Engine control method and device

Abstract

The invention provides an engine control method and device. The method comprises the steps as follows: in response to the conditions that an engine is in a low idle state and does not have an electrical fault, the current rail pressure set value and the current rail pressure actual value of a common rail pipe are obtained; rail pressure difference value between the rail pressure set value and therail pressure actual value is calculated; if the rail pressure difference value is larger than the first threshold value, low idle speed set value and the rail pressure set value of the engine are increased. On the basis of the principle of low idle speed closed-loop control, the fuel injection quantity can be increased by increasing the low idle set value, gas can be rapidly discharged with increase of the fuel injection quantity, gas in the common rail pipe is reduced, and thus, the flameout probability of the engine is reduced. After the gas enters the common rail pipe, rail pressure in thecommon rail pipe can be reduced to the lowest rail pressure limit value by increasing the rail pressure set value, so that the gas in the common rail pipe is reduced, and the flameout probability ofthe engine is reduced.

Description

technical field [0001] The invention belongs to the technical field of vehicle control, in particular to an engine control method and device. Background technique [0002] At present, the working principle of the electronically controlled high-pressure common rail system is: the fuel passes through the two-stage coarse filter-fuel delivery pump-fine filter-high-pressure fuel pump-common rail pipe-fuel injector from the fuel tank outlet, and the fuel tank to the high-pressure fuel pump inlet The fuel at the place is low-pressure oil, and the fuel between the high-pressure oil pump and the injector is high-pressure oil. During the process of delivering high-pressure oil to the common rail pipe by the high-pressure oil pump, the current rail pressure setting value of the common rail pipe and the rail pressure The actual pressure value realizes precise control of the oil pressure in the common rail pipe, so that the pressure of the high-pressure oil pipe has nothing to do with t...

AI Technical Summary

Problems solved by technology

[0003] However, the engine will be in a low idle state during the working process. The so-called low idle state means that the engine is maintained at the lowest speed of normal operation, the fuel injection volume is reduced, the gas discharge in the common rail pipe is slowed down, and the rail pressure is low in the low idle state. When the setting value is lowered, it is easier for outside air to enter the common rail pipe, so that the rail pressure in the common rail pipe quickly drops to the lowest rail pressure set value, and as the rail pressure drops rapidly, the fuel injection volume also drops rapidly, further reducing gas discharge, and The more gas in the common rail pipe, the easier it is to cause the engine to stall

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