JP6890735B2 - Exhaust gas treatment device - Google Patents

Description

The present invention relates to an exhaust gas treatment device.

Patent Document 1 describes an air-fuel ratio sensor that detects the oxygen concentration in the exhaust gas that has passed through the catalytic converter in an exhaust passage in which a catalytic converter and a DPF (diesel particulate filter) are provided in a straight line. The configuration to be provided is disclosed.

Japanese Unexamined Patent Publication No. 2008-075458

By the way, the conventional exhaust gas treatment device arranged near the internal combustion engine is required to be small due to the limitation of the mounting space while mounting a plurality of catalysts in order to comply with the exhaust gas regulations, and the exhaust gas that has passed through the catalyst is further required. The gas components had to be measured with high accuracy, and it was difficult to configure the exhaust gas treatment device to satisfy these requirements.

The present invention proposes a compact exhaust gas treatment device capable of measuring an exhaust gas component with high accuracy while mounting a plurality of catalysts.

According to an aspect of the present invention, the exhaust gas treatment device is arranged on the upstream side of the first catalyst carrier for purifying the exhaust gas flowing along the first direction and the first catalyst carrier, and heats the exhaust gas. An electrothermal catalyst having a heater, a second catalyst carrier that purifies the exhaust gas that has passed through the first catalyst carrier and flows along the second direction intersecting the first direction, and the first catalyst carrier. A case for accommodating the second catalyst carrier, a sensor having a measuring unit for measuring the exhaust gas and measuring the exhaust gas passing through the first catalyst carrier, and an outer peripheral surface of the first catalyst carrier. The outer peripheral flow path provided between the inner peripheral surface of the case and covering the outer periphery of the first catalyst carrier, and the exhaust gas formed by the case protruding inward and passing through the first catalyst carrier are referred to as the first catalyst carrier. 2 The catalyst carrier and a branch portion that branches so as to lead to each of the outer peripheral flow paths are provided, and the measurement unit included in the sensor is a downstream end surface of the first catalyst carrier and an upstream side of the second catalyst carrier. A region surrounded by an end face and an inner wall surface that receives exhaust gas that has passed through the first catalyst carrier in the case, and is arranged in a region closer to the second catalyst carrier than the center of the first catalyst carrier, and the measurement is performed. The portion is arranged in a region where exhaust gas flows from the branch portion toward the second catalyst carrier, and the angle formed by the top of the branch portion is 70 ° to 120 °.

In the above aspect, it is a region surrounded by the downstream end surface of the first catalyst carrier, the upstream end surface of the second catalyst carrier, and the inner wall surface of the case, and is located in a region closer to the second catalyst carrier than the center of the first catalyst carrier. The measurement unit of the sensor is located. In the region where the measurement unit of this sensor is arranged, the mainstream of the exhaust gas flow from the first catalyst carrier to the second catalyst carrier is formed while the exhaust gas passing through the first catalyst carrier collides with the inner wall surface of the case. Therefore, the flow velocity of the exhaust gas becomes relatively high. Therefore, the exhaust gas is purified by arranging the first catalyst carrier and the second catalyst carrier so that the flow direction of the exhaust gas flowing through the first catalyst carrier and the flow direction of the exhaust gas flowing through the second catalyst carrier intersect with each other. The exhaust gas treatment device can be downsized while ensuring sufficient performance, and even in such a configuration, the exhaust gas can be detected with high accuracy by the sensor that measures the exhaust gas.

FIG. 1 is a side view of the exhaust gas treatment device according to the first embodiment of the present invention. FIG. 2 is a rear view of the exhaust gas treatment device according to the first embodiment of the present invention. FIG. 3 is a cross-sectional view taken along the line III-III of FIG. FIG. 4 is a cross-sectional view taken along the line IV-IV of FIG. FIG. 5 is a cross-sectional view taken along the line VV of FIG. FIG. 6 is a cross-sectional view taken along the line VI-VI of FIG. FIG. 7 is a partial perspective view showing the flow of exhaust gas in the case of the exhaust gas treatment device. FIG. 8 is a front view of the exhaust gas treatment device according to the modified example of the first embodiment of the present invention. FIG. 9 is a cross-sectional view taken along the line IX-IX of FIG. FIG. 10 is a side view of the exhaust gas treatment device according to the modified example of the first embodiment of the present invention. FIG. 11 is a cross-sectional view taken along the line XI-XI of FIG. FIG. 12 is a cross-sectional view of a side surface of an exhaust gas treatment device according to another modification of the first embodiment of the present invention. FIG. 13 is a diagram showing the results of simulating the flow of exhaust gas from the first catalyst carrier to the second catalyst carrier of the exhaust gas treatment apparatus according to the first embodiment of the present invention. FIG. 14 is a diagram showing a list of the results of simulating the flow of exhaust gas from the first catalyst carrier to the second catalyst carrier in each variation of the exhaust gas treatment apparatus. FIG. 15A is a diagram showing the results of simulating the flow of exhaust gas from the first catalyst carrier to the second catalyst carrier of the exhaust gas treatment apparatus. FIG. 15B is a diagram showing the results of simulating the flow of exhaust gas from the first catalyst carrier to the second catalyst carrier of the exhaust gas treatment apparatus. FIG. 16 is a cross-sectional view of a side surface of the exhaust gas treatment device according to the second embodiment of the present invention.

Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.

(First Embodiment)
The exhaust gas treatment device 10 according to the first embodiment of the present invention will be described with reference to FIGS. 1 to 7. FIG. 1 is a side view showing an exhaust gas treatment device 10 according to the first embodiment. FIG. 2 is a rear view of the exhaust gas treatment device 10. FIG. 3 is a cross-sectional view taken along the line III-III in FIG. 1 of the exhaust gas treatment device 10. FIG. 4 is a cross-sectional view taken along the line IV-IV of FIG. 1 of the exhaust gas treatment device 10. FIG. 5 is a cross-sectional view of the exhaust gas treatment device 10 along the line VV in FIG. FIG. 6 is a cross-sectional view of the exhaust gas treatment device 10 along the VI-VI line in FIG. FIG. 7 is a partial perspective view showing the flow of the exhaust gas G in the case 30 of the exhaust gas treatment device 10.

The exhaust gas treatment device 10 is mounted on a vehicle, for example, and treats the exhaust gas G discharged from an engine (not shown). In the following embodiment, the catalyst is small and has excellent exhaust gas purification performance. An example of the structure as a converter is shown. Specifically, the exhaust gas treatment device 10 oxidizes hydrocarbons and carbon monoxide contained in the exhaust gas G to carbon dioxide and water, reduces nitrogen oxides, and removes fine particulate matter. And purify the exhaust gas G.

As shown in FIGS. 1 to 5, the exhaust gas treatment device 10 has an exhaust pipe (not shown) that guides the inlet side flange 11 connected to the exhaust outlet portion of the exhaust turbine (not shown) and the exhaust gas G to the outside. ), TWC (three-way catalyst) 12 as a first catalyst carrier provided in the case 30 and purifying the exhaust gas G, and downstream of the TWC 12 in the case 30. GPF (gasoline particulate filter) 14 as a second catalyst carrier that is provided on the side and purifies the exhaust gas G that has passed through the TWC 12, and as a sensor for measuring the oxygen concentration of the exhaust gas G that has passed through the TWC 12. The air-fuel ratio sensor 40 is provided.

The case 30 includes a diffuser portion 25 to which the inlet-side flange 11 is attached, an inlet-side tubular portion 31 for accommodating the TWC 12 inside, an intermediate tubular portion 37 joined to the inlet-side tubular portion 31 and accommodating the GPF 14 inside, and one end. Is joined to the intermediate cylinder portion 37, and has an outlet side cylinder portion 38 provided with an outlet side flange 39 for connecting to an exhaust side pipeline (not shown) at the other end.

As shown in FIGS. 4 and 5, the diffuser portion 25 is formed by a conical diffuser plate 26 whose diameter gradually increases toward the downstream side. The inlet side flange 11 is attached to the outer peripheral surface of the upstream side opening 26a of the diffuser plate 26 by welding or the like. The downstream opening 26b of the diffuser plate 26 is attached to the inner peripheral surface of the inlet opening 31a of the inlet cylinder 31 by welding or the like.

As shown in FIG. 5, the inlet-side tubular portion 31 has an inlet-side opening 31a into which the exhaust gas G flows in and an outlet-side opening 31b in which the exhaust gas G flows out. The inlet-side tubular portion 31 is configured to bend the flow of the exhaust gas G passing through the inlet-side tubular portion 31 by a predetermined angle (for example, 90 °), that is, to form a substantially L-shaped flow path. To. The inlet-side tubular portion 31 is formed by joining two metal plate-shaped members symmetrically formed along the flow direction of the exhaust gas G by welding or the like (see FIGS. 2 to 4).

As shown in FIG. 6, the intermediate tubular portion 37 is formed in an elliptical tubular shape by a metal plate-shaped member. As shown in FIG. 5, the outer peripheral surface of the inlet-side opening 37a of the intermediate cylinder 37 is joined to the inner peripheral surface of the outlet-side opening 31b of the inlet-side cylinder 31 by welding or the like. Further, the outer peripheral surface of the outlet side opening 37b of the intermediate cylinder portion 37 is joined to the inner peripheral surface of the inlet side opening 38a of the outlet side cylinder portion 38 by welding or the like.

The TWC 12 is composed of, for example, a columnar honeycomb structure. The outer peripheral surface 12a of the TWC 12 is fitted into a tubular inner case 20 made of metal via a cushioning material 13. The TWC 12 is housed in the inner case 20 over the entire axial direction.

In the inner case 20, the upstream opening 20b is inserted into the inner circumference of the downstream opening 26b in the diffuser plate 26. The inner case 20 is fixed to the case 30 by being joined to the inner peripheral surface of the diffuser plate 26 by welding or the like. At this time, the inner case 20 is provided in the case 30 so that a gap of a predetermined distance W is provided between the outer peripheral surface 20a of the inner case 20 and the inlet side tubular portion 31. This gap forms an outer peripheral flow path 35 through which the exhaust gas G flows. Further, as shown in FIG. 3, a plurality of spacers 34 for preventing rattling of the inner case 20 are provided between the outer peripheral surface 20a of the inner case 20 and the inlet side tubular portion 31.

In this way, the upstream opening 20b of the inner case 20 is joined to the downstream opening 26b of the diffuser plate 26, so that the total amount of the exhaust gas G flowing in from the exhaust inlet 11a of the inlet flange 11 is guided to the TWC 12. be able to.

GPF14 is composed of, for example, an elliptical columnar ceramic filter that removes fine particulate matter (see FIGS. 4 and 6). The GPF 14 is fixed in the intermediate cylinder portion 37 by fitting its outer peripheral surface 14a to the inner peripheral surface of the intermediate cylinder portion 37 via the cushioning material 15. As a result, the TWC 12 and the GPF 14 are arranged in a so-called T-shape in a side view.

Further, the flow path cross-sectional area of the GPF 14 is formed to be larger than the flow path cross-sectional area of the TWC 12. At this time, as shown in FIG. 4, the GPF 14 is provided in the intermediate cylinder portion 37 so that the major axis is located in the axial direction of the TWC 12. By arranging in this way, for example, even when a space cannot be secured in the width direction (vertical direction in FIG. 4) of the exhaust gas treatment device 10, the flow path cross-sectional area of the GPF 14 can be secured.

The outlet-side tubular portion 38 guides the exhaust gas G that has passed through the GPF 14 to an exhaust pipe (not shown) that discharges the exhaust gas G to the outside. The outlet side tubular portion 38 is formed by joining two metal plate-shaped members symmetrically formed along the flow direction of the exhaust gas G by welding or the like.

The air-fuel ratio sensor 40 has a rod-shaped member, and a measuring unit 41 for measuring the exhaust gas G is provided at the tip thereof. The main body portion of the air-fuel ratio sensor 40 is attached to the flat surface portion 31d provided on the inlet side tubular portion 31 from the outside of the case 30 so that the measuring unit 41 is located on the flow path between the TWC 12 and the GPF 14. The detailed mounting position of the air-fuel ratio sensor 40 will be described in detail later.

Subsequently, a more detailed configuration of the inlet side tubular portion 31 will be described. In the following, the direction in which the exhaust gas G passes through the TWC 12, that is, the axial direction of the TWC 12 is referred to as the "first direction P", and the direction in which the exhaust gas G passes through the GPF 14, that is, the axial direction of the GPF 14 is referred to as the "first direction P". It is called "two-way Q" (see FIG. 5). In this embodiment, the case where the first direction P and the second direction Q are orthogonal to each other is taken as an example, but it is not always necessary that the first direction P and the second direction Q are orthogonal to each other, and the first direction P and the second direction Q intersect. I just need to be there.

The inlet side cylinder portion 31 is provided on the inner wall surface 31c of the inlet side cylinder portion 31 that receives the exhaust gas G that has passed through the TWC 12, and is a branch portion that branches a part of the exhaust gas G that has passed through the TWC 12 so as to be guided to the GPF 14. 33 is further provided with a guide portion 32 for guiding the remaining exhaust gas G branched by the branch portion 33 to the outer peripheral flow path 35.

The branch portion 33 is formed in a shape in which a part of the pipe wall outside the flow direction of the exhaust gas G in the inlet side tubular portion 31 projects in the inner diameter direction. The angle α formed by the top portion 33a of the branch portion 33 is preferably about 70 ° to 120 °. If the angle α is less than 70 °, it becomes difficult to process the inlet side tubular portion 31. On the other hand, if the angle α is larger than 120 °, the flow rate of the exhaust gas G guided to the outer peripheral flow path 35 may not be sufficiently secured.

As shown in FIG. 5, the guide portion 32 has an inclined portion 32a inclined at a predetermined angle θ from the branch portion 33 to the downstream side in the first direction P with respect to the plane X orthogonal to the first direction P, and the inclined portion. It has a curved portion 32b that guides the exhaust gas G that has passed through 32a to the outer peripheral flow path 35.

The inclined portion 32a is formed in a substantially flat shape, and is formed so that a predetermined angle θ formed by the plane Y including the inclined portion 32a and the plane X is between 3 ° and 20 °. By setting the predetermined angle θ to such an angle, the exhaust gas G branched by the branch portion 33 is gently guided to the curved portion 32b and guided to the outer peripheral flow path 35 along the inner wall surface 31c of the case 30. Can be done. Therefore, the exhaust gas G can be smoothly guided to the outer peripheral flow path 35 without obstructing the flow of the exhaust gas G passing through the TWC 12 and toward the branch portion 33.

Further, when the TWC 12 and the GPF 14 are viewed from the directions orthogonal to the first direction P and the second direction Q (see FIG. 4, hereinafter also referred to as “third direction R”) (the state shown in FIG. 5). ), Both ends of the TWC 12 in the first direction P are located between both ends of the GPF 14 in the first direction P (see FIGS. 4 and 5). As a result, the TWC 12 does not protrude from the GPF 14 to the outside of the first direction P, so that the exhaust gas treatment device 10 can be miniaturized.

Next, the flow of the exhaust gas G in the exhaust gas treatment device 10 will be described.

As shown in FIG. 5, the exhaust gas G flowing in from the exhaust inlet 11a of the inlet side flange 11 is guided to the TWC 12 through the diffuser portion 25. In the exhaust gas G flowing into the TWC 12, hydrocarbons and carbon monoxide contained therein are oxidized and decomposed into carbon dioxide and water, and nitrogen oxides are reduced.

The exhaust gas G that has passed through the TWC 12 flows directly toward the upstream end surface 14b of the GPF 14 by the branch portion 33 formed on the inner wall surface 31c of the inlet side tubular portion 31, and passes through the guide portion 32 to the outer peripheral flow path 35. It is divided into the flow to go and the flow.

The flow directly toward the upstream end surface 14b of the GPF 14 forms the main flow of the exhaust gas G, is turned approximately 90 ° by the branch portion 33, and is directly directed to the upstream end surface 14b of the GPF 14 without wrapping around to the outer peripheral flow path 35. Flow into.

The exhaust gas G that has flowed into the outer peripheral flow path 35 through the guide portion 32 flows along the outer peripheral surface 20a of the inner case 20 toward the upstream end surface 14b of the GPF 14 (see FIG. 7). At this time, the exhaust gas G flowing through the outer peripheral flow path 35 heats the TWC 12 from the outer circumference through the inner case 20. By guiding the exhaust gas G to the outer peripheral flow path 35 in this way, the temperature of the TWC 12 can be raised in a short time immediately after the engine is started, so that the TWC 12 can be activated. In particular, since the temperature of the TWC 12 is likely to rise and the downstream portion in the first direction (downstream end face 12c side) can be heated from the outer circumference, the time for activating the TWC 12 can be shortened.

The TWC 12 is provided in the case 30 and is housed in the inner case 20 facing the inlet side tubular portion 31 with the outer peripheral flow path 35 interposed therebetween throughout the first direction P. By providing the TWC 12 in the inner case 20 as a whole in this way, the exhaust gas G flowing through the outer peripheral flow path 35 heats the TWC 12 from the outer periphery without entering the TWC 12. As a result, the heat retaining effect of TWC12 can be obtained, and the purification performance of the catalyst can be enhanced. Further, the double pipe structure composed of the case 30 and the inner case 20 effectively prevents heat from escaping to the outside of the case 30, and the inner case 20 covers the TWC 12 to form the outer peripheral flow path 35. Since the flowing exhaust gas G does not enter the TWC 12, there is also an effect that the flow path resistance of the exhaust gas G from the outer peripheral flow path 35 to the GPF 14 can be reduced. Further, since the exhaust gas G flowing through the outer peripheral flow path 35 does not enter the TWC 12, it is possible to prevent the exhaust gas G flowing in the first direction P from being obstructed in the TWC 12. Further, since the TWC 12 is provided in the inner case 20 as a whole, the exhaust gas G flowing into the TWC 12 passes through the entire area of the TWC 12, so that the exhaust gas G can be further purified. As a result, the total length of the TWC 12 can be shortened.

As described above, the exhaust gas G that has passed through the outer peripheral flow path 35 is the branch portion 33 in the space 16 between the outer peripheral surface 20a of the inner case 20 and the upstream end surface 14b of the GPF 14 in the inlet side tubular portion 31. It merges with the flow directly toward the upstream end surface 14b of the GPF 14 branched by, and flows into the GPF 14.

Exhaust gas G flowing into the GPF 14 is discharged to the exhaust pipe through the outlet side cylinder 38 after the fine particulate matter is removed.

Next, the exhaust gas treatment device 10'according to the modified example will be described with reference to FIGS. 8 to 11. FIG. 8 is a front view of the exhaust gas treatment device 10'. FIG. 9 is a cross-sectional view taken along the line IX-IX in FIG. FIG. 10 is a side view of the exhaust gas treatment device 10', and FIG. 11 is a cross-sectional view taken along the line XI-XI in FIG.

The modified example shown in FIGS. 8 to 11 has a configuration in which the GPF 14'is formed into a cylindrical shape. In this modification, as shown in FIGS. 9 and 10, the lengths of the GPF 14'and the intermediate cylinder portion 37'in the axial direction (first direction P) of the TWC 12 are shortened, so that the exhaust gas treatment device 10 is correspondingly shortened. 'Can be miniaturized. As described above, if the flow path cross-sectional area of the GPF 14'can be secured even if the GPF 14'is formed into a cylindrical shape, the exhaust gas treatment device 10'can be miniaturized by such a configuration.

Next, the exhaust gas treatment device 110 according to another modification will be described with reference to FIG. FIG. 12 is a cross-sectional view of a side surface of the exhaust gas treatment device 10 according to another modification.

A modification shown in FIG. 12 is an exhaust gas treatment device 110 in which the angle formed by the first direction P and the second direction Q is an acute angle. In the modified example shown in FIG. 12, the GPF 14 and the intermediate cylinder portion 37 can be arranged on the center side of the TWC 12 in the axial direction (first direction P) of the TWC 12. As a result, the length of the TWC 12 in the axial direction (first direction P) is shortened, so that the exhaust gas treatment device 10 can be miniaturized accordingly.

Next, the detailed mounting position of the air-fuel ratio sensor 40 will be described with reference to FIGS. 13 and 14.

In the exhaust gas treatment device 10 of the present embodiment, the air-fuel ratio sensor 40 attached to the case 30 is on the flow path between the TWC 12 and the GPF 14, and the exhaust gas G is formed along the shape of the inner wall surface 31c of the case 30. A region having a high flow velocity is formed, and the measuring unit 41 of the air-fuel ratio sensor 40 is located at a position where the flow velocity of the exhaust gas G is faster than the others.

Here, a more specific mounting position of the air-fuel ratio sensor 40 will be described with reference to FIG. FIG. 13 shows the result of simulating the flow of the exhaust gas G from the TWC 12 to the GPF 14 of the exhaust gas treatment device 10. FIG. 13 shows the distribution of the flow velocity. Further, FIG. 14 is a list of the results of simulating the flow of the exhaust gas G from the TWC 12 to the GPF 14 with and without the branch portion 33 in each of the exhaust gas treatment devices 10, 10'and 110.

The dark-colored portion in the portion (region A) surrounded by the thick line in FIG. 13 and the white portion around the dark-colored portion are portions where the flow velocity is particularly high. The region A as the second region extends along the tangential direction D of the top portion 33a which is downstream from the branch portion 33 and most protrudes in the first direction P of the branch portion 33.

Therefore, in the exhaust gas treatment device 10, the measurement unit 41 of the air-fuel ratio sensor 40 is attached to the inlet side cylinder portion 31 so as to be located in the region A. As a result, the air-fuel ratio sensor 40 can measure the oxygen concentration of the exhaust gas G that has passed through the TWC 12 with high accuracy. Such an air-fuel ratio sensor 40 may be inserted and fixed at any angle with respect to the case 30 as long as the above-mentioned measuring unit 41 is located in the region A. The air-fuel ratio sensor 40 may be arranged at an angle toward the TWC 12 or at an angle toward the GPF 14. However, it is preferable that the air-fuel ratio sensor 40 is arranged along the flow direction of the exhaust gas G, and the measuring unit 41 is arranged toward the lower side in the gravity direction so that water droplets or the like do not adhere to the measuring unit 41. Is preferable. In the configuration shown in FIG. 5 or the like, when the second direction Q is the top-bottom direction, it is preferable to arrange the measuring unit 41 toward the GPF 14.

In addition, when there is a space limitation or a space for providing the flat surface portion 31d for attaching the air-fuel ratio sensor 40 to the inlet side cylinder portion 31 cannot be secured (for example, near the joint portion 31e formed when the inlet side cylinder portion 31 is manufactured). Or, in the case of the vicinity of the curved surface portion of the inlet side cylinder portion 31), the air-fuel ratio sensor is located in the region A1 (the region shown by the thick dotted line in FIGS. 13 and 14) as the first region where the flow velocity of the exhaust gas G is relatively high. The air-fuel ratio sensor 40 may be attached to the inlet-side tubular portion 31 so that the measuring portion 41 of the 40 is located. That is, it is preferable that the measuring unit 41 of the air-fuel ratio sensor 40 is arranged in a region where the flow velocity of the exhaust gas G is high, excluding the region between the TWC 12 and the GPF 14 where the flow velocity of the exhaust gas G is the slowest. .. However, the present invention is not limited to this, and for example, in consideration of restrictions such as the fixed position of the main body portion of the air-fuel ratio sensor 40 and the mounting space, a region where the sensor sensitivity can be ensured (for example, a region having the highest flow velocity). It is also possible to arrange the measuring unit 41 of the air-fuel ratio sensor 40 in a nearby peripheral area or the like).

The region A1 is a region surrounded by the downstream end surface 12c of the TWC 12, the upstream end surface 14b of the GPF 14, and the inner wall surface 31c of the inlet side tubular portion 31 that receives the exhaust gas G that has passed through the TWC 12. It is set closer to GPF14 than the center. The center of the TWC 12 refers to a plane region including the center line O of the TWC 12 in the third direction R. In the region A1, the flow rate of the exhaust gas G from the TWC 12 to the GPF 14 constitutes the mainstream, so that the flow velocity of the exhaust gas G becomes relatively high. Therefore, by attaching the air-fuel ratio sensor 40 to the inlet side cylinder 31 so that the measuring unit 41 is located in the region A1, the oxygen concentration of the exhaust gas G that has passed through the TWC 12 can be accurately measured. In the present embodiment, the region A1 referred to here is the case 30 facing the downstream end surface 12c of the TWC 12, the upstream end surface 14b of the GPF 14, and the inner wall surface 31c (the downstream end surface 12c of the TWC 12) that receives the exhaust gas G. The exhaust gas G that has passed through the TWC 12 is a flow path (space) of the exhaust gas G that is substantially surrounded by the inner wall surface of the TWC 12 and flows toward the GPF 14 side. This is a flow path extending from the space sandwiched between the lower end surface on the GPF 14 side and the inner wall surface 31c of the case 30 to the upstream end surface 14b side of the GPF 14 along the surface direction of the downstream end surface 12c of the TWC 12. Further, the inner wall surface 31c of the case 30 is a wall surface facing the downstream end surface 12c of the TWC 12, and may include a wall surface extending until reaching the GPF 14 side. The wall surface may be, for example, only a flat surface. It may be composed of a flat surface and a deformed surface.

Further, since it is easy to form a boss at a position avoiding the joint portion 31e, the air-fuel ratio sensor 40 may be attached to such a position.

A more specific mounting position of the air-fuel ratio sensor 40 will be described with reference to FIGS. 15A and 15B.

15A and 15B are the results of simulating the flow of the exhaust gas G in the cross section along the XV-XV line of FIG. Note that Case 1, Case 2, and Case 3 in FIGS. 15A and 15B are the results of simulating the engine rotation speeds of low rotation speed, medium rotation speed, and high rotation speed in this order. Further, FIG. 15A shows a case where the air-fuel ratio sensor 40 is attached at the position shown in FIG. 4, and FIG. 15B shows the case where the air-fuel ratio sensor 40 is located on the opposite side of the joint portion 31e from the position shown in FIG. It is a simulation result when it is attached.

As is clear from FIGS. 15A and 15B, there is a region where the flow velocity of the exhaust gas G is relatively high, that is, a region A1 even if the inlet side cylinder portion 31 deviates from the central position in the third direction R. Therefore, for example, even if the air-fuel ratio sensor 40 cannot be attached to the center of the inlet side tubular portion 31 in the third direction R due to the presence of the joint portion 31e or the like, the measuring unit 41 is located in the region A1. By attaching the air-fuel ratio sensor 40 to the inlet side cylinder portion 31, the oxygen concentration of the exhaust gas G that has passed through the TWC 12 can be measured with high accuracy.

According to the above first embodiment, the following effects are obtained.

In the exhaust gas treatment device 10 of the present embodiment, in order to improve the purification performance of the exhaust gas G, two catalysts (specifically, TWC12 and GPF14) are arranged so as to overlap each other to reduce the size, and further, the TWC12. The mainstream speed (flow velocity) of the exhaust gas G flowing toward the GPF 14 side is increased while the exhaust gas G passing through the case 30 collides with the inner wall surface of the case 30, and the region A in which the flow velocity of the exhaust gas G between the TWC 12 and the GPF 14 is high. Alternatively, since the air-fuel ratio sensor 40 is installed so that the measurement unit 41 of the air-fuel ratio sensor 40 is located in the area A1, the air-fuel ratio sensor 40 that measures the exhaust gas G is compact and excellent in that it can detect a numerical value with high accuracy. It is possible to realize an exhaust gas treatment device having an exhaust gas purification performance.

Further, in the exhaust gas treatment device 10, when the TWC 12 and the GPF 14 are viewed from the directions orthogonal to the first direction P and the second direction Q, both ends of the TWC 12 in the first direction P are the GPF 14 in the first direction P. It is located between both ends of. As a result, the TWC 12 does not protrude from the GPF 14 to the outside of the first direction P, so that the exhaust gas treatment device 10 can be miniaturized. Further, when a heater (or a catalyst with a heater) is provided on the upstream side of the first direction P of the TWC 12, the amount of protrusion of the heater (or a catalyst with a heater) in the first direction P can be reduced. it can. That is, in the present embodiment, the exhaust gas treatment device 10 may be further provided with a heater for heating the exhaust gas G on the upstream side of the TWC 12, and according to such a configuration, the TWC 12 is heated using the exhaust gas G as a medium. This makes it possible to use an exhaust gas treatment device that exhibits excellent exhaust gas purification performance in situations such as when the engine is started. By arranging the TWC 12 so as to overlap the GPF 14 in the first direction P, it is possible to realize an exhaust gas treatment device that is small as a whole and has excellent exhaust gas purification performance even if the TWC 12 is configured to slightly protrude from the GPF 14. ..

(Second Embodiment)
The exhaust gas treatment device 210 according to the second embodiment of the present invention will be described with reference to FIG. FIG. 16 is a cross-sectional view of a side surface of the exhaust gas treatment device 210, which corresponds to a cross section taken along the line VV in FIG. Hereinafter, the points different from those of the first embodiment will be mainly described, and the same components as those of the exhaust gas treatment device 10 of the first embodiment are designated by the same reference numerals and the description thereof will be omitted. In FIG. 16, the inlet side flange 11, the diffuser portion 25, and the outlet side tubular portion 38 are not shown.

The second embodiment is different from the first embodiment in that it includes an EHC (electric heating catalyst) 250. Specifically, the exhaust gas treatment device 210 further includes an EHC 250 for purifying the exhaust gas G on the upstream side of the TWC 212 for purifying the exhaust gas G. Further, in the exhaust gas treatment device 210, a flat surface portion 231d is provided in the vicinity of the branch portion 233, and the air-fuel ratio sensor 40 is attached to the flat surface portion 231d. As a result, it is possible to effectively prevent water droplets and the like from adhering to the measuring unit 41 of the air-fuel ratio sensor 40 in the case 30.

The EHC 250 includes a heater portion 251 having electrodes 252a and 252b, and an electrode support 253 made of a honeycomb structure that supports the heater portion 251 and the electrodes 252a and 252b.

The heater unit 251 is, for example, a spiral heater that generates heat by the current applied to the electrodes 252a and 252b. The heater portion 251 is held in the extension cylinder portion 236 by welding the electrodes 252a and 252b to the extension cylinder portion 236 fixed to the outer peripheral surface 20a of the inner case 20 by welding.

The electrode support 253 is held in the inner case 20 so that its outer peripheral surface 253a is located on the upstream side of the TWC 12 via the cushioning material 215.

Between the heater unit 251 and the electrode support 253, a plurality of pins 254 for maintaining the distance between the heater unit 251 and the electrode support 253 and holding the heater unit 251 and the electrodes 252a and 252b are provided. .. The plurality of pins 254 are provided between the heater portion 251 and the electrode support 253 so as to be inserted into each of the heater portion 251 and the electrode support 253.

In the exhaust gas treatment device 210, the temperature of the exhaust gas G flowing in the extension cylinder portion 236 is reached by passing an electric current through the electrodes 252a and 252b to the heater portion 251 at the time of cold start (at the time of cold start) at the time of starting the engine. Is heated to 200 ° C. to 300 ° C., and the TWC212 is heated by the heated exhaust gas G. As a result, the catalyst component of TWC212 can be brought to the activation temperature in a short time. As described above, in the exhaust gas treatment device 210, the catalyst component of the TWC 212 can be activated in a short time, so that the purification performance at the time of starting the engine can be improved.

As shown in FIG. 16, in the exhaust gas treatment device 210, when the TWC 212 and the GPF 14 are viewed from the third direction R, both ends of the TWC 212 in the first direction P are between both ends of the GPF 14 in the first direction P. It is formed so as to be located in. As a result, even when the space for providing the exhaust gas treatment device 210 is limited, the space for providing the EHC 250 can be secured. In other words, by adopting the above configuration, it is possible to suppress an increase in the size of the exhaust gas treatment device 210.

In the above embodiment, the configuration in which one heater unit 251 is provided has been described as an example, but in the exhaust gas treatment device 210, a plurality of heater units 251 may be provided.

According to the above second embodiment, the following effects are obtained.

Since the exhaust gas treatment device 210 includes the EHC 250, the catalyst component of the TWC 212 can be activated in a short time. As a result, the purification performance at the time of starting the engine can be improved.

The exhaust gas treatment device 210 is formed so that both ends of the TWC 212 in the first direction P are located between both ends of the GPF 14 in the first direction P when the TWC 212 and the GPF 14 are viewed from the third direction R. .. As a result, even when the space for providing the exhaust gas treatment device 210 is limited, the space for providing the EHC 250 can be secured. If there is a space limitation for installing the exhaust gas treatment device 210, the EHC 250 may not be provided. For example, a metal layer may be provided on the outer peripheral surface of the TWC 212 or GPF 14, and the TWC 212 or GPF 14 may be directly heated by energization from the outside. As a result, activation of the catalyst component can be realized in a short time by heating the TWC212 or GPF14 while omitting the space for providing the EHC250. In such a case, the TWC212 or GPF14 may be made of, for example, a honeycomb carrier having conductivity, and the material thereof may be made of metal or ceramics as long as the conductivity is imparted (current path is formed).

The configuration, operation, and effect of the embodiment of the present invention configured as described above will be collectively described.

The exhaust gas treatment devices 10, 10', 110, 210 have a first catalyst carrier (TWC12) that purifies the exhaust gas G flowing along the first direction P, and an exhaust gas G that has passed through the first catalyst carrier (TWC12). The second catalyst carrier (GPF14) that purifies the exhaust gas G flowing along the second direction Q that intersects the first direction P, the first catalyst carrier (TWC12), and the second catalyst carrier (GPF14) are used. It includes a case 30 for accommodating, and a sensor (air fuel ratio sensor 40) for measuring the exhaust gas G that has passed through the first catalyst carrier (TWC12) and has a measuring unit 41 for measuring the exhaust gas G. The measuring unit 41 included in the sensor (air fuel ratio sensor 40) includes a downstream end surface 12c of the first catalyst carrier (TWC12), an upstream end surface 14b of the second catalyst carrier (GPF14), and the first catalyst carrier (TWC12) in the case 30. It is a region surrounded by the inner wall surface 31c that receives the exhaust gas G that has passed through the above, and is arranged in a region (region A1) closer to the second catalyst carrier (GPF14) than the center of the first catalyst carrier (TWC12).

According to this configuration, it is a region surrounded by the downstream end surface 12c of the first catalyst carrier (TWC12), the upstream end surface 14b of the second catalyst carrier (GPF14), and the inner wall surface 31c of the case 30, and is the first catalyst carrier. The measurement unit 41 of the sensor (air fuel ratio sensor 40) is located in the region (region A1) on the second catalyst carrier (GPF14) side of the center of (TWC12). In this region (region A1), the flow velocity of the exhaust gas G becomes relatively high because it constitutes the mainstream of the flow of the exhaust gas G from the first catalyst carrier (TWC12) to the second catalyst carrier (GPF14). Therefore, a sensor (air-fuel ratio) that measures the exhaust gas G when the flow direction of the exhaust gas G flowing through the first catalyst carrier (TWC12) and the flow direction of the exhaust gas G flowing through the second catalyst carrier (GPF14) intersect. Highly accurate numerical value can be detected by the sensor 40). Therefore, it is possible to provide small exhaust gas treatment devices 10, 10', 110, 210 capable of measuring the exhaust gas component with high accuracy while mounting a plurality of catalysts.

Further, even when the inflow condition of the exhaust gas G flowing into the exhaust gas treatment device 10 changes depending on, for example, the number of cylinders of the engine, the configuration such as mounting the turbocharger, the driving state of the engine, etc., the above-mentioned first catalyst carrier ( The exhaust gas G that has passed through the TWC12) flows toward the second catalyst carrier (GPF14) side while colliding with the inner wall surface 31c of the case 30. ) Is configured, the exhaust gas G can be measured with high accuracy and stability by the sensor (air fuel ratio sensor 40). That is, it is possible to realize an exhaust gas treatment device 10 that can adapt to various engine specifications and changes in engine drive conditions.

Further, the case 30 has a branching portion 33 that branches the exhaust gas G that has passed through the first catalyst carrier (TWC12) so as to guide a part of the exhaust gas G to the second catalyst carrier (GPF14), and the measuring unit 41 has a branching portion 33. , It is arranged in a region (region A) where the flow velocity of the exhaust gas G branched by the branching portion 33 and guided to the second catalyst carrier (GPF14) becomes high.

Further, the case 30 is provided on the inner wall surface 31c and has a branch portion 33 for branching a part of the exhaust gas G that has passed through the first catalyst carrier (TWC12) so as to be guided to the second catalyst carrier (GPF14). The measuring unit 41 is a region (GPF14) in which the exhaust gas G flows toward the second catalyst carrier (GPF14), which is the tangential direction D of the top portion 33a of the branching portion 33 that protrudes most in the first direction P and is branched by the branching portion 33. It is arranged in the area A).

In these configurations, a part of the exhaust gas G that has passed through the first catalyst carrier (TWC12) collides with the branch portion 33 formed on the inner wall surface 31c of the case 30, and the tangential direction D of the top portion 33a of the branch portion 33 D. It turns to and flows to the second catalyst carrier (GPF14). In the region (region A) where the exhaust gas G flowing toward the second catalyst carrier (GPF14) flows, the exhaust gas G that collides with the branch portion 33 and changes direction is guided, so that the flow velocity of the exhaust gas G is also in the region A1. Is high. Therefore, by installing the sensor (air-fuel ratio sensor 40) in the region A, the sensor for measuring the exhaust gas G (air-fuel ratio sensor 40) can detect the numerical value with high accuracy. In the above-described embodiment, the configuration in which the branch portion 33 is provided in the case 30 has been described as described above, but without providing such a branch portion 33, for example, the shape of the inner wall surface 31c of the case 30 is used. 2 Only the flow velocity of the exhaust gas G flowing to the catalyst carrier (GPF14) side may be adjusted.

Further, the main body portion of the sensor (air-fuel ratio sensor 40) is attached to the flat surface portion 31d provided on the case 30 from the outside of the case 30.

According to this configuration, since it is easier to form a boss on the flat surface portion 31d provided on the case 30 than on the curved surface portion, a boss for attaching the sensor (air-fuel ratio sensor 40) can be easily formed.

Further, the case 30 has a joint portion 31e formed by abutting and joining plate-shaped members, and the sensor (air-fuel ratio sensor 40) is attached at a position avoiding the joint portion 31e.

According to this configuration, it is difficult to form a boss at the joint portion 31e of the plate-shaped member. Therefore, by avoiding the joint portion 31e, a boss for attaching the sensor (air-fuel ratio sensor 40) can be easily formed. Further, by arranging the sensor (air-fuel ratio sensor 40) in a portion of one of the plate-shaped members that divides the case 30 so as to avoid the joint portion 31e, the strength of the joint portion 31e can be ensured.

Further, when the first catalyst carrier (TWC12) and the second catalyst carrier (GPF14) are viewed from the directions orthogonal to the first direction P and the second direction Q, the first catalyst carrier (TWC12) in the first direction P ) Is located between both ends of the second catalyst carrier (GPF14) in the first direction P.

According to this configuration, since the first catalyst carrier (TWC12) does not protrude from the second catalyst carrier (GPF14) to the outside in the first direction P, the exhaust gas treatment device 10 can be miniaturized. Further, when the heater or the catalyst with the heater is provided on the upstream side of the first direction P of the first catalyst carrier (TWC12), the amount of protrusion of the heater or the catalyst with the heater in the first direction P is reduced. be able to.

Further, the case 30 is formed on the inner wall surface 31c and the tubular portion (inlet side tubular portion 31) forming the outer peripheral flow path 35 through which the exhaust gas G flows between the case 30 and the outer peripheral surface of the first catalyst carrier (TWC12). , A branch portion 33 that branches a part of the exhaust gas G that has passed through the first catalyst carrier (TWC12) so as to lead to the second catalyst carrier (GPF14), and the remaining exhaust gas G branched by the branch portion 33 are outer peripherals. It has a guide portion 32 that leads to the flow path 35.

According to this configuration, of the exhaust gas G branched by the branch portion 33, the remaining exhaust gas G that is not guided to the second catalyst carrier (GPF14) is guided to the outer peripheral flow path 35 and goes around the outer peripheral flow path 35. It flows in the direction toward the second catalyst carrier (GPF14). At this time, the exhaust gas G guided to the outer peripheral flow path 35 heats the first catalyst carrier (TWC12) from the outer circumference. Therefore, immediately after starting the engine, the temperature of the first catalyst carrier (TWC12) can be raised in a short time to activate the first catalyst carrier (TWC12). In particular, the time for activating the entire first catalyst carrier (TWC12) can be shortened by heating the portion downstream of the first direction P, where the temperature of the first catalyst carrier (TWC12) is likely to rise, from the outer circumference. it can.

Further, the guide portion 32 has an inclined portion 32a that is inclined at a predetermined angle θ from the branch portion 33 to the downstream side in the first direction P with respect to the plane X orthogonal to the first direction P.

According to this configuration, the guide portion 32 has an inclined portion 32a that is inclined to the downstream side in the first direction P from the branch portion 33. By providing the inclined portion 32a, the exhaust gas G branched by the branch portion 33 can be gently changed in direction and guided to the outer peripheral flow path 35 along the inner wall surface 31c of the case 30. Therefore, the exhaust gas G can be guided to the outer peripheral flow path 35 without obstructing the flow of the exhaust gas G passing through the first catalyst carrier (TWC12) and toward the branch portion 33.

Further, the case 30 has a tubular portion (inlet side tubular portion 31) that forms an outer peripheral flow path 35 through which the exhaust gas G flows between the case 30 and the outer peripheral surface 12a of the first catalyst carrier (TWC12), and the first catalyst. The carrier (TWC12) is provided in the case 30 and is housed in the inner case 20 facing the tubular portion (inlet side tubular portion 31) with the outer peripheral flow path 35 interposed therebetween over the entire first direction P.

According to this configuration, by providing the inner case 20, the exhaust gas G flowing through the outer peripheral flow path 35 does not enter the first catalyst carrier (TWC12) and moves the first catalyst carrier (TWC12) from the outer periphery. Heat. Therefore, the flow path resistance of the exhaust gas G from the outer peripheral flow path 35 to the second catalyst carrier (GPF14) can be reduced. Further, since the exhaust gas G flowing through the outer peripheral flow path 35 does not enter the first catalyst carrier (TWC12), the flow of the exhaust gas G flowing in the first direction P in the first catalyst carrier (TWC12) is obstructed. Is prevented. In the above-described embodiment, a double-tube structure in which the first catalyst carrier (TWC12) covered with the inner case 20 is arranged in the case 30 is adopted, but the present invention is of course not limited to this, and for example, the present invention is not limited to this. Two catalysts may be arranged as they are in one case. That is, the first catalyst and the second catalyst are laid out in one case, only the flow path for guiding the exhaust gas G passing through the first catalyst to the second catalyst is provided, and the flow path is formed and from the first catalyst. By forming the wall surface of the case that receives the outflowing exhaust gas G partially away from the first catalyst (the shape of the case 30 shown in FIG. 16), a region having a high flow velocity is created in the flow path of the exhaust gas G. The present invention also includes a configuration in which a detection point (contact point between exhaust gas and G) of the sensor (air fuel ratio sensor 40) is provided in the region.

Although the embodiments of the present invention have been described above, the above embodiments are only a part of the application examples of the present invention, and the technical scope of the present invention is limited to the specific configurations of the above embodiments. Absent.

In the above embodiment, the air-fuel ratio sensor 40 has been described as an example of the sensor, but another sensor for measuring the numerical value of the exhaust gas G may be applied as the sensor.

The position where the flat surface portion 231d is provided may be any position as long as the measurement unit 41 is located in the area A1 or the area A when the air-fuel ratio sensor 40 is attached.

10,10', 110,210 Exhaust gas treatment device 12,212 TWC (first catalyst carrier)
12a Outer peripheral surface 12c Downstream end surface 14 GPF (second catalyst carrier)
14a Outer peripheral surface 14b Upstream side end surface 20 Inner case 20a Outer peripheral surface 30 Case 31 Entrance side tubular part (cylindrical part)
31c Inner wall surface 31d, 231d Flat surface 31e Joint 32 Guide 32a Inclined 33 Branch 33a Top 35 Outer flow path 40 Air-fuel ratio sensor (sensor)
41 Measuring unit R area (second area)
R1 area (first area)

Claims (15)

Exhaust gas treatment device
A first catalyst carrier that purifies the exhaust gas flowing along the first direction,
An electric heating catalyst arranged on the upstream side of the first catalyst carrier and having a heater for heating the exhaust gas, and
A second catalyst carrier that purifies the exhaust gas that has passed through the first catalyst carrier and flows along the second direction that intersects the first direction.
A case containing the first catalyst carrier and the second catalyst carrier, and
A sensor that has a measuring unit for measuring exhaust gas and measures the exhaust gas that has passed through the first catalyst carrier, and
An outer peripheral flow path provided between the outer peripheral surface of the first catalyst carrier and the inner peripheral surface of the case and covering the outer periphery of the first catalyst carrier, and
The case is formed so as to project inward, and includes a branch portion for branching the exhaust gas that has passed through the first catalyst carrier so as to guide the exhaust gas to the second catalyst carrier and the outer peripheral flow path.
The measuring unit included in the sensor is surrounded by a downstream end surface of the first catalyst carrier, an upstream end surface of the second catalyst carrier, and an inner wall surface that receives exhaust gas that has passed through the first catalyst carrier in the case. It is a region and is arranged in a region on the side of the second catalyst carrier rather than the center of the first catalyst carrier.
The measuring unit is arranged in a region where exhaust gas flows from the branching unit toward the second catalyst carrier.
The angle formed by the top of the branch is 70 ° to 120 °.
An exhaust gas treatment device characterized by the fact that. Exhaust gas treatment device
A first catalyst carrier that purifies the exhaust gas flowing along the first direction,
A heater arranged on the upstream side of the first catalyst carrier and heating the exhaust gas,
A second catalyst carrier that purifies the exhaust gas that has passed through the first catalyst carrier and flows along the second direction that intersects the first direction.
A case containing the first catalyst carrier and the second catalyst carrier, and
A sensor that has a measuring unit for measuring exhaust gas and measures the exhaust gas that has passed through the first catalyst carrier, and
An outer peripheral flow path provided between the outer peripheral surface of the first catalyst carrier and the inner peripheral surface of the case and covering the outer periphery of the first catalyst carrier, and
A branch portion in which the case is formed so as to project inward and the exhaust gas that has passed through the first catalyst carrier is branched so as to be guided to each of the second catalyst carrier and the outer peripheral flow path.
With
The measuring unit included in the sensor is surrounded by a downstream end surface of the first catalyst carrier, an upstream end surface of the second catalyst carrier, and an inner wall surface that receives exhaust gas that has passed through the first catalyst carrier in the case. It is a region and is arranged in a region on the side of the second catalyst carrier rather than the center of the first catalyst carrier.
The measuring unit is arranged in a region where exhaust gas flows from the branching unit toward the second catalyst carrier.
The angle formed by the top of the bifurcation is 70 ° to 120 °.
An exhaust gas treatment device characterized by the fact that. Exhaust gas treatment device
A first catalyst carrier that purifies the exhaust gas flowing along the first direction,
A second catalyst carrier that purifies the exhaust gas that has passed through the first catalyst carrier and flows along the second direction that intersects the first direction.
A case containing the first catalyst carrier and the second catalyst carrier, and
A sensor that has a measuring unit for measuring exhaust gas and measures the exhaust gas that has passed through the first catalyst carrier, and
An outer peripheral flow path provided between the outer peripheral surface of the first catalyst carrier and the inner peripheral surface of the case and covering the outer periphery of the first catalyst carrier, and
The case is formed so as to project inward, and includes a branch portion for branching the exhaust gas that has passed through the first catalyst carrier so as to guide the exhaust gas to each of the second catalyst carrier and the outer peripheral flow path.
The first catalyst carrier has a metal layer provided on the outer peripheral surface and capable of heating the first catalyst carrier by being energized.
The measuring unit included in the sensor is surrounded by a downstream end surface of the first catalyst carrier, an upstream end surface of the second catalyst carrier, and an inner wall surface that receives exhaust gas that has passed through the first catalyst carrier in the case. It is a region and is arranged in a region on the side of the second catalyst carrier rather than the center of the first catalyst carrier.
The measuring unit is arranged in a region where exhaust gas flows from the branching unit toward the second catalyst carrier.
The angle formed by the top of the branch is 70 ° to 120 °.
An exhaust gas treatment device characterized by the fact that. The exhaust gas treatment apparatus according to any one of claims 1 to 3.
The second catalyst carrier is arranged below the first catalyst carrier in the direction of gravity.
An exhaust gas treatment device characterized by the fact that. The exhaust gas treatment apparatus according to any one of claims 1 to 4.
The measuring unit is arranged so as to face downward in the direction of gravity.
An exhaust gas treatment device characterized by the fact that. The exhaust gas treatment apparatus according to any one of claims 1 to 5.
The measuring unit is arranged in a region of the branching portion that is tangential to the top of the branching portion and projects in the first direction, is branched by the branching portion, and exhaust gas flows toward the second catalyst carrier.
An exhaust gas treatment device characterized by the fact that. The exhaust gas treatment apparatus according to any one of claims 1 to 6.
The main body portion of the sensor is attached to a flat surface portion provided on the case from the outside of the case.
An exhaust gas treatment device characterized by the fact that. The exhaust gas treatment apparatus according to any one of claims 1 to 7.
The case has a joint portion formed by abutting and joining plate-shaped members.
The sensor is mounted in a position avoiding the joint.
An exhaust gas treatment device characterized by the fact that. The exhaust gas treatment apparatus according to any one of claims 1 to 8.
When the first catalyst carrier and the second catalyst carrier are viewed from the directions orthogonal to the first direction and the second direction, both ends of the first catalyst carrier in the first direction are the first. Located between both ends of the second catalyst carrier in the direction,
An exhaust gas treatment device characterized by the fact that. The exhaust gas treatment apparatus according to any one of claims 1 to 9.
The case is
The tubular portion forming the outer peripheral flow path and
A guide portion that guides the exhaust gas branched by the branch portion to the outer peripheral flow path, and a guide portion.
Have,
An exhaust gas treatment device characterized by the fact that. The exhaust gas treatment apparatus according to claim 10.
The guide portion has an inclined portion that is inclined at a predetermined angle from the branch portion to the downstream side in the first direction with respect to a plane orthogonal to the first direction.
An exhaust gas treatment device characterized by the fact that. The exhaust gas treatment apparatus according to any one of claims 1 to 11.
The case has a tubular portion that forms the outer peripheral flow path.
The first catalyst carrier is provided in the case and is housed in the inner case facing the tubular portion across the outer peripheral flow path over the entire area in the first direction.
An exhaust gas treatment device characterized by the fact that. The exhaust gas treatment apparatus according to any one of claims 1 to 12.
The sensor is arranged so that the measuring unit faces the downstream side in the gas flow direction.
An exhaust gas treatment device characterized by the fact that. The exhaust gas treatment apparatus according to any one of claims 1 to 13.
The main body portion of the sensor is attached to a recess provided outside the case by forming the branch portion.
An exhaust gas treatment device characterized by the fact that. The exhaust gas treatment apparatus according to any one of claims 1 to 14.
The outer peripheral flow path covers the entire circumference of the first catalyst carrier.
An exhaust gas treatment device characterized by the fact that.

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