I. In the design and manufacturing process of blanking dies, the following five points should be noted:
1. Price:
In the design and manufacturing process of automotive stamping dies, the first consideration is their price, which ultimately affects product sales.
2. Quality:
Stamping dies often determine the safety factor of automobiles; therefore, the quality of the dies directly impacts product sales.
3. Humanization:
In addition, in die stamping design, humanization is also an important factor to consider. At the same time, attention should be paid to its maintenance and servicing aspects, making the local replaceability of the die stronger. For parts that are used more frequently, higher standards should be set in the design, which is highly beneficial for both parties. However, the Chinese automotive industry rarely considers the humanization of stamping dies, simply focusing on the simplification of processing and production processes, resulting in a lack of standardization of die components and making maintenance more difficult.
4. Raw Materials:
In recent years, China has had significant advantages in selecting materials for automotive stamping dies, with alloy steel or alloy cast iron being commonly used.
5. Precision:
In the mold manufacturing process, the degree of fit and consistency of clearances between components directly affect the precision of each component.
2. Maintenance and Repair of Automotive Stamping Dies
Due to the harsh working environment of automotive stamping dies, issues such as wear and even damage to working components, mating components, and sliding parts frequently occur during use. However, because die design and manufacturing are complex, high-precision, time-consuming, and costly, problems should be promptly repaired during use to ensure precision and extend service life.
Although the maintenance and repair of automotive stamping dies is highly complex, the common faults and repair methods mainly fall into the following seven categories:
1. Deformation of parts during flanging and forming:
Workpieces, especially surface parts, often deform during flanging and forming processes, significantly affecting part quality. The usual solution is to increase the blank holder force. If spring blank holders are used, springs can be adjusted; for cushion blank holders, the cushion force is typically increased. If local deformation persists after increasing pressure, the specific issue must be identified—check whether the blank holder surface has local depressions. In such cases, weld a patch plate onto the blank holder, then grind and fit it to the lower die surface.
2. Chipped cutting edges:
Cutting edge issues are among the most common problems encountered during die use. For example, for small cutting edge profiles, use a grinder to grind the chipped area, then weld it with the appropriate electrode to ensure a strong weld that resists further chipping.
3. Galling:
Galling caused by chipped edges mainly occurs in operations such as drawing, forming, and flanging. Locate the corresponding galling area on the die, flatten it with an oilstone—ensuring uniform corner radii—and then polish with fine sandpaper.
4. Trimming and punching with material:
During trimming or punching, abnormalities in the die material or stamping device cause trimming and punching with material. In this case, the corresponding parts of the die should be identified based on the part. If there is an abnormality in the die's stripping plate, repair welding should be performed on the pressure plate. If there is no issue with the die's pressing action, check whether the die cutting insert has any galling or scoring.
5. Scrap being cut:
Due to operators failing to remove scrap in a timely manner during production, scrap accumulates. Eventually, under the pressure of the trimming cutting insert, the scrap cutter edge chips, causing the scrap to be cut. The repair method is similar to that for trimming edge chipping.
6. Burrs:
Burrs occur on parts during trimming, punching, and blanking due to the clearance between the die cutting edges. When the clearance is too large, the trimming and punching processes use the method of dressing the die with the punch. In the blanking process, the punch is dressed while the die remains unchanged. When adjusting the die clearance, it should be adjusted based on the size of the clearance to ensure it is reasonable. For trimming and punching dies, the clearance is placed on the die side, while for blanking dies, it should be placed on the punch side to ensure that the part dimensions do not change before and after repair.
7. Punching scrap blockage:
Blockage of punching scrap is caused by uneven scrap chutes, reverse taper in the scrap chute, or failure to clean scrap in a timely manner. Surfaces A and B are smooth and have equal diameters, which can ensure that scrap is not blocked.
The above content relates to the design, manufacturing, and maintenance of automotive stamping dies. Currently, there are numerous stamping die design companies in the market, but their quality varies greatly. Therefore, choosing the right die processing enterprise is very important. It is hoped that this article can be helpful to readers.