One Article to Master CNC Press Brakes: Types, Workflow, Structure & Buying Tips

Metal bending is an indispensable process in the manufacturing industry.Early metal bending relied on manual operation,that is,manual press brakes.With the development of modern technology,in order to meet the needs of rapid market response and reduce production time and material waste,CNC technology came into being.Through the computer CNC numerical control system,the precise bending angle,pressure and position can be preset,and then transmitted to the press brake control axis through instructions,and finally batch,multi-variety,high-precision metal production tasks are carried out.This is the birth of CNC press brake.Today,the editor will take you to quickly understand what CNC press brake is through the definition,type,working principle and other aspects of CNC press brake.If you happen to have this equipment demand,please continue reading!

What is a CNC press brake?

The CNC press brake has a built-in CNC numerical control system,which automatically controls the up and down moving pressure head and mold through a computer program,applies a specific force to the metal sheet,and finally bends it into the required shape and angle(including straight line,V-shaped,U-shaped and other bending processes).The core is to precisely control the bending parameters,including bending angle and radius,through the CNC system,and ultimately achieve mass production and high-precision metal bending operations.

Types of CNC press brakes

1. Hydraulic CNC press brakes

Hydraulic CNC press brakes control the movement of the punch through a hydraulic cylinder to achieve smooth and consistent bending operations on metal sheets. Usually,the tonnage range is high(20-1000 tons or more),the bending force is strong and the speed is fast. It is suitable for thick and tough materials such as steel and titanium,and is widely used in heavy metal processing fields for heavy-duty work.

Application examples:

2. Electric(servo) CNC press brakes

As the name suggests,electric(servo) CNC press brakes are devices that use electric drive systems. The core is low energy consumption,low noise,High speed and high precision,suitable for processing various types of thin sheet metal workpieces with complex shapes. Compared with other models,its operating costs can usually be reduced by up to 60%,which is favored by small to medium tonnage multi-batch workpiece processors.

Application examples:

3. Hybrid CNC press brake

The hybrid CNC press brake is a combination of hydraulic and electric presses. The hydraulic system is used to provide the main bending force for high tonnage,and the servo motor is responsible for controlling the precise bending speed and depth adjustment,thus ensuring high tonnage energy efficiency and providing higher Functional flexibility,suitable for enterprises that produce large quantities of thick materials and need energy saving,is a major development trend of bending equipment in the future.

Application examples:

4. Tandem press brake

Tandem press brake is composed of two synchronously operated press brakes,which can fully synchronize the uniform bending tasks of long materials. It is suitable for enhanced bending processing of ultra-long workpieces(for example,up to several meters). In addition,manufacturers can also Separate them and run them independently. Therefore,having a tandem press brake can flexibly and efficiently handle long and short materials,providing greater flexibility for production tasks.

Application examples:

How does the CNC press brake work?

1. Programming design

The worker imports the CAD drawing of the workpiece into the CNC control system,or directly sets the bending parameters through computer programming,including bending angle,length,pressure,material type,return height,etc.,and finally generates the required bending instructions.

2. Setting the machine

According to the characteristics,thickness,bending shape,etc.of the sheet metal material being processed,the worker selects the appropriate punch and die and installs them on the equipment manufacturer.,and calibrate the machine to ensure accuracy.The upper die includes curved knife die and pointed knife die,while the lower die is classified according to the width of the V groove,generally a 4V concentric die.Through the pneumatic or hydraulic clamp system,workers can complete the die replacement and automatically calibrate the center in a short time.

3. Loading metal plates

The workers place the metal plates in the working area of​​the press brake and correctly position the metal plates through the back gauge device(the workers can set the position of the back gauge according to the program to ensure that each plate is placed in the same position for processing)to ensure the consistency and accuracy of subsequent bending work.

4. Run the program

After loading the program,the bending work starts.

The CNC press brake uses programming instructions to make the upper die(punch)move down quickly(fast forward stage),and then apply pressure to guide the material,forcing the plate to move along the Bend along the contour of the mold and maintain pressure to release internal stress until the material gradually reaches the predetermined angle and shape under the influence of the mold shape(in the working stage,the speed drops from fast to 1-15mm/s);then the upper mold returns and releases the workpiece(return stage).

5. Unloading finished parts

After the process is completed,the worker takes the bent part from the press brake,and the back gauge continues to move automatically to the next bending position,and the cycle is carried out until all processes are completed in batches.

6. Real-time monitoring and adjustment

The CNC system monitors the data of the pressure sensor and angle encoder during the bending process.And automatically adjust the parameters according to the actual processing status.If the material thickness is uneven or the rebound deviation is encountered,the system will automatically adjust the cylinder pressure or perform deep bending compensation to avoid potential processing Errors,ensure the high quality of products,and improve overall production efficiency.Most CNC press brakes on the market are equipped with safety systems to ensure the safety of workers and production throughout the process.

Key components of CNC press brakes

1. Frame and bed

The CNC press brake frame and bed are usually welded from high-strength steel to ensure load-bearing capacity and deformation resistance,and are important structures to support the machine.

2. Hydraulic system

The hydraulic system consists of hydraulic cylinders,pumps,valves,hoses,and hydraulic power units.The hydraulic cylinder consists of a servo valve,a piston rod,and a pressure sensor,and is fixed to the frame on the left and right to convert control signals into mechanical movement,which is the power source of the machine.Electric CNC press brakes are driven by servo motors with an accuracy of±0.005mm,which is efficient and quiet.

3. Ram(upper beam)and punch

The upper and lower beams(also called”punches”)of the press brake are key components for bending metal sheets,and complement the die.The upper die is usually forged from wear-resistant steel and heat-treated to ensure its durability.

4. Die (lower tool)

The lower die is fixed in the V groove of the workbench and used in conjunction with the punch.Its opening width determines the minimum bending radius of the material.Therefore,the shape and size of the die directly affect the final effect of sheet metal forming.When working,workers need to choose the appropriate die according to actual needs.

5. CNC control system

The control system consists of a controller and software,and is the brain of the press brake.It includes a touch screen interface(interface friendliness)and a computer control panel.The CNC control system has functions such as automatic collision calculation and bending sequence optimization.Workers use it to input bending instructions and monitor the machine status,thereby realizing automatic control and high-precision processing.

6. Back gauge

The back gauge is calculated and controlled in real time by the CNC control system,which is used to provide fast and accurate plate positioning during the processing process,thereby ensuring the consistency and accuracy of each bend.The back gauge is generally divided into 2-8 axes,and the multi-axis system can flexibly adjust the front and back,left and right,and up and down heights to adapt to the processing of workpieces of different shapes.Note:Processors need to purchase press brakes with the corresponding number of axes according to their own needs.

7. Safety devices

Safety devices are important components to ensure operator safety,including red laser safety protection curtains,emergency stop switches,safety interlocks and other safety devices.The intelligent protection system can quickly stop the machine when a foreign object enters the work area to avoid accidents.

Advantages of CNC punch brakes over traditional punch brakes

If you have planned to buy an electric press brake, then we need to pay attention to the following matters when purchasing:

Considerations when choosing CNC press brakes

How to choose a suitable CNC press brake depends mainly on your specific production requirements.

1. Material type and thickness

For example,soft aluminum plates and copper plates are suitable for all-electric memory,while high-strength and thicker materials are usually recommended.The pressure tonnage of the press brake is≥120 tons,such as hydraulic or hybrid CNC press brakes.

2. Maximum bending length

Ensure that the working table length of the press brake meets the length requirements of your commonly used workpieces For example,if the length of a conventional workpiece is greater than 3 meters,then a press brake with a workbench length of at least 3200mm should be selected.In addition,it is necessary to confirm that the frame has a compensation function to ensure the accuracy and consistency of the bending of the entire length of the plate.For bending of ultra-long plate workpieces,a tandem press brake is required.

Note:If the project design is complex or multi-axis bending operation is required,it is recommended to choose a CNC press brake with advanced control system and multi-axis function.

3. Required bending force(tonnage)

The tonnage calculation formula is:

P=1.42×TS×L×T2VP=V1.42×TS×L×T2​

Where TSTS is the tensile strength of the material(N/mm2N/mm2),LL is the bending length(mm)TT is the plate thickness(mm),and VV is the lower die opening(mm).

It is recommended to leave a safety margin of 15%-20%.

4. Accuracy and repeatability requirements

Each industry has different requirements for positioning accuracy.When purchasing a machine model,you need to confirm the accuracy difference of the machine model with the equipment manufacturer.For example,the automotive industry generally requires positioning accuracy≤±0.03mm,while ordinary cabinet manufacturing generally requires positioning accuracy±0.1mm.

5. Budget and maintenance costs

In addition to the initial equipment purchase price(generally ranging from 100,000 to 500,000),you also need to consider energy consumption(hydraulic presses are about 100,000 to 300,000 degrees per year,and electric motors only require 30,000 to 80,000 degrees),as well as maintenance costs(hydraulic presses require regular oil changes,while electric equipment only requires regular lubrication).

6. After-sales support and training

This is a factor that many people will overlook,and it is indeed a very important factor.Choose a brand with a local service center,or a brand with a maintenance response time of less than 24 hours(including online remote technical support or on-site technical support).In addition,the technical training content should cover offline programming software,mold maintenance and fault diagnosis,etc.,to help operators reduce errors and improve production efficiency.

Good After-sales support and technical training not only reduce the loss of production stoppage caused by machine failure,but also improve the operation level of workers.

Conclusion

With the development of technologies such as compensation technology and modular multi-station workbench,CNC press brakes in the future will continue to evolve,integrating more advanced functions such as the emergence of automated and intelligent equipment such as robot press brakes,thereby promoting the development of the entire manufacturing industry.

Now you know what a CNC press brake is and its basic working principle.If you happen to have a bending demand,you can select the equipment below.RAYMAX has been specializing in the production of metal press brakes for more than 20 years.We can help you choose the right press brake and provide strong after-sales service.If you need it,you can browse our related press brake pages.There are standard press brakes and retail online press brakes for you to choose from,whether it is a 2-axis press brake to an 8-axis press brake,a 50-ton,300-ton press brake or a 1,000-ton press brake,or a 4-foot,13-foot press brake,there are all kinds of models,which will definitely meet your current needs!Come and contact us~~~