JPWO2015151282A1 - Exhaust gas purification device - Google Patents

Abstract

An exhaust gas purification device disposed in an exhaust passage of an internal combustion engine, wherein a case in which exhaust gas flows and a reducing agent that is provided in the case and consumes a reducing agent supplied in the case are reduced An exhaust gas purifying apparatus comprising a catalyst to be treated is disposed in a space between a reducing agent supply position and a catalyst disposition position in a case, and an exhaust gas flow path in the space. A flow path forming member is formed.

Description

  The present invention relates to an exhaust gas purification device that purifies exhaust gas discharged from an internal combustion engine.

As a device for purifying exhaust gas discharged from an internal combustion engine such as a gasoline engine or a diesel engine, a device for removing particulate matter (PM) in the exhaust gas or a nitrogen oxide (NO) in the exhaust gas Devices for reducing and removing _X ) are known.

  As an apparatus for removing PM, an apparatus including a diesel particulate filter (DPF) has been developed (for example, see Patent Document 1).

In addition, as an apparatus for reducing and removing NO _x , an apparatus having a selective catalytic reduction (SCR) that reduces NO _x has been developed (see, for example, Patent Document 2).

In recent years, exhaust gas regulations including exhaust gas purifiers having DPF for removing PM and SCR for reducing and removing NO _x have been proposed in accordance with stricter regulations on exhaust gas. For example, see Patent Document 3).

JP 2009-144672 A JP 2007-332797 A JP 2009-167806 A

By the way, in the exhaust gas purification apparatus provided with SCR, the liquid reducing agent is added to the exhaust gas to vaporize the liquid reducing agent, and the exhaust gas and the liquid reducing agent (vaporized reducing agent) are mixed. To reach the SCR. At this time, it is desired that the liquid reducing agent diffuses uniformly in the exhaust gas. This is because, when the liquid reducing agent does not diffuse uniformly in the exhaust gas, the reaction between the exhaust gas component and the liquid reducing agent becomes insufficient, and the decomposition efficiency of NO _x decreases.

  Therefore, in an exhaust gas purification apparatus equipped with an SCR, the distance from the liquid reducing agent injection port to the SCR is made as long as possible so that the liquid reducing agent and the exhaust gas are mixed more reliably and uniformly. It is considered.

  However, when trying to make the distance from the liquid reducing agent injection port to the SCR as long as possible, especially in an exhaust gas purifying apparatus equipped with both a DPF and an SCR, the length of the entire apparatus becomes long. May increase the size of the vehicle and make it difficult to mount it on a vehicle.

  For example, in Patent Document 3, a first cylindrical case in which a DPF is stored and a second cylindrical case in which an SCR is stored are arranged in parallel, and from one end of the first cylindrical case, By passing the connecting pipe obliquely to one end of the second cylindrical case, the distance from the liquid reducing agent injection port to the SCR is suppressed while suppressing the length of the entire apparatus from becoming long. A configuration that is as long as possible has been proposed. However, even with such a configuration, a long connecting pipe is still required, which hinders downsizing of the apparatus.

  For example, in Patent Document 2, a shielding plate is provided in the exhaust passage to generate a vortex, and the liquid reducing agent is injected into a portion where the vortex is generated so that the liquid reducing agent can be efficiently evaporated even at a short distance ( (Diffusion). However, in this case, it is necessary to provide the position of the liquid reducing agent injection port at the location where the vortex is generated. That is, it may be necessary to change the position of the injection port from the conventional one. In this case, not only the exhaust gas purification device but also the peripheral configuration for injecting the liquid reducing agent may require a design change.

  It is desirable to provide an exhaust gas purifying device that can achieve both higher vehicle mountability and reduction processing efficiency at a higher level.

  The present invention of one aspect is an exhaust gas purifying device disposed in an exhaust passage of an internal combustion engine, and includes a case into which exhaust gas flows, a reducing agent provided in the case, and supplied into the case. The present invention relates to an exhaust gas purifying apparatus including a catalyst that consumes and reduces exhaust gas. The exhaust gas purification apparatus of the present invention is disposed in a space in the case from the reducing agent supply position to the catalyst disposition position, and forms an exhaust gas flow path in the space. The flow path forming member is provided. The reducing agent may be a liquid reducing agent.

  According to this aspect of the present invention, exhaust gas (more specifically, a mixed gas containing exhaust gas and a reducing agent) is supplied from the supply position from the supply position of the reducing agent to the catalyst. Instead of flowing directly to the catalyst, it flows along the flow path formed by the flow path forming member and reaches the catalyst. In this case, as compared with the case where the flow path forming member is not provided, the time and path length from the reducing agent supply position to the catalyst can be further increased for the mixed gas containing the exhaust gas and the reducing agent. As a result, more time and path length for the reducing agent to diffuse into the exhaust gas are secured, and uniform diffusion and vaporization of the reducing agent can be further promoted.

  For this reason, in the exhaust gas purifying apparatus, for example, by making the case longer, the exhaust gas passage length (path length) is ensured without making the exhaust gas passage longer, and the reducing agent is uniformly diffused. Further, vaporization can be promoted, and as a result, the efficiency of the exhaust gas reduction treatment by the catalyst can be improved.

  More specifically, in the present invention of one aspect, the flow path forming member is configured to block a part of the path from the reducing agent supply position to the catalyst disposition position in the space. Also good.

  According to this, the flow length of the exhaust gas is increased by the amount that the flow of the exhaust gas is blocked at the blocked portion and reaches the downstream side after the exhaust gas flows to the non-blocked portion. be able to.

Moreover, in this invention of one situation, the flow-path formation member may be provided with the protrusion part for branching the flow of exhaust gas.
According to this, compared with the case where the flow of the exhaust gas is unidirectional, the mixing of the exhaust gas and the reducing agent can be further promoted when the flow of the exhaust gas branches. That is, the uniform diffusion and vaporization of the reducing agent is further promoted, and the efficiency of the exhaust gas reduction treatment by the catalyst can be improved.

Furthermore, in one aspect of the present invention, the flow path forming member may be configured to form a merging portion where the exhaust gas that has branched and flowed merges.
According to this, the exhaust gas branched and flowing is merged and mixed at the merge portion, and as a result, the mixing of the exhaust gas and the reducing agent can be further promoted. For this reason, the uniform diffusion and vaporization of the reducing agent is further promoted, and the efficiency of the exhaust gas reduction treatment by the catalyst can be improved as described above.

  Furthermore, the present invention of another aspect is an exhaust gas purifying apparatus, which is a case that accommodates a catalyst and a catalyst, and has an exhaust passage for discharging the exhaust gas that has flowed in after passing the catalyst. And a flow path forming member that divides an inflow space, which is formed on the upstream side of the catalyst inside the case and into which exhaust gas for allowing the catalyst to pass, into an upstream space and a downstream space. And comprising. The flow path forming member includes at least one opening that communicates the upstream space and the downstream space, and an opening that serves as a passage for exhaust gas flowing into the upstream space to flow to the downstream space; A guide surface is formed for guiding the exhaust gas flowing into the side space so as to change the flow direction and guiding the exhaust gas to the opening.

  According to this, the exhaust gas that has flowed into the upstream space in the inflow space is guided so as to change the flow direction and is guided to the opening, and reaches the downstream space (and thus the catalyst) from the opening. That is, the degree of freedom of the exhaust gas path from the flow into the inflow space to the catalyst is limited by the opening, and the exhaust gas is guided so as to change the flow direction in the process of being led to the opening. Therefore, the time until the exhaust gas reaches the catalyst and the path length can be increased. In addition, the diffusion of exhaust gas is promoted. Therefore, for example, when a mixed gas containing exhaust gas and a reducing agent flows into the inflow space, uniform diffusion and vaporization of the reducing agent can be promoted. The reducing agent may be one that reduces exhaust gas by reacting with a catalyst.

In another aspect of the present invention, the guide surface may be configured to guide exhaust gas that has flowed into the upstream space so as to be branched into a plurality and guide the exhaust gas to the opening.
The exhaust gas is branched into a plurality of parts and guided to the opening, thereby promoting the diffusion of the exhaust gas. Therefore, for example, when a mixed gas containing exhaust gas and a reducing agent flows into the inflow space, uniform diffusion and vaporization of the reducing agent can be promoted. Therefore, the efficiency of the exhaust gas reduction treatment by the catalyst can be improved.

In another aspect of the present invention, the guide surface may be configured to guide the branched exhaust gas to the same opening.
The exhaust gas flowing in a branched manner is guided to the same opening, so that the exhaust gas can be mixed in the opening. Thereby, for example, when a mixed gas containing exhaust gas and a reducing agent flows into the inflow space, mixing of the exhaust gas and the reducing agent can be further promoted. For example, uniform diffusion and vaporization of the reducing agent is promoted. Therefore, the efficiency of the exhaust gas reduction treatment by the catalyst can be improved.

Moreover, in this invention of another situation, the guide surface may be comprised so that the exhaust gas after branching may join from a different direction.
When the exhaust gas merges from different directions, the flows collide with each other at the merged portion, so that the mixing of the exhaust gas can be promoted more than when the exhaust gas merges from the same direction. Therefore, for example, when a mixed gas containing exhaust gas and a reducing agent flows into the inflow space, mixing of the exhaust gas and the reducing agent can be further promoted. Therefore, the efficiency of the exhaust gas reduction treatment by the catalyst can be improved.

Moreover, in this invention of another aspect, the groove | channel which continues toward the said opening part side from the side into which exhaust gas flows in may be formed in the guide surface.
Further, the guide surface may be formed with a hook-like portion that protrudes from the guide surface and continues in an elongated shape from the exhaust gas inflow side toward the opening side.

Further, both the groove and the hook-shaped portion may be formed on the guide surface.
According to this, the flow of the exhaust gas can be guided by the groove or the hook-shaped portion. In this case, the exhaust gas flowing into the upstream space can flow more smoothly to the downstream space.

  Moreover, the shape of the channel | path of a groove | channel and a bowl-shaped part may be suitably determined so that the flow of exhaust gas may form a desired pattern. Depending on the shape of the channel of the groove or the bowl-shaped part, it is possible to increase the time until the exhaust gas reaches the catalyst and the path length, and the uniform diffusion and vaporization of the reducing agent in the exhaust gas can be promoted.

In another aspect of the present invention, the flow path forming member may be formed such that a wall portion separating the upstream space and the downstream space is not located on the central axis of the catalyst.
The wall that separates the upstream space and the downstream space is located closer to the catalyst side as much as the upstream space is secured. That is, the downstream space is narrowed. Therefore, in the configuration in which the wall portion is located on the central axis of the catalyst, it is difficult to secure the downstream space on the central axis of the catalyst. On the other hand, according to the above configuration, the downstream space can be ensured to the maximum on the central axis of the catalyst, and the path through which the exhaust gas flows can be more reliably formed (secured).

Moreover, in this invention of another situation, downstream space may be formed so that it may become so wide that it is close to a catalyst.
According to this, as the exhaust gas approaches the catalyst, the size of the downstream space where the exhaust gas can flow becomes larger, and the exhaust gas can reach the catalyst more smoothly.

  In another aspect of the present invention, the flow path forming member protrudes from the inner edge of the annular plate portion to the side opposite to the catalyst side, the annular plate portion being arranged to face the outer peripheral portion of the catalyst inflow surface. And a cylindrical protrusion. The inflow space may be partitioned into an upstream space and a downstream space by the annular plate portion and the protrusion, and at least a part of the outer peripheral surface of the protrusion may function as a guide surface. The opening may be formed in at least one of the annular plate portion and the protruding portion.

  According to this, when the exhaust gas flows into the upstream space defined by the annular plate portion and the projecting portion, the exhaust gas hits the projecting portion and is guided along at least a part of the outer peripheral surface of the projecting portion (that is, the guide surface). To the opening. Thus, a path through which the exhaust gas flows is ensured, and the length of the path through which the exhaust gas flows can be further increased by partitioning the upstream space and the downstream space. Therefore, for example, when a mixed gas containing exhaust gas and a reducing agent flows into the inflow space, diffusion and vaporization of the reducing agent can be promoted. Moreover, such an excellent effect can be realized by a flow path forming member having a simple shape including an annular plate portion and a cylindrical protrusion.

In another aspect of the present invention, the protrusion may have a shape that gradually narrows toward the tip.
According to this, the downstream space can be widened toward the side closer to the catalyst. In this case, the exhaust gas can flow through a wider space as it approaches the catalyst. Thereby, it can be expected that the exhaust gas reaches the catalyst through the downstream space more smoothly. In addition, the bias of the exhaust gas flowing into the catalyst can be suppressed.

Moreover, in this invention of another situation, the annular plate part and the protrusion part may be integrally molded by the flow-path formation member.
This can be advantageous, for example, in terms of manufacturing costs. It is also advantageous in terms of strength. That is, it is possible to prevent a decrease in strength and ensure an appropriate strength.

  In another aspect of the present invention, the guide surface may be configured not to have a plane perpendicular to the inflow direction of the exhaust gas to the upstream space. Here, the flat surface is a flat surface to the last, and the curved surface and the linear protrusion are not included in the flat surface. The gist here is that the plane is perpendicular to the inflow direction and does not have a flat surface having a predetermined area.

  On the other hand, it is permissible for the guide surface to have a portion (linear protrusion) forming a line perpendicular to the inflow direction of the exhaust gas. For example, it is permissible within the scope of the present invention that the guide surface is a curved surface and only the top portion of the curved surface is perpendicular to the inflow direction of the exhaust gas.

  According to the configuration in which the guide surface does not have a plane perpendicular to the inflow direction of the exhaust gas to the upstream space, the flow of the exhaust gas flowing into the upstream space is unnecessarily obstructed by the guide surface. Can be avoided. That is, the exhaust gas can flow into the downstream space more smoothly.

In another aspect of the present invention, the guide surface may be a curved surface.
According to this, since the exhaust gas is guided along the curved surface, the exhaust gas can flow into the downstream space more smoothly.

  Further, at least one of the groove and the bowl-shaped portion may be formed on the surface of the annular plate portion (the surface of the annular plate portion opposite to the surface facing the outer peripheral portion of the catalyst inflow surface). good.

It is the schematic of the exhaust-gas purification apparatus of this embodiment. It is a partial explanatory view of the exhaust gas purification device of this embodiment. It is a partial explanatory view of an exhaust gas purifying device of Modification 1. It is a partial explanatory view of an exhaust gas purifying device of Modification 2. FIG. 10 is a partial explanatory diagram of an exhaust gas purifying apparatus according to Modification 3. FIG. 10 is a partial explanatory view of an exhaust gas purification device of a fourth modification. FIG. 10 is a partial explanatory view of an exhaust gas purifying apparatus according to Modification 5. FIG. 10 is a partial explanatory diagram of an exhaust gas purifying apparatus according to Modification 6. FIG. 10 is a partial explanatory view of an exhaust gas purifying apparatus according to Modification 7. It is a figure which shows the effect | action of the exhaust-gas purification apparatus of this embodiment. It is a figure which shows the effect of the exhaust gas purification apparatus of this embodiment. It is a figure which shows the flow-path formation member of a modification. It is a figure which shows the flow-path formation member of a modification. It is a figure which shows the flow-path formation member of a modification.

DESCRIPTION OF SYMBOLS 1 ... Exhaust gas purification device, 2 ... DPF part, 4 ... SCR part, 6 ... DOC, 8 ... DPF, 10 ... Case, 12 ... Inlet, 14 ...・ Communication path, 16 ... SCR, 18 ... SLP, 20 ... Case, 22 ... Inflow chamber, 23 ... End, 24 ... Inner peripheral surface, 26 ... Injection nozzle 28 ... exhaust pipe, 30 ... exhaust hole, 100, 120, 140, 160, 180, 200, 220 ... flow path forming member, 103, 123, 143, 203 ... projection, 108 , 128, 148, 188, 208, 228... Notches.

Embodiments of the present invention will be described below with reference to the drawings. In the present application, “path” and “flow path” have the same meaning, and “path length” and “flow path length” have the same meaning.
[Configuration of exhaust gas purification device]
An exhaust gas purification apparatus 1 shown in FIG. 1 is an apparatus for purifying exhaust gas disposed in an exhaust passage of exhaust gas discharged from an internal combustion engine such as a diesel engine mounted on a vehicle. In FIG. 1, the flow of exhaust gas in the exhaust gas purification device 1 (flow of exhaust gas from the inlet to the outlet of the exhaust gas purification device 1) is indicated by arrows. However, the flow indicated by the arrows is an example. In particular, the flow indicated by the broken-line arrow from the flow path forming member 100 described later toward the SCR 16 is an example, and other forms of flow are also conceivable.

  The exhaust gas purification apparatus 1 includes a DPF (Diesel Particulate Filter) unit 2 and an SCR (Selective Catalytic Reduction) unit 4.

The DPF unit 2 and the SCR unit 4 are connected via a communication path 14.
The exhaust gas discharged from the internal combustion engine first flows into the DPF unit 2 through the inlet 12 in the exhaust gas purification device 1. The particulate matter (PM) in the exhaust gas is captured and removed (burned) by the DPF unit 2. Thereafter, the exhaust gas flows into the SCR unit 4 through the communication path 14. In the SCR unit 4, nitrogen oxide (NO _x ) in the exhaust gas is decomposed into nitrogen (N ₂ ) and water (H ₂ O), which are harmless components.

  The DPF unit 2 includes a cylindrical (more specifically, cylindrical) case 10, a carrier 6 (hereinafter referred to as DOC 6) having an oxidation catalyst (Diesel Oxidation Catalyst: DOC), and a DPF 8. The DOC 6 and the DPF 8 are accommodated in the case 10, and the DOC 6 is disposed upstream of the DPF 8 in the exhaust passage.

  The DOC 6 oxidizes excess fuel in the exhaust gas. In addition, this surplus fuel is brought about by post injection (additional injection after a combustion process) in an internal combustion engine, for example. And the temperature in an exhaust passage can rise with the reaction heat of the oxidation reaction.

  The DPF 8 is a filter that captures PM in exhaust gas, and is formed of porous ceramic, and has a structure that is configured in a lattice shape with a large number of holes. As the hole, it is opened at the end face on the inlet side (upstream side) and closed at the end face on the outlet side (downstream side), and closed at the end face on the inlet side and opened at the end face on the outlet side. The holes are provided alternately.

  The exhaust gas flows into the DPF 8 from the hole opened at the end face on the inlet side of the DPF 8, passes through the boundary wall of the hole, and flows out from the hole opened at the end face on the outlet side (downstream side) to the downstream side. . When passing through the boundary wall, PM in the exhaust gas is captured and deposited in the DPF 8.

  In the DPF unit 2, the PM accumulation amount in the DPF 8 is detected by a sensor (not shown). The DPF 2 is configured so that the temperature in the exhaust passage rises when it is determined that the amount of accumulated PM is greater than or equal to a predetermined amount based on the detection value of the sensor, thereby burning the PM. Let it be removed.

  The SCR unit 4 includes a cylindrical case 20 (more specifically, a cylindrical shape), a carrier 16 (hereinafter referred to as SCR 16) including a selective catalytic reduction (SCR), an oxidation catalyst for surplus ammonia decomposition (SLP). ) Including the carrier 18 (hereinafter, SLP18). The SCR 16 and the SLP 18 are accommodated in the case 20, and the SCR 16 is disposed upstream of the SLP 18 in the exhaust passage.

Specifically, the selective reduction catalyst (SCR) specifically reduces NO _x contained in the exhaust gas with ammonia (NH ₃ ) generated by the decomposition of the liquid reducing agent described later, thereby reducing nitrogen (N ₂ ) and water ( It is a catalyst for decomposition into H ₂ O). Specifically, the surplus ammonia decomposition oxidation catalyst (SLP) is an oxidation catalyst for decomposing surplus ammonia that is not used in the SCR 16.

  An exhaust pipe 28 is disposed on the downstream side of the SCR unit 4. Many exhaust holes 30 are formed in the exhaust pipe 28. The exhaust gas that has passed through the SCR 16 and the SLP 18 flows into the exhaust pipe 28 through the exhaust hole 30 and is discharged from the exhaust pipe 28.

  An inflow chamber 22 is provided on the upstream side of the SCR unit 4 (upstream side of the SCR 16). Further, as will be described later, in the exhaust gas purification apparatus 1 of the present embodiment, the flow path forming member 100 is disposed in the inflow chamber 22.

The communication passage 14 is provided with an injection nozzle 26 for injecting the liquid reducing agent into the communication passage 14 (for example, in exhaust gas). As the liquid reducing agent, for example, urea water can be considered. The liquid reducing agent injected from the injection nozzle 26 diffuses and vaporizes in the exhaust gas, reacts with components in the exhaust gas, and is decomposed into ammonia (NH ₃ ) and the like.

[Configuration of flow path forming member]
With reference to FIG. 2A-2D, the exhaust gas purification apparatus 1 to which the flow-path formation member 100 as an example is applied is demonstrated.

  FIG. 2A is a diagram showing a part of the appearance of the SCR unit 4. 2B is a cross-sectional view taken along the line IIB-IIB in FIG. 2A. 2C is a cross-sectional view taken along the line IIC-IIC in FIG. 2A. FIG. 2D is a perspective view of the flow path forming member 100.

  The flow path forming member 100 is provided in the SCR unit 4 as shown in FIGS. More specifically, as shown in FIG. 2B, it is disposed in the inflow chamber 22 inside the case 20. The inflow chamber 22 forms part of a space (exhaust path) from the liquid reducing agent injection position to the SCR 16. The inflow chamber 22 is partitioned by the flow path forming member 100 into an upstream space and a downstream space.

  The flow path forming member 100 protrudes from the inner edge of the annular plate portion 101 toward the upstream end portion 23 of the case 20 (for example, to the side opposite to the SCR 16 side). And a substantially cylindrical protruding portion 103. The annular plate portion 101 is disposed so as to face the outer peripheral portion of the inflow surface of the SCR 16.

  Further, in the flow path forming member 100, a cutout portion 108 is formed by cutting out by a range of a predetermined angle α (see FIG. 2C) in a cross section perpendicular to the axial direction of the case 20. The notch 108 serves as a passage for the exhaust gas flowing into the upstream space to flow to the downstream space.

An edge portion 102 is formed on the outer periphery of the annular plate portion 101 over the entire outer periphery. The edge part 102 protrudes toward the same side as the side from which the protrusion part 103 protrudes.
A connection portion (for example, a corner between the annular plate portion 101 and the edge portion 102) between the annular plate portion 101 and the edge portion 102 is rounded. That is, it is formed in a curved shape.

  In addition, the annular plate portion 101 is curved so as to gradually rise toward the protruding portion 103 at the connection portion with the protruding portion 103. In the present embodiment, the annular plate portion 101 is continuous with the protruding portion 103 (see, for example, the cross section 108a of the notch portion 108 in FIG. 2D).

  The outer shape of the protrusion 103 is formed in a shape (tapered shape) that gradually becomes tapered. For example, the protrusion 103 has a shape that gradually narrows toward the tip. That is, the downstream space is formed so as to become wider as it is closer to the catalyst. A circular top 105 is formed at the protruding end of the protruding portion 103. The surface of the top part 105 is formed in a planar shape. In the present embodiment, the top portion 105 is formed in parallel to the flat portion of the annular plate portion 101.

  And since the external shape of the protrusion part 103 is formed in the taper shape as mentioned above, the diameter of the edge part 104 which is a connection part of the protrusion part 103 and the cyclic | annular board part 101 so that FIG. And the former is larger than the diameter of the top 105 described above.

A hole 107 is formed in the top portion 105. The hole 107 is continuous with the notch 108.
In the flow path forming member 100, in the IIC-IIC sectional view of FIG. 2C, the protruding portion 103 is not eccentric with respect to the annular plate portion 101, and the protruding portion 103 and the annular plate portion 101 are formed concentrically. ing. More specifically, the circular edge portion 104, the top portion 105, and the hole 107 are formed concentrically with the annular plate portion 101. However, they are not required to be strictly concentric. For example, at least two of the edge portion 104, the top portion 105, the hole 107, and the annular plate portion 101 may be eccentric in relation to each other. Moreover, all may be eccentric.

  As shown in FIG. 2C, the flow path forming member 100 passes through the center O ′ of the flow path forming member 100 (center O ′ as a circular center) and the center O of the case 20 (central axis in the longitudinal direction). It is arranged in the case 20 so as to coincide with the center O) as a point.

  The flow path forming member 100 is formed so as to fit within the case 20 while abutting the inner surface of the case 20 without a gap (see, for example, FIGS. 2B and 2C). Specifically, the flow path forming member 100 is disposed such that the edge portion 102 is in close contact with the inner peripheral surface 24 of the case 20 and the top portion 105 is in close contact with the upstream end portion 23 of the inflow chamber 22. That is, the flow path forming member 100 is formed such that the wall portion that separates the upstream space and the downstream space is not located on the central axis of the SCR 16.

  Furthermore, the flow path forming member 100 is disposed such that the cutout portion 108 is located farthest from the outlet of the communication path 14 in the circumferential direction of the inflow chamber 22 (see, for example, FIG. 2C). For example, the flow path forming member 100 is disposed so that the cutout portion 108 and the outlet of the communication passage 14 are located on opposite sides of the center O by 180 ° in the circumferential direction.

  Thus, a space (flow path) through which exhaust gas flows is formed by the annular plate portion 101, the edge portion 102, the protruding portion 103, the top portion 105, and the end portion 23 and the inner peripheral surface 24 of the case 20.

  Then, in the inflow chamber 22, the exhaust gas flows into the inflow chamber 22 from the outlet of the communication path 14 and circulates around the protrusion 103 so that the annular plate portion 101, the edge portion 102, and the protrusion of the flow path forming member 100. It flows through the space (flow path) formed by the portion 103 and the end portion 23 of the case 20 and the inner peripheral surface 24, and flows downstream through the notch portion 108 (SCR 16 side).

  The flow path forming member 100 is manufactured, for example, by drawing a plate-like metal. For example, the annular plate portion 101, the edge portion 102, the protruding portion 103, and the top portion 105 are integrally formed.

The effect of the exhaust gas purification apparatus 1 provided with such a flow path forming member 100 will be described later.
Here, in this embodiment, the “path” (flow path) is a path (flow path) through which exhaust gas flows. The “path” (flow path) from the outlet of the communication path 14 to the cutout portion 108 is a part or all of the space formed by the flow path forming member 100 and the case 20, and more specifically. , Part or all of the space formed by the annular plate portion 101, the edge portion 102, the protruding portion 103, and the end portion 23 and the inner peripheral surface 24 of the case 20. More specifically, it is a region in the space where exhaust gas can flow. The “path length” (flow path length) is the length of the path (flow path) through which the exhaust gas flows.

  Since there are infinite patterns as paths through which the exhaust gas can flow, in that sense, the path length value can also exist infinitely. Therefore, the “path” (flow path) from the exit of the communication path 14 to the notch 108 is, in one example, defined as the shortest path pattern from the exit of the communication path 14 to the notch 108. May be.

  Further, in the IIC-IIC cross-sectional view of FIG. 2C, the intermediate portion between the edge portion 102 of the flow path forming member 100 and the protruding portion 103 is connected in the region from the outlet of the communication passage 14 to the cutout portion 108. A route may be defined as a “route” (flow path).

  Further, in the region from the outlet of the communication passage 14 to the cutout portion 108, a portion where exhaust gas flows most easily is calculated by simulation or the like, and the calculated portion may be defined as a “path” (flow path). .

The “path length” (flow path length) can be defined as the length of the “path” (flow path) defined as described above.
(Modification 1)
3A to 3C are views showing a modification of the arrangement of the flow path forming member 100. FIG.

FIG. 3A is a diagram showing a part of the appearance of the SCR unit 4. 3B is a cross-sectional view taken along the line IIIB-IIIB in FIG. 3A. 3C is a cross-sectional view taken along the line IIIC-IIIC in FIG. 3A.
Here, it is assumed that the same flow path forming member as the flow path forming member 100 of FIGS. On the other hand, in the example of FIGS. 3A to 3C, the arrangement of the flow path forming member 100 is different from the example of FIGS.

  Specifically, in the example of FIGS. 3A to 3C, the positional relationship between the communication path 14 and the notch 108 is different from the example of FIGS. More specifically, in the example of FIGS. 2A to 2D, the flow path forming member 100 is disposed so that the notch 108 is located farthest from the outlet of the communication path 14 as described above. On the other hand, in the example of FIGS. 3A to 3C, the flow path forming member 100 is disposed in a state of being rotated around the centers O and O ′ as compared with the example of FIGS. 2A to 2D (for example, FIG. 3C reference). Specifically, the flow path forming member 100 is disposed in the case 20 by rotating 45 ° clockwise in the IIIC-IIIC sectional view of FIG. 3C. Thereby, regarding the length of the route from the exit of the communication passage 14 to the notch 108, the size of the route length R1 and the size of the route length R2 are different. Note that R1 <R2.

(Modification 2)
4A to 4D are partial explanatory views of the exhaust gas purifying apparatus 1 to which the flow path forming member 120 of the modification is applied.

  FIG. 4A is a diagram showing a part of the appearance of the SCR unit 4. 4B is a cross-sectional view taken along the line IVB-IVB in FIG. 4A. 4C is a cross-sectional view taken along the line IVC-IVC in FIG. 4A. FIG. 4D is a perspective view of the flow path forming member 120.

  In the following description, the main part of the flow path forming member 120 will be mainly described, and the description of the same configuration as the flow path forming member 100 will be omitted as appropriate. Regarding the flow path forming member 120, portions that are not specifically described may be configured similarly to the flow path forming member 100.

The flow path forming member 120 includes an annular plate portion 121 and a protruding portion 123 that protrudes from the annular plate portion 121 toward the upstream end portion 23 of the case 20.
On the outer periphery of the annular plate 121, an edge 122 is formed over the entire outer periphery. The edge part 122 protrudes toward the same side as the side from which the protruding part 123 protrudes.

  As shown in FIGS. 4C and 4D, the protruding portion 123 is formed so that the outer edge formed by the side wall 129 has a triangular shape. In addition, in the IVC-IVC cross-sectional view of FIG. 4C, a triangular center of gravity forming the protruding portion 123 is indicated by a symbol G.

  A triangular apex 125 is formed at the protruding end of the protruding portion 123 so as to match the triangular shape of the protruding portion 123. The surface of the top portion 125 is formed in a planar shape so as to be in close contact with the end portion 23 on the upstream side of the case 20.

  A connecting portion between the side wall 129 of the protruding portion 123 and the top portion 125 is rounded to form a curved portion 126. For example, the side wall 129 and the top portion 125 of the protruding portion 123 are continuous in a curved shape via the curved portion 126.

A triangular hole 127 is formed in the top portion 125. The hole 127 is continuous with a later-described notch 128.
In the flow path forming member 120, a notch 128 is formed. The cutout portion 128 is formed such that the width of the cutout increases toward the outside from the triangular center of gravity G forming the protruding portion 123 (see, for example, FIG. 4C). That is, the cutout portion 128 is formed so that the cross section 128a of the cutout portion 128 is gradually separated from the top portion 125 toward the outer edge portion 122.

  In this example, the flow path forming member 120 is formed such that the triangular center of gravity G forming the protrusion 123 coincides with the center O of the case 20 (and the circular center O ′ forming the flow path forming member 100). Is disposed in the case 20 (see, for example, FIG. 4C).

  Further, the flow path forming member 120 is disposed in the inflow chamber 22 so that the notch 128 is located farthest from the outlet of the communication path 14 (see, for example, FIG. 4C). For example, the flow path forming member 120 is disposed so that the notch 128 and the outlet of the communication path 14 are located on the opposite sides of 180 ° in the circumferential direction across the center O.

  Accordingly, a space (flow path) through which exhaust gas flows is formed by the annular plate portion 121, the edge portion 122, the protruding portion 123, the top portion 125, the end portion 23 of the case 20, and the inner peripheral surface 24.

  Then, the exhaust gas flows into the case 20 from the communication path 14, flows around the protrusion 123, reaches the notch 128, and then flows downstream (SCR 16 side).

(Modification 3)
5A to 5D are partial explanatory views of the exhaust gas purification apparatus 1 to which the flow path forming member 140 according to the modification is applied.

  FIG. 5A is a diagram showing a part of the appearance of the SCR unit 4. 5B is a VB-VB cross-sectional view in FIG. 5A. 5C is a cross-sectional view taken along the line VC-VC in FIG. 5A. FIG. 5D is a perspective view of the flow path forming member 140.

  In the following description, the main part of the flow path forming member 140 will be mainly described, and the description of the same configuration as that of the flow path forming member 100 will be omitted as appropriate. Regarding the flow path forming member 140, portions that are not specifically described may be configured similarly to the flow path forming member 100.

The flow path forming member 140 includes an annular plate portion 141 and a protruding portion 143 protruding from the annular plate portion 141 toward the end portion 23 on the upstream side of the case 20.
On the outer periphery of the annular plate portion 141, an edge portion 142 is formed over the entire outer periphery. The edge 142 protrudes on the same side as the side from which the protrusion 143 protrudes.

The protrusion 143 is formed in a substantially cylindrical shape as shown in FIG. 5D, and details are as follows.
The protrusion 143 has a circular top 145, and a circular hole 147 is formed in the top 145. The hole 147 is continuous with a notch 148 described later. In the flow path forming member 140, the circular center O ₁ forming the hole 147 has a circular shape forming the flow path forming member 140 when viewed along the line VC-VC (in the cross-sectional view of VC-VC in FIG. 5C). The protruding portion 143 is formed so as to be eccentric from the center O ′ (for example, the circular center O ′ forming the annular plate portion 141).

  A connection portion between the side wall 149 and the top portion 145 of the protruding portion 143 is rounded to form a curved portion 146. For example, the side wall 149 and the top portion 145 of the protruding portion 143 are continuous in a curved shape via the curved portion 146.

  Of the side wall 149 of the protruding portion 143, a portion indicated by reference numeral S2 on the cutout portion 148 side (hereinafter referred to as a side wall portion S2), and a portion on the opposite side to the circumferential direction when viewed from the cutout portion 148 is approximately 180 °. Thus, the inclination angle with respect to the annular plate portion 141 is different from the portion indicated by reference numeral S1 (hereinafter referred to as the side wall portion S1). For this reason, side wall part S1 and side wall part S2 differ in length.

  The side wall portion S1 has an angle substantially perpendicular to the annular plate portion 141. On the other hand, the side wall part S2 has a gentler angle with respect to the annular plate part 141 as compared with the side wall part S1. For this reason, the length of the side wall portion S1 is smaller than the length of the side wall portion S2. In other words, the length of the side wall portion S2 is larger than the length of the side wall portion S1.

In addition, the distance L1 between the side wall S1 and the edge 142 and the distance L2 between the side wall S2 and the edge 142 are substantially the same.
In the flow path forming member 140, a notch 148 is formed. The notch 148 is formed such that the width of the notch increases toward the outside from the circular center O ′ forming the flow path forming member 140 (see, for example, FIG. 5C). That is, the notch 148 is formed so that the cross-section 148a of the notch 148 is gradually separated from the top 145 toward the outer edge 142.

  In this example, the flow path forming member 140 is disposed in the inflow chamber 22 so that the notch 148 is located farthest from the outlet of the communication path 14 (see, for example, FIG. 5C). For example, the flow path forming member 140 is disposed so that the notch 148 and the outlet of the communication path 14 are located 180 ° opposite to each other across the center O ′.

  Accordingly, a space (flow path) through which exhaust gas flows is formed by the annular plate portion 141, the edge portion 142, the protruding portion 143, the top portion 145, and the end portion 23 and the inner peripheral surface 24 of the case 20.

  Then, the exhaust gas flows into the case 20 from the communication passage 14, flows around the protrusion 143, reaches the notch 148, and then flows downstream (SCR 16 side).

(Modification 4)
6A to 6D are partial explanatory views of the exhaust gas purifying apparatus 1 to which the flow path forming member 160 of a modified example is applied.

  FIG. 6A is a diagram showing a part of the appearance of the SCR unit 4. 6B is a cross-sectional view taken along the line VIB-VIB in FIG. 6A. 6C is a VIC-VIC cross-sectional view in FIG. 6A. FIG. 6D is a perspective view of the flow path forming member 160.

  6A to 6D, the same components as those of the flow path forming member 100 are denoted by the same reference numerals. Hereinafter, the flow path forming member 160 will be described focusing on differences from the flow path forming member 100.

  As shown in FIG. 6D, the flow path forming member 160 is provided with punching portions 161 each including a plurality of small holes 162 on both sides of the notch portion 108 adjacent to the notch portion 108. The punching part 161 may be provided only on one side with respect to the notch part 108.

  In this example, each of the two punching portions 161 includes eight small holes 162, but the number of the small holes 162, the place where the small holes 162 are formed, the size (diameter) of the small holes 162, and the small holes 108. The distance to the hole 162 is not limited at all.

  In this example, the flow path forming member 160 is disposed in the inflow chamber 22 so that the cutout portion 108 is located farthest from the outlet of the communication path 14 (see, for example, FIG. 6C). For example, the flow path forming member 160 is disposed so that the cutout portion 108 and the outlet of the communication passage 14 are located on opposite sides of the center O by 180 ° in the circumferential direction.

  As described above, the annular plate portion 101, the edge portion 102, the protruding portion 103, the top portion 105, and the end portion 23 and the inner peripheral surface 24 of the case 20 form a space (flow path) through which exhaust gas flows. It is as follows. On the other hand, the exhaust gas flows not only through the cutout portion 108 but also through the small hole 162 of the punching portion 161 to the downstream side (SCR 16 side).

(Modification 5)
7A to 7D are partial explanatory views of the exhaust gas purifying apparatus 1 to which the flow path forming member 180 of the modified example is applied.

  FIG. 7A is a diagram showing a part of the appearance of the SCR unit 4. 7B is a cross-sectional view taken along the line VIIB-VIIB in FIG. 7A. 7C is a VIIC-VIIC cross-sectional view in FIG. 7A. FIG. 7D is a perspective view of the flow path forming member 180.

  7A-7D, the same code | symbol is attached | subjected about the same structure as the flow-path formation member 100. FIG. Hereinafter, the flow path forming member 180 will be described focusing on differences from the flow path forming member 100.

  As shown in FIGS. 7C and 7D, the flow path forming member 180 has a notch 188 that is wider than the notch 108. Specifically, as shown in FIG. 7C, the notch 188 is formed by being cut out by a range of a predetermined angle β (β> α).

The cross sections 188a of the notches 188 are gradually separated from the top 105 toward the outer edge 102.
In this example, the flow path forming member 180 is disposed in the inflow chamber 22 so that the notch 188 is located farthest from the outlet of the communication path 14 (see, for example, FIG. 6C). For example, the flow path forming member 180 is disposed so that the notch 188 and the outlet of the communication passage 14 are positioned 180 ° opposite to each other across the center O.

  Thus, a space (flow path) through which exhaust gas flows is formed by the annular plate portion 101, the edge portion 102, the protruding portion 103, the top portion 105, and the end portion 23 and the inner peripheral surface 24 of the case 20. That is, the exhaust gas flows into the case 20 from the communication path 14, flows around the protrusion 103, reaches the notch 188, and then flows downstream (SCR 16 side).

(Modification 6)
8A to 8D are partial explanatory views of the exhaust gas purification apparatus 1 to which the flow path forming member 200 of the modification is applied.

  FIG. 8A is a diagram showing a part of the appearance of the SCR unit 4. 8B is a cross-sectional view taken along the line VIIIB-VIIIB in FIG. 8A. 8C is a sectional view taken along line VIIIC-VIIIC in FIG. 8A. FIG. 8D is a perspective view of the flow path forming member 200.

The flow path forming member 200 includes an annular plate portion 201 and a protruding portion 203 that protrudes from the annular plate portion 201 toward the upstream end portion 23 of the case 20.
On the outer periphery of the annular plate portion 201, an edge portion 202 is formed as a portion slightly raised from the annular plate portion 201 over the entire outer periphery. The outermost outer periphery of the edge 202 can be in close contact with the inner peripheral surface 24 of the case 20.

  In the flow path forming member 200, an extension wall 210 is formed so as to be continuous with the protruding portion 203 (so as to be continuous with the side wall 209 of the protruding portion 203). The extension wall 210 has the same height as the protruding portion 203 and is formed to stand on the annular plate portion 201 between the protruding portion 203 and the edge portion 202.

  A circular top 205 is formed at the protruding end of the protrusion 203, and a circular hole 207 is formed in the top 205. The hole 207 is continuous with a notch 208 described later. The surface forming the top 205 extends to the extension wall 210. Here, the top 205 may be understood as including the top of the extension wall 210.

  In the flow path forming member 200, a notch 208 is formed. In the flow path forming member 200, one of the notches 208 is delimited by an extension wall 210. For example, the notch 208 is formed between the extension wall 210 and the cross section 208a.

  The flow path forming member 200 is disposed in the case 20 so that the exhaust gas from the communication path 14 collides with the extension wall 210 itself or in the vicinity of the extension wall 210 (see FIG. 8C). At that time, the top portion 205 is in close contact with the end portion 23 on the upstream side of the case 20, and the outer periphery of the edge portion 202 is in close contact with the inner peripheral surface 24 of the case 20.

  Thus, a space (flow path) through which exhaust gas flows is formed by the annular plate portion 201, the edge portion 202, the protruding portion 203, the top portion 205, the extension wall 210, and the end portion 23 and the inner peripheral surface 24 of the case 20. The That is, the exhaust gas flows into the case 20 from the communication passage 14 and flows so as to go around the protrusion 203 about one turn by restricting the flow in one direction by the extension wall 210. It reaches the section 208 and then flows downstream (SCR 16 side).

(Modification 7)
9A to 9D are partial explanatory views of the exhaust gas purification apparatus 1 to which the flow path forming member 220 of the modification is applied.

  FIG. 9A is a diagram showing a part of the appearance of the SCR unit 4. 9B is a cross-sectional view taken along the line IXB-IXB in FIG. 9A. 9C is a cross-sectional view taken along IXC-IXC in FIG. 9A. FIG. 9D is a perspective view of the flow path forming member 220.

  The flow path forming member 220 is formed in an annular shape so as to have a U-shaped groove 221 that is recessed toward the center of the circular shape. Note that an outer edge 222 is formed on the outer edge of the flow path forming member 220 so as to protrude outward over the entire circumference of the outer edge.

Further, in the flow path forming member 220, a part is cut out with a predetermined width to form a cutout portion 228.
Such a flow path forming member 220 is disposed in the inflow chamber 22 so that the notch 228 is located farthest from the outlet of the communication path 14 (see, for example, FIG. 9C). For example, the flow path forming member 220 is disposed so that the notch 228 and the outlet of the communication path 14 are positioned 180 ° opposite to each other across the center O. For example, the edge 222 is in close contact with the inner peripheral surface 24 of the case 20.

  Thus, a space (flow path) through which exhaust gas flows is formed by the groove 221 and the inner peripheral surface 24 of the case 20. That is, the exhaust gas flows into the case 20 from the communication path 14, flows through the region corresponding to the concave portion of the groove 221, reaches the notch 228, and then flows downstream (SCR 16 side).

[Operation and effect of this embodiment]
Next, the operation and effect of this embodiment will be described with reference to FIGS.
FIG. 10 is an explanatory diagram showing the operation of the exhaust gas purification device 1 of the present embodiment. Here, description will be made by applying to the example of the flow path forming member 100.

  FIG. 10 shows a state where the flow path forming member 100 is disposed in the case 20. A communication path 14 is connected to the case 20, and an injection nozzle 26 for injecting the liquid reducing agent is provided in the communication path 14. In FIG. 10, the flow of the liquid reducing agent (vaporized reducing agent) injected from the injection nozzle 26 is indicated by arrows.

  In the following description, the flow of the vaporized reducing agent (hereinafter, also simply referred to as a reducing agent) will be described. However, it goes without saying that the description is not different from the case of the flow of exhaust gas containing the reducing agent. Yes.

  The reducing agent injected from the injection nozzle 26 first flows into the case 20 through the communication path 14. In the exhaust gas purification apparatus 1 of the present embodiment, the reducing agent that has flowed into the case 20 is a flow path formed by the flow path forming member 100 (a flow formed by the flow path forming member 100 and the case 20). Road). More specifically, as described above, it flows through the space formed by the annular plate portion 101, the edge portion 102, the protruding portion 103, and the end portion 23 and the inner peripheral surface 24 of the case 20.

  At this time, the reducing agent may collide with the projecting portion 103 of the flow path forming member 100 and branch (disperse) around the projecting portion 103, and flow around the projecting portion 103 along the side wall 109. . Then, the reducing agent finally reaches the notch 108. That is, the reducing agent is guided so as to change the flow direction by the outer peripheral surface (curved surface) of the protrusion 103 and to branch into a plurality (two in this example), and then merges from different directions. To the notch (the same opening) 108.

  The reducing agent that has flown around the protrusion 103 reaches the portion where the notch 108 is formed and collides with the portion, and flows downstream through the notch 108. That is, it flows toward the SCR 16.

  More specifically, the reducing agent colliding at the cutout portion 108 flows toward the SCR 16 through various routes. For example, a part enters the inside of the protrusion 103 (see also FIG. 1), and flows from the central portion of the protrusion 103 (the central portion of the flow path forming member 100) to the SCR 16. For example, the reducing agent that has flowed into the inflow chamber 22 from the communication path 14 flows so as to return to the communication path 14 side, and then flows to the SCR 16. A part of the cutout 108 flows from the widest portion to the SCR 16 side as it is.

  The protruding portion 103 is formed in a substantially cylindrical shape (that is, the inside of the protruding portion 103 is formed in a hollow shape), and the hole 107 and the notch portion 108 are continuous so that they collide at the notch portion 108. The reducing agent can flow not only in the space on the downstream side of the cutout portion 108 but also in the protrusion 103. That is, more space in which the reducing agent can diffuse is secured. For this reason, diffusion and vaporization of the reducing agent are effectively promoted.

The notch 108 corresponds to an example of a merging portion of the present embodiment. Moreover, it corresponds to an example of an opening.
As described above, in the present embodiment, the path length from when the reducing agent flows around the protrusion 103 to the SCR 16 is increased by the amount of the reducing agent injected from the injection nozzle 26. That is, after the reducing agent is injected from the injection nozzle 26 and then flows into the case 20 and does not directly reach the SCR 16, it flows through the space (flow path) formed by the flow path forming member 100 and the case 20, The SCR 16 is reached through the notch 108 of the flow path forming member 100. For example, the space (flow path) formed by the flow path forming member 100 and the case 20 ensures more time and path length until the exhaust gas reaches the SCR 16.

As a result, a sufficient time and path length for diffusion and vaporization of the reducing agent are ensured, the reducing agent can diffuse more uniformly in the exhaust gas, and the decomposition action is promoted. For this reason, in the SCR 16, reduction processing of NO _x in the exhaust gas can be performed more efficiently.

  In particular, according to this embodiment, it is only necessary to arrange the flow path forming member 100 in the inflow chamber 22, and the above-described effects can be obtained without changing other configurations of the exhaust gas purification device 1. Can do.

Therefore, the efficiency of the reduction process of NO _{x in} the exhaust gas can be improved without changing the size of the exhaust gas purification device 1 (without increasing the size of the exhaust gas purification device 1).

FIG. 11 is a graph showing the effect of the exhaust gas purification device 1 of the present embodiment.
FIG. 11 shows an example (example (1)) in which the flow path forming member 100 of the present embodiment is provided and a conventional example (examples (2) to (5)) in which the flow path forming member of the present embodiment is not provided. It is a figure which shows the comparison result of an effect. Specifically, in the case where the reducing agent is injected from the injection nozzle 26, it is a diagram showing a result of comparing the mass of vaporized ammonia (mass of gaseous ammonia). The injection amount of the reducing agent is the same in all the examples (1) to (5).

In FIG. 11, the horizontal axis represents time (sec), and the vertical axis represents the ammonia amount (mass of vaporized ammonia). The timing of time 0 is set as the timing for starting the injection of the reducing agent.
For each of the examples (1) to (5), “420 mm”, “310 mm”, “300 mm”, “290 mm”, and “280 mm” are described. The path length (the length of the flow path through which the exhaust gas flows) is shown. Here, a route is defined for each of the examples (1) to (5) using a common rule. The length of the defined route is defined as the route length.

  In example (1), the path length is 420 mm, which is a larger value than in other examples (2) to (5). This is because the path length increases by the amount of exhaust gas flowing through the space (flow path) formed by the flow path forming member 100 and the case 20.

  Referring to FIG. 11, first, it can be seen that in all of Examples (1) to (5), the mass of gaseous ammonia increases immediately after the injection of the reducing agent. That is, when a reducing agent is injected, the reducing agent diffuses and vaporizes to produce gaseous ammonia.

  However, especially in Examples (3) to (5), the mass of gaseous ammonia is smaller than that in Example (1) (and Example (2)). From this, it can be seen that in Examples (3) to (5), the mass (production amount) of gaseous ammonia is smaller than in Example (1). As a result, it is estimated that the diffusion of the reducing agent is not sufficient. Alternatively, it is presumed that the reducing agent (mixed gas of exhaust gas and reducing agent) reaches the SCR 16 before the reducing agent is sufficiently diffused and vaporized, and generation of gaseous ammonia is insufficient. .

  Moreover, although the mass (production amount) of gaseous ammonia is larger in Example (2) than in Examples (3) to (5), it is still smaller than in Example (1). . In addition, a drop in the mass (production amount) of gaseous ammonia is observed after a predetermined time. Therefore, also in Example (2), the diffusion of the reducing agent is not sufficient, or before the reducing agent is sufficiently diffused and vaporized, the reducing agent (mixed gas of exhaust gas and reducing agent) is added. It is estimated that the SCR 16 is reached and the generation of gaseous ammonia is insufficient.

  On the other hand, in Example (1), compared with Examples (2) to (5), the mass (production amount) of gaseous ammonia is large and stable. From this, it can be inferred that when the flow path forming member 100 is used, the reducing agent is sufficiently diffused into the exhaust gas and the generation of gaseous ammonia can be stabilized. For this reason, it is considered that the efficiency of the reduction process in the SCR 16 can be improved (or can be maintained).

[Function and effect of modification]
Depending on the positional relationship of the exhaust gas purification device 1 with respect to the vehicle body (not shown), it is conceivable that there are directions in which the exhaust gas does not easily flow around and the direction in which the exhaust gas easily flows around the protrusion 103 of the flow path forming member 100. In this case, in the example of FIGS. 2A to 2D, the exhaust gas flowing into the case 20 from the communication path 14 flows around the protrusion 103 and reaches the notch 108. Depending on the wraparound direction, the exhaust gas may reach the notch 108. It is also possible that a time difference occurs in time.

  In view of this point, as described in Modification 1 (FIGS. 3A to 3C), if the position of the notch 108 with respect to the outlet of the communication passage 14 is appropriately changed, the occurrence of the time difference as described above is suppressed, and reduction is performed. Uniform diffusion of the agent can be achieved. That is, considering the time difference, the difference between the path length R1 and the path length R2 is provided by the time difference, so that the time from the exhaust gas outlet to the notch 108 is reduced. It can be made substantially constant regardless of the gas path. In this case, the collision effect of the exhaust gas at the notch 108 can be made uniform, and mixing of the exhaust gas and the reducing agent (uniform diffusion and vaporization of the reducing agent) can be prevented.

  Moreover, in the modification 2 (FIG. 4A-4D), since the protrusion part 123 is formed in a triangle shape, compared with the example of FIG. 2A-2D in which the protrusion part 103 is formed circularly, exhaust gas is The length of the path when flowing around the protrusion 123 can be further increased. For example, it is conceivable that a larger path length can be secured by making the pattern of the path (flow path) through which the exhaust gas flows more complicated. For this reason, the uniform diffusion and vaporization of the reducing agent can be further promoted.

  In Modification 3 (FIGS. 5A to 5D), in particular, the side wall portion S1, which is a portion where the exhaust gas flowing in from the communication passage 14 collides, has an angle substantially perpendicular to the annular plate portion 141. When the exhaust gas flowing from the communication path 14 collides with the side wall S1, it can be more easily branched (dispersed) to the left and right. For this reason, it can be expected that the reducing agent is dispersed and flows, and the reducing agent diffuses and vaporizes more uniformly.

  In the modified example 4 (FIGS. 6A to 6D), it can be expected that the exhaust gas easily flows to the downstream side (SCR 16 side) through the punching portion 161 because the punching portion 161 is formed. In this case, as described above, the length of the exhaust gas is increased by the protrusion 103 or the like to promote uniform diffusion and vaporization of the reducing agent, while ensuring ease of flow of the exhaust gas to the downstream side (SCR 16 side). It can also be possible.

  The same applies to Modification 5 (FIGS. 7A to 7D). In the fifth modification, the notch 188 is formed wider than the notch 108. For this reason, it can be expected that the exhaust gas easily flows downstream (SCR 16 side). That is, the protrusion 103 and the like increase the path length of the exhaust gas as described above to promote uniform diffusion and vaporization of the reducing agent, and ensure ease of flow of the exhaust gas to the downstream side (SCR 16 side). It can also be possible.

  In the modified example 6 (FIGS. 8A to 8D), the flow of the exhaust gas is limited to only one direction by the extension wall 210. Specifically, the exhaust gas flowing from the communication path 14 into the case 20 is prevented from flowing to the side where the extension wall 210 is provided by the extension wall 210 and flows to the side where the extension wall 210 is not provided. Only allowed. In this case, the path length of the exhaust gas can be maximized, and it can be expected that the reducing agent diffuses and vaporizes more uniformly.

  In the modified example 7 ((FIGS. 9A to 9D), the exhaust gas flows through the U-shaped groove 221 and reaches the notch 228. However, when the exhaust gas flows through the U-shaped groove, Compared to other examples, it can be expected that the resistance is smaller, specifically, the flow of the exhaust gas is easily regulated by the U-shaped groove, for example, the flow of the exhaust gas is U-shaped. As a result, the flow direction can be stabilized and can be easily guided to the notch 228. Therefore, it can be expected that the exhaust gas flows more smoothly (smoothly reaches the SCR 16).

[Other Embodiments]
The exhaust gas purification device 1 of the present embodiment has been described above. However, the present invention is not limited to the above-described embodiment, and can take various forms within the technical scope of the present invention.

For example, in the second modified example, the protruding portion 123 is formed so that the outer edge has a triangular shape, but is not limited to a triangular shape, and may be formed in various polygonal shapes.
Further, in the modification 3 described above, the position of the center O ₁ may also be configured to eccentrically on the opposite side of the communication passage 14 with respect to the center O '. In which direction the eccentricity is performed is not limited. The direction of eccentricity may be another direction.

  Moreover, in the said modification 2-7, each flow path formation member may rotate and be arrange | positioned similarly to the case of the modification 1. Specifically, the length of the path from the outlet of the communication path 14 to the notch along the periphery of the protrusion of the flow path forming member can be different depending on the wraparound direction with respect to the protrusion. A path forming member may be provided.

  Further, in the above-described embodiment and each modification, a part of the flow path forming member is cut out by a predetermined angle range to form a cutout portion. The flow path forming member is not limited to the center position O ′, and may be set to another position. Further, the cutout portion may be formed by cutting out a part of the flow path forming member in parallel. Further, the cutout portion may be formed so as to gradually narrow toward the outside.

Further, a hole such as the small hole 162 may be provided instead of the notch (without providing the notch). Such a hole may be understood to be an example of an opening of the present invention.
Moreover, in the said embodiment, the surface of a flow-path formation member may be formed smoothly. For example, polishing may be performed or plating may be performed. In this case, a configuration in which at least a portion forming the exhaust gas flow path (the surface of the annular plate portion 101, the edge portion 102, and the protruding portion 103) is smoothly formed by polishing, plating, or the like is conceivable. According to this, it is conceivable that the flow of the exhaust gas becomes smooth.

  Alternatively, the surface of the flow path forming member may be a rough surface. Specifically, for example, irregularities may be formed on the surface of the flow path forming member. In this case, it is conceivable that at least the portions forming the exhaust gas flow paths (the surfaces of the annular plate portion 101, the edge portion 102, and the protruding portion 103) are rough. That is, it is conceivable that irregularities are formed in the portions (the surfaces of the annular plate portion 101, the edge portion 102, and the protruding portion 103) that form the exhaust gas flow path. According to this, it is conceivable that diffusion and vaporization of the reducing agent are promoted by forming a turbulent flow on such a rough surface.

  For example, as shown in FIG. 12A, a linear groove 301a is formed on the surface of the annular plate portion 101 along the exhaust gas flow direction (in this example, substantially parallel to the edge portion 102). May be.

  The outer peripheral surface of the protrusion 103 (an example of a guide surface) is linear along the flow direction (in this example, along the outer periphery of the protrusion 103 and substantially parallel to the edge 104). A groove 303a may be formed.

Each of the groove 301a and the groove 303a may be formed one by one or plural (in the example of FIG. 12A, three are formed each).
For example, the groove 301a and the groove 303a may be formed on the surface of the annular plate portion 101 and the outer peripheral surface of the protruding portion 103 by press molding.

According to the example of FIG. 12A, it can be expected that the exhaust gas can be guided more smoothly (smoothly reaches the SCR 16) by the grooves 301a and 303a.
The paths of the grooves 301a and 303a may be formed in any shape so that the exhaust gas flow forms a desired pattern. For example, the groove 303a may meander in the height direction of the protrusion so that exhaust gas is encouraged to flow so as to meander in the height direction of the protrusion 103 at least near the outer peripheral surface of the protrusion 103. Further, the groove 301a may meander so that exhaust gas is encouraged to meander in at least the vicinity of the surface of the annular plate portion 101. A groove may be provided between the circular edge portion 104 and only one of the surface of the annular plate portion 101 and the outer peripheral surface of the protruding portion 103.

Moreover, such a groove | channel may be applied to either the exhaust gas purification apparatus of embodiment mentioned above, or the exhaust gas purification apparatus of the modifications 1-7.
Further, for example, as shown in FIG. 12B, the linear plate-like portion 301b is formed on the surface of the annular plate portion 101 along the exhaust gas flow direction (in this example, substantially parallel to the edge portion 102). May be formed. The hook-shaped portion 301b has a shape in which a portion protruding in a mountain shape from the surface of the annular plate portion 101 is elongated and continuous.

  A linear hook-shaped portion 303b is formed on the outer peripheral surface of the protruding portion 103 along the flow direction (in this example, along the outer periphery of the protruding portion 103 and substantially parallel to the edge portion 104). May be.

Each of the hook-shaped portions 301b and the hook-shaped portions 303b may be formed one by one or plural (in the example of FIG. 12B, three are formed).
For example, the hook-shaped portion 301b and the hook-shaped portion 303b may be formed on the surface of the annular plate portion 101 and the outer peripheral surface of the protruding portion 103 by press molding.

According to the example of FIG. 12B, it can be expected that the exhaust gas can be guided more smoothly by the hook-shaped portion 301b and the hook-shaped portion 303b (more smoothly reach the SCR 16).
The path shape of the hook-shaped part 301b and the hook-shaped part 303b may be formed in any shape so that the flow of the exhaust gas forms a desired pattern. Further, the hook-shaped portion may be provided only on one of the surface of the annular plate portion 101 and the outer peripheral surface of the protruding portion 103.

Moreover, such a bowl-shaped part may be applied to either the exhaust gas purifying apparatus of the above-described embodiment or the exhaust gas purifying apparatuses of Modifications 1 to 7.
Further, for example, as shown in FIG. 13A, linear grooves 301 a and lines are formed on the surface of the annular plate portion 101 along the exhaust gas flow direction (in this example, substantially parallel to the edge portion 102). A hook-shaped portion 301b may be formed. Preferably, the groove 301a and the hook-shaped portion 301b are formed so as to be substantially parallel to each other. Further, the grooves 301a and the hook-shaped portions 301b may be alternately formed.

  On the outer peripheral surface of the protrusion 103, along the flow direction (in this example, along the outer periphery of the protrusion 103 and substantially parallel to the edge 104), the linear groove 303a and the linear groove A hook-shaped portion 303b may be formed. Preferably, the groove 303a and the bowl-shaped portion 303b are formed so as to be substantially parallel to each other. Further, the grooves 303a and the bowl-shaped portions 303b may be formed alternately.

For example, the grooves 301a and 303a and the flanges 301b and 303b may be formed on the surface of the annular plate portion 101 and the outer peripheral surface of the protruding portion 103 by press molding.
According to the example of FIG. 13A, it can be expected that the exhaust gas can be guided more smoothly (smoothly reaches the SCR 16) by the groove 301a and the hook-shaped part 301b, and the groove 303a and the hook-shaped part 303b.

  The shape of the groove 301a and the hook-shaped portion 301b and the path of the groove 303a and the hook-shaped portion 303b may be formed in any shape so that the flow of exhaust gas forms a desired pattern. Moreover, a groove | channel and a hook-shaped part may be provided only in any one of the surface of the cyclic | annular board part 101, and the outer peripheral surface of the protrusion part 103. FIG.

Moreover, such a groove | channel and a bowl-shaped part may be applied to either the exhaust gas purification apparatus of embodiment mentioned above, or the exhaust gas purification apparatus of the modifications 1-7.
Further, as shown in FIG. 13B, the flow path forming member 100 may have blade portions 310 and 311 for dispersing the exhaust gas. In this case, the flow path forming member 100 is preferably arranged such that the blade portions 310 and 311 face the outlet of the communication path 14.

The blade portions 310 and 311 are continuous with the edge portion 102 at the continuous portions 310a and 311a, and are separated from the edge portion 102 at the boundary ends 310b and 311b.
The boundary ends 310 b and 311 b are formed by providing a cut between the edge 102. And the blade | wing part 310 and the blade | wing part 311 are curving so that it may enter inside with respect to the edge part 102, so that it goes to the guide end parts 310c and 311c. Thereby, gaps 310d and 311d are formed between the boundary ends 310b and 311b and the edge portion 102.

In addition, a gap 312 is formed between the blade portion 310 and the blade portion 311. That is, the blade part 310 and the blade part 311 are separated with a gap 312 therebetween.
According to the flow path forming member 100 having such a configuration, at least part of the exhaust gas flowing into the space (inflow space) in the upstream chamber 22 from the communication path 14 passes through the gap 312 and enters the upstream space. Inflow. The exhaust gas is guided along the outer peripheral surface (guide surface) of the protrusion 103. Further, the remaining part of the exhaust gas hits the blade portions 310 and 311 and can flow into the upstream space along the outer surface of the blade portions 310 and 311.

  In such an example, the exhaust gas can be branched by the blade portions 310 and 311 and flow into the upstream space. For this reason, the diffusion of the exhaust gas is promoted, and as a result, the diffusion and vaporization of the reducing agent can be further promoted. Further, since the blade portions 310 and 311 are gently curved as described above, the exhaust gas hitting the blade portions 310 and 311 can be smoothly guided along the curved outer surface. For this reason, it can suppress that the flow of exhaust gas is impeded in the blade parts 310 and 311.

Two or more blade portions 310 may be provided, and two or more blade portions 311 may be provided. Further, only one of the blade part 310 and the blade part 311 may be provided.
Moreover, such a blade | wing part may be applied to either the exhaust gas purification apparatus of embodiment mentioned above, or the exhaust gas purification apparatus of the modifications 1-7.

  As shown in FIG. 14, an interposed member 302 a that is a member interposed between the outer surface and the inner peripheral surface 24 may be provided on the outer surface of the edge portion 102. An interposition member 305 a that is a member interposed between the surface (upper surface) and the end 23 may be provided on the surface (upper surface) of the top portion 105. In this embodiment, the interposed members 302a and 305a are formed in an annular shape.

  With the flow path forming member 100 disposed in the inflow chamber 22, the interposition member 302 a can be in close contact with the inner peripheral surface 24, and the interposition member 305 a can be in close contact with the end portion 23. Thereby, upstream space and downstream space can be divided more reliably. More specifically, the exhaust gas can be prevented from leaking from the edge portion 102 and the inner peripheral surface 24 or from the top portion 105 and the end portion 23 to the downstream space. That is, the exhaust gas can flow more reliably after reaching the downstream space, and the effect of the diffusion of the exhaust gas (and the diffusion and vaporization of the reducing agent in the exhaust gas) can be improved.

One each of the intervening members 302a and 305a may be provided, or two each of the intervening members 302a and 305a may be provided as shown in FIG.
Specifically, an interposition member 302 a having a different diameter may be provided on the outer surface of the edge portion 102. In addition, on the surface (upper surface) of the top portion 105, an interposed member 305a having a different diameter may be provided.

Further, three or more interposition members 302a and 305a may be provided. According to this, the sealing effect can be further improved.
The interposed members 302a and 305a may be made of metal, for example. For example, it may be formed from a mesh-like metal material.

The configuration in which the interposition member is provided may be applied to either the exhaust gas purification device of the above-described embodiment or the exhaust gas purification devices of Modifications 1 to 7.
Here, the flow path forming member may be fixed to the inflow chamber 22 by welding (welding). Spot welding may be used as a welding (welding) method. In this case, an interposition member may be provided if there is no problem in welding (welding). On the other hand, it is good also as not providing an interposed member suitably.

Note that the configurations of FIGS. 12A, 12B, and 13A may be combined with the configurations of FIGS. 13B and 14.
In the present embodiment, the space in the inflow chamber 22 corresponds to an example of the inflow space of the present invention. In addition, the annular plate portions 101, 121, 141, 201, the edge portions 102, 122, 142, 202, the protruding portions 103, 123, 143, 203, the top portions 105, 125, 145, 205, and the end portion 23 of the case 20 The space formed by the inner peripheral surface 24 corresponds to an example of the upstream space of the present invention. The space formed by the groove 221 and the inner peripheral surface 24 of the case 20 corresponds to an example of the upstream space. The space inside the protrusions 103, 123, 143, and 203 corresponds to an example of a downstream space. Further, the space at the center of the flow path forming member 220 corresponds to an example of a downstream space. Further, the notches 108, 128, 148, 188, 208, 228 correspond to an example of the opening of the present invention. The small hole 162 (or the punching portion 160) corresponds to an example of the opening portion of the present invention. The outer peripheral surfaces of the protrusions 103, 123, 143, and 203 and the surface of the groove 221 correspond to an example of a guide surface.

Claims (15)

An exhaust gas purifying device disposed in an exhaust passage of an internal combustion engine, wherein a case into which exhaust gas flows and a reducing agent that is provided in the case and consumes a reducing agent supplied into the case In an exhaust gas purifying device comprising a catalyst for reduction treatment,
A flow path forming member disposed in a space between the reducing agent supply position and the catalyst disposition position in the case and forming the exhaust gas flow path in the space. An exhaust gas purification device characterized by that.   The flow path forming member is configured to close a part of a path from the supply position of the reducing agent to the position where the catalyst is disposed in the space. The exhaust gas purification apparatus as described.   3. The exhaust gas purification device according to claim 1, wherein the flow path forming member includes a protrusion for branching the flow of the exhaust gas.   The exhaust gas purifying device according to claim 3, wherein the flow path forming member is configured to form a merging portion where the exhaust gas branched and flowed merges. A catalyst,
A case containing the catalyst, the case forming an exhaust flow path for discharging the inflowing exhaust gas after passing the catalyst;
A flow path forming member that is formed on the upstream side of the catalyst inside the case and divides an inflow space into which an exhaust gas for allowing the catalyst to pass flows into an upstream space and a downstream space;
With
In the flow path forming member,
The opening serving as a passage through which the exhaust gas flowing into the upstream space flows into the downstream space, the at least one opening communicating the upstream space and the downstream space;
An exhaust gas purifying device, characterized in that: a guide surface that guides the exhaust gas flowing into the upstream space so as to change the flow direction and guides the exhaust gas to the opening. The exhaust gas purification apparatus according to claim 5, wherein the guide surface guides the exhaust gas flowing into the upstream space so as to be branched into a plurality of branches and guides the exhaust gas to the opening. The exhaust gas purification device according to claim 6, wherein the guide surface guides the branched exhaust gas to the same opening. The exhaust gas purification apparatus according to claim 6 or 7, wherein the guide surface joins the branched exhaust gas from different directions. The exhaust gas purification according to any one of claims 6 to 8, wherein a groove is formed on the guide surface so as to continue from the exhaust gas inflow side toward the opening side. apparatus. The guide surface is formed with a hook-like portion that protrudes from the guide surface and that extends in an elongated shape from the exhaust gas inflow side to the opening side. The exhaust gas purification device according to any one of claims 6 to 9. The flow path forming member is formed such that a wall portion separating the upstream space and the downstream space is not positioned on a central axis of the catalyst. The exhaust gas purification device according to item 1. The exhaust gas purification device according to any one of claims 5 to 11, wherein the downstream space is formed so as to become wider as it is closer to the catalyst. The flow path forming member is:
An annular plate portion arranged to face the outer peripheral portion of the inflow surface of the catalyst;
A cylindrical projecting portion projecting from the inner edge of the annular plate portion to the side opposite to the catalyst side;
With
The inflow space is partitioned into the upstream space and the downstream space by the annular plate portion and the protruding portion,
At least a part of the outer peripheral surface of the protrusion functions as the guide surface,
The exhaust gas purification device according to any one of claims 5 to 12, wherein the opening is formed in at least one of the annular plate portion and the protruding portion. The exhaust gas purification device according to claim 13, wherein the protruding portion has a shape that gradually narrows toward the tip. The exhaust gas purifying device according to claim 13 or 14, wherein the flow path forming member is integrally formed with the annular plate portion and the protruding portion.

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