Technical Requirements of Precision Casting
Veröffentlichte Zeit:2020-03-06 00:00
For example, sand casting, mass production factories should create conditions to adopt advanced molding and core making methods. The production line of the old-fashioned shaker or shaker molding machine is not high enough, the labor intensity of the workers is large, the noise is large, and it is not suitable for the requirements of mass production, so it should be reformed step by step. For small castings, the production line of high-pressure molding machine without box with horizontal or vertical parting can be used.
The production efficiency of solid molding is high and the floor area is small. For medium-sized castings, various production lines of high-pressure molding machine with box and air impact molding line can be selected to meet the requirements of fast and high-precision molding production line. The core making method can be selected as: high-efficiency manufacturing of cold core box, hot core box, shell core, etc Core method.
Resin self hardening sand molding and core making can be considered for medium batch large castings.
For heavy castings produced in a single small batch, manual modeling is still an important method. Manual modeling is flexible to meet various complex requirements and does not require many process equipment. Water glass sand mold, VRH water glass sand mold, organic ester water glass self hardening sand mold, clay dry mold, resin self hardening sand mold and cement sand mold can be used; for heavy castings produced by single piece, pit molding method has low cost and fast production. It is more suitable to adopt multi box and split box modeling for mass production or long-term production of set shaped products. Although the investment of mold and sand box is high, it can be compensated from saving molding time and improving product quality.
Low pressure casting, die casting, centrifugal casting and other casting methods are only suitable for mass production because of the high price of equipment and mould.
The condition method should be suitable
For example, it is also used to produce large-scale machine bed and other castings. Generally, the core forming method is used instead of making patterns and sand boxes. In other factories, the sand box forming method is used to make patterns. Different enterprises have different production conditions (including equipment, site, staff quality, etc.), production habits, and accumulated experience. According to these conditions, we should consider what products are suitable for and what products are not (or are not) suitable for.
Accuracy requirements and costs
Different casting methods have different precision, different initial investment and productivity, and different final economic benefits. Therefore, in order to achieve more, faster, better and less, we should take into account all aspects. The initial cost estimation should be made for the selected casting method to determine the casting method with high economic benefit and guarantee the casting requirements.
Although the development of China's foundry industry is in a relatively difficult period, but in the long run, there is still some hope for the development of China's precision casting industry, the market demand has slowly started to pick up, and with the strong strength of China's foundry industry development, I believe that China's foundry industry will make gratifying achievements.
Experts said that to fundamentally improve the level of casting technology, we must do the following four points: first, develop simulation technology, improve the accuracy of prediction, strengthen process control, and improve the yield. The problem of regularity is not well grasped, which affects the yield of mass production. Second, the combination of production, learning and research. In addition to the enhancement of innovation consciousness and R & D ability, the independent innovation of enterprises also needs to pay attention to and strengthen the combination of production, learning and research, which is mainly composed of precision casting enterprises. Third, attach importance to material research and development. Materials are the foundation of industry, and there is still a lot of work to be done at present. In the field of Aeronautics and Astronautics, the research and smelting technology of alloy materials, especially superalloys, need to be improved, and there is a big gap with foreign countries. Fourth, pay attention to the improvement of equipment technology. The technology is mainly about equipment. Many key equipment, such as some directional solidification equipment, are mainly imported. Therefore, the research and development of precision casting equipment is still the focus.