The Design And Temperature Control Of The General Engine Forced Air Cooling System

In the five years of development work in general found in engine technology, the reliability of the engine market share is to ensure that the most important aspects. Statistics for many years the quality of experimental data and customer feedback, the problems caused by the temperature about 23% of all issues. Temperature is the key to engine life and reliability factors, serious damage will be a variety of high temperature lubrication of links, and lower mechanical strength of the parts, increasing the amount of pollutants discharged. Although many products through the imitation of foreign products or make some small changes can be accomplished, but the details of materials and products used in handling the problem, at this stage the overall temperature of the high domestic general engine, spark plugs (leeward side) The highest temperature can reach 250℃~280℃, and even test also the case have more than 300℃, the maximum temperature of the oil are 130℃~150℃range. With foreign counterparts (HONDA, Kawasaki, B & S, KOHLER, etc.) compared to our general engine temperature control and there is still a gap between them.At this stage, the engine cooling system of domestic and foreign common basic structure with air-cooled centrifugal force. The centrifugal force air through the structure of the heat sink parameter, the cooling air system and its subsidiary bodies adjust the experimental data before and after contrast, concluded a universal approach to design the engine cooling system and method. Study has two parts, the first part of a flat plate heat sink module of the louvers and the heat sink and heat sink from the root of C R on the cooling effect of rounding effects; the second part of a vertical displacement of 452CC shaft engine-based models to explore the arrangement of the shroud and different impeller, wind system cooling effect. By comparing the experimental data, the louvers and the heat sink from C mainly affects the heat sink coefficientαchanges; heat sink roots rounding the roots of R will affect the heat sink and thermal distribution of heat flow values; engine shroud arrangement different ways along the circumference of the cylinder will affect the temperature distribution and uniformity; and different impeller, wind system will directly affect the overall temperature of the engine, including engine oil temperature, cylinder head temperature.Through this study, data analysis, reasonable wind deflector and heat sink from C, is too large heat sink down roots round R, a reasonable layout of the engine shroud and appropriate different impeller, wind system can effectively reduce engine temperature, reduce the cylinder temperature difference along the circumference. Improve the general reliability of the engine has an important role.