IMPROVEMENT OF DIAGNOSTICS METHODOLOGY OF DIESEL ENGINE WITH COMMON RAIL FUEL SYSTEM IN FREE ACCELERATION MODE

Abstract

Improving the operating efficiency of modern transportation and technological machines for agricultural purposes is impossible to achieve without timely engine diagnostics. Experimental studies were carried out to improve the methodology of diagnostics of diesel engine YaMZ-53445-22 with Common Rail fuel system by evaluating the complex of diagnostic parameters during free acceleration of the engine from minimum to maximum crankshaft speed. The time of free acceleration of the engine when working on all cylinders is 1.84 sec., with the third cylinder disconnected - 2.54 sec. Disconnection of the third cylinder leads to an increase in the amplitude of acceleration from 140 s-2 to 297 s-2, which indicates an increase in the non-uniformity of cylinder operation. The total cyclic fuel supply and fuel consumption increases when one of the cylinders is disconnected, which indicates that the electronic control unit incorrectly calculates the actual cyclic fuel supply. At switching off one of the cylinders, the indicator torque, calculated programmatically relative to the total cycle fuel supply, increases from 243 to 291 Nm at a crankshaft speed of 2630 min-1, while the effective engine performance using the existing means of measurement can not be determined. The developed methodology of diagnostics YaMZ-53445-22 engine in the free acceleration mode implies the assessment of technical condition of the engine based on the analysis of faults detected by the built-in system of diagnostics, as well as by acceleration time, crankshaft acceleration, total cycle fuel supply, fuel consumption and air boost pressure.