DE112014006547T5 - exhaust gas cleaning device - Google Patents

Abstract

Provided is an exhaust gas purification device which is arranged in an exhaust passage of an internal combustion engine. The exhaust gas purification device includes a housing into which an exhaust gas flows, and a catalyst provided in the housing, and performing a reduction treatment of the exhaust gas by consuming a reducing agent supplied in the housing. The exhaust gas purifier includes, within the housing, a flow path forming member disposed in a space extending from a position where the reducing agent is supplied to a position where the catalyst is disposed, and a flow path for the exhaust gas forms in the room.

Description

Related registrations

This application is a translation of the international patent application filed on 04.04.2014 with the international application number PCT / JP2014 / 059997 wherein the disclosure of this referenced application is expressly incorporated herein by reference.

FIELD OF THE INVENTION

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

GENERAL PRIOR ART

As means for purifying exhaust gas discharged from an internal combustion engine such as a gasoline engine and a diesel engine, there are known means for removing particulate matter in the exhaust gas and means for reducing and removing nitrogen oxides (NO _x ) in the exhaust gas.

As means for removing particulate matter, a device comprising a diesel particulate filter (DPF) has been developed (see, for example, Patent Document 1).

As means for reducing and removing NO _x , an apparatus comprising a selective reduction catalyst (SCR) for reducing NO _x has been developed (see, for example, Patent Document 2).

Due to the more stringent regulations on exhaust gases in recent years, an exhaust gas purifying apparatus including the diesel particulate filter for removing particulate matter and the SCR for reducing and removing NO _{x has also been} recommended (for example, see Patent Document 3).

DOCUMENTS OF THE STATE OF THE ART

PATENT DOCUMENTS

• Patent Document 1: Japanese Unexamined Patent Application Publication no. 2009-144672
• Patent Document 2: Japanese Unexamined Patent Application Publication no. 2007-332797
• Patent Document 3: Japanese Unexamined Patent Application Publication no. 2009-167806

BRIEF SUMMARY OF THE INVENTION TASKS TO BE SOLVED BY THE INVENTION

In the exhaust gas purification apparatus comprising the SCR, a liquid reducing agent is added to the exhaust gas, whereby the liquid reducing agent is evaporated. Then, the exhaust gas and the liquid reducing agent (vaporized reducing agent) are caused to reach the SCR in a mixed state. At the time, it is desirable that the liquid reducing agent is uniformly dispersed in the exhaust gas. For if the liquid reducing agent is not uniformly dispersed in the exhaust gas, components of the exhaust gas and the liquid reducing agent do not sufficiently react, resulting in reduced efficiency of NO _x decomposition.

Therefore, in the exhaust gas purification apparatus comprising the SCR, a distance from the injection port of the liquid reducing agent to the SCR should become as large as possible, so that the liquid reducing agent and the exhaust gas can be more reliably and uniformly mixed.

When the distance from the injection port of the liquid reducing agent to the SCR is designed to be as large as possible, the length of the entire device increases, particularly in the exhaust gas purification device including both the DPF and the SCR. As a result, the entirety of the device becomes larger, and problems such as a difficult mounting on vehicles can occur.

For example, in Patent Document 3, there is proposed a configuration in which a distance from the injection port of the liquid reducing agent to the SCR is made as large as possible while preventing the length of the entirety of the device from being increased by providing a first tubular housing containing the first DPF, and a second tubular housing containing the SCR, are arranged parallel to each other and by a connecting pipe from one end of the first tubular housing to an end of the second tubular housing extends obliquely. However, even such a design still requires a long spigot, which hinders the downsizing of the device.

In Patent Document 2, for example, a configuration is adopted in which a shielding plate is provided in an exhaust passage to thereby generate a swirling flow, and the liquid reducing agent is injected at a portion where the swirling flow is generated, so that the liquid reducing agent is effective even at a short distance, it evaporates (disperses). In this case, however, the injection port of the liquid reducing agent must be provided at the portion where the swirling flow is to be generated. That is, a different position of the injection port may be required than conventional. This may necessitate design changes not only of the exhaust gas purification device but also of a peripheral configuration for injecting the liquid reductant.

It is desirable to provide an exhaust gas purification device which can achieve a higher degree of both vehicle mountability and reduction treatment efficiency.

MEANS TO SOLVE THE TASKS

In one aspect, the present invention relates to an exhaust purification device disposed in an exhaust passage of an internal combustion engine. The exhaust gas purification device includes a housing into which an exhaust gas flows, and a catalyst provided in the housing, and performing the reduction treatment of the exhaust gas by consuming a reducing agent supplied to the housing. Moreover, the exhaust gas purification device of the present invention includes within the housing a flow path forming member disposed in a space extending from a position in which the reducing agent is supplied to a position where the catalyst is arranged, and which forms a flow path for the exhaust gas in the space. The reducing agent may be a liquid reducing agent.

According to one aspect of the present invention, the exhaust gas (specifically, the mixed gas containing the exhaust gas and the reducing agent) does not directly flow from the position in the space extending from the position where the reducing agent is supplied to the catalyst in which the reducing agent is supplied to the catalyst, but flows along the flow path formed by the flow path forming member to reach the catalyst. In this case, as compared with a case where the flow path forming member is not provided, a period and a path length over which the mixed gas containing the exhaust gas and the reducing agent can be increased from the position where the reducing agent is supplied is flowing to the catalyst. Consequently, more time and longer path length are ensured to disperse the reducing agent in the exhaust gas, and uniform dispersion and evaporation of the reducing agent can be further facilitated.

In this way, a longer flow path length (path length) of the exhaust gas is ensured without lengthening the flow path for the exhaust gas by, for example, providing a longer housing, and thus uniform dispersion and evaporation of the reducing agent can be facilitated, thus finally an efficiency of the reduction treatment of the exhaust gas through the catalyst.

Specifically, according to one aspect of the present invention, the flow path forming member may be configured to have in the space a part of a path extending from the position where the reducing agent is supplied to the position where the catalyst is arranged, to block.

This makes it possible to increase the flow path length of the exhaust gas by an additional length caused by a flow of the exhaust gas being interrupted at a blocked portion and by the exhaust gas reaching a downstream side after flowing to an unblocked portion ,

According to one aspect of the present invention, the flow path forming member may include a protruding portion that separates the flow of the exhaust gas.

This makes it possible to further facilitate the mixing of the exhaust gas and the reducing agent when the flow of the exhaust gas is separated, as compared with a case where the flow of the exhaust gas is in one direction. That is, the uniform dispersion and evaporation of the reducing agent is further facilitated, and the efficiency of the exhaust gas reducing treatment of the exhaust gas can be improved.

According to one aspect of the present invention, the flow path forming member may be configured to form a connecting portion to which the exhaust gas which has flowed separately is added thereto.

With such a configuration, the exhaust gas that has flowed separately is added to the connecting portion and is mixed, and thus the mixing of the exhaust gas and the reducing agent can be further facilitated. In this way, the uniform dispersion and evaporation of the reducing agent, thereby enabling improved efficiency of the exhaust gas reducing treatment by the catalyst as described above.

In another aspect, the present invention relates to an exhaust gas purification device comprising: a catalyst; a housing containing the catalyst and forming an exhaust gas flow path for allowing an exhaust gas that has flowed to pass through the catalyst and then discharged; and a flow path forming member which is upstream of the catalyst inside the housing, and which has an inflow space, which is a space into which the exhaust gas caused to pass through the catalyst, into an upstream space and a downstream one Room separated. The flow path forming member includes: at least one opening portion that allows the communication between the upstream space and the downstream space, and that forms a passage through which the exhaust gas that has flowed into the upstream space flows to the downstream space; and a guide surface that guides the exhaust gas that has flowed into the upstream space toward the opening portion such that a flow direction of the exhaust gas is changed.

With such a configuration, the exhaust gas that has flowed into the upstream space into the inflow space is guided to the opening portion such that the flow direction of the exhaust gas is changed, and flows from the opening portion of the downstream space (and to the catalyst). That is, a degree of freedom of the path for the exhaust gas, that is, where the exhaust gas flows into the inflow space to the catalyst is limited by the opening portion, and moreover, the exhaust gas is guided so that the flow direction of the exhaust gas is changed during the process, thereby the exhaust gas is guided into the opening section. Thus, the period and the path length over which the exhaust gas flows to the catalyst can be further increased. In addition, the dispersion of the exhaust gas is facilitated. Thereby, for example, when the mixed gas containing the exhaust gas and the reducing agent flows into the inflow space, uniform dispersion and evaporation of the reducing agent can be facilitated. The reducing agent may be one that reduces the exhaust gas by reaction with the catalyst.

According to another aspect, the guide surface may be configured to guide the exhaust gas that has flowed into the upstream space to the opening portion so that the exhaust gas is separated and guided through a plurality of paths. Characterized in that the exhaust gas is separated and guided over the plurality of paths to the opening portion, the dispersion of the exhaust gas is facilitated. Thus, for example, when the mixed gas containing the exhaust gas and the reducing agent flows into the inflow space, uniform dispersion and evaporation of the reducing agent can be facilitated. Accordingly, the efficiency of the reduction treatment of the exhaust gas by the catalyst can be improved.

According to another aspect of the present invention, the guide surface may be configured to guide the exhaust gas that has been separated to the opening portion as a single opening.

By guiding the exhaust gas, which has flowed separately, to the single port portion, the exhaust gas can be mixed at the port portion. This can further facilitate the mixing of the exhaust gas and the reducing agent, for example, when the mixed gas containing the exhaust gas and the reducing agent flows into the inflow space. For example, the uniform dispersion and evaporation of the reducing agent is facilitated. Accordingly, the efficiency of the reduction treatment of the exhaust gas by the catalyst can be improved.

According to another aspect of the present invention, the guide surface may be configured to allow the exhaust gas that has been separated to be added from different directions.

When the exhaust gas is added from the different directions, the flows of the exhaust gas meet at the connecting portion, and thus the mixing of the exhaust gas can be further facilitated as compared with a case where the exhaust gas from the same direction is added. Thereby, for example, when the mixed gas containing the exhaust gas and the reducing agent flows into the inflow space, the mixing of the exhaust gas and the reducing agent can be further facilitated. Accordingly, the efficiency of the reduction treatment of the exhaust gas by the catalyst can be improved.

According to another aspect of the present invention, the guide surface may have a groove formed therein, which is continuous from a side where the exhaust gas flows to a side at which the opening portion is provided.

Moreover, the guide surface may have a bead-shaped portion formed thereon, which is long and thin from the guide surface to which the exhaust gas flows to the side the opening portion is provided, protrudes and is continuous.

The groove and the bead-shaped portion may both be provided on the guide surface.

This allows the flow of the exhaust gas to be guided by the groove and / or the bulbous portion. In this case, the exhaust gas that has flowed into the upstream space can smoothly flow to the downstream space.

The shapes of the paths of the groove and the bead-shaped portion may be selected as necessary so that the flow of the exhaust gas forms a desired pattern. Depending on the shapes of the paths of the groove and / or the bulbous portion, the period and the path length over which the exhaust gas flows to the catalyst can be increased, and thus uniform dispersion and evaporation of the reducing agent in the exhaust gas can be facilitated.

According to another aspect of the present invention, the flow path forming member may be provided such that a wall portion that separates the upstream space and the downstream space is not positioned on a center axis of the catalyst.

The wall portion separating the upstream space and the downstream space is positioned closer to the catalyst relative to the seized upstream space. That is, the downstream space is smaller. Thus, in an embodiment in which the wall portion is positioned on the center axis of the catalyst, the downstream space is less easily secured on the center axis of the catalyst. On the other hand, the above-mentioned configuration makes it possible to maximize the downstream space on the center axis of the catalyst and to provide the path through which the exhaust gas flows more reliably.

According to another aspect of the present invention, the downstream space may be shaped to become larger toward the catalyst.

With such a configuration, the downstream space into which the exhaust gas may flow becomes larger as the exhaust gas comes closer to the catalyst, and thus the exhaust gas can more smoothly reach the catalyst.

According to another aspect of the present invention, the flow path forming member may include an annular cup portion disposed so as to face an outer peripheral portion of an inflow surface of the catalyst; and a protruding portion of a cylindrical shape that protrudes from an inner edge of the annular cup portion to an opposite side of the catalyst. The inflow space may be partitioned into the upstream space and the downstream space through the annular cup portion and the protruding portion, and at least a part of an outer peripheral surface of the protruding portion may serve as a guide surface. The opening portion may be provided in at least one of the annular cup portion and the protruding portion.

In such an embodiment, when the exhaust gas flows into the upstream space partitioned by the annular cup portion and the protruding portion, the exhaust gas strikes the protruding part and becomes along at least a part of the outer peripheral surface of the protruding portion (ie, the guide surface) guided the opening section. In this way, the path through which the exhaust gas flows is obtained, and the length of the path through which the exhaust gas flows can be increased by partitioning the inflow space into the upstream space and the downstream space. For example, when the mixed gas containing the exhaust gas and the reducing agent flows into the inflow space, the dispersion and evaporation of the reducing agent can be facilitated. Moreover, such an excellent effect can be obtained by making the flow path forming member having a simple shape comprising the annular cup portion and the protruding portion of cylindrical shape.

According to another aspect of the present invention, the protruding portion may have a shape gradually narrowing toward a front end of the protruding portion.

Such a configuration allows the downstream space to become larger toward the catalyst. In this case, the exhaust gas can flow through a larger space as the exhaust gas gets closer to the catalyst. With this configuration, it can be expected that the exhaust gas flows more smoothly through the downstream space to the catalyst. In addition, an uneven flow of the exhaust gas into the catalyst can be counteracted.

According to another aspect of the present invention, the annular cup portion and the protruding portion of the flow path forming member may be integrally formed.

This can for example lead to advantages in terms of manufacturing costs. This is also advantageous in terms of strength. In particular, a reduction in strength can be reduced and proper strength can be maintained.

According to another aspect of the present invention, the guide surface may be configured not to have a plane perpendicular to an inflow direction of the exhaust gas into the upstream space. Here, the plane refers continuously to a flat surface, wherein a curved surface and a linear projection are not covered by the surface. A major point here is that the guide surface is configured not to have a flat surface which is a surface perpendicular to the inflow direction and which has a specified range.

On the other hand, within the inventive concept of the present invention, it is acceptable that the guide surface has a portion that forms a line perpendicular to the inflow direction of the exhaust gas (a projection of linear shape). For example, within the spirit of the present invention, it is acceptable that the guide surface has a curved surface of which only an upper portion is perpendicular to the inflow direction of the exhaust gas.

With the configuration in which the guide surface does not have the plane perpendicular to the inflow direction of the exhaust gas into the upstream space, unnecessary interruptions of the flow of the exhaust gas into the upstream space by the guide surface can be suppressed. That is, the exhaust gas can flow more smoothly to the downstream room.

According to another aspect of the present invention, the guide surface may be a curved surface. This allows the exhaust gas to flow more smoothly to the downstream space because the exhaust gas is guided along the curved surface.

Moreover, at least one groove or a bead-shaped portion may be provided on a surface of the annular cup portion (on the surface of the annular cup portion facing a surface facing the outer peripheral portion of the inflow surface of the catalyst).

BRIEF DESCRIPTION OF THE DRAWINGS

1 FIG. 12 is a schematic diagram of an exhaust gas purification device of a present embodiment. FIG.

2A to 2D are explanatory partial diagrams of the exhaust gas purification device of the present embodiment.

3A to 3C are explanatory partial diagrams of an exhaust gas purification device of the modified example 1.

4A to 4D are explanatory partial diagrams of an exhaust gas purification device of the modified example 2.

5A to 5D are explanatory partial diagrams of an exhaust gas purification device of the modified example 3.

6A to 6D are explanatory partial diagrams of an exhaust gas purification device of the modified example 4.

7A to 7D are explanatory partial diagrams of an exhaust gas purification device of the modified example 5.

8A to 8D are explanatory partial diagrams of an exhaust gas purification device of the modified example 6.

9A to 9D are explanatory partial diagrams of an exhaust gas purification device of the modified example 7.

10 FIG. 10 is a graph showing a function of the exhaust gas purification device of the present embodiment. FIG.

11 FIG. 15 is a diagram showing an effect of the exhaust gas purification device of the present embodiment. FIG.

12A to 12B Fig. 10 are graphs showing elements of flow of change of modified examples.

13A to 13B Fig. 10 are graphs showing elements of flow of change of modified examples.

14 Fig. 10 is a diagram showing a flow path forming member of a modified example.

DECLARATION OF THE REFERENCE SIGNS

• 1 ... exhaust gas purification device, 2 ... DPF unit, 4 ... SCR unit, 6 ... DOC, 8th ... DPF, 10 ... Casing, 12 ... inlet, 14 ... communication passage, 16 ... SCR, 18 ... SLP, 20 ... Casing, 22 ... inflow chamber, 23 ... end section, 24 ... inner peripheral surface, 26 ... injector, 28 ... Exhaust pipe 30 ... exhaust hole, 100 . 120 . 140 . 160 . 180 . 200 . 220 ... flow path-forming element, 103 . 123 . 143 . 203 ... prominent section, 108 . 128 . 148 . 188 . 208 . 228 ... cutout section.

EMBODIMENTS OF THE INVENTION

An embodiment of the present invention will be explained below with reference to the drawings. It should be noted that in the present patent application, "path" and "flow path" are used in the same sense, and "path length" and "flow path length" are also used in the same sense.

[Design of the exhaust gas purification device]

An exhaust gas purification device 1 , shown in 1 Located along an exhaust passage of exhaust gas discharged from an internal combustion engine, such as a diesel engine, installed in a vehicle is a device that cleans exhaust gas. In 1 is a flow of the exhaust gas in the exhaust gas purification device 1 (A flow of the exhaust gas from an inlet to an outlet of the exhaust gas purification device 1 ) shown by arrows. However, the flow shown by the arrows is just one example. An example is, in particular, a flow made by arrows with dashed lines from an element forming the flow path 100 to an SCR 16 both described later, with flows in other forms also conceivable.

The exhaust gas purification device 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 with each other through a communication passage 14 coupled.

In the exhaust gas purification device 1 The exhaust gas discharged from the internal combustion engine first flows through an inlet 12 into the DPF unit 2 , Then be in the DPF unit 2 Solid particles in the exhaust gas bound and removed (burned). Thereafter, the exhaust gas flows over the communication passage 14 into the SCR unit 4 , In the SCR unit 4 For example, nitrogen oxides (NO _x ) in the exhaust gas are decomposed into nitrogen (N ₂ ) and water (H ₂ O) which are harmless components.

The DPF unit 2 includes a housing 10 a tubular shape (in particular, a circular cylindrical shape); a carrier 6 having an oxidation catalyst (Diesel Oxidation Catalyst: Diesel Oxidation Catalyst - DOC) (hereinafter referred to as DOC 6 designated); and a DPF 8th , The DOC 6 and the DPF 8th are in the case 10 included, and the DOC 6 is upstream of the DPF 8th arranged in the exhaust passage.

The DOC 6 causes an oxidation reaction of excess fuel in the exhaust gas. In one example, this excess fuel is effected by post-injection (additional injection after a combustion step) in the internal combustion engine. A temperature in the exhaust passage may be increased by reaction heat generated by the oxidation reaction.

The DPF 8th is a filter that filters the particulate matter in the exhaust gas, consists of porous ceramic material and has a lattice-like structure with many pores. The pores are pores opening on an end surface on an inlet side (upstream side) and closed on the end surface on an outlet side (downstream side), and pores closed on the end surface on the inlet side and opening at the end face on the outlet side, the pores being alternately provided.

The exhaust gas flows into the DPF 8th through the pores that attach to the end face on the inlet side of the DPF 8th Open, penetrates through boundary walls of the pores and flows through the pores, which open at the end face on the outlet side (downstream side), out to the downstream side. As the exhaust gas passes through the boundary walls, the solid particles become trapped in the exhaust gas and within the DPF 8th accumulated.

In the DPF unit 2 becomes an accumulated amount of the solid particles in the DPF 8th detected by a sensor, not shown. The DPF unit 2 is configured such that when it is determined based on a value detected by the sensor that the accumulated amount of the solid particles reaches or exceeds a predetermined amount, the temperature in the exhaust passage is increased. In this way, the solid particles are burned and removed.

The SCR unit 4 includes a housing 20 a tubular shape (in particular, a circular cylindrical shape); a carrier 16 comprising a Selective Catalytic Reduction (SCR) (hereinafter referred to as SCR 16 designated); and a carrier 18 comprising an oxidation catalyst for decomposing excess ammonia (Surplus Ammonia - SLP) (hereinafter referred to as SLP 18 ). The SCR 16 and the SLP 18 are in the case 20 included, and the SCR 16 is the SLP 18 upstream in the exhaust duct.

Specifically, the selective reduction catalyst (SCR) is a catalyst which decomposes NO _x contained in the exhaust gas into nitrogen (N ₂ ) and water (H ₂ O) by causing a reduction reaction with ammonia (NH ₃ ) produced by the degradation of a liquid reducing agent (described later) is generated. In particular, the oxidation catalyst for decomposing the excess ammonia (SLP) is an oxidation catalyst that decomposes excess ammonia that is not present in the SCR 16 is used.

On the downstream side of the SCR unit 4 is an exhaust pipe 28 intended. The exhaust pipe 28 has exhaust holes 30 which are formed in large numbers. The exhaust gas that passes through the SCR 16 and the SLP 18 has passed, flows through the exhaust holes 30 in the exhaust pipe 28 and is from the exhaust pipe 28 issued.

An inflow chamber 22 is on the upstream side of the SCR unit 4 provided (upstream of the SCR 16 ). Moreover, the exhaust gas purifier is 1 of the present invention configured so that the element forming the flow path 100 in the inflow chamber 22 is arranged, as will be described later.

The communication passage 14 has an injection nozzle 26 which is arranged, the liquid reducing agent in the communication passage 14 (for example, into the exhaust gas). For example, a urea solution can be used as a liquid reducing agent. The liquid reducing agent coming from the injector 26 is injected, is dispersed in the exhaust gas, evaporated and decomposed after the reaction with components of the exhaust gas into ammonia (NH ₃ ) and so on.

[Structure of the flow path forming member]

Regarding 2A to 2D will be an explanation regarding the exhaust gas purification device 1 given in which the flow path forming element 100 as an example is used.

2A is a graphical representation of an appearance of the SCR unit 4 , 2 B is a cross-sectional view along a line IIB-IIB in 2A , 2C is a cross-sectional view taken along a line IIC-IIC in 2A , 2D is a perspective view of the flow path forming element 100 ,

As in 2A to 2C is the element forming the flow path 100 in the SCR unit 4 intended. In particular, as in 2 B is the element forming the flow path 100 in the inflow chamber 22 inside the case 20 arranged. The inflow chamber 22 is part of a space (an exhaust path) that extends from a position where the liquid reducing agent enters the SCR 16 is injected. The inflow chamber 22 is through the element forming the flow path 100 divided into an upstream room and a downstream room.

The element forming the flow path 100 includes an annular cup portion 101 formed in a ring-like shape; and a protruding section 103 an approximately cylindrical shape that is from an inner edge of the annular plate portion 101 to an end section 23 on the upstream side of the housing 20 protrudes (for example, to an opposite side of the SCR 16 ). The annular plate section 101 is disposed so as to be an outer peripheral portion of an inflow surface of the SCR 16 is facing.

The element forming the flow path 100 has a cutout section 108 by cutting out a range of a predetermined angle α (see FIG 2C ) is formed on a portion perpendicular to an axial direction of the housing 20 is. The cutout section 108 becomes a passage through which the exhaust gas which has flowed into the upstream space flows into the downstream space.

Provided on an outer circumference of the annular plate portion 101 is an edge section 102 which is formed over the entire outer circumference. The edge section 102 stands out on the same side to which the protruding section 103 protrudes.

A connection between the annular plate portion 101 and the edge portion 102 (For example, a corner between the annular edge portion 101 and the edge portion 102 ) is rounded. That is, the connection has a curved shape.

Moreover, the annular disc portion 101 bent, in conjunction with the protruding section 103 so that it gradually becomes the protruding section 103 increases. In the present embodiment, the annular disc portion 101 continuous with the protruding section 103 (see, for example, sections 108a of the cutting section 108 in 2D ).

A contour of the protruding section 103 is shaped to gradually taper (has a rejuvenated shape). For example, the protruding section 103 a shape gradually to a front end of the protruding part 103 becomes narrower. That is, the Downstream space is shaped so that it becomes larger towards the catalyst. The protruding section 103 has an upper section 105 a circular shape at one end of a protruding side of the protruding portion 103 is formed. An area of the upper section 105 has a flat shape. In the present embodiment, the upper portion 105 parallel to a flat portion of the annular disc portion 101 ,

Because the contour of the protruding section 103 As previously described, having the tapered shape is a diameter of a circular edge 104 that connects the protruding section 103 and the annular plate portion 101 is larger than the upper section 105 , as in 2D can be seen.

The upper section 105 has a hole 107 auf, which is formed in it. The hole 107 is consistent with the cutout section 108 ,

As in the sectional view taken along the line IIC-IIC of 2C can be seen, is the protruding section 103 in the flow path forming element 100 not eccentric with respect to the annular cup portion 101 , and the protruding section 103 and the annular plate portion 101 are concentric with each other. In particular, the circular edge 104 , the upper section 105 and the hole 107 concentric with the annular disc portion 101 intended. However, they are not required to be strictly concentric with each other. For example, at least two, the circular edge 104 , the upper section 105 , the hole 107 or the annular plate portion 101 be eccentric to each other. Optionally, all of them can be eccentric to one another.

As in 2C is the element forming the flow path 100 inside the case 20 arranged so that a center O 'of the flow path forming element 100 (the center O 'as a center of the circular shape) and a center O of the housing 20 (the center O as a point through which a longitudinal center axis passes) coincide with each other.

The element forming the flow path 100 is formed such that it is inside the housing 20 is fitted while there is an inner surface of the housing 20 touched without a gap remaining (see, for example 2 B and 2C ). In particular, this is the element forming the flow path 100 arranged such that the edge portion 102 in close contact with an inner peripheral surface 24 of the housing 20 is, and such that the upper section 105 in close contact with the end portion 23 the upstream side of the inflow chamber 22 is. That is, the element forming a flow path 100 is formed such that a wall portion that separates the upstream space from the downstream space does not rest on a center axis of the SCR 16 located.

Moreover, this is the element forming the flow path 100 arranged such that the cutout section 108 in a circumferential direction of the inflow chamber 22 furthest from an outlet of the communication passage 14 is positioned remotely (see, for example 2C ). For example, this is the flow path forming element 100 arranged such that the cutout section 108 and the outlet of the communication passage 14 are positioned 180 ° circumferentially across the center O opposite each other.

In this way, a space (flow path) through which the exhaust gas flows from the annular disc portion 101 , the edge section 102 , the protruding section 103 , the upper section 105 and the end section 23 and the inner peripheral surface 24 of the housing 20 educated.

In the inflow chamber 22 the exhaust gas flows from the outlet of the communication passage 14 into the inflow chamber 22 and flows through the space (flow path) of the annular plate portion 101 , the edge section 102 and the protruding section 103 of the flow path forming element 100 and the end section 23 and the inner peripheral surface 24 of the housing 20 is formed, such that it is around the protruding section 103 gets around. Then the exhaust gas flows over the cutout section 108 to the downstream side (to the SCR 16 ).

The element forming the flow path 100 is made for example by deep drawing a metal plate. For example, the annular plate portion 101 , the edge section 102 , the protruding section 103 and the top section 105 formed in one piece.

Functions and effects of the emission control system 1 comprising the previously described flow path forming element 100 , will be described later.

In the present embodiment, "path" (flow path) means a path (flow path) through which the exhaust gas flows. The "path" (flow path) from the outlet of the communication passage 14 to the cutout section 108 is part of the space or the entire space of the element forming the flow path 100 and the housing 20 is formed. In particular, one is such path (flow path) part of the space or the entire space, the of the annular plate portion 101 , the edge section 102 , the protruding section 103 and the end section 23 and the inner peripheral surface 24 of the housing 20 is formed. Moreover, such a path (flow path) is particularly an area where the exhaust gas could flow in the space. Moreover, "path length" (flow path length) means a length of the path (flow path) through which the exhaust gas flows.

Since there can be an infinite number of patterns of the paths through which the exhaust flows, there could also be an unlimited number of path length values in this sense. By way of example, the shortest of the patterns can thus be from the outlet of the communication passage 14 to the cutout section 108 as the "path" (flow path) from the outlet of the communication passage 14 to the cutout section 108 To be defined.

Optionally, in the sectional view taken along the line IIC-IIC of 2C a path formed by connecting center portions between the edge portion 102 and the protruding section 103 of the flow path forming element 100 in an area extending from the outlet of the communication passage 14 to the cutout section 108 extends as the "path" (flow path) are defined.

Optionally, a path in which the exhaust gas most likely to flow, which is determined by simulation or the like, may be in the area extending from the outlet of the communication passage 14 to the cutout section 108 extends as the "path" (flow path) are defined.

In this regard, the "path length" (flow path) may be defined as the length of the "path" (flow path) as defined above.

(Modified Example 1)

3A to 3C FIG. 16 is graphs showing a modified example of an arrangement shape of the flow path forming member. FIG 100 demonstrate.

3A is a graphical representation that is part of an appearance of the SCR unit 4 shows. 3B is a sectional view taken along a line IIIB-IIIB in 3A , 3C is a sectional view taken along a line IIIC-IIIC in 3A ,

It is assumed that a flow path forming member which is the same as the flow path forming member is used 100 in the 2A to 2D , On the other hand, in the example in 3A to 3C the arrangement form of the flow path forming element 100 different from that in the example in 2A to 2D ,

In particular, in the example in 3A to 3C a positional relationship between the communication passage 14 and the cutout section 108 different from that in the example in 2A to 2D , In particular, in the example in 2A to 2D the element forming the flow path 100 arranged such that the cutout section 108 furthest from the outlet of the communication passage 14 is removed as previously described. On the other hand, in the example in 3A to 3C the element forming the flow path 100 arranged in such a state that it compared with the example in 2A to 2D rotated around the centers O and O '(see, for example 3C ). In particular, in the sectional view along the line IIIC-IIIC of 3C the element forming the flow path 100 in the case 20 mounted clockwise by 45 °. Regarding the path length from the outlet of the communication passage 14 to the cutout section 108 Because of such arrangement, a value for a path length R1 and a value for a path length R2 are different from each other. In this case R1 <R2 applies.

(Modified Example 2)

4A to 4D are explanatory partial graphic representations of the exhaust gas purification device 1 in which a flow path forming element 120 a modified example is used.

4A is a graphical representation of the appearance of the SCR unit 4 , 4B is a sectional view taken along a line IVB-IVB in 4A , 4C is a sectional view taken along a line IVC-IVC in 4A , 4D is a perspective view of the flow path forming element 120 ,

In the following, mainly more significant portions of the flow path forming member will become 120 explains, with an explanation of a structure, the structure of the flow path forming element 100 is similar, is omitted if necessary. Portions of the flow path forming element 120 not specifically explained in detail, may be similar to the flow path forming element 100 be designed.

The element forming the flow path 120 includes an annular cup portion 121 and a protruding section 123 that of the annular plate portion 121 to the end section 23 on the upstream side of the housing 20 protrudes.

Provided on an outer circumference of the annular plate portion 121 is an edge section 122 which is formed over the entire outer circumference. The edge section 122 stands out on the same side to which the protruding section 123 protrudes.

As in 4C and 4D shown is the protruding section 123 shaped such that a shape of an outer edge, that of a side wall 129 is formed, is a triangular shape. In the sectional view taken along the line IVC-IVC of 4C The center of gravity of the triangular shape is the protruding section 123 forms marked by a symbol G.

Provided at one end of the protruding part 123 on a protruding side thereof is an upper section 125 a triangular shape corresponding to the triangular shape, the protruding section 123 forms. An area of the upper section 125 has a flat shape so that it is capable of being in close contact with the end portion 23 on the upstream side of the housing 20 to be.

A connection between the side wall 129 of the protruding section 123 and the upper section 125 is rounded to make a curved section 126 to build. For example, the sidewall 129 of the protruding section 123 and the upper section 125 bent over the curved section 126 consistently with each other.

The upper section 125 has a hole 127 a triangular shape formed therein 125 on. The hole 127 is with a cutout section 128 consistently, which will be described later.

The element forming the flow path 120 has the cutout section 128 auf, which is formed in it. The cutout section 128 is shaped such that a width of a portion of the center of gravity G of the triangular shape, which is the protruding portion 123 forms outward becomes larger (see, for example 4C ). In particular, the cutout section 128 shaped so that cuts 128a of the cutting section 128 gradually from the upper section 125 to the edge portion 122 that is outside the top section 125 is located farther apart.

In the present example, this is the flow path forming element 120 inside the case 20 arranged such that the center of gravity G of the triangular shape, which is the protruding portion 123 forms, with the middle O of the housing 20 (and the center O 'of the circular shape forming the flow path forming element 100 forms) (see, for example 4C ).

Moreover, this is the element forming the flow path 120 in the inflow chamber 22 arranged so that the cutout section 128 furthest from the outlet of the communication passage 14 is positioned remotely (see, for example 4C ). For example, this is the flow path forming element 120 arranged such that the cutout section 128 and the outlet of the communication passage 14 are positioned at 180 ° in a circumferential direction across the center O opposite to each other.

In this way, through the annular plate portion 121 , the edge section 122 , the protruding section 123 , the upper section 125 and the end section 23 and the inner peripheral surface 24 of the housing 20 a space (flow path) is formed, through which the exhaust gas flows.

The exhaust gas flows through the communication passage 14 in the case 20 , flows to the cutting section 128 such that it is around the protruding section 123 gets around and then flows to the downstream side (to the SCR 16 ).

(Modified Example 3)

5A to 5D are explanatory partial graphic representations of the exhaust gas purification device 1 in which the flow path forming element 140 a modified example is used.

5A is a graphical representation that is part of an appearance of the SCR unit 4 shows. 5B is a sectional view taken along a line VB-VB in 5A , 5C is a sectional view taken along a line VC-VC in 5A , 5D is a perspective view of the flow path forming element 140 ,

In the following, mainly more significant portions of the flow path forming member will become 140 explains, with an explanation of a structure, the structure of the flow path forming element 100 is similar, is omitted if necessary. Portions of the flow path forming element 140 not specifically explained in detail, may be similar to the flow path forming element 100 be designed.

The element forming the flow path 140 includes an annular cup portion 141 and a protruding section 143 that of the annular plate portion 141 to the end section 23 on the upstream side of the housing 20 protrudes.

Provided on an outer circumference of the annular plate portion 141 is an edge section 142 which is formed over the entire outer circumference. The edge section 142 is the same side to which the protruding section 143 protrudes.

As in 5D shown, the protruding section 143 an approximately cylindrical shape, the details of which are set forth below.

The protruding section 143 has an upper section 145 circular shape, and the upper section 145 has a hole 147 a circular shape formed therein. The hole 147 is consistent with a cutout section 148 which will be described later. In the element forming the flow path 140 is the protruding section 143 is formed such that, in an arrow view, along the line VC-VC (in the sectional view taken along the line VC-VC of FIG 5C ) the center O _{1 of} the circular shape, the hole 147 is eccentric with respect to the center O 'of the circular shape which constitutes the flow path forming member 140 forms (the center O 'of the circular shape, for example, the annular plate portion 141 forms).

A connection between a side wall 149 of the protruding section 143 and the upper section 145 is rounded to make a curved section 146 to build. For example, the sidewall 149 of the protruding section 143 and the top section 145 over the curved section 146 in a curved way consistently with each other.

In the sidewall 149 of the protruding section 143 are a section located on one side of the cutout section 148 and a portion shown by a symbol S2 (hereinafter described as a side wall portion S2) and a portion extending approximately 180 degrees in a circumferential direction on the opposite side of the cutout portion 148 and shown by a symbol S1 (hereinafter described as a side wall portion S1) at mutually different angles with respect to the annular cup portion 141 inclined. Thus, the side wall portion S1 and the side wall portion S2 are different from each other in length.

The side wall portion S1 has an approximately perpendicular angle with respect to the annular cup portion 141 on. On the other hand, the side wall portion S2 has a shallower angle with respect to the annular cup portion 141 on as the side wall portion S1. Thus, a length of the side wall portion S1 is shorter than that of the side wall portion S2. Conversely, the length of the side wall portion S2 is longer than that of the side wall portion S1.

A distance L1 between the side wall portion S1 and the edge portion 142 and a distance L2 between the side wall portion S2 and the edge portion 142 are about the same.

The element forming the flow path 140 has the cutout section 148 auf, which is formed in it. The cutout section 148 is formed such that a width of a cutout from the center O 'of the circular shape forming the flow path forming member 140 forms outwardly becomes larger (see, for example 5C ). In particular, the cutout section 148 shaped so that cuts 148a of the cutting section 148 gradually from the upper section 145 to the edge portion 142 that is outside the top section 145 is located farther apart.

In the present example, this is the flow path forming element 140 in the inflow chamber 22 arranged such that the cutout section 148 furthest from the outlet of the communication passage 14 is positioned remotely (see, for example 5C ). For example, this is the flow path forming element 140 arranged such that the cutout section 148 and the outlet of the communication passage 14 are positioned 180 ° in the circumferential direction across the center O 'opposite each other.

In this way, a space (flow path) through which the exhaust gas flows becomes from the annular disc portion 141 , the edge section 142 , the protruding section 143 , the upper section 145 and the end section 23 and the inner peripheral surface 24 of the housing 20 educated.

The exhaust gas flows through the communication passage 14 in the case 20 , flows to the cutting section 148 such that it is around the protruding section 143 around, and then flows to the downstream side (to the SCR 16 ).

(Modified Example 4)

6A to 6D are explanatory partial graphic representations of the exhaust gas cleaning device 1 in which the flow path forming element 160 a modified example is used.

6A is a graphical representation that is part of an appearance of the SCR unit 4 shows. 6B is a sectional view taken along a line VIB-VIB in FIG 6A , 6C is a sectional view taken along a line VIC-VIC in 6A , 6D is a perspective view of the flow path forming element 160 ,

In 6A to 6D are the same elements as those of the flow path forming element 100 assigned the same reference numerals. Subsequently, the element forming the flow path becomes 160 with emphasis on differences from the element forming the flow path 100 lies.

As in 6D shown has the element forming the flow path 160 a puncture section 161 on, comprising a plurality of small holes 162 next to the cutout section 108 on each side of the cut-out section 108 are provided.

The puncture section 161 can also only on one side of the cutout section 108 be provided.

In the present example, the two puncture sections comprise 161 eight small holes each 162 ; the number of small holes 162 , a spot where the small holes 162 are provided, a size (diameter) of the small holes 162 and a distance from the cutout portion 108 to the small holes 162 are not limited.

In the present example, this is the flow path forming element 160 in the inflow chamber 22 arranged so that the cutout section 108 furthest from the outlet of the communication passage 14 is positioned remotely (see, for example 6C ). For example, this is the flow path forming element 160 arranged such that the cutout section 108 and the outlet of the communication passage 14 are positioned 180 ° in a circumferential direction across the center O opposite each other.

As described above, a space (flow path) through which the exhaust gas flows becomes from the annular disc portion 101 , the edge section 102 , the protruding section 103 , the upper section 105 and the end section 23 and the inner peripheral surface 24 of the housing 20 educated. On the other hand, the exhaust gas does not flow only over the cutout portion 108 but also over the small holes 162 of the puncture section 161 to the downstream side (to the SCR 16 ).

(Modified Example 5)

7A to 7D are explanatory partial graphic representations of the exhaust gas purification device 1 in which the flow path forming element 180 a modified example is used.

7A is a graphical representation that is part of an appearance of the SCR unit 4 shows. 7B is a sectional view taken along a line VIIB-VIIB in FIG 7A , 7C is a sectional view taken along a line VIIC-VIIC in FIG 7A , 7D is a perspective view of the flow path forming element 180 ,

In 7A to 7D are the same elements as those of the flow path forming element 100 the same reference numerals assigned. Subsequently, the element forming the flow path becomes 180 with emphasis on differences from the element forming the flow path 100 lies.

As in 7C and 7D shown has the element forming the flow path 180 a cutout section 188 which is made wider than the cutout section 108 , In particular, as in 7C shown, the cutting section 188 by cutting out a range of a predetermined angle β (β> α).

sections 188a of the cutting section 188 are from the upper section 105 to the edge portion 102 that is outside the top section 105 lies, gradually complained of each other.

In the present example, this is the flow path forming element 180 in the inflow chamber 22 arranged such that the cutout section 188 furthest from the outlet of the communication passage 14 is positioned remotely (see, for example 6C ). For example, this is the flow path forming element 180 arranged such that the cutout section 188 and the outlet of the communication passage 14 are positioned 180 ° circumferentially across the center O opposite each other.

In this way, through the annular plate portion 101 , the edge section 102 , the protruding section 103 , the upper section 105 and the end section 23 and the inner peripheral surface 24 of the housing 20 a space (flow path) is formed, through which the exhaust gas flows. In particular, the exhaust gas flows through the Communication passage 14 in the case 20 , flows to the cutout section 188 such that it is around the protruding section 103 and then flows to the downstream side (to the SCR 16 ).

(Modified Example 6)

8A to 8D are explanatory partial graphic representations of the exhaust gas purification device 1 in which the flow path forming element 200 a modified example is used.

8A is a graphical representation that is part of an appearance of the SCR unit 4 shows. 8B is a sectional view taken along a line VIIIB-VIIIB in 8A , 8C is a sectional view taken along a line VIIIC-VIIIC in 8A , 8D is a perspective view of the flow path forming element 200 ,

The element forming the flow path 200 includes an annular cup portion 201 and a protruding section 203 that of the annular plate portion 201 to the end section 23 on the upstream side of the housing 20 protrudes.

Provided on an outer circumference of the annular plate portion 201 is an edge section 202 which is formed over the entire outer circumference as a portion of the annular plate portion 201 is sublime. An outermost circumference of the edge section 102 can be in close contact with the inner peripheral surface 24 of the housing 20 be.

The element forming the flow path 200 has an extension wall 210 formed so as to coincide with the protruding portion 203 is consistent (so that they have a side wall 209 of the protruding section 203 is consistent). The extension wall 210 has the same height as the protruding section 203 and is provided so that it on the annular plate portion 201 between the protruding section 203 and the edge portion 202 stands.

The protruding section 203 has an upper section 205 a circular shape at one end of the protruding side of the protruding portion 203 is formed, and the upper section 205 has a bore formed therein 207 a circular shape. The hole 207 is consistent with a cutout section 208 which will be described later. An area covering the upper section 205 forms, extends to the extension wall 210 , Here is the top section 205 be designed so that it has an upper portion of the extension wall 210 includes.

The element forming the flow path 200 has the cutout portion formed therein 208 on. In this element forming the flow path 200 becomes one side of the cutout section 208 from the extension wall 210 certainly. For example, a section between the extension wall 210 and a section 208a as the cutting section 208 educated.

The element forming the flow path 200 is inside the case 20 mounted such that the exhaust gas passing through the communication passage 14 has flowed, directly on the extension wall 210 or on the neighborhood of the extension wall 210 meets (see 8C ). In such a state is the upper section 205 in close contact with the end section 23 the upstream side of the housing 20 , and an outer periphery of the edge portion 202 is in close contact with the inner peripheral surface 24 of the housing 20 ,

In this way, of the annular plate portion 201 , the edge section 202 , the protruding section 203 , the upper section 205 , the extension wall 210 and the end section 23 and the inner peripheral surface 24 of the housing 20 a space (flow path) is formed, through which the exhaust gas flows. In particular, the exhaust gas flows through the communication passage 14 in the case 20 and flows to the cutout section 208 such that it regulates the flow in one direction through the extension wall 210 almost a turn around the protruding section 203 power. Then, the exhaust gas flows to the downstream side (to the SCR 16 ).

(Modified Example 7)

9A to 9D are explanatory partial graphic representations of the exhaust gas purification device 1 in which the flow path forming element 220 a modified example is used.

9A is a graphical representation that is part of an appearance of the SCR unit 4 shows. 9B is a sectional view taken along a line IXB-IXB in 9A , 9C is a sectional view taken along a line IXC-IXC in 9A , 9D is a perspective view of the flow path forming element 220 ,

The element forming the flow path 220 is shaped ring-shaped, making it a groove 221 in a U-shape, which is concavely bent to the center of the circular shape. That the flow path forming element 220 has an edge portion at an outer edge thereof 222 on, which is formed outward over the entire edge.

Moreover, it is part of the element forming the flow path 220 cut out with a predetermined width to a cutout section 228 to build.

The thus configured the flow path forming element 220 is in the inflow chamber 22 arranged so that the cutout section 228 furthest from the outlet of the communication passage 14 is positioned remotely (see, for example 9C ). For example, this is the flow path forming element 220 arranged such that the cutout section 228 and the outlet of the communication passage 14 are positioned 180 ° in a circumferential direction across the center O opposite each other. For example, the edge portion 222 in close contact of the inner peripheral surface 24 of the housing 20 ,

In this way, from the groove 221 and the inner peripheral surface 24 of the housing 20 a space (flow path) is formed, through which the exhaust gas flows. In particular, the exhaust gas flows through the communication passage 14 in the case 20 , flows through a portion of the concave portion of the groove 221 to the cutout section 228 and then flows to the downstream side (to the SCR 16 ).

[Functions and Effects of the Present Invention]

Hereinafter, functions and effects of the present invention will be described with reference to FIG 10 and 11 explained.

10 is an explanatory graph that is a function of the exhaust gas purifier 1 of the present invention. Here will be an explanation of the example of the flow path forming element 100 given.

10 shows a state in which the flow path forming element 100 inside the case 20 is arranged. The communication passage 14 is with the case 20 connected, and the injector 26 for injecting the liquid reducing agent becomes the communication passage 14 provided. 10 also shows by arrows a flow of the liquid reducing agent (vaporized reducing agent) coming from the injection nozzle 26 is injected.

The following explanation in this document focuses on the flow of the vaporized reductant (hereinafter also simply referred to as the reductant). Needless to say, the explanation does not differ from the case where the flow of the exhaust gas containing reducing agent is different.

That of the injector 26 injected reducing agent first flows over the communication passage 14 in the case 20 , Then the reducing agent flows into the housing 20 has flowed through a flow path through the element forming the flow path 100 is formed (the flow path of the flow path forming element 100 and the housing 20 is formed) in the exhaust gas purification device 1 of the present invention. In particular, the reducing agent flows through the space that separates from the annular disc portion 101 , the edge section 102 , the protruding section 103 and the end section 23 and the inner peripheral surface 24 of the housing 20 is formed as described above.

At that time, the reducing agent hits the protruding portion 103 of the flow path forming element 100 and is so separated (spread) that it is around the protruding section 103 around, thereby allowing the reducing agent along a side wall 109 around the protruding section 103 to stream. Then the reducing agent finally reaches the cutout section 108 , That is, the reducing agent becomes the cutout portion 108 (a single opening) guided such that a flow direction of the reducing agent from an outer peripheral surface (curved surface) of the protruding portion 103 is changed, and such that the reductant is added from other directions after it is separated and passed over a plurality of (in this example two) ways.

The reducing agent that has flowed in such a way that it is around the protruding section 103 gets around, reaches a section and hits him where the cutout section 108 is arranged, and at the same time flows through the cut portion 108 to the downstream side, ie to the SCR 16 ,

Specifically, the reducing agent that has hit the portion at which the cutout portion flows 108 is arranged via different routes to the SCR 16 , For example, a part of the reducing agent enters an inside of the protruding portion 103 a (see also 1 ) and flows from a central portion of the protruding part 103 (Middle section of the flow path forming element 100 ) to the SCR 16 , For example, the reducing agent flows through the communication passage first 14 in the inflow chamber 22 has flown back to the communication passage 14 and then flows to the SCR 16 , For example, another part of the reducing agent flows from a widest part of the cutout portion 108 directly to the SCR 16 ,

Due to the configuration in which the protruding section 103 has an approximately cylindrical shape (that is, the inside of the protruding portion 103 has a cavity-like shape) and the bore 107 and the cutout section 108 are continuous with each other, the reducing agent, which is hit on the section, at which the cutout section 108 is placed, not only in the downstream space of the cut-out section 108 to flow, but also into the interior of the protruding section 103 , That is, it must be ensured a larger space in which the reducing agent can be dispersed. Consequently, dispersion and evaporation of the reducing agent are effectively facilitated.

The cutout section 108 corresponds to an example of a connection portion of the present invention. The cutout section 108 also corresponds to an example of an opening portion.

As described above, in the present invention, a path length of a portion where the reducing agent from the injector 26 injected to the SCR 16 longer by a length by which the reducing agent flows in such a way that it around the protruding portion 103 gets around. In particular, the reducing agent reaches the SCR 16 not directly after it from the injector 26 injected and into the housing 20 has flowed, but the reducing agent reaches the SCR 16 over the cutting section 108 of the flow path forming element 100 after flowing through the space (flow path) passing through the element forming the flow path 100 and the case 20 is formed. For example, due to the space (flow path) formed by the flow path forming element 100 and the case 20 is formed, ensuring more time and the longer path length, in which the exhaust gas is the SCR 16 reached.

In this way, the sufficient time and path length for the dispersion and evaporation of the reducing agent are guaranteed. Therefore, the reducing agent can be dispersed more uniformly in the exhaust gas, and a decomposing function is facilitated. This is possible with the SCR 16 to perform a more effective reduction treatment of the NO _x in the exhaust gas.

All that has to be done according to the present invention, in particular, is the flowpath-forming element 100 within the inflow chamber 22 to arrange, and thus the aforementioned effects can be obtained without any other structure of the exhaust gas purification device 1 will be changed.

Accordingly, the efficiency of the reduction treatment of NO _x in the exhaust gas can be improved without the size of the exhaust gas purifier 1 is changed (without the size of the exhaust gas purifier 1 is increased).

11 is a graphical representation, the effects of the exhaust gas purification device 1 of the present invention. 11 Fig. 12 is a graph showing the results of comparison of the effects between an example (Example (1)) in which the flow path forming member 100 of the present invention, and conventional examples (Examples (2) to (5)) in which the flow path forming member of the present invention is not provided. In particular 11 a graph showing results of comparison of masses of the evaporated ammonia (masses of gaseous ammonia) in the case where the reducing agent from the injection nozzle 26 is injected. An injection amount of the reducing agent is the same in all Examples (1) to (5).

In 11 the time (sec) is plotted on the abscissa axis and a lot of ammonia (the mass of vaporized ammonia) is plotted on the ordinate axis. The time 0 refers to a timing of the beginning of the injection of the reducing agent.

Examples (1) to (5) are respectively given as "420 mm", "310 mm", "300 mm", "290 mm" and "280 mm", each of which shows the path length from the position where the Reducing agent is injected, up to the SCR 16 (Length of a flow path through which the exhaust gas flows). Here, the path in each of the examples (1) to (5) is defined by a general rule, and the length of the defined path is defined as the path length.

In Example (1), the path length is 420 mm, which is a larger value than in the other examples (2) to (5). The reason for this is that the path length is increased by a length by which the exhaust gas flows through the space (flow path) of the flow path forming member 100 and the housing 20 is formed.

Regarding 11 it is firstly held that in all examples (1) to (5) the mass of the gaseous ammonia is increased immediately after the reducing agent has been injected. That is, after the injection of the reducing agent, the reducing agent is dispersed and vaporized to produce the gaseous ammonia.

In particular, in Examples (3) to (5), however, the mass of the gaseous ammonia is smaller in value than in Example (1) (and Example (2)). This indicates that especially in Examples (3) to (5), the mass (generation amount) of the gaseous ammonia is smaller than in Example (1). Moreover, it is considered that the dispersion of the reducing agent is insufficient. Alternatively, it is assumed that the reducing agent (mixed gas of the exhaust gas and the reducing agent) is the SCR 16 achieved before the reducing agent is sufficiently dispersed and vaporized, thereby causing insufficient production of the gaseous ammonia.

In Example (2), the mass (generation amount) of the gaseous ammonia is larger than in Examples (3) to (5), but it is still smaller than in Example (1). In addition, a decrease in the mass (production amount) of the gaseous ammonia is observed after a predetermined period of time. This also leads to the assumption in the example (2) that the dispersion of the reducing agent is insufficient or to the assumption that the reducing agent (mixed gas or the exhaust gas and the reducing agent) is the SCR 16 achieved before the reducing agent is sufficiently dispersed and evaporated, thereby causing insufficient generation of the gaseous ammonia.

On the other hand, in Example (1), the mass (generation amount) of the gaseous ammonia is larger and more stable than in Examples (2) to (5). This leads to the assumption that when the flow path forming element 100 is used, the reducing agent is sufficiently dispersed in the exhaust gas, thereby enabling the stabilization of the generation of the gaseous ammonia. Thus, it is believed that the effectiveness of the reduction treatment in the SCR 16 can be improved (or preserved).

[Functions and effects of modified examples]

Depending on a positional relationship of the exhaust gas purification device 1 With respect to a vehicle body (not shown), there may be some directions in which the exhaust gas is less easy around the protruding portion 103 of the flow path forming element 100 gets around, and there may be other directions in which the exhaust just around the protruding section 103 gets around. In this case, in the example of 2A to 2D if the exhaust gas that passes through the communication passage 14 in the case 20 has flowed to the protruding section 103 to the cutout section 108 a time difference can flow until the exhaust gas cuts out the cut-out section 108 attained, depending on the directions along which it has passed.

When a position of the cutout section 108 with respect to the outlet of the communication passage 14 as in modified example 1 ( 3A to 3C ) is properly changed in consideration of the aforementioned point, the occurrence of the aforementioned time difference can be prevented, and the adjustment of the dispersion of the reducing agent can be aimed at. In particular, when the time difference is taken into consideration and the path length R1 and the path length R2 are differentiated from each other by a length corresponding to the time difference, a period for which the exhaust gas from the outlet of the communication passage 14 to the cutout section 108 flows about constant, regardless of the path through which the exhaust gas flows. In this case, the effect of the impact of the exhaust gas on the cutout portion 108 be uniform, and the mixing of the exhaust gas and the reducing agent (uniform dispersion and evaporation of the reducing agent) can be carried out without being hindered.

In modified example 2 ( 4A to 4D ), since the protruding section 123 has a triangular shape, the length of the path through which the exhaust gas flows so as to be around the protruding portion 123 around, run longer than those in the example of 2A to 2D in which the protruding section 103 has a circular shape. For example, by allowing the patterns of the path (flow path) through which the exhaust gas flows to be more complicated, it is considered that a large number of path lengths are ensured. Thus, uniform dispersion and evaporation of the reducing agent can be further facilitated.

In modified example 3 ( 5A to 5D ), it is assumed that the exhaust gas passing through the communication passage 14 has flowed, is more easily separated (spread) right and left when it strikes the sidewall portion S1, in particular, because the sidewall portion S1, which is a portion to which the exhaust gas hits, passes through the communication passage 14 has flowed, an approximately vertical angle with respect to the annular plate portion 141 having. Thus, the flow of the reducing agent is also distributed Simplified, and it is expected that the reducing agent is dispersed more uniformly and evaporated.

In modified example 4 ( 6A to 6D ), since the puncture section 161 is provided, in particular, be expected that the exhaust gas through the piercing section 161 easier to the downstream side (to the SCR 16 ) flows. In this case, it may become possible to facilitate easier exhaust gas flow to the downstream side (to the SCR 16 ) while uniformly dispersing and evaporating the reducing agent by increasing the path length of the exhaust gas as described above with the protruding portion 103 etc. is facilitated.

A similar discussion applies to the modified example 5 ( 7A to 7D ). In modified example 5 is the cutout section 188 wider than the cutout section 108 educated. It is thus expected that the exhaust gas will be easier to the downstream side (to the SCR 16 ) flows. In particular, it may be possible to facilitate easier flow of the exhaust gas to the downstream side (to the SCR 16 ) while facilitating uniform dispersion and vaporization of the reducing agent by adjusting the path length of the exhaust gas as described above with the protruding portion 103 etc. is increased.

In modified example 6 ( 8A to 8D ) is the flow of exhaust gas through the extension wall 210 limited to one direction only. In particular, the exhaust gas passing through the communication passage 14 in the case 20 has flowed from the extension wall 210 prevented from flowing to a side where the extension wall 210 is provided, and only allows him to flow to a side on which the extension wall 210 is not provided. In this case, the path length of the exhaust gas can be maximized, and it is expected that the reducing agent is more uniformly dispersed and vaporized.

In modified example 7 ( 9A to 9D ), the exhaust gas flows into the groove 221 the U-shape and reach the cut-out section 228 , When the exhaust gas flows into such a U-shaped groove, it is expected that the resistance is lower than in the other example of the present invention. In particular, the flow of the exhaust gas through the U-shaped groove is easily controlled. For example, the flow of the exhaust gas becomes stable with respect to the directionality of the flow due to the U-shaped groove, resulting in that the exhaust gas easily becomes the cutout portion 228 to be led. Thus, the exhaust gas is expected to flow smoother (the SCR 16 achieved more smoothly).

Other Embodiments

Although the exhaust gas purification device 1 According to the present invention, the present invention is not limited to the aforementioned embodiments and can take various forms within the technical scope of the present invention.

In the aforementioned modified example 2, the protruding portion is 123 for example, shaped such that its outer edge has a triangular shape; however, the shape of the outer edge is not limited to the triangular shape but may have various polygonal shapes.

In the above-mentioned modified example 3, a configuration may be adopted in which the position of the center O _{1 is} eccentric so as to be centered O 'on an opposite side from the communication passage 14 located. In which direction the position of the center O _{1 is} eccentric is not limited. The direction of eccentricity can take other directions.

In the aforementioned modified examples 2 to 7, each element constituting the flow path may be rotated in a similar manner as in the modified example 1. In particular, the flow path forming member may be arranged such that the length of the path from the outlet of the communication passage 14 to the cutout portion along a circumference of the protruding portion of the flow path forming member is varied depending on the flow direction with respect to the protruding portion.

In the aforementioned embodiment and the respective modified examples, a part of the flow path forming member is cut out by a range of a predetermined angle for forming the cutout portion. A center position as a reference of the angle is not limited to the center position O 'of the flow path forming member and may be set to another position. Optionally, the cutout portion may be formed by cutting in a parallel manner a part of the flow path forming member. Optionally, the cutout portion may be formed to gradually narrow toward the outside.

Instead of the cutout section (without the cutout section), holes may be like the small holes 162 to be ordered. Such holes may be construed as an example of the opening portion of the present invention.

In the aforementioned embodiment, an area of the flow path forming member may be formed to be smooth. For example, the surface may be polished or coated. In this case, a configuration may be adopted in which at least portions defining the flow path for the exhaust gas (surfaces of the annular disc portion 101 , the edge section 102 and the protruding section 103 ) are formed so as to be smooth by polishing, coating or the like. It is believed that such a design allows the exhaust gas to flow smoothly.

Optionally, the area of the flow path forming member may be rough. In particular, the element forming the flow path may, for example, have projections and recesses formed on its surface. In this case, it is conceivable that at least the portions forming the flow path for the exhaust gas (the surfaces of the annular disc portion 101 , the edge section 102 and the protruding section 103 ) are rough. That is, it is conceivable that protrusions and depressions are formed on the portions constituting the flow path of the exhaust gas (the surfaces of the annular disc portion 101 , the edge section 102 and the protruding section 103 ). With such a configuration, it is considered that turbulent flow is formed on such rough surfaces, thereby facilitating dispersion and evaporation of the reducing agent.

Such as in 12A shown, the annular plate portion 101 a groove 301 a linear shape formed on its surface along a flow direction of the exhaust gas (so that they are approximately parallel to the edge portion in this example 102 is).

The protruding section 103 can a groove 303a a linear shape formed on its peripheral surface (an example of a guide surface) along the flow direction (along the outer circumference of the protruding portion 103 and so that in this example they are approximately parallel to the circular edge 104 is).

The groove 301 and the groove 303a can each be one or more (three in the example of 12A ). In one example, the groove 301 and the groove 303a on the surface of the annular disc portion 101 and on the outer peripheral surface of the protruding portion 103 each formed by press molding.

With the example of 12A is to be expected that the exhaust gas through the groove 301 and the groove 303a run smoothly (the SCR 16 can achieve more smoothly). A path each of the groove 301 and the groove 303a may be formed in any shape so that the flow of the exhaust gas forms a desired pattern. For example, the groove 303a be provided in a meandering manner in a height direction of the protruding portion, so that a meandering flow of the exhaust gas in the height direction of the protruding portion 103 at least in the vicinity of the outer peripheral surface of the protruding portion 103 is relieved. Moreover, the groove 301 be provided in a meandering manner, so that a meandering flow of the exhaust gas at least in the vicinity of the surface of the annular plate portion 101 is relieved. Such a groove can only on one of the two surfaces, the annular plate portion 101 or the outer peripheral surface of the protruding portion 103 , be provided.

Such a groove may be used in the exhaust gas purification device of the aforementioned embodiment or in any exhaust gas purification device of the modified examples 1 to 7.

Optionally, such as in 12B shown, the annular plate section 101 a bead-shaped section 301b linear shape formed on its surface along the flow direction of the exhaust gas (so that in this example it is approximately parallel to the edge portion 102 is). The bead-shaped section 301b has a shape in which portions, the hill-like from the surface of the annular plate portion 101 stand out, are consistent with each other, so that they are long and thin.

The protruding section 103 can be a bead-shaped section 303b a linear shape formed on its outer peripheral surface along the flow direction (along the outer circumference of the protruding portion 103 and so that in this example it is approximately parallel to the circular edge 104 is).

The bead-shaped section 301b and the bead-shaped section 303b can each be one or more than one (three in the example of 12B ).

In one example, the bead-shaped portion 301b and the bead-shaped section 303b on the surface of the annular disc portion 101 and on the outer peripheral surface of the protruding portion 103 each formed by press molding.

With the example of 12B is expected that the exhaust from the bulbous section 301b and the bead-shaped portion 303b run smoothly (the SCR 16 can achieve more smoothly).

A flow path of both the bead-shaped portion 301b as well as the bead-shaped section 303b may be formed in any shape so that the flow of the exhaust gas forms a desired pattern. Moreover, the bead-shaped portion can only on one of the surfaces of the annular plate portion 101 or the outer peripheral surface of the protruding portion 103 be formed.

Such a bead-shaped portion may be used in the exhaust gas purification device of the aforementioned embodiment or in any of the exhaust gas purification devices of the modified examples 1 to 7.

Optionally, such as in 13A shown, the annular plate portion 101 the groove 301 linear shape and the bead-shaped section 301b linear shape formed on its surface along the flow direction of the exhaust gas (so that they are approximately parallel to the edge portion in this example 102 are). Preferably, the groove 301 and the bead-shaped section 301b provided so that they are approximately parallel to each other. Moreover, the groove 301 a and the bead-shaped section 301b be provided alternately with each other.

The protruding section 103 can the groove 303a linear shape and the bead-shaped section 303b linear shape formed on its outer peripheral surface along the flow direction (along the outer periphery of the protruding portion 103 and so that they are roughly parallel to the bottom edge 104 in this example). Preferably, the groove 303a and the bead-shaped section 303b provided so that they are approximately parallel to each other. Moreover, the groove 303a and the bead-shaped section 303b be provided alternately with each other.

In one example, the grooves 301 and 303a and the bead-shaped sections 301b and 303b on the surface of the annular disc portion 101 and the outer peripheral surface of the protruding portion 103 each formed by press molding.

With the example of 13A It is expected that the exhaust will flow more smoothly from the groove 301 and the bead-shaped portion 301b ; and the groove 303a and the bead-shaped portion 303b can be conducted (the SCR 16 can achieve more smoothly).

The path of both the groove 301 , as well as the bead-shaped section 301b ; and the groove 303a and the bead-shaped portion 303b may be formed in any shape so that the flow of the exhaust gas forms a desired pattern. Moreover, the groove and the bead-shaped portion can also only at one, the surface of the annular plate portion 101 or the outer peripheral surface of the protruding portion 103 be formed.

Such a groove and a bead-shaped portion may be used in the exhaust gas purification device of the aforementioned embodiment or in any of the exhaust gas purification devices of the modified examples 1 to 7.

As in 13B shown, the flow path forming element 100 wing sections 310 and 311 have, which distribute the exhaust gas. In this case, it is preferable that the flow path forming member 100 is arranged such that the wing sections 310 and 311 the outlet of the communication passage 14 are facing.

The wing sections 310 and 311 are continuous with the edge section 102 at the continuous sections 310a respectively. 311 while at the boundary ends 310b respectively 311b from the edge portion 102 are spaced.

The boundary ends 310b and 311b are each formed by a cutout between the edge portion 102 and the wing sections 310 respectively. 311 is formed. The wing section 310 and the wing section 311 are each closer to the leaders 310c respectively. 311c slightly bent so that they are relative to the edge portion 102 extend inwards. In this way are between the edge section 102 and the boundary ends 310b , respectively 311b column 310d and 311d arranged.

Moreover, there is a gap 312 between the wing section 310 and the wing section 311 arranged. That is, the wing section 310 and the wing section 311 are from each other with the gap between them 312 spaced.

With the thus configured the flow path forming element 100 At least a portion of the exhaust gas passes through the communication passage 14 into the room inside the upstream chamber 22 (Inflow space) has flowed through the gap 312 and flows into the upstream room. The exhaust gas then becomes along the outer peripheral surface (guide surface) of the protruding portion 103 guided. The rest of the exhaust gas hits the wing sections 310 and 311 and can in the upstream space along the outer surfaces of the wing sections 310 and 311 stream.

In such an example, the exhaust gas may flow into the upstream space after it from the wing sections 310 and 311 has been separated. Thus, the dispersion of the exhaust gas can be facilitated and finally the dispersion and evaporation of the reducing agent can be further facilitated. Because the wing sections 310 and 311 As previously described, the exhaust gas flowing onto the wing sections may be slightly bent 310 and 311 moreover, be guided smoothly along the curved outer surfaces. This can be the inhibition of the flow of the exhaust gas at the wing sections 310 and 311 Reduce.

The wing section 310 can be present twice or more times, and the wing section 311 can also be present twice or more times. Optionally, only one, the wing section 310 or the wing section 311 be provided. Such wing portions may be used in the exhaust gas purification device of the aforementioned embodiment or in any of the exhaust gas purification devices of the modified examples 1 to 7.

As in 14 shown may be on an outer surface of the edge portion 102 an inserted element 302a be provided, which is an element between the outer surface and the inner surface 24 is inserted. Moreover, on the surface (upper surface) of the upper section 105 an inserted element 305 a, which is an element between the surface (upper surface) and the end portion 23 is inserted. In the present invention, the inserted elements 302a and 305a each an annular shape.

In a state in which the flow path forming element 100 in the inflow chamber 22 is arranged, the inserted element 302a in close contact with the inner peripheral surface 24 be, and the inserted element 305a can be in close contact with the end section 23 be. This enables the upstream space and the downstream space to be more reliably separated from each other. In particular, it can be prevented that the exhaust gas between the edge portion 102 and the inner peripheral surface 24 or between the top section 105 and the end section 23 licks to flow into the downstream room. That is, this makes it safer that the exhaust gas reaches the downstream space after flowing through the upstream space, and thus effects of the dispersion of the exhaust gas (and finally the dispersion and evaporation of the reducing agent in the exhaust gas) can be enhanced.

The inserted elements 302a and 305a can each be one or two, as in 14 shown.

In particular, the inserted elements 302a having different diameters on the outer surface of the edge portion 102 be provided. Moreover, the inserted elements 305a having different diameters at the surface (upper surface) of the upper portion 105 be provided.

The inserted elements 302a and 305a can each be three or more. This can further improve the sealing effect.

The inserted elements 302a and 305a For example, they can be made of metal. The inserted elements 302a and 305a may for example be formed from a mesh-shaped metal material.

Such a configuration in which the interposed member is provided may be employed in the exhaust gas purification device of the aforementioned embodiment or in any of the exhaust gas purification devices of the modified examples 1 to 7.

Here, the element forming the flow path in the inflow chamber 22 be fixed by welding (welding). A welding process (welding) can be spot welding. In this case, the inserted member may be provided as long as welding (welding) is performed properly. In contrast, a configuration in which the inserted member is not provided may be adopted as appropriate.

The design of the 12A . 12B or 13A and the design of the 13B or 14 can be combined with each other.

In the present embodiment, the space within the inflow chamber corresponds 22 an example of an inflow space of the present invention. The respective rooms, formed by the circular dish sections 101 . 121 . 141 and 201 ; the edge sections 102 . 122 . 142 and 202 ; the protruding sections 103 . 123 . 143 and 203 ; the upper sections 105 . 125 . 145 respectively. 205 ; the end section 23 and the inner peripheral surface 24 of the housing 20 3, 5 correspond to an example of an upstream room of the present invention. The space of the groove 221 and the inner peripheral surface 24 of the housing 20 is formed corresponds to an example of the upstream space. Every space within the protruding sections 103 . 123 . 143 and 203 corresponds to an example of the downstream room. The space in the middle portion of the flow path forming member 220 corresponds to an example of the downstream room. The cutting sections 108 . 128 . 148 . 188 . 208 and 228 correspond to an example of an opening portion of the present invention. The little holes 162 (or the puncture section 160 ) correspond to an example of the opening portion of the present invention. Each outer peripheral surface of the protruding portions 103 . 123 . 143 and 203 and the surface of the groove 221 correspond to an example of a guide surface.

Claims (15)

Exhaust gas purification device disposed in an exhaust passage of an internal combustion engine, the device comprising: a housing into which an exhaust gas flows; and a catalyst provided in the housing, the catalyst performing a reduction treatment of the exhaust gas by consuming a reducing agent supplied to the housing, wherein the exhaust gas purifier within the housing includes a flow path forming member disposed in a space extending from a position in which the reducing agent is supplied to a position where the catalyst is disposed, the flow path forming element forms a flow path for the exhaust gas in the room. The exhaust gas purification device according to claim 1, wherein the flow path forming member is configured to block in the space a part of a path extending from the position where the reducing agent is supplied to the position where the catalyst is arranged.  The exhaust gas purification device according to claim 1 or 2, wherein the flow path forming member includes a protruding portion that separates a flow of the exhaust gas.  The exhaust gas purifying apparatus according to claim 3, wherein the flow path forming member is configured to form a connecting portion to which the exhaust gas which has flowed out separately is added.  Exhaust gas purification device, comprising: a catalyst; a housing including the catalyst, the housing forming an outflow path for allowing an exhaust gas that has entered to pass through the catalyst and then being discharged; and a flow path-forming member that separates an inflow space into an upstream space and a downstream space, the inflow space being a space formed upstream of the catalyst within the housing and into which the exhaust gas is to be supplied thereto through the catalyst to arrive, flows, wherein the flow path forming member comprises: at least one opening portion that allows the communication between the upstream space and the downstream space, the at least one opening portion forming a passage through which the exhaust gas that has flowed into the upstream space flows to the downstream space; and a guide surface that guides the exhaust gas that has flowed into the upstream space to the opening portion, such that a flow direction of the exhaust gas is changed.  The exhaust gas purification device according to claim 5, wherein the guide surface guides the exhaust gas that has flowed into the upstream space to the opening portion, so that the exhaust gas is separated and guided through a plurality of paths.  The exhaust gas purification device according to claim 6, wherein the guide surface guides the exhaust gas that has been separated to the opening portion as a single opening.  The exhaust gas purification device according to claim 6 or 7, wherein the guide surface allows the exhaust gas which has been separated to be added from different directions.  The exhaust gas purification device according to any one of claims 6 to 8, wherein the guide surface has a groove formed thereon, which is continuous from a side where the exhaust gas flows to a side at which the opening portion is provided.  The exhaust gas purification device according to any one of claims 6 to 9, wherein the guide surface has a bead-shaped portion formed thereon protruding from the guide surface, the bead-shaped portion being long and thin from the side where the exhaust gas flows Side on which the opening portion is provided. The exhaust gas purification device according to any one of claims 5 to 10, wherein the flow path forming member is provided such that a wall portion that separates the upstream space and the downstream space is not positioned on a center axis of the catalyst.  The exhaust gas purification device according to any one of claims 5 to 11, wherein the downstream space is shaped to be larger toward the catalyst.  Exhaust gas purification device according to one of claims 5 to 12, wherein the flow path forming member comprises: an annular cup portion arranged to face an outer peripheral portion of an inflow surface of the catalyst; and a protruding portion of a cylindrical shape protruding from an inner edge of the annular cup portion to an opposite side from the catalyst, wherein the inflow space is divided by the annular plate portion and the protruding portion into the upstream space and the downstream space, wherein at least a part of an outer peripheral surface of the protruding portion serves as a guide surface, and wherein the opening portion is provided in at least one of the annular cup portion and the protruding portion.  The exhaust gas purifying apparatus according to claim 13, wherein the protruding portion has a shape gradually narrowing toward a front end of the protruding portion.  The exhaust gas purification device according to claim 13 or 14, wherein the annular cup portion and the protruding portion of the flow path forming member are integrally formed.

Images