JP7129187B2 - Exhaust gas purification device - Google Patents

Description

The present invention relates to an exhaust gas purifier.

DPFs (Diesel Particulate Filters) and GPFs (Gasoline Particulate Filters) are known as filters for vehicles that capture and remove particulate matter such as soot contained in exhaust gas discharged from an engine. Such filters become clogged with particulate matter with continued use. Therefore, a regeneration process is performed in which the temperature of the filter is raised to burn the captured soot and remove it from the filter.

If there is relatively little oxygen in the exhaust gas during the regeneration process, the combustion of soot will not be promoted. Therefore, a technique has been developed in which oxygen is supplemented by injecting air into the exhaust pipe (for example, Patent Document 1).

Japanese Patent Application Laid-Open No. 2003-314245

Soot combustion in the filter begins upstream of the filter where oxygen is supplied and progresses downstream of the filter. In addition, heat generated by combustion of soot also propagates from the upstream side to the downstream side of the filter. Therefore, on the downstream side of the filter, the combustion heat of soot generated on the downstream side of the filter and the heat propagated from the upstream side of the filter are combined, and the temperature tends to be high. In this way, burning the soot deposited on the filter may cause the filter to reach a high temperature locally, which may have a thermal effect on the body of the vehicle on which the filter is mounted.

SUMMARY OF THE INVENTION An object of the present invention is to provide an exhaust gas purifier capable of suppressing the influence of heat on a vehicle body.

In order to solve the above problems, the exhaust gas purifier of the present invention includes an upstream exhaust pipe through which exhaust gas discharged from an engine passes, a tubular body connected to the downstream side of the upstream exhaust pipe, and a downstream of the tubular body. At least oxygen is supplied through a downstream exhaust pipe connected to the side, a filter provided in the tubular body, and a supply port formed on the upstream side of the filter in the tubular body and on the vehicle body side of the communication point with the upstream exhaust pipe. and an oxygen - containing gas supply unit that supplies an oxygen-containing gas containing further away from the vehicle body .

In order to solve the above problems, another exhaust gas purification device of the present invention includes an upstream exhaust pipe through which exhaust gas discharged from an engine passes, a pipe body connected to the downstream side of the upstream exhaust pipe, and a pipe body an oxygen-containing gas supply unit for supplying an oxygen-containing gas containing at least oxygen through a downstream exhaust pipe connected to the downstream side of the pipe, a filter provided in the tubular body, and a supply port formed in the upstream exhaust pipe; A control unit that injects fuel into the intake port connected to the engine before warming up, and injects fuel into the combustion chamber of the engine after warming up the engine, and between the upstream exhaust pipe and the pipe body The communication point is positioned closer to the vehicle body than the center of the cross section of the flow path of the filter , and the communication point between the tubular body and the downstream exhaust pipe is separated from the center of the flow path cross section of the filter from the vehicle body .

ADVANTAGE OF THE INVENTION According to this invention, it becomes possible to suppress the influence of the heat to a vehicle body.

1 is a schematic diagram showing the configuration of an engine system; FIG. It is a schematic diagram showing the configuration of an exhaust gas purification device. FIG. 4 is a diagram for explaining the temperature of the GPF when regeneration processing is performed; It is a schematic diagram showing the configuration of an exhaust gas purifier of a first modification. It is a schematic diagram showing the configuration of an exhaust gas purifier of a second modification. FIG. 11 is a schematic diagram showing the configuration of an exhaust gas purifying device of a third modified example;

Preferred embodiments of the present invention will be described in detail below with reference to the accompanying drawings. The dimensions, materials, and other specific numerical values shown in these embodiments are merely examples for facilitating understanding of the invention, and do not limit the invention unless otherwise specified. In the present specification and drawings, elements having substantially the same function and configuration are given the same reference numerals to omit redundant description, and elements that are not directly related to the present invention are omitted from the drawings. do.

FIG. 1 is a schematic diagram showing the configuration of an engine system 100. As shown in FIG. In FIG. 1, the flow of signals is indicated by dashed arrows. As shown in FIG. 1, an engine system 100 is provided with an ECU (Engine Control Unit) 110 which is a microcomputer including a central processing unit (CPU), a ROM storing programs and the like, and a RAM as a work area. , the ECU 110 controls the entire engine 120 . However, in the following, configurations and processes related to this embodiment will be described in detail, and descriptions of configurations and processes unrelated to this embodiment will be omitted. Also, here, as the engine 120, a gasoline engine will be described as an example.

The engine 120 is a multi-cylinder engine having a plurality of cylinders 122a, and an intake manifold 126 communicates with an intake port 124 of each cylinder 122a formed in a cylinder block 122. As shown in FIG. An intake pipe 130 communicates with the collective portion of the intake manifold 126 via an air chamber 128 . An air cleaner 132 is provided upstream of the intake pipe 130 . A throttle valve 134 is provided downstream of the air cleaner 132 in the intake pipe 130 .

An exhaust manifold 138 communicates with an exhaust port 136 of each cylinder 122 a formed in the cylinder block 122 of the engine 120 . A muffler 142 communicates with the collective portion of the exhaust manifold 138 via an exhaust pipe 140 . The exhaust pipe 140 is provided with an exhaust gas purification device 200 which will be described later. Hereinafter, the exhaust pipe 140 that communicates between the collective portion of the exhaust manifold 138 and the filter unit 220 (described later) that constitutes the exhaust gas purification device 200 is referred to as an upstream exhaust pipe 140a, and the exhaust pipe that communicates between the filter unit 220 and the muffler 142 is referred to as an upstream exhaust pipe 140a. Pipe 140 may be referred to as downstream exhaust pipe 140b. Note that the upstream exhaust pipe 140a and the downstream exhaust pipe 140b have substantially the same inner diameter.

The engine 120 is provided with a spark plug 148 for each cylinder 122a such that the tip thereof is positioned within the combustion chamber 146. As shown in FIG. An injector 150 is provided in the combustion chamber 146 of each cylinder 122a.

The engine system 100 includes an intake air amount sensor 160 for detecting the amount of intake air flowing into the engine 120, and an intake air amount sensor 160 for detecting the amount of intake air flowing into the engine 120. An intake air temperature sensor 162 is provided to detect the temperature. The engine system 100 is also provided with a throttle opening sensor 164 that detects the opening of the throttle valve 134 . The engine system 100 is also provided with a crank angle sensor 166 that detects the crank angle of the crankshaft and an accelerator opening sensor 168 that detects the opening of an accelerator (not shown).

Each of these sensors 160 to 168 is connected to ECU 110 and outputs a signal indicating a detected value to ECU 110 .

ECU 110 acquires signals output from sensors 160 to 168 and controls engine 120 . When the ECU 110 controls the engine 120, the ECU 110 controls the signal acquisition section 180, the target value derivation section 182, the air amount determination section 184, the injection amount determination section 186, the throttle opening determination section 188, the ignition timing determination section 190, the drive control section 192, and the like. function as

The signal acquisition unit 180 acquires signals indicating values detected by the sensors 160-168. A target value derivation unit 182 derives the current engine speed based on the signal indicating the crank angle acquired from the crank angle sensor 166 . In addition, the target value derivation unit 182 refers to a map stored in advance based on the derived engine speed and the signal indicating the accelerator opening acquired from the accelerator opening sensor 168, and calculates the target torque and the target engine speed. to derive

The air amount determining section 184 determines the target air amount to be supplied to each cylinder 122a based on the target engine speed and the target torque derived by the target value deriving section 182 . The throttle opening determination unit 188 derives the total amount of the target air amounts of the cylinders 122a determined by the air amount determination unit 184, and determines the target throttle opening for taking in the total amount of air from the outside.

The injection amount determination unit 186 supplies fuel to each cylinder 122a based on the target engine speed and target torque derived by the target value derivation unit 182, the target air amount for each cylinder 122a determined by the air amount determination unit 184, and the like. Determine the target injection amount of fuel to be used. In addition, injection amount determination unit 186 is based on a signal indicating the crank angle detected by crank angle sensor 166 in order to inject the determined target injection amount of fuel from injector 150 during the intake stroke or compression stroke of engine 120. , determine the target injection timing and target injection period for each injector 150 .

The ignition timing determining unit 190 adjusts the spark plug 148 in each cylinder 122a based on the target engine speed and target torque derived by the target value deriving unit 182, a signal indicating the crank angle detected by the crank angle sensor 166, and the like. determines the target ignition timing of

The drive control unit 192 drives a throttle valve actuator (not shown) so that the throttle valve 134 opens at the target throttle opening determined by the throttle opening determination unit 188 . Further, the drive control unit 192 drives the injector 150 with the target injection timing and the target injection period determined by the injection amount determination unit 186 to cause the injector 150 to inject the target injection amount of fuel. Further, the drive control section 192 ignites the spark plug 148 at the target ignition timing determined by the ignition timing determination section 190 .

Exhaust gas generated by the combustion of fuel in the combustion chamber 146 is discharged to the outside through the exhaust pipe 140 in this way. Exhaust gas contains hydrocarbons (HC: Hydro Carbon), carbon monoxide (CO), nitrogen oxides (NOx), and particulate matter such as soot, which must be removed. Therefore, the exhaust gas purification device 200 is provided in the exhaust pipe 140, and the hydrocarbons, carbon monoxide, nitrogen oxides, and particulate matter are removed in the exhaust gas purification device 200. FIG.

It should be noted that the ECU 110 functions as a deposit amount estimation unit 194 and a supply control unit 196 when functioning as an exhaust gas purifier. The deposit amount estimation unit 194 and the supply control unit 196 will be described in detail later.

(Exhaust gas purification device 200)
FIG. 2 is a schematic diagram showing the configuration of the exhaust gas purification device 200. As shown in FIG. In FIG. 2 , the flow of signals is indicated by dashed arrows, and the body of the vehicle on which engine 120 is mounted is indicated by one-dot chain lines. As shown in FIG. 2 , the exhaust gas purifier 200 includes a deposit amount estimation unit 194, a supply control unit 196, a three-way catalyst 210, a filter unit 220, and an oxygen-containing gas supply unit 230. including. In this embodiment, the exhaust gas purification device 200 is provided below the vehicle body.

The three-way catalyst 210 is provided inside the upstream exhaust pipe 140a. The three-way catalyst 210 includes catalytic components such as platinum (Pt), palladium (Pd), rhodium (Rh), and the like. Three-way catalyst 210 removes hydrocarbons, carbon monoxide, and nitrogen oxides in the exhaust gas discharged from exhaust port 136 .

Filter unit 220 includes a tubular body 222 and a GPF (filter) 224 . The tubular body 222 connects the upstream exhaust pipe 140a and the downstream exhaust pipe 140b. Specifically, the tubular body 222 includes an enlarged diameter portion 222a, a same diameter portion 222b, and a reduced diameter portion 222c.

The enlarged diameter portion 222a has an upstream end (one end) connected to the upstream exhaust pipe 140a and a downstream end (the other end) connected to the same diameter portion 222b. The enlarged diameter portion 222a gradually increases in diameter (inner diameter and outer diameter) from the upstream side to the downstream side. That is, the inner diameter of one end of the enlarged diameter portion 222a is substantially equal to the inner diameter of the upstream exhaust pipe 140a. Further, in the present embodiment, the upstream exhaust pipe 140a and the enlarged diameter portion 222a are connected so that their communicating portion 222aa is positioned at the center of the cross section of the flow path of the enlarged diameter portion 222a.

The same diameter portion 222b has an upstream end connected to the enlarged diameter portion 222a and a downstream end connected to the reduced diameter portion 222c. The diameter (inner diameter and outer diameter) of the same diameter portion 222b is substantially constant. The diameter of the same diameter portion 222b is substantially equal to the inner diameter of the other end of the enlarged diameter portion 222a and the inner diameter of one end of the reduced diameter portion 222c.

The reduced diameter portion 222c has an upstream end (one end) connected to the same diameter portion 222b, and a downstream end (the other end) connected to the downstream exhaust pipe 140b. The diameter-reduced portion 222c gradually decreases in diameter (inner diameter and outer diameter) from the upstream side to the downstream side. That is, the inner diameter of the other end of the reduced diameter portion 222c is substantially equal to the inner diameter of the downstream exhaust pipe 140b. Further, in the present embodiment, the diameter-reduced portion 222c and the downstream exhaust pipe 140b are connected such that the communicating portion 222ca is positioned at the center of the cross-section of the diameter-reduced portion 222c. That is, the upstream exhaust pipe 140a, the tubular body 222, and the downstream exhaust pipe 140b are coaxial.

The GPF 224 is provided within the same diameter portion 222b. That is, GPF 224 is provided downstream of three-way catalyst 210 in exhaust pipe 140 . Also, the GPF 224 is coaxial with the three-way catalyst 210 (upstream exhaust pipe 140a). GPF 224 traps particulate matter (soot) in the exhaust gas exhausted from exhaust port 136 . GPF 224 is a wall-flow filter. In this embodiment, the GPF 224 has a function of trapping particulate matter and a catalyst that purifies exhaust gas (for example, a three-way catalyst similar to the three-way catalyst 210 that removes hydrocarbons, carbon monoxide, and nitrogen oxides). catalyst).

Exhaust gas purifier 200 is configured to have GPF 224 in exhaust pipe 140, so that particulate matter can be deposited on GPF 224 and removed from the exhaust gas. Then, the particulate matter (carbon C) deposited on the GPF 224 is removed from the GPF 224 by advancing the reaction (oxidation reaction of particulate matter) shown in the following formula (1), and the GPF 224 is regenerated.
C + O ₂ → CO ₂ Formula (1)

However, since the engine 120 of the present embodiment is a gasoline engine, the injection amount determination unit 186 basically determines the target injection amount of fuel so as to achieve the stoichiometric air-fuel ratio (stoichiometric). During operation at the stoichiometric air-fuel ratio, the concentration of oxygen contained in the exhaust gas is low, so regeneration of the GPF 224 is not promoted.

Therefore, the exhaust gas purifier 200 includes the oxygen-containing gas supply unit 230, and when the amount of particulate matter deposited in the GPF 224 exceeds a predetermined deposition threshold value, the oxygen-containing gas supply unit 230 is driven to supply the GPF 224. Increase the oxygen concentration supplied.

Specifically, the oxygen-containing gas supply unit 230 includes a supply pipe 232 and a pump 234 . The supply pipe 232 is connected to the enlarged diameter portion 222a, and the end thereof is open to the atmosphere. A pump 234 is provided in the supply pipe 232 and supplies outside air (oxygen-containing gas) to the supply pipe 232 .

The deposition amount estimation unit 194 estimates the deposition amount of particulate matter in the GPF 224 . The deposition amount estimator 194 estimates the deposition amount of particulate matter based on, for example, the operating conditions of the engine 120 and the operating time (travel distance) from the last supply of outside air to the present.

The supply control unit 196 controls the oxygen-containing gas supply unit 230 to start supplying outside air when the engine operating state such as the temperature of the exhaust gas satisfies the regeneration processing condition when the deposition amount is equal to or greater than the deposition threshold. .

FIG. 3 is a diagram illustrating the temperature of the GPF 224 when regeneration processing is performed in the exhaust gas purifier 200 of this embodiment. The exhaust gas purifier 200 of this embodiment suppresses the influence of heat on the vehicle body by devising the position of the supply port 250 of the outside air. Specifically, as shown in FIG. 3, in the exhaust gas purifying device 200, the outside air supply port 250 is formed closer to the vehicle body than the center of the enlarged diameter portion 222a. In other words, the supply port 250 is formed closer to the vehicle body than the axis of the tubular body 222 (the axis of the upstream exhaust pipe 140a) in the enlarged diameter portion 222a. The supply pipe 232 is connected to the supply port 250 .

In the exhaust gas purifying device 200 , when the pump 234 is driven to supply outside air to perform regeneration processing, the outside air reaches the GPF 224 through the supply port 250 . Here, as described above, the supply port 250 is positioned on the vehicle body side of the enlarged diameter portion 222a. Therefore, outside air first reaches the upstream side and the vehicle body side of the GPF 224 . Then, the particulate matter accumulated in the GPF 224 first begins to burn from the upstream side and the vehicle body side (indicated by B1 in FIG. 3), and then spreads in the direction away from the vehicle body. Thus, in the exhaust gas purifying device 200, as shown in B1->B2->B3->B4->B5 in FIG. Matter burns.

Then, in the exhaust gas purification device 200, the combustion heat propagates from the upstream side of the GPF 224 toward the downstream side and in a direction away from the vehicle body. Therefore, in the exhaust gas purifying device 200, the downstream side of the GPF 224 and the farthest point from the vehicle body (indicated by B5 in FIG. 3) is where the heat propagated from the upstream side and the vehicle body side and the combustion heat of the particulate matter are mixed. Together, they reach the highest temperature.

As described above, according to the exhaust gas purifying device 200 of the present embodiment, by devising the position of the supply port 250 of the outside air, the portion that reaches the highest temperature when the regeneration process is performed is positioned away from the vehicle body. can be As a result, it is possible to suppress the propagation of heat generated in the regeneration process to the vehicle body. Therefore, the influence of heat on the vehicle body can be suppressed.

(Modification)
FIG. 4 is a schematic diagram showing the configuration of an exhaust gas purifier 300 of a first modified example. FIG. 5 is a diagram illustrating an exhaust gas purifier 400 of a second modification. FIG. 6 is a diagram illustrating an exhaust gas purifier 500 of a third modification. Components that are substantially the same as those of the exhaust gas purifier 200 are denoted by the same reference numerals, and descriptions thereof are omitted. Also, in FIGS. 4 and 5, the accumulation amount estimation unit 194 and the supply control unit 196 are omitted for easy understanding.

(Exhaust gas purification device 300)
As shown in FIG. 4, the exhaust gas purification device 300 is provided below the vehicle body. Exhaust gas purifier 300 includes a deposit amount estimator 194 , a supply controller 196 , a three-way catalyst 210 , a filter unit 220 and an oxygen-containing gas supplier 230 .

The exhaust gas purifying device 300 differs from the exhaust gas purifying device 200 only in the positions of a communicating portion 322aa between the upstream exhaust pipe 140a and the enlarged diameter portion 222a and a communicating portion 322ca between the reduced diameter portion 222c and the downstream exhaust pipe 140b.

Specifically, in the exhaust gas purifying device 300, the upstream exhaust pipe 140a and the enlarged diameter portion 222a are arranged such that the communicating portion 322aa thereof extends from the center of the flow passage cross section of the enlarged diameter portion 222a (the flow passage cross section of the GPF 224) to the vehicle body. connected so as to be spaced apart from Similarly, in the exhaust gas purifying device 300, the diameter-reduced portion 222c and the downstream exhaust pipe 140b are separated from the vehicle body from the center of the flow path cross section of the diameter-reduced portion 222c (the flow path cross section of the GPF 224). position. In other words, the upstream exhaust pipe 140a, the tubular body 222, and the downstream exhaust pipe 140b are connected such that the communication points 322aa and 322ca are relatively unevenly distributed vertically downward.

With the above configuration, the exhaust gas actively flows on the lower side of the GPF 224, that is, the side away from the vehicle body. In other words, the amount of exhaust gas passing through is greater on the side (lower side) of the GPF 224 spaced from the vehicle body than on the side of the vehicle body (upper side). As a result, the amount of particulate matter deposited is greater on the side (lower side) of the GPF 224 spaced from the vehicle body than on the side of the vehicle body (upper side).

For this reason, when the regeneration process is executed, the side of the GPF 224 that is separated from the vehicle body, which has a relatively large amount of particulate matter, generates greater combustion heat than the vehicle body side.

On the other hand, in the exhaust gas purifier 300 , when the pump 234 is driven to supply the outside air in order to perform the regeneration process, the outside air reaches the GPF 224 through the supply port 250 . Here, as described above, the supply port 250 is positioned on the vehicle body side of the enlarged diameter portion 222a. Therefore, outside air first reaches the upstream side and the vehicle body side of the GPF 224 . Then, the particulate matter accumulated in the GPF 224 first begins to burn from the upstream side and the vehicle body side, and then spreads in the direction away from the vehicle body. That is, in the exhaust gas purification device 300, similarly to the exhaust gas purification device 200, the particulate matter is burned from the upstream side to the downstream side of the GPF 224 and in the direction away from the vehicle body. Then, in the exhaust gas purifying device 300, the combustion heat propagates from the upstream side of the GPF 224 toward the downstream side and in a direction away from the vehicle body.

Therefore, when the regeneration process is executed, the heat propagated from the upstream side and the vehicle body side of the GPF 224 and the relatively large amount of combustion heat of particulate matter are combined, and the temperature is higher than the vehicle body side. get higher That is, the vehicle body side of the GPF 224 has a lower temperature than the vehicle body side because heat is propagated in a direction away from the vehicle body and the amount of particulate matter deposited is relatively small. As a result, it is possible to suppress the propagation of heat generated in the regeneration process to the vehicle body.

(Exhaust gas purification device 400)
The exhaust gas purification device 400 is provided below the vehicle body. Exhaust gas purifier 400 includes a deposit amount estimator 194 , a supply controller 196 , a three-way catalyst 210 , a filter unit 220 and an oxygen-containing gas supplier 230 .

As shown in FIG. 5, the exhaust gas purifying device 400 differs from the exhaust gas purifying device 300 only in the communicating portion 422aa between the upstream exhaust pipe 140a and the enlarged diameter portion 222a and the position of the supply port 450. As shown in FIG.

Specifically, in the exhaust gas purifying device 400, the upstream exhaust pipe 140a and the enlarged diameter portion 222a are arranged so that the communicating portion 422aa thereof extends from the center of the flow passage cross section of the enlarged diameter portion 222a (the flow passage cross section of the GPF 224) to the vehicle body. connected so as to be located on the side. In other words, the upstream exhaust pipe 140a and the tubular body 222 are connected so that the communicating portion 422aa is relatively unevenly distributed vertically upward (toward the vehicle body). On the other hand, in the exhaust gas purifying device 400, similarly to the exhaust gas purifying device 300, the diameter-reduced portion 222c and the downstream exhaust pipe 140b have a communication portion 322ca that is equal to the passage cross section of the diameter-reduced portion 222c (the passage of the GPF 224). cross section) so that they are separated from the vehicle body from the center.

Supply port 450 is formed between three-way catalyst 210 and enlarged diameter portion 222a in upstream exhaust pipe 140a. The supply pipe 232 of the oxygen-containing gas supply unit 230 is connected to the supply port 450 .

Then, when the pump 234 is driven and the outside air is supplied to perform the regeneration process, the outside air reaches the GPF 224 through the supply port 450 and the communicating portion 422aa. Here, as described above, the communicating portion 422aa is located on the vehicle body side of the enlarged diameter portion 222a. Therefore, the particulate matter accumulated in the GPF 224 burns from the upstream side to the downstream side of the GPF 224 and in the direction away from the vehicle body, similarly to the exhaust gas purification device 200 .

Then, in the exhaust gas purification device 400, the combustion heat propagates from the upstream side of the GPF 224 toward the downstream side and in a direction away from the vehicle body. Therefore, in the exhaust gas purifying device 400, the temperature is the highest at the location downstream of the GPF 224 and furthest from the vehicle body.

Therefore, in the exhaust gas purifying device 400, the portion that reaches the highest temperature when the regeneration process is performed can be located away from the vehicle body. As a result, it is possible to suppress the propagation of heat generated in the regeneration process to the vehicle body.

In addition, the exhaust gas purification device 400 can efficiently suppress the influence of heat on the vehicle body in an engine whose operation is controlled so that particulate matter accumulates substantially uniformly (without bias) in the GPF 224. can. For example, in addition to the combustion chamber 146, an injector 150 is also provided in the intake port 124, and fuel is injected from the injector 150 provided in the intake port 124 (port injection) in cold weather or when the engine is started. , the amount of particulate matter generated can be relatively small. In addition, by injecting fuel from the injector 150 provided in the combustion chamber 146 after the engine is warmed up (direct injection), the amount of particulate matter generated can be relatively reduced. By relatively reducing the amount of particulate matter generated in this manner, particulate matter can be deposited substantially uniformly on the GPF 224 . However, when the particulate matter cannot be deposited substantially uniformly in the GPF 224, the exhaust gas purification device 200 can more efficiently suppress the influence of heat on the vehicle body.

(Exhaust gas purification device 500)
The exhaust gas purification device 500 is provided below the vehicle body. Exhaust gas purification device 500 includes a three-way catalyst 210 and a filter unit 220 . As shown in FIG. 6, the exhaust gas purifying device 500 differs from the exhaust gas purifying device 300 only in that it does not have the deposition amount estimation unit 194, the supply control unit 196, and the oxygen-containing gas supply unit 230. FIG.

Also in the exhaust gas purifier 500, the upstream exhaust pipe 140a, the tubular body 222, and the downstream exhaust pipe 140b are connected such that the communication points 322aa and 322ca are relatively unevenly distributed vertically downward.

With the above configuration, the amount of particulate matter deposited is greater on the side (lower side) of the GPF 224 spaced from the vehicle body than on the side of the vehicle body (upper side). For this reason, when the regeneration process is executed, the temperature of the side of the GPF 224 away from the vehicle body, where the particulate matter is relatively large, becomes higher than the temperature of the vehicle body side. That is, the temperature on the vehicle body side of the GPF 224 can be made lower than the temperature on the side away from the vehicle body. As a result, it is possible to suppress the propagation of heat generated in the regeneration process to the vehicle body.

Since the exhaust gas purifier 500 does not include the oxygen-containing gas supply unit 230, the fuel is cut (the accelerator opening detected by the accelerator opening sensor 168 is 0 (zero) and the vehicle speed is not 0). The playback process is automatically executed at the time of

Although the preferred embodiments of the present invention have been described above with reference to the accompanying drawings, it goes without saying that the present invention is not limited to such embodiments. It is obvious that a person skilled in the art can conceive of various modifications or modifications within the scope of the claims, and it should be understood that these also belong to the technical scope of the present invention. be done.

In addition, in the above-described embodiment and modified example, the configuration in which the ECU 110 functions as the accumulation amount estimation unit 194 and the supply control unit 196 has been described as an example. However, the accumulation amount estimation unit 194 and the supply control unit 196 may be configured separately from the ECU 110 .

Further, in the above-described embodiment and modifications, the case where the oxygen-containing gas supply unit 230 supplies outside air as the oxygen-containing gas has been described as an example. However, the oxygen-containing gas supplied by the oxygen-containing gas supply unit 230 may be any gas having a higher oxygen concentration than the exhaust gas with the stoichiometric air-fuel ratio.

Further, in the above-described embodiment and modified example, the configuration in which the GPF 224 contains a catalyst has been described as an example, but the GPF 224 only needs to be able to capture particulate matter, and does not need to contain a catalyst.

Further, in the exhaust gas purifying device 400 of the modified example, the diameter-reduced portion 222c and the downstream exhaust pipe 140b are arranged such that the communicating portion 322ca thereof is positioned away from the vehicle body from the center of the flow passage cross-section of the diameter-reduced portion 222c. The case where it is connected to is explained as an example. However, the point of communication between the diameter-reduced portion 222c and the downstream exhaust pipe 140b may be the center of the flow passage cross-section of the diameter-reduced portion 222c, or may be on the vehicle body side of the center.

Further, in the above embodiment, a gasoline engine was described as an example of the engine 120 . However, the exhaust gas purification device 200 can remove particulate matter contained in the exhaust gas discharged from the engine regardless of the type of engine (for example, diesel engine).

INDUSTRIAL APPLICABILITY The present invention can be used for exhaust gas purifiers.

140a upstream exhaust pipe 140b downstream exhaust pipe 200, 300, 400, 500 exhaust gas purification device 222 tubular body 224 GPF (filter)
230 oxygen-containing gas supply unit 250, 450 supply port

Claims (2)

an upstream exhaust pipe through which exhaust gas discharged from the engine passes;
a tubular body connected to the downstream side of the upstream exhaust pipe;
a downstream exhaust pipe connected to the downstream side of the tubular body;
a filter provided within the tubular body;
an oxygen-containing gas supply unit that supplies an oxygen-containing gas containing at least oxygen through a supply port formed upstream of the filter in the tubular body and closer to the vehicle body than a communicating portion with the upstream exhaust pipe;
with
An exhaust gas purifying device, wherein a communicating portion between the upstream exhaust pipe and the tubular body and a communicating portion between the tubular body and the downstream exhaust pipe are separated from the vehicle body from the center of the flow path cross section of the filter. an upstream exhaust pipe through which exhaust gas discharged from the engine passes;
a tubular body connected to the downstream side of the upstream exhaust pipe;
a downstream exhaust pipe connected to the downstream side of the tubular body;
a filter provided within the tubular body;
an oxygen-containing gas supply unit that supplies an oxygen-containing gas containing at least oxygen through a supply port formed in the upstream exhaust pipe;
a control unit that injects fuel into an intake port connected to the engine before warming up the engine, and injects fuel into a combustion chamber of the engine after warming up the engine;
with
a communicating portion between the upstream exhaust pipe and the tubular body is positioned closer to the vehicle body than the center of the flow passage cross section of the filter ,
An exhaust gas purifying device , wherein a communicating portion between the tubular body and the downstream exhaust pipe is separated from the vehicle body from the center of the flow passage cross section of the filter .

Images