Die failure is the most likely problem in stamping production, which often causes production stoppage and affects the product production cycle. Therefore, when a failure occurs, the cause of the mold failure must be found as soon as possible and repaired reasonably.
During the stamping process, once the mold clamping is inflexible or even stuck, the production must be stopped immediately to find out the cause of the stuck mold and eliminate the fault. Otherwise, the failure will expand, resulting in mold damage.
The main reasons for the die are: poor guide and tilt of the die. Or there are foreign objects between the templates, so that the template cannot be flatly attached; the strength design of the mold is not enough or the force is uneven, causing the deformation of the mold, for example, the hardness and thickness of the mold base and the template are designed too small, which are easily deformed by external forces; the installation of the mold is not allowed. , the positioning error of the upper and lower dies is too poor, or the accuracy of the press is too poor, causing the mold to interfere; the strength of the punch is not enough, and the position of the large and small punches is too close, so that the lateral force of the mold is unbalanced. At this time, the punch strength should be increased to enhance the guide protection of the stripper.
2. Mold damage
Mold damage refers to mold cracking, breaking, opening, etc. To deal with mold damage, the cause must be found from the design of the mold, the manufacturing process and the use of the mold.
First of all, it is necessary to review whether the manufacturing materials of the mold are suitable, and whether the corresponding heat burying process is reasonable. Usually, the heat treatment process of the mold material has a great influence on it. If the quenching temperature of the mold is too high, the quenching method and time are unreasonable, and the number of tempering times and temperature, and the selection of elbows are not appropriate, the mold will be damaged after entering the stamping production.
If the size or depth of the blanking hole is not designed enough, it is easy to block the slot and cause damage to the blanking plate. If the spring force design is too small or the height of the sleeve is not equal, the spring will be broken and the blanking plate will be inclined, resulting in overlapping punching and damage to the parts.
When the mold is used, the position and direction of the parts are installed incorrectly or the bolts are not fastened properly. The working height adjustment is too low, and the guide column is not lubricated enough. The failure of the feeding equipment and the abnormality of the press will cause damage to the mold. If the foreign matter enters the mold, the parts overlap, the waste is blocked, etc., it is not handled in time, and the processing and production continue, it is easy to damage the blanking plate, punch, lower template and guide post of the mold.
3. Mold maintenance
Generally speaking, after the mold is damaged, there is also a choice of repair and scrapping. Unnatural wear failures of stamping dies, such as the destruction of non-critical parts, as well as small punch breakage, punch upsetting and shortening, concave die plate cracking, punching edge cracking and other failures. Most of them can be completely repaired by maintenance methods. Return to the normal state and resume stamping production.
However, when the key parts of the mold are seriously damaged, sometimes the convex and concave molds are damaged at the same time, and the one-time repair cost exceeds 70% of the original cost of the die, or the life of the mold is approaching. The maintenance is of little significance. At this time, you should consider scrapping the mold (except for large molds and continuous molds with complex structures).
When the mold maintenance technology is too complicated, the cost of mold repair is too high, and the difficulty will inevitably make the maintenance cycle too long, which will seriously affect the normal production of stamping, and should choose to fail in advance and scrap it and remanufacture the mold.
Stamping production efficiency and cost are very dependent on molds. For the failure of the mold in the production process, the specific problem should be analyzed in detail, the correct maintenance plan should be formulated, and the problems such as mold damage, mold clamping, sharpening and product quality defects should be solved in time. Only by properly handling the relationship between mold maintenance and scrap can reduce the time for downtime and mold repair, shorten the production cycle, and ensure the normal progress of stamping production.
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