What is the structure and function of a car engine cylinder block?

1. Structural composition

(1) Basic structure
The cylinder block is the basic skeleton of the engine. It is usually made of cast iron or aluminum alloy and has sufficient strength, rigidity and wear resistance to withstand the high temperature, high pressure and mechanical load during engine operation.
The cylinder block contains multiple cylinder holes, each of which is equipped with a piston. The piston is connected to the crankshaft through a connecting rod to convert linear motion into rotational motion.

(2) Main components
Cylinder barrel: The central part of the cylinder block, forming the combustion chamber
End cover: Closes the two ends of the cylinder block to provide sealing.
Piston rod and piston: The piston moves up and down in the cylinder, driving the crankshaft to rotate.
Cooling water jacket: Distributed on the outer wall of the cylinder block for heat dissipation.
Oil pan: Located at the bottom of the cylinder block, it stores engine oil and seals the crankcase.

(3) Structural form
The main arrangements of the cylinder block are in-line, V-type and horizontally opposed. Different forms affect the appearance, weight distribution and performance of the engine.
In-line: The cylinders are arranged in the front-to-back direction, which is common in small engines.
V-type: The cylinders are arranged at a certain angle, which is suitable for high-performance engines.
Horizontally opposed: The cylinders are arranged horizontally, which reduces the engine height and is suitable for compact vehicles.

(4) Material selection
The cylinder block is usually made of cast iron or aluminum alloy. Cast iron cylinder blocks are wear-resistant and corrosion-resistant, suitable for heavy-duty engines; aluminum alloy cylinder blocks are light and have good heat dissipation, suitable for high-performance engines.

2. Functions and effects
(1) Support and connection
The cylinder block is the basic structure of the engine, connecting the cylinders, crankcase and other key components to ensure the overall stability and operating efficiency of the engine.

(2) Formation of the combustion chamber
The cylinder block and cylinder head together form the combustion chamber, which is subjected to high-temperature and high-pressure combustion gas and drives the piston to move.

(3) Cooling and lubrication
The cooling water jacket in the cylinder block is used to remove the heat generated by the engine and keep the engine temperature appropriate. At the same time, the engine oil lubricates the internal parts of the engine through the oil pan.

(4) Energy conversion
The cylinder body generates high-pressure gas by burning the mixed gas, which drives the piston to move and converts chemical energy into mechanical energy.

(5) Sealing and durability
The cylinder body must have good sealing to prevent coolant leakage or combustion gas leakage. In addition, its materials and design must ensure long-term durability.