Electrical Enclosure Production Concept
An electrical enclosure consists of a box and a door. Separate lines are generally used to manufacture the doors and the boxes. We are also capable of developing a combined line on which both the box and the door can be manufactured. This production concept discusses the process of producing electrical enclosures from sheet metal.
Where to begin?
There are many different processes that can be used to manufacture the box. Here are a few examples:
- Make the box from a single sheet. The input material is a sheet.
- Use three plates to make the box: a U-shaped box made from a single sheet and two end sheets. The input material is sheets.
- Make the box out of five parts: four side parts and one back part. Metal coil is used to produce the sides and sheet is used for the back part.
A specific production process is selected depending on the required IP value, the production cost of each part, the desired welding process and any post-processing.
From sheet metal to box
The entire production line consists of an input station for the sheets or metal coil, a punching station or laser cutting station, several bending stations and a handling station for transferring parts to the welding station. To enable laser welding, which makes it possible to skip the post-processing step, the bending process must repeatedly produce parts with the same precision. The parts cut from the sheet and the bent products must be highly precise. The edges of the cut-outs serve as the reference points for the bending process. This way we prevent tolerance accumulation. The cutting and bending treatments are performed at the stations using precise NC movements.
In addition, practical tests are used to adjust the cut-outs to create the optimal shape for the welding process and the end product.
From box to electrical enclosure
After the material has been punched or laser cut and bent to create a box, it is transferred to the welding station via a handling station. The welding station generally uses laser welding.
The welding process is selected on the basis of the sheet metal, the production process and the end product’s requirements.
To weld stainless steel materials, we use a special welding head to apply protective gas in order to prevent discoloring as much as possible. When the material’s tolerance is insufficient, causing the gap between several parts to become too large, we employ the laser welding technique with the addition of cold wire. We often recommend the use of laser welding because it creates a precise and clean weld, does not detract from the product’s appearance, provides for a fast-joining method and eliminates the need for post-processing.
In some cases, arc welding is used for the cabinet’s top edge, because, depending on the product, the material’s tolerances are insufficient. This is a common low-threshold welding process that can be deployed quickly and easily.
The biggest challenge in this concept is clamping the material. There must be a precise overlap between the two plates. It is important for the overlap between the two plates to be exact. This requires metal sheet with narrow tolerance. In this phase, clamping, loading and unloading the jig is fully automated using a robot.
The machines can be parametrically constructed whereby continuously variable cabinet dimensions can be selected. Naturally, it is also possible to construct a machine that produces enclosures with fixed dimensions. Everything is possible: a machine capable of producing an infinite number of dimensions or a number of alternatives from which to make a selection in advance.
The complete line (punching/cutting, bending, handling, welding and grinding stations) acquires its information from a Manufacturing Execution System (MES) whereby all information about the bent parts and the production of the cabinet are automatically transferred. Where necessary, the safety systems are also connected together.