Diagnosis method for drift failure of rail pressure sensor in common rail system

Abstract

The invention discloses a diagnosis method for a drift failure of a rail pressure sensor in a common rail system. The diagnosis method is completed before starting and after stopping a high-voltage common rail engine and the drift failure of the rail pressure sensor can be detected by comparing a rail pressure value with an atmospheric pressure value on the premise that the drift failure detection condition is satisfied. The diagnosis method can satisfy the on-board diagnosis (OBD) requirement proposed in emission regulations of national standard 4 or above, and a reference scheme can be provided for the OBD technology of domestic diesel engine. A good effect can be reached in the application of real engineering.

Description

technical field [0001] The invention belongs to the technical field of electric control of internal combustion engines, and relates to a method for diagnosing a fault of fuel injection pressure in an electronically controlled high-pressure common rail system, in particular to a method for diagnosing a drift fault of a rail pressure sensor in a common rail system. Background technique [0002] In order to adapt to the increasingly stringent emission regulations, the diesel engine high-pressure common rail system has been widely used, and is recognized by the entire internal combustion engine industry as one of the three major breakthroughs in the 20th century. The high-pressure common rail fuel injection system can not only achieve higher injection pressure, but also independently and flexibly control the fuel injection timing, fuel injection rate and fuel injection pressure to achieve the ideal fuel injection law, while reducing emissions and ensuring excellent fuel efficienc...

AI Technical Summary

Problems solved by technology

This method has natural defects. On the one hand, when the rail pressure sensor drifts and fails, it may not necessarily cause startup difficulties. Only when the actual rail pressure value is much smaller than the sensor measurement value will there be startup difficulties; on the other hand, the diagnostic The fault is not comprehensive. When the rail pressure sensor drifts negatively (that is, the actual rail pressure value is much greater than the sensor measurement value), this method cannot detect it; moreover, another control device needs to be triggered when the internal combustion engine is difficult to start To judge the fault, increase the software overhead and cost

Images