Large and medium-sized engine is an important power source of mechanical equipment, which is widely used in automobile, ship, engineering machinery, agricultural machinery and other fields. It is an indispensable part of human industrial and agricultural production activities, and has important strategic significance for the development of China’s national economy and national defense and military industry. Taking the automobile industry as an example, with the rapid development of China’s automobile localization process, the car ownership shows a growing trend, and China will become the world’s largest automobile production and sales country. The rapid development of domestic and foreign automobile market will certainly stimulate the great development of market economy and stimulate the strong demand of automobile engine block market.
As one of the key parts of the engine, the cylinder block collects the functions of combustion, transmission and cooling, and some functions of the engine combustion chamber are also completed here. Cylinder block is composed of many cavities with uneven wall thickness and complex structure. It is one of the most complicated castings in engine casting, which concentrates a large number of core manufacturing technologies. The quality of cylinder block casting is one of the important factors restricting the engine performance, which plays a key role in the performance indexes of the engine. It can be said that the manufacturing technology of cylinder block and cylinder head reflects the ability of engine manufacturing.
However, at present, China’s engine manufacturing weaknesses are mainly manifested in the following aspects:
(1) The continuity and perfection of pouring and riser technology for engine cylinder block is insufficient. There are many kinds of experiences and theories to guide the casting production of cylinder block, such as sequential solidification and simultaneous solidification theory, torricli small hole outflow theory and large hole outflow theory, all of which play a role in varying degrees, and the resultingis very different. At present, cylinder casting generally depends on the experience of workers, and the experience of industrial workers is different, which makes it difficult to popularize good casting technology. At the same time, the process of repeated debugging will become unstable due to the change of cylinder manufacturing requirements or conditions.
(2) The degree of digitalization and informatization of engine block casting process is low. In China, the casting process of engine cylinder block is mostly completed by manual work, and the digital and information level of casting process is low due to the lack of digital gating and riser system. However, western developed industrial countries attach importance to the digitization and informatization of casting process, and have realized the technical application in the industrial field. For example, German winter company uses the artificial view technology to automatically identify the unqualified sand mold by moire method, so as to realize the information management of the production process.
(3) The casting defect rate of engine cylinder block is high. Due to the backward manufacturing technology and the lack of information technology in the casting process, there are many kinds of internal and external defects in cylinder block iron castings. The waste products of engine block in our country are 5% – 10%, which is twice as much as that in foreign countries. The defects of cylinder block not only affect the surface roughness and appearance of castings, but also restrict the compactness, corrosion resistance, crack propagation resistance and mechanical properties of castings.
Therefore, it is very important to analyze and summarize the gating and riser technology of engine block, summarize the design principles of typical gating and riser technology, and establish digital gating and riser process system relying on computer technology, so as to realize the application of digital and information technology in cylinder block casting industry, and promote the process of digitalization and informatization.