What is the relationship between bending radius and sheet thickness
The bending radius of bending machine is a value that require in sheet metal drawings, and it is difficult to determine its size in actual processing. In fact, the bending radius of the metal plate is related to the thickness of the material, the pressure of the press brake machine and the width of the V groove of the bending die.
The relationship between bending radius and sheet thickness
1.Experience in sheet metal processing shows that when the thickness of the sheet is not greater than 6 mm, the inner radius of the sheet can be directly determined by the thickness of the sheet.
2.When the plate thickness is greater than 6mm and less than 12mm, the bending radius of the plate is 1.25 times to 1. 5 times the thickness of the sheet. When the plate thickness is not less than 12 mm, the bending radius in the plate is generally 2 to 3 times of the thickness.
3.When the bending radius R=0.5, the average thickness T=0.5mm. If the radius size is larger or smaller than the plate thickness, require the special mold .
4.When the metal plate require to bend at 90° and the bending radius is particularly small, firstly doing the planing . The upper and lower molds of special press brake machine molds also need to process.
The bending radius relationship with the V-groove width of the bending die
Through a large number of experiments in sheet metal processing, it shows that the width of the V-groove of the bending die has a certain relationship with the bending radius. For example, 1.0mm plate is bent with a groove width of 8mm, so that the bending radius that is pressed out is ideally R1.
If use the groove width of 20 mm to bend, since the upper punch moves downward during bending, the depth of the stretched sheet reaches a certain angle. Then we know that the area of a 20 mm wide groove is larger than that of an 8 mm wide groove. When bending with a 20 mm wide groove, the stretched area will also increase and the R angle will also increase.
Therefore, under the condition that has the requirement for the bending radius , and not damage the mold of the press brake machine . We try to use narrow grooves for bending.
Under normal circumstances, normally that operate according to the ratio of standard plate thickness to groove width of 1:8. The minimum should not be less than the ratio of plate thickness to groove width of 1:6 for operation. And the sheet metal bending can be appropriately smaller, and it cannot operate less than the ratio of plate thickness to groove width of 1:4.
Recommendation: When the strength permits, the method of first grooving and bending is preferred to make a small sheet metal bending radius.
The bending radius relates to the thickness of the material and the width of the bending die. The simple and convenient, relatively rough method is:
Generally, when the plate thickness is not greater than 6mm, the radius of the plate can be directly used as the radius during bending. When the plate thickness is greater than 6mm and less than 12mm, the bending radius of the plate is generally 1.25 to 1.5 times of the plate thickness. When the thickness is not less than 12mm, the bending radius in the plate is generally 2 to 3 times the plate thickness.
The following figure is the corresponding table of bending radius, pressure and minimum bending height provided by the bending machine manufacturer
V : the width of down die groove
R: bending radius
B: min bending height
S: sheet thickness
