HS code mapping for re-importation

Analysis of the difference and HS code mapping for re-importationfunction between the engine cylinder head and the cylinder block The engine is one of the core components of the car, and the cylinder block and cylinder head of the engine are an important part of the engine.They take on different important responsibilities in the working process of the engine. This article will analyze the differences and functions of the engine cylinder head and cylinder block. I. Definition and function of cylinder block and cylinder head. The engine cylinder block is the main part of the engine and is the container of each cylinder volume. It directly comes into contact with and bears the effect of high temperature, high pressure and sealed gas generated by combustion in the cylinder. In addition to being a container for piston movement, the cylinder block also bears the pressure in the cylinder, fixes the piston and connecting rod, and ensures the tightness of the cylinder. The engine cylinder head is a part that covers the cylinder head, also known as the valve chamber cover or valve cover. The cylinder head is used to close the valve chamber to ensure the normal operation of the valve, camshaft and cylinder head mechanism; at the same time, the cylinder head can also play a role in reducing valve noise and valve leakage. The engine cylinder head still needsIt is necessary to withstand the rotation of the valve mechanism during the normal operation of the engine, and at the same time form a cylinder block head with the cylinder block to ensure the tightness of the cylinder. II. The material of the cylinder block and cylinder head The material of the cylinder block and cylinder head is usually cast iron or cast aluminum. In the production of modern cars, due to the increasing requirements for engine quality, performance, weight and fuel consumption reduction, the material of cast iron has been gradually replaced by cast aluminum in history. Compared with cast iron engines, cast aluminum engines have the advantages of light quality, good heat dissipation, convenient processing and high maintenance performance. The density of aluminum is relatively small, so its weight is relatively light, and its thermal conductivity is high, which is not greatly affected at high temperatures, so it is more suitable for high-speed rotating engines. III. The difference between the cylinder block and the cylinder head 1. Structural differences. From the structural point of view, the shape and internal structure of the cylinder block and cylinder head are also different.The interior of the cylinder block is relatively complex, including the cylinder and oil line, waterway, gas line, etc. And the cylinder head is much simpler. The cylinder head usually has a valve and an ignition plug, because it needs to be exposed to the cylinder, so it has to provide a certain degree of heat resistance. Two. Functional differences In the process of engine operation, the main function of the cylinder block is to use gas pressure to promote the piston movement, thus driving the crankshaft to rotate to generate power. The cylinder head mainly serves to seal the valve chamber of the cylinder head, so that the valve and oil flow to the corresponding pipeline. At the same time, it also seals the cylinder to protect the piston and the corresponding piston ring relatively well. IV. The power and performance of the cylinder block and cylinder head of the engine depends not only on the quality of the cylinder block and the cylinder head, but also crucial. Due to the high temperature, high pressure, etc. involved in the operation of the engineIn complex environments, the close cooperation between the cylinder block and the cylinder head has a great impact on the engine power, service life, etc. Therefore, when manufacturing cylinder blocks and cylinder heads, strict size matching and processing accuracy control are required. In a word, the cylinder block and the cylinder head have a clear identity in the engine and bear different important responsibilities. Of course, the degree of cooperation between the cylinder block and the cylinder head is also very important. Through the analysis of the differences and functions of the cylinder block and cylinder head, we can better understand the working principle and key points of the engine, which is also more instructive for daily repair and maintenance.

Contact Us
Phone：020-83484653