The piston of an automobile engine is one of the main components in the engine. It is composed of a piston ring, a piston pin and other components to form a piston group, and a cylinder head and the like to form a combustion chamber, which is subjected to gas force and transmits power to the piston pin and the connecting rod. The crankshaft to complete the working process of the internal combustion engine. Since the piston is in a harsh working environment of high speed, high pressure and high temperature, it is necessary to consider the smooth and durable operation of the engine. Therefore, the piston must also have sufficient strength and rigidity, good thermal conductivity, high heat resistance and small expansion coefficient. (The size and shape change are small), the relative density is small (light weight), wear resistance and corrosion resistance, and the cost is low. Due to the high and high requirements, some of the requirements are contradictory, it is difficult to find a piston material that can fully meet the requirements. The pistons of modern engines are generally made of aluminum alloy. Because aluminum alloys have the advantages of small density and good thermal conductivity, they have the disadvantages of large expansion coefficient and poor high temperature strength. These shortcomings can only be achieved through reasonable structural design. To meet the requirements of use. Therefore, the quality of the car engine, not only depends on the materials used, but also depends on the rationality of the design.
There are tens of thousands of parts in the car, ranging from crankshafts to gearbox bodies to small spring washers and bolt nuts. Every part has its function, like the “small point” of the piston ring, it looks simple in shape, the weight is very light, and the price is very cheap, but the effect is not trivial. If it is lacking, it will not be able to move the car. Even if it has a small problem, the car will be abnormal, or it will consume a lot of fuel or be underpowered. In the cooperation of the entire piston group and the cylinder, the piston ring actually contacts the cylinder wall in the piston ring, which fills the gap between the piston and the cylinder wall to close the combustion chamber, so it is also the most wearable part in the engine. . The piston ring is generally made of cast iron and has a certain elasticity. The cross section has various shapes and the surface is coated to increase the running-in performance.