What to Consider When Designing Sheet Metal Enclosure Structures

Designing Sheet Metal Enclosure StructuresWhat should we pay attention to when designing sheet metal enclosure structures? In sheet metal fabrication we use bending and folding processes to shape plates to a certain angle. So when designing a sheet metal enclosure structure, what should be considered? Let us take a look together with the Shenglin editor.

1. Bend fillet radius: here the fillet radius refers to the inner-edge radius. Too small a fillet radius easily causes cracks, while too large a fillet radius tends to cause springback, so the designed bend fillet and radius dimensions cannot be guaranteed. Different materials have different minimum bending radii, and the designed radius must be based on this. For enclosures that are nearly symmetrical in shape, keep the fillet radii on both sides as consistent as possible to avoid the sheet sliding due to uneven force during bending. Sometimes, for assembly needs, the enclosure has flanges; in such cases a bent edge with a certain radius should be used instead of an overly sharp corner.

2. Springback: springback is also called rebound. Because the bending process includes both plastic and elastic deformation, springback is unavoidable. During design, reasonable bending tolerances should be set; overly tight tolerances can only be ensured by shaping operations, or reinforced ribs can be used to suppress springback.

3. Bend shape. The shape and dimensions of the enclosure should be as symmetrical as possible, so as to prevent the blank from shifting due to uneven force during bending and affecting bend accuracy.

4. Single-side bend height dimension. In sheet metal structures, a single-side bend can act as a reinforcing rib and sometimes even accommodate electronic components, yet the single-side bend height value is often overlooked by designers. Given a determined bend fillet radius, the single-side bend height has a limit; if too small it cannot be achieved on a ordinary press brake and a dedicated die must be designed, increasing processing cost.

5. Design locating holes. To ensure the enclosure does not move during bending, locating holes must be provided. Therefore, locating holes should be fully considered in enclosure design and space reserved for them.

6. Reasonable dimensioning and tolerance annotation. Improper dimensioning of some positions in the enclosure often affects the quality after bending; usually the open edge after the enclosure is formed by bending is used as the datum for dimensioning the relevant positions. Dimensional tolerance is also a matter to note: too high a tolerance grade increases cost or may even be impossible to achieve; too low affects the overall assembly of the equipment. The specific tolerance precision depends on the complexity of the equipment structure.

Sheet metal enclosure structures offer flexible dimensional variation and are easy to standardize and modularize, with simple processing and assembly. However, sheet metal enclosures have poorer dimensional accuracy and their external appearance is not easily made attractive, so they are mainly used in low-volume, multi-variety electronic equipment.

For more information about designing sheet metal enclosures, visit Shenglin Sheet Metal Fabrication.Guangdong Shenglin Exhibition and Display Engineering Co., Ltd.We specialize in the production of sheet metal enclosures, equipment housings and other sheet metal fabricated products, and provide one-stop custom sheet metal fabrication solutions free of charge. Feel free to contact us.