WO2010053033A1

WO2010053033A1 - Exhaust purifying device for internal combustion engine

Info

Publication number: WO2010053033A1
Application number: PCT/JP2009/068543
Authority: WO
Inventors: 井上三樹男; 辻本健一
Original assignee: トヨタ自動車株式会社
Priority date: 2008-11-05
Filing date: 2009-10-22
Publication date: 2010-05-14
Also published as: EP2343440A4; CN102187070A; JPWO2010053033A1; US20110225958A1; JP5104960B2; EP2343440A1

Abstract

An exhaust purifying device for an internal combustion engine is provided with an exhaust manifold (19), a catalytic converter (21) provided at an angle to the exhaust manifold (19) at a position downstream of the exhaust manifold (19) and incorporating a NOx occluding and reducing catalyst (20), and a reducing agent supply device (22) for supplying a reducing agent to exhaust gas passing through the inside of the exhaust manifold. A projection (35) projecting outward radially of a casing (30) of the catalytic converter is provided to the inner wall surface of the casing (30) at a position facing the exit of the exhaust manifold. That portion of the wall surface which defines the projection is formed in such a manner that the component, in the direction of the axis of the casing, of the speed of the flow of at least a portion of the exhaust gas flowing into the projection is oriented by the projection in the direction opposite the direction toward the NOx occluding and reducing catalyst. The exhaust purifying device can minimize an increase in loss of pressure of the exhaust gas and can disperse the reducing agent, which is supplied from the reducing agent supply device, into the exhaust gas.

Description

Exhaust gas purification device for internal combustion engine

The present invention relates to an exhaust purification device for an internal combustion engine.

The exhaust gas discharged from the internal combustion engine contains nitrogen oxides (NO _x ) and particulate matter such as soot, and various measures are taken to purify these components. In one of such configurations, a catalyst or particulate filter having a NO _X storage reduction function (hereinafter referred to as “NO _X storage reduction catalyst”) is provided in the engine exhaust passage, and the engine is disposed upstream of the exhaust of the catalyst. An exhaust emission control device provided with a reducing agent supply device for supplying a reducing agent into the exhaust passage may be mentioned.
In such an exhaust purification device supplies reducing agent in the engine exhaust passage from the reducing agent supply device when it is much _the NO _X storage amount to _the NO _X storage reduction catalyst, leaving the NO _X from _the NO _X storage reduction catalyst In addition, NO _X is reduced and purified.
Here, when supplying reducing agent from the reducing agent supply device, a withdrawal and reduction of the NO _X in _the NO _X storage reduction catalyst in order to optimally performed to the entire NO _X storage reduction catalyst the supplied reducing agent It is necessary to uniformly flow into the NO _X storage reduction catalyst. For this reason, various techniques have been proposed to uniformly diffuse the supplied reducing agent into the exhaust gas flowing in the engine exhaust passage.
For example, in the exhaust gas purification device disclosed in Patent Document 1, a throttle portion that reduces the cross-sectional area of the exhaust flow is provided in the exhaust pipe between the reducing agent supply device and the exhaust gas purification catalyst. In this exhaust purification device, the flow of the exhaust gas is accelerated by the throttle portion to generate a disturbance in the exhaust gas, thereby diffusing the reducing agent supplied from the reducing agent supply device.
Further, in the exhaust purification device disclosed in Patent Document 2, an exhaust introduction pipe having a closed end and having a plurality of perforations and a partition wall having a plurality of perforations are provided in the catalytic converter upstream of the exhaust purification catalyst. Is provided. Furthermore, in the exhaust gas purification device disclosed in Patent Document 3, a plurality of diffusion plates arranged alternately are provided in the exhaust pipe between the reducing agent supply device and the exhaust gas purification catalyst. In these exhaust purification apparatuses, the exhaust gas is disturbed by the exhaust introduction pipe, the partition wall, and the diffusion plate, so that the reducing agent supplied from the reducing agent supply device is diffused in the exhaust gas.

JP 2002-213233 A JP 2003-184544 A JP 2005-325747 A

By the way, the throttling portion, the exhaust introduction pipe, the partition wall, and the diffusion plate used in the exhaust gas purification devices described in Patent Documents 1 to 3 all disturb the exhaust gas by disturbing the flow of the exhaust gas. I am letting. For this reason, by providing these components in the engine exhaust passage, the reducing agent can be diffused into the exhaust gas, but the pressure loss of the exhaust gas increases accordingly. When the pressure loss of the exhaust gas increases in this way, the exhaust gas hardly flows out from the combustion chamber of the internal combustion engine, and as a result, there is a risk of causing a decrease in engine output, a deterioration in fuel consumption, and the like.
Accordingly, an object of the present invention is to provide an exhaust purification device for an internal combustion engine capable of diffusing the reducing agent supplied from the reducing agent supply device into the exhaust gas while suppressing an increase in the pressure loss of the exhaust gas. It is in.

The present invention provides, as means for solving the above problems, a control device for an internal combustion engine described in each claim.
In a first aspect of the present invention, an upstream exhaust passage through which exhaust gas discharged from an internal combustion engine flows, and a downstream disposed at an angle with respect to the upstream exhaust passage downstream of the upstream exhaust passage. An exhaust purification device for an internal combustion engine, comprising: a side exhaust passage, a reducing agent supply means for supplying a reducing agent into the exhaust gas passing through the upstream exhaust passage, and an exhaust purification means provided in the downstream exhaust passage A flow deflecting portion is provided on a portion of the inner wall surface defining the downstream exhaust passage facing the upstream exhaust passage outlet, the flow deflecting portion being located upstream of the exhaust purification means, It is formed to direct the velocity component in the downstream exhaust passage axial direction of the flow of at least part of the exhaust gas flowing into the flow deflecting portion in the direction opposite to the direction toward the exhaust purification means.
According to this aspect, the exhaust gas directed in the direction opposite to the direction toward the exhaust gas purification means by the flow deflector formed on the inner wall surface collides with another exhaust gas. Due to such a collision, the exhaust gas is disturbed, and the mixing of the reducing agent and the exhaust gas is promoted. Further, since the flow deflector only changes the direction of the exhaust gas flow, there is substantially no component that serves as a throttle for the exhaust gas flow, and the pressure loss of the exhaust gas hardly increases.
Therefore, according to this aspect, it is possible to promote the mixing of the reducing agent and the exhaust gas by causing disturbance in the exhaust gas. Moreover, the component which becomes a restriction | limiting with respect to the flow of exhaust gas is not provided substantially. For this reason, it is possible to diffuse the reducing agent supplied from the reducing agent supply device into the exhaust gas while suppressing an increase in the pressure loss of the exhaust gas.
In the second aspect of the present invention, the region on the exhaust purification means side of the wall surface defining the flow deflection section is inclined in the direction opposite to the direction toward the exhaust purification means toward the radially outer side of the downstream exhaust passage. Has a part.
In the third aspect of the present invention, an upstream exhaust passage through which exhaust gas discharged from the internal combustion engine flows, and a downstream disposed at an angle with respect to the upstream exhaust passage on the downstream side of the upstream exhaust passage. An exhaust purification device for an internal combustion engine, comprising: a side exhaust passage, a reducing agent supply means for supplying a reducing agent into the exhaust gas passing through the upstream exhaust passage, and an exhaust purification means provided in the downstream exhaust passage , A flow deflecting portion is provided in a portion of the inner wall surface defining the downstream exhaust passage facing the upstream exhaust passage outlet, and the flow deflecting portion is located upstream of the exhaust purification means, The wall surface of the flow section hits a part of the wall surface of the flow deflecting unit, and at least a part of the exhaust gas whose velocity component in the direction toward the exhaust purification means is increased hits the other part of the wall surface of the flow deflecting unit, Gas velocity component in the same direction It is formed so as to be allowed to decrease.
According to this aspect, the exhaust gas whose velocity component in the direction toward the exhaust gas purification unit is increased by a part of the wall surface of the flow deflection unit hits the other part of the wall surface of the flow deflection unit. The speed component in the direction toward the purification means is reduced. In this way, the collision with the other part of the wall surface such that the velocity component in the direction toward the exhaust gas purification means decreases, so that the exhaust gas is disturbed and the mixing of the reducing agent and the exhaust gas is promoted. Further, since the flow deflector only changes the direction of the exhaust gas flow, there is substantially no component that serves as a throttle for the exhaust gas flow, and the pressure loss of the exhaust gas hardly increases.
Therefore, according to this aspect, it is possible to promote the mixing of the reducing agent and the exhaust gas by causing disturbance in the exhaust gas. Moreover, the component which becomes a restriction | limiting with respect to the flow of exhaust gas is not provided substantially. For this reason, it is possible to diffuse the reducing agent supplied from the reducing agent supply device into the exhaust gas while suppressing an increase in the pressure loss of the exhaust gas.
In the fourth aspect of the present invention, the region of the wall surface defining the flow deflection portion on the side away from the exhaust purification means is a portion inclined in the direction toward the exhaust purification means toward the radially outer side of the downstream exhaust passage. Have
In the fifth aspect of the present invention, the flow deflection section includes a protruding portion formed such that the inner wall surface itself defining the downstream exhaust passage protrudes radially outward of the downstream exhaust passage.
According to this aspect, even if the reducing agent supplied from the reducing agent supply means is not sufficiently vaporized and flows out from the upstream exhaust passage in the form of droplets, the droplets are received and evaporated in the protrusions. Therefore, it is possible to suppress the reducing agent from flowing into the exhaust purification means in the form of droplets and adhering thereto.
In a sixth aspect of the present invention, the cross section of the projecting portion in the downstream exhaust passage circumferential direction is substantially semi-elliptical.
In a seventh aspect of the present invention, the inlet area of the protruding portion facing the downstream exhaust passage is larger than the cross-sectional area of the upstream exhaust passage.
In the eighth aspect of the present invention, the height of the protruding portion in the axial direction of the downstream exhaust passage is larger than the diameter of the upstream exhaust passage.
In the ninth aspect of the present invention, the protrusion extends in the circumferential direction of the downstream exhaust passage.
In the tenth aspect of the present invention, the depth of the protruding portion in the radial direction of the downstream exhaust passage decreases as the distance from the region facing the upstream exhaust passage outlet increases.
In the eleventh aspect of the present invention, the protrusion is formed so that its outer periphery is substantially semi-elliptical.
In a twelfth aspect of the present invention, the protruding portion is inclined so as to be positioned closer to the exhaust purification means as it moves away from the region facing the upstream exhaust passage outlet in the circumferential direction of the downstream exhaust passage.
In the thirteenth aspect of the present invention, the upstream exhaust passage extends in the vicinity of its outlet so that its central axis passes through the protrusion.
In the fourteenth aspect of the present invention, the upstream exhaust passage extends in an inclined manner with respect to the central axis of the downstream exhaust passage in the vicinity of the outlet thereof.
In the fifteenth aspect of the present invention, the upstream exhaust passage extends perpendicularly to the central axis of the downstream exhaust passage in the vicinity of the outlet thereof.
In the sixteenth aspect of the present invention, the upstream exhaust passage extends into the downstream exhaust passage.
In the seventeenth aspect of the present invention, the upstream side exhaust passage outlet is made to enter the protrusion.
In an eighteenth aspect of the present invention, the flow deflector includes a protrusion formed by an inner wall surface itself defining the downstream exhaust passage projecting radially outward of the downstream exhaust passage, A cross section in the circumferential direction of the downstream side exhaust passage of the protrusion is substantially rectangular.
In a nineteenth aspect of the present invention, the flow deflector includes a protrusion protruding from the inner wall surface defining the downstream exhaust passage toward the radially inner side of the downstream exhaust passage.
In a twentieth aspect of the present invention, the upstream exhaust passage is defined by an exhaust manifold or an exhaust pipe directly connected to the exhaust manifold, and the downstream exhaust passage is formed in an upstream portion of a catalytic converter that houses exhaust purification means. It is the cone part provided.
Hereinafter, the present invention will be more fully understood from the accompanying drawings and the description of preferred embodiments of the present invention.

FIG. 1 is a diagram schematically showing an entire internal combustion engine in which an exhaust emission control device of the present invention is mounted.
2A and 2B are enlarged views of the catalytic converter of the first embodiment shown in FIG.
3A and 3B are enlarged views of the catalytic converter of the second embodiment.
4A and 4B are enlarged views of the catalytic converter of the third embodiment.
5A and 5B are enlarged views of the catalytic converter of the fourth embodiment.
6A and 6B are enlarged views of the catalytic converter of the fifth embodiment.
7A and 7B are enlarged views of the catalytic converter of the sixth embodiment.
8A and 8B are enlarged views of the catalytic converter of the seventh embodiment.
9A and 9B are enlarged views of the catalytic converter of the eighth embodiment.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In the following description, the same reference numerals are assigned to similar components.
FIG. 1 is a diagram schematically showing an entire internal combustion engine in which an exhaust emission control device of the present invention is mounted. Referring to FIG. 1, 1 is an engine body, 2 is a cylinder block, 3 is a piston that reciprocates in the cylinder block 2, 4 is a cylinder head fixed on the cylinder block 2, and 5 is a piston 3 and a cylinder head 4. A combustion chamber formed therebetween, 6 is an intake valve, 7 is an intake port, 8 is an exhaust valve, and 9 is an exhaust port. As shown in FIG. 1, a spark plug 10 is arranged at the center of the inner wall surface of the cylinder head 4, and a fuel injection valve 11 is arranged around the inner wall surface of the cylinder head 4. A cavity 12 extending from the lower side of the fuel injection valve 11 to the lower side of the spark plug 10 is formed on the top surface of the piston 3.
The intake port 7 of each cylinder is connected to a surge tank 14 via a corresponding intake branch pipe 13, and the surge tank 14 is connected to an air cleaner (not shown) via an intake duct 15 and an air flow meter 16. A throttle valve 18 driven by a step motor 17 is disposed in the intake duct 15. On the other hand, the exhaust port 9 of each cylinder is connected to an exhaust manifold 19, and this exhaust manifold 19 is NO. _X It is connected to a catalytic converter 21 containing a storage reduction catalyst 20. In the present embodiment, NO in the catalytic converter 21 _X Although the occlusion reduction catalyst 20 is incorporated, any exhaust purification means may be incorporated as long as it requires the supply of a reducing agent for purification of exhaust gas. Examples of such exhaust purification means include an oxidation catalyst, a three-way catalyst, a particulate filter, and the like.
The exhaust manifold 19 is provided with a reducing agent supply device 22 that supplies a reducing agent into the exhaust gas flowing through the exhaust manifold 19. The exhaust manifold 19 and the surge tank 14 are connected to each other via a recirculated exhaust gas (hereinafter referred to as EGR gas) conduit 26, and an EGR gas control valve 27 is disposed in the EGR gas conduit 26.
2A and 2B are enlarged views of the catalytic converter 21 shown in FIG. 2A is a sectional side view as seen from line A in FIG. 2B, and FIG. 2B is a sectional plan view as seen from line B in FIG. 2A. As shown in FIGS. 2A and 2B, the catalytic converter 21 includes a casing 30, and NO inside the casing 30 is NO. _X The storage reduction catalyst 20 is accommodated. The casing 30 is NO _X A catalyst housing part 31 for housing the storage reduction catalyst 20 and a cone part 32 provided on the exhaust upstream side of the catalyst housing part 31 are provided. Each of the catalyst housing portion 31 and the cone portion 32 of the casing 30 defines an exhaust passage (downstream exhaust passage) through which exhaust gas flows.
In this embodiment, NO _X The occlusion reduction catalyst 20 and the casing 30 (catalyst accommodating portion 31 and cone portion 32) are arranged coaxially, and their axis L extends substantially vertically. Therefore, the exhaust passage defined by the casing 30 (that is, the catalyst housing portion 31 and the cone portion 32) also extends substantially vertically. In the following description, NO _X The description will be made with the exhaust upstream side of the storage reduction catalyst 20 as the upper side and the exhaust downstream side as the lower side. NO _X The axis L of the storage reduction catalyst 20 and the casing 30 does not necessarily extend substantially vertically, and may be arranged to extend in any direction such as horizontal. NO _X The occlusion reduction catalyst 20 and the casing 30 are not necessarily arranged coaxially.
As shown in FIGS. 2A and 2B, the exhaust manifold 19 is connected to the casing 30. Specifically, the exhaust manifold 19 extends through the wall surface of the cone portion 32 in the upper portion of the cone portion 32 of the casing 30. Accordingly, the exhaust manifold 19 enters the cone portion 32. As shown in FIGS. 2A and 2B, the exhaust manifold 19 is inclined with respect to the axis L at a location that penetrates the wall surface of the cone portion 32. Further, the exhaust manifold 19 is arranged so that a portion near the outlet of the exhaust manifold 19 (hereinafter referred to as “manifold outlet vicinity”) 19a extends perpendicular to the axis L, that is, perpendicular to the wall surface of the cone portion 32. It curves in the cone part 32 so that it may extend. As shown in FIGS. 2A and 2B, the outlet of the exhaust manifold 19 faces a part of the inner wall surface of the cone portion 32. The exhaust manifold 19 configured as described above defines an exhaust passage (upstream exhaust passage) through which exhaust gas discharged from the engine body 1 flows.
A protruding portion 35 protruding in the radial direction of the casing 30 is provided on a portion of the inner wall surface of the cone portion 32 that faces the outlet of the exhaust manifold 19. As shown in the side sectional view of FIG. 2A, the upper wall surface 35 a of the protruding portion 35 is inclined downward toward the radially outer side of the casing 30, and the lower wall surface 35 b of the protruding portion 35 is the radial direction of the casing 30. Inclined upward toward the outside. In particular, in this embodiment, the cross section of the protrusion 35 in the circumferential direction of the casing 30 is substantially semi-elliptical.
Further, as shown in FIG. 2B, the projecting portion 35 extends from the region facing the outlet of the exhaust manifold 19 toward both sides in the circumferential direction of the casing 30. When the length from the inner wall surface of the cone portion 32 to the portion of the protruding portion that protrudes most in the radial direction of the casing 30 when the protruding portion 35 is not present is the depth D of the protruding portion 35, the depth D of the protruding portion 35 is As the distance from the region facing the outlet of the exhaust manifold 19 increases in the circumferential direction of the casing 30, the depth becomes shallower. That is, the depth D of the protrusion 35 is the deepest in the region facing the outlet of the exhaust manifold 19 and becomes shallower as it extends in the circumferential direction from here. In particular, as shown in FIG. 2B, in the present embodiment, the outer periphery of the protruding portion 35 is formed to have a substantially semi-elliptical shape. Further, in the present embodiment, the protruding portion 35 extends over a half circumference in the circumferential direction of the casing 30.
The flow of the exhaust gas in the exhaust manifold 19 and the casing 30 configured as described above will be described. The arrows in FIGS. 2A and 2B indicate the flow of exhaust gas. In the exhaust manifold 19, exhaust gas discharged from the engine body 1 and supplied with a reducing agent by the reducing agent supply device 22 flows. Therefore, the exhaust gas flowing in the exhaust manifold 19 of FIGS. 2A and 2B contains a reducing agent that is not sufficiently mixed with the exhaust gas.
The exhaust gas containing the reducing agent that has flowed through the exhaust manifold 19 flows out from the outlet of the exhaust manifold 19 and flows into the protrusion 35. The exhaust gas flowing in the lower part of the manifold outlet vicinity 19 a collides with the lower wall surface 35 b of the protrusion 35. Due to this collision, the flow direction of the exhaust gas is directed upward. On the other hand, the exhaust gas flowing through the upper part of the manifold outlet vicinity 19 a collides with the upper wall surface 35 a of the protrusion 35. This collision causes the exhaust gas to flow downward.
Thus, when the exhaust gas colliding with the lower wall surface 35b of the projection 35 is directed upward, the exhaust gas colliding with the upper wall surface 35a of the projection 35 is directed downward. Will collide with each other. In this way, the exhaust gas is agitated by the collision of the two exhaust gases, thereby promoting the mixing of the reducing agent contained in the exhaust gas and the exhaust gas.
Further, the exhaust gas that collides with the lower wall surface 35b of the protrusion 35 and whose flow direction is directed upward collides with the exhaust gas that collides with the upper wall surface 35a of the protrusion 35 and whose flow direction is directed downward. Even if not, it collides with the upper wall surface 35a of the protrusion 35. Due to the collision with the upper wall surface 35a, the upward velocity component of the exhaust gas is reduced and the exhaust gas is agitated accordingly, and the mixing of the reducing agent and the exhaust gas contained in the exhaust gas is promoted. The
Similarly, the exhaust gas that collides with the upper wall surface 35a of the projecting portion 35 and whose flow direction is directed downward collides with the exhaust gas that collides with the lower wall surface 35b of the projecting portion 35 and has the flow direction directed upward. Even if it does not, it collides with the lower side wall surface 35b of the protrusion 35. Due to the collision with the lower wall surface 35b, the downward velocity component of the exhaust gas is reduced, and the exhaust gas is stirred accordingly, and the mixing of the reducing agent contained in the exhaust gas and the exhaust gas is promoted. Is done.
The exhaust gas that has flowed into the protrusion 35 collides with the wall surface of the protrusion 35 to change the direction of the flow in the vertical direction, and as indicated by an arrow in FIG. 2B, the exhaust gas flows along the wall surface of the protrusion 35. It flows toward both sides in the circumferential direction. As a result, the exhaust gas flowing into the projecting portion 35 spreads uniformly throughout the casing 30. For this reason, the exhaust gas in which the reducing agent is uniformly mixed is NO. _X It will flow uniformly into the storage reduction catalyst 20. Therefore, NO _X In the storage reduction catalyst 20, the reaction with the reducing agent is NO. _X Performed uniformly over the entire storage reduction catalyst 20, for example, NO _X NO stored in the storage reduction catalyst 20 _X The purification is optimally performed.
Here, according to the exhaust manifold 19 and the casing 30 of the present embodiment, in order to promote the mixing of the reducing agent contained in the exhaust gas and the exhaust gas, a member that restricts the flow area of the exhaust gas is provided. Not. For this reason, even if the exhaust gas flows through the exhaust manifold 19 and the casing 30 having the above-described configuration, almost no pressure loss occurs. Therefore, according to the embodiment of the present invention, it is possible to promote the mixing of the reducing agent and the exhaust gas contained in the exhaust gas with almost no pressure loss of the exhaust gas.
Further, the reducing agent in the exhaust gas flowing through the exhaust manifold 19 is not sufficiently vaporized at the outlet of the exhaust manifold 19 and may flow out of the exhaust manifold 19 in the form of droplets. However, in the exhaust manifold 19 and the casing 30 of the present embodiment, even if the reducing agent flows out of the exhaust manifold 19 in the form of droplets, most of it flows into the protruding portion 35. Furthermore, the droplets that have flowed into the protruding portion 35 are likely to evaporate due to the turbulence of the exhaust gas generated in the protruding portion 35. For this reason, even when the reducing agent flows out of the exhaust manifold 19 in the form of droplets, the reducing agent remains in the state of droplets as NO. _X Inflow and adhesion to the storage reduction catalyst 20 are suppressed.
In the above-described embodiment, the protrusion 35 extends from the region facing the outlet of the exhaust manifold 19 by substantially the same length on both sides in the circumferential direction. However, the protrusions 35 do not necessarily extend the same length on both sides in the circumferential direction, and may be configured such that one side extends longer than the other side.
Further, in the above embodiment, the protrusion 35 extends in the circumferential direction, that is, on a plane perpendicular to the axis L, from the region facing the outlet of the exhaust manifold 19. However, the projecting portion 35 may be configured to be inclined with respect to the circumferential direction, that is, to be inclined with respect to a plane perpendicular to the axis L. For example, the projecting portion 35 may be inclined so as to be positioned on the lower side as the distance from the region facing the outlet of the exhaust manifold 19 increases in the circumferential direction.
Next, a second embodiment of the present invention will be described with reference to FIGS. 3A and 3B. 3A and 3B are enlarged views similar to FIGS. 2A and 2B of the catalytic converter 21 of the second embodiment. The configuration of the exhaust purification device of the second embodiment is basically the same as the configuration of the exhaust purification device of the first embodiment. However, in the exhaust purification device of the first embodiment, the cross section of the protrusion 35 in the circumferential direction of the casing 30 is substantially semi-elliptical, whereas in the exhaust purification device of the second embodiment, the circumferential direction of the casing 30 The cross section of the protrusion 40 in FIG.
As shown in FIG. 3A, the protrusion 40 includes a vertical wall surface 40a extending parallel to the axis L, an upper horizontal wall surface 40b connected to an upper portion of the vertical wall surface 40a and extending perpendicularly to the axis L, and a vertical wall surface 40a. A lower horizontal wall surface 40c connected to the lower portion and extending perpendicularly to the axis L is provided.
The flow of the exhaust gas in the exhaust manifold 19 and the casing 30 configured as described above will be described. The exhaust gas containing the reducing agent that has flowed through the exhaust manifold 19 flows out from the outlet of the exhaust manifold 19 and flows into the protrusion 40. Since the lower horizontal wall surface 40c of the protrusion 40 extends substantially parallel to the manifold outlet vicinity 19a, the exhaust gas flowing below the manifold outlet vicinity 19a hardly collides with the lower horizontal wall 40c of the protrusion 40. Still, some of them have a downward velocity component and thus collide with the lower horizontal wall surface 40c. Due to this collision, the flow direction of the exhaust gas is upward, and the exhaust gas collides with the exhaust gas flowing into the protrusion 40 from the exhaust manifold 19.
On the other hand, since the upper horizontal wall surface 40b of the protrusion 40 also extends substantially parallel to the manifold outlet vicinity portion 19a, the exhaust gas flowing above the manifold outlet vicinity portion 19a hardly collides with the upper horizontal wall surface 40b of the protrusion portion 40. However, some of them still have upward velocity components, and thus collide with the upper horizontal wall surface 40b. By this collision, the flow direction of the exhaust gas is directed downward, and the exhaust gas collides with the exhaust gas flowing into the protrusion 40 from the exhaust manifold 19.
As the exhaust gases collide with each other in this way, the exhaust gas is agitated, thereby promoting the mixing of the reducing agent and the exhaust gas contained in the exhaust gas. Also, in this embodiment, there is no member that restricts the cross-sectional area of the exhaust gas, so that the reducing agent and exhaust contained in the exhaust gas hardly increase the pressure loss of the exhaust gas. Mixing with gas can be promoted.
Further, as described above, a part of the exhaust gas that collides with the lower horizontal wall surface 40c of the protrusion 40 and whose flow direction is directed upward collides with the upper horizontal wall surface 40b of the protrusion 40. Due to the collision with the upper horizontal wall surface 40b, the upward velocity component of the exhaust gas is reduced, and the exhaust gas is agitated accordingly, and the mixing of the reducing agent and the exhaust gas contained in the exhaust gas is promoted. Is done. Furthermore, a part of the exhaust gas that collides with the upper horizontal wall surface 40 b of the protruding portion 40 and whose flow direction is directed downward collides with the lower horizontal wall surface 40 c of the protruding portion 40. Due to the collision with the lower horizontal wall surface 40c, the downward velocity component of the exhaust gas is reduced, and the exhaust gas is stirred accordingly, and the mixing of the reducing agent and the exhaust gas contained in the exhaust gas is promoted. Is done.
Next, a third embodiment of the present invention will be described with reference to FIGS. 4A and 4B. 4A and 4B are enlarged views similar to FIGS. 2A and 2B of the catalytic converter 21 of the third embodiment. The configuration of the exhaust purification device of the third embodiment is basically the same as the configuration of the exhaust purification device of the first embodiment. However, in the exhaust purification apparatus of the second embodiment, the cross section of the protrusion 35 in the circumferential direction of the casing 30 is substantially semi-elliptical, whereas in the exhaust purification apparatus of the third embodiment, the circumferential direction of the casing 30 The cross section of the protrusion 45 is substantially circular.
As shown in FIG. 4A, the protruding portion 45 is temporarily inclined upward toward the radially outer side of the casing 30 and then upwardly inclined downward, and once toward the radially outer side of the casing 30. A lower wall surface 45b inclined downward and then upward.
The flow of the exhaust gas in the exhaust manifold 19 and the casing 30 configured as described above will be described. The exhaust gas containing the reducing agent that has flowed through the exhaust manifold 19 flows out from the outlet of the exhaust manifold 19 and flows into the protrusion 45. Since the lower wall surface 45b of the protrusion 45 is inclined downward and then upward, when the exhaust gas flowing through the lower portion of the manifold outlet vicinity 19a flows into the protrusion 45, first, the lower wall surface 45b. It flows along the part inclined downward. Then, it collides with a portion inclined above the lower wall surface 45b of the protrusion 45. Due to this collision, the flow direction of the exhaust gas is directed upward.
On the other hand, since the upper wall surface 45a of the projecting portion 45 is once inclined upward and then downward, when the exhaust gas flowing through the upper portion of the manifold outlet vicinity portion 19a flows into the projecting portion 45, first, the upper wall surface 45a. It flows along a portion inclined upward. Then, it collides with a portion inclined downward of the upper plane 45a of the protrusion 45. This collision causes the exhaust gas to flow downward.
Thereafter, the exhaust gas that collides with the lower wall surface 45b of the protrusion 45 and flows upward and the exhaust gas that collides with the upper wall surface 45a of the protrusion 45 and flows downward collide with each other, and are thus included in the exhaust gas. Mixing of the reducing agent and the exhaust gas is promoted.
Further, the exhaust gas that collides with the portion inclined upward of the lower wall surface 45b of the protrusion 45 and flows upward is collided with the portion inclined downward of the upper wall surface 45a of the protrusion 45 and flows. Even if it does not collide with the exhaust gas whose direction is downward, it collides with the upper wall surface 45a of the protrusion 45. Due to the collision with the upper wall surface 45a, the exhaust gas is reduced in the upward speed component, and the exhaust gas is stirred accordingly, and the mixing of the reducing agent and the exhaust gas contained in the exhaust gas is promoted. The
On the other hand, the exhaust gas that collides with the portion inclined downward of the upper wall surface 45a of the protrusion 45 and the flow direction is directed downward collides with the portion inclined upward of the lower wall surface 45b of the protrusion 45 and flows in the flow direction. Even if it does not collide with the exhaust gas directed upward, it collides with the lower wall surface 45b of the protrusion 45. Due to the collision with the lower wall surface 45b, the downward velocity component of the exhaust gas is lowered, and the exhaust gas is agitated accordingly, and the mixing of the reducing agent contained in the exhaust gas and the exhaust gas is promoted. Is done.
Also, in this embodiment, there is no member that restricts the cross-sectional area of the exhaust gas, so that the reducing agent and exhaust contained in the exhaust gas hardly increase the pressure loss of the exhaust gas. Mixing with gas can be promoted.
By the way, mixing of the reducing agent and the exhaust gas can be promoted with almost no increase in the pressure loss of the exhaust gas by any of the protruding portions having the shapes shown in the first to third embodiments. Here, regardless of the shape of any of these protrusions, the exhaust gas flowing in the lower part of the manifold outlet vicinity 19a collides with the lower wall surface of the protrusion, and the flow direction is directed upward. This is considered to promote the mixing of the reducing agent and the exhaust gas. Accordingly, the protruding portion may have any shape as long as a part of the wall surface can direct the velocity component in the axial direction of the casing 30 of at least a part of the exhaust gas flowing into the protruding portion. I can say that.
Moreover, even if any shape of the projecting portion shown in the first embodiment to the third embodiment is adopted, the exhaust gas flowing through the upper portion of the manifold outlet vicinity 19a collides with the upper wall surface of the projecting portion, It is considered that the flow direction is directed downward and collides with other exhaust gas that has flowed into the protrusion, thereby promoting the mixing of the reducing agent and the exhaust gas. Therefore, the protruding portion is formed such that at least a part of the exhaust gas whose downward velocity component is increased by hitting the wall surface collides with the exhaust gas whose downward velocity component is not increased even if it hits the wall surface of the protruding portion. It can be said that any shape can be used.
Furthermore, even if any shape of the projecting portion shown in the first to third embodiments is adopted, the exhaust gas flowing in the upper portion of the manifold outlet vicinity 19a collides with the upper wall surface of the projecting portion and The flow direction is made downward, and then the downward velocity component of the exhaust gas is reduced due to the collision with the lower wall surface of the protruding portion, thereby promoting the mixing of the reducing agent and the exhaust gas. . Similarly, the exhaust gas flowing in the lower part of the manifold outlet vicinity portion 19a collides with the lower wall surface of the projecting portion so that the flow direction is directed upward, and then the exhaust gas is directed upward by the collision with the upper wall surface of the projecting portion. It is considered that this speed component is reduced, thereby promoting the mixing of the reducing agent and the exhaust gas. Therefore, at least a part of the exhaust gas in which the velocity component in the direction toward the exhaust gas purifying means hits a part of the wall surface of the projecting part hits another part of the wall surface of the projecting part. It can be said that any shape may be used as long as the speed component is formed to be lowered.
Next, a fourth embodiment of the present invention will be described with reference to FIGS. 5A and 5B. 5A and 5B are enlarged views similar to FIGS. 2A and 2B of the catalytic converter 21 of the fourth embodiment. The configuration of the exhaust purification device of the fourth embodiment is basically the same as the configuration of the exhaust purification device of the first embodiment. However, in the exhaust purification device of the first embodiment, the manifold outlet vicinity portion 19a extends perpendicular to the axis L, whereas in this embodiment, the manifold outlet vicinity portion 50a is inclined with respect to the axis L. It extends.
As shown in FIG. 5A, the exhaust manifold 50 of the present embodiment extends through the wall surface of the cone portion 32 in the upper portion of the cone portion 32 of the casing 30. As shown in FIG. 5A, the exhaust manifold 50 is inclined with respect to the axis L of the casing 30 at a location penetrating the wall surface of the cone portion 32. Further, the exhaust manifold 50 extends linearly within the cone portion 32. For this reason, the manifold outlet vicinity portion 50 a also extends with an inclination with respect to the axis L and also extends with an inclination with respect to the wall surface of the cone portion 32.
Further, as shown in FIGS. 5A and 5B, the manifold outlet vicinity portion 50 a extends toward the protruding portion 35. In other words, the manifold outlet vicinity portion 50 a extends so that its axis M enters the protruding portion 35.
The flow of the exhaust gas in the exhaust manifold 50 and the casing 30 configured as described above will be described. Since the manifold outlet vicinity portion 50 a extends toward the protruding portion 35, the exhaust gas containing the reducing agent flowing through the exhaust manifold 50 flows out from the outlet of the exhaust manifold 50 and flows into the protruding portion 35. The exhaust gas flowing in the lower part of the manifold outlet vicinity portion 50a collides with the lower wall surface 35b of the protrusion 35. Due to this collision, the flow direction of the exhaust gas is directed upward. On the other hand, the exhaust gas flowing in the upper part of the manifold outlet vicinity portion 50a flows along the upper wall surface 35a of the protrusion 35 so that its flow direction is directed downward, or collides with the upper wall surface 35a and flows therethrough. Is faced down.
In this way, the exhaust gas that collides with the lower wall surface 35b and the flow direction is directed upward and the exhaust gas that collides with the upper wall surface 35a or collides and the flow direction is directed downward collide with each other. Mixing of the reducing agent contained therein and the exhaust gas is promoted. Further, the exhaust gas that collides with the lower wall surface 35b and whose flow direction is directed upward collides with the upper wall surface 35a, and the exhaust gas that collides with the upper wall surface 35a and whose flow direction is directed downward collides with the lower wall surface 35a. This also promotes mixing of the reducing agent contained in the exhaust gas and the exhaust gas. Further, in the present embodiment, since there is no member for reducing the flow passage cross-sectional area of the exhaust gas, the reducing agent and the exhaust gas contained in the exhaust gas are hardly increased without substantially increasing the pressure loss of the exhaust gas. Mixing with gas can be promoted.
In the present embodiment, it is preferable that the protruding portion 35 is configured to be inclined with respect to the circumferential direction, that is, to be inclined with respect to a plane perpendicular to the axis L. In particular, by inclining the projecting portion 35 so as to be positioned on the lower side as it is away from the region facing the outlet of the exhaust manifold 19 in the circumferential direction, the exhaust gas that has flowed in with respect to the projecting portion 35 is projected. It becomes easy to flow in the circumferential direction in the portion 35.
Next, a fifth embodiment of the present invention will be described with reference to FIGS. 6A and 6B. 6A and 6B are enlarged views similar to FIGS. 2A and 2B of the catalytic converter 21 of the fifth embodiment. The configuration of the exhaust purification device of the fifth embodiment is basically the same as the configuration of the exhaust purification device of the fourth embodiment. However, in the exhaust purification device of the fourth embodiment, the exhaust manifold 50 extends through the wall surface of the cone portion 32 into the cone portion 32, whereas in the exhaust purification device of the fifth embodiment, the exhaust manifold 50 55 does not pass through the wall surface of the cone portion 32, and therefore does not extend into the cone portion 32.
As shown in FIG. 6A, the exhaust manifold 55 of the present embodiment has an outlet portion directly connected to the cone portion 32 of the casing 30. Further, the exhaust manifold 55 extends while being inclined with respect to the axis L, and is inclined with respect to the wall surface of the cone portion 32. Furthermore, as shown in FIG. 6A, the manifold outlet vicinity portion 55 a extends toward the protruding portion 35. In other words, the manifold outlet vicinity 55 a extends so that its axis M enters the protruding portion 35.
In the exhaust manifold 55 and the casing 30 configured as described above, the manifold outlet vicinity portion 55a extends toward the protruding portion 35. Therefore, most of the exhaust gas including the reducing agent flowing through the exhaust manifold 50 is exhausted. It flows out from the outlet of the manifold 55 and flows into the protrusion 35. The exhaust gas flowing in the lower portion of the manifold outlet vicinity portion 50a collides with the lower wall surface 35b of the projection 35, and the flow direction is made upward. On the other hand, the exhaust gas flowing in the upper part of the manifold outlet vicinity portion 50a flows along the upper wall surface 35a of the protrusion 35 or collides with the upper wall surface 35a, and the flow direction is made downward. These exhaust gases collide with each other, thereby promoting the mixing of the reducing agent and the exhaust gas contained in the exhaust gas.
Further, since the distance from the outlet of the exhaust manifold 55 to the protruding portion 35 is large, a part of the exhaust gas flowing out from the outlet of the exhaust manifold 55 does not flow into the protruding portion 35 but is left as it is. _X It flows into the storage reduction catalyst 20. Here, when the exhaust gas flows into the protruding portion 35, the flow direction of the exhaust gas changes abruptly, so that some pressure loss occurs. In contrast, a part of the exhaust gas flowing out from the outlet of the exhaust manifold 55 remains as it is. _X Since it flows into the storage reduction catalyst 20, the flow rate of the exhaust gas flowing into the projecting portion 35 is reduced, and the pressure loss is also reduced accordingly. Also in this embodiment, there is no member that restricts the cross-sectional area of the exhaust gas. For this reason, in this embodiment, mixing of the reducing agent contained in the exhaust gas and the exhaust gas can be promoted while suppressing an increase in the pressure loss of the exhaust gas.
By the way, the exhaust manifold of any shape shown in the first embodiment, the fifth embodiment and the sixth embodiment described above promotes the mixing of the reducing agent and the exhaust gas with almost no increase in the pressure loss of the exhaust gas. Can be made. Here, even if the exhaust manifold of any shape shown in these embodiments is employed, the vicinity of the manifold outlet extends toward the protruding portion, that is, its axis M enters the protruding portion. Thus, it is considered that the mixing of the reducing agent and the exhaust gas is promoted. Therefore, the exhaust manifold may have any shape as long as the axis M in the vicinity of the outlet extends so as to pass through the protruding portion.
Next, a sixth embodiment of the present invention will be described with reference to FIGS. 7A and 7B. 7A and 7B are enlarged views similar to FIGS. 2A and 2B of the catalytic converter 21 of the sixth embodiment. The configuration of the exhaust purification device of the sixth embodiment is basically the same as the configuration of the exhaust purification device of the first embodiment. However, in the exhaust purification device of the first embodiment, the protrusion 35 extends over a half circumference in the circumferential direction of the casing 30, whereas in the present embodiment, the protrusion 60 is in the circumferential direction of the casing 30. It extends less than half a lap.
The flow of the exhaust gas in the exhaust manifold 19 and the casing 30 configured as described above will be described. Similarly to the protrusion 35 of the first embodiment, the exhaust gas flowing into the protrusion 60 collides with the wall surface of the protrusion 60 to change the direction of the flow in the vertical direction, and accordingly, the reducing agent and the exhaust gas. Mixing with is promoted.
On the other hand, in this embodiment, since the protrusion 60 has a small width W in the circumferential direction of the casing 30, unlike the protrusion 35 of the first embodiment, the exhaust gas flowing into the protrusion 60 extends along the wall surface of the protrusion 60. Therefore, it is difficult for the casing 30 to flow toward both sides in the circumferential direction. For this reason, in the protrusion part 60, since the exhaust gas which flowed in does not spread in the circumferential direction, a big disorder | damage | disturbance arises and mixing of a reducing agent and exhaust gas is promoted also by this.
Thus, if the width W in the circumferential direction of the inlet of the protrusion 60 is reduced, the reducing agent and the exhaust gas can be further mixed. However, if the circumferential width W of the inlet of the protrusion 60 is made too small to be smaller than the diameter d of the outlet of the exhaust manifold 19, the width W of the inlet of the protrusion 60 becomes a throttle, and the exhaust gas Pressure loss will increase. For this reason, it is preferable that the width W of the inlet of the protrusion 60 is larger than the diameter d of the outlet of the exhaust manifold 19.
Similarly, when the vertical height of the inlet of the protrusion 60 (the height in the axial direction of the casing 30) is smaller than the diameter d of the outlet of the exhaust manifold 19, the height h of the inlet of the protrusion 60 is reduced. As a result, the pressure loss of the exhaust gas increases. For this reason, the height h of the inlet of the protrusion 60 is preferably larger than the diameter d of the outlet of the exhaust manifold 19.
More precisely, the inlet of the projecting portion 60 becomes a constriction because the sectional area X of the inlet of the projecting portion 60 facing the space in the casing 30 (cone portion 32) is larger than the sectional area of the outlet of the exhaust manifold 19. Is also when it is small. Therefore, in order to prevent an increase in exhaust gas pressure loss due to the restriction of the inlet of the protrusion 60, the cross-sectional area X of the inlet of the protrusion 60 is made smaller than the cross-sectional area of the outlet of the exhaust manifold 19. is required.
Next, a seventh embodiment of the present invention will be described with reference to FIGS. 8A and 8B. 8A and 8B are enlarged views similar to FIGS. 2A and 2B of the catalytic converter 21 of the seventh embodiment. The configuration of the exhaust purification device of the seventh embodiment is basically the same as the configuration of the exhaust purification device of the first embodiment. However, in the exhaust purification device of the first embodiment, the outlet of the exhaust manifold 19 does not enter the protruding portion 35, whereas in the present embodiment, the outlet of the exhaust manifold 19 enters the protruding portion 35. is doing.
Here, a part of the reducing agent supplied from the reducing agent supply device 22 may flow in the exhaust manifold 19 as droplets without being scattered in the exhaust gas flowing in the exhaust manifold 19. Such a reducing agent in the droplet state falls in the direction of gravity from the outlet of the exhaust manifold 19, and NO _X It will flow into the storage reduction catalyst 20. In this way, the reducing agent is not mixed with the exhaust gas and in the droplet state, _X If it flows into the storage reduction catalyst 20, the exhaust gas may not be sufficiently purified. For this reason, the reducing agent is in a droplet state and NO. _X It is necessary not to flow into the storage reduction catalyst 20.
In the present embodiment, as described above, the outlet of the exhaust manifold 19 enters the protruding portion 35. Therefore, even if the reducing agent falls in the direction of gravity from the outlet of the exhaust manifold 19 in the droplet state, the reducing agent is NO. _X It does not fall directly on the storage reduction catalyst 20, but adheres to the lower side wall surface 3b of the protrusion 35.
Here, as described above, since the turbulence of the exhaust gas is generated in the protrusion 35, the reducing agent in a droplet state attached on the lower wall surface 35b of the protrusion 35 is thereby evaporated, and then It will be mixed with the exhaust gas. Therefore, according to the present embodiment, even if a part of the reducing agent supplied from the reducing agent supply device 22 flows out from the exhaust manifold 19 in a droplet state, the reducing agent and the exhaust gas are appropriately mixed. be able to.
Next, an eighth embodiment of the present invention will be described with reference to FIGS. 9A and 9B. 9A and 9B are views similar to FIGS. 2A and 2B of the catalytic converter 21 of the eighth embodiment. The configuration of the exhaust purification device of the eighth embodiment is basically the same as the configuration of the exhaust purification device of the first embodiment. However, in the exhaust purification device of the first embodiment, the protruding portion 35 is provided on the inner wall surface portion of the cone portion 32 facing the outlet of the exhaust manifold 19, whereas in the present embodiment, the casing 30 Two projecting

members

71 and 72 projecting radially inward are provided.
As shown in the side sectional view of FIG. 9A, the lower wall surface 71a of the upper protrusion member 71 is inclined downward toward the radially outer side of the casing 30, and the upper wall surface 71b of the upper protrusion member 71 is the casing. 30 is inclined upward in the radial direction. On the other hand, the upper wall surface 72 a of the lower protrusion member 72 is inclined upward toward the radially outer side of the casing 30, and the lower wall surface 72 b of the lower protrusion member 72 is directed toward the radially outer side of the casing 30. Inclined downward. In the illustrated embodiment, the lower wall surface 71a of the upper protruding member 71 and the upper wall surface 72a of the lower protruding member 72 are curved in a concave shape.
Further, as shown in FIG. 9B, these projecting

members

71 and 72 extend from the region facing the outlet of the exhaust manifold 19 toward both sides in the circumferential direction of the casing 30. When the depth of the projecting

members

71 and 72 projecting most in the radial direction of the casing 30 from the inner wall surface of the cone portion 32 when there is no projecting

member

71 and 72 is D, the depth D of the projecting

members

71 and 72 is the exhaust manifold. It becomes shallow as it leaves | separates in the circumferential direction of the casing 30 from the area | region which 19 faces. In particular, as shown in FIG. 9B, in this embodiment, the inner circumferences of the projecting

members

71 and 72 are formed to be substantially semi-elliptical. Further, in the present embodiment, the projecting

members

71 and 72 extend over a half circumference in the circumferential direction of the casing 30.
The exhaust manifold 19 and the casing 30 configured as described above can achieve the same effects as those of the first embodiment shown in FIGS. 2A and 2B. That is, the exhaust gas containing the reducing agent that has flowed through the exhaust manifold 19 flows out from the outlet of the exhaust manifold 19 and flows into the space between the projecting

members

71 and 72. The exhaust gas flowing in the lower part of the manifold outlet vicinity 19 a collides with the upper wall surface 72 a of the lower protrusion member 72. Due to this collision, the flow direction of the exhaust gas is directed upward. On the other hand, the exhaust gas flowing in the upper part of the manifold outlet vicinity 19 a collides with the lower side wall surface 71 a of the upper protruding member 71. This collision causes the exhaust gas to flow downward.
When the flow direction of the exhaust gas colliding with the upper wall surface 72a of the lower projection member 72 is made upward and the flow direction of the exhaust gas colliding with the lower wall surface 71a of the upper projection member 71 is made downward, these The exhaust gases will collide with each other. In this way, the exhaust gas is agitated by the collision of the two exhaust gases, thereby promoting the mixing of the reducing agent contained in the exhaust gas and the exhaust gas.
Further, the exhaust gas that has collided with the upper wall surface 72a of the lower projecting member 72 and whose flow direction has been directed upward is the exhaust gas that has collided with the lower wall surface 71a of the upper projecting member 71 and has its flow direction directed downward. Even if it does not collide with, it collides with the upper wall surface 72a of the lower projection member 72. Due to the collision with the upper wall surface 72a, the upward velocity component of the exhaust gas is reduced and the exhaust gas is agitated accordingly, and the mixing of the reducing agent and the exhaust gas contained in the exhaust gas is promoted. The This also applies to the exhaust gas that collides with the lower wall surface 71a of the upper projecting member 71 and whose flow direction is directed downward.
In the eighth embodiment, the protruding

members

71 and 72 separate from the casing 30 are provided on the inner wall surface of the casing 30, but the inner wall surface of the casing 30 protrudes radially inward of the casing 30. In this manner, a protruding portion may be provided on the inner wall surface of the casing 30. Therefore, in summary, it can be said that the exhaust emission control device of the present embodiment includes a protrusion that protrudes from the inner wall surface defining the casing 30 toward the radially inner side of the casing 30.
In summary, the flow deflecting portion (for example, the

protrusions

35, 40, 45, provided on the inner wall surface of the casing 30, is provided on a portion of the inner wall surface of the casing 30 facing the exhaust manifold outlet vicinity portion 19 a. 60 and protrusions 71 and 72), and the flow deflector is NO. _X The speed component in the axial direction of the casing 30 of the flow of at least a part of the exhaust gas flowing into the flow deflector is positioned NO on the upstream side of the storage reduction catalyst 20. _X It can be said that it is formed so as to be directed in the direction opposite to the direction toward the storage reduction catalyst 20.
Alternatively, a flow deflection portion is provided in a portion of the inner wall surface of the casing 30 that faces the exhaust manifold outlet vicinity portion 19a, and the flow deflection portion is _X It is located upstream from the storage reduction catalyst 20, and the wall surface of the flow deflection unit hits a part of the wall surface of the flow deflection unit, so that NO. _X It is formed so that at least a part of the exhaust gas whose velocity component in the direction toward the storage reduction catalyst 20 is increased hits the other part of the wall surface of the flow deflector, and the velocity component in the same direction of the exhaust gas is reduced. It can be said.
In the above embodiment, the exhaust manifold 19 connected to the engine body 1 is directly connected to the casing 30 of the catalytic converter 21, but the exhaust pipe connected directly or indirectly to the exhaust manifold 19 is connected to the catalyst. You may make it connect with the casing 30 of the converter 21. FIG.
It is also possible to configure the exhaust purification device by combining the above embodiments. For example, by combining the exhaust purification device of the second embodiment and the fourth embodiment, the cross section of the protruding portion in the circumferential direction of the casing 30 is rectangular, and the vicinity of the manifold outlet extends inclined with respect to the axis L. It can be set as an exhaust emission control device. Further, for example, by combining the exhaust purification device of the second embodiment and the eighth embodiment, the lower wall surface 71 a of the upper protrusion member 71 and the upper wall surface 72 a of the downstream protrusion member 72 are perpendicular to the axial direction of the casing 30. A simple exhaust purification device.
Although the present invention has been described in detail based on specific embodiments, those skilled in the art can make various changes and modifications without departing from the scope and spirit of the present invention.

19, 50, 55

Exhaust manifold

19a, 50a, 55a Manifold outlet vicinity 20 NO _X storage reduction catalyst 21 Catalytic converter 30 Casing 31 Catalyst housing part 32

Cone part

35, 40, 45, 60 Projection part

Claims

An upstream exhaust passage through which exhaust gas discharged from the internal combustion engine flows, a downstream exhaust passage disposed at an angle with respect to the upstream exhaust passage downstream of the upstream exhaust passage, and an upstream exhaust passage In an exhaust gas purification apparatus for an internal combustion engine comprising a reducing agent supply means for supplying a reducing agent into exhaust gas passing through the exhaust gas, and an exhaust gas purification means provided in a downstream exhaust passage,
A flow deflecting portion is provided in a portion of the inner wall surface defining the downstream exhaust passage facing the upstream exhaust passage outlet, and the flow deflecting portion is located upstream of the exhaust purification means and the flow deflecting portion. An exhaust gas purification apparatus for an internal combustion engine configured to direct a velocity component in the downstream exhaust passage axial direction of at least a part of the flow of exhaust gas flowing into the section in a direction opposite to a direction toward the exhaust gas purification means.
The region on the exhaust purification means side of the wall surface defining the flow deflection section has a portion inclined in the direction opposite to the direction toward the exhaust purification means toward the radially outer side of the downstream exhaust passage. Exhaust gas purification device for internal combustion engine.
An upstream exhaust passage through which exhaust gas discharged from the internal combustion engine flows, a downstream exhaust passage disposed at an angle with respect to the upstream exhaust passage downstream of the upstream exhaust passage, and an upstream exhaust passage In an exhaust gas purification apparatus for an internal combustion engine comprising a reducing agent supply means for supplying a reducing agent into exhaust gas passing through the exhaust gas, and an exhaust gas purification means provided in a downstream exhaust passage,
A flow deflecting portion is provided in a portion of the inner wall surface defining the downstream exhaust passage facing the upstream exhaust passage outlet, and the flow deflecting portion is located upstream of the exhaust purification means. The wall surface hits a part of the wall surface of the flow deflection unit and at least a part of the exhaust gas whose velocity component in the direction toward the exhaust gas purification unit is increased hits the other part of the wall surface of the flow deflection unit. An exhaust purification device for an internal combustion engine, which is formed so as to reduce a speed component in the same direction.
The region on the side of the wall surface defining the flow deflection portion away from the exhaust purification means has a portion inclined in the direction toward the exhaust purification means toward the radially outer side of the downstream exhaust passage. An exhaust purification device for an internal combustion engine.
5. The flow deflecting portion includes a projecting portion in which an inner wall surface itself defining a downstream exhaust passage projects from a radially outer side of the downstream exhaust passage. 2. An exhaust gas purification apparatus for an internal combustion engine according to 1.
6. The exhaust gas purification apparatus for an internal combustion engine according to claim 5, wherein a cross section in the circumferential direction of the downstream side exhaust passage of the protrusion is substantially semi-elliptical.
The exhaust purification device for an internal combustion engine according to claim 5 or 6, wherein an inlet area of the projecting portion facing the downstream exhaust passage is larger than a cross-sectional area of the upstream exhaust passage.
The exhaust gas purification apparatus for an internal combustion engine according to claim 7, wherein the height of the protruding portion in the axial direction of the downstream exhaust passage is larger than the diameter of the upstream exhaust passage.
The exhaust purification device for an internal combustion engine according to any one of claims 5 to 8, wherein the protrusion extends in a circumferential direction of the downstream exhaust passage.
10. The exhaust gas purification apparatus for an internal combustion engine according to claim 9, wherein the depth of the projecting portion in the downstream exhaust passage radial direction decreases as the distance from the region facing the upstream exhaust passage outlet decreases.
The exhaust purification device for an internal combustion engine according to claim 9 or 10, wherein the protrusion is formed so that an outer periphery thereof is substantially semi-elliptical.
12. The projection according to any one of claims 9 to 11, wherein the protruding portion is inclined so as to be positioned on the exhaust purification means side as the distance from the region facing the upstream exhaust passage outlet in the circumferential direction of the downstream exhaust passage increases. An exhaust gas purification apparatus for an internal combustion engine as described.
13. The exhaust gas purification apparatus for an internal combustion engine according to claim 5, wherein the upstream exhaust passage extends in a vicinity of an outlet thereof so that a central axis thereof passes through the protruding portion.
14. The exhaust gas purification apparatus for an internal combustion engine according to claim 5, wherein the upstream exhaust passage extends in the vicinity of an outlet thereof with an inclination with respect to the central axis of the downstream exhaust passage.
The exhaust purification device for an internal combustion engine according to any one of claims 5 to 13, wherein the upstream exhaust passage extends perpendicularly to the central axis of the downstream exhaust passage in the vicinity of the outlet thereof.
16. The exhaust gas purification apparatus for an internal combustion engine according to claim 5, wherein the upstream exhaust passage enters and extends into the downstream exhaust passage.
The internal combustion engine exhaust gas purification apparatus according to any one of claims 5 to 16, wherein the upstream side exhaust passage outlet is allowed to enter the protrusion.
The flow deflector includes a protruding portion formed such that an inner wall surface defining the downstream exhaust passage protrudes radially outward of the downstream exhaust passage, and the downstream exhaust passage circumferential direction of the protruding portion The exhaust gas purification apparatus for an internal combustion engine according to claim 1 or 3, wherein the cross-section of the internal combustion engine is substantially rectangular.
The internal combustion engine according to any one of claims 1 to 18, wherein the flow deflection section includes a protrusion that protrudes from an inner wall surface defining a downstream exhaust passage toward a radially inner side of the downstream exhaust passage. Engine exhaust purification system.
The upstream exhaust passage is defined by an exhaust manifold or an exhaust pipe directly connected to the exhaust manifold, and the downstream exhaust passage is a cone portion provided in an upstream portion of a catalytic converter that houses exhaust purification means. Item 20. An exhaust emission control device for an internal combustion engine according to any one of Items 1 to 19.