When it comes to the metal fabrication industry, metal bending is a fundamental task. A press brake is used for this.
A press brake bends sheet metal and metal plates, usually sheet metal. It clamps the workpiece between a matching top tool and bottom die to bend it. Two C-frames, connected to a table at the bottom and a movable beam at the top, form the press brake’s sides. The upper beam holds the top tool, and the table holds the bottom.
The mechanism of this machine often evokes a common question: how to run a press brake? In this article, we will discuss the answer to it. We will also look at different types and components of press brakes. By the end, you will know how to operate this exciting machine safely.
3 Types of Press Brakes
Press brakes help metal fabricators bend and shape metal sheets to make structures and products. These brakes come in three main types. Knowing the differences between these types is important for picking the right press brake for your job.
1.Mechanical Press Brake
A flywheel, and a clutch power the mechanical drive system when you use a mechanical press brake. The motor gives power to the flywheel, which then gives that power to the press ram.
These machines are usually less expensive than hydraulic ones. That’s why smaller shops on a budget may want to consider them. They do not have the precision, force, or control that hydraulic or electric press brakes do, though.
2.Hydraulic Press Brake
During the bending process, hydraulic press brakes utilize a hydraulic system to move the ram, increasing pressure and force. Compared to mechanical press brakes, this extra power makes bending more accurate and gives you more control.
It is also easy to adjust hydraulic press brakes to work with different thicknesses of metal. They can make complex bends all at once. For their better performance and greater usability, these machines are often more desirable. However, they are more expensive.
3.Electric Press Brake
For fast, accurate, and energy-efficient bending, electric press brakes use servomotors to control the movement of the ram. There are some benefits to these machines over their mechanical and hydraulic counterparts.
For example, they use less energy, have fewer moving parts, and need less maintenance. However, electric press brakes are usually more expensive and might not be as strong as hydraulic ones.
Key Components of Press Brakes and What They Do
A press brake is a complex machine. Generally, these machines have various key components that perform various functions. In order to run this machine, gathering knowledge of all these components is a must. So, let’s look at them in detail.
Frame and Bed
A press brake is built around its frame and bed. Heavy-duty steel is used as its forming material so that it can handle the force that is used during bending.
The workpiece is put on the bed, which is a flat surface. The frame holds up the ram and die.
Ram and Die
The ram and die are two very important parts of a press brake. The ram drives the punch (top die) up and down and presses down on the workpiece, which makes it bend around the die. The die is a custom-made, detachable tool that decides the bend angle and radius.
The backgauge makes sure that the piece to be bent is in the right place. It has many fingers that line up with the bending line. The fingers move the piece into the right place. To fit different bending sizes, the backgauge can be changed by hand or automatically.
To manage and keep an eye on the bending process, press brakes use a number of different control systems. These systems range from easy-to-use manual controls to high-tech CNC systems that ensure precise and consistent bending.
Some of the most important jobs of the control system are
- Setting bending parameters
- Keeping an eye on the pressure
- Making sure the machine works within its limits
Press Brake Forming
After understanding the components, you need to learn about press brake forming. Because if you don’t understand these principles, your efficiency will definitely decrease.
With a press brake, a punch and die set at a certain angle bend or cut metal into different shapes and sizes.
The basic idea behind brake forming is force, which is also written as tonnage. This tells the punch how much pressure it can put on the body during a bend. The thicker the material that needs to be bent, the higher the tonnage, and so on.
In addition to forming tonnage, there is also bending length, which is the longest part of the metal to be bent. Say you have a machine that can bend metal up to 14 feet long. Any sheet metal longer than 14 feet will be too long for that machine to handle.
Different machines with different tonnages and bending lengths are needed for fabrication. It depends on the job and the size and thickness of the material. These things are important because they help figure out the load limit of the press brake, which is given in tons per inch.
Besides, using the wrong tonnage or length can damage or destroy the tools.
How to Run a Press Brake
After you have learned the fundamentals of the press brake, it’s time to run the machine. With the following steps, you can skillfully run any press brake:
- To begin, turn on the power and the key switch on the control panel. Next, turn on the oil pump.
- Before you bend, you need to test and adjust the stroke. The thickness of the plate must be different when the upper die of the machine bends it down to the bottom. Otherwise, the mold and the machine will be broken. There are two ways to adjust the stroke: quickly with electricity or carefully by hand.
- When choosing a bending notch, it is usually 8 times the thickness of the plate. You need to pick a notch that is about 32 for a 4mm sheet.
- After all the other adjustments, place the metal sheet on the workbench. Then, use a backgauge or other positioning tools to make sure it is bent evenly and correctly.
- Like shearing machines, backgauge can be quickly adjusted with electricity and finely adjusted by hand.
- For the bend to begin, press the foot switch. The press brake is not the same as the shearing machine. Everything stops when you take your foot off the pedal.
- Keep a close eye on the metal sheet being bent to make sure the delivery is even and accurate. Do not put your hands or any other body parts near the work area.
- Close the press brake and turn off the power when the job is done. Clean up the work area and put all the tools and supplies back where they belong.
Like any other machinery, the press brake also requires safe operation. Otherwise, it can cause extreme accidents. According to data from the US Department of Labor, 368 amputations happen every year because of accidents involving press brakes.
That’s why you should always strictly adhere to the following safety tips to avoid any worst-case scenario:
- Always follow safe working procedures and wear the right safety gear when needed, such as protective goggles, gloves, shoes, etc.
- Before turning it on, make sure the motor, switch, circuit, and grounding are all normal and firm. Also, make sure the equipment’s working buttons and parts are in the right place.
- Make sure that the upper and lower molds are firm and they fit together well. Also, make sure that each positioning device meets the requirements for processing.
- Run the back-to-origin program when the upper slide plate and each positioning axis are not at the starting point.
- Once the machine is turned on, it should run by itself for one to two minutes. The upper sliding plate should move two to three times in a full stroke. If a strange sound or fault is found, it should be stopped right away. The fault should be fixed, and it can only work again when everything is back to normal.
- One person should be in charge of all the work. It will help the operator closely watch the feeding and pressing personnel to make sure they are all safe before sending out the bending signal.
- The sheet needs to be pressed down before it can be bent so that it does not lift and hurt people.
- The operation must stop, and the power must be turned off when the plate material is pressed.
- Nothing can touch the lower die when the alternative notch on the lower die is changed.
- No one can stand behind the machine while it is running.
- You can not fold the sheet in half along one end by itself.
- The process should be stopped and fixed if the workpiece or mold is found to be wrong while it is being used. To keep your hand from getting hurt, you are not allowed to make any corrections by hand during the operation.
- You can not fold super-thick iron plates, quenched steel plates, high-grade alloy steel, square steel, or plates that are bigger than what the plate bending machine can handle. This is to keep the machine from breaking.
- Always check the degree of coincidence between the upper and lower dies and make sure the pressure gauge’s reading is correct.
- Shut down right away if something goes wrong, find out what caused it, and fix it quickly.
- Before you turn off the machine, put a wooden block on the lower die so that it sits under both oil cylinders. Then, lower the upper sliding plate to the wooden block.
- First, leave the control system program, and then turn off the power.
Running a press brake needs firm knowledge. The first thing to understand are the components of a press brake, such as the punch, ram, die, frame, etc. Then, you should learn about the basic forming principles, like tonnage and bending length.
During the operation, all the steps, from power on to power off, should be strictly followed. Besides, key safety measures like shutting down during abnormalities and adhering to the machine’s capabilities are must to avoid accidents.
But before anything else, you need to make sure you select the right press brake for the job. And with Fab-Line Machinery, you will get just that. Whether it’s hydraulic or electric, you will find the one you want. Contact us today to make the purchase.