What components does the cylinder head assembly consist of?

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.

• What are the components that make up the cylinder head structure?

• What are the thermal load requirements for cylinder head manufacturing?

• What is the structure of the cylinder head?

What are the components of cylinder head structure?

1、Basic composition.

The cylinder head has an exhaust valve seat hole, a valve guide hole and a spark plug installation hole (gasoline engine) or an injection nozzle installation hole (diesel engine). Part of the cylinder head and water jacket, in the exhaust and combustion chamber or part of the combustion chamber. If the camshaft is mounted on the cylinder head, the cylinder head also has cam bearing holes or cam bearing seats and their lubricating oil channel.

2, Structural shape.

The cylinder head is divided into three structural forms: integral, block type and monoblock type.

Note: The cylinder head has the function of closing the upper part of the cylinder and, together with the top of the piston and the cylinder wall, forming combustion

What are the thermal load requirements for cylinder head production?

The operating temperature of the bottom of the cylinder head increases as the load of the diesel engine increases and the cooling conditions deteriorate. The operating temperature is highest in the area of the nose bridge between the injector hole and the valve seat hole. There is a large temperature difference between the fire contact area and the water contact area at the bottom of the cylinder head, as well as between the center and the surrounding area of the cylinder head. According to the measurement, the temperature at the exhaust valve seat hole of a diesel engine reaches 430 °C during operation, and the maximum temperature difference exceeds 200 °C. In addition, due to the uneven thickness of each part, the complex shape and the limitation of tightening the bolts, the thermal expansion and cold contraction are greatly limited, causing a large thermal stress. Thermal stress is often the main cause of cylinder head cracking. Thermal stress is represented by σT.

What is the structure of the cylinder head?

The cylinder head is a box-shaped part with a complex structure. It is machined with intake and exhaust valve seat holes, valve guide holes, spark plug mounting holes (gasoline engines) or injector mounting holes. Also cast into the cylinder head are a water jacket, intake and exhaust ports, and a combustion chamber or part of the combustion chamber. If the camshaft is mounted on the cylinder head, the cylinder head is also machined with cam bearing holes or cam bearing seats and their lubricating oil channels.

The cylinder head of the water-cooled engine has three structural forms: integral type, block type and monolithic type. In a multi-cylinder engine, if all cylinders share one cylinder head, the cylinder head is called an integral cylinder head. if there is one head for every two cylinders or one head for three cylinders, the cylinder head is a block cylinder head; the first cylinder head is a single cylinder head. Air-cooled engines are monolithic cylinder heads.

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