Patent ID: 6945236

Claim:
An EGR control apparatus of an engine, said EGR control apparatus comprising: a first port to which an intake passage is connected, the first port opening into a combustion chamber of the engine; a second port to which an EGR passage branching out from an exhaust passage is connected, the second port opening into the combustion chamber of the engine; an electrically-operated pressure controller disposed in the EGR passage for regulating pressure at which EGR gas is introduced into the combustion chamber; an EGR control valve disposed in the EGR passage at a point downstream of the pressure controller for controlling the amount of EGR gas introduced into the combustion chamber; wherein the EGR passage branches out from the exhaust passage at a point downstream of an emission control device disposed in the exhaust passage; a supercharger, in which a turbine disposed in the exhaust passage upstream of a point where the EGR passage branches out from the exhaust passage drives a compressor disposed in the intake passage; an auxiliary intake passage connecting the intake passage to the EGR passage at a point upstream of the pressure controller to enable introduction of the intake air into the EGR passage; a first fluid channel regulator for switching a fluid passage between a passage allowing fluid to flow through the auxiliary intake passage and a passage allowing fluid to flow through a portion of the EGR passage upstream of joint between the EGR passage and the auxiliary intake passage into the pressure controller; an interconnect passage branching out from the EGR passage at a point between the pressure controller and the EGR control valve and connecting to the intake passage at a point upstream of the compressor of the supercharger; a second fluid channel regulator for switching a fluid passage between a passage allowing the fluid to flow through the interconnect passage and a passage allowing the fluid to flow through a portion of the intake passage upstream of a joint between the intake passage and the interconnect passage into the compressor of the supercharger; an operating condition sensing device for detecting operating conditions of the engine; and a control unit for controlling the first fluid channel regulator and the second fluid channel regulator according to the operating conditions of the engine detected by the operating condition sensing device.