RU2425231C2 - Device for exhaust gases cleaning - Google Patents

Abstract

FIELD: machine building. ^ SUBSTANCE: cooling water is supplied into circular duct (62) in mounting part (60) assembled with sprayer (50) for injection of additive into exhaust duct (12) communicating with engine (11). Inlet duct (81) for inlet of cooling water and outlet duct (91) for output of cooling water are connected to duct (62) of cooling water, and, at least inlet duct (81) is projected in the direction tangential to duct (62) of cooling water. Converging part (62a), with width of the duct of water decreased with projecting part (63) which corresponds to a part of a side wall in the direction along circumference of duct (62) of cooling water, is made in position of duct (62) of cooling water near connection between duct (62) of cooling water and inlet duct (81). ^ EFFECT: cleaning exhaust gases during long time by means of efficient cooling sprayer for injection of additive into exhaust duct. ^ 4 cl, 8 dwg

Description

The present invention relates to an exhaust aftertreatment device for treating exhaust gas discharged from an engine.

State of the art

Exhaust gas discharged from an engine installed in an automobile or similar, particularly a diesel engine, contains a large amount of carbon monoxide (CO), hydrocarbons (HC), nitrogen oxides (NO _x ), particulate matter (PM) and so on. Typically, for this reason, in the exhaust path through which the exhaust gas discharged from the engine is provided, for example, a three-way catalyst for decomposing (e.g. recovering) said pollutants and a particulate filter or the like for collecting particulate matter such so that the gas is released into the atmosphere in the most detoxified state possible.

A similar particulate filter should be recovered if necessary, since solid particles accumulate inside the filter during use, thereby increasing the resistance to passage. A traditional method for such recovery purposes has been to arrange the heating device in a particulate filter and to burn solid particles by heating, thereby removing solid particles. A method has also been proposed that comprises pouring a hydrocarbon-based liquid, such as fuel (light oil products), into an oxidizing converter provided upstream of the particulate filter to cause an exothermic reaction with the possibility of performing the recovery of the particulate filter by heat from this reaction .

The diesel engine also especially permits the presence of large amounts of nitrogen oxides (NO _x ). For a diesel engine, for this reason, the so-called catalytic converter (NO _x converter), for example, is used in large quantities to frequently perform adsorption and reduction of NO _x for decomposition (reduction) of NO _x in order to efficiently decompose NO _x in the exhaust gas.

The catalytic converter must accordingly be provided externally with a reducing agent for the decomposition (reduction) of adsorbed NO _x . Typically, for this reason, fuel (light oil products) or the like is injected as a reducing agent into the exhaust tract and is thus fed to the catalytic converter. In some devices, for example, NO _x reductant is injected towards the catalytic converter by means of a nozzle provided in the exhaust pipe (see, for example, Patent Document 1).

Description of the invention

Technical problem

With such a configuration in which a reducing agent (additive), such as fuel, is injected from the nozzle into the exhaust path, the surface of the front end of the nozzle is open into the exhaust path and is exposed to high temperature of the exhaust gas. Thus, the temperature of the nozzle can rise beyond the temperature limit ensuring its heat resistance, thus leading to burnout. The result of an increase in the temperature of the nozzle is also the sticking of fumes of volatile fuel components to the surface of the front end of the nozzle and the deterioration and precipitation of the remaining components. Moreover, the reducing agent adhering to the surface of the front end plays the role of a binder, which causes adhesion and gradual accumulation in the form of sediment of soot from the exhaust gas. These deposits can clog the nozzle nozzle, whereby the problem is that the reducing agent can no longer be supplied to the exhaust tract and the exhaust gas can no longer be cleaned.

To solve these problems, a device was proposed, for example, in which a water jacket (cooling water path) is formed around the nozzle, and cooling water is supplied to the water jacket and circulated therein to reduce the temperature increase of the nozzle (see, for example, Patent Document 2).

The increase in nozzle temperature is suppressed to some extent by providing such a cooling water path. However, simply providing a cooling water path around the nozzle may not sufficiently cool the nozzle. Thus, an additional effective cooling measure was required.

The present invention has been made in light of the above situations. An object of the present invention is to provide an exhaust purification device that can satisfactorily clean exhaust gas for a long period of time by efficiently cooling the nozzle to inject the additive into the exhaust tract.

Solution

The first aspect of the present invention to solve the above problems is an exhaust purification device including an exhaust purification catalyst disposed in an exhaust tract in communication with the engine, an injector located upstream of the exhaust purification catalyst for injecting an additive into the exhaust tract, and a mounting part having a mounting hole in which the nozzle is mounted, an annular cooling water path into which cooling water is supplied, and which is provided around the mounting hole m ntazhnoy parts, wherein the inlet path for cooling water inlet and outlet path for discharging the cooling water are connected to a cooling water path, and at least an intake path extends in a direction tangential to the path of the cooling water; and a narrowed portion having a water path width reduced by a protruding portion that is a protrusion of a side wall portion in a direction along the circumference of the cooling water path, and provided at a location of the cooling water path close to the connection between the cooling water path and the intake path.

According to a first aspect, cooling water supplied from the inlet path to the cooling water path collides with a protruding portion to form a turbulent flow, thereby improving the cooling effect of the nozzle. Moreover, cooling water passes through the narrowed portion to increase its flow rate, thereby improving the cooling effect of the nozzle. As a result, the nozzle is completely cooled to suppress sedimentation. Thus, the exhaust gas can satisfactorily be cleaned over a long period of time.

A second aspect of the present invention is an exhaust purification device according to a first aspect, characterized in that the inlet and the outlet are connected to an identical position in the direction along the circumference of the cooling water path.

According to a second aspect, the cooling water supplied from the inlet path to the cooling water path makes at least one bypass of the cooling water path and is then discharged from the exhaust path. Therefore, the nozzle can be effectively cooled by cooling water. According to this feature, moreover, a part of the cooling water hitting the protruding part flows in the opposite direction in the cooling water path and collides with the main stream, which passed through the narrowed part, causing an additional turbulent flow. This turbulent flow further increases nozzle cooling efficiency.

A third aspect of the present invention is an exhaust cleaning device according to the first or second aspect, characterized in that the nozzle is held by the mounting part and the fixing part attached to the mounting part, and the protruding part constitutes a bulge to which a fastener is attached to fasten the fixing part to the mounting part.

According to a third aspect, a reduction in the size of the mounting part can be achieved by efficiently using the protruding part.

A fourth aspect of the present invention is an exhaust purification device according to any one of the first to third aspects, characterized in that the constricted portion is provided along the entire direction of the height of the cooling water path.

According to a fourth aspect, the speed of the main flow of cooling water is increased more reliably, and the cooling water collides with the protruding portion reliably, thereby improving the intensity of turbulence. Thus, the nozzle can be cooled even more efficiently.

Advantageous Effects of the Invention

According to the exhaust cleaning device of the present invention described above, the nozzle for injecting the additive into the exhaust tract is effectively cooled. Thus, problems such as clogging of the nozzle due to accumulation of precipitation associated with the increase in temperature of the nozzle can be prevented. Therefore, the exhaust gas can satisfactorily be cleaned over a long period of time.

Brief Description of the Drawings

1 is a view showing a schematic configuration of an exhaust aftertreatment apparatus according to an embodiment of the present invention.

FIG. 2 is a sectional view of a mounting part on which a nozzle according to an embodiment is mounted.

FIG. 3 is another sectional view of a mounting part on which a nozzle according to an embodiment is mounted.

FIG. 4 is another sectional view of a mounting part on which a nozzle according to an embodiment is mounted.

5 is a sectional view showing a modified example of a mounting member according to an embodiment.

6 is another cross-sectional view showing a modified example of a mounting member according to an embodiment.

7 is another cross-sectional view showing a modified example of a mounting member according to an embodiment.

8 (a) to 8 (c) are schematic configuration drawings showing modified examples of an exhaust cleaning device.

Description of Embodiments

An embodiment of the present invention will now be described in detail.

1 is a view showing a schematic configuration of an exhaust aftertreatment apparatus according to an embodiment of the present invention. As shown in FIG. 1, the exhaust purification device 10 includes a plurality of exhaust purification converters and an exhaust purification filter. Many exhaust purification converters and an exhaust purification filter are located in the exhaust pipe (exhaust tract) 12 of the multi-cylinder diesel engine (hereinafter referred to simply as the engine) 11 installed in the vehicle.

The engine 11 includes a cylinder head 13 and a cylinder block 14, and a piston 16 is arranged with a reciprocating motion inside each hole 15 in the cylinder block. The piston 16, the hole 15 in the cylinder block and the head 13 of the cylinder block make up the combustion chamber 17. The piston 16 is connected to the crankshaft 19 by means of a connecting rod 18, and the reciprocating movement of the piston 16 rotates the crankshaft 19.

An inlet channel 20 is formed in the cylinder head 13, and an inlet pipe (inlet) 22 is connected to the inlet channel 20, including an inlet manifold 21. An inlet valve 23 is provided in the inlet channel 20, and the inlet channel 20 is opened and closed by the inlet valve 23 An exhaust channel 24 is formed in the cylinder head 13, and an exhaust pipe (exhaust path) 12 is connected to the exhaust channel 24, including an exhaust manifold 24. An exhaust valve 26 is provided in the exhaust channel 24, and, like the inlet channel 20, the exhaust Noya channel 24 is opened and closed by exhaust valve 26. Turbocharger 27 is provided halfway in the inlet pipe 22 and exhaust pipe 12, and the exhaust aftertreatment catalysts and the exhaust aftertreatment filter constituting the exhaust aftertreatment device 10 are located in the exhaust pipe 12 downstream of the turbocharger 27 .

The turbocharger 27 has a turbine (not shown) and a compressor (not shown) connected to this turbine. When the exhaust gas flows from the engine 11 to the turbocharger 27, the turbine is rotated by the exhaust gas flow, and in accordance with the rotation of the turbine, the compressor rotates to take air from the intake pipe 22a to the turbocharger 27 to compress it. Air compressed in the turbocharger 27 is supplied to each inlet channel 20 of the engine 11 through the inlet pipe 22b.

An electronically controlled fuel nozzle 31 is provided in the cylinder head 13 for direct fuel injection into the combustion chamber 17 of each cylinder. High pressure fuel, adjusted to a predetermined fuel pressure, is supplied to the fuel injector 31 from a common fuel line (not shown).

In the present embodiment, the diesel oxidizing catalyst (hereinafter referred to simply as the oxidizing catalyst) 32 and the catalytic converter 33, which are exhaust purification catalysts, and the diesel particulate filter 34 (DPF), which is an exhaust purification filter, are arranged in this order, starting from the upstream side, in the exhaust pipe 12 downstream of the turbocharger 27. Injector 50 for injecting fuel (light petroleum products), which is a reducing agent (additive), into the exhaust the support tube 12a is located between the turbocharger 27 and the oxidizing converters 32, as will be described in detail below.

The oxidizing agent 32 contains, for example, a precious metal such as platinum (Pt) or palladium (Pd) deposited on a honeycomb carrier formed from a ceramic material. When the exhaust gas flows into the oxidizing catalyst 32, the nitric oxide (NO) in the exhaust gas is oxidized to form nitrogen dioxide (NO ₂ ). In order for an oxidizing reaction to occur in the oxidizing catalyst 32, the oxidizing catalyst 32 must be heated to a predetermined temperature or higher. Thus, the oxidizing converter 32 is preferably located as close as possible to the engine 11. This is because the oxidizing converter is heated by heat from the engine 11, and even when the engine is started, the oxidizing converter 32 can be heated to a predetermined temperature or higher in a relatively short time.

The catalytic converter 33 contains, for example, a precious metal such as platinum (Pt) or palladium (Pd) deposited on a honeycomb carrier formed from alumina (Al ₂ O ₃ ), and also has an alkali metal or alkaline earth metal, such as barium (Ba) applied as a trapping agent to the carrier. In the catalyst 33, NO _x , i.e., NO ₂ formed by the oxidizing catalyst 32, or NO remaining in the exhaust gas not oxidized by the oxidizing catalyst 32, is captured once in the oxidizing atmosphere, and NO _{x is} released into the reducing atmosphere containing, for example, oxide carbon (CO), hydrocarbons (HC), and so on, to be reduced to nitrogen (N ₂ ) or the like.

The main amount of NO ₂ formed by the oxidizing catalyst 32 is adsorbed and decomposed (reduced) by the catalytic converter 33, and the remaining NO ₂ which has not been adsorbed or decomposed is purified by the reaction in the diesel particulate filter 34.

The main amount of exhaust gas discharged from the engine 11 is usually responsible for NO, and the HC content in the exhaust gas is extremely small. Thus, the interior of the catalyst 33 is in an oxidizing atmosphere, and in the catalyst 33, NO _{x is} only adsorbed and the adsorbed NO _{x are} not decomposed (not reduced). When a predetermined amount of NO _{x is} adsorbed in the catalyst 33, therefore, fuel (light oil) is injected as an additive from the nozzle 50 attached to the exhaust pipe 12a located between the turbocharger 27 and the oxidizing catalyst 32. As a result, the exhaust gas mixed with the fuel passes through the oxidizing catalyst 32 and is supplied to the catalytic converter 33, whereby the internal space of the catalytic converter 33 is reduced to w atmosphere, the adsorbed NO _x and decompose (restored).

The diesel particulate filter 34 is, for example, a honeycomb filter formed from a ceramic material. The exhaust gas paths 38, each of which has an open end upstream and a closed end downstream, and the exhaust gas paths 39, each of which has an open end downstream and a closed end upstream, are alternately located inside the solid diesel filter 34 particles. The exhaust gas first flows into the exhaust gas path 38, open from the end upstream, passes through the surface of the porous wall provided between the exhaust gas path 38 and the adjacent exhaust gas path 39, then flows into the exhaust gas path 39, open from the downstream end , and flows from the downstream side. During this process, solid particles in the exhaust gas collide or adsorb to the surface of the wall to trap.

Captured solid particles are oxidized (burned) by NO ₂ contained in the exhaust gas and released as CO ₂ . NO ₂ remaining inside the diesel particulate filter 34 decomposes to N ₂ and is released. Therefore, the diesel particulate filter 34 is configured to clean the exhaust gas, thereby allowing a marked reduction in the amount of particulate matter and NO _x produced. Since solid particles are burned, the performance of the diesel particulate filter 34 is also restored to some extent.

Typically, NO _{x is} adsorbed by the catalyst 33, as described above. Thus, the amount of NO ₂ in the exhaust gas supplied to the diesel particulate filter 34 is small, and solid particles gradually accumulate in the diesel particulate filter 34. When a predetermined amount of particulate matter has accumulated in the diesel particulate filter 34, a predetermined amount of fuel is injected from the nozzle 50 attached to the exhaust pipe 12a. When the fuel is mixed with the exhaust gas, as mentioned above, the adsorbed NO _{x are} reduced in the catalytic converter 33. Thus, the NO _x (NO ₂ ) contained in the exhaust gas is not adsorbed by the catalytic converter 33, but fed to the diesel particulate filter 34. As a result, the combustion of solid particles in the diesel particulate filter 34 is accelerated.

Exhaust gas temperature sensors 40 are provided upstream and close to the oxidizing catalyst 32, catalytic converter 33, and diesel particulate filter 34 and downstream and close to the diesel particulate filter 34. The temperatures of the exhaust gas flowing to the oxidizing catalyst 32, the catalytic converter 33 and the diesel particulate filter 34, and the temperatures of the exhaust gas discharged from the oxidizing catalyst 32, the catalyst 33 and the diesel particulate filter 34 are determined by this plurality of exhaust gas temperature sensors 40. Moreover, oxygen concentration sensors 41 for determining the oxygen concentration in the exhaust gas are provided upstream and close to the oxidizing catalyst 32 and the diesel particulate filter 34. The vehicle also has an electronic control unit (ECU), although this is not shown. This electronic control unit is equipped with an input / output device, a memory device for storing a program, a control board, etc., a central processor, timers and counters. Based on information from each of the sensors, the electronic control unit performs integrated control of the engine 11 and the exhaust purification device 10.

FIG. 2 is a sectional view of a mounting member according to the present embodiment. FIG. 3 is a sectional view taken along line A-A 'in FIG. 2. FIG. 4 is a sectional view taken along line B-B 'in FIG. 3. As shown in FIG. 2-4, the injector 50 for injecting fuel as a reducing agent (additive) in the present embodiment is located in a direction almost at right angles to the exhaust pipe 12a and is held by a mounting part 60 attached to the exhaust pipe 12a and a fixing part 70 attached to the mounting details 60.

A mounting hole 61, which is a through hole into which the nozzle 50 is mounted, is formed in the central part of the mounting part 60. The nozzle 50 mounted in the mounting hole 61 is attached to the mounting part 60 by a fixing part 70 in a state in which the surface 52 of the front end of the nozzle 50 in which the nozzle 51 is opened, is open inside the exhaust pipe (exhaust tract), that is, the front end of the nozzle 50 is affected by the exhaust gas. In the present embodiment, for example, the locking part 70 is attached to the mounting part by a fastener 75, such as a bolt.

In the mounting part 60, an annular cooling water path 62 is provided around the mounting hole 61. An inlet path 81 for supplying cooling water to the cooling water path 62 and an exhaust path 91 for discharging cooling water that has circulated in the cooling water path 62 are connected to the cooling water path 62 . That is, an inlet pipe 80 having an inlet path 81 and an exhaust pipe 90 having an exhaust path 91 are connected to the mounting part 60, and the inlet path 81 (inlet pipe 80) and the exhaust path 91 (exhaust pipe 91) are tangential to the annular tract 62 cooling water. In the present embodiment, the intake path 81 and the exhaust path 91 are attached to an identical position in the circumferential direction of the cooling water path 62. In the axial direction of the mounting hole 61, the inlet path 81 is located closer to the nozzle 50 end closest to the attachment point than the exhaust path 91.

In such a configuration, cooling water admitted from the intake path 81 is circulated in the cooling water path 62 and discharged from the exhaust path 91, whereby the nozzle 50 is cooled. In the present embodiment, the intake path 81 and the exhaust path 91 are attached to an identical position along the circumference of the cooling water path 62, as described above. Thus, the cooling water supplied from the intake path 81 to the cooling water path 62 performs at least one bypass of the cooling water path 62 and is then discharged from the exhaust path 91. Therefore, the nozzle 50 can be effectively cooled by the cooling water.

In the present invention, furthermore, a narrowed portion 62a having a water path width reduced by a protruding portion 63, which is a protrusion of a side wall portion of the cooling water path 62, is provided at a location of the cooling water path 62 close to the connection between the cooling water path 62 and the intake path 81, namely at the location of the cooling water path 62 close to the outlet of the intake path 81. Thus, the nozzle 50 can be cooled efficiently.

The protruding portion 63 according to the present embodiment is provided so that a portion of the side wall of the coolant path 62 projects in a semicircle shape to a position where the cooling water supplied from the intake path 81 hits it, as shown in FIG. 3. A constricted portion 62a is formed having a water path width reduced by the protruding portion 63. In the present embodiment, this protruding portion is provided to protrude only partially in the depth direction (axial direction of the mounting hole 61) of the coolant path 62, that is, only in the region opposite the intake tract 81.

According to the configuration described above, the cooling water supplied from the intake path 81 to the cooling water path 62 collides with a protruding portion 63 to form a turbulent flow, thereby improving the cooling effect of the nozzle 50. Specifically, if the cooling water flows in the direction indicated by arrows in FIG. . 3, a portion of the cooling water becomes the main stream (direct flow) passing through the narrowed portion 62a and circulating in the cooling water path 62. A portion of the cooling water striking the protruding portion 63 flows in the opposite direction and collides with the main stream that has passed through the narrowed portion 62a. The result of this collision is the appearance of a turbulent flow and the heat transfer coefficient of the region in which the turbulent flow appears is increased. The passage of cooling water through the narrowed portion 62a increases the speed of the main stream. In accordance with the increase in flow velocity, the turbulence intensity is improved due to said collision, so that the heat transfer coefficient is further increased. Moreover, the cooling effect in the narrowed portion 62a is also improved by increasing the flow rate of cooling water in the narrowed portion 62a. As a result of this, the nozzle 50 is effectively cooled. In this way, problems such as burnout of the nozzle 50 or clogging of the nozzle 51 are suppressed, and the exhaust gas can satisfactorily be cleaned over a long period of time.

The position in which the turbulent flow arises due to the collision of the cooling water is preferably located in the region on the side opposite to the narrowed portion 62a on the other side of the nozzle 50. Since the turbulent flow forms in this position, the nozzle 50 can be cooled even more efficiently. The position in which the turbulent flow occurs inside the cooling water path 62 can be set to the desired position by adjusting the profile, the size of the protrusion, etc. protruding part 63.

Since the turbulent flow can be triggered at the desired position, as mentioned above, there are no restrictions on the size of the protrusion, profile, etc. protruding portion 63. In the present embodiment, for example, the protruding portion 63 is provided to protrude only in the area opposite to the inlet tract 81. However, this is not a limitation, and as shown in FIG. 5, the protruding portion 63 may be provided continuously in the entire direction into the depth of the cooling water path 62.

In the present embodiment, the protrusion of the protruding part 63 in the form of a semicircle is allowed so that the surface of the end of the protruding part 63 consists of a curved surface. In this case, the flow of cooling water seems relatively smooth. However, the end surface of the protruding portion 63 does not always have to be a curved surface. As shown in FIG. 6, for example, a protruding portion 63 may be formed, having an almost triangular contour in cross section, so that the surface of its end consists of a flat surface.

In a configuration in which said protruding portion 63 is provided, furthermore, the width of the cooling water path 62 is gradually changed before and after the narrowed portion 62a. However, as shown in FIG. 7, for example, an edge portion 63a may be provided in the protruding portion 63 on the side opposite the inlet path 81 to dramatically increase the width of the cooling water path 62 downstream of the narrowed portion 62a. In this case, a stream (whirlpool) appears along the edge portion 63a downstream of the protruding portion 63, as indicated by the arrow in FIG. 7. Since the heat transfer efficiency is increased by this flow (swirl) of cooling water, the nozzle 50 can be cooled more satisfactorily.

The locking part 70 for fixing the nozzle 50 is attached to the mounting part 60 by the fastener 75, as mentioned above. In the present embodiment, the aforementioned protruding portion 63 constitutes a bulge having a mounting hole 65 in which the fastener 75 is fixed. As a result of the effective use of the bulging portion 63 provided in the mounting part 60, it becomes unnecessary to provide a separate area for providing a bulge in mounting part 60. That is, the effect is achieved that providing a protruding portion 63 in the mounting part 60 can achieve a reduction in mounting size part 60.

An embodiment of the present invention has been described above. However, the present invention is not limited to this embodiment. In the above embodiment, for example, the intake path 81 and the exhaust path 91 are attached to an identical position along the circumference of the cooling water path 62. Of course, this is not a limitation, and the inlet path 81 and the exhaust path 91 can be connected to different positions in the direction along the circumference of the cooling water path 62. The above embodiment further shows a configuration in which the inlet path 81 and the outlet path 91 protrude tangentially with respect to the annular cooling water path 62. However, it is sufficient that at least the inlet path 81 protrude tangentially with respect to the annular cooling water path 62. No particular restrictions are imposed on the direction of the protrusion of the exhaust tract 91.

In the aforementioned embodiment, for example, an example of an exhaust aftertreatment device 10 is provided in which the oxidizing catalyst 32 and the catalytic converter 33 as exhaust aftertreatment catalysts and a diesel particulate filter 34 as an exhaust aftertreatment filter are located on an exhaust pipe (exhaust path) 12 in the following Sequences from upstream to downstream: oxidizing catalyst 32, catalytic converter 33, and diesel particulate filter 34. However, the location and types of exhaust purification catalysts and exhaust purification filter are not limited. As shown in FIG. 8 (a), for example, an oxidizing catalyst 32, a catalytic converter 33, and a diesel particulate filter 34 may be arranged in this order on the exhaust pipe 12 downstream of the turbocharger 27. Alternatively, as shown in FIG. 8 (b), for example, a catalytic converter 33 and a diesel particulate filter 34 can be arranged in this order on the exhaust pipe 12 downstream of the turbocharger 27 without providing an oxidizing catalyst 32. As another alternative, as shown in FIG. 8 (c), for example, there may be a configuration in which only a diesel particulate filter 34A having a catalytic function is provided, without providing exhaust purification catalysts. That is, there may be a configuration in which only a diesel particulate filter 34 is provided, which is an exhaust aftertreatment filter while acting as an exhaust aftertreatment catalyst. In any case, the present invention can be accepted as long as a configuration is contemplated having an injector for injecting an additive, such as fuel, upstream of the exhaust after-treatment catalyst and the exhaust after-treatment filter.

In the above embodiment, a catalytic converter for the decomposition (reduction) of NO _x using fuel (light oil) as a reducing agent is described as an exhaust purification catalyst for the decomposition (reduction) of NO _x . However, this is not limiting, and can be used, for example, so-called "SCR" (Selective Catalytic Reduction), wherein the NO _x in the exhaust gas is effectively adsorbed in the converter, and ammonia or urea as a reducing agent is injected from nozzle decomposition (recovery) of NO _x .

In the aforementioned embodiment, moreover, an example is provided for an explanation in which a reducing agent is added as an additive. However, it is not a limitation that the additive must be designed to be reconstituted, the additive may be, for example, fuel designed to increase the temperature through combustion while the additive is added to the exhaust system.

In addition, in the above embodiment, an example of a configuration of an intake and exhaust system having a turbocharger as a supercharger is shown. However, this is not a limitation, and, for example, providing a supercharger is not always required. Moreover, a so-called “EGR” device may be provided, which is a chilled exhaust gas recirculation device having a chilled exhaust gas recirculation path throughout the exhaust path and the intake path.

List of Reference Items

10 Exhaust cleaner

11 Engine

12 exhaust pipe (exhaust tract)

13 cylinder head

14 cylinder block

15 Hole in the cylinder block

16 piston

17 combustion chamber

18 connecting rod

19 crankshaft

20 inlet

21 Intake Manifold

22 inlet pipe

23 inlet valve

24 exhaust channel

25 exhaust manifold

26 exhaust valve

27 Turbocharger

31 fuel injector

32 oxidation chamber

33 catalytic converter

34 Diesel particulate filter

40 exhaust gas temperature sensor

41 Oxygen concentration sensor

50 nozzle

51 jet

52 front end surface

60 Mounting part

61 mounting hole

62 Cooling water path

62a Narrowed part

63 protruding part

63a Edge

65 mounting hole

70 Lock piece

75 Fastener

81 Inlet

91 Outlet

List of reference documents

Patent Document 1: JP-A-2005-214100

Patent Document 2: JP-A-2004-044483

Claims (4)

1. An exhaust cleaning device including an exhaust cleaning catalyst located in an exhaust path in communication with an engine, an injector provided upstream of an exhaust cleaning catalyst for injecting an additive into an exhaust path, and a mounting part having a mounting hole into which a nozzle is mounted, an annular cooling water path, into which cooling water is supplied, and which is provided around the mounting hole of the mounting part, the inlet tract for the cooling water inlet and the outlet a cooling water discharge path is connected to the cooling water path, and at least the inlet path extends tangentially to the cooling water path; and a narrowed portion having a water path width reduced by a protruding portion that is a protrusion of a side wall portion in a direction along the circumference of the cooling water path, and provided at a location of the cooling water path near the junction of the cooling water path and the intake path. 2. The device according to claim 1, in which the inlet tract and the exhaust path are attached to an identical position in the direction along the circumference of the cooling water path. 3. The device according to claim 1 or 2, in which the nozzle is held by the mounting part and the fixing part attached to the mounting part, and the protruding part is a bulge to which a fastener is attached to fasten the fixing part to the mounting part. 4. The device according to claim 1 or 2, in which the narrowed part is provided in the direction of the entire height of the cooling water path.

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