Exhaust gas recirculation control device of engine

Abstract

An exhaust gas recirculation control device of an engine is provided. The device includes: an exhaust turbocharger having a turbine disposed in an exhaust passage and a compressor disposed in an intake passage; a low-pressure EGR passage connecting a part of the exhaust passage downstream of the turbine to a part of the intake passage upstream of the compressor; a low-pressure EGR valve disposed in the low-pressure EGR passage and for changing a cross-sectional area of the low-pressure EGR passage; an exhaust shutter valve disposed downstream of the connected part of the exhaust passage to the low-pressure EGR passage, and for changing a cross-sectional area of the exhaust passage; a valve control device for controlling openings of the low-pressure EGR valve and the exhaust shutter valve; and a gear range detector for detecting a gear range of a transmission of a vehicle in which the engine is installed.

Description

technical field [0001] The invention belongs to the technical field related to the exhaust gas backflow control device of the engine. Background technique [0002] Conventionally, there is known an exhaust gas recirculation control device for an engine (for example, refer to Patent Document 1): the exhaust gas recirculation control device for an engine includes an exhaust turbocharger, a turbine provided in an exhaust passage of the engine, and a device for distributing the exhaust gas. A compressor in the intake passage; a low-pressure EGR passage connecting the exhaust passage on the downstream side of the turbine with the intake passage on the upstream side of the compressor; a low-pressure EGR valve arranged in the low-pressure EGR passage, changing The cross-sectional area of ​​the low-pressure EGR passage; and the exhaust throttle valve are arranged on the downstream side of the exhaust passage from a connecting portion of the low-pressure EGR passage, and the cross-se...

AI Technical Summary

Problems solved by technology

In this case, if the exhaust throttle valve is fully open, the differential pressure between the exhaust passage side and the intake passage side of the low-pressure EGR valve in the low-pressure EGR passage is small, so that the Target return flow, in order to realize the changed target return flow through the low-pressure EGR valve, the opening of the low-pressure EGR valve must be greatly changed, so there is a follow-up response to the change of the opening of the low-pressure EGR valve relative to the target return flow sex change problem

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