The 3-D Finite Element Analysis And Temperature Field Experimental Research Of Turbocharged Diesel Engine Piston

The piston, as one of the key spare parts of the internal-combustion engine, its working condition concerns working dependability and use durability of high-speed internal-combustion engine directly, influences the emission performance of the internal-combustion engine directly at the same time. The structure of piston and its working environment are very complicated. In working condition, the piston stands periodic load, such as high gas-pressure, inertia-pressure, side direction pressure and factional force, which produced by combustion gas pressure strength and high speed reciprocating, and produces mechanical stress and distortion. The burn of high-pressure gas produced high temperature makes piston top and whole temperature of piston very high, even the temperature distribution is asymmetry, causing the piston to produce hot stress and hot distortion. Hot load and mechanical load coupling make piston to produce crackle, piston-ring glued and scuffing of cylinder bore and so on. So during the course of designing, calculating and analyzing the piston temperature field, force field and coupling load that hot and mechanical load act on together in conformity with the force field, finding out the hot load state of the piston and comprehensive stress distribution situation, so to improve the piston and its working dependability is significant.This paper adopted rigidity-plug temperature measurement method to test key dot temperature of piston surface under different working conditions of the 4100 model supercharged diesel engine and supercharged intercooling diesel engine, has obtained piston surface temperature value of key dot under different working conditions, analyzed relation of working temperature of piston vary with the rotational speed of internal-combustion engine. Through the temperature value that is measured, have calculated the piston temperature field and hot stress and distortion under the declared working conditions of the 4100 model supercharged diesel engine and supercharged intercooling diesel engine, and has compared with and analyzed the influence which form of combustion chamber and combustion chamber position to the temperature field of the piston and hot stress distributing and distortion. Meanwhile, this paper also calculated and analyzed mechanical stress field and distortion, and coupling-stress field and distortion that hot and mechanical load act on together in conformity with the force field, which of the piston under the declared working conditions of the series supercharged diesel engines, and compared with and analyzed the influence which form of combustion chamber and combustion chamber position to the coupling-stress field distributing and distortion of the piston. In the end, this paper carries on intensity prediction to the series supercharged diesel engines piston, have put forward the corresponding corresponding-measure.Through the finite element analysis and temperature field experimental research, we have got the results of the temperature field and stress field and distortion of the series diesel engines, have offered certain theoretical foundation for development and improvement of the series supercharged diesel engines piston, also have offered the parameter for the finite element analysis and computation of other series of products which this factory produces at the same time .