What is the cause of unilateral burr?

The reasons for unilateral burr are as follows:

1) mould assembly error. If the punch is not perpendicular to the fixed plate or is loose due to wear, or the locating pin is loose, the correct fixed position of the punch and the die cannot be ensured.

2) poor guidance accuracy. The uniformity of the punching gap is affected by the misalignment of the upper and lower die center lines caused by the excessive fit gap of the die guide.      

3) device error. When there is no guiding die in the device, the orientation of the upper and lower die is not allowed to cause uneven gap. The surface of the upper formwork or bottom plate of the mold is not clean, or the screw of the upper formwork is not fastened properly, which will cause the inclination of the working part.

4) deformation during mold operation. Such as punching mattress plate leakage hole is too large, die under the template is too thin, die stiffness is not good and so on in stamping because of mold deformation and affect the gap.

5) the gap between the guide rail of the press is too large, the parallelism between the bottom of the slider and the working table is not good, or the perpendicularity between the sliding direction of the slider and the working table is not good.

6) when the maximum resistance of the workpiece during stamping exceeds 80% of the nominal pressure of the punch, the open punch is easy to deform the "C" shaped bed and make the center lines of the upper and lower dies not coincide.

7) the flatness of the sheet metal is poor, which makes the punch with smaller diameter incline during the metal stamping process.

8) due to the improper material selection, casting and heat treatment process of the die, the deformation of the die occurs during heat treatment or WEDM, which affects the uniformity of the die space.

Article origin: Jiangmen hardware manufacturing and processinghttp://www.xh-mingyuan.com