Cylinder HeadThe lid of the engine and the parts that close the cylinder, including the water jacket and valves and cooling plates.The cylinder head is cast iron or aluminum alloy, which is the installation base of the valve mechanism, and is also the sealing cover of the cylinder, and the top of the good cylinder and piston constitutes the combustion chamber. Many have adopted structures that integrate camshaft support seats and tappet guide holes with cylinder heads.The damage phenomenon of the cylinder head is mostly the deformation of the sealing plane of the cylinder head and the cylinder bore (so that the seal is damaged), the crack of the inlet and exhaust valve seat holes, and the loss of the spark plug installation thread. In particular, the cylinder head poured with aluminum alloy has a lower material hardness and relatively poor strength, and is easy to deform and damage, so the consumption is more than that of cast iron.

1. Working conditions and requirements of cylinder headThe cylinder head is subjected to the mechanical load caused by the gas force and the tightening of the cylinder head bolts, and at the same time it is subjected to a high thermal load due to the contact with the high temperature gas. In order to ensure good sealing of the cylinder, the cylinder head must neither be damaged nor deformed. For this reason, the cylinder head should have sufficient strength and rigidity. In order to make the temperature distribution of the cylinder head as uniform as possible and avoid thermal cracks between the intake and exhaust valve seats, the cylinder head should be well cooled.2. Cylinder head materialCylinder heads are generally made of high-quality gray cast iron or alloy cast iron, and gasoline engines for cars mostly use aluminum alloy cylinder heads.3. Cylinder head structureThe cylinder head is a box-shaped part with complex structure. It is processed with intake and exhaust valve seat holes, valve guide holes, spark plug mounting holes (gasoline engine) or fuel injector mounting holes (diesel engine). Also cast in the cylinder head are the water jacket, the intake and exhaust ports and the combustion chamber or part of the combustion chamber. If the camshaft is installed on the cylinder head, the cylinder head is also processed with a cam bearing hole or a cam bearing seat and its lubricating oil passage.