The precision of the press brake machine mainly divide into three : wire feeding, bending angle, and swing arm rotation angle. Among them, the wire feeding is 300±0.2mm, the bending angle is ±0.3°, the rotating arm rotation angle is ±0.3mm
Generally, the accuracy of sheet metal processing of press brake guarantees that the linear dimension tolerance is in GB/T1804-M, which is the medium level.
Generally, it need to guarante to be within the tolerance range of 0.2-0.3mm, when using CNC bending machine. To ensure considerable accuracy, It is best to do the following two points:
1.The bending coefficient is the coefficient value obtained from the actual operation, not the theoretical coefficient. The different V grooves used and the different bending tools have an impact on the bending size, and even the thickness of the materials by different sheet suppliers is slightly different.
2.Unfold the drawing. If the shape is more complicated and the bending need complete at one time to ensure that the size is not too certain, you can cut a section of the strip according to the unfolded size for trial folding, and adjust the error before bending the product.
Several factors affecting press brake bending accuracy
When bending, the main accuracy need to ensure is : the size accuracy of the workpiece; the straightness of the bending corner; the perpendicularity of the adjacent surface and the surface roughness during the bending. The analysis of its accuracy is as follows.
1.The accuracy of the backgauge finger is the key to affect accuracy of the workpiece. The error of the finger will copy to the workpiece one by one. Therefore, try to adjust as much as possible to make the specified position of the stopper the same.
2.On the non-indentation mold, due to the movement of the mold when bending the workpiece.
It is difficult for employees to maintain the unity of the movement of the workpiece when clamping the workpiece. So that it slides, and affect the dimensional accuracy of the workpiece. The degree of influence varies according to the proficiency of employees. Therefore, try to use skilled employees when processing such sizes.
3.The selection of workpiece positioning place is different, which will affect the dimensional accuracy. When positioning the workpiece, try to use the previous process , which process the completed part at one time, and use the previous process to locate the edge for the ruler. Avoid copying errors in the previous process to the next process.
4.The upper die and the lower die are not aligned, and the gap is uneven, which affects the dimensional accuracy. And the workpiece is prone to distortion. The angles at both ends are not consistent.
5.When installing the upper mold , the tip of the bending corner not aligned, aligned, or a mold with large wear and tear will affect the straightness of the workpiece.
6.Damage to the lower die and uneven wear have a direct impact on the straightness and verticality of the workpiece.
7.The influence of the lower mold on the verticality, because the manufacturing angle of the lower mold slot is 88 degrees, and the materials we use are different, the bending angle of the upper mold is different, and the corner rebound angle of the workpiece is different during bending. Pay attention to the adjustment of the correction value after programming.