Second, the cylinder head

The cylinder head is also called a cylinder head mounted on the upper portion of the cylinder block with head bolts on the cylinder body. Its role is to seal the upper portion of the cylinder constituting the combustion chamber. It also has an internal cooling water jacket, cooling water, cooling water bore holes of the end surface of the cylinder block in communication, in order to use recycled water for cooling the high temperature portion of the combustion chamber.

The cylinder head structure of a diesel engine with a different form. Small diesel engines with integral or massive structure, coming across all cylinders diesel engine cylinder head (such as the 4125 model, 12V150 diesel engine) or two three cylinders of the cylinder head (eg 12V135 diesel engine, Cummins NTA series diesel engine) combined cast one, with a compact, can enhance the body's rigidity characteristics. Large single cylinder diesel engine adopts cover (eg Z12V19OB Diesel) a separate removable so you can change and repair, series universal, good sealing performance.

Four-stroke diesel engine cylinder head structure shown in Figure 2.17.

The cylinder head is usually of high-strength cast iron blanks, and then made machined. Gas Cummins Diesel NTA Series

Cylinder head structure assembly. It's inside the intake and exhaust channels, cooling water and lubricating oil channel, as well as for the installation of the cylinder head injectors, intake valves, exhaust valves, valve springs, valve seats, valve guides and other parts rocker holes and threaded holes.

The cylinder head is a cylinder-type structure, a rocker, a gasket between the cover and the sealing chamber, the cylinder head to prevent leakage. Set with a "wet" water jacket injector mounting hole. When working in the body of the water jacket cooling water circulating through the water jacket, the gap between the outer wall of the cylinder head, so to obtain good cooling nozzle. Prevent leakage, in the upper part of the car there is a water jacket ring groove for installing a rubber O-ring seal in water use.

In order to ensure the tightness of the cylinder head, cylinder block between the cylinder head and cylinder head gasket joints installation. Cylinder head gasket is made with copper sandwiched between asbestos, with some flexibility and strength. It prevents leaks, leaks, spills great relationship, its thickness and extent of the work will also affect the performance of the diesel engine compression ratio and, therefore, should pay attention to the use and maintenance of diesel engine cylinder head gasket to ensure a good selection by the original thickness of the replacement.