How to calculate the depth of bend (or the penetration depth of the punch into the die) on a press brake with a given bending angle, measured angle, sheet thickness, and die opening?
The penetration depth of the punch into the press brake die is calculated and controlled when the sheet is bent at a certain angle by air bending on the press brake machine.
This is to control the positioning value of the ram when moving up and down.
The upper die mounted on the ram will bend the sheet to a certain position exactly at the sum of the certain set angle and the rebound angle.
In this way, the workpiece can spring back to the set angle after the ram returns.
However, in actual bending, there are many factors that affect the bending angle of the sheet material.
The measured angle of the first bending often does not match the set angle and needs to be corrected.
At this time, the angular error should be converted into the depth correction value to make it corrected.
Calculated by using the formula for the bend depth of the ram for air bending and the formula for correcting the depth of the ram in case of angular error, we have simplified it into a practical formula that can be applied practically at the production site.
We have made it into an online calculator for your convenience and hope it will help you.
When the punch tip angle is 85°/88°
When the punch tip angle is 28°/58°
- The above calculation is based on air bending
- The lower die opening V during air bending shall generally be equal to 8 ~ 12 times the plate thickness t.
- For the sheet thickness t in the formula, if the sheet thickness thinning caused by plastic deformation of the bent material is considered, t shall be replaced by nt. n is the material thinning coefficient, generally n = 0.98 ~ 0.99