In the process of sheet metal manufacturing, whether the sample production can meet the quality requirements of customers is the key factor that determines whether the company can receive orders. In the prototype production stage, it is necessary to save costs and produce products that can meet customer quality requirements.
At this time, we will use various simple molds (one upper mold, one lower mold, one pressing plate) and fixtures to produce samples, and many of the produced samples will have convex hulls or pressing ribs.
For such products, simple molds and jigs are used to make them, which will basically cause warping and deformation, resulting in uneven products and failing to meet quality requirements.
The reason for this is that when the upper die (punch) pressing the convex hull or the rib presses the local material of the product into the die, the material other than the die has no resistance (only the material and the die). When the surface friction force) flows into the die, due to the small resistance, the flow deformation speed of the material outside the die is faster than the plastic deformation speed of the material in the die, and the generated internal stress acts on the material outside the die, causing it to produce warping.
At this time, even when the punch presses all the local products into the die, the platen we designed to flatten the material outside the die will also flatten and correct the material outside the die at the same time.
However, when we take out the workpiece or product, we find that the product is still warped, which is why everyone can't understand and wonder. So it takes a lot of time, and there is no guarantee that the product is flat.