Stamping mold in indispensible equipment in stamping
, having direct influence on improving quality of products, extending service life of product and improving production efficiency. However, stamping mold may lose working dimension due to be wear, which cannot meet production requirements any more. So, improving the durability of stamping mold is the key. The followings are several methods which can improve durability of stamping mold.
Improving design of stamping mold
Proper design of stamping mold is the base for improving durability. So, when designing stamping mold, the disadvantages for products forming should be eliminated, improving durability of stamping mold. For example, the service life of hole stamping mold is shown on the punch pin of hole. For the type of molds, the length of tiny punch pin should be reduced as much as possible for enhancing strength. Meanwhile, guide sleeve should be adopted for strengthening tiny punch pin. Besides, when designing stamping mold, forms of mold base, fixation and guiding form of punch die, pressure center and rigidity of upward and downward template should be taken into full consideration. Particularly for blanking die, gap value has great impacts on durability. During design, proper gap of stamping mold should be chosen. The gap value cannot be too small. Otherwise, it has influences on service life and durability of stamping mold. It is proven that in the situation that does not affect the quality of stamping parts, properly extending gap can highly improve durability of stamping mold, even by several or dozens of times.
Properly choosing materials for stamping mold
Different materials for stamping mold have different intensity, tenacity and abrasion resistance. Under conditions, using high class can improve durability by several times. Therefore, for durability of stamping mold, good materials are necessary.
Toolox series material is new tool steel having high tenacity and high abrasion resistance without internal stress basically. What’s more, the material has extremely high purity, tiny grain size with few content of precipitated carbide. Because of special compositions, Toolox series material has extremely excellent surface treatment performance. Among that, after being nitrided, surface hardness of Toolox44 can reach over HRC65, surface hardness of Toolox40 higher than HRC62 and Toolox33 over HRC58. The largest depth is 1.8mm.
Due to above features, Toolox series material has special advantages when used for partial stamping mold.
1. Used for thicker steel plate, stainless steel plate and stamping mold made of non-ferrous metal plate. Fin mold of air conditioning is an example.
2. Used for drawing mold made of stainless steel.
3. Cold extrusion mold. cold extruding 304 stainless steel whose thickness over 0.5mm has good effects take place of DC53.
4. Used for large stamping mold, required to have high dimensional stability.
Carrying out forging and heat treatment on stamping mold properly
When choosing high quality materials for stamping mold, rational forging and heat treatment should be carried out for the same materials while have different properties. It is one of main ways to improve durability of mold. For example, during quenching, overheat caused during heating cannot only cause overlarge fragility of workpieces, but also easily result in deformation and cracking during cooling, reducing durability. So, when manufacturing stamping mold, proper heat treatment should be mastered.
Toolox material is quenched and tempered steel directly pre-hardened by steel mill without heat treatment. Cooperating with appropriate surface treatment (such as nitridation), high toughness of Toolox materials can realize excellent effectiveness, adding with high hardness on surface.
Arranging manufacturing process of stamping mold rationally and ensuring processing precision
Precision of stamping mold has great influences on durability of mold. Uneven assembling gap of blanking die can break die under shearing force, decreasing service life of mold. Meanwhile, too low surface smoothness of stamping mold also decreases durability of stamping mold. So, dimension of pitch row, perpendicularity of punch pin to bearing surface of dead plate during assembling, even gap of stamping mold, guiding precision of guide pillar should be paid attention. The higher precision of manufacturing and assembling and surface roughness are, the higher durability of stamping mold is.
Correctly choosing press machine
To improve the durability of stamping mold, press machine having higher precision and rigidity should be chosen and the stamping tonnage should be larger than stamping for by more than 30%. In general, using servo punching machine can improve service life of mold by several or even dozens of times.
Properly using and maintaining stamping mold
For improving durability of stamping mold, operator should rationally use and maintain stamping mold. Repair stamping mold frequently in case of the mold having troubles.
Above methods can be used to improve durability of stamping mold. Improving durability cannot only extend service life and reduce production cost of enterprise, but also can ensure the quality of products and improve production efficiency.