What is the difference between a burr with a large gap between a stamping part and a burr with a sma

The blanking clearance has a great influence on the quality of the section. When the blanking gap is appropriate, the cracks near the edge of the convex and concave die can coincide in the blanking process, and although the section is not perpendicular to the surface of the material, it is still relatively straight and smooth. Moreover, the burr is smaller, and the cross-section quality of the workpiece is better.

When the blanking clearance is too small, the bending moment in the deformation zone is small and the compressive stress component is high. The upper and lower cracks do not coincide. The material between the two cracks is sheared a second time.

When the upper crack is pressed into the die, it is squeezed by the die wall to produce a second bright band; At the same time, part of the material is extruded, and at the end of the separation, sharp extrusion burrs form on the surface. This is shown in Figure (left).

When the blanking gap is too large, because of the large bending moment and high tensile stress component, it is easy to produce cracks, and the plastic deformation stage ends early. At the same time, the upper and lower cracks do not coincide. After separation, the cross-section slope is increased, the bright band is narrow, the fracture bandwidth is wide, and the burr is high and thick, the fillet is large, the arch bend is large, and the quality of the punching part is not ideal.

1) The gap is too small, the bright belt is interrupted, and there are burrs in the middle, the punching quality is average, and tears will occur on the bright belt in serious cases;

2) The gap is too large, the bright band is very narrow, and it almost disappears in serious cases, while the fault zone is very large, and the burr is very large, which is easy to tear.

Generally, the punching section is clearly divided into three characteristic areas: fillet zone, bright zone and fault zone.

The big one is like stretch wrap.

The burr direction is in the sheet fracture direction. The burr of the punched part is on the side of the die, and the burr of the blanking part is generated on the side of the punch; Due to the presence of a gap between the convex and concave dies, the burr part of the material that exceeds the thickness of the sheet in the direction of separation when the material is pulled off is often referred to as a burr (or batch edge).

The blanking gap is the direct cause of the burr problem, and the accuracy of the blanking gap mainly depends on the CNC machining process. In the process of cutting edge processing and assembly, first of all, the mounting surface of the cutter block is roughened in place, and after the insert is assembled at one time (no pins are installed temporarily), the profile surface is roughened; Then, after the overall heat treatment, the mounting surface of the cutter block is finished in place, and the insert is assembled twice after fire (installing pins) to finish the profile. The machining allowance should be left before the heat treatment of the cutter block, and the processing should be processed to the theoretical blanking gap after heat treatment.

Burrs are generated in the direction of sheet breakage. The burr of the punched part is on the side of the die, and the burr of the blanking part is generated on the side of the punch;

If the punch is flushed up, the product is generally laid flat with the burr below.

That can only be done with a slight polishing and grinding, and then doing other treatments will affect the size of the aperture

The burr is large, the foot is large, the hole is deformed, the local collapse is large, and the raised burr is large.

Reasonable clearance + pressing + cutting edge collapse repair welding.

Is there a problem with checking if the mold has been used for too long? Does the mold match the plate thickness? Generally, the gap of the mold is 10-15% of the plate thickness.

This kind of punching and deburring is now generally used for fluid polishing, with controllable beat and uniform polishing effect.

In this way, the semi-fluid abrasive passes through the inner hole of the stamping part under the action of the pressurization system, and constantly grinds and washes to remove burrs and polish at the same time.

The punch die is worn and the stamping parts punched out have burrs, which may be caused by the following reasons:

1. The abrasives have been seriously worn, and 2. The die discharge is not smooth.

3. The gap is wrong, 4. The gap is deviated, and there are several solutions to the punch burr:

1. Adjust the gap according to the material thickness and generally increase the gap by 10 percent, that is to say, the plate die with 1 mm should be larger than the punch.

2. Adjust the gap deviation to make the gap on both sides consistent.

3. Replace the punch flat grinding and processing die to make it sharper.

4. The die is washed out of the Gongkai return rotation belt to make the leakage smooth.