When the small scimitar can not avoid the position, it is necessary to use the large scimitar to avoid the position, as shown in figure (6)
sometimes there will be a large machete that cannot be avoided, then you need to increase the process:
First, press a mark on the bending line-as shown in Figure (7), for better bending, you can first bend this bend to a certain angle to avoid touching the knife, and then press the edge to 90 degrees-such as Figure (8), in general, the embossing process can be applied to the bending can not be completed at one time, so that when the second bending, the bending line can be better shaped according to the original bending, otherwise it is prone to secondary bending And it causes the phenomenon that the bending is deviated or the bending angle is not well controlled.
Therefore, such problems should also be considered in the design process, and try to avoid using such a process ,because it does not have a direct bending effect, and the size and angle may be different. The bending machine can also be used to press the work edge.First bend the work piece to 30 degrees, and then press the work piece with a flat knife.Generally the pressing edge that can be completed with an ordinary punch had better not be arranged to the bending machine ,because the effect of the puching machine is relatively better.
In addition to the interference of the workpiece and the bending knife during the bending process, when the size of the workpiece is relatively large, it may
Interfere with the bending machine when bending occurs.
When we arrange the process, we often have to consider whether it is easy to bend and whether it can be bent.Because bending is a very important process, the good operation of bending directly affects the guarantee of the quality of the bending, and the quality problems that often occur due to the bending size is not well controlled, so in the design process special attention should also be paid to the issue of bending, which is related to the stability of quality during mass production.
For different plate thicknesses, its bending size is limited and cannot be too small. Generally, it is related to the lower die. The general principle is: the lower die selects a knife groove with 6 times the thickness of the plate, so the bending coefficient The most consistent with the experience value. The classification of general sipes is shown in figure (9) according to the outer width of the sipes, which are No. 6 and No. 10 respectively.
However, when using a small enough knife groove to bend, it is easy to appear indentation, generally the indentation below the 6th slot is more obvious, so when the surface of the workpiece is not treated, when the bending edge is relatively small, there are obvious indentations, which will affect the appearance and rust easily.
It can be seen from the figure (10) that for the slot 10, the distance from the bending line to the positioning edge must be greater than 5.0 mm before it can be bent. It can be seen that the No. 4 groove is generally the smallest sipe, and the distance between the bending line and the positioning edge needs to be greater than 2.0mm, while the No. 4 groove is mostly used for thin plates (less than 1.2mm), because if you bend a thick plate, you need to The pressure is relatively large, when the groove is small, it is easy to crush the knife groove.
So for 1.0mm board, the bending edge is better than 3.5mm (there will be indentation), for 1.5mm board, the bending edge is better than 5.0mm. It is better if the bending edge of the board of 3.0 is better than 12mm. Such problems can be considered during the design process.
In the actual bending process, various problems will be encountered. Many times, the influence of bending on other processes will also be considered. Many times, specific problems will be analyzed, and the process will be properly arranged.
At the same time, under some special needs, the supplier will also manufacture special bending knives, but if the shape of the tool is stranger or the curvature is larger, it will inevitably affect the rigidity of the tool and reduce the tool life.