A Study on the Detection of Non-combustion Cylinder of the Diesel Engine for Construction Machinery. An application of rms analysis of acceleration waves.

Abstract

Big scale construction machinery is absolutely necessary for the mineral resources development and various construction works. Troubles of the machinery give serious losses in the efficiency of operations and also in financial proceeds. In this meaning, machinery maintenance is very important for mining and construction works. Early diagnosis of the machinery is especially important to prevent a serious damage. Recently, diesel engine applied to excavation machinery are highly improved not to discharge exhaust gases of high concentration and to achieve high energy efficiency. However, a diesel engine involving non combustion cylinder has high probability to breakdown in a short time when the engine is used without any maintenance works.In this study, autocovariance of acceleration waves of cylinder block was calculated to obtain the period of revolution, and the combustion period of each cylinder was determined. Then rms value corresponding to each combustion period was calculated. Probability of overlapped area of two curves of normal distribution, which were obtained from rms values of normal and non combustion states respectively, was calculated. It was confirmed that non combustion cylinder of a diesel engine of V-12 type could be judged clearly using the relative intensity curve of the probability. This judgement method is considered to be superior to traditional methods where more than several numbers of accelerometers were used, especially from the viewpoint of simplicity.

The detection of a misfiring cylinder of diesel engines in excavation machinery using ALM analysis

“…Figure 1 shows a schematic illustration of the proposed monitoring system. In a previous work (Kawamura et al 2001), data transfer from a remote location was successfully achieved. In this study, ALM analysis was used to carry out real-time monitoring.…”

“…The results of wavelet transformation on the acceleration waveform of a diesel engine can be expressed as the time -frequency map of the wavelet transform value (Kawamura et al 2001). Figure 6 shows these data at cylinder No.…”