JP2012107634A - Exhaust emission control device of internal combustion engine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an exhaust emission control device of an internal combustion engine that is superior in ignition performance and combustion stability.SOLUTION: The exhaust emission control device includes: an exhaust pipe 12 having a wall; an oxidation catalyst 13 purifying exhaust gas; a fuel addition valve 15 arranged upstream the oxidation catalyst 13 on the exhaust pipe 12 and for injecting fuel into the exhaust pipe 12; and a glow plug 51 having a heat generation part 51a arranged inside the exhaust pipe 12 and for igniting the fuel injected from the fuel addition valve 15. The wall has a recess 12a projecting outward the exhaust pipe 12. The recess 12a has an outside dimension with which screens the whole of the heat generation part 51a when the exhaust pipe 12 is viewed from the upstream.

Description

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

In an internal combustion engine such as a diesel engine or a gasoline engine, fuel is burned in the engine body, and exhaust gas containing pollutants is discharged. The harmful contaminants, e.g., carbon monoxide (CO), unburnt hydrocarbons (HC), nitrogen oxides (NO _X) or particulate (PM), and the like.

An exhaust treatment device is attached to the internal combustion engine to purify the exhaust gas. The exhaust treatment device includes an oxidation catalyst for oxidizing carbon monoxide, NO _X storage catalyst for removing nitrogen oxides, such as a particulate filter for removing particulates (particulate matter) is . The exhaust treatment apparatus has operating conditions such as temperature for performing each function.

  Japanese Patent Laid-Open No. 2006-112401 discloses a catalyst temperature raising device for raising the temperature of a catalyst for purifying engine exhaust gas at an early stage. This catalyst temperature raising device has an addition valve having an injection port for injecting fuel upstream of the catalyst carrier in the exhaust gas flow path, and an ignition means having a heat generating part for igniting the fuel. ing. It is disclosed that the addition valve and the ignition means are disposed at a position where the fuel injected from the injection port directly contacts the heat generating portion.

JP 2006-112401 A

  In some cases, it is preferable to raise the temperature of the exhaust treatment device disposed in the exhaust gas purification device of the internal combustion engine early. For example, an oxidation catalyst has an activation temperature for causing an oxidation reaction, and it is preferable that the temperature can be raised to this activation temperature early. As in the apparatus disclosed in the above publication, the temperature of the oxidation catalyst can be raised in a short time by injecting and burning fuel upstream of the oxidation catalyst.

  Here, exhaust gas flowing out from the engine body flows through the engine exhaust passage in which an exhaust treatment device such as an oxidation catalyst is disposed. When it is attempted to generate a flame by igniting the fuel injected into the engine exhaust passage, there are cases where ignition cannot be performed in the engine exhaust passage due to the state of the exhaust gas flowing through the engine exhaust passage. For example, if the flow rate of exhaust gas in the engine exhaust passage is large under conditions of a predetermined temperature and a predetermined oxygen concentration in the engine exhaust passage, the fuel injected into the engine exhaust passage may not be ignited. . Furthermore, even if a flame is generated by ignition, combustion may become unstable. When the fuel injected into the engine exhaust passage is not ignited or the combustion is unstable, there is a problem that exhaust gas containing a lot of unburned fuel is discharged into the atmosphere.

  An object of the present invention is to provide an exhaust emission control device for an internal combustion engine that excels in ignition performance and combustion stability in an exhaust emission control device that burns fuel in an engine exhaust passage.

  The exhaust gas purification apparatus for an internal combustion engine according to the first aspect of the present invention has a wall portion, an exhaust pipe that forms at least a part of the engine exhaust passage, and an exhaust treatment that is disposed in the engine exhaust passage and purifies the exhaust gas. A fuel supply means for injecting fuel into the engine exhaust passage, and a heat generating portion disposed inside the engine exhaust passage; Ignition means for igniting the fuel injected from the fuel supply means. The wall portion has a deformed portion protruding toward either the inside or the outside of the exhaust pipe, and the deformed portion has an outer dimension that hides the entire heat generating portion when the engine exhaust passage is viewed from the upstream side. . With this configuration, ignition performance and combustion stability can be improved.

  In the above invention, the deforming portion is disposed on the upstream side of the igniting means at a distance from the igniting means, and includes a protruding portion protruding inside the exhaust pipe, and the protruding portion blocks a part of the engine exhaust passage. It is preferable. Or it is preferable that a deformation | transformation part contains the recessed part which protrudes the outer side of an exhaust pipe, and the ignition part has the heat-emitting part arrange | positioned inside a recessed part.

  An exhaust purification device for an internal combustion engine according to a second aspect of the present invention is disposed in the engine exhaust passage and is disposed upstream of the exhaust treatment device in the engine exhaust passage. An ignition means having an ascending heat generation part and a fuel supply means arranged upstream of the ignition means and injecting fuel toward the heat generation part, the fuel supply means and the ignition means directly collide with the heat generation part The fuel passing through the side of the heat generating portion without being reflected is arranged so as to be reflected by the wall portion of the engine exhaust passage and directed toward the heat generating portion. With this configuration, ignition performance and combustion stability can be improved.

  An exhaust gas purification apparatus for an internal combustion engine according to a third aspect of the present invention is disposed in an engine exhaust passage, purifies exhaust gas, and is disposed upstream of the exhaust treatment apparatus in the engine exhaust passage. An engine comprising: fuel supply means for injecting fuel into the passage; and an ignition means for igniting the fuel injected from the fuel supply means, having a heat generating portion disposed inside the engine exhaust passage. An inhibiting member that blocks a part of the exhaust passage and reduces the flow rate of the exhaust gas that collides with the heat generating portion is disposed upstream of the ignition means and spaced from the ignition means. With this configuration, ignition performance and combustion stability can be improved.

  In the above invention, it is preferable that the inhibiting member has an outer dimension that hides the entire heat generating portion when the engine exhaust passage is viewed from the upstream side. With this configuration, the flow of exhaust gas can be effectively inhibited.

  An exhaust gas purification device for an internal combustion engine according to a fourth aspect of the present invention is disposed in the engine exhaust passage, and is disposed upstream of the exhaust treatment device in the engine exhaust passage, An ignition means having an ascending heat generating part and a fuel supply means arranged on the upstream side of the ignition means and injecting fuel toward the heat generating part are provided, and the side of the heat generating part is disposed without colliding directly with the heat generating part. A fuel reflector that captures the passing fuel and reflects it toward the heat generating portion is disposed in the engine exhaust passage corresponding to the fuel injection direction. With this configuration, ignition performance and combustion stability can be improved.

  In the said invention, it is preferable that a fuel reflector has a reflective surface which reflects a fuel, and is arrange | positioned so that a reflective surface may oppose a heat generating part. With this configuration, the fuel can be effectively reflected.

  ADVANTAGE OF THE INVENTION According to this invention, the exhaust gas purification apparatus which burns a fuel in an engine exhaust passage can provide the exhaust gas purification apparatus of the internal combustion engine excellent in ignition performance and combustion stability.

1 is an overall view of a compression ignition type internal combustion engine. 2 is a schematic cross-sectional view of a portion of an exhaust pipe of the first exhaust purification device in Embodiment 1. FIG. It is a graph which shows the ignition area | region of the fuel supplied from a fuel supply valve. 2 is a schematic perspective view of a fuel supply valve, a glow plug, and a plate-like member of the first exhaust purification device in Embodiment 1. FIG. FIG. 5 is a schematic perspective view of a fuel supply valve, a glow plug, and a plate-like member of the second exhaust purification device in the first embodiment. FIG. 5 is a schematic front view of a glow plug and a plate-like member of the second exhaust purification device in the first embodiment. FIG. 5 is a schematic perspective view of a fuel supply valve, a glow plug, and a plate-like member of the third exhaust purification device in the first embodiment. FIG. 5 is a schematic front view of a glow plug and a plate-like member of a third exhaust purification device in the first embodiment. 6 is a schematic perspective view of a fuel supply valve, a glow plug, and a plate-like member of a fourth exhaust purification device in Embodiment 1. FIG. 6 is a schematic cross-sectional view of a portion of an exhaust pipe of a fifth exhaust purification device in Embodiment 1. FIG. 6 is a schematic cross-sectional view of a portion of an exhaust pipe of a first exhaust purification device in Embodiment 2. FIG. 6 is a schematic perspective view of a glow plug and a plate-like member of a first exhaust purification device in Embodiment 2. FIG. FIG. 6 is a schematic front view of a glow plug and a plate-like member of a first exhaust purification device in a second embodiment. FIG. 6 is a schematic cross-sectional view of a portion of an exhaust pipe of a second exhaust purification device in a second embodiment. 6 is a schematic cross-sectional view of a portion of an exhaust pipe of a third exhaust purification device in Embodiment 2. FIG. 6 is a schematic cross-sectional view of a portion of an exhaust pipe of a fourth exhaust purification device in Embodiment 2. FIG. FIG. 6 is a schematic cross-sectional view of an exhaust pipe portion of an exhaust purification device in a third embodiment. FIG. 6 is a schematic perspective view of a fuel supply valve, a glow plug, and a plate-like member of an exhaust purification apparatus according to Embodiment 3.

(Embodiment 1)
With reference to FIG. 1 to FIG. 10, an exhaust gas purification apparatus for an internal combustion engine in the first embodiment will be described.

  FIG. 1 shows an overall view of a compression ignition type internal combustion engine in the present embodiment. In this internal combustion engine, the first exhaust gas purification device in the present embodiment is arranged. In the present embodiment, a diesel engine will be described as an example. The internal combustion engine includes an engine body 1. The engine body 1 includes a combustion chamber 2 for each cylinder, an electronically controlled fuel injection valve 3 for injecting fuel into each combustion chamber 2, an intake manifold 4, and an exhaust manifold 5.

  The intake manifold 4 is connected to the outlet of the compressor 7 a of the exhaust turbocharger 7 via the intake duct 6. An inlet of the compressor 7 a is connected to an air cleaner 9 via an intake air amount detector 8. A throttle valve 10 driven by a step motor is disposed in the intake duct 6, and a cooling device 11 for cooling intake air flowing through the intake duct 6 is disposed around the intake duct 6. In the embodiment shown in FIG. 1, the engine cooling water is guided into the cooling device 11, and the intake air is cooled by the engine cooling water.

On the other hand, the exhaust manifold 5 is connected to the inlet of the exhaust turbine 7 b of the exhaust turbocharger 7. An outlet of the exhaust turbine 7b is connected to an oxidation catalyst 13 as an exhaust purification catalyst via an exhaust pipe 12. A particulate filter 16 for collecting particulates in the exhaust gas is disposed in the engine exhaust passage downstream of the oxidation catalyst 13. Further, in the embodiment shown in FIG. 1, the NO _X storage catalyst 17 is arranged in the engine exhaust passage downstream of the particulate filter 16. These oxidation catalysts 13, particulate filter 16 and _the NO _X storage catalyst 17 functions as an exhaust processing device that functions to purify exhaust.

  A fuel supply valve 15 is disposed in the engine exhaust passage upstream of the oxidation catalyst 13, that is, in the exhaust pipe 12 as fuel supply means for supplying fuel into the exhaust pipe 12. The fuel supply valve 15 is formed to have a fuel supply action of supplying or stopping fuel. A glow plug 51 is disposed between the fuel supply valve 15 and the oxidation catalyst 13. The glow plug 51 is formed so that the surroundings can be heated and stopped. The glow plug 51 functions as an ignition means for igniting the fuel injected from the fuel supply valve 15.

  An EGR passage 18 is arranged between the exhaust manifold 5 and the intake manifold 4 for exhaust gas recirculation (EGR). An electronically controlled EGR control valve 19 is disposed in the EGR passage 18. A cooling device 20 for cooling the EGR gas flowing in the EGR passage 18 is disposed around the EGR passage 18. In the embodiment shown in FIG. 1, the engine cooling water is guided into the cooling device 20, and the EGR gas is cooled by the engine cooling water.

  Each fuel injection valve 3 is connected to a common rail 22 via a fuel supply pipe 21. The common rail 22 is connected to a fuel tank 24 via an electronically controlled fuel pump 23 having a variable discharge amount. The fuel stored in the fuel tank 24 is supplied into the common rail 22 by the fuel pump 23. The fuel supplied into the common rail 22 is supplied to the fuel injection valve 3 through each fuel supply pipe 21.

  The electronic control unit 30 is composed of a digital computer. The electronic control unit 30 in the present embodiment functions as a control unit of the exhaust purification device. The electronic control unit 30 includes a ROM (Read Only Memory) 32, a RAM (Random Access Memory) 33, a CPU (Microprocessor) 34, an input port 35, and an output port 36 connected to each other by a bidirectional bus 31.

A temperature sensor 26 for detecting the temperature of the oxidation catalyst 13 or the particulate filter 16 is disposed downstream of the particulate filter 16. Temperature sensor 27 for detecting the temperature of the NO _X NO _X storage catalyst 17 downstream of the storage catalyst 17 is arranged. The output signals of these temperature sensors 26 and 27 are input to the input port 35 via the corresponding AD converter 37.

  The particulate filter 16 is provided with a differential pressure sensor 28 for detecting the differential pressure across the particulate filter 16. Output signals of the differential pressure sensor 28 and the intake air amount detector 8 are input to the input port 35 via the corresponding AD converters 37. Connected to the accelerator pedal 40 is a load sensor 41 that generates an output voltage proportional to the depression amount L of the accelerator pedal 40. The output voltage of the load sensor 41 is input to the input port 35 via the corresponding AD converter 37. Further, the input port 35 is connected to a crank angle sensor 42 that generates an output pulse every time the crankshaft rotates, for example, 15 °. On the other hand, the output port 36 is connected to the fuel injection valve 3, the step motor for driving the throttle valve 10, the EGR control valve 19, and the fuel pump 23 through corresponding drive circuits 38. Further, the output port 36 is connected to the fuel supply valve 15 and the glow plug 51 via a corresponding drive circuit 38. The fuel supply valve 15 and the glow plug 51 in the present embodiment are controlled by the electronic control unit 30.

  FIG. 2 is a schematic cross-sectional view of an exhaust pipe in which a fuel supply valve and a glow plug of the first exhaust purification apparatus of the present embodiment are arranged. The exhaust pipe 12 is formed in a cylindrical shape. The exhaust pipe 12 in the present embodiment is formed in a straight line. The fuel supply valve 15 is arranged on the upstream side of the oxidation catalyst 13 and the glow plug 51. The glow plug 51 is disposed between the fuel supply valve 15 and the oxidation catalyst 13.

  The fuel supply valve 15 in the present embodiment has an injection port so as to inject the fuel radially. The fuel is injected so as to expand toward the downstream. The exhaust emission control device in the present embodiment is formed such that light oil, which is the fuel of the engine body 1, is injected from the fuel supply valve 15. About fuel, it is not restricted to this form, The fuel different from the fuel of an engine main body may be supplied.

  The glow plug 51 is disposed so as to heat the fuel supplied from the fuel supply valve 15. The glow plug 51 has a heat generating portion 51a that increases in temperature. The heat generating portion 51 a in this device example is formed at the tip of the glow plug 51. The heat generating portion is a portion that generates heat up to a temperature at which the fuel can be ignited. In the example shown in FIG. 2, the portion where the diameter of the tip of the glow plug 51 becomes small is the heat generating portion 51 a. The entirety of the heat generating portion 51 a is disposed inside the exhaust pipe 12. Note that the heat generating portion may not be disposed at the tip of the ignition means.

  The fuel supply valve 15 is formed so as to inject fuel toward the heat generating portion 51a. The injection port of the fuel supply valve 15 faces the heat generating part 51 a of the glow plug 51. The glow plug 51 is disposed at a position where the heat generating portion 51 a comes into contact with the fuel injected from the fuel supply valve 15.

  The glow plug 51 and the fuel supply valve 15 in the present embodiment are each formed in a rod shape. The glow plug 51 and the fuel supply valve 15 are inserted into the exhaust pipe 12 from one of the circumferential directions of the exhaust pipe 12. The glow plug 51 and the fuel supply valve 15 can be of any shape. Further, each of the glow plug 51 and the fuel supply valve 15 may be disposed in any direction in the circumferential direction of the exhaust pipe 12.

  The oxidation catalyst 13 is a catalyst having oxidation ability for purifying exhaust gas. The oxidation catalyst 13 includes, for example, a base body having a partition wall extending in the exhaust gas flow direction inside a cylindrical case body. The substrate is formed in a honeycomb structure, for example. A coating layer made of, for example, porous oxide powder is formed on the surface of the substrate, and a noble metal catalyst such as platinum Pt is supported on the coating layer.

  The exhaust gas purification apparatus for an internal combustion engine according to the present embodiment can generate a flame by heating the fuel injected from the fuel supply valve 15 by the glow plug 51. Here, depending on the atmosphere inside the exhaust pipe 12, there are cases where a flame can be generated and when it cannot be generated. That is, depending on the state of the exhaust gas discharged from the engine body, there are an operation region in which fuel can be ignited and an operation region in which ignition is not possible. Whether or not a flame can be generated depends on, for example, the oxygen concentration of the exhaust gas and the flow rate of the exhaust gas.

  FIG. 3 shows a graph for explaining the range in which the fuel injected from the fuel supply valve ignites. The horizontal axis is the oxygen concentration of the exhaust gas, and the vertical axis is the flow rate of the exhaust gas. With respect to the oxygen concentration of the exhaust gas, ignition can be performed when the exhaust gas concentration is higher than the ignitable concentration. Further, ignition is easier as the oxygen concentration of the exhaust gas is higher. As for the flow rate of the exhaust gas, the smaller the flow rate, the easier the ignition. On the other hand, the ignition becomes unstable when the flow rate of the exhaust gas is large. Or fuel combustion becomes unstable. As shown in FIG. 3, a region where ignition is possible is defined. In addition, among the regions that can be ignited, regions that are easy to ignite are classified.

  FIG. 4 is a schematic perspective view of the fuel supply valve, the glow plug, and the plate-like member of the first exhaust purification device in the present embodiment. Referring to FIGS. 2 and 4, the exhaust emission control device according to the present embodiment passes the side of heat generating portion 51 a without directly colliding with heat generating portion 51 a of the fuel injected from fuel supply valve 15. A plate-like member 52 that captures the fuel and reflects the fuel toward the heat generating portion 51a is provided. The plate-like member 52 functions as a fuel reflector that changes the traveling direction of the fuel. The plate-like member 52 is disposed inside the exhaust pipe 12 corresponding to the fuel injection direction from the fuel supply valve 15. That is, the plate-like member 52 is disposed in the exhaust pipe 12 at a position where the injected fuel collides.

  The plate member 52 is formed in a flat plate shape. The plate-like member 52 has a reflecting surface 52a that reflects the fuel. In the present embodiment, the main surface of the plate-like member 52 is the reflecting surface 52a. The plate-like member 52 is disposed so that the reflection surface 52a faces the heat generating portion 51a. The plate member 52 is disposed between the heat generating part 51 a and the wall part of the exhaust pipe 12. The plate-like member 52 is disposed so that the reflecting surface 52 a is substantially parallel to the exhaust gas flow direction indicated by the arrow 90. The glow plug 51 is inserted from one of the circumferential directions of the exhaust pipe 12, and the plate-like member 52 is disposed so that the reflection surface 52a is substantially perpendicular to the one direction. The plate-like member 52 has a square planar shape, but is not limited to this form, and any planar shape can be adopted.

  Referring to FIG. 4, the exhaust emission control device in the present embodiment includes a support member 59 that supports plate-like member 52. The support member 59 is fixed to the exhaust pipe 12. The support of the plate-like member 52 is not limited to this form, and can be supported on the exhaust pipe by any configuration. For example, a part of the plate-like member may be extended and this extended part may be fixed to the exhaust pipe.

  Referring to FIGS. 1, 2 and 4, when the internal combustion engine is driven, exhaust gas is discharged from engine body 1 toward the engine exhaust passage. The exhaust gas flows along the direction in which the exhaust pipe 12 extends, as indicated by an arrow 90. In the present embodiment, the exhaust gas flows linearly inside the exhaust pipe 12.

  Part of the fuel injected from the fuel supply valve 15 directly collides with the heat generating part 51 a toward the heat generating part 51 a of the glow plug 51. The other part of the fuel deviates from the direction toward the heat generating part 51a and goes to the side of the heat generating part 51a. In the present embodiment, as indicated by an arrow 91, the fuel passing through the side of the heat generating portion 51a can be captured by the plate-like member 52 and reflected toward the heat generating portion 51a. In particular, the fuel that reaches the side of the heat generating portion 51a in the flow direction of the exhaust gas can be reflected and directed to the heat generating portion 51a. That is, the fuel passing through the upstream side of the heat generating part 51a can be reflected and directed to the heat generating part 51a. For this reason, a large amount of fuel can be collected in the heat generating part 51a, and the ignition performance of the fuel can be improved. The fuel can be ignited in a wider temperature range, a wider exhaust gas flow velocity range, or a wider exhaust gas oxygen concentration range. Moreover, the combustion of the ignited fuel can be stabilized. That is, it can suppress that it extinguishes during combustion.

  The plate member 52 is formed so that the reflection surface 52a faces the heat generating portion 51a. With this configuration, a large amount of fuel can be reflected. The plate-like member 52 is disposed so as to be substantially parallel to the exhaust gas flow direction. With this configuration, when the plate-like member 52 is disposed inside the exhaust pipe 12, it is possible to suppress a reduction in the exhaust gas flow passage cross-sectional area. The arrangement of the plate-like members is not limited to this form, and may be arranged so as to be inclined with respect to the flow direction of the exhaust gas, for example. Further, a through hole for allowing the exhaust gas to flow through the plate-like member may be formed.

  The exhaust emission control device in the present embodiment can perform stable combustion over a wide operating range, and can quickly raise the temperature of the exhaust treatment device arranged downstream of the glow plug. When the exhaust treatment device is the oxidation catalyst 13 as in the device example shown in FIG. 2, the temperature of the oxidation catalyst 13 can be raised quickly. When the oxidation catalyst is lower than the activation temperature, it can be quickly brought to the activation temperature or higher, and the exhaust gas can be treated. In addition, the oxidation capability of the oxidation catalyst improves as the temperature increases even when the activation temperature is higher than the activation temperature. For this reason, when the oxidation catalyst is equal to or higher than the oxidation activation temperature, the treatment capacity of the oxidation catalyst can be improved in a short time by generating a flame and quickly raising the temperature. Or when the oxidation catalyst arrange | positioned downstream of a glow plug is an inactive state, it can suppress that unburned fuel is discharge | released in air | atmosphere.

When the exhaust treatment device arranged downstream of the glow plug is a particulate filter, the temperature can be raised in a short time in order to burn the accumulated particulates. In the case where the exhaust treatment device is a NO _X storage catalyst, the temperature can be raised in a short time in order to release SO _X accumulated together with NO _X. As in the apparatus example of Figure 1, if the particulate filter 16 or NO _X upstream oxidation catalyst 13 of the occlusion catalyst 17 is disposed, to the exhaust gas to a high temperature by increasing the temperature of the oxidation catalyst 13 and it is, by the exhaust gas can be heated particulate filter 16 or the NO _X storing catalyst 17. Further, when an exhaust treatment device that requires a reducing agent is disposed downstream of the glow plug, a light reducing agent such as unburned hydrocarbon is supplied to the exhaust treatment device by improving combustion stability. be able to.

  The fuel supply valve in the present embodiment is controlled to inject fuel intermittently. By intermittently injecting fuel, air can be interposed between the supplied fuels. That is, the fuel supplied intermittently comes into contact with a lot of air and burns. As a result, the combustion characteristics are improved and the flame temperature can be increased. Alternatively, unburned fuel can be burned. The supply of fuel from the fuel supply valve is not limited to this form, and it may be controlled to inject fuel continuously.

  FIG. 5 shows a schematic perspective view of the fuel supply valve, the glow plug, and the plate-like member of the second exhaust purification apparatus in the present embodiment. FIG. 6 shows a schematic front view of the glow plug and the plate-like member of the second exhaust purification device in the present embodiment. The second exhaust purification device includes a plate-like member 53. The plate-like member 53 has a curved shape. The plate-like member 53 has a recessed shape and has a reflective surface 53a on the inner side. The reflective surface 53a faces the heat generating portion 51a. The plate-like member 53 is disposed so that the reflecting surface 53a is substantially parallel to the exhaust gas flow direction. As the curved shape, for example, the cross-sectional shape can be formed in a parabolic shape or an arc shape.

  Since the plate-like member 53 is curved, as shown by an arrow 92, the fuel deviating from the heat generating part 51a can be reflected toward the heat generating part 51a. For this reason, a lot of fuel can be collected in the heat generating part 51a. In particular, the fuel that reaches the side of the heat generating portion 51a in the direction perpendicular to the flow direction of the exhaust gas can be collected in the heat generating portion 51a.

  FIG. 7 shows a schematic perspective view of the fuel supply valve, the glow plug, and the plate-like member of the third exhaust purification apparatus in the present embodiment. FIG. 8 shows a schematic front view of a glow plug and a plate-like member of the third exhaust purification apparatus in the present embodiment. The third exhaust purification device includes a plate-like member 54.

  The plate member 54 is formed in a flat plate shape. The plate-like member 54 is arranged so that the reflection surface 54a is substantially parallel to the flow direction of the exhaust gas. Further, the plate-like member 54 is disposed so that the reflection surface 54a is substantially parallel to the direction in which the glow plug 51 is inserted. The plate-like member 54 is disposed on both sides of the glow plug 51 so as to sandwich the glow plug 51. The reflective surface 54a faces the heat generating portion 51a.

  Referring to FIG. 8, the plate-like member 54 is arranged, and as shown by an arrow 93, the fuel passing through the side of the heat generating portion 51a is reflected by the reflecting surface 54a of the plate-like member 54 to generate heat. It can be directed to the part 51a. For this reason, a lot of fuel can be collected in the heat generating part 51a. In particular, the fuel that reaches the side of the heat generating portion 51a in the direction perpendicular to the flow direction of the exhaust gas can be collected in the heat generating portion 51a.

  FIG. 9 shows a schematic perspective view of the fuel supply valve, the glow plug, and the plate-like member of the fourth exhaust purification apparatus in the present embodiment. The fourth exhaust purification device includes a plate-like member 55. The plate-like member 55 has a U-shaped cross section. The plate-like member 55 has a flat plate portion 55a and a curved portion 55b. The plate-like member 55 has a shape obtained by combining the plate-like member 53 of the second exhaust purification device and the plate-like member 54 of the third exhaust purification device in the present embodiment. By adopting the plate-like member 55, the fuel passing through the side of the heat generating part 51a in the exhaust gas flow direction and the fuel passing through the side of the heat generating part 51a in the direction perpendicular to the exhaust gas flowing direction are used. It can be reflected and collected in the heat generating part 51a.

  The fuel reflection plate is not limited to the above-described form, and may be formed so as to reflect the fuel passing through the side of the heat generating portion and direct it toward the heat generating portion. In the present embodiment, some of the fuel passing through the side of the heat generating part is reflected. However, the present invention is not limited to this, and all the fuel passing through the side of the heat generating part is reflected. Then, it may be formed so as to face the heat generating portion.

  Next, with reference to FIG. 10, the 5th exhaust gas purification apparatus in this Embodiment is demonstrated. FIG. 10 is a schematic cross-sectional view of an exhaust pipe in which a fuel supply valve and a glow plug of the fifth exhaust purification apparatus are arranged. The fuel supply valve 15 and the glow plug 51 are inserted from one of the circumferential directions of the exhaust pipe 12. That is, the fuel supply valve 15 and the glow plug 51 are arranged in the same direction in the circumferential direction of the exhaust pipe 12.

  The fifth exhaust purification device reflects the fuel that passes through the side of the heat generating part 51a without directly colliding with the heat generating part 51a out of the fuel injected from the fuel supply valve 15 by the wall part of the exhaust pipe 12. And is formed so as to face the heat generating portion 51a. In this example of the apparatus, the glow plug 51 and the fuel supply valve 15 are separated from each other so that a part of the fuel is reflected by the wall portion of the exhaust pipe 12 and travels toward the heat generating portion 51a.

  A part of the fuel injected from the fuel supply valve 15 is reflected by the wall portion of the exhaust pipe 12 and proceeds toward the heat generating portion 51a as indicated by an arrow 94. As a result, a large amount of fuel can be collected around the heat generating portion 51a, and the ignition performance and combustion stability are improved.

  The arrangement of the glow plug 51 and the fuel supply valve 15 is not limited as long as the fuel is reflected by the wall portion of the exhaust pipe 12 and directed toward the heat generating portion 51a. For example, even if the heat generating part 51a is inserted to the vicinity of the wall part opposite to the direction in which the glow plug 51 is inserted, and the fuel reflected by the wall part of the exhaust pipe 12 is directed to the heat generating part 51a. I do not care.

  The fuel supply valve in the present embodiment is formed so that the injection port faces the heat generating part of the glow plug, but the injection port of the fuel supply valve is formed to face in a different direction from the heat generating part of the glow plug. be able to. For example, the injection port of the fuel supply valve can be formed so as to face the wall portion of the opposing engine exhaust passage.

  In the present embodiment, a fuel supply valve that injects fuel is employed as the fuel supply means. However, the present invention is not limited to this form, and the fuel supply means is formed so as to supply fuel into the engine exhaust passage. It doesn't matter if it is.

  In the present embodiment, a glow plug is employed as the ignition means, but the present invention is not limited to this configuration, and any device capable of igniting the supplied fuel can be employed. For example, a spark plug or a ceramic heater may be employed as the ignition means.

The exhaust treatment device of the present embodiment, an oxidation catalyst, has been described by taking as an example _the NO _X storage catalyst and the particulate filter, but the invention is not limited to this, the present invention to any device for purifying exhaust Can be applied. Moreover, you may arrange | position each exhaust processing apparatus individually or in combination.

  In the present embodiment, a diesel engine has been described as an example of an internal combustion engine. However, the present invention is not limited to this embodiment, and the present invention can be applied to an exhaust gas purification apparatus for an arbitrary internal combustion engine.

(Embodiment 2)
With reference to FIGS. 11 to 16, an exhaust emission control device for an internal combustion engine in the second embodiment will be described.

  FIG. 11 is a schematic cross-sectional view of a portion of the exhaust pipe of the first exhaust purification device in the present embodiment. The first exhaust gas purification apparatus in the present embodiment includes an obstruction member that is disposed on the upstream side of the glow plug 51 at a distance from the glow plug 51.

  In the first exhaust purification device, a plate-like member 56 is disposed as an obstructing member inside the exhaust pipe 12. The plate member 56 is formed in a flat plate shape. The plate-like member 56 is disposed in a part of the cross section of the engine exhaust passage. The plate-like member 56 blocks a part of the engine exhaust passage. An exhaust passage is formed around the plate member 56. The plate member 56 is disposed between the fuel supply valve 15 and the glow plug 51. In the glow plug 51, the entire heat generating portion 51 a is disposed inside the exhaust pipe 12. Note that the glow plug may have a part of the heat generating portion disposed inside the exhaust pipe.

  FIG. 12 shows a schematic perspective view of a glow plug and a plate-like member of the first exhaust purification device in the present embodiment. FIG. 13 shows a schematic front view of the glow plug and the plate member when the engine exhaust passage is viewed from the upstream side. The plate member 56 is supported on the exhaust pipe 12 by a support member 59.

  The plate-like member 56 has an obstruction surface 56a that inhibits the flow of exhaust gas. The plate-like member 56 is disposed so that the obstructing surface 56 a is substantially perpendicular to the exhaust gas flow direction indicated by the arrow 90. The plate-like member 56 is close to the glow plug 51 so as to inhibit the flow of exhaust gas from the heat generating portion 51a of the glow plug 51. The plate-like member 56 is disposed away from the glow plug 51 so that air can be taken from the exhaust gas when the injected fuel burns.

  Referring to FIG. 13, the plate-like member 56 is arranged so that the entire heat generating portion 51 a is included in the projection area when the plate-like member 56 is projected toward the heat generating portion 51 a of the glow plug 51. ing. That is, the plate-like member 56 has an outer dimension such that the entire heat generating portion 51 a is hidden by the plate-like member 56 when viewed from the upstream side of the engine exhaust passage.

  By disposing the plate-like member 56 as an inhibiting member on the upstream side of the heat generating part 51a of the glow plug 51, the flow of exhaust gas that collides with the heat generating part 51a can be inhibited. The speed when the exhaust gas collides with the heat generating portion 51a can be reduced. For this reason, it can suppress that the heat-emitting part 51a is cooled by exhaust gas, and can raise the temperature of the heat-generating part 51a. As a result, the ignition performance in the heat generating part 51a of the glow plug 51 can be improved. Or, combustion stability when a flame is generated can be improved.

  Further, since the plate-like member 56 is arranged so that the obstructing surface 56a is substantially perpendicular to the flow of exhaust gas, the flow of exhaust gas can be effectively prevented. The plate-like member is not limited to this arrangement, and for example, it may be arranged such that the obstructing surface is inclined with respect to the flow of exhaust gas.

  FIG. 14 is a schematic cross-sectional view of a portion of the exhaust pipe of the second exhaust purification device in the present embodiment. In the second exhaust purification device, a plate-like member 58 as an obstruction member is arranged on the upstream side of the glow plug 51 and the fuel supply valve 15. The plate-like member 58 has an outer dimension that reduces the flow velocity of the exhaust gas that collides with the heat generating portion 51a. Thus, the inhibition member may be disposed on the upstream side of the fuel supply valve.

  The inhibition member in the present embodiment is formed in a flat plate shape, but is not limited to this form, and may be formed to be curved, for example. In addition, the plate-like member in the present embodiment has a square planar shape, but is not limited to this form, and a plate-like member having an arbitrary shape can be employed. Alternatively, the inhibition member is not limited to a plate shape, and may be formed in a lump shape. The blocking member may be formed so as to reduce the flow rate of the exhaust gas that collides with the heat generating portion of the ignition means.

  Moreover, although the plate-shaped member in this Embodiment is supported by the exhaust pipe through the support member, it is not restricted to this form, A plate-shaped member can be supported by arbitrary structures. For example, the plate-like member may extend toward the wall of the exhaust pipe and be directly fixed to the exhaust pipe.

  FIG. 15 is a schematic cross-sectional view of a third exhaust purification device in the present embodiment. FIG. 15 is a schematic cross-sectional view of an exhaust pipe portion of the third exhaust purification device. In the third exhaust purification apparatus, the exhaust pipe 12 constituting the engine exhaust passage has a deformed portion in which a wall portion is deformed. The deformation part is formed so as to protrude in the radial direction of the exhaust pipe 12. In the third exhaust purification apparatus, the wall portion of the exhaust pipe 12 has a recess 12a as a deforming portion. The recess 12a is formed by the wall portion of the exhaust pipe 12 projecting outward.

  The recess 12a is formed on the opposite side of the circumferential direction of the exhaust pipe 12 from the direction in which the glow plug 51 is disposed. As for the glow plug 51, the whole heat generating part 51a is arrange | positioned inside the recessed part 12a. The glow plug 51 is disposed downstream of the fuel supply valve 15. The glow plug 51 is inserted into the exhaust pipe 12 from the side opposite to the direction in which the fuel supply valve 15 is disposed in the circumferential direction of the exhaust pipe 12. For this reason, the fuel can be injected from the fuel supply valve 15 toward the heat generating portion 51 a of the glow plug 51.

  In the third exhaust purification device, the heat generating portion 51a is formed so as to be hidden inside the recess 12a when the exhaust pipe 12 is viewed from the upstream side. The recess 12a has an outer dimension that hides the entire heat generating portion 51a. By disposing the heat generating portion 51a inside the recess 12a, the collision speed when the exhaust gas collides with the heat generating portion 51a can be reduced. As a result, ignition performance and combustion stability can be improved.

  FIG. 16 is a schematic cross-sectional view of a fourth exhaust purification device in the present embodiment. FIG. 16 is a schematic cross-sectional view of the exhaust pipe portion of the fourth exhaust purification device. In the fourth exhaust purification device, the exhaust pipe 12 is formed with a convex portion 12b as a deforming portion. The convex part 12b is formed by the wall part of the exhaust pipe 12 projecting inward. The convex portion 12 b is disposed on the upstream side of the glow plug 51 at a distance from the glow plug 51. The glow plug 51 is disposed downstream of the fuel supply valve 15. The glow plug 51 is disposed on the opposite side of the circumferential direction of the exhaust pipe 12 with respect to the direction in which the fuel supply valve 15 is disposed.

  The convex portion 12b has an outer dimension that hides the entire heat generating portion 51a of the glow plug 51 when viewed from the upstream side. The convex portion 12b is close to the glow plug 51 so as to prevent the exhaust gas flow indicated by the arrow 90 and to reduce the collision speed of the exhaust gas colliding with the heat generating portion 51a. Moreover, the convex part 12b is arrange | positioned away from the heat-emitting part 51a so that oxygen contained in exhaust gas can be taken in when a fuel burns.

  In the fourth exhaust emission control device, the wall portion of the exhaust pipe 12 has the convex portion 12b as the deformation portion, so that the collision speed of the exhaust gas that collides with the heat generating portion 51a of the glow plug 51 can be reduced. As a result, ignition performance and combustion stability can be improved.

  The deformed portion of the exhaust pipe in the present embodiment is formed on the side opposite to the direction in which the fuel supply valve is arranged in the circumferential direction of the exhaust pipe, but is not limited to this form, for example, the circumferential direction of the exhaust pipe Among them, the glow plug may be arranged in the same direction as the direction in which the fuel supply valve is arranged, and a deformed portion may be further formed.

  Other configurations and the like are the same as those in the first embodiment, and thus description thereof will not be repeated here.

(Embodiment 3)
With reference to FIGS. 17 and 18, the exhaust gas purification apparatus for an internal combustion engine in the third embodiment will be described.

  FIG. 17 is a schematic cross-sectional view of the portion of the exhaust pipe of the exhaust gas purification apparatus in the present embodiment. FIG. 18 is a schematic perspective view of the fuel supply valve, the glow plug, and the plate member in the present embodiment. The exhaust emission control device in the present embodiment includes a plate-like member 57. The plate-like member 57 has an L-shaped cross section. The plate-like member 57 has a flat plate portion 57a and a flat plate portion 57b. The plate member 57 is formed such that the flat plate portion 57a and the flat plate portion 57b are substantially vertical.

  The fuel supply valve 15 and the glow plug 51 are disposed in a region surrounded by the plate-like member 57 and the exhaust pipe 12. The flat plate portion 57a is disposed upstream of the position where the glow plug 51 is disposed. The flat plate portion 57a has an obstruction surface that inhibits the flow of exhaust gas. The flat plate portion 57 a is disposed so that the obstructing surface is substantially perpendicular to the flow direction of the exhaust gas indicated by the arrow 90. The flat plate portion 57a is fixed to the exhaust pipe 12. The flat plate portion 57 b has a reflection surface that reflects the fuel, and is arranged so that the reflection surface is substantially parallel to the flow direction of the exhaust gas indicated by the arrow 90.

  In the exhaust emission control device of the present embodiment, the flat plate portions 57a and 57b of the plate-like member 57 can reflect the fuel passing through the side of the heat generating portion 51a and direct it to the heat generating portion 51a. The fuel can be reflected once by the flat plate portion 57 b of the plate-like member 57 and directed to the heat generating portion 51 a of the glow plug 51. Further, as shown by an arrow 95, the fuel can be reflected by the flat plate portion 57b after being reflected by the flat plate portion 57a, and the fuel can be collected in the heat generating portion 51a. That is, the flat plate portion 57a has a function of reflecting fuel in addition to the function of inhibiting the flow of exhaust gas. Thus, the plate-like member 57 functions as a fuel reflector that reflects part of the fuel and directs it toward the heat generating portion. As a result, the ignition performance of the fuel can be improved, and further the combustion stability can be improved.

  The flat plate portion 57a has an outer dimension that hides the entire heat generating portion 51a of the glow plug 51 when the exhaust pipe 12 is viewed from the upstream side. The plate-like member 57 functions as an inhibiting member that inhibits the flow of exhaust gas. The plate-like member 57 can reduce the collision speed of the exhaust gas that collides with the heat generating portion 51a. As a result, the ignition performance of the fuel can be improved, and further the combustion stability can be improved.

  Other configurations, operations, and effects are similar to those of the first embodiment or the second embodiment, and thus description thereof will not be repeated here.

  Each of the above embodiments can be combined. In the respective drawings described above, the same or corresponding parts are denoted by the same reference numerals. In addition, said embodiment is an illustration and does not limit invention. In the embodiments, changes within the scope of the claims are intended.

12 an exhaust pipe 12a recess 12b projections 13 oxidation catalyst 15 fuel supply valve 16 particulate filter 17 NO _X storing catalyst 26 the temperature sensor 27 temperature sensor 28 differential pressure sensor 30 the electronic control unit 51 glow plug 51a heating unit 52 to 58 plate-like member 52a Reflecting surface 53a Reflecting surface 54a Reflecting surface 55a Flat plate portion 55b Bending portion 56a Inhibiting surface 57a, 57b Flat plate portion 59 Support member

Claims (6)

An exhaust pipe having a wall and forming at least a part of an engine exhaust passage;
An exhaust treatment device disposed in the engine exhaust passage for purifying exhaust gas;
A fuel supply means disposed upstream of the exhaust treatment device in the engine exhaust passage, and for injecting fuel into the engine exhaust passage;
A heating unit disposed inside the engine exhaust passage, and ignition means for igniting the fuel injected from the fuel supply unit;
The wall portion has a deforming portion that protrudes toward either the inside or the outside of the exhaust pipe,
The exhaust gas purification apparatus for an internal combustion engine, wherein the deforming portion has an outer dimension that hides the entire heat generating portion when the engine exhaust passage is viewed from the upstream side. The deforming portion is disposed on the upstream side of the igniting means at a distance from the igniting means, and includes a convex portion projecting inside the exhaust pipe,
The exhaust purification device for an internal combustion engine according to claim 1, wherein the convex portion blocks a part of the engine exhaust passage. The deformable portion includes a concave portion that protrudes outside the exhaust pipe,
2. The exhaust gas purification apparatus for an internal combustion engine according to claim 1, wherein in the ignition means, the heat generating portion is disposed inside the concave portion. An exhaust treatment device disposed in the engine exhaust passage for purifying exhaust gas;
Ignition means having a heat generating portion disposed on the upstream side of the exhaust treatment device in the engine exhaust passage and increasing in temperature;
A fuel supply means that is disposed upstream of the ignition means and injects fuel toward the heat generating portion;
The fuel supply means and the ignition means reflect the fuel passing through the side of the heat generating part without directly colliding with the heat generating part and being reflected by the wall part of the engine exhaust passage toward the heat generating part. An exhaust emission control device for an internal combustion engine, characterized by being arranged. An exhaust treatment device disposed in the engine exhaust passage for purifying exhaust gas;
A fuel supply means disposed upstream of the exhaust treatment device in the engine exhaust passage, and for injecting fuel into the engine exhaust passage;
A heating unit disposed inside the engine exhaust passage, and ignition means for igniting the fuel injected from the fuel supply unit;
An obstruction member that blocks a part of the engine exhaust passage and reduces the flow rate of the exhaust gas that collides with the heat generating portion is disposed upstream of the ignition means and spaced from the ignition means. An exhaust purification device for an internal combustion engine.   6. The exhaust emission control device for an internal combustion engine according to claim 5, wherein the inhibiting member has an outer dimension that hides the entire heat generating portion when the engine exhaust passage is viewed from the upstream side.

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