Sheet Metal Bending Design Guide

Bending is a stamping process that uses pressure to force a material to produce plastic deformation, thereby forming a shape with a certain angle and curvature. Commonly used bending includes V-shaped bending, Z-shaped bending and back pressure bending.

The height of the bend

The bending height of the sheet metal is at least twice the thickness of the sheet metal plus the bending radius, that is, H》2t+R. The sheet metal bending height is too low, it is easy to deform and twist when the sheet metal is bent, and it is not easy to obtain the ideal shape and size.

Bending radius

The larger the bending radius of the sheet metal is not the better, the larger the radius, the greater the bending rebound. Then the bending angle and bending height is not easy to control, so the sheet metal bending radius needs to be a reasonable value.
Sheet metal mold manufacturers tend to have a bending radius of 0, so that the radius is not easy to rebound after bending, and the size of the bending height and the bending angle is easier to
control.

Bending direction

When bending sheet metal, it should be perpendicular to the direction of the metal material fiber as much as possible. When the sheet metal is bent parallel to the direction of the metal material fiber, cracks are prone to occur at the bending part of the sheet metal, which is low in strength and easy to break.

Avoid bending failure due to the inability to press the material at the root of the bending

During sheet metal bending,it is often because other features are too close to the root of the sheet metal bending, resulting in the failure of pressing material or the severe bending deformation.

Generally speaking, at least 2 times the thickness of the sheet metal plus the bending radius should ensure above the root of the bend that no other features block the pressing of the sheet metal during bending.

Ensure the bending gap and avoid bending interference

Due to the existence of sheet metal bending tolerances, it is necessary to ensure a certain bending gap in the direction of movement of sheet metal bending to avoid bending failure caused by interference during bending.

Ensure bending strength

Sheet metal bending needs to ensure the bending strength. The long and narrow bending strength is low, and the short and wide bending strength is high. Therefore, the sheet metal bending should be attached to the longer side as much as possible.

Reduce bending process

The more sheet metal bending processes, the higher the mold cost and the lower the bending accuracy. Therefore, the sheet metal design should minimize the bending process

Avoid complicated bends

The more complicated the sheet metal bending process, the higher the mold cost, the lower the bending accuracy, and the complex bending may cause waste of parts and materials. Therefore, when the sheet metal has complex bending, consider removing the complex bending Divided into two parts, assembled by means of pull studs, self-rivet or spot welding.

Holes on multiple bends are difficult to align

Sheet metal bending tolerances are relatively large, especially during multiple bending, the accumulation of tolerances makes it difficult to align the holes with the holes.

The more the bending times of the sheet metal, the larger the bending tolerance. The multiple bending of the sheet metal is difficult to guarantee the accuracy of the size. This is the Reason for alignment on screw hole, stud hole and self-rivet hole on the sheet metal bending.

Solution

Design a hole on a bend into a large hole or a long round hole, which allows a larger tolerance for bending.

Adding two internal positioning holes, and the mold increases internal positioning to reduce the tolerance of the sheet metal during bending, so as to ensure that the holes on the two bends are aligned.