Working condition of piston

Working condition of piston

The piston works under high temperature, high pressure, high speed and poor lubrication. Piston is directly in contact with high temperature gas, instantaneous temperature can reach more than 2500K, therefore, the heat is serious, and the heat dissipation conditions are very poor, so the piston working temperature is very high, the top up to 600 ~ 700K, and the temperature distribution is very uneven; The top of the piston bears great gas pressure, especially the maximum working stroke pressure, gasoline engine up to 3 ~ 5MPa, diesel engine up to 6 ~ 9MPa, which makes the piston impact, and bear the role of side pressure; The piston reciprocates in the cylinder at a very high speed (8 ~ 12m/s), and the speed is constantly changing, which produces a great inertia force, so that the piston is subjected to a great additional load. Working under such harsh conditions, the piston will deform and accelerate wear, as well as generate additional loads and thermal stresses, and be subjected to chemical corrosion by gas.
Piston inspection is mainly the measurement of skirt diameter, piston ring groove height and piston pin seat hole size:
The selection of piston should be determined according to the repair size of the cylinder. Usually the larger size is marked on the top of the piston;
② In the same series of fish, the structure of the piston is not necessarily the same, so in the purchase of piston, must choose the corresponding type of piston according to the type of engine. In the same engine, should choose the same brand, the same group or the same product code piston; The same model must use the piston of the same product code, to ensure that the difference in diameter and quality of the piston is not more than the original factory. Otherwise, it will cause engine combustion poor, rough work, economic and power decline and other failures. Therefore, when selecting the piston, the corresponding piston model must be selected according to the type of engine.