JP2019167902A - Exhaust emission control device - Google Patents

Abstract

To efficiently burn soot.
An exhaust gas purification apparatus 200 includes a filter (GPF 224). The filter includes an outer cylinder 312 and a filter wall provided in the outer cylinder 312. An upstream exhaust pipe 140a and a downstream exhaust pipe 140b are provided. Is located in the upstream space U in the outer cylinder 312 so that the axial direction of the outer cylinder 312 and the axial direction of the outer cylinder 312 intersect with each other. A portion within a predetermined range from the communication portion 222 a is not in contact with the tubular body 222.
[Selection] Figure 2

Description

  The present invention relates to an exhaust gas purification device.

  DPF (Diesel Particulate Filter) and GPF (Gasoline Particulate Filter) are known as filters for vehicles that capture and remove particulate matter such as soot contained in exhaust gas exhausted from an engine. Such filters become clogged with particulate matter as they continue to be used. Therefore, a regeneration process is performed in which the trapped soot is burned and removed from the filter by raising the temperature of the filter.

  When performing the regeneration process, if the oxygen in the exhaust gas is relatively small, combustion of soot is not promoted. Therefore, a technique for supplementing oxygen by injecting air into the exhaust path has been developed (for example, Patent Document 1).

JP 2003-314245 A

  There is a demand for the development of a technique for efficiently burning soot during the regeneration process.

  An object of the present invention is to provide an exhaust gas purification device capable of efficiently burning soot.

  In order to solve the above problems, an exhaust gas purification apparatus of the present invention includes an upstream exhaust pipe through which exhaust gas exhausted from an engine passes, a pipe connected to the downstream side of the upstream exhaust pipe, and a downstream of the pipe A downstream exhaust pipe connected to the side, and one or a plurality of filters that are provided in the tubular body and partition the tubular body into an upstream space that communicates with the upstream exhaust pipe and a downstream space that communicates with the downstream exhaust pipe The filter has an outer cylinder and a filter wall provided in the outer cylinder, and is provided in the pipe body so that the axial direction of the upstream exhaust pipe and the downstream exhaust pipe intersects with the axial direction of the outer cylinder. The part located in the upstream space in the outer cylinder, and the part within a predetermined range from the communication part between the upstream exhaust pipe and the tubular body is not in contact with the tubular body.

  The filter is disposed below the vehicle body of the vehicle on which the engine is mounted, and the communication portion between the pipe body and the downstream exhaust pipe may be separated from the vehicle body than the communication portion between the upstream exhaust pipe and the pipe body. Good.

  Further, at least two filters are provided in the pipe body, and the first filter and the second filter are arranged in series so that the exhaust gas introduced from the upstream exhaust pipe to the pipe body passes through the first filter. And the exhaust gas introduced into the pipe from the upstream exhaust pipe by arranging the first filter and the second filter in parallel and passing through the second filter to the downstream exhaust pipe is arranged in parallel. There may be provided a switching mechanism for switching to the parallel state of passing through the second filter or the second filter and leading to the downstream exhaust pipe.

  According to the present invention, soot can be burned efficiently.

It is the schematic which shows the structure of an engine system. It is the schematic which shows the structure of an exhaust-gas purification apparatus. It is a figure explaining GPF. It is the schematic which shows the structure of the filter unit of a 1st modification. It is the schematic which shows the structure of the exhaust-gas purification apparatus of a 2nd modification. It is a figure explaining a serial state and a parallel state.

  Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. The dimensions, materials, and other specific numerical values shown in the embodiments are merely examples for facilitating understanding of the invention, and do not limit the present invention unless otherwise specified. In the present specification and drawings, elements having substantially the same function and configuration are denoted by the same reference numerals, and redundant description is omitted, and elements not directly related to the present invention are not illustrated. To do.

  FIG. 1 is a schematic diagram showing the configuration of the engine system 100. In FIG. 1, the signal flow is indicated by broken arrows. As shown in FIG. 1, the engine system 100 is provided with an ECU (Engine Control Unit) 110 formed of a microcomputer including a central processing unit (CPU), a ROM storing programs and the like, a RAM as a work area, and the like. The ECU 110 performs overall control of the engine 120. However, the configuration and processing related to the present embodiment will be described in detail below, and the description of the configuration and processing unrelated to the present embodiment will be omitted. Here, a gasoline engine will be described as an example of the engine 120.

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

  An exhaust manifold 138 communicates with the exhaust port 136 of each cylinder 122 a formed in the cylinder block 122 of the engine 120. A muffler 142 is communicated with a collecting portion of the exhaust manifold 138 through an exhaust pipe 140. The exhaust pipe 140 is provided with an exhaust gas purification device 200 described later. Hereinafter, the exhaust pipe 140 that communicates the collecting portion of the exhaust manifold 138 and the filter unit 220 (described later) constituting the exhaust gas purification apparatus 200 is referred to as an upstream exhaust pipe 140a, and the exhaust that communicates the filter unit 220 and the muffler 142. The pipe 140 may be referred to as a downstream exhaust pipe 140b. 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 of the cylinders 122a so that the tip thereof is located in the combustion chamber 146. 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 that detects an intake air amount flowing into the engine 120 between an air cleaner 132 and a throttle valve 134 in the intake pipe 130, and air (outside air) that flows into the engine 120. An intake air temperature sensor 162 that detects the temperature is provided. 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 the 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 signal acquisition unit 180, the target value derivation unit 182, the air amount determination unit 184, the injection amount determination unit 186, the throttle opening determination unit 188, the ignition timing determination unit 190, and the drive control unit 192. Function as.

  The signal acquisition unit 180 acquires signals indicating values detected by the sensors 160 to 168. The target value deriving unit 182 derives the current engine speed based on the signal indicating the crank angle acquired from the crank angle sensor 166. Further, the target value deriving unit 182 refers to the pre-stored map based on the derived engine speed and a signal indicating the accelerator opening acquired from the accelerator opening sensor 168, and the target torque and the target engine speed. Is derived.

  The air amount determination unit 184 determines a 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 unit 182. The throttle opening determination unit 188 derives the total target air amount of each cylinder 122a determined by the air amount determination unit 184, and determines the target throttle opening for intake of the total amount of air from the outside.

  The injection amount determining unit 186 supplies each cylinder 122a based on the target engine speed and target torque derived by the target value deriving unit 182 and the target air amount of each cylinder 122a determined by the air amount determining unit 184. The target fuel injection amount is determined. Further, the injection amount determination unit 186 is based on a signal indicating the crank angle detected by the crank angle sensor 166 in order to inject the fuel of the determined target injection amount from the injector 150 in the intake stroke or compression stroke of the engine 120. The target injection timing and target injection period of each injector 150 are determined.

  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, etc., the ignition timing determining unit 190 is a spark plug 148 in each cylinder 122 a. The target ignition timing is determined.

  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 at the target injection timing and the target injection period determined by the injection amount determination unit 186, thereby causing the injector 150 to inject fuel of the target injection amount. Further, the drive control unit 192 ignites the spark plug 148 at the target ignition timing determined by the ignition timing determination unit 190.

  In this manner, the exhaust gas generated by burning the fuel in the combustion chamber 146 is discharged to the outside through the exhaust pipe 140. Since exhaust gas contains hydrocarbons (HC: Hydro Carbon), carbon monoxide (CO), nitrogen oxides (NOx), particulate matter such as soot, it is necessary to remove them. Therefore, an exhaust gas purification device 200 is provided in the exhaust pipe 140, and the exhaust gas purification device 200 removes hydrocarbons, carbon monoxide, nitrogen oxides, and particulate matter.

  When the ECU 110 functions as an exhaust gas purification device, the ECU 110 functions as a deposition amount estimation unit 194 and a supply control unit 196. The accumulation 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. In FIG. 2, the signal flow is indicated by a dashed arrow, and the vehicle body of the vehicle on which the engine 120 is mounted is indicated by an alternate long and short dash line. As shown in FIG. 2, the exhaust gas purification apparatus 200 includes a deposition amount estimation unit 194, a supply control unit 196, a three-way catalyst (Three-Way Catalyst) 210, a filter unit 220, and an oxygen-containing gas supply unit 230. Including. In the present embodiment, the exhaust gas purification device 200 is provided below the vehicle body.

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

  The filter unit 220 includes a tubular body 222 and a GPF (filter) 224. The pipe body 222 connects the upstream exhaust pipe 140a and the downstream exhaust pipe 140b. The upstream exhaust pipe 140a and the pipe body 222 are connected such that these communication portions 222a are located on the vehicle body side from the center of the cross section of the flow path of the pipe body 222. In addition, the pipe body 222 and the downstream exhaust pipe 140b are connected so that the communication portion 222b is located away from the vehicle body from the center of the cross section of the flow path of the pipe body 222.

  The GPF 224 is provided in the tube body 222. That is, the GPF 224 is provided on the downstream side of the three-way catalyst 210 in the exhaust pipe 140. The GPF 224 captures particulate matter (soot) in the exhaust gas exhausted from the exhaust port 136.

  FIG. 3 is a diagram for explaining the GPF 224. FIG. 3A is a perspective view of the GPF 224. FIG. 3B is a front view of the GPF 224. FIG. 3C is a YZ sectional view of the GPF 224. In FIG. 3A, the flow of exhaust gas is indicated by white arrows, and in FIG. 3C, the flow of exhaust gas is indicated by solid arrows. Further, in FIG. 3 of the present embodiment, the X axis, the Y axis (exhaust gas flow direction), and the Z axis that intersect perpendicularly are defined as illustrated. Further, in FIG. 3A to FIG. 3C, the cell 316 is shown larger than the outer cylinder 312 for easy understanding.

  As shown in FIGS. 3A to 3C, the GPF 224 is a wall flow type filter. The GPF 224 includes a filter unit 310, an upstream plug unit 320, and a downstream plug unit 330.

  The filter unit 310 includes a cylindrical outer cylinder 312 and a filter wall 314 through which exhaust gas passes. The outer cylinder 312 is made of ceramic, for example.

  The filter wall 314 is made of ceramic, for example. The filter wall 314 has a plurality of holes through which exhaust gas passes while capturing particulate matter contained in the exhaust gas. In FIG. 3, the filter wall 314 is provided on a plane parallel to the XY plane, the first wall 314a extending in the Y axis direction, and provided on a plane parallel to the YZ plane, and in the Y axis direction. And an extending second wall 314b. Then, as shown in FIG. 3B, the space surrounded by the two first walls 314a and the two second walls 314b, or the first wall 314a, the second wall 314b, and the outer cylinder 312 is surrounded. A space is formed as a cell 316.

  Therefore, the plurality of cells 316 extend in the axial direction (Y-axis direction in FIG. 3) of the outer cylinder 312 in the outer cylinder 312 (filter unit 310) and in a direction orthogonal to the axial direction (in FIG. 3). , X axis direction and Z axis direction). In GPF 224, cells 316A classified into the first cell group and cells 316B classified into the second cell group are alternately arranged. That is, the cells 316A and the cells 316B are alternately arranged adjacent to each other.

  As shown in FIG. 3C, the upstream plug portion 320 seals the upstream opening 318a on the upstream side of the cell 316A that is classified into the first cell group among the cells 316. The upstream plug portion 320 is made of, for example, ceramic.

  As shown in FIG. 3C, the downstream plug portion 330 seals the downstream opening 318b on the downstream side of the cell 316B (classified as the second cell group) other than the cell 316A. The downstream plug portion 330 is made of ceramic, for example.

  In the present embodiment, the GPF 224 has a function of capturing particulate matter, a function as a three-way catalyst for purifying exhaust gas, and a function as OSC (Oxygen Storage capacity). More specifically, the filter wall 314 constituting the GPF 224 carries the catalyst component constituting the three-way catalyst and the OSC material.

As described above, the exhaust gas purifying apparatus 200 can remove the particulate matter from the exhaust gas by depositing the particulate matter on the GPF 224 by the configuration including the GPF 224 in the exhaust pipe 140. Then, the particulate matter (carbon C) deposited on the GPF 224 is removed from the GPF 224 by a reaction (oxidation reaction of the particulate matter) represented by 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 that the stoichiometric air-fuel ratio (stoichiometric) is obtained. In the operation at the stoichiometric air-fuel ratio, the oxygen contained in the exhaust gas has a low concentration, so that the regeneration process of the GPF 224 is not promoted.

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

  Returning specifically to FIG. 2, the oxygen-containing gas supply unit 230 includes a supply pipe 232 and a pump 234. The supply pipe 232 is connected between the three-way catalyst 210 and the pipe body 222 (GPF 224) in the upstream exhaust pipe 140a, and the end thereof is opened to the atmosphere. The pump 234 is provided in the supply pipe 232 and supplies outside air (oxygen-containing gas) to the supply pipe 232.

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

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

  In this way, by supplying the outside air and executing the regeneration process, the particulate matter (soot) deposited on the GPF 224 is efficiently burned. The exhaust gas purification apparatus 200 of this embodiment devisees the arrangement of the GPF 224 with respect to the upstream exhaust pipe 140a, and thereby burns particulate matter more efficiently in the regeneration process.

  As shown in FIG. 2, the GPF 224 partitions the inside of the tubular body 222 into an upstream space U and a downstream space D. Here, the upstream space U is a space communicating with the upstream exhaust pipe 140 a in the tube body 222. The downstream space D is a space communicating with the downstream exhaust pipe 140b in the tube body 222. The GPF 224 is provided in the pipe body 222 so that the upstream opening 318a of the cell faces the upstream space U and the downstream opening 318b of the cell faces the downstream space D.

  Further, in the present embodiment, the GPF 224 is formed such that the axial length of the outer cylinder 312 is smaller than the inner diameter of the outer cylinder 312, the axial direction of the upstream exhaust pipe 140 a and the downstream exhaust pipe 140 b, and the outer cylinder 312. The tube body 222 is provided so as to intersect with the axial direction. For example, the GPF 224 is arranged in the tubular body 222 so that the axial direction of the outer cylinder 312 is the vertical direction, or the axial direction of the outer cylinder 312 is inclined more than 0 degrees and less than 45 degrees upstream from the vertical direction. Is provided.

  Therefore, the vertical width of the tubular body 222 is kept small as compared with the conventional technique in which the GPF 224 is provided so that the axial direction is the horizontal direction (parallel to the axial direction of the upstream exhaust pipe 140a and the downstream exhaust pipe 140b). , The cross-sectional area of the GPF 224 (the inner diameter of the outer cylinder 312) can be increased. Accordingly, the GPF 224 having a relatively large flow path cross-sectional area can be disposed at a place where the space is limited, such as below the vehicle body. Further, by making the flow path cross-sectional area of the GPF 224 relatively large, the pressure loss can be made lower than that of the GPF 224 having a small flow path cross-sectional area. Thereby, fuel consumption can be improved.

  The GPF 224 is supported by a stopper (not shown). The stopper is provided below the GPF 224 and extends from the tube body 222. Further, the gap between the lower part of the GPF 224 and the tube body 222 (stopper) is filled with ceramic wool having heat resistance.

  Further, the GPF 224 of the present embodiment is provided in the tubular body 222 such that the most upstream and vertically upper portion M of the outer cylinder 312 is not in contact with the tubular body 222 and faces the communicating portion 222a.

  Then, the high-temperature exhaust gas flowing through the upstream exhaust pipe 140a first comes into contact with the part M. Therefore, the part M can efficiently accumulate the heat of the exhaust gas during normal operation (when the regeneration process is not executed). Further, since the portion M is not in contact with the tube body 222, it is possible to avoid the accumulated heat from being radiated to the outside through the tube body 222.

  In this way, by accumulating heat at the part M during normal operation, the part M reaches the highest temperature before the regeneration process is started. When the pump 234 is driven and external air is supplied to execute the regeneration process, the external air reaches the GPF 224 through the upstream exhaust pipe 140a and the communication portion 222a. Here, as described above, since the part M faces the communication part 222a, the outside air first reaches the part M in the GPF 224. Then, the particulate matter accumulated in the GPF 224 starts to burn from the vicinity of the part M, and then spreads to the downstream side. Here, since the part M has the highest temperature in the GPF 224, the ignitability of the particulate matter in the vicinity of the part M can be improved. Therefore, the combustibility of the particulate matter can be further improved in the regeneration process as compared with the conventional technique in which the outer cylinder 312 of the GPF 224 is in contact with the pipe body 222.

  Further, as described above, the communication part 222a is provided on the vehicle body side, the communication part 222b is provided in a direction away from the vehicle body, and the cells 316 are connected to the communication part 222a and the communication part 222b (the upstream space U and the downstream space D). ). Therefore, outside air flows in a direction away from the vehicle body from the vehicle body side. Then, the particulate matter deposited on the GPF 224 starts to burn from the vicinity of the part M, and then spreads in the downstream side and in the direction away from the vehicle body.

  Therefore, in the exhaust gas purification apparatus 200, the combustion heat propagates in a direction away from the vehicle body in the GPF 224. For this reason, when the regeneration process is executed, in the exhaust gas purifying apparatus 200, the most downstream and vertically lower portion N of the outer cylinder 312 of the GPF 224 has the heat propagated from the upstream side and the vehicle body side, and the particulate matter Combined with combustion heat, it becomes the highest temperature.

  In this way, the portion that becomes the highest temperature when the regeneration process is executed can be set at a position separated from the vehicle body. Thereby, propagation of heat generated in the regeneration process to the vehicle body can be suppressed. Therefore, the influence on the vehicle body due to heat can be suppressed.

(First modification)
In the above embodiment, the configuration in which one GPF 224 is provided in the tubular body 222 has been described as an example. However, the number of GPFs 224 is not limited.

  FIG. 4 is a schematic diagram showing the configuration of the filter unit 420 of the first modification. In addition, in FIG. 4, a vehicle body is shown with a dashed-dotted line. In addition, components that are substantially the same as the filter unit 220 of the exhaust gas purification device 200 are given the same reference numerals, and descriptions thereof are omitted.

  The filter unit 420 is different from the filter unit 220 only in that two GPFs 224 (indicated by 224A and 224B in FIG. 4) are provided in the tube body 222.

  More specifically, the GPF 224A located on the upstream side and the GPF 224B located on the downstream side in the tubular body 222 are arranged so that the outer cylinders 312 are in contact with each other and the axial directions of the outer cylinders 312 are parallel to each other. 222 is provided.

  Further, the GPFs 224A and 224B are provided in the pipe body 222 so that the axial directions of the upstream exhaust pipe 140a and the downstream exhaust pipe 140b intersect the axial direction of the outer cylinder 312. For example, the GPFs 224A and 224B have a tubular body so that the axial direction of the outer cylinder 312 is a vertical direction, or the axial direction of the outer cylinder 312 is inclined more than 0 degree and more than 45 degrees upstream from the vertical direction. 222 is provided.

  Further, the GPF 224A is provided in the tubular body 222 so that the most upstream and vertically upper portion M of the outer cylinder 312 is not in contact with the tubular body 222 and faces the communication portion 222a. Thereby, like the filter unit 220, the part M can efficiently accumulate the heat of the exhaust gas during the normal operation. Further, since the portion M is not in contact with the tube body 222, it is possible to avoid the accumulated heat from being radiated to the outside through the tube body 222.

  The GPFs 224A and 224B partition the inside of the tubular body 222 into an upstream space U and a downstream space D. The GPFs 224A and 224B are provided in the pipe body 222 so that the upstream opening 318a of the cell faces the upstream space U and the downstream opening 318b of the cell faces the downstream space D.

  As described above, the communication location 222a is provided on the vehicle body side, the communication location 222b is provided in a direction away from the vehicle body, and the cells 316 of the GPFs 224A and 224B are connected to the communication location 222a and the communication location 222b (the upstream space U and Communicate with downstream space D). Therefore, outside air flows in a direction away from the vehicle body from the vehicle body side. Then, the particulate matter deposited on the GPF 224 starts to burn from the vicinity of the part M, and then spreads in the downstream side and in the direction away from the vehicle body.

  Therefore, also in the filter unit 420, the combustion heat propagates in a direction away from the vehicle body in the GPFs 224A and 224B, as in the filter unit 220. For this reason, when the regeneration process is executed, the most downstream and vertically downward portion N of the outer cylinder 312 of the GPFs 224A and 224B is combined with the heat propagated from the upstream side and the vehicle body side and the combustion heat of the particulate matter. The highest temperature.

  In this way, the portion that becomes the highest temperature when the regeneration process is executed can be set at a position separated from the vehicle body. Thereby, propagation of heat generated in the regeneration process to the vehicle body can be suppressed. Therefore, the influence on the vehicle body due to heat can be suppressed. Further, unlike the filter unit 220, the existing GPF 224 can be adopted for the filter unit 420 of the first modified example.

(Second modification)
FIG. 5 is a schematic diagram showing a configuration of an exhaust gas purifying apparatus 500 of a second modification. In FIG. 5, the signal flow is indicated by broken arrows, and the vehicle body is indicated by a one-dot chain line. Further, in FIG. 5, the three-way catalyst 210 and the oxygen-containing gas supply unit 230 are omitted for easy understanding. In addition, components that are substantially the same as the filter unit 220 and the filter unit 420 of the exhaust gas purification device 200 are given the same reference numerals, and descriptions thereof are omitted.

  The exhaust gas purification apparatus 500 includes a deposition amount estimation unit 194, a supply control unit 196, a switching control unit 590, a three-way catalyst 210, a filter unit 520, a first valve (switching mechanism) 530, and a second valve. (Switching mechanism) 540 and oxygen-containing gas supply unit 230 are included. The exhaust gas purification device 500 is provided below the vehicle body.

  Similarly to the filter unit 420, the filter unit 520 is provided with two GPFs 224 (indicated by 224A and 224B in FIG. 5) in the tube body 222. In the GPF 224 </ b> B located on the downstream side, unlike the filter unit 420, the outer cylinder 312 is separated from the tube body 222 and provided in the tube body 222. The GPFs 224A and 224B are provided in the tubular body 222 so that the axial direction of the outer cylinder 312 is the vertical direction.

  The first valve 530 is provided in the upstream space U. The first valve 530 has a rotating shaft 532 and a valve body 534. The rotating shaft 532 is provided on a portion of the tubular body 222 that divides the upstream space U, specifically on the upper surface of the tubular body 222. The valve body 534 is connected to the rotation shaft 532 and is rotatable by the rotation shaft 532. The tip of the valve body 534 can come into contact with a contact portion (specifically, an upper end of the contact portion) between the outer cylinder 312 of the GPF 224A and the outer cylinder 312 of the GPF 224B.

  The first valve 530 has a first state in which the valve body 534 is in contact with a contact location of the outer cylinder 312 and a first state where the valve body 534 is separated from the contact location of the outer cylinder 312 by a switching control unit 590 described later. Switch to 2 state.

  The second valve 540 is provided in a communication space between the upstream space U and the downstream space D. The second valve 540 has a rotating shaft 542 and a valve body 544. The rotating shaft 542 is provided on the downstream side of the outer cylinder 312 of the GPF 224B. The valve body 544 is connected to the rotation shaft 542 and is rotatable by the rotation shaft 542. The valve body 544 has a distal end capable of coming into contact with a portion 222 u that partitions the upstream space U in the tube body 222 and a portion 222 d that partitions the downstream space D in the tube body 222.

  The switching control unit 590 switches the second valve 540 between a third state in which the valve body 544 is in contact with the portion 222u and a fourth state in which the valve body 544 is in contact with the portion 222d.

  The switching control unit 590 sets the first valve 530 in the first state, the second valve 540 in the fourth state, the first valve 530 in the second state, and the second valve 540 in the third state. Switch to parallel state.

  FIG. 6 is a diagram illustrating a series state and a parallel state. FIG. 6A is a diagram illustrating the serial state. FIG. 6B illustrates the parallel state. In FIGS. 6A and 6B, the flow of exhaust gas (or outside air) is indicated by solid arrows.

  As shown in FIG. 6A, the switching control unit 590 assumes that the first valve 530 is in the first state and the second valve 540 is in the fourth state. Then, the exhaust gas introduced into the pipe body 222 from the upstream exhaust pipe 140a first passes through the GPF 224A (first filter) from the upper side to the lower side (in a direction away from the vehicle body) and reaches the downstream space D. To do. Thereafter, the exhaust gas that has reached the downstream space D passes through the GPF 224B (second filter) from below to above (in a direction close to the vehicle body). And the exhaust gas which passed GPF224B is guide | induced to the downstream exhaust pipe 140b through the communication location 222b. That is, in the serial state, GPF 224A and GPF 224B are arranged in series, and the exhaust gas introduced into the pipe body 222 from the upstream exhaust pipe 140a is passed through the GPF 224A and then passed through the GPF 224B to be led to the downstream exhaust pipe 140b. It can be said.

  Further, as illustrated in FIG. 6B, the switching control unit 590 assumes that the first valve 530 is in the second state and the second valve 540 is in the third state. Then, the exhaust gas introduced into the pipe body 222 from the upstream exhaust pipe 140a passes through one of the GPF 224A and GPF 224B from the upper side to the lower side (in a direction away from the vehicle body) and reaches the downstream space D. Thereafter, the exhaust gas reaching the downstream space D is guided to the downstream exhaust pipe 140b through the communication portion 222b. That is, it can be said that the parallel state is a state in which the GPF 224A and the GPF 224B are arranged in parallel and the exhaust gas introduced from the upstream exhaust pipe 140a into the pipe body 222 is passed through the GPF 224A or GPF 224B and guided to the downstream exhaust pipe 140b.

  In this manner, the switching control unit 590 controls the first valve 530 and the second valve 540 to switch the exhaust gas passage path between the series state and the parallel state. For example, the switching control unit 590 switches to the serial state when the engine 120 is started or when regeneration processing is executed. Since the concentration of particulate matter in the exhaust gas is relatively high when the engine 120 is started, the particulate matter can be efficiently captured by the GPFs 224A and 224B by setting the exhaust gas passage route in series. it can. In addition, when the regeneration process is executed, the combustion state can be efficiently started by setting the most upstream and vertical upper portion M of the outer cylinder 312 of the GPF 224A as the ignition point by setting the state in series. Further, since the outside air heated by the GPF 224A is supplied to the GPF 224B, the GPF 224B can start combustion efficiently. Furthermore, components that could not be purified by GPF 224A can be purified by GPF 224B.

  Further, the switching control unit 590 switches the exhaust gas passage route to a parallel state when the engine 120 has been warmed up or when the engine 120 has a high load. Thereby, the pressure loss by GPF224A, 224B can be reduced compared with a serial state.

  As mentioned above, although preferred embodiment of this invention was described referring an accompanying drawing, it cannot be overemphasized that this invention is not limited to this embodiment. It will be apparent to those skilled in the art that various changes and modifications can be made within the scope of the claims, and these are naturally within the technical scope of the present invention. Is done.

  In the embodiment and the modification described above, the configuration in which the ECU 110 functions as the accumulation amount estimation unit 194, the supply control unit 196, and the switching control unit 590 has been described as an example. However, the accumulation amount estimation unit 194, the supply control unit 196, and the switching control unit 590 may be configured separately from the ECU 110.

  Moreover, in the said embodiment and modification, the wall flow type filter was mentioned as an example and demonstrated as GPF224. However, the GPF 224 only needs to have at least the outer cylinder 312 and the filter wall, and the configuration is not limited.

  In the above-described embodiment and the modification, the GPF 224 is described as an example of the configuration including the catalyst. However, the GPF 224 may be capable of capturing the particulate matter and may not include the catalyst.

  In the above-described embodiment and modification, the communication portion 222a between the upstream exhaust pipe 140a and the tube body 222 is located on the vehicle body side, and the communication portion 222b between the tube body 222 and the downstream exhaust pipe 140b is from the communication portion 222a. As an example, the case of being separated from the vehicle body has been described. However, the communication location 222a may be further away from the vehicle body than the communication location 222b. Further, the communication location 222a and the communication location 222b may be at the same position, that is, the upstream exhaust pipe 140a and the downstream exhaust pipe 140b may be coaxial.

  In the above-described embodiment and the modification, the configuration in which the most upstream portion M in the outer cylinder 312 is vertically in contact with the tubular body 222 has been described as an example. However, the part located in the upstream space U in the outer cylinder 312 and a part within a predetermined range from the communication part 222 a may be in non-contact with the tubular body 222. For example, the part located in the upstream space U on the side of the communication portion 222 a of the outer cylinder 312 may be in non-contact with the tubular body 222.

  In the exhaust gas purifying apparatus 500 of the second modified example, the case where the switching mechanism includes the first valve 530 and the second valve 540 has been described as an example. However, the switching mechanism includes a serial state in which the exhaust gas introduced into the pipe body 222 from the upstream exhaust pipe 140a is passed through the first filter and then passed through the second filter to be led to the downstream exhaust pipe 140b. The configuration is not limited as long as it can be switched to the parallel state of passing through the first filter and passing through the second filter in parallel with the first filter and leading to the downstream exhaust pipe 140b.

  Moreover, in the said embodiment and modification, the case where the oxygen containing gas supply part 230 supplies external air as an oxygen containing gas was mentioned as an example, and was demonstrated. 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 stoichiometric air-fuel ratio exhaust gas.

  Moreover, in the said embodiment, the gasoline engine was mentioned as an example and demonstrated as the engine 120. FIG. However, the exhaust gas purification devices 200 and 500 are not limited to the type of engine (for example, a diesel engine), and can remove particulate matter contained in the exhaust gas exhausted from the engine.

  The present invention can be used for an exhaust gas purification device.

140a Upstream exhaust pipe 140b Downstream exhaust pipe 200, 500 Exhaust gas purification device 222 Pipe body 224 GPF (filter)
312 outer cylinder 314 filter wall 316, 316A, 316B cell 318a upstream opening 318b downstream opening 530 first valve (switching mechanism)
540 Second valve (switching mechanism)
590 switching control unit (switching mechanism)

Claims (3)

An upstream exhaust pipe through which exhaust gas exhausted from the engine passes,
A pipe connected to the downstream side of the upstream exhaust pipe;
A downstream exhaust pipe connected to the downstream side of the tubular body;
One or a plurality of filters provided in the pipe body and partitioning the pipe body into an upstream space communicating with the upstream exhaust pipe and a downstream space communicating with the downstream exhaust pipe;
With
The filter is
An outer cylinder, and a filter wall provided in the outer cylinder,
Provided in the tube so that the axial direction of the upstream exhaust pipe and the downstream exhaust pipe intersects the axial direction of the outer cylinder,
An exhaust gas purifying apparatus, wherein a part of the outer cylinder located in the upstream space and in a predetermined range from a communication part between the upstream exhaust pipe and the pipe body is not in contact with the pipe body. The filter is disposed below a vehicle body of a vehicle on which the engine is mounted,
The exhaust gas purification device according to claim 1, wherein a communication portion between the pipe body and the downstream exhaust pipe is further away from the vehicle body than a communication portion between the upstream exhaust pipe and the pipe body. In the tube, at least two of the filters are provided,
The first filter and the second filter are arranged in series so that the exhaust gas introduced from the upstream exhaust pipe into the pipe body passes through the first filter and then passes through the second filter. The exhaust gas introduced from the upstream exhaust pipe into the tubular body by arranging the first filter and the second filter in parallel, and leading the downstream exhaust pipe to the downstream exhaust pipe. The exhaust gas purifying apparatus according to claim 1 or 2, further comprising a switching mechanism that switches to a parallel state of passing through the second filter and leading to the downstream exhaust pipe.

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