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Welcome To Sand Casting Org

Minghe Sand Casting Org Is Professional Sand Casting Encyclopedia Base.

Background

The foundry industry has always enjoyed the title of “Mother of Industry”, plays a pivotal role in the national economy, and is one of the foundations of the modern machinery manufacturing industry, as well as an important part of the modern manufacturing industry. Casting parts have the advantages of a wide range of applications, not limited by metal types, simple production processes, and the ability to produce complex and large castings. Therefore, the casting industry has always occupied aerospace, automotive, shipbuilding, electric power, textile, equipment manufacturing and other industries. Very important position. As an ancient industry, the foundry industry has a long history in China and has made great contributions to the development of the world foundry industry and the improvement of foundry technology. According to relevant data, my country has become the world’s largest foundry country since 2000. The output of castings produced by it is Germany, Japan, and the United States.

The total output of a large industrial country, but the energy consumption and raw material consumption of castings are serious, the processing cycle is long, the production efficiency is low, and the share of high-quality castings is very low. In addition, the design of modern new products is developing towards individuality and small batches, and parts and components have become increasingly complex, thin-walled, and integrated manufacturing. These trends have increased the difficulty and cycle of new product development. The traditional sand casting made of wooden molds is still the main production method of casting technology , but there are problems such as complicated molding process, long manufacturing cycle, high production cost, rough surface and poor dimensional accuracy, and low product qualification rate. , it is difficult to meet the requirements of key castings in key industries such as aerospace and automobiles, so the manufacturing and forming technology of high-quality castings is in urgent need of research and development. In recent years, with the rapid development of science and technology, many new sand mold processing technologies have been born. Among them, rapid prototyping technology characterized by discrete accumulation forming and CNC milling technology characterized by removal processing are the most widely used. This type of technology is omitted. The traditional wooden mold manufacturing has broken through many obstacles of the traditional sand casting process and greatly reduced the design and manufacturing constraints. Among them, the selective laser sintering technology is the most typical application based on the principle of discrete accumulation , which can realize the overall precise preparation of sand molds without being restricted by the complex shape of parts, without any fixtures, and can accurately transform CAD models. It is a solid prototype and provides a good technical way for the precision casting of complex, thin-walled and integral castings, especially in the preparation of sand molds with complex internal cavity runners and three-dimensional cross-channel slender pipes. The superiority of . However, there are still some defects. The manufacturing process requires layer-by-layer sintering. The sintering and forming time is long, the efficiency is low, and there is a step effect, and it is also limited to the space of the forming equipment and the forming speed, and it is difficult to produce large sand molds at one time. (Sand core), resulting in the inability to be comprehensively promoted and used in the foundry industry.

However, the moldless rapid manufacturing technology based on the processing principle of material removal can solve this problem well. This technology combines modern advanced numerical control technology with traditional casting technology, and is a brand-new sand mold (sand core) manufacturing technology method. , Is a major reform of traditional casting technology and has broad application prospects . Moldless sand mold CNC milling technology is driven by CAD models, and the sand blanks are directly processed by CNC machine tools to obtain sand molds (sand cores). The maximum size of a single sand mold obtained can currently reach 3.0m, and the dimensional accuracy of the CNC machined sand mold can be It can be improved to CT6-7 level, and the surface roughness can reach 3.2-6.3μm, which can realize the overall near forming of the complex cavity; ​​and it has the advantages of short manufacturing cycle, high precision, flexibility, and low cost, which can meet It meets the requirements of rapid and flexible market response.

At present, the number of products with casting as the final processing process is increasing, which puts forward higher requirements for its castings. However, to win the competition in the near-net shape technology, the primary problem is to further improve the surface quality of the castings, including reducing the surface roughness. And improve the dimensional accuracy, so higher requirements are put forward for the surface of the moldless CNC milling sand mold. At present, there are still some defects in CNC milling of sand molds: one is the phenomenon of chipping, collapse, cracks and fractures in the milling process, which directly cause the failure of the entire sand mold; second, there is floating sand on the surface of the processed sand mold, which leads to the casting. The surface roughness and dimensional accuracy of castings are poor. The surface quality and accuracy of milling sand molds are closely related to the processing parameters, but the research on CNC milling of sand molds is just beginning, and it is limited to the development and production of related equipment, and the performance, quality control, and numerical control of sand blanks The milling mechanism and the optimization of milling process parameters need to be further studied. At present, the number of products with casting as the final processing process is increasing, which puts forward higher requirements for its castings.

However, to win the competition in the near-net shape technology, the primary problem is to further improve the surface quality of the castings, including reducing the surface roughness. And improve the dimensional accuracy, so higher requirements are put forward for the surface of the moldless CNC milling sand mold. At present, there are still some defects in CNC milling of sand molds: one is the phenomenon of chipping, collapse, cracks and fractures in the milling process, which directly cause the failure of the entire sand mold; second, there is floating sand on the surface of the processed sand mold, which leads to the casting. The surface roughness and dimensional accuracy of castings are poor. The surface quality and accuracy of milling sand molds are closely related to the processing parameters, but the research on CNC milling of sand molds is just beginning, and it is limited to the development and production of related equipment, and the performance, quality control, and numerical control of sand blanks The milling mechanism and the optimization of milling process parameters need to be further studied.