Sheet Metal Bumping Bending Press Brake
CNC Press brakes use the specific tooling system (general or special bending tools) to bend the metal sheet in the cold state into workpieces with various geometric cross-sectional shapes. Normally use CNC controlled auto bending system or software for folding sheet profiles.The coordinate axis has been developed from a single axis to 12 axes. The CNC system can automatically realize the ram bending depth control, the left and right cylinders adjustment of the top bending beam, the front and rear adjustment of the bending back gauge, Z1&Z2 axis adjusting, the pressure tonnage adjustment and the slider approaching working speed adjustment.
CNC press brake can can easily realize the ram down, jog, continuous, pressure holding, return and stop in the middle, and complete the bending of multiple elbows with the same angle or different angles at one time.
To apply the bumping method, the following parameters must be programmed:
Radius
The more segments you select, the more bends will be used to create the programmed radius within a smaller tolerance. With a high number of segments you will need a smaller V-die opening to be able to bend in a proper way.
When a product has a radius bend, the segment size is computed from the number ofsegments, which has been defined by the user. Standard the first and last segment are calculated half the size of the mid segments to obtain a better result. However, it can be a problem selecting a die suitable to bend these small segments. Therefore the control can calculate an equal size for all segments. This can be defined with this parameter.
• Disabled (no equal sizes)
Bend Type. You will be prompted to program the radius, the number of segments and if you like to have equal bumping segments or not. After programming these parameters the radius is drawn in the product and a message will appear on the screen with information about the smallest calculated segment length. The smallest segment length has consequences for the selection of the die.
How to calculate bending big Radius sheet profiles? How many bends required for each step?
The plate thickness is 2mm, the bending angle is 120 degrees, the bending outer radius is 30, the neutral layer radius is 29, and the arc length of the neutral layer is taken for arc bending. Therefore, the number of bending knives and the bending angle of each knife are also calculated according to the arc length of the neutral layer, and the distance between the neutral layer and the edge is half of the plate thickness.
In the figure above, how many bends should be folded for arc bending, and what is the bending angle of each bends?
If we use 2mm per bends.
Number of bending tools = arc length / 2mm = 30.37/2 = 15
Number of bending tools: 15
Bending angle=180 - {(2 / arc length) x (180 bending angle)} = 180 - {(2 / 30.37) X60} = 176
Bending angle of each knife: 176 degrees
If we can't measure the arc length during bending, we 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 you want to use 3mm per knife, replace "2" in the above formula with "3"
Of course, the above formula is a theoretical calculation formula. In actual processing, adjust according to the results calculated by the above formula.
