Structure and function of cylinder cover(cylinder head)

The cylinder cover (Cylinder Head) engine cover and cylinder parts closed, including the water jacket and the valve and the cooling fins.

Cylinder head is made of cast iron or aluminum alloy casting, the valve body is installed base, but also the seal of the cylinder cover, the cylinder and the piston top of the combustion chamber. Many have used the camshaft support structure and tappet guide hole seat with one cast cylinder cover.

The cylinder cover is damaged to deformation of the cylinder head and cylinder hole sealing plane (the seal destruction), intake and exhaust valve seat hole crack, the spark plug is installed but thread damage. Especially with the cylinder head Aluminum Alloy pouring, because of its hardness is low, the strength is relatively poor, relatively easy to deformation and damage, so the consumption of a cast iron for many.

Structure function

1. Working conditions and requirements of cylinder head

The cylinder head bears the gas force and the mechanical load caused by the fastening of the cylinder head bolt, and is also subjected to a high thermal load due to the high temperature gas contact. In order to ensure the good seal of the cylinder, the cylinder head can not be damaged, it can not be deformed. The cylinder head should have sufficient strength and rigidity. In order to make the temperature distribution of the cylinder head as uniform as possible, avoid the thermal crack between the inlet and the exhaust valve seat to deal with the good cooling of the cylinder head.

2. Cylinder head material

Cylinder head is generally made of high quality gray cast iron or alloy cast iron, car gasoline engine is more use of aluminum alloy cylinder head.

3. Cylinder cover structure

The cylinder head is a box shaped part with complex structure. It is processed on the inlet and outlet valve seat hole, valve guide hole, spark plug mounting hole (gasoline engine) or injector installation hole (diesel engine). A part of the cylinder head is cast with a water jacket, inlet and exhaust ports and combustion chamber or combustion chamber. If the cam shaft is mounted on the cylinder head, the cylinder cover is also provided with a cam bearing hole or a cam bearing seat and a lubricating oil path.

Cylinder head of water cooled engine has 3 kinds of structure, integral, block type and single type. In a multi cylinder engine, the whole cylinder is shared with a cylinder head, and the cylinder head is called as a whole cylinder head. The cylinder head is divided into a block type cylinder cover, if one or three cylinders are covered in each of the two cylinders. If each cylinder cover, then the single type cylinder head. Air cooled engines are single type cylinder head.