receives control instructions and drives transmission mechanisms such as ball screws or linear motors, which drive the slider or pull rod to move vertically up and down.

3.1.3 Apply force

When the pull rod moves downward, it will apply force to the metal plate placed on the mold, press the workpiece into the mold, and bend it to the required shape and size.

3.2 Emphasis on precision, energy efficiency and speed

Electric press brakes belong to programmed control bending. The force applied to the material is controlled and carefully calculated, which emphasizes precision more than press brakes without CNC systems.

Because it uses electricity to drive, the energy consumption is also much lower than that of traditional hydraulic press brakes, which is only 15%-25% of the same tonnage hydraulic presses.

In addition, electric press brakes are automated production, naturally high efficiency, and short production cycle.

4. Key components of electric press brakes

4.1 Frame

The frame defines the overall range of an electric brake press, and each component must rely on the frame for assembly and layout. Its main function is to support all parts used for bending, ensuring that the structure of the entire equipment is stable and will not fall apart.

4.2 Bed

The bed is used to place the mold and position the metal sheet. When the upper mold presses the metal sheet into the lower mold, the bed acts as a support plate at this time.

4.3 CNC numerical Controller system

The CNC numerical Controller system is a system that replaces manual automatic control. After the operator sets the preset parameters into a program and implants it into the numerical control system, the part that is manually involved in bending can be replaced by the CNC numerical control system. Compared with manual bending, its advantage is that it can more accurately control the bending angle, depth and speed, improve accuracy and production efficiency.

4.4 Electric servo motor

The electric servo motor drives the upper mold according to the CNC instructions, drives the pull rod to move, and provides precise power for actuators such as the slider and the back gauge. Compared with traditional hydraulic systems, electric servo motors have higher energy efficiency and faster response time.

4.5 Back gauge

The back gauge is a baffle plate that plays a positioning and auxiliary function in the bending process, and its core role is to prevent the metal from shaking and deviating from the preset track during the bending process to ensure bending accuracy.

4.6 Foot switch

When the operator knows that there is a problem with the press brake, the foot switch can control the circuit to turn on and off, so as to free the operator’s hands and allow the operator to pay attention to the problem during operation.

4.7 Quick clamp

Quick clamp is mainly used to fix metal materials to ensure that the material is in a stable state during processing and improve processing accuracy and quality. When fixing, if the upper and lower molds are worn, they can also be quickly replaced.

4.8 Front plate support

The front plate support assists in fixing some heavy, wide workpieces or long plates. For the process of processing metal plates, it provides the necessary support force during the bending process to prevent the material from being deformed due to excessive weight or length during bending.

4.9 Grating ruler

Grating ruler can actually be understood as a ruler, which is mainly used to accurately measure the bending angle and position. The entire system has only CNC system accumulators, which sometimes have some errors. The grating ruler can be fed back to the CNC control system to achieve high repeatability positioning, making each bending more accurate.

4.10 Screw

The screw, also known as ball screw, is a rod connecting the electric servo motor and moving parts, which is the core of the transmission motion, responsible for conducting the rotational motion of the motor, and converting it into linear motion.

4.11 tool (punch and die)

The press brake tool is composed of two parts: punch and die, which directly determines what kind of workpiece to process and what kind of accuracy can be processed. Choosing the right mold shape and material is crucial for achieving the desired machining results.

4.12 Closed electrical cabinet

During the entire system operation, the closed electrical cabinet can protect the electronic control components of the whole machine in the case of leakage or dust, and well isolate dust and electromagnetic interference to ensure the good operation of the whole process.

5. Explanation of the bending process of the electric press brake

5.1 Programming

The press brake operator checks the sheet to be processed in detail in advance, and compiles the parameters such as the bending angle, depth and bending sequence required by the processing into the execution code, and enters it into the CNC control system.

5.2 Setting

The first step is to determine which press brake to choose to meet the processing needs, and then select the appropriate press brake punch and die according to the size of the metal sheet, and install them on the press brake. Then install the back gauge to ensure that the metal sheet can be accurately positioned.

5.3 Positioning

Positioning mainly depends on the joint efforts of the ruler and the backgauge. The work of the ruler is to move the metal sheet according to the set program, and the metal plate is leaned against the backgauge until it is resisted by the backgauge to achieve the purpose of accurate positioning, so as to achieve consistent and accurate bending.

5.4 Bending

The motor is subjected to precise instructions from the CNC system, driving the ball screw or servo drive, moving the punch downwards to press the sheet metal into the die, which is bent to the set angle. The punch is pressed down, then rises again, and then bends the next step according to the instructions.

5.5 Return

After the bending is completed, the slider is retracted, and the tie rod will also be lifted, at which time the operator can take out the metal plate from the press brake to check whether its specifications meet the standard.

6. What are the types of electric press brakes?

6.1 Servo electric brake press

Driven by servo system, it has high-speed response and can bend at high speed. Its distinctive feature is energy saving, making it cleaner than others. At the same time, there is no shortage of high precision, suitable for high-precision machining occasions.

6.2 Electro-hydraulic press brake

Compared with the previous press brake, the electro-hydraulic press brake can use a servo motor to control the hydraulic system to achieve high-tonnage processing. It combines the advantages of electric and hydraulic pressure, maintaining high accuracy and efficient response speed, but also achieving high-tonnage machining needs.

6.3 Hybrid press brakes

Hybrid press brakes are another fusion of hydraulic and electric technology. It has both low energy consumption and high precision, while retaining the enormous power of the hydraulic system. This system is ideal for businesses looking for high precision and large tonnage.

6.4 Direct drive electric press brake

The meaning of “direct drive” is that the motor is directly connected to the slider, without the need for a pulley system, with excellent response speed and vibration resistance, which not only has no impact on high precision and high efficiency, but also reduces energy loss, making these machines extremely energy-saving.

7. What are the advantages of electric press brakes compared to hydraulic press brakes?

7.1 Energy efficiency

Under working conditions, electric press brakes of the same tonnage consume 1/5 of the power of hydraulic press brakes, but their efficiency is much faster. Electric press brakes consume less energy, but can produce more workpieces, and their energy efficiency is very high.

7.2 Accuracy

Under the action of CNC coding and full servo drive, electric press brakes can control the bending accuracy error within 1 micron, while the accuracy of hydraulic press brakes is hundreds or even thousands of times that of electric press brakes, which is a big gap.

7.3 Repeatability

The processing of electric press brakes is very stable, and large-scale production can be achieved without reducing quality. However, after a period of processing, the processing quality of hydraulic press brakes will decline.

7.4 Speed/cycle time

Electric press brakes have the ability to respond at high speed and can run processing at any time. Hydraulic press brakes may take time to build pressure and drive valves, and the running time is slower.

7.5 Maintenance cost

Without considering the damage of parts, the main source of maintenance cost is the cost of raw materials. Electric press brakes do not need to replace hydraulic oil, which mainly consumes electricity, and the cost of electricity is lower than that of oil. Compared with hydraulic press brakes that need to replace hydraulic oil regularly, they can reduce a lot of maintenance costs.

7.6 Environmental impact

Electric press brakes do not have the pollution problem of hydraulic oil leakage, and the noise of electric drive is low, which is a good production environment for processing plants. It is very friendly to the entire ecology.

7.7 Noise level

Unlike hydraulic press brakes, electric press brakes will not make a lot of noise when starting, and the noise level is low, not exceeding 70 decibels at most. Hydraulic press brakes are heavy and inconvenient to run and stop, so they will inevitably produce a lot of noise, generally above 100 decibels.

7.8 Initialization cost

High-precision and high-efficiency electric press brakes have many more advantages than hydraulic press brakes. They are very popular in the market. It is naturally expensive to purchase equipment. Hydraulic press brakes are the most basic and commonly used press brakes for processing, and the initial cost is low.

7.9 Complexity of parts

The structure of electric press brakes is generally simpler than that of hydraulic press brakes. Hydraulic press brakes have complex hydraulic systems such as hydraulic systems, pipeline systems and sealing systems, and the parts are more complex.

8. Disadvantages of electric press brakes

8.1 High initial investment

The cost of electric drive is generally high, and electric press brakes have the characteristics of high precision, high speed and high automation. They are relatively expensive in themselves. The initial investment is higher than that of press brakes of the same tonnage, which increases the initial burden of small and medium-sized enterprises.

8.2 Complexity

It involves many aspects of knowledge such as electrical, servo, CNC, etc., and has high requirements for programming. It is also necessary to master the knowledge related to the power system, which tests the knowledge and technical level of the operator.

8.3 Maintenance cost

Electric press brakes are generally equipped with better parts, but when parts fail, it may cost more to replace specific electric components, especially since electric press brakes themselves are high-end equipment.

8.4 Limited tonnage

Only suitable for processing some small and medium-sized plates, but loses its advantage for super-large thick plates. The tonnage is often not as good as that of hydraulic press brakes, which will be limited in some high-strength processing.

9. Conclusion

Electric press brakes have high efficiency, high precision, high automation, and are green and environmentally friendly. They are not only the first choice for the metal processing industry in modern manufacturing, but also meet the needs of green ecology. They will become the mainstream direction of intelligent and ecological upgrading of sheet metal processing.

With the continuous advancement of technology, electric press brakes will continue to lead the trend in intelligent and flexible development in the future.

If relevant companies are caught in the difficulty of choosing factors such as precision, batch, material, and cost of processed products, please contact well-known manufacturers such as Raymax. Raymax guarantees that it will provide a reasonable and customized selection plan to help every company that chooses Raymax improve production efficiency and reduce costs.