Bitzer 4VC Piston is an important part of the crank connecting rod mechanism. The main function of gas is to bear the combustion gas pressure and inertial force, and transmit the combustion gas pressure to the connecting rod through the piston pin to push the crankshaft to rotate to do external work. In addition, the piston is an integral part of the combustion chamber.

The Bitzer 4VC Piston is the toughest working part in an internal combustion engine. Both the gas pressure and inertial force acting on the piston change periodically, and the gas pressure acting on the piston at the moment of combustion is very high. For example, the maximum combustion pressure of a supercharged internal combustion engine can reach 14-16MPa. Moreover, the piston is also subjected to the periodic impact of the side pressure when the connecting rod is inclined. Under the combined action of the gas pressure, the reciprocating inertia force and the side pressure, the piston may be deformed, the piston pin seat is cracked, and the side of the piston is worn. It can be seen that the piston should have sufficient strength and rigidity, and the mass should be light.

The top of Bitzer 4VC Piston is in direct contact with high-temperature gas, the temperature of the top of the piston is very high, and the temperature difference between each part is large. The top of the diesel engine piston is often arranged with a pit-shaped combustion chamber, which increases the actual heating area of ​​the top and makes the heat load more serious. High temperature will inevitably cause the strength of the piston material to decrease, the thermal expansion of the piston will increase, and the normal clearance between the piston and the cylinder wall will be destroyed. In addition, the thermal stress caused by the uneven cooling and heating is easy to cause fatigue thermal cracking on the top of the piston. Therefore, it is required that the piston should have sufficient heat resistance and good thermal conductivity, and a small coefficient of linear expansion. At the same time, appropriate measures are taken on the structure to prevent excessive thermal deformation.

Bitzer 4VC Piston has high moving speed and working temperature, and poor lubrication conditions, so friction loss is large and wear is serious. It is required to have good friction reduction or special surface treatment.