System for diagnosing the technical condition of internal combustion engines of heavy duty vehicles

Abstract

The article demonstrates the wide possibilities of using remote automated diagnostics of heavy trucks, in particular, diagnostics of Scania engines.

Based on the results of using the functions "Ensuring cylinder balance", "Cylinder balance check" and "Compression check" of the Scania Diagnos 3 & Programmer software, the parameters of the influence of individual cylinders of the DC13 164 L01 engine of the Scania R 450 A4x2NA vehicle on the value of cyclic fuel feed, torque and uniformity of rotation frequency were obtained.

The obtained measurement results indicate the existing difference in the efficiency of individual cylinders and the need to eliminate the causes of these differences. Thus, based on the results of the “Cylinder balance check” function, the efficiency of the working strokes in individual cylinders was assessed and an increase in torque of 5 Nm compared to the base torque in cylinders 1, 5 was established; by 1 Nm in cylinder 3; a decrease of 7 Nm and 4 Nm in cylinders 6 and 2, respectively, indicating a significant deterioration in the efficiency of cylinders 6 and 2. At the same time, in cylinder 6, the deterioration was obviously caused by a malfunction of the fuel system elements, and in cylinder 2, it was a consequence of a decrease in the cyclic supply to ensure uniformity of the stroke, which, in turn, leads to a leaner mixture, a decrease in indicator work and, accordingly, torque.

The analysis of the actual causes of the influence of cylinder operation on the above-studied indicators can be done on the basis of in-depth physical diagnostics of individual nodes or on the basis of reconstruction of the working process in individual cylinders using a mathematical model of the engine.