There are about 12,600 existing die-casting enterprises and related companies in China, and about 70% of them produce die-casting parts. Alloys, die-casting machines, molds, smelting equipment, coatings, testing equipment, various raw materials, peripheral equipment, die-casting machine parts and other enterprises account for about 30%. The output of domestic die-casting parts has already ranked first in the world, and the gross domestic product has reached 50. One trillion yuan.

Among the various ownership enterprises, the large-scale annual output of 10,000 tons of die-casting parts, the maximum annual output of 60,000 tons, medium-sized annual production of 5,000 tons of die-casting parts, small-scale annual production of die-casting parts also has hundreds of tons . The proportion of various die-casting parts in the total amount of die-casting parts, aluminum alloy accounted for about 83%, zinc alloy accounted for 15%, Zuojin accounted for 2%, of which about 5.6 million tons of aluminum alloy die-casting parts were produced in 2014.

The main output of die-casting products is mainly automobile and motorcycle parts. The die-casting parts used in each automobile have gearbox housing, cylinder block and crankcase quasi-die casting. The average die-casting part of each car is 75 kg, the total weight. It accounts for more than 50% of the total production of die-casting parts in China.

The manufacturing precision of die castings is very high, mainly including grinding, cutting, welding and other processes.

In the CNC center, five-axis and three-axis CNC machine tools are used for machining. The design of such high-precision machine tools uses a series of high-precision pneumatic actuators such as cylinders. Affected by traditional processes, the finished products produced by most casting manufacturers often have high defect rate, and the processing accuracy is difficult to meet the requirements, and such problems have not been effectively solved. Many companies are confused: Why is the processing precision of the same imported machine tools in domestic production far from the foreign ones?

Through the search for various reasons, it was finally found that the timeliness and accuracy of the operation of a series of pneumatic components such as cylinders in the original CNC machine tools are crucial to the accuracy of the machining, and the motion of the pneumatic components is closely related to the quality of the air source. However, in most of the existing die-casting plants in the configuration of the air compressor system, the most traditional drying method, that is, the post-drying machine, is used for cooling and drying. The compressed air pressure dew point after cooling and drying is generally in the range of +10 ° C to +15 ° C. (higher than the mechanical industry standard JB/T5967-2007 sixth grade requirements);

The pneumatic components used on high-precision CNC machine tools clearly require the pressure dew point to be below +3 ° C (according to the mechanical industry standard JB/T5967-2007 four grade requirements), the moisture content in the compressed air seriously exceeds the equipment requirements.

After finding out the cause, the post-processing equipment was immediately rectified, and the original cold-drying machine was replaced by a core-adsorption dryer. The pressure dew point after replacement could reach -20 °C, which fully met the production requirements. After one month, statistics and analysis were carried out on the precision of the production defective products and finished products, and it was found that the defective products were reduced by 5% and the precision was greatly improved.