The cylinder head gasket, also known as the “cylinder bed,” is positioned between the cylinder head and the cylinder block. Its primary function is to fill microscopic pores and gaps between the cylinder block and the cylinder head, ensuring a reliable seal at the mating surface. This, in turn, guarantees the sealing of the combustion chamber, preventing air leakage from the cylinders and water leakage from the cooling jacket.
Functions of the Cylinder Head Gasket:
The core role of the cylinder head gasket is to ensure sealing between the cylinder block and the cylinder head, preventing the leakage of high-pressure gases, coolant, and engine oil. Its specific functions are as follows:
Sealing Effect:
Filling Microscopic Gaps: The gasket compensates for surface roughness and irregularities at the mating interface between the cylinder block and the cylinder head through its elastic material, maintaining high-pressure sealing in the combustion chamber and preventing air leakage.
Isolating Fluid Passages: It prevents coolant and engine oil from leaking during their circulation between the cylinder block and the cylinder head, ensuring the normal operation of the engine’s cooling and lubrication systems.
Material and Performance Requirements:
Pressure and Heat Resistance: The gasket must withstand high engine temperatures (exceeding 200°C) and combustion pressures. Common materials include metal-asbestos composites or all-metal constructions, which offer corrosion resistance and minimize deformation.
Elastic Compensation: The gasket maintains sealing performance through elastic deformation when the cylinder head undergoes thermal expansion or mechanical stress, avoiding sealing failures caused by deformation.
Extended Effects:
Thermal Insulation and Vibration Damping: Some gasket designs incorporate heat-resistant materials to reduce heat transfer to the cylinder head while also damping engine vibrations and reducing noise.
Failure Symptoms: If the gasket is damaged, it may lead to engine power loss, coolant mixing with engine oil (emulsification), water discharge from the exhaust pipe, and other fault phenomena.
As internal combustion engines continue to evolve with increasing thermal and mechanical loads, the sealing performance of the cylinder head gasket becomes increasingly critical. The requirements for its structure and materials are as follows:
Sufficient strength to withstand high temperatures, high pressures, and corrosive combustion gases.
Heat resistance to prevent damage or deterioration.
Corrosion resistance to ensure longevity.
Elasticity to compensate for surface irregularities and maintain sealing.
A long service life to ensure reliable engine operation.
Post time: Apr-25-2025