Bending sheet metal as desired with the roll bending machine

A roll bending machine is a device for the radial forming of flat sheets. It works similarly to a profile bending machine. However, its design is much simpler.

Construction of a roll bending machine

The core of a roll bending machine consists of three steel rolls of the same size. They are arranged in a triangle. The distance between the outer rolls is adjustable. The centre roll is lowered during the bending process. The closer together the outer rolls are and the deeper the centre roll dips between the outer rolls, the narrower the bending radius of the sheet.

Roll bending machines are available in a wide range. The smallest devices are table machines with manual operation by a hand crank. The largest roll bending machines are found in shipyards and can bend sheets several centimetres thick, for example for ship armour.

How the roll bending machine works

The sheet metal is pushed between the rollers. If it is moved during the bending process, particularly large radii can be produced. This is very advantageous for tanks or silos, for example. With the moving bending process, the working range of small bending rollers can be enlarged. The advantage of the bending process is that the sheet cannot buckle during forming. Unwanted hardening or disturbances in the outer geometry are thus prevented. Since a roll bending machine only processes sheet metal, but can produce a wide range of bending radii, it is technically very simple. It is only necessary to replace the bending rollers if they are damaged. Even then, the used rolls can be replaced by simply twisting them off.

Challenges when working with the roll bending machine

Roll bending machines are technically simple devices, no matter how big they are. They quickly deliver the desired result and can be operated safely even by semi-skilled workers. However, it is essential to keep the bending machine as clean as possible at all times. Dirt particles quickly settle on the rollers during the bending process. Any disturbance to the surface of the roller is inevitably transferred to the sheet to be bent. This not only has a visual effect, it can also cause technical problems. This is especially true for coated sheets. If these are even slightly damaged during the bending process, points of attack for corrosion are created. Preventing this is one of the machine operator's tasks. A visual inspection and wiping of the rollers is therefore recommended before each bending process.