Bending is a process of folding and bending flat sheet metal, which follows the cutting process in the entire manufacturing chain. The workpiece is placed on a die with a V-shaped opening. The wedge-shaped tool (top tool) presses the workpiece into the V-shaped opening, bending the sheet metal to the desired angle.
Most bent parts are produced using processes and methods such as air bending, bottom bending, and folding and hemming. These operations follow the same principle: the punch presses the workpiece into the lower die of the die set. Therefore, bending machines that perform these processes and methods are called press brakes.
1. Air Bending
The punch presses the workpiece into the die without touching the die walls. During the downward movement of the punch, the edges of the workpiece bend upwards, forming an angle. The larger the depth to which the punch presses the workpiece into the die, the smaller the angle. There is a gap between the punch and the die during air bending. Air bending is also known as path-dependent bending. Each angle requires a specific path. The machine control system calculates the path and corresponding punching force. The path and punching force depend on the die, material, and product characteristics (angle, length).
2. Bottom Bending
The punch fully presses the workpiece into the die, eliminating any gap between the die, workpiece, and punch. This process is called bottoming. The punch and die must fit precisely together. Therefore, each angle and shape requires corresponding die components. Once the workpiece is fully pressed, the punch cannot continue to move downward. The machine control system continues to increase the punching force until it reaches the specified value. The applied pressure to the workpiece increases, resulting in the contour of the punch and die being imprinted. The angle becomes stable under high pressure, virtually eliminating springback issues.
3. Folding and Hemming
The bending arm of the machine is composed of C-shaped profiles, with lower and upper bending tools mounted on it. During bending, the C-shaped profile moves up or down or performs small elliptical motions, i.e., flipping. The folding and hemming machine operates in a semi-automated manner and is known for its speed and flexibility, even in small batch production. Additionally, the folding and hemming technique allows for efficient bending of multiple radius sizes on a single component using the same tooling.
4. Folding and Hemming
The edges of the sheet metal are typically fully folded (e.g., box edges) and then folded parallel to each other. This provides overall stability to the finished part or forms edge protection. Subsequently, additional components are often inserted into the folded edge. Folding and hemming are completed in two steps: first, the operator pre-bends the 30° angle, and then the workpiece is repositioned and the angle is hemmed. If there is a gap between the edges, it is called folding. In hemming, the bent edges are fully squeezed together. Folding is path-dependent, while hemming is force-dependent.
Industry Applications
Whether it's a microwave, washing machine, or stove, most household appliances consist of structures made from extremely thin sheet metal and extensive forming processes, designed to withstand years of use. Therefore, manufacturers of white goods need production partners with punching and bending machines to flexibly process sheet metal components. Since household appliances often have many visible parts, non-destructive surface processing without pressure marks is essential. Galvanized sheet metal is commonly used in the punching process because the zinc layer is pulled to the edge, preventing future corrosion. Washing machine drums, in particular, require high-quality weld seams to avoid damage to the clothes. Laser welding has proven to be highly effective in achieving high-quality results.
Switch cabinet housings, connectors, and enclosures for electrical equipment are all made from sheet metal structures. High-speed laser cutting machines, punching machines, and bending machines are used to process thin sheet metal components with many bends, often with complex shapes. The flexible processing capabilities of high-speed machine tools are used for inserting elements, forming processes, and contour processing. Laser welding technology also saves time and costs for customers in the electronics industry, as it provides high-quality joints with minimal need for subsequent work.
Most bent parts are produced using processes and methods such as air bending, bottom bending, and folding and hemming. These operations follow the same principle: the punch presses the workpiece into the lower die of the die set. Therefore, bending machines that perform these processes and methods are called press brakes.
1. Air Bending
The punch presses the workpiece into the die without touching the die walls. During the downward movement of the punch, the edges of the workpiece bend upwards, forming an angle. The larger the depth to which the punch presses the workpiece into the die, the smaller the angle. There is a gap between the punch and the die during air bending. Air bending is also known as path-dependent bending. Each angle requires a specific path. The machine control system calculates the path and corresponding punching force. The path and punching force depend on the die, material, and product characteristics (angle, length).
2. Bottom Bending
The punch fully presses the workpiece into the die, eliminating any gap between the die, workpiece, and punch. This process is called bottoming. The punch and die must fit precisely together. Therefore, each angle and shape requires corresponding die components. Once the workpiece is fully pressed, the punch cannot continue to move downward. The machine control system continues to increase the punching force until it reaches the specified value. The applied pressure to the workpiece increases, resulting in the contour of the punch and die being imprinted. The angle becomes stable under high pressure, virtually eliminating springback issues.
3. Folding and Hemming
The bending arm of the machine is composed of C-shaped profiles, with lower and upper bending tools mounted on it. During bending, the C-shaped profile moves up or down or performs small elliptical motions, i.e., flipping. The folding and hemming machine operates in a semi-automated manner and is known for its speed and flexibility, even in small batch production. Additionally, the folding and hemming technique allows for efficient bending of multiple radius sizes on a single component using the same tooling.
4. Folding and Hemming
The edges of the sheet metal are typically fully folded (e.g., box edges) and then folded parallel to each other. This provides overall stability to the finished part or forms edge protection. Subsequently, additional components are often inserted into the folded edge. Folding and hemming are completed in two steps: first, the operator pre-bends the 30° angle, and then the workpiece is repositioned and the angle is hemmed. If there is a gap between the edges, it is called folding. In hemming, the bent edges are fully squeezed together. Folding is path-dependent, while hemming is force-dependent.
Industry Applications
Whether it's a microwave, washing machine, or stove, most household appliances consist of structures made from extremely thin sheet metal and extensive forming processes, designed to withstand years of use. Therefore, manufacturers of white goods need production partners with punching and bending machines to flexibly process sheet metal components. Since household appliances often have many visible parts, non-destructive surface processing without pressure marks is essential. Galvanized sheet metal is commonly used in the punching process because the zinc layer is pulled to the edge, preventing future corrosion. Washing machine drums, in particular, require high-quality weld seams to avoid damage to the clothes. Laser welding has proven to be highly effective in achieving high-quality results.
Switch cabinet housings, connectors, and enclosures for electrical equipment are all made from sheet metal structures. High-speed laser cutting machines, punching machines, and bending machines are used to process thin sheet metal components with many bends, often with complex shapes. The flexible processing capabilities of high-speed machine tools are used for inserting elements, forming processes, and contour processing. Laser welding technology also saves time and costs for customers in the electronics industry, as it provides high-quality joints with minimal need for subsequent work.
