How To Bending Closed Metal Box

How To Bending Closed Metal Box

Bending of boxes is the main task for press brake, all electrical metal bending jobs mainly are boxes.

How to bending metal closed boxes?

At first "box" is the application which require sectioned press brake bending tooling. Because of 4 sides it means that you can't use the tool of any length like any opened bend or profile. You will have lateral sides and it means that you need the length of bending punch exactly the same as the length of bending, not more (because you can't of lateral sides) and not less (because you will have not completed deformation at the missed areas). Sectioned press brake tools mainly not are for boxes only but if your box length is outside of standard length of the solid punch it means 100% that you need sectioned tool. And if you have the length which is not corresponded to the sections summary probably you need also the punch cuts with special length. It also means that if your required length could not be divided for 10 mm (because 10 mm is the smallest cutting piece in sectioned tool set) you also have to made the special length piece.
Moreover, probably, if the production of one part is big but you have the necessity to replace the punches on press brake, you should think to have your length in minimum quantity of pieces instead of installation of small sectioned tools. 

But if you have closed metal box even sectioned press brake tools are not enough but you need to have horns. Horn help is required to bend if upper shelf of box will make the collision with the punch (which is normal for closed box). Horns are only solution and equal to the possible width of shelf you can obtain. The bigger shelf require special horns development. Horns could be also really unique if the bending will be of box or panel different than 90 degrees angles. Horns deepness in standard tools is not very big - usually 20-25 mm which is enough for typical boxes. The configuration of closed box and upper shelf is necessary to make the proper welding and probably use some connection points to attach the box so the standard horn is enough. 
Also customer can choose multi sides bending system to bending metal boxes, The biggest difference between single-side bending machine and multi-side bending machine is that the production efficiency is different. Multi lateral bending is formed at one time, and unilateral bending is formed at one time. Workers need to adjust one direction and bend again. And so on. Most of the large-scale elevator manufacturers in China use multi function  CNC bending machines .

 In theory, the working efficiency of multilateral bending machine is four times that of single-side bending machine. That is to say, one elevator can be manually manufactured with one side bending machine, and four can be manufactured with multi-side bending machine.