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In the field of metal processing, CNC press brake bending technology is like a bright pearl, is the metal plate into a variety of practical parts of the key, the importance of its resonator as in laser technology. With a unique process and advanced bending machine, press brake bending not only to achieve high-precision processing, but also to meet the needs of diversified production for the development of many sheet metal industries to provide a solid support.
press brake machine bending is essentially the process of using a press brake to mold sheet metal into a specific shape by applying pressure to the sheet metal through a punch and die. This process occupies an indispensable place in the field of manufacturing and production, and is capable of skillfully transforming raw sheet metal into components with real-world functionality.
When a sheet metal press brake performs a bending operation, the sheet metal undergoes subtle changes. During the bending process, there is a slight elongation of the metal. This is due to the fact that as the sheet bends, the outer side expands as it is stretched and the inner side is compressed, and the interaction of these two forces causes the neutral axis (the boundary between compression and expansion) to move toward the inner bending radius.
There are many different types of press brakes, each with its own unique purpose.
Known for its versatility, servo / cnc hydraulic press brake is powered by hydraulic oil and two synchronized hydraulic cylinders. It is capable of adapting to a wide range of materials and complex processing needs, and is widely used in aviation, wind turbine components and farm equipment parts metalworking.
Characterized by being equipped with a flywheel, a crank mechanism and a clutch, mechanical press brake machine are capable of fast and efficient bending operations and are suitable for scenarios that require high production speeds.
Offer high precision and programmability through computerized operation. CNC press brake with quick tool change system is able to accurately control the bending angle, depth and other parameters to meet the processing of complex workpieces that require high precision.
CNC press brake is widely used in the manufacturing of car body panels, aircraft aluminum panels, building doors and windows, and electrical cabinets, serving industries such as automotive, aerospace, construction, and electrical equipment manufacturing.
The main difference between these press brakes:
Power source: hydraulic fluid, mechanical force and computer control, respectively.
Accuracy: CNC press brakes usually provide more accurate results.
Speed: mechanical press brakes tend to be faster than hydraulic press brakes.
The first step in the bending process is to load the sheet metal onto the press brake. The material is usually placed on the machine’s table and made sure that it is aligned with the centerline of the tool. Once aligned, the sheet metal is held in place using a press brake clamp or back stop system. These modular press brake tooling systems ensure that the material remains stable throughout the bending operation, preventing any movement that could affect bending accuracy.
Once the stainless steel material has been secured, the press brake needs to be set up correctly. This includes selecting the proper press brake punch and bending die for the type of material, thickness and required bending radius. The press bending machine operator also needs to adjust the bending angle, stroke length and the force applied by the press brake. In addition, it may be necessary to caalibrate the machine’s control system for specific part sizes to ensure that bending is performed within specified tolerances.
Once setup is complete, the bending operation can begin. The press brake applies pressure through a punch that presses the sheet metal into the die to create the desired bend. The applied force is precisely controlled to avoid cracking or improper bending of the material. Throughout the stainless sheet operation, the operator monitors the bending depth and angle for accuracy. If the press brake machine is equipped with a advanced CNC control system, the bending parameters can be pre-programmed, allowing the press bending machine to automatically adjust for optimal results.
After bending is complete, the operator inspects the part to verify that the bending meets the required specifications. If necessary, adjustments can be made to the bending machine or the mold. Depending on the complexity of the steel sheet part, additional machining, such as finishing or trimming, may be required to refine the shape and ensure that the part can be accurately assembled into the final product.
Adaptability to production needs: A press brake is able to meet the needs of small lot and multi-variety production. This is because it can handle different materials and parts using the same set of punches and dies.
Bending molds are cost-effective: the bending molds used in press brakes have a long life，with proper maintenance, they last at least 10 years (up to 15 for high-quality ones). Each set costs only $3,000-$8,000, cutting die manufacturing costs by ~35%.
Ideal for “S” and “U” shaped parts: Stamping and molding technology has a problem with springback in the production of U-shaped parts, which can be solved by efficiently performing multiple bends on the press brake.
Accelerate new product trials: The versatility of the press brake allows for trial production without additional costs or tooling adjustments. Parts of all shapes, sizes and angles can be produced with just one set of punches and dies.
Complex polygonal shapes can be produced: Adjustable material settings on the sheet metal press brake machine provide the flexibility to accurately form polygonal workpieces of varying heights.
Deflection compensation improves accuracy: Long metal workpiece bending brings uneven center angles (needing manual fixes), while CNC press brakes’ this feature allows precise angle adjustments for straight bending, reducing labor and enhancing quality.
Disadvantages of Press Brakes
Material Thickness Limitations: Materials up to 50mm thick can be easily processed by press brake, but materials beyond this range require more force and a more powerful press brake.
Risk of breakage: Burrs or oxide layers on material edges/corners during bending may cause cracks/breaks under pressure, making high-quality bending hard and risking material integrity.
Indentation problems: Press brake tools operations often see bending surface indentations, caused by poor/inappropriate tooling. These need extra grinding and meticulous testing, raising production time and costs.
Accuracy Determination Challenging: Mistakes are often made during the bending process, as some irregularly shaped metals tend to slip. Square metals may not experience this problem, but irregularly shaped parts tend to slip and thus fail conformance checks.
A press brake is a key tool for metal bending, which uses a punch and die to create precise bends in sheet metal. If this machine is used, several technical parameters need to be considered, including the tonnage that determines the amount of force it can exert and the width of the table that determines the maximum length of sheet metal that can be bent.
Versatile sheet metal press brakes, such as box and tray press brakes or cornice press brakes, can be used to bend small and medium-sized parts to form simple curves and creases. The main factors in selecting this type of press brake include the maximum bending length and the specification of sheet thicknesses that can be handled.
Plate rollers or roll press brakes process sheet metal into curves or cylinders. They have three rollers arranged at an angle to form a triangle. Key features of any plate press brake include the ability to handle material thickness and the diameter of the rollers that affects the minimum bending radius that can be achieved.
Using these tools and machines ensures that sheet metal bending projects are accurate, efficient and cost-effective, resulting in higher quality manufacturing results.
Failure to achieve the required bending angle is characterized by over-bending or under-bending. High-quality bending tools can be used and accurately controlled to ensure that correct measurements and adjustments are made. Verify the bending angle by using a protractor or angle gauge and adjust the applied bending force according to the type and thickness of the material to avoid overbending or underbending.
Cracking or splitting may occur during bending, especially for brittle materials or when bending at acute angles. Therefore, a large bending radius should be selected to match the material to the type of bend. Maintain an inside bend radius of at least 1.5 times the material thickness to minimize stress concentrations and prevent cracking.
After bending is complete, if the material tries to return to its original shape, this can result in inaccurate angles. This can be slightly mitigated by slightly over-bending or using a material with a lower yield strength. Depending on the type and thickness of the material, consider the yield strength of the material and typically overbend by 1 – 3 degrees.
In metalworking, mastering press brake bending is key to efficient, accurate production. Whether you’re an industry veteran or a novice, choosing the right press brake and bending process delivers twice the result with half the effort. For quality press brakes and professional bending solutions, contact HanChine. We offer a full range of press brakes in various types and specs to meet your diverse needs.
