The First Sort
Process parts, these parts directly participate in the completion of the process and have direct contact with the blank, including working parts, positioning parts, unloading and pressing parts, etc.;
Structural parts. These parts do not directly participate in the completion of the process, nor do they have direct contact with the blank. They only guarantee the completion of the process of the mold, or improve the function of the mold, including guiding parts, fastening parts, and standard parts. And other parts, etc., as shown in Table 1.1.3. It should be pointed out that not all dies must have the above six parts, especially single-process dies, but working parts and necessary fixed parts are indispensable.
Modernization of mold manufacturing technology is the basis for the development of the mold industry. With the development of science and technology, advanced technologies such as computer technology, information technology, and automation technology are constantly infiltrating, intersecting, and merging into traditional manufacturing technologies, transforming them, and forming advanced manufacturing technologies. The new stamping die tapping technology has led many stamping manufacturers to reduce costs and caused a panic buying boom.
The development of advanced mold manufacturing technology is mainly reflected in:
Ordinary milling processing uses a low feed rate and large cutting parameters, while high-speed milling processing uses a high feed rate and small cutting parameters. Compared with ordinary milling processing, high-speed milling has the following characteristics:
- a. High-efficiency The spindle speed of high-speed milling is generally 15000r/min～40,000r/min, up to 100000r/min. When cutting steel, its cutting speed is about 400m/min, which is 5-10 times higher than traditional milling processing; when machining mold cavities, its efficiency is compared with traditional processing methods (traditional milling, EDM, etc.) Increase 4 to 5 times.
- b. High-precision High-speed milling processing accuracy is generally 10μm, and some accuracy is even higher.
- c. High surface quality As the temperature rise of the workpiece during high-speed milling is small (about 3°C), there is no metamorphic layer and micro-cracks on the surface, and thermal deformation is also small. The best surface roughness Ra is less than 1μm, which reduces the workload of subsequent grinding and polishing.
- d. It can process high-hard materials. It can mill 50-54HRC steel, and the highest milling hardness can reach 60HRC.
In view of the above advantages of high-speed machining, high-speed machining is being widely used in mold manufacturing, and is gradually replacing part of grinding and electrical machining.
EDM milling (also known as EDM generative machining) is a major development of EDM technology, which is a new technology that replaces the traditional use of forming electrodes to process mold cavities. Like CNC milling, EDM uses a high-speed rotating rod electrode to perform two-dimensional or three-dimensional contour processing of the workpiece, without the need to manufacture complex and expensive shaped electrodes. The EDSCAN8E EDM machine tool launched by Japan’s Mitsubishi Corporation is equipped with an electrode loss automatic compensation system, a CAD/CAM integrated system, an online automatic measurement system and a dynamic simulation system, which embodies the level of today’s EDM machine tool.
Slow wire cutting technology
The development level of CNC slow-moving wire cutting technology has been quite high, the functions are quite complete, and the degree of automation has reached the level of unattended operation. The maximum cutting speed has reached 300mm2/min, the machining accuracy can reach ±1.5μm, and the machining surface roughness Ra0.1～0.2μm. The development of the thin wire cutting technology with a diameter of 0.03～0.1mm can realize the one-time cutting of the concave and convex mold, and can cut the narrow groove of 0.04mm and the internal fillet with a radius of 0.02mm. The taper cutting technology has been able to perform precision machining of tapers above 30°.
Grinding and polishing processing technology Grinding and polishing processing are widely used in precision mold processing due to the characteristics of high precision, good surface quality, and low surface roughness value. Precision mold manufacturing widely uses advanced equipment and technologies such as CNC forming grinders, CNC optical curve grinders, CNC continuous track coordinate grinders and automatic polishing machines.
The complexity of the product structure will inevitably lead to the complexity of the shape of the mold parts. Traditional geometric inspection methods can no longer adapt to the production of molds. Modern mold manufacturing has widely used three-coordinate numerical control measuring machines to measure the geometric quantities of mold parts, and the detection methods of mold processing have also made great progress. In addition to the high-precision measurement of complex surface data, the three-coordinate numerical control measuring machine has a good temperature compensation device, reliable anti-vibration protection ability, strict dust removal measures and simple operation steps, which make on-site automatic detection possible.
The application of advanced mold manufacturing technology has changed the traditional mold making technology that mold quality relies on human factors and is difficult to control, making mold quality dependent on physical and chemical factors, the overall level is easy to control, and the ability to reproduce the mold is strong.