Skip to content

Four-roll plate bending machine structure and working principle

4-roll plate bending machine is a type of machine tool used for bending and forming metal plates or sheets. It is similar to a 3-roll plate bending machine, but with an additional bottom roller that provides more precise control over the bending process.

The machine consists of four rollers, which are mounted in a rectangular formation. The top and bottom rollers are adjustable and can be moved up or down to apply pressure to the metal plate, while the two side rollers are fixed in place. The metal plate is fed between the four rollers, which bend and shape it into the desired form.

about 4-Roll Plate Rolling Machine

According to the three-point forming principle, the plate bending machine continuously elastically and plastically bends the plate by utilizing the relative position change and the rotary motion of the work roll, thereby obtaining a workpiece having a predetermined shape and accuracy.

Structure of four-roll plate bending machine

structure of 4-Roll Plate Rolling Machine

The work roll of the four-roll plate bending machine roll consists of four rolls: upper roll, lower roll, and double roll.

The upper roller is the main drive roller and is embedded in the upper and lower frames through the bearing body. Its position is fixed and can only be rotated.

The lower roller is fixed on the bearing seat. To compensate for the thickness of the bent plate, the bearing housing can move linearly within the sliding path of the frame.

The rollers on both sides are mounted on the bearing housing. To obtain a specific radius of curvature of the cylinder, the side roller-bearing housing can be moved up and down at an angle relative to the vertical direction.

  • Left frame
  • Rotary device
  • Roll up
  • Scroll down
  • Beside the drum
  • Balance device
  • Connecting beam
  • The correct framework
  • base

Works Principle

The working principle of a 4-roll plate bending machine involves the application of force to the metal plate through the use of rollers. The top and bottom rollers apply pressure to the metal plate from above and below, while the side rollers provide additional support and help to prevent distortion during the bending process.

The bending process involves the gradual application of force to the metal plate, with the rollers moving in a synchronized manner to ensure that the bend is uniform and consistent. The operator can adjust the position of the top and bottom rollers to control the angle and radius of the bend.

4 steps of the Working process

In general, rolling a metal plate into a cylindrical workpiece on a four-roller plate bending machine consists of four processes, namely: Center-aligned, Pre-bending, scroll, Roundness correction

During the operation of the calendar, the front end of the pressure roller plate is first placed between the upper and lower rollers, and the center (on one side of the high-pressure roller, the platen end is aligned with the side pressing roller) is aligned, and then the lower roller pressing plate is raised. Lift the other side of the pressure roller to apply force to bend the end of the metal plate.

When pre-bending the other end of the plate, the metal plate does not need to be removed from the mill. Move the circuit board to the other end of the machine and pre-bend in the same way.

Then continue to scroll using one feed or multiple feeds until the desired cylindrical radius of curvature is reached

Finally, roundness correction is performed to obtain the desired roundness and cylindricity.

It can thus be seen that when using four rollers to bend the circuit board, the circuit board must be placed once in the rolling mill to realize all the bending rollers.