The function of the cylinder head of a car engine is to close the upper part of the cylinder, and together with the upper part of the piston to form the combustion chamber. cylinder head structure is complex, usually using foot iron or aluminum alloy material manufacturing, for certain engines, cylinder head structure varies, but there are many common points. cylinder head and the cylinder body combined, the level of the pit is part of the combustion chamber, in the cylinder head to the processing of valve seat.

The function of the cylinder head is to seal the cylinder, form a combustion chamber with the piston, and resist the action of high-temperature and high-pressure gas. The cylinder head is subjected to mechanical stresses caused by gas forces and cylinder bolt tightening, as well as high thermal stresses due to contact with high-temperature gas.

The cylinder head should have sufficient rigidity and strength, because the cylinder head must withstand the mechanical load caused by the gas force and the tightening of the cylinder bolts, and also because it must withstand the thermal load caused by high temperature and high pressure.

The cylinder head is equipped with intake and exhaust ports, valve seats, valve guides into the hole, also with cooling water channels and lubricating oil channels on the cylinder head of gasoline engines with spark plug holes, diesel engine cylinder head with injection holes.

The cylinder head is part of the gas distribution mechanism of an internal combustion engine, and is mainly used to close off the top of the cylinder to form the combustion chamber, as well as the camshaft and rocker arm shaft, and the intake and exhaust pipes. Burning the fuel in the cylinder generates the kinetic energy to move the piston back and forth in the engine cylinder, which drives the connecting rod connected to the piston and the crank connected to the connecting rod to make a reciprocating circular motion around the center of the crankshaft and power output.

CNC machining refers to the machining which is carried out by CNC machine tool machining equipment. Since CNC machining is controlled by computer after programming, CNC machining has stable machining quality, high machining accuracy, complex surface and high machining efficiency.