In our mold production process, there are often instances of poor dimensions in bent parts, with some angles being inwardly biased and some outwardly biased. In most cases, the bias is outward. Cases of inward bias are relatively rare, as shown in the diagram below:
When inward bias occurs, we need to check if the pressure ribs of the bending die block are too high. This situation is difficult to occur in molds that are already in normal production but may occur during the trial production of new molds. The handling methods are as follows:
1. Reduce the height of the pressure ribs on the bending die block.
2. Reduce the contact area between the bending punch and the material.
3. Increase the bending clearance.
4. Readjust the mold's closing height to ensure a tight fit.
5. Increase the press speed. Sometimes, a slow press speed can also cause inward bias, although this possibility is minimal.
Outward bias is a common occurrence that we often encounter, even in molds that are already in normal production. This situation is frequently encountered during mold repairs, as shown below:
The handling methods for outward bias are as follows:
1. The mold is not tightly closed.
2. Increase the height of the pressure ribs on the bending die block. If there is a radius, consider reducing the radius while ensuring it does not affect the product dimensions. Sometimes, the sharp corners above the pressure ribs on the bending die block may wear during production, requiring us to sharpen the rounded corners that have worn out to ensure the pressure ribs can enter the material.
3. Increase the contact area between the bending punch and the material by raising the height of the bending punch.
4. Reduce the bending clearance. For old molds, consider replacing worn-out bending punches.
5. Reduce the press speed.
Sometimes, the unstable dimensions in bending may be caused by other factors. For example, when there is scrap on the mold, it may prevent the mold from closing tightly, among other issues. You can refer to an article on the reasons and repair methods for scratches, dents, and cracks on the external surface of bending mold products, which can cause outward bias. Therefore, when repairing molds, it is important to first eliminate some external factors.
When inward bias occurs, we need to check if the pressure ribs of the bending die block are too high. This situation is difficult to occur in molds that are already in normal production but may occur during the trial production of new molds. The handling methods are as follows:
1. Reduce the height of the pressure ribs on the bending die block.
2. Reduce the contact area between the bending punch and the material.
3. Increase the bending clearance.
4. Readjust the mold's closing height to ensure a tight fit.
5. Increase the press speed. Sometimes, a slow press speed can also cause inward bias, although this possibility is minimal.
Outward bias is a common occurrence that we often encounter, even in molds that are already in normal production. This situation is frequently encountered during mold repairs, as shown below:
The handling methods for outward bias are as follows:
1. The mold is not tightly closed.
2. Increase the height of the pressure ribs on the bending die block. If there is a radius, consider reducing the radius while ensuring it does not affect the product dimensions. Sometimes, the sharp corners above the pressure ribs on the bending die block may wear during production, requiring us to sharpen the rounded corners that have worn out to ensure the pressure ribs can enter the material.
3. Increase the contact area between the bending punch and the material by raising the height of the bending punch.
4. Reduce the bending clearance. For old molds, consider replacing worn-out bending punches.
5. Reduce the press speed.
Sometimes, the unstable dimensions in bending may be caused by other factors. For example, when there is scrap on the mold, it may prevent the mold from closing tightly, among other issues. You can refer to an article on the reasons and repair methods for scratches, dents, and cracks on the external surface of bending mold products, which can cause outward bias. Therefore, when repairing molds, it is important to first eliminate some external factors.
