Cylinder and the cylinder head is complementary to each other, and a pair of is inseparable from the theme. So what is the cylinder head. The role of the cylinder cover is sealed cylinder, form the combustion space, together with the piston and the effect of high temperature and high pressure gas. Cylinder cover gas under physical and tighten bolts of cylinder caused by the mechanical load, to protect the cylinder will not be hurt. Also due to contact with high temperature gas under high thermal load. In order to ensure good sealing of cylinder, cylinder head can not damaged, not deformation. For this purpose, the cylinder head should have sufficient strength and rigidity. Like cylinder, in addition to want to know what is the cylinder head more major is to understand what's the role of the cylinder head.
Cylinder head is complex box parts. On its inlet and exhaust valve seat hole machining, valve guide hole, the spark plug mounting hole (gasoline engine) or injector mounting holes. Within the cylinder head casting also has a water jacket, into the exhaust duct and part of the combustion chamber and combustion chamber. If the CAM shaft is installed on the cylinder head, cylinder head CAM bearing hole is still processing or CAM bearing and lubricating oil. So, it is because of this kind of structure form, it is the function of sealing gas, form the combustion space, together with the piston and the effect of high temperature and high pressure gas. Cylinder head work are: (1) cylinder head under high temperature and high pressure gas, bear a lot of bolt pre-tightening force, leading to mechanical stress. (2) the cylinder head structure is complex, serious uneven temperature field, thermal stress lead to big, serious can cause crack of cylinder head and the overall deformation. Therefore the design requirements of cylinder head is (1) has enough stiffness and strength, small deformation work, guarantee the seal. (2) the reasonable decorate the combustion chamber, valve, airway, guarantee the working performance of engine. (3) good manufacturability, uniform temperature field as far as possible, reduce the thermal stress, avoid cracking phenomenon. In mechanical design, for each of the parts design and processing, understand the role of the parts, it is easy to know what is the cylinder head.