초록 ▼

In an exhaust gas control apparatus for an internal combustion engine, in a case where an internal combustion engine is in a high load operating state while a PM trapping ability forcible recovery process for a particulate filter is being performed, EGR gas is caused to flow back from a portion down

In an exhaust gas control apparatus for an internal combustion engine, in a case where an internal combustion engine is in a high load operating state while a PM trapping ability forcible recovery process for a particulate filter is being performed, EGR gas is caused to flow back from a portion downstream of the particulate filter in an exhaust passage to a portion upstream of a compressor housing in an intake passage, whereby the EGR gas is cooled by an intercooler. In a case where the internal combustion engine is in a low load operating state while the PM trapping ability forcible recovery process is being performed, the EGR gas is caused to flow back from the portion downstream of the particulate filter in the exhaust passage to a portion downstream of the intercooler in the intake passage, whereby the EGR gas is prevented from being unnecessarily cooled.

대표청구항 ▼

The invention claimed is: 1. An exhaust gas control apparatus for an internal combustion engine, comprising: a particulate filter that is provided in an exhaust passage of the internal combustion engine; a supercharger that is provided in an intake passage of the internal combustion engine; an inte

The invention claimed is: 1. An exhaust gas control apparatus for an internal combustion engine, comprising: a particulate filter that is provided in an exhaust passage of the internal combustion engine; a supercharger that is provided in an intake passage of the internal combustion engine; an intercooler that is provided in a portion downstream of the supercharger in the intake passage; a filter recovery device that recovers a trapping ability of the particulate filter by increasing a temperature of the particulate filter; a load obtaining device that obtains a load of the internal combustion engine; and an Exhaust Gas Recirculation (EGR) control device that controls exhaust gas to flow back from a portion downstream of the particulate filter in the exhaust passage to a portion downstream of the intercooler in the intake passage without passing through the intercooler in a case where a load of the internal combustion engine is equal to or lower than a predetermined load, and for controlling the exhaust gas to flow back from the portion downstream of the particulate filter in the exhaust passage to a portion upstream of the supercharger in the intake passage in a case where the load of the internal combustion engine is higher than the predetermined load, while the trapping ability of the particulate filter is being recovered. 2. The exhaust gas control apparatus for an internal combustion engine, according to claim 1, further comprising: a first EGR gas take out pipe that is connected to the exhaust passage at the portion downstream of the particulate filter; a second EGR gas take out pipe that is connected to the exhaust passage at a portion upstream of the particulate filter; a first EGR gas supply pipe that is connected to the intake passage at the portion upstream of the supercharger; a second EGR gas supply pipe that is connected to the intake passage at the portion downstream of the intercooler; a common EGR gas pipe whose one end is divided into two portions one of which is connected to the first EGR gas take out pipe and the other of which is connected to the second EGR gas take out pipe, and whose other end is divided into two portions one of which is connected to the first EGR gas supply pipe and the other of which is connected to the second EGR gas supply pipe; a first three-way valve that is provided at the one end of the common EGR gas pipe; and a second three-way valve that is provided at the other end of the common EGR gas pipe, wherein while the trapping ability of the particulate filter is being recovered, in the case where the load of the internal combustion engine is equal to or lower than the predetermined load, the EGR control device controls the first three-way valve so as to provide communication between the first EGR gas take out pipe and the common EGR gas pipe, and controls the second three-way valve so as to provide communication between the second EGR gas supply pipe and the common EGR gas pipe, and in the case where the load of the internal combustion engine is higher than the predetermined load, the EGR control device controls the first three-way valve so as to provide communication between the first EGR gas take out pipe and the common EGR gas pipe, and controls the second three-way valve so as to provide communication between the first EGR gas supply pipe and the common EGR gas pipe. 3. The exhaust gas control apparatus for an internal combustion engine, according to claim 2, wherein the common EGR gas pipe is provided with an EGR cooler, a bypass passage that bypasses the EGR cooler, and a passage switching valve that stops one of a flow of the exhaust gas through the EGR cooler and a flow of the exhaust gas through the bypass passage; and while the trapping ability of the particulate filter is being recovered, in the case where the load of the internal combustion engine is equal to or lower than the predetermined load, the EGR control device controls the passage switching valve so as to stop the flow of the exhaust gas through the EGR cooler, and in the case where the load of the internal combustion engine is higher than the predetermined load, the EGR control device controls the passage switching valve so as to stop the flow of the exhaust gas through the bypass passage. 4. The exhaust gas control apparatus for an internal combustion engine, according to claim 1, wherein the load obtaining device obtains the load of the internal combustion engine based on an accelerator pedal operation amount of a vehicle. 5. The exhaust gas control apparatus for an internal combustion engine, according to claim 4, wherein the load obtaining device determines that the load of the internal combustion engine is high when the accelerator pedal operation amount is larger than a predetermined amount, and determines that the load of the internal combustion engine is low when the accelerator pedal operation amount is equal to or smaller than the predetermined amount. 6. The exhaust gas control apparatus for an internal combustion engine, according to claim 1, wherein while the trapping ability of the particulate filter is not being recovered, the EGR control device controls the exhaust gas to flow back from a portion upstream of the particulate filter in the exhaust passage to the portion downstream of the intercooler in the intake passage.