JP2009299544A - Exhaust emission control device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an exhaust emission control device, substantially improving catalytic efficiency, while suppressing increase in cost. <P>SOLUTION: An impactor 40 like a heated rod is disposed in an exhaust pipe 12a to stop a flow of injected additive and promote mixing of the additive with exhaust gas. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

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

  In an exhaust gas exhausted from an engine mounted on a vehicle such as an automobile, particularly a diesel engine, carbon monoxide (CO), hydrocarbon (HC), nitrogen oxide (NOx), and particulate matter (PM: Particulate Matter) is included. For this reason, generally, for example, a three-way catalyst for decomposing (reducing, etc.) the above substances, a particulate filter for capturing PM, etc. in an exhaust passage through which exhaust gas discharged from the engine passes. The exhaust gas is released into the atmosphere in a detoxified state as much as possible.

  In such a particulate filter, since PM accumulates in the filter and the passage resistance increases with use, it is necessary to perform a regeneration process as necessary. As such a regeneration process, a heating device is disposed in the particulate filter, and PM is burned and removed by heating. However, fuel (in the oxidation catalyst provided upstream of the particulate filter is added to the fuel ( There has also been proposed a method in which an exothermic reaction is caused by flowing a hydrocarbon-based liquid such as light oil and the particulate filter is regenerated by this heat (see, for example, Patent Document 1).

  In diesel engines, nitrogen oxides (NOx) are particularly likely to be generated. For this reason, in order to efficiently decompose NOx in exhaust gas, many so-called NOx trap catalysts that decompose and reduce NOx by repeatedly adsorbing and reducing NOx, for example, are often used in diesel engines. ing.

  Such a NOx trap catalyst needs to appropriately supply a reducing agent from the outside to the NOx trap catalyst in order to decompose (reduce) the adsorbed NOx. For example, there is one in which fuel (light oil) or the like is injected as a reducing agent from an injector into an exhaust manifold connected to an exhaust port of an engine and supplied to a NOx trap catalyst (see, for example, Patent Document 1).

  However, in Patent Document 1, although the injector is provided at a position away from the EGR deriving portion of the exhaust manifold, the fuel does not prevent the fuel from entering the EGR system even if the injector and the EGR deriving portion are separated. Contamination of cooler, intake manifold and intake port valve occurs. In addition to the fuel injected by the in-cylinder injector, the added fuel component in the EGR enters the cylinder, resulting in more torque than required. Further, the temperature of the exhaust manifold, the exhaust port, and the like is higher than that downstream of the turbine, and may exceed the heat resistance temperature of the exhaust injector and the injection hole deposit generation temperature.

  In addition, in order to sufficiently mix (atomize and diffuse) the reducing agent and exhaust gas, it is necessary to widen the section from the injector that injects the reducing agent to the catalyst. There is a problem that will occur.

  In order to solve such a problem, there has been proposed an ultrasonic vibration means, a heating means such as a heater, etc. provided in the exhaust pipe between the injector for injecting the reducing agent and the catalyst (for example, a patent) References 2-4).

According to the configurations of Patent Documents 2 to 4, the reducing agent injected by the ultrasonic vibration means or the heating means and the exhaust gas can be mixed efficiently.
JP 2002-21539 A JP 2008-57520 A JP 2007-71161 A JP 2006-242155 A

  However, as in Patent Documents 2 to 4, when heating means such as ultrasonic vibration means and heaters are provided in the exhaust pipe, electrical control of these ultrasonic vibration means and heating means is required, and the apparatus is There is a problem that the cost is increased due to the complexity.

  The present invention has been made in view of such circumstances. The catalyst efficiency is substantially reduced by introducing an exhaust gas in which the additive is uniformly mixed throughout the catalyst while suppressing an increase in cost. An object of the present invention is to provide an exhaust emission control device that can be improved.

  A first aspect of the present invention that solves the above problem is provided with an exhaust pipe connected to an exhaust manifold of an engine, an exhaust purification catalyst interposed in the exhaust pipe, and an upstream side of the exhaust purification catalyst. And an injector for injecting the additive into the exhaust gas, and a rod-like member whose base end is fixed to the high temperature member upstream of the injector and whose distal end is located in the injection region of the additive injected from the injector An exhaust emission control device comprising an impactor.

  In the first aspect, by providing the impactor, the tip of the impactor abuts the injected additive to divide the flow, disturb the air flow, and disturb the exhaust gas flow to add the exhaust gas. Mixing with the agent can be promoted. Further, by heating the impactor with the high temperature member on the exhaust upstream side, the atomization of the additive contacting the impactor can be promoted. In addition, heating the impactor with a high temperature member upstream of the exhaust eliminates the need for electrical control and simplifies the structure compared to providing heating means such as an ultrasonic vibration means and a heater. The increase in cost can be suppressed.

  According to a second aspect of the present invention, in the exhaust gas purification apparatus according to the first aspect, the high temperature member on the exhaust upstream side to which the base end side of the impactor is fixed is an exhaust manifold.

  In the second aspect, by fixing the impactor to the exhaust manifold and heating, the impactor can be heated to a relatively high temperature, and variation in exhaust performance from each cylinder can be prevented.

  According to a third aspect of the present invention, there is provided the exhaust purification apparatus according to the second aspect, wherein a base end portion side of the impactor is provided so as to contact the exhaust gas.

  In the third aspect, the impactor can be heated to a relatively high temperature in a short time by the exhaust gas.

  According to a fourth aspect of the present invention, in the exhaust emission control device according to any one of the first to third aspects, the impactor has a rectangular cross section.

  In the fourth aspect, the flow of the injected additive can be divided by the impactor having a rectangular cross section, and the additive contacting the impactor is bounced back so that the additive and the exhaust gas Mixing can be facilitated.

  In the present invention, the additive injected from the injector is atomized and diffused well on the upstream side of the exhaust purification catalyst and is sufficiently mixed with the exhaust gas. Can be supplied evenly. Therefore, the exhaust purification catalyst can be used effectively, and the catalyst efficiency can be substantially improved. Further, no additional heating means or the like is required, the parts cost and the structure can be simplified, and the increase in cost can be suppressed.

  Hereinafter, the present invention will be described based on an embodiment. FIG. 1 is a diagram showing a schematic configuration of an exhaust emission control device according to an embodiment, FIG. 2 is a perspective view of the main part, and FIG. 3 is a cross-sectional view of the main part.

  As shown in FIG. 1, an exhaust purification device 10 according to the present embodiment has a plurality of exhaust purification catalysts and exhaust purification filters, and the plurality of exhaust purification catalysts and exhaust purification filters are vehicles. Is installed in an exhaust pipe (exhaust passage) 12 of a multi-cylinder diesel engine (hereinafter simply referred to as an engine) 11.

  The engine 11 includes a cylinder head 13 and a cylinder block 14, and a piston 16 is accommodated in each cylinder bore 15 of the cylinder block 14 so as to be reciprocally movable. A combustion chamber 17 is formed by the piston 16, the cylinder bore 15, and the cylinder head 13. The piston 16 is connected to a crankshaft 19 via a connecting rod 18, and the crankshaft 19 is rotated by the reciprocating motion of the piston 16.

  An intake port 20 is formed in the cylinder head 13, and an intake pipe (intake passage) 22 including an intake manifold 21 is connected to the intake port 20. The intake port 20 is provided with an intake valve 23, and the intake port 20 is opened and closed by the intake valve 23. An exhaust port 24 is formed in the cylinder head 13, and an exhaust pipe (exhaust passage) 12 including an exhaust manifold 25 is connected to the exhaust port 24. The exhaust port 24 is provided with an exhaust valve 26. Like the intake port 20, the exhaust port 24 is opened and closed by the exhaust valve 26. A turbocharger 27 is provided in the middle of the intake pipe 22 and the exhaust pipe 12, and an exhaust gas purification device constituting the exhaust gas purification apparatus 10 according to the present embodiment is provided downstream of the turbocharger 27 of the exhaust pipe 12. A catalyst and an exhaust purification filter are interposed.

  The turbocharger 27 has a turbine (not shown) and a compressor connected to the turbine. When exhaust gas flows from the engine 11 into the turbocharger 27, the turbine is rotated by the flow of the exhaust gas, and the rotation of the turbine. Along with this, the compressor rotates to suck air from the intake pipe 22a into the turbocharger 27 and pressurize it. The air pressurized by the turbocharger 27 is supplied to each intake port 20 of the engine 11 through the intake pipe 22b.

  The cylinder head 13 is provided with an electronically controlled fuel injection valve 28 that directly injects fuel into the combustion chamber 17 of each cylinder. The fuel injection valve 28 has a predetermined fuel pressure from a common rail (not shown). Controlled high pressure fuel is supplied.

  Here, in the present embodiment, a diesel oxidation catalyst (hereinafter simply referred to as an oxidation catalyst) 31 and an NOx trap catalyst 32 that are exhaust purification catalysts, an exhaust purification filter, and an exhaust pipe 12 on the downstream side of the turbocharger 27. A diesel particulate filter (DPF: Diesel Particulate Filter: hereinafter referred to as DPF) 33 is arranged in order from the upstream side. As will be described in detail later, an injector 35 that injects fuel (light oil) as a reducing agent toward the oxidation catalyst 31 as an additive is provided in the exhaust pipe 12a between the turbocharger 27 and the oxidation catalyst 31. It has been.

The oxidation catalyst 31 is formed by, for example, supporting a noble metal such as platinum (Pt) or palladium (Pd) on a honeycomb structure carrier made of a ceramic material. In such an oxidation catalyst 31, when exhaust gas flows in, carbon monoxide (NO) in the exhaust gas is oxidized and nitrogen dioxide (NO ₂ ) is generated. Further, in order for the oxidation reaction in the oxidation catalyst 31 to occur, the oxidation catalyst 31 needs to be heated to a predetermined temperature or higher, and therefore the oxidation catalyst 31 may be arranged as close to the engine 11 as possible. preferable. By being arranged at a position close to the engine 11, the oxidation catalyst 31 is heated by the heat of the engine 11, and the oxidation catalyst 31 can be heated to a predetermined temperature or higher in a relatively short time even when the engine is started. it can.

In the NOx trap catalyst 32, for example, a noble metal such as platinum (Pt) or palladium (Pd) is supported on a honeycomb structure carrier made of aluminum oxide (Al ₂ O ₃ ), and barium (Ba) or the like is used as a storage agent. An alkali metal or alkaline earth metal is supported. In the NOx trap catalyst 32, NOx exhausted from the engine 11, NOx in an oxidizing atmosphere, that is, NO ₂ generated by the oxidation catalyst 31, or NO remaining in the exhaust gas without being oxidized by the oxidation catalyst 31. Is temporarily occluded and, for example, NOx is released and reduced to nitrogen (N ₂ ) or the like in a reducing atmosphere containing carbon monoxide (CO), hydrocarbon (HC), or the like.

Note that most of NOx discharged from the engine 11 and NO ₂ generated by the oxidation catalyst 31 is adsorbed / decomposed (reduced) by the NOx trap catalyst 32, and the remaining NO ₂ not adsorbed / decomposed is obtained by the DPF 33. It is purified by reaction.

  Normally, most of the exhaust gas discharged from the engine 11 is occupied by NO and the amount of HC is very small. Therefore, the inside of the NOx trap catalyst 32 becomes an oxidizing atmosphere, and the NOx trap catalyst 32 only adsorbs NOx. NOx that has been released is not decomposed (reduced). Therefore, when a predetermined amount of NOx is adsorbed on the NOx trap catalyst 32, fuel (light oil) as a reducing agent is injected from the injector 35 fixed to the exhaust pipe 12a between the turbocharger 27 and the oxidation catalyst 31. It has become so. As a result, the exhaust gas mixed with fuel passes through the oxidation catalyst 31 and is supplied to the NOx trap catalyst 32. The inside of the NOx trap catalyst 32 becomes a reducing atmosphere, and the adsorbed NOx is decomposed (reduced).

  Here, in the present invention, as shown in the figure, the injector 35 is provided in the fuel passage 12 b that communicates with the upstream exhaust pipe 12 that is not so far away from the oxidation catalyst 31. That is, the fuel passage 12b is provided so as to communicate with the exhaust pipe 12a between the turbocharger 27 and the oxidation catalyst 31, and to open toward the oxidation catalyst 31. The injector 35 is connected to the fuel passage 12b. The injection direction of the nozzle 36 is fixed on the base end side opposite to the opening on the exhaust pipe 12 a side so as to be near the center of the upstream end face of the oxidation catalyst 31. Therefore, the fuel (reducing agent) injected from the nozzle 36 of the injector 35 passes through the fuel passage 12b, is injected into the exhaust pipe 12a, and is mist while flying in the droplet state toward the center of the oxidation catalyst 31. Turn into.

  A rod-shaped impactor 40 is provided on the upstream side of the oxidation catalyst 31. The impactor 40 is made of a rod-shaped member made of a material having good heat conduction, for example, a metal material such as stainless steel, and the base end side is fixed to a high temperature member upstream of the injector 35 and the tip end side is exhausted. It arrange | positions in the injection area | region of the reducing agent (additive) injected from the injector 35 of the upstream of the oxidation catalyst 31 in the pipe | tube 12a.

  In the present embodiment, as shown in FIG. 3, a rod-shaped impactor 40 having a rectangular cross section is used, and one plane on the outer periphery of the impactor 40 is arranged toward the injector 35 side. Thereby, the fuel (reducing agent) injected from the injector 35 comes into contact with one plane on the outer periphery of the impactor 40.

  Further, the base end side of the impactor 40 is fixed to the exhaust manifold 25 which is a high temperature member on the exhaust upstream side of the injector 35. Further, in the present embodiment, as shown in FIGS. 2 and 3, the base end side of the impactor 40 is provided so as to protrude into the exhaust manifold 25 so as to contact the exhaust gas in the exhaust manifold 25. As a result, the impactor 40 is heated by the high-temperature exhaust gas in the exhaust manifold 25 and is heated to a temperature higher than the temperature of the atmosphere (exhaust gas) in the region where the fuel is injected from the injector 35.

  The tip of the impactor 40 is disposed at a position where it abuts the flow of fuel (reducing agent) injected from the injector 35 and divides the flow of injected fuel (reducing agent). That is, the impactor 40 is disposed between the injection direction of the nozzle 36 of the injector 35 and the oxidation catalyst 31 in the exhaust pipe 12a through which the exhaust gas flows, and divides the flow of fuel (reducing agent) sprayed from the injector 35. .

  As a result, the fuel (reducing agent) injected from the injector 35 comes into contact with the impactor 40 and the flow is divided, thereby mixing (atomization / diffusion) of the fuel (reducing agent) and the exhaust gas. Promoted.

  As shown in FIG. 3, the fuel (reducing agent) injected from the injector 35 abuts on the impactor 40, thereby generating a Karman vortex 41 due to the fuel downstream of the impactor 40. Further, when the exhaust gas comes into contact with the impactor 40, a Karman vortex 42 due to the exhaust gas is generated in the downstream of the impactor 40. These two Karman vortices 41 and 42 disturb the air flow between the exhaust gas and the fuel (reducing agent), thereby promoting the mixing (atomization / diffusion) of the exhaust gas and the fuel (reducing agent). The fuel (reducing agent) can be supplied uniformly to the oxidation catalyst 31.

  Further, as described above, the base end side of the impactor 40 is fixed to the exhaust manifold 25 that is a high-temperature member upstream of the exhaust, and the impactor 40 is heated by exhaust gas, so that the atmosphere (the fuel The impactor 40 can be heated to a higher temperature than the temperature of the region to be injected. Since the impactor 40 is heated to a high temperature in this manner, the rebound of the fuel (reducing agent) that collides with the impactor 40 is promoted by the Leidenfrost phenomenon, so that the mixture of the exhaust gas and the fuel (reducing agent) (atomization / diffusion) ) Can be promoted. Further, by bringing fuel (reducing agent) into contact with the heated impactor 40, fuel vaporization can be promoted and mixing (atomization / diffusion) of exhaust gas and fuel (reducing agent) can be promoted. . In this way, by promoting the mixing (atomization / diffusion) of the exhaust gas and the fuel, the fuel (reducing agent) can be supplied uniformly to the oxidation catalyst 31, and the non-reduction of the reducing agent to the oxidation catalyst 31 is prevented. The reduction of the catalyst efficiency due to the uniform supply and the reduction agent that cannot react with the oxidation catalyst 31 due to excessive supply of the reduction agent will not flow downstream.

  Further, since the reducing agent and the exhaust gas can be sufficiently mixed (atomized / diffused), it is not necessary to take a wide section between the injector 35 and the oxidation catalyst 31, and the apparatus can be downsized and the structure can be simplified. You can plan. In general, the injector 35 is provided at a considerable distance from the exhaust purification catalyst so that the injected reducing agent is sufficiently diffused and atomized before reaching the exhaust purification catalyst. This arrangement may not be possible due to restrictions. For example, in the present embodiment, the oxidation catalyst 31 is provided in the vicinity immediately below the turbocharger 27, and the exhaust pipe 12a between the turbocharger 27 and the oxidation catalyst 31 is curved in a substantially L shape. Since it is constituted by a pipe, in order to provide the injector 35 at a position separated from the oxidation catalyst 31 by a considerable distance, it is necessary to provide the fuel passage 12b. When the injector 35 is provided directly in the exhaust pipe 12a without providing such a fuel passage 12b, the reducing agent injected from the injector 35 is only in a partial region on the upstream end face of the oxidation catalyst 31 in the droplet state. It comes to adhere. However, as described above, by providing the impactor 40 that diverts the flow of the sprayed fuel (reducing agent), the exhaust gas and the fuel can be sufficiently supplied without taking a wide partition between the injector 35 and the oxidation catalyst 31. Can be mixed (atomized and diffused). Therefore, the injector 35 can be provided directly on the inner surface of the exhaust pipe 12a without providing the fuel passage 12b. Thus, by providing the injector 35 directly in the exhaust pipe 12a, it is possible to further reduce the size and the structure of the apparatus.

  In this embodiment, by providing the impactor 40 having a rectangular cross section, the mixing of exhaust gas and fuel can be further improved as compared to an impactor having a circular or elliptical cross section. . In the present embodiment, one plane on the outer periphery of the impactor 40 is arranged toward the injector 35 side. However, the position in the rotational direction around the axis of the impactor 40 is not particularly limited to this, for example The corners on the outer periphery of the impactor 40 may be arranged toward the injector 35 side.

  As described above, the impactor 40 is fixed to the exhaust manifold 25, which is a high temperature member upstream of the injector 35, so that the fuel in the injector 35 is heated to a higher temperature than the region where the fuel is injected, and the fuel and exhaust gas are exhausted. Since the mixing with the gas is improved, electrical control becomes unnecessary compared with the provision of a heating means such as an ultrasonic vibration means or a heater, and the structure can be simplified and the increase in cost can be suppressed.

  Further, since the base end side of the impactor 40 is fixed to the exhaust manifold 25, the impactor can be heated to a relatively high temperature, and the flow of the exhaust gas upstream of the exhaust manifold 25 is affected. There is nothing. That is, the impactor 40 is preferably provided on the side of the engine 11 where the temperature is as high as possible. However, if the impactor 40 is provided in any exhaust path between the exhaust port 24 and the exhaust manifold 25 provided for each cylinder. The exhaust performance between the exhaust path provided with the impactor 40 and other exhaust paths will vary. Therefore, the impactor 40 is preferably provided in the exhaust manifold 25 that is heated to a relatively high temperature and does not cause variations in exhaust performance.

  Further, since the reducing agent evenly diffused throughout the oxidation catalyst 31 is evenly mixed in the exhaust gas even after leaving the oxidation catalyst 31, it is added to the NOx trap catalyst 32, DPF 33, etc. disposed downstream. Evenly supplied.

  The DPF 33 is a filter having a honeycomb structure formed of, for example, a ceramic material. In the DPF 33, an exhaust gas passage 33a in which an upstream end is opened and a downstream end is closed and a downstream end are opened. The exhaust gas passages 33b whose upstream end portions are closed are alternately arranged. The exhaust gas first flows into the exhaust gas passage 33a with the upstream end opened, and the exhaust with the downstream end opened from the porous wall surface provided between the adjacent exhaust gas passages 33b. The gas flows into the gas passage 33b and flows downstream. In this process, the particulate matter (PM) in the exhaust gas collides with the wall surface or is adsorbed and captured.

The trapped PM is oxidized (combusted) by NO ₂ in the exhaust gas and discharged as CO ₂ , and NO ₂ remaining in the DPF 33 is decomposed into N ₂ and discharged. That is, the DPF 33 can purify the exhaust gas and greatly reduce PM and NOx emissions. Moreover, the performance of the DPF 33 is regenerated to some extent by burning PM.

Here, since NOx is normally adsorbed by the NOx trap catalyst 32 as described above, the amount of NO _{2 in} the exhaust gas supplied to the DPF 33 is small, and PM is gradually deposited on the DPF 33. When a predetermined amount of PM accumulates in the DPF 33, a predetermined amount of fuel is injected from the injector 35 fixed to the exhaust pipe 12a. As described above, when the fuel is mixed with the exhaust gas, the NOx trapped by the NOx trap catalyst 32 is reduced, so that NOx (NO ₂ ) contained in the exhaust gas is not adsorbed by the NOx trap catalyst 32. To the DPF 33. As a result, PM combustion in the DPF 33 is promoted.

  An exhaust temperature sensor 38 is provided in the vicinity of the upstream side of the oxidation catalyst 31, the NOx trap catalyst 32 and the DPF 33, and in the vicinity of the downstream side of the DPF 33, and the oxidation catalyst 31, The temperature of the exhaust gas flowing into the NOx trap catalyst 32 and the DPF 33 and the temperature of the exhaust gas discharged from the oxidation catalyst 31, the NOx trap catalyst 32 and the DPF 33 are detected. Further, an oxygen concentration sensor 39 for detecting the oxygen concentration in the exhaust gas is provided in the vicinity of the upstream side of the oxidation catalyst 31 and the DPF 33. The vehicle is provided with an electronic control unit (ECU) (not shown). The ECU includes an input / output device, a storage device for storing a control program and a control map, a central processing unit, a timer and a counter. There is a kind. The ECU performs comprehensive control of the engine 11 and the exhaust purification device 10 based on information from the sensors.

  Although one embodiment of the present invention has been described above, the present invention is not limited to the above-described embodiment. For example, in the above-described embodiment, as the exhaust purification device 10, the exhaust pipe 12 includes the oxidation catalyst 31 and the NOx trap catalyst 32, which are exhaust purification catalysts, and the DPF 33, which is an exhaust purification filter, from the upstream side. In the above example, the NOx trap catalyst 32 and the DPF 33 are arranged in this order. However, the arrangement and types of the exhaust purification catalyst and the exhaust purification filter are not particularly limited.

  In the above-described embodiment, the NOx trap catalyst that decomposes (reduces) NOx using fuel (light oil) as a reducing agent is exemplified as the exhaust gas purification catalyst that decomposes (reduces) NOx, but is not limited thereto. For example, a so-called SCR (Selective Catalytic Reduction) that selectively adsorbs NOx in exhaust gas to a catalyst and injects ammonia or urea as a reducing agent from an injector to decompose (reduce) NOx may be used.

  In the above-described embodiment, the reducing agent is used as the additive. However, the reducing agent is not limited to the purpose of reducing action, and if it is added to the exhaust system, for example, the purpose is to raise the temperature by combustion. Fuel that has been used may be used.

  Furthermore, in the above-described embodiment, an example of the configuration of an intake / exhaust system including a turbocharger as a supercharger is shown. However, the present invention is not particularly limited thereto. For example, the supercharger is not necessarily provided. In the above-described embodiment, the cooling exhaust gas recirculation device having a cooling exhaust gas recirculation path between the exhaust passage and the intake passage, ie, a so-called EGR device is exemplified. Is not necessarily provided.

  In the above-described embodiment, the base end side of the impactor 40 is fixed to the exhaust manifold 25, and the impactor 40 is heated by the exhaust gas flowing through the exhaust manifold 25. However, the member that fixes the impactor 40 is particularly The present invention is not limited to this, and any location may be used as long as it is a high temperature portion upstream of the exhaust gas from the region where the fuel of the injector 35 is injected. Examples of the high temperature portion upstream of the exhaust gas include the cylinder head 13 and the turbocharger 27 in addition to the exhaust manifold 25 described above. In particular, the impactor 40 is fixed to a member constituting the engine 11, for example, the exhaust manifold 25 or the cylinder head 13 described above, so that the impactor 40 is heated to a high temperature by the heat of the exhaust gas and the heat of the engine 11 itself. Is preferable. Further, in the above-described embodiment, the impactor 40 is heated by the exhaust gas by bringing the base end side of the impactor 40 into contact with the exhaust gas. However, the present invention is not particularly limited to this. For example, the base of the impactor 40 You may make it fix an edge part side to the outer periphery of a high temperature member.

  Furthermore, in the above-described embodiment, the rod-shaped impactor 40 having a rectangular cross section is illustrated. However, the shape of the impactor 40 is not particularly limited to this, for example, a rod-shaped cross section having a circular shape or an elliptical shape. It may be a member.

  Further, a plurality of plate-like fins may be provided on the base end side of the impactor 40, and the surface area of the impactor 40 heated by the exhaust gas may be increased to improve the efficiency of heating the impactor by the exhaust gas. .

  Of course, the number of impactors 40 is not particularly limited, and may be two or more.

  The present invention can be used in the industrial field of exhaust purification devices that remove (delete) harmful substances from exhaust gas.

1 is a schematic configuration diagram of an exhaust emission control device according to an embodiment. It is a perspective view which shows the principal part of the exhaust gas purification apparatus which concerns on one Embodiment. It is sectional drawing which shows the principal part of the exhaust gas purification apparatus which concerns on one Embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Exhaust purification apparatus 11 Engine 12, 12a Exhaust pipe 12b Fuel passage 24 Exhaust port 25 Exhaust manifold 26 Exhaust valve 27 Turbocharger 28 Fuel injection valve 31 Oxidation catalyst 32 NOx trap catalyst 33 DPF
35 Injector 36 Nozzle 40 Impactor

Claims (4)

  An exhaust pipe connected to an exhaust manifold of the engine, an exhaust purification catalyst interposed in the exhaust pipe, an injector provided upstream of the exhaust purification catalyst and injecting an additive into the exhaust gas; An exhaust gas purification apparatus comprising: a rod-shaped impactor having a proximal end portion fixed to a high temperature member on an upstream side of an exhaust of an injector and a distal end portion positioned in an injection region of an additive injected from the injector.   The exhaust emission control device according to claim 1, wherein the exhaust upstream high temperature member to which the base end side of the impactor is fixed is an exhaust manifold.   The exhaust emission control device according to claim 2, wherein a base end portion side of the impactor is provided so as to come into contact with the exhaust gas.   The exhaust purifier according to any one of claims 1 to 3, wherein the impactor has a rectangular cross section.

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