The design principle of the cold roll-forming machine

The working efficiency of a cold roll-forming machine mainly depends on the shape of the roll and the structure of the production tool. The most widely used production tool is the forming roll. The most complicated problem in the forming of a cold roll-forming machine is the determination of the shape of the forming roll. Increased strip stability and profile quality, as well as increased forming speeds, place higher and higher demands on forming rolls.

The basic principles of the number of forming passes and the shape of the roller are as follows:

1. using the least number of passes and the rollers should material have a uniform and most reasonable deformation.

2. Determine and calculate the vertical and horizontal dimensions of the roll shape based on the selected central axis, which remains constant for each pass. For symmetrical shapes, this axis is the axis of symmetry.

3. Divide the profile into several parts and calculate the length of each part. The total degree of each segment to the left and right of the selected centerline remains the same across all paths.

4. The bending angle of the forming wall of each pair of rollers cannot exceed the following values: thickness ≤ l mm l ~ 2.5 mm > 2.5 mm, the bending angle is 30 ~ 45, 25 ~ 35, 20 ~ 30 (degrees). Larger values ​​are used for the first few pairs of rollers and smaller values ​​are used for the last few pairs of rollers, taking into account that the metal hardens after the material passes through the first few pairs of rollers.

5. In a pair of rollers, the corner of the arc at the bottom of the profile must not exceed 45°.

6. The vertical bending cannot be carried out simultaneously with the arc bending at the bottom.

7. It is recommended that the inclination angle of the upper roller is 1.5~2 degrees larger than that of the lower roller.

8. When the bending inner diameter is small, in order to make the bending of the material easier and calibrate the position of the bending line, a groove with a concave profile can be cold-rolled on the strip in advance. Therefore, it is necessary to manufacture protrusions with a height of (0.3-0.4) sec on the corresponding rollers.

9. The rollers of the last molding press plate should properly take into account the elastic recovery value of the molding.

In order to avoid the profile produced by the equipment, a discharge guide plate is installed to straighten the profile after detaching from the roll press from the last roll. When cold roll forming equipment is designed for the forming process of a specific product, factors that should be considered include forming passes, strip width, roll profile design, forming roll parameters and forming roll material.