Method for recognizing ignition top dead center of first cylinder of four-stroke diesel engine and detection device thereof

Abstract

The invention provides a method for recognizing the ignition top dead center of a first cylinder of a four-stroke diesel engine. The method for recognizing the ignition top dead center of the first cylinder of the four-stroke diesel engine comprises the steps that a magnetic enhancing element is embedded in a gear tooth, corresponding to the top dead center of the first cylinder, of a flywheel ring gear of a crank shaft of the diesel engine, so that a first induced voltage signal which is abnormally enhanced is obtained when the gear tooth passes a rotation speed sensor; a magnetoelectric sensor is arranged at the end of a rocker arm of a vent valve of a valve mechanism of the first cylinder of the diesel engine, so that a mutative second induced voltage signal is obtained when the position of the rocker arm is changed suddenly; the time for ignition of the top dead center of the first cylinder is judged by analyzing the relative positions where the first induced voltage signal and the second induced voltage signal are generated. The method for recognizing the ignition top dead center of the first cylinder of the four-stroke diesel engine has the advantages that the method is simple and easy to realize, the judgment result is accurate, detection cost and detection time are saved, and powerful support is provided for positioning a fault of the diesel engine. The invention further provides a detection device used for the method for recognizing the ignition top dead center of the first cylinder of the four-stroke diesel engine.

Description

technical field [0001] The invention relates to the technical field of diesel engines, in particular to a method for accurately identifying the ignition top dead center of a first cylinder when monitoring the instantaneous rotational speed of a crankshaft of a diesel engine. Background technique [0002] The structure of the diesel engine is complex, and many components work under the harsh conditions of high temperature, high pressure, high load and strong vibration, which makes the failure rate of the diesel engine high and the maintenance cost is very high. Statistics show that among the various operating costs of diesel engines, the expenditure on maintenance reaches 15-30%. Moreover, once a failure occurs, it will also affect the normal operation of the entire mechanical system, directly or indirectly cause huge economic losses, and even endanger personal safety. With the widespread use of diesel engines and the development of modern science and technology, the traditi...

AI Technical Summary

Problems solved by technology

The gear tooth position corresponding to the top dead center of the first cylinder is usually marked on the flywheel ring gear, and another set of detection system can be set up to detect the gear tooth position to judge the top dead center of the first cylinder. The space is limited, and it is very difficult to add an additional detection system; in addition, in each working cycle of a four-stroke diesel engine, the piston of the first cylinder passes through the top dead center twice, which makes it difficult to identify and judge the top dead center of the first cylinder’s ignition.

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