During the casting process of automobile engine cylinder block, in order to effectively ensure the casting accuracy of automobile engine cylinder block, relevant enterprises and technicians should pay attention to the following points:
The first is the reasonable selection of the datum plane. In the process of casting and processing the cylinder block of automobile engine, we must make a good selection of the process datum plane. There are thousands of sizes on the cylinder block surface. If each size has a certain deviation in the specific production, there will be a large size chain, which is not allowed in the design. Based on this, in the process of automobile engine block casting, it is necessary to strictly control the position of the lower core and the size of the outer mold, and determine the blank processing positioning point through the processing benchmark, so as to make the design reasonable and consistent.
The second is the correct selection of shrinkage. Under the influence of casting liquid composition, the casting accuracy of automobile engine cylinder block also has certain control difficulty. Therefore, the reasonable selection of casting liquid shrinkage is also a very important content. For the most common high-pressure molding, the shrinkage of the casting liquid in the length direction should be 0.8% and the shrinkage of the casting liquid in the height direction should be 1%.
The third is the improvement of tooling manufacturing accuracy. For the current NC machine tool processing, the tooling manufacturing accuracy should be controlled at 0.03mm, especially for the mass-produced automobile engine cylinder block castings. In the casting of automobile engine cylinder block, because the misalignment problem will have a negative impact on the manufacturing accuracy of tooling, technicians must check the misalignment regularly, so as to realize the effective prevention and treatment of misalignment problem.
The fourth is the reasonable selection of the water jacket core, which is the key to ensure the uniform thickness of the cylinder wall. On the water jacket core, a small chip of the water hole of the cylinder head barrel should be made, and the core head should be strictly controlled; The water jacket core and the cylinder top core shall be glued and fixed with bolts. The process holes reserved at the two ends of the water jacket core shall be larger. In this way, the casting accuracy of automobile engine block can be well controlled.