Description
Precision molds, as the name suggests, require very high precision in mold processing. There is no unified standard for the specific definition. That is to say, the product requirements are relatively high, and the product size requirements are strict. The product has good consistency, high smoothness requirements, complex structure and durability. These are the basic requirements of precision molds, and the tolerance can reach +-0.001. Compared with ordinary injection molds, precision injection molds are very different in terms of processing equipment and processing methods. For example, the processing method used for ordinary injection molds is wire cutting, while precision injection molds may require slow wire cutting.
Basic characteristics of precision mold processing:
- Complex shapes and surfaces: Some products, such as car coverings, aircraft parts, toys, and household appliances, have shapes whose surfaces are composed of a variety of curved surfaces, and some curved surfaces must be processed using mathematical calculation methods.
- High processing accuracy requirements: A mold is generally composed of a concave mold, a punch mold and a mold base, and some may also be multiple modules. The combination of upper and lower molds, the combination of inserts and cavities, and the joining together of modules all require high processing accuracy. The dimensional accuracy of precision molds often reaches μm level.
- There are many processes involved in precision mold processing: Milling, boring, drilling, reaming and tapping are always used in mold processing.
- Repeatable production: the mold has a service life. When a mold exceeds its service life, a new mold must be replaced, so the production of molds is often repetitive.
- Small batch size: The production of molds is not mass production, and in many cases only one is produced.
- Profiling processing: Sometimes there are neither drawings nor data in mold production, and profiling processing must be carried out based on the actual object. This requires high imitation accuracy and no deformation.
- Excellent mold materials and high hardness. The main materials of molds are mostly made of high-quality alloy steel. Especially molds with long life are often made of ledeburite steels such as Crl2 and CrWMn. This type of steel has strict requirements from blank forging, processing to heat treatment. Therefore, the preparation of the processing technology cannot be ignored, and heat treatment deformation is also a problem that needs to be taken seriously during processing.
The key dimensions of many precision molds are not allowed to have a slope, but when making the mold, the tolerance zone is generally used to add a small slope, such as gear mounting posts, etc. When building a digital model, you must pay attention to the adjustment of tolerances. Generally, the 3D model provided by the customer is useless because many of its dimensions are extreme sizes. If the mold is designed according to this, the mold produced will basically be Scrapped.
Ordinary mold processing and manufacturing methods may not have so many specific requirements. Just follow the normal mold design and processing process.