How to perform sheet metal bending for rounded steel plates

How to perform sheet metal bending for rounded steel plates

Everyday sheet metal is generally bent right-angle sheet metal parts and partly non-right-angle bent sheet metal parts. There is another kind of sheet metal parts with large rounded corners, i.e. sheet metal parts with rounded arc bending. The common bending dies are 90 degree bending dies, so how to bend sheet metal parts with rounded corners?

With a plate thickness of 2mm bending angle of 120 degrees bending external radius 30 neutral layer radius 29, round bending we count the unfolding to take the arc length of the neutral layer. Therefore, the number of bending knives and the bending angle of each knife are calculated according to the arc length of the neutral layer, and the distance of the neutral layer from the edge is half of the plate thickness.

The above figure in the arc bending to fold how many knives, each knife bending angle how much?

If each knife into 2mm
Bending knife = arc length / 2mm = 30.37 / 2 = 15
Number of bending knives 15
Bending angle
=180- {(2/arc length)X(180-bending angle)}=180-{(2/30.37)X60}=176
Bending angle of 176 degrees per knife
If you can’t measure the arc length during the bending operation, you can also calculate it according to the following formula
Bending angle = 180 – {(2/3.14X neutral layer radius)X180} = 180 – {(2/3.14X29)X180} = 176
If each knife into 3mm in the formula above, replace the 2 in the formula with 3

Of course, the above formula is a theoretical formula, the actual processing and then adjusted according to the results calculated from the above formula.

This method to benefit from the development of modern CNC technology, now the general CNC bending machine with bending arc function. With ordinary bending 90 degrees of the mold, the use of program control multiple times a knife a knife, to complete a small angle large arc processing. The arc length of the large arc is relatively long, the size is far more than the accuracy of the CNC bending machine.

CNC bending machine using multiple positioning bending, complete the overall bending of the arc length of the large circle. Similarly, the CNC bending machine angle control has been very accurate, with multiple small angle bending to complete the large arc angle bending. That said, not very intuitive, look at the scene bending is very clear.

This method is a good solution to the problem of bending large circular arcs of sheet metal, but there are disadvantages. According to the principle, when bending large circular arcs, the number of bends is small and there will be obvious creases. With more bending times, the processing efficiency will be reduced. If the precision of CNC bending machine is not high, the bending angle or bending size will be deviated, requiring high precision CNC bending machine. If, in order to process some large circular arc sheet metal parts, choose a good CNC bending machine.

High-precision CNC bending machine is perfectly fine. The computer controls the flow and pressure of Y1 and Y2 cylinders respectively through two sets of servo bi-directional pump systems, which directly pump the oil from the upper cavity of the cylinder into the lower cavity of the cylinder to realize the lifting of the upper die, and reverse the oil pump to directly pump the oil from the lower cavity of the cylinder into the upper cavity of the cylinder to realize sheet metal bending.

The synchronization of the left and right of the upper die of the bending machine is controlled by two sets of servo bi-directional pumps respectively. Not only high precision, energy saving, low noise, but also more stable and reliable, using less oil, conducive to the manufacture of large stroke ultra-high speed bending machine.