There are about 12,600 die casting enterprises and die casting related companies in China. Companies that manufacture die casting parts account for 70% of the total enterprises and enterprises which produce alloys, die casting machines, molds, smelting equipment, paints, testing equipment, raw materials and die casting machine parts account for 30% of the total enterprises. The output of domestic die casting products has already ranked first in the world, and the gross domestic product has reached 50 Trillion RMB.
Factories with a large scale have an annual output of 10,000 tons of die casting parts and the largest annual output is 60,000 tons; factories with a medium scale can manufacture 5,000 tons of die casting parts and factories with a medium scale can manufacture several hundred tons of die casting parts very year. The proportions of various die casting parts in the total amount of die casting parts are as the following. Aluminum alloys account for about 83%, zinc alloys 15% and magnesium alloys 2%. About 5.6 million tons of aluminum alloy die casting parts were produced in 2014.
The main outputs of die casting products are mainly automobile parts and motorcycle parts. The die casting parts used in each automobile include gearbox housing, cylinder blocks and crankcase die casting parts. The average die casting weight is 75 kg per vehicle, accounting for more than 50% of the total domestic production of die casting parts.
Die casting parts require to have very high accuracy. Five-axis and three-axis CNC machine tools are used for manufacturing products in CNC centers. A series of pneumatic actuators with high accuracy such as cylinders are adopted for these machine tools. The finished products of most die casting manufacturers doesn't have high accuracy, and this kind of problem is not solved properly. We found that the timeliness and accuracy of the action of a series of pneumatic components in the original CNC machine tools are critical to the accuracy of the product. The action of the pneumatic components is closely related to the quality of the air supply. However, most of the existing die casting plants still use the most traditional drying method in the configuration of the compress dry air system, that is, the cooling and drying of the rearmounted air cooler. The dew point of the cooled and dried compressed air is generally between +10℃~ and 15℃, which is higher than the sixth level of standard JB/T5967-2007 in the mechanical industry.
However, the pneumatic components used for high-precision CNC machine tools are clearly required to have a dew point of +3℃, which is lower than the fourth level of standard JB/T5967-2007 in the mechanical industry. The moisture content in the compressed air seriously exceeds the equipment requirements.
Replace an air dryer with a mold core adsorption dryer. The pressure dew point can reach -20℃, fully meeting the production requirements. One month later, we found that the accuracy of the finished product is greatly improved.