If you’re exploring the metalworking industry, understanding the working principle of rolling machines is essential. Rolling machines play a crucial role in shaping metal sheets and plates into specific curves and cylindrical forms. In this article, I’ll clearly explain the fundamental working principle of rolling machines, outline key steps involved in their operation, and provide insights to help you effectively utilize these machines in your workshop. Whether you’re new to metal fabrication or aiming to deepen your understanding, this guide will clarify all your questions.

The Working Principle of the Rolling Machine

The upper roller of the symmetrical plate rolling machine is at the symmetrical position of the two lower rollers through the hydraulic oil in the hydraulic cylinder acting on the piston for vertical lifting movement, and the final gear of the main reducer drives the gears of the two lower rollers to mesh for rotational movement. The rolled sheet provides torque. The flat plastic metal plate of the bending machine passes between the three work rolls (two lower rolls and one upper roll) of the bending machine. With the help of the lower pressure of the upper roll and the rotation of the lower roll, the metal plate passes through multiple passes.

Continuous bending (the inner layer is compressed and deformed, the middle layer is unchanged, and the outer layer is stretched and deformed) to produce permanent plastic deformation and roll into the required cylinder, cone or part of them. The disadvantage of this hydraulic three-roller plate bending machine is that the end of the plate needs to be pre-bent with other equipment. It is more suitable for large-scale plate bending machines with a plate thickness of 50mm or more. A row of fixed rollers is added under the two lower rollers to shorten two The span of the lower roll improves the precision of the rolled workpiece and the overall performance of the machine.

Continuous bending (the inner layer is compressed and deformed, the middle layer is unchanged, and the outer layer is stretched and deformed) to produce permanent plastic deformation and roll into the required cylinder, cone, or part of them. The disadvantage of this hydraulic three-roller bending machine is that the end of the plate needs to be pre-bent with the help of other equipment. This rolling machine is suitable for large rolling machines with a thickness of more than 50mm. A row of fixed idlers is added under the two lower rollers to shorten the span between the two lower rollers, thereby improving the precision of the rolled workpiece and the overall performance of the machine.

The structural characteristics of the rolling machine

The automatic feeding equipment of the rolling machine is mainly composed of a sheet trolley, an actuator, a sheet transfer mechanism, and an auxiliary mechanism. The sheet trolley is used to place the sheets to be rolled. The main function of the actuator is to transport the plate to be rolled on the plate trolley to the feeding platform. The plate handling operation is mainly applied to the rectangular coordinate manipulator and the vacuum suction cup picking device. In industrial automation systems, it is often necessary to pick up and transport workpieces, and vacuum suction cups are widely used as suction cup manipulators.

The transmission methods of Cartesian coordinate manipulators mainly include mechanical transmission (rack and pinion transmission, synchronous belt transmission, ball screw transmission), linear motor transmission, and pneumatic transmission. The sheet material transfer mechanism is mainly used to transfer the sheet to be rolled, and there are common roller shaft transfers and universal ball transfer. The main function of the auxiliary mechanism is to improve the precision of sheet rolling. Common auxiliary mechanisms include a sheet center alignment device, push device, and displacement detection device.

Frame:

The frame of a rolling machine supports all other components and withstands the mechanical forces exerted during the rolling process. It is typically made of high-strength steel to ensure stability and durability. The robustness of the frame determines the machine’s ability to handle heavy loads and maintain alignment and accuracy.

Rolls:

●Number of Rolls: Rolling machines can be classified based on the number of rolls they contain, commonly two, three, or four. Each configuration serves different purposes:

①Two-roll machines: Simple bending and shaping, primarily used for creating cylindrical shapes.

②Three-roll machines: More versatility, capable of performing both symmetrical and asymmetrical bending. They are common in plate bending.

③Four-roll machines: Offer the best control for precision bending, allowing for easier feeding of material and the capability to roll tighter diameters.

●Material and Hardness: Rolls are made from hardened steel or sometimes coated with other materials to resist wear and corrosion.

Drive System

Rolling machines can be mechanically, hydraulically, or electrically driven. The choice depends on the required precision, speed, and power:

①Mechanical drives are typically used for lighter applications.

②Hydraulic drives offer more power and precise control, suitable for heavy-duty rolling.

③Electric drives provide efficiency and can be easily automated.

Adjustment Mechanism

For three and four-roll machines, the adjustment of the side rolls and the pinch roll is crucial for controlling the bending process and achieving the desired curvature. These adjustments can be manual, motorized, or hydraulic, influencing both the machine’s ease of use and the precision of the final product.

Control System

Modern rolling machines incorporate advanced control systems, including computer numerical control (CNC), to enhance precision, repeatability, and automation. CNC systems can control the movement of rolls, manage rolling speed, and adjust positions based on the input parameters.

Conclusion

Clearly understanding the working principle of rolling machines is crucial for efficient metal forming operations. By properly preparing your metal workpieces, methodically adjusting roller positions, and conducting regular maintenance, you’ll maximize the performance, precision, and lifespan of your rolling machines. For personalized advice, detailed specifications, or additional questions, please don’t hesitate to contact our expert HARSLE team—we’re always here to help you optimize your metalworking processes.

3-Roller Video Demo

4-Roller Video Demo