JP2018145837A - Exhaust emission control device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an exhaust emission control device capable of suppressing heat damage due to exhaust gas during regenerating a filter using a burner.SOLUTION: The exhaust emission control device includes the filter for trapping particulate matters included in exhaust gas flowing in an exhaust passage, and the burner for supplying combustion gas obtained by combusting fuel through the exhaust passage to the filter to regenerate the filter. The exhaust emission control device further includes a secondary air pressure feeder 50 to be driven when regenerating the filter, and a discharge passage 58 having a discharge port 60 for discharging cooling air pressure-fed by the secondary air pressure feeder 50, the discharge passage 58 being arranged in parallel to an exhaust pipe 14 having a first exhaust port 15 with its discharge direction set toward the exhaust gas exhausted from the first exhaust port 15.SELECTED DRAWING: Figure 2

Description

  The present invention relates to an exhaust purification device that regenerates a filter using a burner.

  2. Description of the Related Art Conventionally, a method using a burner is known as one of methods for regenerating a filter that captures particulate matter (PM) contained in exhaust gas in an exhaust gas purification device that purifies the exhaust gas of the engine. ing. For example, Patent Document 1 discloses that regeneration of a filter by supplying combustion gas generated by a burner to the filter is performed when the vehicle is stopped.

JP 2012-117454 A

  By the way, the exhaust gas discharged from the exhaust port of the exhaust passage at the time of regeneration of the filter using the burner has a higher temperature than that at the time of non-regeneration of the filter due to the combustion of the combustion gas and PM described above. Therefore, in vehicles that regenerate the filter using a burner when the vehicle is stopped, the exhaust gas discharged from the discharge port tends to stay near the discharge port. Measures against heat damage caused by exhaust gas are required.

  An object of the present invention is to provide an exhaust emission control device capable of suppressing heat damage caused by exhaust gas during regeneration of a filter using a burner.

  An exhaust emission control device that solves the above-described problems is a filter that is disposed in an exhaust passage and captures particulate matter contained in exhaust gas, and regenerates the filter by supplying combustion gas obtained by burning fuel to the filter. And a discharge passage having a discharge port for discharging the cooling air pumped by the pneumatic feeder, in parallel with the end portion of the exhaust passage. And the discharge passage having a discharge direction set toward the exhaust gas discharged from the discharge port of the exhaust passage.

  According to the above configuration, when the filter is regenerated, cooling air is supplied from the discharge port of the discharge passage toward the exhaust gas discharged from the discharge port. Thereby, the temperature of the exhaust gas can be lowered by mixing the exhaust gas and the cooling air. As a result, heat damage caused by exhaust gas can be suppressed.

In the exhaust emission control device having the above configuration, the discharge passage may have the discharge direction set toward the center of the discharge port in a plan view from a direction facing the discharge port.
According to the above configuration, the discharge passage can discharge the cooling air toward the center of the discharge port in a plan view from the direction facing the discharge port. Thereby, the mixing degree of exhaust gas and cooling air can be raised.

In the exhaust emission control device having the above-described configuration, it is preferable that the discharge passage has a linear shape with a constant flow path cross-sectional area.
According to the above configuration, since the cooling air discharged from the discharge port is difficult to diffuse, the direction of the cooling air can be more reliably performed.

The exhaust emission control device having the above configuration preferably includes a plurality of the discharge passages, and the discharge ports are arranged at equal intervals in the circumferential direction of the discharge port.
According to the above configuration, since the degree of mixing of the exhaust gas and the cooling air is made uniform, the temperature of the exhaust gas can be effectively reduced.

  The exhaust emission control device having the above-described configuration further includes a cylindrical outside air guide member that surrounds the first outlet that is the outlet and the discharge passage, and the outside air guide member is located at a position facing the first outlet. Forming a second discharge port and forming an outside air guide passage that is located outside the discharge passage and guides the outside air that is attracted by the exhaust gas flowing from the first discharge port toward the second discharge port. Is preferred.

  According to the above configuration, the outside air attracted by the exhaust gas flowing between the first exhaust port and the second exhaust port can be effectively supplied to the exhaust gas.

The figure which shows schematic structure of one Embodiment of an exhaust gas purification apparatus. Sectional drawing which shows the cross-section in the 1st discharge port vicinity. The top view which shows the planar view structure of the exhaust pipe and discharge head from the direction which opposes a 1st discharge port. The top view which shows the planar view structure of the exhaust pipe from the direction which opposes a 1st discharge port, and an external air guide member. The graph which shows an example of the comparison result of exhaust gas temperature.

An embodiment of an exhaust emission control device will be described with reference to FIGS.
As shown in FIG. 1, the exhaust purification device 20 includes a filter 23 that captures particulate matter (PM) contained in exhaust gas discharged from the engine 10. The filter 23 is accommodated in an accommodating portion 12 provided in the middle of the exhaust passage 11 of the engine 10. The accommodating portion 12 is a cylindrical portion having a larger diameter than other portions in the exhaust passage 11. The filter 23 is, for example, a wall flow filter made of ceramic or stainless steel having excellent heat resistance, and when the temperature is raised to a regeneration temperature Tfr (for example, 600 ° C.), PM is incinerated to regenerate the filter function.

  The exhaust emission control device 20 includes a mixer 21 and a pre-stage oxidation catalyst 22 on the upstream side of the filter 23 in the accommodating portion 12. Further, the exhaust purification device 20 includes a rear-stage oxidation catalyst 24 on the downstream side of the filter 23 in the housing portion 12. The mixer 21 stirs the exhaust gas and increases the uniformity of the exhaust gas flowing into the filter 23. In addition, the mixer 21 stirs the combustion gas generated by the burner 30 described later and increases the uniformity of the combustion gas flowing into the filter 23, thereby suppressing local overheating of the filter 23 during regeneration of the filter 23. . The pre-stage oxidation catalyst 22 is located between the mixer 21 and the filter 23, and converts hydrocarbons and carbon monoxide contained in the exhaust gas into water and carbon dioxide. The post-stage oxidation catalyst 24 converts the hydrocarbons and carbon monoxide contained in the exhaust gas that has passed through the filter 23 into water and carbon dioxide.

  The exhaust purification device 20 includes a burner 30 that is driven when the filter 23 is regenerated. The burner 30 includes a combustion unit 31 in which fuel is combusted, a fuel supply unit 32 that supplies fuel to the combustion unit 31, and an air supply unit 36 that supplies combustion air to the combustion unit 31.

  The fuel supply unit 32 supplies fuel to the combustion unit 31 through the fuel supply path 35 by pumping the fuel stored in the fuel tank 33 with an electric pump 34. The air supply unit 36 supplies combustion air to the combustion unit 31 through the combustion air supply path 38 by pumping outside air with an electric first pneumatic feeder 37.

  In the combustion unit 31, an air-fuel mixture of the fuel supplied from the fuel supply unit 32 and the combustion air supplied from the air supply unit 36 is generated, and the generated air-fuel mixture is ignited by the glow plug 39 to cause combustion. Be started. Combustion in the combustion unit 31 continues until the fuel supply by the fuel supply unit 32 is cut off, and the combustion gas generated by the combustion flows into the most upstream part of the storage unit 12. The combustion gas flowing into the storage unit 12 is stirred by the mixer 21 and then flows into the filter 23 through the pre-stage oxidation catalyst 22 to raise the temperature of the filter 23. Thereafter, the combustion gas passes through the post-stage oxidation catalyst 24 and then is connected to the downstream end of the accommodating portion 12 and to the reduced diameter portion 13 to constitute the end portion of the exhaust passage 11. The gas is discharged from the first discharge port 15 through the exhaust pipe 14.

  The gas discharged from the first discharge port 15 is referred to as exhaust gas. This exhaust gas is an exhaust gas discharged by the engine 10 when only the engine 10 is driven, and a combustion gas generated by the burner 30 when only the burner 30 is driven. The exhaust gas is a mixed gas of exhaust gas and combustion gas when the engine 10 and the burner 30 are driven.

The exhaust emission control device 20 includes a cooling unit 40 that cools the storage unit 12 and the exhaust gas discharged from the first exhaust port 15 when the filter 23 is regenerated.
The cooling part 40 has a first outer cylinder part 41 that constitutes a double-pipe structure with the accommodating part 12 as an inner cylinder part. The first outer cylinder portion 41 forms a first cooling passage 42 that surrounds the front-stage oxidation catalyst 22, the filter 23, and the rear-stage oxidation catalyst 24 on the outer peripheral portion of the housing portion 12. The cooling unit 40 also has a first connection passage 43 that connects the combustion air supply passage 38 and the first cooling passage 42. The first connection passage 43 is connected to a portion surrounding the first-stage oxidation catalyst 22 located on the upstream side of the filter 23 with respect to the first cooling passage 42. In the cooling unit 40, a part of the outside air pumped by the first pneumatic feeder 37 is supplied to the first cooling passage 42 through the first connection passage 43 as cooling air.

  As shown in FIG. 2, the cooling part 40 has a second outer cylinder part 45 that constitutes a double pipe structure in which the reduced diameter part 13 of the exhaust passage 11 is an inner cylinder part. The second outer cylinder portion 45 forms a second cooling passage 46 communicating with the first cooling passage 42 in the outer peripheral portion of the reduced diameter portion 13. The second outer cylinder part 45 is connected to the end of the first outer cylinder part 41 and has a larger diameter reduction ratio than the diameter reduction part 13 so that the flow passage cross-sectional area of the second cooling passage 46 gradually decreases. It has a cylindrical shape with a reduced diameter. In addition, the cooling unit 40 includes a third outer cylinder part 47 constituting a double pipe structure in which the exhaust pipe 14 of the exhaust passage 11 is an inner cylinder part. The third outer cylinder portion 47 forms a third cooling passage 48 communicating with the second cooling passage 46 on the outer peripheral portion of the exhaust pipe 14. The third outer cylinder portion 47 is connected to the end portion of the second outer cylinder portion 45 and has a cylindrical shape that keeps the flow passage cross-sectional area of the third cooling passage 48 constant.

  The cooling unit 40 connects the electric second pneumatic transmitter 50, the discharge side of the second pneumatic transmitter 50, and the second cooling passage 46, and uses the outside air pumped by the second pneumatic transmitter 50 as cooling air. And a second connection passage 51 that supplies the second cooling passage 46. In the cooling unit 40, the cooling air supplied to the second cooling passage 46 through the second connection passage 51 and the cooling air that has cooled the storage unit 12 in the first cooling passage 42 are merged, and the merged cooling air is the first 3 flows into the cooling passage 48.

  As shown in FIGS. 2 and 3, the cooling unit 40 includes a discharge head 55 that discharges the cooling air that has flowed into the third cooling passage 48. The discharge head 55 has a cylindrical shape having a thick peripheral wall surrounding the end portion of the exhaust pipe 14 on the first discharge port 15 side, and has an inner peripheral edge joined to the exhaust pipe 14 and a third outer periphery. And an outer peripheral edge portion joined to the cylindrical portion 47. The discharge head 55 has a smaller outer diameter at the downstream side in the exhaust gas flow direction so that the shape of the outer peripheral surface follows the shape of the outside air guide member 64 described later. The discharge head 55 has a plurality of discharge passages 58 (four in this embodiment) arranged in parallel with the exhaust pipe 14. 2 and 3, thick arrows indicate the flow of exhaust gas, and thin arrows indicate the flow of outside air.

  Each discharge passage 58 has an introduction port 59 for introducing the cooling air flowing through the third cooling passage 48 and a discharge port that opens to the annular discharge surface 60a overhanging the first discharge port 15 and discharges the cooling air. 60. Each discharge passage 58 is positioned closer to the exhaust pipe 14 and closer to the first discharge port 15 so that the cooling air is discharged toward the discharge gas discharged from the first discharge port 15. The discharge direction is set toward the center of the first discharge port 15 in a plan view from the facing direction. Each discharge passage 58 is formed in the same cross-sectional shape having a constant flow passage cross-sectional area so that the accuracy in the discharge direction is increased, and has a flow passage length sufficiently large with respect to the flow passage width. It is formed in a linear shape. The discharge ports 60 of the discharge passages 58 are arranged at equal intervals in the circumferential direction centering on the first discharge port 15 in a plan view from the direction facing the first discharge port 15. It should be noted that the amount of outside air pumped by the second pneumatic feeder 50 is preferably equal to or greater than the amount of outside air discharged by the first pneumatic feeder 37. According to such a configuration, the flow rate of the cooling air discharged from the discharge port 60 can be further increased.

  As shown in FIGS. 2 and 4, the cooling unit 40 includes a cylindrical outside air guide member 64 that surrounds the third outer cylinder portion 47 and the discharge head 55. The outside air guide member 64 forms a second discharge port 65 at a position facing the first discharge port 15, and the second discharge port 65 extends from a portion facing the discharge head 55 in the radial direction of the exhaust pipe 14. The portion closer to the outlet 65 has a shape with a reduced diameter. The outside air guide member 64 has an annular shape in the radial direction of the exhaust pipe 14 on the outer peripheral portion of the third outer cylinder portion 47 and the discharge head 55, and the portion closer to the second discharge port 65 is closer to the first discharge port 15. An outside air guide passage 66 located on the center side is formed. The outside air guide passage 66 has an induction port 67 formed by the third outer cylinder portion 47 and the outside air guide member 64, and a supply port 68 formed by the discharge head 55 and the outside air guide member 64, It guides the outside air attracted by the venturi effect due to the exhaust gas flowing from the first exhaust port 15 toward the second exhaust port 65.

  The outside air guide member 64 is connected to the outer peripheral surface of the third outer cylinder portion 47 by a plurality of connecting pieces 69. Each connecting piece 69 is located at a position facing the discharge port 60 in the radial direction of the exhaust pipe 14 in a plan view from the direction facing the first discharge port 15. Further, the outside air guide member 64 has an opening edge of the second discharge port 65 outside the opening edge of the first discharge port 15 in a plan view from the direction facing the first discharge port 15.

  The opening area of the supply port 68 of the outside air guide passage 66 is set to be larger than the total opening area of the discharge ports 60 in the discharge head 55. Thereby, the outside air can be easily guided to the exhaust gas through the outside air guide passage 66, and the flow velocity of the cooling air discharged from the discharge port 60 can be increased. The opening area of the supply port 68 is a flow path cross-sectional area based on the shortest distance between the outer peripheral tip of the ejection head 55 and the outside air guide member 64, as indicated by a two-dot chain line in FIG.

  As shown in FIG. 1, when the filter 23 is regenerated, the above-described pump 34, first pneumatic feeder 37, glow plug 39, and second pneumatic feeder 50 are supplied with electric power through a BCU (Battery Control Unit) 70. Is driven. The BCU 70 supplies power from the battery 71 or power from the external AC power supply 73 supplied through the AC-DC converter 72. The BCU 70 gives priority to power supply by the external AC power source 73 over the battery 71. The BCU 70 is based on a control signal from an ECU (Electronic Control Unit) 75 that is a control unit that performs overall control of the exhaust emission control device 20, and the pump 34, the first pneumatic transmitter 37, the glow plug 39, and the second pneumatic transmitter. 50 to control the power supply. For example, when a condition for regenerating the filter 23 is satisfied while the engine 10 is stopped, the ECU 75 outputs a control signal for regenerating the filter 23 to the BCU 70 while the engine 10 is stopped. In addition to the engine 10 being stopped, for example, the condition is that the accumulated amount of PM when the engine 10 is stopped exceeds a predetermined threshold value, or the regeneration of the filter 23 is instructed by the operation of the operation switch by the driver. The signal to be input is input to the ECU 75.

  In the regeneration of the filter 23, the ECU 75 controls the pump 34, the first pneumatic feeder 37, and the glow plug 39 so as to continue supplying the combustion gas to the housing portion 12 and to control the second pneumatic feeder 50. Thus, the cooling air is continuously sent to the second cooling passage 46. Then, when the PM accumulation amount in the filter 23 decreases to a predetermined value, the ECU 75 stops the pump 34 and stops the generation of combustion gas, and then stops the pneumatic transmitters 37 and 50 after a predetermined time has elapsed. . The ECU 75 is configured to forcibly end the regeneration of the filter 23 when the exhaust gas temperature, which is a detection value of the temperature sensor 76 that detects the temperature of the exhaust gas in the vicinity of the second exhaust port 65, is excessively high. It may be.

The operation of the above-described exhaust purification device 20 will be described.
In the exhaust emission control device 20, when the filter 23 is regenerated, the combustion gas accompanying the drive of the burner 30 flows into the storage unit 12, so that the temperature of the filter 23 rises and PM is eventually incinerated.

  On the other hand, when the filter 23 is regenerated, the storage unit 12 is heated not only with the inflow of combustion gas but also with combustion of PM in the filter 23. Such a temperature rise of the housing portion 12 can be suppressed by the traveling wind flowing around the housing portion 12 if the filter 23 is regenerated while the vehicle is traveling. However, when the filter 23 is regenerated while the engine 10 is stopped, the running wind does not flow around the housing portion 12, and thus the housing portion 12 may be overheated. In this regard, in the exhaust purification device 20 described above, a part of the outside air pressure-fed by the first pneumatic feeder 37 is supplied as cooling air to the first cooling passage 42 provided in the outer peripheral portion of the housing portion 12. The accommodating part 12 is cooled. Therefore, even if the filter 23 is regenerated while the engine 10 is stopped, overheating of the housing portion 12 can be suppressed.

  Further, when the filter 23 is regenerated, the combustion gas generated by the burner 30 is discharged after being heated by PM combustion. Such exhaust gas is effectively diffused to the rear of the vehicle by traveling wind or the like if the filter 23 is regenerated while the vehicle is traveling. However, when the filter 23 is regenerated while the engine 10 is stopped, the exhaust gas is not diffused to the rear of the vehicle by the traveling wind, but is also discharged from the first outlet 15 because the engine 10 is stopped. The flow velocity of the gas also becomes small and tends to stay near the first discharge port 15. In this regard, in the exhaust emission control device 20, the cooling air that has cooled the housing portion 12 by the first cooling passage 42 and the cooling air that has been pumped by the second pneumatic feeder 50 to the second cooling passage 46 are discharged from the discharge head 55. The gas is discharged from the outlet 60 toward the exhaust gas. Further, in the exhaust purification device 20, the outside air attracted by the venturi effect due to the exhaust gas flowing from the first exhaust port 15 toward the second exhaust port 65 is supplied to the exhaust gas through the external air guide passage 66. As a result, the temperature of the exhaust gas discharged from the second exhaust port 65 is lowered, and the exhaust gas is easily diffused by increasing the flow velocity when discharged from the second exhaust port 65.

  FIG. 5 is a graph showing an example of a comparison result of the exhaust gas temperature that is a detection value of the temperature sensor 76. In FIG. 5, the embodiment is the exhaust purification device 20 described above, and the comparative example is an exhaust purification device having a configuration in which the cooling unit 40 is omitted from the exhaust purification device 20. As shown in FIG. 5, even if the exhaust gas temperature was about 550 ° C. in the comparative example, it was confirmed that it could be cooled to about 90 ° C. (about 1/6) in the example.

According to the exhaust emission control device 20 of the above embodiment, the effects listed below can be obtained.
(1) The temperature of the exhaust gas discharged from the second exhaust port 65 can be lowered by discharging the cooling air from the discharge port 60 to the exhaust gas discharged from the first exhaust port 15. As a result, heat damage caused by exhaust gas can be suppressed.

  (2) The discharge passage 58 has a discharge direction set toward the center of the first discharge port 15 in a plan view from the direction facing the first discharge port 15. As a result, the cooling air discharged from the discharge port 60 can easily reach the central portion of the exhaust gas discharged from the first discharge port 15, so that the degree of mixing of the exhaust gas and the cooling air is increased and discharged. The temperature distribution in the gas can be made uniform.

  (3) The discharge passage 58 has a linear shape with a constant cross-sectional area. Thereby, since the cooling air discharged from the discharge port 60 becomes difficult to diffuse, the direction of the cooling air can be more reliably performed. As a result, the flow rate of the cooling air when mixed with the exhaust gas is increased, and the degree of mixing of the exhaust gas and the cooling air can be further increased.

  (4) The discharge ports 60 of the discharge passages 58 are arranged at equal intervals in the circumferential direction centering on the first discharge port 15 in a plan view from the direction facing the first discharge port 15 of the exhaust pipe 14. Yes. Therefore, the temperature of the exhaust gas can be effectively reduced, and the temperature distribution in the exhaust gas can be further uniformed.

  (5) The outside air guide member 64 forms the second discharge port 65 at a position facing the first discharge port 15, and also due to the venturi effect due to the exhaust gas flowing from the first discharge port 15 toward the second discharge port 65. An outside air guide passage 66 for guiding the outside air to be attracted is formed. According to such a configuration, since the outside air is attracted by the exhaust gas before being diffused into the atmosphere, it is possible to effectively supply the outside air to the exhaust gas by the venturi effect.

  (6) The outside air guide member 64 has an opening edge of the second discharge port 65 outside the opening edge of the first discharge port 15 in a plan view from the direction facing the first discharge port 15. According to such a configuration, the exhaust gas that has passed through the first discharge port 15 can be discharged smoothly from the second discharge port 65. Thereby, the raise of the static pressure in the exhaust gas which flows between the 1st discharge port 15 and the 2nd discharge port 65 can be suppressed. As a result, the outside air can be effectively attracted by the venturi effect.

  (7) The outside air guide member 64 has a shape that decreases in diameter from the portion facing the discharge head 55 in the radial direction of the exhaust pipe 14 to the second discharge port 65 toward the second discharge port 65. Therefore, the outside air guide passage 66 is located closer to the center direction side of the first discharge port 15 toward the second discharge port 65. According to such a configuration, since the inflow of exhaust gas to the outside air guide passage 66 through the supply port 68 is suppressed with a high probability, the outside air can be more effectively attracted by the venturi effect.

  (8) In the exhaust purification device 20, a part of the outside air pressure-fed by the first pneumatic feeder 37 is supplied as cooling air to the first cooling passage 42 provided in the outer peripheral part of the accommodating part 12, so that the accommodating part. 12 is cooled. Therefore, even if the filter 23 is regenerated while the engine 10 is stopped, overheating of the housing portion 12 can be suppressed.

(9) Since the second cooling passage 46 is formed in the outer peripheral portion of the reduced diameter portion 13 and the third cooling passage 48 is formed in the outer peripheral portion of the exhaust pipe 14, overheating of the reduced diameter portion 13 and the exhaust pipe 14 is suppressed. .
(10) In addition to the cooling air pumped by the second pneumatic feeder 50, the cooling air supplied to the first cooling passage 42 is discharged from the discharge passage 58 through the second and third cooling passages 46 and 48. The flow rate of the cooling air discharged from the outlet 60 is increased. Thereby, the cooling air supplied to the 1st cooling channel | path 42 can be utilized effectively for the temperature fall of exhaust gas.

  (11) The opening area of the supply port 68 of the outside air guide passage 66 is set to be larger than the total opening area of the discharge ports 60 in the discharge head 55. Thereby, mixing of exhaust gas and cooling air can be performed effectively by increasing the flow velocity of the cooling air discharged from the discharge port 60. In addition, the outside air can be effectively attracted through the outside air guide passage 66.

  (12) In the exhaust gas purification device 20, when the regeneration of the filter 23 is completed, the pneumatic feeders 37 and 50 are stopped after the fuel supply is shut off. Accordingly, it is possible to more reliably suppress the exhaust gas having a high temperature from being discharged from the second exhaust port 65 while scavenging the combustion gas in the exhaust passage 11.

  (13) The second connection passage 51 discharges the cooling air toward the peripheral wall of the reduced diameter portion 13 constituting the exhaust passage 11, that is, toward the portion inclined toward the traveling direction side of the cooling air, Cooling air is supplied to the second cooling passage 46. According to such a configuration, the cooling air supplied to the second cooling passage 46 can be easily guided to the third cooling passage 48 side, and energy loss due to the collision with the peripheral wall can be reduced. As a result, a decrease in the flow rate of the cooling air discharged from the discharge port 60 can be suppressed.

  (14) The outside air guide member 64 forms an induction port 67 between the third outer cylinder portion 47 and the outside air guide member 64. According to such a configuration, it is possible to attract more outside air to the outside air guide passage 66 by increasing the opening area of the attraction port as compared with the case where the attraction port is formed between the reduced diameter portion 13. .

In addition, the said embodiment can also be suitably changed and implemented as follows.
In the exhaust purification device 20, the cooling air supplied to the first cooling passage 42 is not the outside air pressure-fed by the first pneumatic feeder 37 but part of the outside air pressure-fed by the second pneumatic feeder 50. Good. Moreover, the air pressure to the combustion part 31, the 1st cooling channel | path 42, and the 2nd cooling channel | path 46 may be performed with one pneumatic feeder, and may be performed with three or more pneumatic feeders.

  -Exhaust purification device 20 should just have composition which cools exhaust gas exhausted from the 1st exhaust port 15 with cooling air discharged from discharge passage 58, and cools storage part 12 which stores filter 23 It is not necessary to have the structure to do.

The outside air guide member 64 only needs to have a cylindrical shape that forms the outside air guide passage 66 that guides outside air attracted by the exhaust gas, and the portion closer to the second discharge port 65 may not be reduced in diameter.
The outside air guide passage 66 may be a passage extending along the radial direction of the first discharge port 15, or may be a passage having a smaller channel cross-sectional area as it is closer to the second discharge port 65.

  The outside air guide member 64 may have an opening edge of the second discharge port 65 inside the opening edge of the first discharge port 15 in a plan view from the direction facing the first discharge port 15. Further, in the same plan view, the opening edge of the second discharge port 65 intersects with the opening edge of the first discharge port 15 because the second discharge port 65 is displaced from the first discharge port 15. It may be a configuration.

The exhaust purification device 20 may have a configuration in which the outside air guide member 64 is omitted.
The exhaust purification device 20 only needs to have one or more discharge passages 58. Further, when the exhaust purification device 20 includes a plurality of discharge passages 58, the discharge ports 60 are arranged at equal intervals in the circumferential direction of the first discharge port 15 in a plan view from the direction facing the first discharge port 15. It does not have to be. For example, the discharge port 60 may be arranged so that the cooling air blown from above to the exhaust gas increases.

  The discharge passage 58 is not limited to the structure formed in the discharge head 55, and may be formed by, for example, a tubular member, or by a double tube structure like each cooling passage 42, 46, 48. The structure formed may be sufficient.

  The discharge passage 58 only needs to have a discharge direction set toward the exhaust gas discharged from the first discharge port 15. Therefore, the discharge passage 58 is not limited to a linear shape having a constant flow path cross-sectional area, and may be configured to have a shape in which the flow path cross-sectional area becomes smaller toward a portion closer to the discharge port 60. Further, the discharge direction of the discharge passage 58 may be set at a position shifted from the center of the first discharge port 15 in a plan view from the direction facing the first discharge port 15.

The filter 23 may be a catalyzed filter having a catalyst layer on the surface layer.
The exhaust air purification device 20 is configured so that the higher the detected value of the temperature sensor 76 and the more fuel supplied by the fuel supply unit 32, the more cooling air is discharged from the discharge port 60. The power supply to 50 may be controlled. According to such a configuration, the temperature of the exhaust gas can be more reliably lowered.

  The exhaust purification device 20 can be applied to a vehicle having a filter 23 that captures PM contained in exhaust gas. The engine 10 is, for example, a diesel engine, a gasoline engine, or a gas engine. May be.

The exhaust emission control device 20 may be controlled so that the temperature of the exhaust gas is lowered not only when the engine 10 is stopped but also when the filter 23 is regenerated when the engine 10 is driven.
The exhaust purification device 20 may not include the pre-stage oxidation catalyst 22 between the mixer 21 and the filter 23 when it is not necessary to oxidize hydrocarbons or carbon monoxide contained in the exhaust gas. Further, the exhaust purification device 20 may not include the post-stage oxidation catalyst 24 when it is not necessary to oxidize hydrocarbons or carbon monoxide contained in the exhaust gas that has passed through the filter 23.

Next, a technical idea grasped from the above-described embodiment will be added.
(Appendix A)
The exhaust emission control device according to claim 5, wherein the second exhaust port is located outside the first exhaust port in a plan view from a direction facing the first exhaust port.

  According to the said structure, the exhaust gas which passed the 1st discharge port can be discharged | emitted smoothly from a 2nd discharge port. Thereby, the raise of the static pressure in the exhaust gas which flows between a 1st discharge port and a 2nd discharge port can be suppressed. As a result, the outside air can be effectively attracted by the exhaust gas.

(Appendix B)
The exhaust emission control device according to claim 5, wherein the outside air guide member is reduced in diameter toward a portion closer to the second discharge port.
According to the above configuration, since the inflow of the exhaust gas to the outside air guide passage is suppressed with a high probability, the outside air can be more effectively attracted by the exhaust gas.

(Appendix C)
A cooling passage formed in an outer peripheral portion of a cylindrical housing portion for housing the filter;
The pneumatic feeder is configured to be capable of pumping cooling air into the cooling passage,
The exhaust purification device according to any one of claims 1 to 5, and the supplementary notes (i) and (b), wherein the discharge passage communicates with the cooling passage and discharges cooling air that has passed through the cooling passage.
According to the said structure, the temperature of exhaust gas can be reduced, suppressing the overheating of the accommodating part at the time of regeneration of a filter.

  DESCRIPTION OF SYMBOLS 10 ... Engine, 11 ... Exhaust passage, 12 ... Accommodating part, 13 ... Diameter reducing part, 14 ... Exhaust pipe, 15 ... 1st exhaust port, 20 ... Exhaust gas purification apparatus, 21 ... Mixer, 22 ... Pre-stage oxidation catalyst, 23 ... Filter 24, latter stage oxidation catalyst 30, burner 31, combustion section 32, fuel supply section 33, fuel tank 34, pump 35, fuel supply path 36, air supply section 37, first pneumatic feed 38 ... Combustion air supply path, 39 ... Glow plug, 40 ... Cooling part, 41 ... First outer cylinder part, 42 ... First cooling passage, 43 ... First connection passage, 45 ... Second outer cylinder part, 46 ... 2nd cooling passage, 47 ... 3rd outer cylinder part, 48 ... 3rd cooling passage, 50 ... 2nd pneumatic feeder, 51 ... 2nd connection passage, 55 ... Discharge head, 58 ... Discharge passage, 59 ... Introduction 60, discharge port, 60a ... discharge surface, 64 ... outside air guide member, 65 ... second Outlet, 66 ... Outside air guide passage, 67 ... Induction port, 68 ... Supply port, 69 ... Connection piece, 70 ... BCU, 71 ... Battery, 72 ... AC-DC converter, 73 ... External AC power supply, 75 ... ECU, 76 ... Temperature sensor.

Claims (5)

A filter that is disposed in the exhaust passage and captures particulate matter contained in the exhaust gas;
A burner for regenerating the filter by supplying combustion gas obtained by burning fuel to the filter;
A pneumatic feeder driven during regeneration of the filter;
A discharge passage having a discharge port for discharging cooling air pressure-fed by the pneumatic feeder, the discharge passage being disposed in parallel with a terminal portion of the exhaust passage and directed to exhaust gas discharged from the discharge port of the exhaust passage An exhaust purification device comprising: the discharge passage in which the discharge direction is set. The exhaust emission control device according to claim 1, wherein the discharge passage has the discharge direction set toward the center of the discharge port in a plan view from a direction facing the discharge port. The exhaust emission control device according to claim 1, wherein the discharge passage has a linear shape with a constant flow path cross-sectional area. A plurality of the discharge passages;
The exhaust emission control device according to any one of claims 1 to 3, wherein the discharge ports are arranged at equal intervals in a circumferential direction of the discharge port. A cylindrical outside air guide member surrounding the first discharge port, which is the discharge port, and the discharge passage;
The outside air guide member forms a second discharge port at a position opposite to the first discharge port, and is located outside the discharge passage and flows from the first discharge port toward the second discharge port. The exhaust emission control device according to any one of claims 1 to 4, wherein an outside air guide passage for guiding outside air attracted by gas is formed.