Abnormal sounding of agricultural machinery engines is mainly caused by the loosening, improper adjustment or improper use of internal mechanical parts. This indicates that the engine has major or minor faults and should be diagnosed promptly and effective maintenance measures should be taken. Guangdong Jia Mei Biological Technology Co.Ltd , https://www.jaymeimask.com
First, the initial diagnosis, determine the impact of abnormal sound on the engine In many complex engine sounds, first of all should determine what is the normal sound, which is abnormal noise. Which of the abnormal noises have little effect on the working conditions of the engine is allowed to exist temporarily; which ones are not allowed to continue to exist, they must be eliminated immediately, otherwise it is more likely to cause greater harm.
1. If the sound is slightly simple when the engine is running at a low speed, the roar sounds even and smooth during high-speed operation, and it appears as a smooth transition during acceleration and deceleration, which is a normal sound.
2. If the sound is only present at idle speed, it will disappear after the speed is increased. There will be no noticeable change in the sound during the entire use. This is an unusually noisy sound that allows for temporary existence and should be repaired at the appropriate time.
3. If the sound is suddenly accelerated or suddenly decelerates, and when the engine does not disappear during the medium and high-speed operation, and the organic parts vibrate at the same time, then this is an abnormal sound that is not allowed to continue to exist and should be checked immediately. Explain why and exclude it.
4. If the sound suddenly appears during the operation, and if it is more violent, it should not be continued or diagnosed by trial-and-error. Instead, it should be immediately shut down for inspection. Generally, the bottom shell is removed first, and then the cylinder head and the valve chamber cover are removed.
Second, careful analysis, and then determine the location, cause and degree of abnormal noise on the emergence of abnormal sound and the continuous existence of the time, abnormal sound generally exist in: idle or low-speed operation period, during high-speed operation or the entire driving period.
1. For abnormal noise during idle or low speed operation (1) First, check whether the abnormal noise is related to the working cycle, and further determine the location of the fault. If there is an association, it indicates that the failure occurred in the crank linkage mechanism or the valve distribution mechanism. According to the frequency of abnormal sounds, a preliminary determination can be made. All the sounds caused by the crank connecting rod mechanism are emitted by one working cycle twice, and the sound caused by the gas distribution mechanism is emitted once by one working cycle. Therefore, the crankshaft bearing Frequencies of abnormal sounds at places etc. are low, and frequencies of abnormal sounds at valves, etc. are high.
(2) Gradually increase the engine speed, hear whether there is any abnormal sound, and judge the degree of loss of the moving parts according to the change of the abnormal sound with the speed.
(3) Attention should also be paid to observing the effect of engine temperature changes on abnormal sound.
(4) For a multi-cylinder engine, check whether the abnormal sound and the cylinder position are related by using a single-cylinder cut-off method. If there is a noticeable change in abnormal noise after a cylinder breaks the oil and breaks the fire, it means that the fault is in this cylinder; if there is no obvious change in the abnormal sound after a cylinder breaks the oil and breaks the fire, it means that the abnormal sound is not related to the cylinder position.
Through the diagnosis of the above-mentioned several processes, the relationship between abnormal noise and engine load, work cycle, rotation speed and temperature can be basically ascertained. If the abnormal sound matches certain abnormal sound characteristics, a final diagnosis can be made.