WO2012164661A1 - Exhaust gas purification device for internal combustion engine - Google Patents

Exhaust gas purification device for internal combustion engine Download PDF

Info

Publication number
WO2012164661A1
WO2012164661A1 PCT/JP2011/062369 JP2011062369W WO2012164661A1 WO 2012164661 A1 WO2012164661 A1 WO 2012164661A1 JP 2011062369 W JP2011062369 W JP 2011062369W WO 2012164661 A1 WO2012164661 A1 WO 2012164661A1
Authority
WO
WIPO (PCT)
Prior art keywords
air
fuel
fuel ratio
temperature
ratio
Prior art date
Application number
PCT/JP2011/062369
Other languages
French (fr)
Japanese (ja)
Inventor
伊藤　和浩
中山　茂樹
広田　信也
村田　宏樹
昂章 中村
Original Assignee
トヨタ自動車株式会社
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by トヨタ自動車株式会社 filed Critical トヨタ自動車株式会社
Priority to PCT/JP2011/062369 priority Critical patent/WO2012164661A1/en
Publication of WO2012164661A1 publication Critical patent/WO2012164661A1/en

Links

Images

Classifications

    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
    • F01N—GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES OR ENGINES IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNAL COMBUSTION ENGINES
    • F01N3/00—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust
    • F01N3/08—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for rendering innocuous
    • F01N3/0807—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for rendering innocuous by using absorbents or adsorbents
    • F01N3/0814—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for rendering innocuous by using absorbents or adsorbents combined with catalytic converters, e.g. NOx absorption/storage reduction catalysts
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
    • F01N—GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES OR ENGINES IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNAL COMBUSTION ENGINES
    • F01N3/00—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust
    • F01N3/08—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for rendering innocuous
    • F01N3/0807—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for rendering innocuous by using absorbents or adsorbents
    • F01N3/0828—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for rendering innocuous by using absorbents or adsorbents characterised by the absorbed or adsorbed substances
    • F01N3/0842—Nitrogen oxides
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
    • F01N—GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES OR ENGINES IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNAL COMBUSTION ENGINES
    • F01N3/00—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust
    • F01N3/08—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for rendering innocuous
    • F01N3/0807—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for rendering innocuous by using absorbents or adsorbents
    • F01N3/0871—Regulation of absorbents or adsorbents, e.g. purging
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
    • F01N—GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES OR ENGINES IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNAL COMBUSTION ENGINES
    • F01N3/00—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust
    • F01N3/08—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for rendering innocuous
    • F01N3/10—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for rendering innocuous by thermal or catalytic conversion of noxious components of exhaust
    • F01N3/18—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for rendering innocuous by thermal or catalytic conversion of noxious components of exhaust characterised by methods of operation; Control
    • F01N3/20—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for rendering innocuous by thermal or catalytic conversion of noxious components of exhaust characterised by methods of operation; Control specially adapted for catalytic conversion ; Methods of operation or control of catalytic converters
    • F01N3/2006—Periodically heating or cooling catalytic reactors, e.g. at cold starting or overheating
    • F01N3/2033—Periodically heating or cooling catalytic reactors, e.g. at cold starting or overheating using a fuel burner or introducing fuel into exhaust duct
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
    • F01N—GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES OR ENGINES IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNAL COMBUSTION ENGINES
    • F01N3/00—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust
    • F01N3/08—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for rendering innocuous
    • F01N3/10—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for rendering innocuous by thermal or catalytic conversion of noxious components of exhaust
    • F01N3/24—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for rendering innocuous by thermal or catalytic conversion of noxious components of exhaust characterised by constructional aspects of converting apparatus
    • F01N3/36—Arrangements for supply of additional fuel
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
    • F01N—GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES OR ENGINES IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNAL COMBUSTION ENGINES
    • F01N2240/00—Combination or association of two or more different exhaust treating devices, or of at least one such device with an auxiliary device, not covered by indexing codes F01N2230/00 or F01N2250/00, one of the devices being
    • F01N2240/14—Combination or association of two or more different exhaust treating devices, or of at least one such device with an auxiliary device, not covered by indexing codes F01N2230/00 or F01N2250/00, one of the devices being a fuel burner
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02T—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO TRANSPORTATION
    • Y02T10/00—Road transport of goods or passengers
    • Y02T10/10—Internal combustion engine [ICE] based vehicles
    • Y02T10/12—Improving ICE efficiencies

Definitions

  • the present invention relates to an exhaust purification device for an internal combustion engine.
  • a technology is known in which a burner having a fuel supply device and an ignition device is provided in the exhaust passage upstream of the selective reduction type NOx catalyst, and the burner is activated for early activation of the NOx catalyst when the internal combustion engine is cold started. (For example, refer to Patent Document 1). By burning the fuel with this burner and raising the temperature of the exhaust, the temperature of the NOx catalyst can be raised.
  • exhaust is provided by providing a region where the fuel is burned so that the excess air ratio is less than 1, and a region where the excess air ratio is greater than 1 on the downstream side.
  • a technique for removing contained harmful substances is known (for example, see Patent Document 2). In this technique, the fuel amount and the air amount are adjusted so that the temperature in the burner is higher than 1300 ° C. and lower than 1500 ° C.
  • a fuel addition valve and a glow plug are provided upstream of the catalyst, and the fuel added from the fuel addition valve is heated by the glow plug, thereby generating an activated substance and supplying the activated substance to the catalyst.
  • a technique is known (for example, refer to Patent Document 3).
  • the present invention aims to reduce the amount of NOx and smoke generated in the temperature raising device.
  • an exhaust gas purification apparatus for an internal combustion engine comprises: An exhaust purification catalyst provided in the exhaust passage of the internal combustion engine; A temperature raising device provided in an exhaust passage upstream of the exhaust purification catalyst; An exhaust gas purification apparatus for an internal combustion engine comprising: The temperature raising device includes an air supply device that supplies air, a fuel injection valve that supplies fuel, and a combustion chamber that burns an air-fuel mixture of the air and the fuel, When the air-fuel mixture is burned in the combustion chamber, the air-fuel ratio that is the ratio of the air and the fuel in the air-fuel mixture is made richer than the stoichiometric air-fuel ratio, and the ratio of the fuel in the air-fuel mixture Is provided with an air-fuel ratio control device that makes the ratio larger than the ratio when the generation amount of soot becomes maximum.
  • the air-fuel ratio of the air-fuel mixture burned by the temperature raising device is made lower than the air-fuel ratio at which the amount of soot is maximized.
  • the amount of soot increases, but when the fuel ratio exceeds a certain ratio, the amount of soot decreases. That is, there is an air-fuel ratio at which the amount of soot is maximized, and the generation of soot can be suppressed by making the fuel ratio larger than this air-fuel ratio. That is, an increase in smoke can be suppressed.
  • the combustion in the temperature raising device can include oxidizing the fuel. That is, for example, an ignition device may be provided, and the fuel may be burned by the ignition device, or the fuel may be burned by being oxidized by oxygen contained in the air supplied from the air supply device.
  • an air-fuel ratio detection device for detecting the air-fuel ratio of the air-fuel mixture can be provided in the combustion chamber.
  • the air-fuel ratio in the temperature raising device can be detected with high accuracy by providing the air-fuel ratio detection device in the combustion chamber. Thereby, since the control of the fuel ratio can be performed with high accuracy, the generation of NOx and smoke can be further suppressed.
  • the air-fuel ratio detecting device since the temperature of the combustion gas becomes higher on the downstream side than the outlet of the combustion chamber, if the air-fuel ratio detecting device is provided on the downstream side of the outlet of the combustion chamber, the air-fuel ratio detecting device may be deteriorated. On the other hand, by providing the air-fuel ratio detection device in the combustion chamber, deterioration of the air-fuel ratio detection device can be suppressed. Further, since condensed water may be generated in the exhaust passage of the internal combustion engine, when an air-fuel ratio detection device is attached to the exhaust passage, the condensed water adheres to the air-fuel ratio detection device, and the performance of the air-fuel ratio detection device is reduced. May decrease. On the other hand, it can suppress that condensed water adheres by providing an air fuel ratio detection apparatus in a combustion chamber.
  • an air-fuel ratio detection device may be provided at a position where the flame does not directly hit in the combustion chamber. Thereby, deterioration of an air fuel ratio detection apparatus can be suppressed more.
  • the air-fuel ratio detection device may be provided on the outlet side of the combustion chamber with respect to the fuel injection valve. As a result, the air-fuel ratio after the air and fuel are mixed can be detected, so that the air-fuel ratio detection accuracy can be further improved.
  • the air-fuel ratio detection device may be provided at a position through which the air-fuel mixture passes. Even in this case, since the air-fuel ratio after the air and fuel are mixed can be detected, the air-fuel ratio detection accuracy can be further improved.
  • an air-fuel ratio estimating device for estimating the air-fuel ratio in the combustion chamber when the air-fuel ratio cannot be detected by the air-fuel ratio detecting device can be provided.
  • some air-fuel ratio detection devices cannot detect the air-fuel ratio until the element is activated. In a state where the air-fuel ratio cannot be detected, for example, feedback control cannot be performed, so that the air-fuel ratio may deviate from the target value. In contrast, by estimating the air-fuel ratio, it is possible to suppress the air-fuel ratio from deviating from the target value.
  • the air-fuel ratio can be estimated, for example, by estimating the air amount and the fuel amount.
  • a temperature detection device for detecting the temperature of the exhaust purification catalyst The air-fuel ratio control device theoretically calculates an air-fuel ratio that is a ratio of the air and the fuel in the air-fuel mixture when the temperature detected by the temperature detection device is equal to or higher than the activation temperature of the exhaust purification catalyst. It is possible to make the fuel richer than the air-fuel ratio and to make the ratio of the fuel in the air-fuel mixture larger than the ratio when the generation amount of soot is maximized.
  • the ratio of the fuel it is possible to supply a fuel that easily reacts with the catalyst.
  • the temperature of the catalyst does not reach the activation temperature, it becomes difficult to react the fuel.
  • the unburned fuel that has reached the catalyst can be reacted, so that the unburned fuel is prevented from accumulating on the catalyst. it can. It is also possible to prevent unburned fuel from passing through the catalyst.
  • the amount of air and the amount of fuel may be adjusted so that the air-fuel ratio of the air-fuel mixture becomes the lean air-fuel ratio. Thereby, it can suppress that unburned fuel flows in into an exhaust gas purification catalyst.
  • the air-fuel ratio control device controls the air-fuel mixture so that the combustion temperature is 200 ° C. or higher and 1500 ° C. or lower, and the air-fuel ratio is 1.5 or higher and less than the stoichiometric air-fuel ratio. Can be generated. By burning the fuel in such a state, the above effect can be further enhanced.
  • the amount of NOx and smoke generated in the temperature raising device can be reduced.
  • FIG. 1 It is a figure which shows schematic structure of the exhaust gas purification apparatus of the internal combustion engine which concerns on an Example. It is an expanded sectional view of a temperature rising device. It is the figure which showed the relationship between the combustion temperature and air fuel ratio in a temperature rising apparatus. It is the figure which showed the relationship between the air fuel ratio in a combustion chamber, and the average value (average temperature) of combustion temperature. It is the figure which showed the relationship between the air fuel ratio in a combustion chamber, and smoke concentration. It is the flowchart which showed the control flow of the temperature rising apparatus which concerns on an Example. It is sectional drawing of the temperature raising apparatus which installed the combustion chamber outside the exhaust passage. It is a figure which shows schematic structure of the exhaust gas purification apparatus of the internal combustion engine provided with the mixer which concerns on an Example.
  • FIG. 1 is a diagram showing a schematic configuration of an exhaust gas purification apparatus for an internal combustion engine according to the present embodiment.
  • the internal combustion engine 1 shown in FIG. 1 may be a diesel engine or a gasoline engine.
  • the exhaust passage 2 is connected to the internal combustion engine 1.
  • An exhaust purification catalyst 3 (hereinafter simply referred to as “catalyst 3”) is provided in the middle of the exhaust passage 2.
  • the catalyst 3 include an occlusion reduction type NOx catalyst, a selective reduction type NOx catalyst, a three-way catalyst, and an oxidation catalyst.
  • the catalyst 3 may be a catalyst having an oxidation function.
  • a particulate filter that collects particulate matter may be provided, and the particulate filter may be used as the carrier of the catalyst 3.
  • a temperature raising device 4 is provided in the exhaust passage 2 upstream of the catalyst 3.
  • the temperature raising device 4 includes a combustion chamber 41 provided in the exhaust passage 2, an air supply pipe 42 for supplying air to the combustion chamber 41, a pump 43 for discharging air, and an injection for injecting fuel into the combustion chamber 41.
  • the valve 44 includes an ignition device 45 that ignites an air-fuel mixture of fuel and air.
  • the air supply pipe 42 and the pump 43 correspond to the air supply device in the present invention.
  • the injection valve 44 corresponds to the fuel injection valve in the present invention.
  • FIG. 2 is an enlarged sectional view of the temperature raising device 4.
  • the combustion chamber 41 is formed so as to have an outer diameter smaller than the inner diameter of the exhaust passage 2 and a cylindrical shape coaxial with the central axis of the exhaust passage 2.
  • the combustion chamber 41 is closed on the upstream side of the exhaust flow, and is opened at the opening 411 on the downstream side.
  • a downstream end portion of the combustion chamber 41 is provided with a throttle portion 412 having a diameter that decreases toward the downstream side.
  • a pump 43 is connected to the combustion chamber 41 via an air supply pipe 42.
  • the pump 43 includes an electric motor, for example, and discharges air according to the number of rotations. Air is supplied to the combustion chamber 41 by operating the pump 43 to discharge air.
  • the pump 43 may obtain driving force from the crankshaft of the internal combustion engine 1. Further, the pump 43 may control the amount of air discharged by controlling the number of rotations, and controls the amount of air discharged by adjusting the operation time and the stop time. May be.
  • air is discharged from the pump 43, but instead of this, the exhaust gas (EGR gas) of the internal combustion engine 1 may be discharged.
  • the EGR gas and air may be mixed and discharged.
  • a gas obtained by adding carbon dioxide to air may be discharged. These are gases that suppress the oxidation of the fuel, and by supplying these gases, the low-temperature combustion region described later can be expanded.
  • the air supply pipe 42 is provided with a pressure sensor 11 that detects the pressure in the air supply pipe 42.
  • an ignition device 45 is attached in a range where the fuel 47 injected from the injection valve 44 reaches.
  • the ignition device 45 for example, a glow plug or a spark plug can be used.
  • the injection valve 44 injects a combustible agent such as light oil, gasoline, synthetic oil, propane gas, or hydrogen.
  • An upstream temperature sensor 12 for detecting the temperature in the exhaust passage 2 is attached to the exhaust passage 2 downstream from the temperature raising device 4 and upstream from the catalyst 3.
  • a downstream temperature sensor 13 for detecting the temperature in the exhaust passage 2 is attached to the exhaust passage 2 downstream of the catalyst 3.
  • the internal combustion engine 1 configured as described above is provided with an ECU 10 that is an electronic control unit for controlling the internal combustion engine 1.
  • the ECU 10 controls the internal combustion engine 1 in accordance with the operating conditions of the internal combustion engine 1 and the driver's request.
  • the ECU 10 is connected to the sensor via electrical wiring, and an output signal of the sensor is input.
  • a pump 43, an injection valve 44, and an ignition device 45 are connected to the ECU 10 via electric wiring, and these are controlled by the ECU 10.
  • the ECU 10 operates the temperature raising device 4 by injecting fuel from the injection valve 44 while operating the pump 43 and the ignition device 45.
  • the flame 48 is generated by igniting the air-fuel mixture.
  • the ECU 10 controls the air-fuel ratio and the combustion temperature in the combustion chamber 41 by adjusting the amount of fuel and air supplied to the combustion chamber 41 when the temperature raising device 4 is operated.
  • the ECU 10 performs low temperature combustion in the combustion chamber 41. This low-temperature combustion is combustion at an air-fuel ratio that is a rich air-fuel ratio and has a fuel ratio larger than the air-fuel ratio at which the amount of soot is maximized.
  • FIG. 3 is a diagram showing the relationship between the combustion temperature and the air-fuel ratio in the temperature raising device 4.
  • the vertical axis is the air-fuel ratio
  • the horizontal axis is the combustion temperature.
  • an area described as “SOOT” is an area where wrinkles are generated relatively more than other areas.
  • the region described as “NOx” is a region where a relatively large amount of NOx is generated as compared with other regions.
  • region where an air fuel ratio is larger than a dashed-dotted line or combustion temperature is low is an area
  • a region where the temperature raising device 4 is operated, and a region where the air-fuel ratio is lower than the stoichiometric air-fuel ratio indicated by a broken line is a region where low-temperature combustion is performed.
  • regeneration is an area
  • the pump 43 and the injection valve 44 are controlled so that the air-fuel ratio becomes a value between 1.5 and 32 and the combustion temperature becomes a value between 200 ° C. and 1500 ° C. Then, since the combustion temperature is low, the generation of NOx can be suppressed. Moreover, since the combustion temperature is low, it can suppress that the temperature of the catalyst 3 rises excessively. Furthermore, when low-temperature combustion is performed, a large amount of unburned fuel is discharged, but this unburned fuel is reformed into a light fuel. By reforming the fuel in this way, the reaction of the fuel in the catalyst 3 can be promoted, so that the temperature of the catalyst 3 can be easily increased. Moreover, since the unburned fuel discharged when performing low temperature combustion has high reactivity, it can suppress that a fuel adheres to the catalyst 3. FIG.
  • FIG. 4 is a diagram showing the relationship between the air-fuel ratio in the combustion chamber 41 and the average value (average temperature) of the combustion temperature.
  • 10 g / s, 15 g / s, 20 g / s, 25 g / s, and 30 g / s indicate the amounts of air, respectively.
  • the combustion temperature varies with the amount of air even if the air-fuel ratio is the same.
  • the air-fuel ratio can be kept constant by controlling the amount of fuel in accordance with the amount of air. Therefore, by adjusting the air amount and the fuel amount, for example, the combustion temperature can be changed without changing the air-fuel ratio.
  • FIG. 5 is a diagram showing the relationship between the air-fuel ratio in the combustion chamber 41 and the smoke concentration.
  • 10 L / min, 15 L / min, 20 L / min, 25 L / min, 35 L / min, 45 L / min, and 50 L / min indicate the amounts of air, respectively.
  • the smoke concentration changes depending on the air-fuel ratio. Furthermore, it can be seen that there is a maximum value in the smoke concentration.
  • low-temperature combustion can be performed by adjusting the air amount and the fuel amount so that the air-fuel ratio becomes lower than the air-fuel ratio at which the smoke concentration becomes the maximum value.
  • the low-temperature combustion may be performed when the temperature of the catalyst 3 is equal to or higher than the activation temperature.
  • the activation temperature can be a temperature at which unburned fuel discharged by low temperature combustion can be oxidized. Whether or not the catalyst 3 has been activated can be determined by, for example, the upstream temperature sensor 12 or the downstream temperature sensor 13.
  • a catalyst is provided in addition to the catalyst 3, it may be determined whether or not the temperature of the catalyst 3 is equal to or higher than the activation temperature based on the temperature of the catalyst.
  • the temperature of the catalyst 3 can be estimated based on the operating state of the internal combustion engine 1. For example, the temperature of the catalyst 3 can be estimated based on the engine speed, the accelerator opening, the fuel injection amount, the estimated torque, and the like.
  • the temperature of the catalyst 3 can also be estimated using a known technique.
  • the ECU 10 that estimates the temperature of the catalyst 3 or the downstream temperature sensor 13 corresponds to the temperature detection device in the present invention.
  • an air-fuel ratio sensor 46 is provided in the combustion chamber 41.
  • the air-fuel ratio sensor 46 can detect the air-fuel ratio in the combustion chamber 41. Then, for example, feedback control of at least one of the fuel injection amount from the injection valve 44 or the air amount discharged from the pump 43 is performed so that the detected air-fuel ratio becomes the target value.
  • the air-fuel ratio sensor 46 corresponds to the air-fuel ratio detection device in the present invention.
  • the air-fuel ratio sensor 46 is attached in the vicinity of the downstream end of the combustion chamber 41, that is, in the vicinity of the opening 411 of the combustion chamber 41 and at a location that is not easily affected by the exhaust gas of the internal combustion engine 1.
  • the part that is hardly affected by the exhaust of the internal combustion engine 1 is a part where the exhaust from the internal combustion engine 1 does not circulate, for example.
  • the air-fuel ratio sensor 46 is attached to a location where the air-fuel mixture flows. Further, if the distance is too close to the opening 411, the temperature of the air-fuel ratio sensor 46 becomes excessively high and the air-fuel ratio sensor 46 may be deteriorated.
  • the air-fuel ratio sensor 46 is attached downstream of the injection valve 44 and upstream of the throttle portion 412. The optimum position for attaching the air-fuel ratio sensor 46 may be obtained by experiments or the like.
  • the air-fuel ratio sensor 46 By thus installing the air-fuel ratio sensor 46 in the combustion chamber 41, the air-fuel ratio in the combustion chamber 41 can be controlled more precisely. As a result, the amount of smoke and NOx produced can be further reduced. Further, even when an error occurs in the air amount or the fuel injection amount due to individual differences or aging of the pump 43 or the injection valve 44, these can be corrected. Furthermore, by installing the air-fuel ratio sensor 46 in the combustion chamber 41, it becomes difficult for high-temperature combustion gas to hit the air-fuel ratio sensor 46, so that deterioration of the air-fuel ratio sensor 46 can be suppressed. Further, failure detection of the temperature raising device 4 can be performed based on the detection value of the air-fuel ratio sensor 46.
  • the air-fuel ratio sensor 46 incorporates a heater for activating the element. Electric power is supplied when the temperature of the element is raised by this heater.
  • the air-fuel ratio sensor 46 is installed in the combustion chamber 41 so that heat generated by the combustion is supplied to the air-fuel ratio sensor 6. For this reason, the electric power for raising the temperature of the element of the air-fuel ratio sensor 46 can be reduced. Thereby, fuel consumption can be improved.
  • the inside of the combustion chamber 41 opens toward the downstream side of the exhaust flow, the condensed water generated in the exhaust passage 2 is difficult to enter the combustion chamber 41. For this reason, it is possible to prevent the condensed water from adhering to the air-fuel ratio sensor 46. Thereby, it can suppress that the air fuel ratio sensor 46 deteriorates.
  • the air-fuel ratio sensor 46 detects the value of the air-fuel ratio of the air-fuel mixture. Alternatively, the output value may change with the stoichiometric air-fuel ratio as a boundary.
  • the temperature raising device 4 may be operated after the element is activated and the air-fuel ratio sensor 46 can detect the air-fuel ratio.
  • the air-fuel ratio in the combustion chamber 41 may be estimated while the air-fuel ratio sensor 46 cannot detect the air-fuel ratio. Then, the air amount or the fuel injection amount may be controlled based on the estimated value of the air-fuel ratio.
  • the air-fuel ratio for example, an air amount and a fuel injection amount are estimated. The amount of air is based on, for example, the number of rotations of the pump 43, the pressure in the air supply pipe 42, the temperature in the air supply pipe 42, the flow rate of air flowing into the pump 43, or the flow rate of air flowing out of the pump 43. Can be estimated. These values can be detected by attaching a sensor.
  • the air amount can be estimated based on the map.
  • the calculation formula of air quantity may be memorize
  • a known technique can also be used for estimating the air amount.
  • the fuel injection amount can be estimated based on the valve opening time of the injection valve 44, the fuel flow rate, the fuel pressure, and the like.
  • the valve opening time of the injection valve 44 may be obtained from a command value calculated by the ECU 10.
  • the fuel flow rate and fuel pressure can be detected by installing a sensor. For example, if the relationship between these values and the fuel injection amount is mapped and stored in the ECU 10, the fuel injection amount can be estimated based on the map.
  • a calculation formula for the fuel injection amount may be stored in the ECU 10 and the fuel injection amount may be estimated based on the calculation formula.
  • a known technique can also be used for estimating the fuel injection amount.
  • the air-fuel ratio can be estimated by calculating the ratio between the air amount estimated in this way and the fuel injection amount.
  • the air-fuel ratio cannot be detected by the air-fuel ratio sensor 46, the generation of NOx and smoke can be suppressed by controlling the fuel injection amount or the air amount using the estimated value of the air-fuel ratio.
  • the ECU 10 that estimates the air-fuel ratio corresponds to the air-fuel ratio estimation device in the present invention.
  • the air amount or the fuel injection amount may be adjusted in the temperature raising device 4 so that the lean air-fuel ratio is obtained. Thereby, it can suppress that unburned fuel is discharged
  • the temperature raising device 4 can be used not only for raising the temperature of the catalyst 3 but also for oxidizing the PM collected by the filter. That is, PM can be oxidized by heat generated when the unburned fuel is oxidized by the catalyst 3.
  • FIG. 6 is a flowchart showing a control flow of the temperature raising device 4 according to the present embodiment. This routine is executed by the ECU 10 every predetermined time.
  • step S101 it is determined whether the catalyst 3 is active. For example, the temperature of the catalyst 3 is detected by the downstream temperature sensor 13, and when the temperature is equal to or higher than the activation temperature, it is determined that the catalyst 3 is active. In this step, it is determined whether the unburned fuel is oxidized by the catalyst 3 when the unburned fuel is supplied to the catalyst 3.
  • step S101 If an affirmative determination is made in step S101, the process proceeds to step S104. On the other hand, if a negative determination is made, the process proceeds to step S102.
  • step S102 the temperature raising device 4 is operated with the target air-fuel ratio as the lean air-fuel ratio. That is, since the unburned fuel cannot be oxidized because the catalyst 3 is not activated, the temperature of the catalyst 3 is raised while preventing the unburned fuel from reaching the catalyst 3.
  • the air-fuel ratio at this time is set to 32 or less, for example.
  • the combustion temperature is, for example, 200 ° C. or more and 1500 ° C. or less. Thereby, generation
  • step S103 it is determined whether or not the catalyst 3 is active. In this step, the same processing as in step S101 is performed. If an affirmative determination is made in step S103, the process proceeds to step S104, and if a negative determination is made, the process returns to step S102.
  • step S104 the temperature raising device 4 performs low temperature combustion. Thereby, the unburned fuel which became light can be supplied to the catalyst 3. As a result, the temperature of the catalyst 3 can be further increased. In addition, when a particulate filter is provided, PM can be removed from the particulate filter by increasing the temperature of the catalyst 3.
  • the ECU 10 that processes step S104 corresponds to the air-fuel ratio control apparatus according to the present invention.
  • combustion chamber 41 is installed inside the exhaust passage 2, but instead, the combustion chamber 41 may be installed outside the exhaust passage 2. Then, the outlet of the combustion chamber 41 may be connected to the exhaust passage 2.
  • FIG. 7 is a cross-sectional view of the temperature raising device 400 in which the combustion chamber 401 is installed outside the exhaust passage 2.
  • an opening 402 is provided in the combustion chamber 401, and a hole 21 is also provided in the exhaust passage 2 along with the opening 402.
  • an air-fuel ratio sensor 46, an ignition device 45, an injection valve 44, and an air supply pipe 42 are attached in this order from the opening 402 side. Even with such a configuration, low-temperature combustion can be performed.
  • a mixer 5 for stirring the exhaust gas may be provided upstream or downstream of the temperature raising device 4.
  • FIG. 8 is a diagram showing a schematic configuration of an exhaust gas purification apparatus for an internal combustion engine provided with the mixer 5 according to the present embodiment.
  • the mixer 5 is attached downstream of the combustion chamber 41 and upstream of the upstream temperature sensor 12.
  • the mixer 5 includes, for example, a plurality of plates that change the direction of the exhaust flow. By providing such a mixer 5, unburned fuel in the exhaust can be uniformly dispersed. Further, the exhaust temperature can be made uniform.
  • the mixer 5 may be provided upstream from the combustion chamber 41.
  • the temperature raising device 4 when the temperature of the catalyst 3 is raised, the temperature raising device 4 performs low temperature combustion, thereby reducing the amount of NOx and smoke generated. Thereby, the temperature of the catalyst 3 can be raised while reducing the amount of PM and NOx flowing into the catalyst 3. Moreover, since heavy HC can be changed into light HC, the reaction of HC in the catalyst 3 can be promoted. Thereby, the temperature of the catalyst 3 can be raised rapidly. It is also possible to suppress the catalyst 3 from being clogged with unburned fuel. In addition, since highly reactive CO can be generated, more heat of reaction can be obtained in the catalyst 3, so that the temperature of the catalyst 3 can be easily increased. Further, since the amount of air supplied to the temperature raising device 4 can be relatively reduced, the power supplied to the pump 43 can be reduced.
  • the air-fuel ratio sensor 46 in the combustion chamber 41, the air-fuel ratio can be detected with high accuracy, and deterioration of the air-fuel ratio sensor 46 can be suppressed. Thereby, low temperature combustion can be performed more easily in the temperature raising device 4.

Landscapes

  • Engineering & Computer Science (AREA)
  • Chemical & Material Sciences (AREA)
  • Combustion & Propulsion (AREA)
  • Mechanical Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Health & Medical Sciences (AREA)
  • Toxicology (AREA)
  • Exhaust Gas After Treatment (AREA)

Abstract

In order to reduce the amount of generation of NOx and smoke by a temperature raising device, an exhaust gas purification device for an internal combustion engine is provided with an exhaust gas purification catalyst (3) and the temperature raising device (4) which is provided in the portion of the exhaust path (2) which is located upstream of the exhaust gas purification catalyst (3). The temperature raising device (4) comprises an air supply device (42, 43) which supply air, a fuel injection valve (44) which supplies fuel, and a combustion chamber (41) which combusts a mixture gas of the air and the fuel. The exhaust gas purification device is also provided with an air-fuel ratio control device (10) configured so that, when combusting the mixture gas in the combustion chamber (41), the air-fuel ratio control device (10) sets the air-fuel ratio, which is the ratio between the air and fuel in the mixture gas, to the side richer than a theoretical air-fuel ratio and also sets the proportion of the fuel in the mixture gas to a level greater than the proportion when the amount of generation of soot is maximum.

Description

内燃機関の排気浄化装置Exhaust gas purification device for internal combustion engine
　本発明は、内燃機関の排気浄化装置に関する。 The present invention relates to an exhaust purification device for an internal combustion engine.
　選択還元型ＮＯx触媒よりも上流側の排気通路に燃料供給装置及び着火装置を備えたバーナを設け、内燃機関の冷間始動時に、ＮＯx触媒の早期活性化のためにバーナを作動させる技術が知られている（例えば、特許文献１参照。）。このバーナにより燃料を燃焼させて排気の温度を上昇させることで、ＮＯx触媒の温度を上昇させることができる。 A technology is known in which a burner having a fuel supply device and an ignition device is provided in the exhaust passage upstream of the selective reduction type NOx catalyst, and the burner is activated for early activation of the NOx catalyst when the internal combustion engine is cold started. (For example, refer to Patent Document 1). By burning the fuel with this burner and raising the temperature of the exhaust, the temperature of the NOx catalyst can be raised.
　また、バーナの燃焼室内に空気過剰率が１未満となるようにして燃料を燃焼させる領域と、さらに下流側に空気過剰率が１よりも大きくなるようにする領域と、を設けることで排気に含まれる有害物質を除去する技術が知られている（例えば、特許文献２参照。）。この技術では、バーナ内の温度が１３００℃よりも高く、１５００℃よりも低くなるように燃料量及び空気量が調整される。 In addition, in the combustion chamber of the burner, exhaust is provided by providing a region where the fuel is burned so that the excess air ratio is less than 1, and a region where the excess air ratio is greater than 1 on the downstream side. A technique for removing contained harmful substances is known (for example, see Patent Document 2). In this technique, the fuel amount and the air amount are adjusted so that the temperature in the burner is higher than 1300 ° C. and lower than 1500 ° C.
　また、触媒よりも上流側に燃料添加弁及びグロープラグを設け、燃料添加弁から添加される燃料をグロープラグで加熱することにより、活性化物質を生成させ、該活性化物質を触媒へ供給する技術が知られている（例えば、特許文献３参照。）。 In addition, a fuel addition valve and a glow plug are provided upstream of the catalyst, and the fuel added from the fuel addition valve is heated by the glow plug, thereby generating an activated substance and supplying the activated substance to the catalyst. A technique is known (for example, refer to Patent Document 3).
　しかし、バーナでの燃焼が不安定となると、バーナからＮＯxまたは未燃燃料が排出される。そして、バーナから排出される未燃燃料が触媒に付着すると、排気の浄化性能が低下してしまう。また、バーナから排出されるＮＯxの量が、触媒で浄化可能なＮＯxの量を超えると、ＮＯxが触媒をすり抜けてしまう。また、バーナで粒子状物質（以下、ＰＭともいう。）が生成されることにより、スモークが増加する虞がある。 However, when combustion in the burner becomes unstable, NOx or unburned fuel is discharged from the burner. And if the unburned fuel discharged from the burner adheres to the catalyst, the exhaust purification performance will deteriorate. In addition, when the amount of NOx discharged from the burner exceeds the amount of NOx that can be purified by the catalyst, NOx passes through the catalyst. Further, smoke is likely to increase due to the generation of particulate matter (hereinafter also referred to as PM) by the burner.
特開２００９－０６８４２４号公報JP 2009-068424 A 特開２００６－１９４２５４号公報JP 2006-194254 A 特開２０１０－１６３９６７号公報JP 2010-163967 A
　本発明は、昇温装置におけるＮＯx及びスモークの発生量を低減することを目的とする。 The present invention aims to reduce the amount of NOx and smoke generated in the temperature raising device.
　上記課題を達成するために本発明による内燃機関の排気浄化装置は、
　内燃機関の排気通路に設けられる排気浄化触媒と、
　前記排気浄化触媒よりも上流の排気通路に設けられる昇温装置と、
　を備える内燃機関の排気浄化装置において、
　前記昇温装置は、空気を供給する空気供給装置、燃料を供給する燃料噴射弁、前記空気と前記燃料との混合気を燃焼させる燃焼室を備えて構成され、
　前記燃焼室において前記混合気を燃焼させるときに、前記混合気中の前記空気と前記燃料との比である空燃比を理論空燃比よりもリッチ側とし、且つ、前記混合気中の燃料の割合を、煤の発生量が最大となるときの割合よりも大きくする空燃比制御装置を備える。 In order to achieve the above object, an exhaust gas purification apparatus for an internal combustion engine according to the present invention comprises:
An exhaust purification catalyst provided in the exhaust passage of the internal combustion engine;
A temperature raising device provided in an exhaust passage upstream of the exhaust purification catalyst;
An exhaust gas purification apparatus for an internal combustion engine comprising:
The temperature raising device includes an air supply device that supplies air, a fuel injection valve that supplies fuel, and a combustion chamber that burns an air-fuel mixture of the air and the fuel,
When the air-fuel mixture is burned in the combustion chamber, the air-fuel ratio that is the ratio of the air and the fuel in the air-fuel mixture is made richer than the stoichiometric air-fuel ratio, and the ratio of the fuel in the air-fuel mixture Is provided with an air-fuel ratio control device that makes the ratio larger than the ratio when the generation amount of soot becomes maximum.
　すなわち、昇温装置で燃焼させる混合気の空燃比を、煤の発生量が最大となる空燃比よりも低くする。ここで、燃料の割合を大きくすると、煤の発生量が増加するが、燃料の割合がある割合を超えると、煤の発生量が減少する。すなわち、煤の発生量が最大となる空燃比が存在し、この空燃比よりも燃料の割合を大きくすることで、煤の発生を抑制することができる。すなわち、スモークの増加を抑制できる。 That is, the air-fuel ratio of the air-fuel mixture burned by the temperature raising device is made lower than the air-fuel ratio at which the amount of soot is maximized. Here, when the fuel ratio is increased, the amount of soot increases, but when the fuel ratio exceeds a certain ratio, the amount of soot decreases. That is, there is an air-fuel ratio at which the amount of soot is maximized, and the generation of soot can be suppressed by making the fuel ratio larger than this air-fuel ratio. That is, an increase in smoke can be suppressed.
　このときには、昇温装置から未燃燃料が排出されるが、この未燃燃料は高温に晒されることにより、触媒にて反応しやすい状態となっている。すなわち、燃料噴射弁から噴射された燃料が、より軽質の燃料に変化する。このため、昇温装置にて生成される未燃燃料が触媒へ到達しても、該触媒にて未燃燃料が速やかに反応する。したがって、触媒に未燃燃料が堆積することを抑制できるため、該触媒の浄化性能が低下すること抑制できる。また、触媒にて燃料が速やかに反応するため、触媒の温度を速やかに上昇させることができる。 At this time, unburned fuel is discharged from the temperature raising device, but the unburned fuel is exposed to a high temperature, so that it easily reacts with the catalyst. That is, the fuel injected from the fuel injection valve changes to a lighter fuel. For this reason, even if unburned fuel produced | generated with a temperature rising apparatus reaches | attains a catalyst, unburned fuel reacts rapidly with this catalyst. Therefore, since it can suppress that unburned fuel accumulates on a catalyst, it can control that the purification performance of the catalyst falls. In addition, since the fuel reacts quickly in the catalyst, the temperature of the catalyst can be quickly raised.
　また、燃料の割合を大きくすることにより燃焼温度が低くなるので、ＮＯxの生成を抑制することができる。なお、昇温装置における燃焼には、燃料を酸化させることを含むことができる。すなわち、たとえば着火装置を備え、該着火装置によって燃料を燃焼させてもよいし、燃料を空気供給装置から供給される空気に含まれる酸素によって酸化させることにより燃焼させてもよい。 Also, since the combustion temperature is lowered by increasing the fuel ratio, the production of NOx can be suppressed. The combustion in the temperature raising device can include oxidizing the fuel. That is, for example, an ignition device may be provided, and the fuel may be burned by the ignition device, or the fuel may be burned by being oxidized by oxygen contained in the air supplied from the air supply device.
　また、本発明においては、前記燃焼室内に、前記混合気の空燃比を検出する空燃比検出装置を備えることができる。 In the present invention, an air-fuel ratio detection device for detecting the air-fuel ratio of the air-fuel mixture can be provided in the combustion chamber.
　燃焼室内では内燃機関からの排気の影響をほとんど受けないため、燃焼室内に空燃比検出装置を備えることにより、昇温装置内の空燃比を高精度に検出することができる。これにより、上記燃料の割合の制御を精度よく行うことができるため、ＮＯxやスモークが生成されることをより抑制できる。 Since the combustion chamber is hardly affected by the exhaust from the internal combustion engine, the air-fuel ratio in the temperature raising device can be detected with high accuracy by providing the air-fuel ratio detection device in the combustion chamber. Thereby, since the control of the fuel ratio can be performed with high accuracy, the generation of NOx and smoke can be further suppressed.
　また、燃焼室の出口よりも下流側では燃焼ガスの温度が高くなるので、燃焼室の出口よりも下流側に空燃比検出装置を備えると、該空燃比検出装置が劣化する虞がある。これに対し、燃焼室内に空燃比検出装置を備えることで、該空燃比検出装置の劣化を抑制できる。さらに、内燃機関の排気通路では凝縮水が発生することがあるので、排気通路に空燃比検出装置を取り付けると、該凝縮水が空燃比検出装置に付着して、該空燃比検出装置の性能が低下する虞がある。これに対し、燃焼室内に空燃比検出装置を備えることで、凝縮水が付着することを抑制できる。 Also, since the temperature of the combustion gas becomes higher on the downstream side than the outlet of the combustion chamber, if the air-fuel ratio detecting device is provided on the downstream side of the outlet of the combustion chamber, the air-fuel ratio detecting device may be deteriorated. On the other hand, by providing the air-fuel ratio detection device in the combustion chamber, deterioration of the air-fuel ratio detection device can be suppressed. Further, since condensed water may be generated in the exhaust passage of the internal combustion engine, when an air-fuel ratio detection device is attached to the exhaust passage, the condensed water adheres to the air-fuel ratio detection device, and the performance of the air-fuel ratio detection device is reduced. May decrease. On the other hand, it can suppress that condensed water adheres by providing an air fuel ratio detection apparatus in a combustion chamber.
　なお、燃焼室内において火炎が直接当たらない位置に空燃比検出装置を備えていてもよい。これにより、空燃比検出装置の劣化をより抑制できる。 Note that an air-fuel ratio detection device may be provided at a position where the flame does not directly hit in the combustion chamber. Thereby, deterioration of an air fuel ratio detection apparatus can be suppressed more.
　また、前記空燃比検出装置を、前記燃料噴射弁よりも該燃焼室の出口側に備えていてもよい。そうすると、空気と燃料とが混合された後の空燃比を検出することができるため、空燃比の検出精度をより高めることができる。 Further, the air-fuel ratio detection device may be provided on the outlet side of the combustion chamber with respect to the fuel injection valve. As a result, the air-fuel ratio after the air and fuel are mixed can be detected, so that the air-fuel ratio detection accuracy can be further improved.
　また、前記空燃比検出装置を、前記混合気が通過する位置に備えていてもよい。このようにしても、空気と燃料とが混合された後の空燃比を検出することができるため、空燃比の検出精度をより高めることができる。 Further, the air-fuel ratio detection device may be provided at a position through which the air-fuel mixture passes. Even in this case, since the air-fuel ratio after the air and fuel are mixed can be detected, the air-fuel ratio detection accuracy can be further improved.
　また、本発明においては、前記空燃比検出装置により空燃比の検出を行うことができないときに前記燃焼室内の空燃比を推定する空燃比推定装置を備えることができる。 In the present invention, an air-fuel ratio estimating device for estimating the air-fuel ratio in the combustion chamber when the air-fuel ratio cannot be detected by the air-fuel ratio detecting device can be provided.
　ここで、空燃比検出装置には、素子が活性化するまでは空燃比の検出ができないものも存在する。空燃比を検出することができない状態では、たとえばフィードバック制御を行うことができないため、空燃比が目標値からずれる虞がある。これに対し、空燃比を推定することで、空燃比が目標値からずれることを抑制できる。空燃比の推定は、例えば、空気量と燃料量とを推定することにより行うことができる。 Here, some air-fuel ratio detection devices cannot detect the air-fuel ratio until the element is activated. In a state where the air-fuel ratio cannot be detected, for example, feedback control cannot be performed, so that the air-fuel ratio may deviate from the target value. In contrast, by estimating the air-fuel ratio, it is possible to suppress the air-fuel ratio from deviating from the target value. The air-fuel ratio can be estimated, for example, by estimating the air amount and the fuel amount.
　また、本発明においては、前記排気浄化触媒の温度を検出する温度検出装置を備え、
　前記空燃比制御装置は、前記温度検出装置により検出される温度が、前記排気浄化触媒の活性温度以上であるときに、前記混合気中の前記空気と前記燃料との比である空燃比を理論空燃比よりもリッチ側とし、且つ、前記混合気中の燃料の割合を、煤の発生量が最大となるときの割合よりも大きくすることができる。 In the present invention, a temperature detection device for detecting the temperature of the exhaust purification catalyst,
The air-fuel ratio control device theoretically calculates an air-fuel ratio that is a ratio of the air and the fuel in the air-fuel mixture when the temperature detected by the temperature detection device is equal to or higher than the activation temperature of the exhaust purification catalyst. It is possible to make the fuel richer than the air-fuel ratio and to make the ratio of the fuel in the air-fuel mixture larger than the ratio when the generation amount of soot is maximized.
　すなわち、前記燃料の割合を大きくすることで、触媒にて反応しやすい燃料を供給することができるが、触媒の温度が活性温度に達していなければ該燃料を反応させることが困難となる。これに対し、触媒の温度が活性温度以上のときに燃料の割合を大きくすることで、触媒に到達した未燃燃料を反応させることができるため、該未燃燃料が触媒に堆積することを抑制できる。また、未燃燃料が触媒をすり抜けることも抑制できる。なお、温度検出装置により検出される温度が、活性温度未満の場合には、混合気の空燃比がリーン空燃比となるように空気の量及び燃料の量を調整してもよい。これにより、排気浄化触媒へ未燃燃料が流入することを抑制できる。 That is, by increasing the ratio of the fuel, it is possible to supply a fuel that easily reacts with the catalyst. However, if the temperature of the catalyst does not reach the activation temperature, it becomes difficult to react the fuel. In contrast, by increasing the fuel ratio when the catalyst temperature is equal to or higher than the activation temperature, the unburned fuel that has reached the catalyst can be reacted, so that the unburned fuel is prevented from accumulating on the catalyst. it can. It is also possible to prevent unburned fuel from passing through the catalyst. When the temperature detected by the temperature detection device is lower than the activation temperature, the amount of air and the amount of fuel may be adjusted so that the air-fuel ratio of the air-fuel mixture becomes the lean air-fuel ratio. Thereby, it can suppress that unburned fuel flows in into an exhaust gas purification catalyst.
　また、本発明においては、前記空燃比制御装置は、燃焼温度が２００℃以上で１５００℃以下となるように、且つ、空燃比が１．５以上で理論空燃比未満となるように混合気を生成させることができる。このような状態で燃料を燃焼させることにより、上記効果をより高めることができる。 In the present invention, the air-fuel ratio control device controls the air-fuel mixture so that the combustion temperature is 200 ° C. or higher and 1500 ° C. or lower, and the air-fuel ratio is 1.5 or higher and less than the stoichiometric air-fuel ratio. Can be generated. By burning the fuel in such a state, the above effect can be further enhanced.
　本発明によれば、昇温装置におけるＮＯx及びスモークの発生量を低減することができる。 According to the present invention, the amount of NOx and smoke generated in the temperature raising device can be reduced.
実施例に係る内燃機関の排気浄化装置の概略構成を示す図である。It is a figure which shows schematic structure of the exhaust gas purification apparatus of the internal combustion engine which concerns on an Example. 昇温装置の拡大断面図である。It is an expanded sectional view of a temperature rising device. 昇温装置における燃焼温度と空燃比との関係を示した図である。It is the figure which showed the relationship between the combustion temperature and air fuel ratio in a temperature rising apparatus. 燃焼室内の空燃比と燃焼温度の平均値（平均温度）との関係を示した図である。It is the figure which showed the relationship between the air fuel ratio in a combustion chamber, and the average value (average temperature) of combustion temperature. 燃焼室内の空燃比とスモーク濃度との関係を示した図である。It is the figure which showed the relationship between the air fuel ratio in a combustion chamber, and smoke concentration. 実施例に係る昇温装置の制御フローを示したフローチャートである。It is the flowchart which showed the control flow of the temperature rising apparatus which concerns on an Example. 燃焼室を排気通路の外部に設置した昇温装置の断面図である。It is sectional drawing of the temperature raising apparatus which installed the combustion chamber outside the exhaust passage. 実施例に係る混合器を備えた内燃機関の排気浄化装置の概略構成を示す図である。It is a figure which shows schematic structure of the exhaust gas purification apparatus of the internal combustion engine provided with the mixer which concerns on an Example.
　以下、本発明に係る内燃機関の排気浄化装置の具体的な実施態様について図面に基づいて説明する。 Hereinafter, specific embodiments of the exhaust gas purification apparatus for an internal combustion engine according to the present invention will be described with reference to the drawings.
　＜実施例１＞
　図１は、本実施例に係る内燃機関の排気浄化装置の概略構成を示す図である。図１に示す内燃機関１は、ディーゼル機関であっても、また、ガソリン機関であってもよい。 <Example 1>
FIG. 1 is a diagram showing a schematic configuration of an exhaust gas purification apparatus for an internal combustion engine according to the present embodiment. The internal combustion engine 1 shown in FIG. 1 may be a diesel engine or a gasoline engine.
　内燃機関１には、排気通路２が接続されている。排気通路２の途中には、排気浄化触媒３（以下、単に「触媒３」という。）が設けられている。触媒３は、たとえば、吸蔵還元型ＮＯx触媒、選択還元型ＮＯx触媒、三元触媒、酸化触媒などを例示できる。触媒３は、酸化機能を有する触媒としてもよい。また、粒子状物質を捕集するパティキュレートフィルタを備え、該パティキュレートフィルタを触媒３の担体としてもよい。また、パティキュレートフィルタよりも上流に触媒３を配置してもよい。 The exhaust passage 2 is connected to the internal combustion engine 1. An exhaust purification catalyst 3 (hereinafter simply referred to as “catalyst 3”) is provided in the middle of the exhaust passage 2. Examples of the catalyst 3 include an occlusion reduction type NOx catalyst, a selective reduction type NOx catalyst, a three-way catalyst, and an oxidation catalyst. The catalyst 3 may be a catalyst having an oxidation function. Further, a particulate filter that collects particulate matter may be provided, and the particulate filter may be used as the carrier of the catalyst 3. Moreover, you may arrange | position the catalyst 3 upstream from a particulate filter.
　また、触媒３よりも上流側の排気通路２には、昇温装置４が備えられている。この昇温装置４は、排気通路２内に設けられる燃焼室４１、燃焼室４１へ空気を供給するための空気供給管４２、空気を吐出するポンプ４３、燃焼室４１内へ燃料を噴射する噴射弁４４、燃料と空気との混合気に着火する着火装置４５を備えて構成されている。なお、本実施例においては空気供給管４２及びポンプ４３が、本発明における空気供給装置に相当する。また、本実施例においては噴射弁４４が、本発明における燃料噴射弁に相当する。 Further, a temperature raising device 4 is provided in the exhaust passage 2 upstream of the catalyst 3. The temperature raising device 4 includes a combustion chamber 41 provided in the exhaust passage 2, an air supply pipe 42 for supplying air to the combustion chamber 41, a pump 43 for discharging air, and an injection for injecting fuel into the combustion chamber 41. The valve 44 includes an ignition device 45 that ignites an air-fuel mixture of fuel and air. In this embodiment, the air supply pipe 42 and the pump 43 correspond to the air supply device in the present invention. In the present embodiment, the injection valve 44 corresponds to the fuel injection valve in the present invention.
　ここで、図２は、昇温装置４の拡大断面図である。燃焼室４１は、排気通路２の内径よりも小さな外径となるように、且つ、排気通路２の中心軸と同軸の筒状となるように形成されている。そして、燃焼室４１は、排気の流れの上流側で閉塞しており、下流側の開口部４１１で開口している。また、燃焼室４１の下流側端部には、下流側ほど直径が小さくなる絞り部４１２が備わる。 Here, FIG. 2 is an enlarged sectional view of the temperature raising device 4. The combustion chamber 41 is formed so as to have an outer diameter smaller than the inner diameter of the exhaust passage 2 and a cylindrical shape coaxial with the central axis of the exhaust passage 2. The combustion chamber 41 is closed on the upstream side of the exhaust flow, and is opened at the opening 411 on the downstream side. In addition, a downstream end portion of the combustion chamber 41 is provided with a throttle portion 412 having a diameter that decreases toward the downstream side.
　燃焼室４１には、空気供給管４２を介してポンプ４３が接続されている。ポンプ４３はたとえば電動モータを備えて構成され、その回転数に応じた空気を吐出する。そして、ポンプ４３が作動して空気を吐出することにより、燃焼室４１へ空気が供給される。なお、ポンプ４３は、内燃機関１のクランクシャフトから駆動力を得てもよい。また、ポンプ４３は、回転数を制御することで空気の吐出量を制御するものであってもよく、作動する時間と停止する時間とを調整することにより空気の吐出量を制御するものであってもよい。 A pump 43 is connected to the combustion chamber 41 via an air supply pipe 42. The pump 43 includes an electric motor, for example, and discharges air according to the number of rotations. Air is supplied to the combustion chamber 41 by operating the pump 43 to discharge air. The pump 43 may obtain driving force from the crankshaft of the internal combustion engine 1. Further, the pump 43 may control the amount of air discharged by controlling the number of rotations, and controls the amount of air discharged by adjusting the operation time and the stop time. May be.
　なお、本実施例においてはポンプ４３から空気を吐出しているが、これに代えて、内燃機関１の排気（ＥＧＲガス）を吐出してもよい。このＥＧＲガスと空気とを混合して吐出してもよい。また、空気に二酸化炭素を加えたガスを吐出してもよい。これらは、燃料の酸化を抑制するガスであり、これらのガスを供給することで後述する低温燃焼領域を拡大することができる。 In this embodiment, air is discharged from the pump 43, but instead of this, the exhaust gas (EGR gas) of the internal combustion engine 1 may be discharged. The EGR gas and air may be mixed and discharged. Alternatively, a gas obtained by adding carbon dioxide to air may be discharged. These are gases that suppress the oxidation of the fuel, and by supplying these gases, the low-temperature combustion region described later can be expanded.
　空気供給管４２には、該空気供給管４２内の圧力を検出する圧力センサ１１が設けられている。 The air supply pipe 42 is provided with a pressure sensor 11 that detects the pressure in the air supply pipe 42.
　また、燃焼室４１において、噴射弁４４から噴射された燃料４７が到達する範囲に着火装置４５が取り付けられている。着火装置４５には、たとえばグロープラグまたはスパークプラグを用いることができる。噴射弁４４は、たとえば軽油、ガソリン、合成油、プロパンガス、または水素などの可燃剤を噴射する。 In the combustion chamber 41, an ignition device 45 is attached in a range where the fuel 47 injected from the injection valve 44 reaches. For the ignition device 45, for example, a glow plug or a spark plug can be used. The injection valve 44 injects a combustible agent such as light oil, gasoline, synthetic oil, propane gas, or hydrogen.
　昇温装置４よりも下流で且つ触媒３よりも上流の排気通路２には、該排気通路２内の温度を検出する上流側温度センサ１２が取り付けられている。また、触媒３よりも下流の排気通路２には、該排気通路２内の温度を検出する下流側温度センサ１３が取り付けられている。 An upstream temperature sensor 12 for detecting the temperature in the exhaust passage 2 is attached to the exhaust passage 2 downstream from the temperature raising device 4 and upstream from the catalyst 3. A downstream temperature sensor 13 for detecting the temperature in the exhaust passage 2 is attached to the exhaust passage 2 downstream of the catalyst 3.
　以上述べたように構成された内燃機関１には、該内燃機関１を制御するための電子制御ユニットであるＥＣＵ１０が併設されている。このＥＣＵ１０は、内燃機関１の運転条件や運転者の要求に応じて内燃機関１を制御する。 The internal combustion engine 1 configured as described above is provided with an ECU 10 that is an electronic control unit for controlling the internal combustion engine 1. The ECU 10 controls the internal combustion engine 1 in accordance with the operating conditions of the internal combustion engine 1 and the driver's request.
　ＥＣＵ１０には、上記センサが電気配線を介して接続され、該センサの出力信号が入力されるようになっている。一方、ＥＣＵ１０には、ポンプ４３、噴射弁４４、着火装置４５が電気配線を介して接続され、これらはＥＣＵ１０により制御される。 The ECU 10 is connected to the sensor via electrical wiring, and an output signal of the sensor is input. On the other hand, a pump 43, an injection valve 44, and an ignition device 45 are connected to the ECU 10 via electric wiring, and these are controlled by the ECU 10.
　例えばＥＣＵ１０は、ポンプ４３、着火装置４５を作動させつつ噴射弁４４から燃料を噴射させることで昇温装置４を作動させる。これより、空気と燃料との混合気に着火して火炎４８を発生させる。 For example, the ECU 10 operates the temperature raising device 4 by injecting fuel from the injection valve 44 while operating the pump 43 and the ignition device 45. Thus, the flame 48 is generated by igniting the air-fuel mixture.
　そして、ＥＣＵ１０は、昇温装置４を作動させるときには、燃焼室４１へ供給する燃料量及び空気量を調整することにより、燃焼室４１内の空燃比及び燃焼温度を制御する。そして、ＥＣＵ１０は、燃焼室４１内において低温燃焼を行う。この低温燃焼は、リッチ空燃比であって、煤の発生量が最大となる空燃比よりも燃料の割合を大きくした空燃比での燃焼である。 The ECU 10 controls the air-fuel ratio and the combustion temperature in the combustion chamber 41 by adjusting the amount of fuel and air supplied to the combustion chamber 41 when the temperature raising device 4 is operated. The ECU 10 performs low temperature combustion in the combustion chamber 41. This low-temperature combustion is combustion at an air-fuel ratio that is a rich air-fuel ratio and has a fuel ratio larger than the air-fuel ratio at which the amount of soot is maximized.
　ここで、図３は、昇温装置４における燃焼温度と空燃比との関係を示した図である。縦軸が空燃比であり、横軸は燃焼温度である。図３において、「ＳＯＯＴ」と記載されている領域は、他の領域に比べて煤が比較的多く発生する領域である。また、「ＮＯx」と記載されている領域は、他の領域に比べてＮＯxが比較的多く発生する領域である。そして、一点鎖線よりも空燃比が大きいか又は燃焼温度が低い領域は、昇温装置４を作動させる領域である。この昇温装置４を作動させる領域であって、空燃比が破線で示される理論空燃比よりも低い領域が低温燃焼を行う領域である。なお、再生と記載されている領域は、パティキュレートフィルタに捕集されているＰＭを酸化させるときに昇温装置４を作動させる領域である。 Here, FIG. 3 is a diagram showing the relationship between the combustion temperature and the air-fuel ratio in the temperature raising device 4. The vertical axis is the air-fuel ratio, and the horizontal axis is the combustion temperature. In FIG. 3, an area described as “SOOT” is an area where wrinkles are generated relatively more than other areas. In addition, the region described as “NOx” is a region where a relatively large amount of NOx is generated as compared with other regions. And the area | region where an air fuel ratio is larger than a dashed-dotted line or combustion temperature is low is an area | region which operates the temperature rising apparatus 4. FIG. A region where the temperature raising device 4 is operated, and a region where the air-fuel ratio is lower than the stoichiometric air-fuel ratio indicated by a broken line is a region where low-temperature combustion is performed. In addition, the area | region described as reproduction | regeneration is an area | region which operates the temperature rising apparatus 4 when oxidizing PM collected by the particulate filter.
　好ましくは、空燃比が１．５から３２までの間の値となり、且つ、燃焼温度が２００℃から１５００℃までの間の値となるように、ポンプ４３及び噴射弁４４を制御する。そうすると、燃焼温度が低いためにＮＯxの生成を抑制することができる。また、燃焼温度が低いために触媒３の温度が過度に上昇することを抑制できる。さらに、低温燃焼を行うと、未燃燃料が多く排出されるが、この未燃燃料は軽質の燃料に改質されている。このように燃料を改質することで、触媒３での燃料の反応を促進することができるので、触媒３の温度上昇が容易になる。また、低温燃焼を行ったときに排出される未燃燃料は反応性が高いために、触媒３に燃料が付着することを抑制できる。 Preferably, the pump 43 and the injection valve 44 are controlled so that the air-fuel ratio becomes a value between 1.5 and 32 and the combustion temperature becomes a value between 200 ° C. and 1500 ° C. Then, since the combustion temperature is low, the generation of NOx can be suppressed. Moreover, since the combustion temperature is low, it can suppress that the temperature of the catalyst 3 rises excessively. Furthermore, when low-temperature combustion is performed, a large amount of unburned fuel is discharged, but this unburned fuel is reformed into a light fuel. By reforming the fuel in this way, the reaction of the fuel in the catalyst 3 can be promoted, so that the temperature of the catalyst 3 can be easily increased. Moreover, since the unburned fuel discharged when performing low temperature combustion has high reactivity, it can suppress that a fuel adheres to the catalyst 3. FIG.
　ここで、図４は、燃焼室４１内の空燃比と燃焼温度の平均値（平均温度）との関係を示した図である。図４中の１０ｇ／ｓ，１５ｇ／ｓ，２０ｇ／ｓ，２５ｇ／ｓ，３０ｇ／ｓは、それぞれ、空気の量を示している。このように、空燃比が同じであっても、空気量によって燃焼温度が変化することが分かる。また、空気の量に応じて燃料の量を制御することで、空燃比を一定に維持することができる。したがって、空気量及び燃料量を調整することにより、たとえば空燃比を変えずに燃焼温度を変えることができる。 Here, FIG. 4 is a diagram showing the relationship between the air-fuel ratio in the combustion chamber 41 and the average value (average temperature) of the combustion temperature. In FIG. 4, 10 g / s, 15 g / s, 20 g / s, 25 g / s, and 30 g / s indicate the amounts of air, respectively. Thus, it can be seen that the combustion temperature varies with the amount of air even if the air-fuel ratio is the same. Further, the air-fuel ratio can be kept constant by controlling the amount of fuel in accordance with the amount of air. Therefore, by adjusting the air amount and the fuel amount, for example, the combustion temperature can be changed without changing the air-fuel ratio.
　また、図５は、燃焼室４１内の空燃比とスモーク濃度との関係を示した図である。図５中の１０Ｌ／ｍｉｎ，１５Ｌ／ｍｉｎ，２０Ｌ／ｍｉｎ，２５Ｌ／ｍｉｎ，３５Ｌ／ｍｉｎ，４５Ｌ／ｍｉｎ，５０Ｌ／ｍｉｎは、それぞれ、空気の量を示している。 FIG. 5 is a diagram showing the relationship between the air-fuel ratio in the combustion chamber 41 and the smoke concentration. In FIG. 5, 10 L / min, 15 L / min, 20 L / min, 25 L / min, 35 L / min, 45 L / min, and 50 L / min indicate the amounts of air, respectively.
　たとえば、空気の量が同じ場合には、空燃比によってスモーク濃度が変化することが分かる。さらに、スモーク濃度には極大値が存在することが分かる。このように、スモーク濃度が極大値となる空燃比よりも低い空燃比となるように空気量及び燃料量を調整することで、低温燃焼を行うことができる。 For example, when the amount of air is the same, it can be seen that the smoke concentration changes depending on the air-fuel ratio. Furthermore, it can be seen that there is a maximum value in the smoke concentration. Thus, low-temperature combustion can be performed by adjusting the air amount and the fuel amount so that the air-fuel ratio becomes lower than the air-fuel ratio at which the smoke concentration becomes the maximum value.
　なお、上記低温燃焼は、触媒３の温度が活性化温度以上のときに行うようにしてもよい。この活性化温度とは、低温燃焼により排出される未燃燃料を酸化可能な温度とすることができる。触媒３が活性化したか否かは、たとえば上流側温度センサ１２または下流側温度センサ１３により判断することができる。また、触媒３の他に触媒を備えている場合には、該触媒の温度に基づいて触媒３の温度が活性化温度以上であるか否か判定してもよい。また、内燃機関１の運転状態に基づいて触媒３の温度を推定することもできる。例えば、機関回転数、アクセル開度、燃料噴射量、推定トルク、などに基づいて触媒３の温度を推定することができる。これらの関係は、予め実験等により求めてマップ化しておいてもよい。また、周知の技術を用いて触媒３の温度を推定することもできる。なお、本実施例においては触媒３の温度を推定するＥＣＵ１０、または下流側温度センサ１３が、本発明における温度検出装置に相当する。 Note that the low-temperature combustion may be performed when the temperature of the catalyst 3 is equal to or higher than the activation temperature. The activation temperature can be a temperature at which unburned fuel discharged by low temperature combustion can be oxidized. Whether or not the catalyst 3 has been activated can be determined by, for example, the upstream temperature sensor 12 or the downstream temperature sensor 13. When a catalyst is provided in addition to the catalyst 3, it may be determined whether or not the temperature of the catalyst 3 is equal to or higher than the activation temperature based on the temperature of the catalyst. Further, the temperature of the catalyst 3 can be estimated based on the operating state of the internal combustion engine 1. For example, the temperature of the catalyst 3 can be estimated based on the engine speed, the accelerator opening, the fuel injection amount, the estimated torque, and the like. These relationships may be obtained in advance through experiments or the like and mapped. Moreover, the temperature of the catalyst 3 can also be estimated using a known technique. In this embodiment, the ECU 10 that estimates the temperature of the catalyst 3 or the downstream temperature sensor 13 corresponds to the temperature detection device in the present invention.
　このように、触媒３の温度が活性温度以上のときに低温燃焼を行うことにより、未燃燃料が触媒３をすり抜けることを抑制できる。また、未燃燃料が触媒３に吸着して該触媒３の浄化能力が低下することを抑制できる。さらに、触媒３に吸着した未燃燃料が一斉に酸化されて該触媒３の温度が過度に上昇することを抑制できる。 Thus, by performing low temperature combustion when the temperature of the catalyst 3 is equal to or higher than the activation temperature, it is possible to suppress the unburned fuel from passing through the catalyst 3. Moreover, it can suppress that unburned fuel adsorb | sucks to the catalyst 3, and the purification capacity of this catalyst 3 falls. Furthermore, it can suppress that the unburned fuel adsorbed to the catalyst 3 is oxidized all at once and the temperature of the catalyst 3 rises excessively.
　また、本実施例では、燃焼室４１内に空燃比センサ４６を備えている。この空燃比センサ４６により燃焼室４１内の空燃比を検出することができる。そして、たとえば、検出される空燃比が目標値となるように、噴射弁４４からの燃料噴射量またはポンプ４３から吐出する空気量の少なくとも一方のフィードバック制御を行う。なお、本実施例においては空燃比センサ４６が、本発明における空燃比検出装置に相当する。 In this embodiment, an air-fuel ratio sensor 46 is provided in the combustion chamber 41. The air-fuel ratio sensor 46 can detect the air-fuel ratio in the combustion chamber 41. Then, for example, feedback control of at least one of the fuel injection amount from the injection valve 44 or the air amount discharged from the pump 43 is performed so that the detected air-fuel ratio becomes the target value. In this embodiment, the air-fuel ratio sensor 46 corresponds to the air-fuel ratio detection device in the present invention.
　空燃比センサ４６は、燃焼室４１の下流端近傍、すなわち燃焼室４１の開口部４１１近傍で、且つ内燃機関１の排気の影響を受け難い箇所に取り付けられる。内燃機関１の排気の影響を受け難い箇所とは、たとえば、内燃機関１からの排気が流通しない箇所である。また、混合気の空燃比を正確に検出する必要があるため、空燃比センサ４６は混合気が流通する箇所に取り付けられる。また、開口部４１１に近付け過ぎると、空燃比センサ４６の温度が過度に高くなり、空燃比センサ４６が劣化する虞がある。これらを考慮して、本実施例では、噴射弁４４よりも下流側で且つ絞り部４１２よりも上流側に空燃比センサ４６を取り付けている。なお、空燃比センサ４６を取り付ける最適な位置は、実験等により求めてもよい。 The air-fuel ratio sensor 46 is attached in the vicinity of the downstream end of the combustion chamber 41, that is, in the vicinity of the opening 411 of the combustion chamber 41 and at a location that is not easily affected by the exhaust gas of the internal combustion engine 1. The part that is hardly affected by the exhaust of the internal combustion engine 1 is a part where the exhaust from the internal combustion engine 1 does not circulate, for example. Further, since it is necessary to accurately detect the air-fuel ratio of the air-fuel mixture, the air-fuel ratio sensor 46 is attached to a location where the air-fuel mixture flows. Further, if the distance is too close to the opening 411, the temperature of the air-fuel ratio sensor 46 becomes excessively high and the air-fuel ratio sensor 46 may be deteriorated. In consideration of these points, in this embodiment, the air-fuel ratio sensor 46 is attached downstream of the injection valve 44 and upstream of the throttle portion 412. The optimum position for attaching the air-fuel ratio sensor 46 may be obtained by experiments or the like.
　このように空燃比センサ４６を燃焼室４１内に設置することで、燃焼室４１内の空燃比をより精密に制御することができる。そうすると、スモークやＮＯxの生成量をより減少させることができる。また、ポンプ４３や噴射弁４４の個体差や経年変化により、空気量または燃料噴射量に誤差が生じた場合であっても、これらを補正することができる。さらに、空燃比センサ４６を燃焼室４１内に設置することで、高温の燃焼ガスが空燃比センサ４６に当たり難くなるので、空燃比センサ４６の劣化を抑制できる。さらに、空燃比センサ４６の検出値に基づいて、昇温装置４の故障検出を行うこともできる。 By thus installing the air-fuel ratio sensor 46 in the combustion chamber 41, the air-fuel ratio in the combustion chamber 41 can be controlled more precisely. As a result, the amount of smoke and NOx produced can be further reduced. Further, even when an error occurs in the air amount or the fuel injection amount due to individual differences or aging of the pump 43 or the injection valve 44, these can be corrected. Furthermore, by installing the air-fuel ratio sensor 46 in the combustion chamber 41, it becomes difficult for high-temperature combustion gas to hit the air-fuel ratio sensor 46, so that deterioration of the air-fuel ratio sensor 46 can be suppressed. Further, failure detection of the temperature raising device 4 can be performed based on the detection value of the air-fuel ratio sensor 46.
　ところで、空燃比センサ４６は、素子を活性化させるためのヒータを内蔵している。このヒータにより素子の温度を上昇させるときに電力が供給される。本実施例では、燃焼室４１内に空燃比センサ４６を設置することで、燃焼により発生した熱が空燃比センサ６に供給される。このため、空燃比センサ４６の素子の温度を上昇させるための電力を低減させることができる。これにより、燃費を向上させることができる。 Incidentally, the air-fuel ratio sensor 46 incorporates a heater for activating the element. Electric power is supplied when the temperature of the element is raised by this heater. In this embodiment, the air-fuel ratio sensor 46 is installed in the combustion chamber 41 so that heat generated by the combustion is supplied to the air-fuel ratio sensor 6. For this reason, the electric power for raising the temperature of the element of the air-fuel ratio sensor 46 can be reduced. Thereby, fuel consumption can be improved.
　さらに、燃焼室４１内は排気の流れの下流側に向けて開口しているため、排気通路２内で発生する凝縮水が燃焼室４１に入り難い。このため、空燃比センサ４６に凝縮水が付着することを抑制できる。これにより、空燃比センサ４６が劣化することを抑制できる。 Furthermore, since the inside of the combustion chamber 41 opens toward the downstream side of the exhaust flow, the condensed water generated in the exhaust passage 2 is difficult to enter the combustion chamber 41. For this reason, it is possible to prevent the condensed water from adhering to the air-fuel ratio sensor 46. Thereby, it can suppress that the air fuel ratio sensor 46 deteriorates.
　なお、空燃比センサ４６は、混合気の空燃比の値を検出するものであるが、これに代えて、理論空燃比を境に出力値が変化するものであってもよい。 The air-fuel ratio sensor 46 detects the value of the air-fuel ratio of the air-fuel mixture. Alternatively, the output value may change with the stoichiometric air-fuel ratio as a boundary.
　また、空燃比センサ４６の素子が活性化するまでは、空燃比を検出することが困難となる。したがって、素子が活性化して、空燃比センサ４６にて空燃比を検出可能となった後に、昇温装置４を作動させてもよい。 In addition, it becomes difficult to detect the air-fuel ratio until the element of the air-fuel ratio sensor 46 is activated. Therefore, the temperature raising device 4 may be operated after the element is activated and the air-fuel ratio sensor 46 can detect the air-fuel ratio.
　また、空燃比センサ４６にて空燃比を検出することができない間は、燃焼室４１内の空燃比を推定してもよい。そして、空燃比の推定値に基づいて、空気量または燃料噴射量を制御してもよい。空燃比を推定するために、たとえば、空気量と燃料噴射量とを推定する。空気量は、たとえば、ポンプ４３の回転数、空気供給管４２内の圧力、空気供給管４２内の温度、ポンプ４３に流入する空気の流量、または、ポンプ４３から流出する空気の流量などに基づいて推定することができる。これらの値は、センサを取り付けることにより検出することができる。そして、たとえば、これらの値と空気量との関係をマップ化してＥＣＵ１０に記憶しておけば、該マップに基づいて空気量を推定することができる。また、空気量の算出式をＥＣＵ１０に記憶しておき、該算出式に基づいて空気量を推定してもよい。また、空気量の推定は、周知の技術を用いることもできる。 Further, the air-fuel ratio in the combustion chamber 41 may be estimated while the air-fuel ratio sensor 46 cannot detect the air-fuel ratio. Then, the air amount or the fuel injection amount may be controlled based on the estimated value of the air-fuel ratio. In order to estimate the air-fuel ratio, for example, an air amount and a fuel injection amount are estimated. The amount of air is based on, for example, the number of rotations of the pump 43, the pressure in the air supply pipe 42, the temperature in the air supply pipe 42, the flow rate of air flowing into the pump 43, or the flow rate of air flowing out of the pump 43. Can be estimated. These values can be detected by attaching a sensor. For example, if the relationship between these values and the air amount is mapped and stored in the ECU 10, the air amount can be estimated based on the map. Moreover, the calculation formula of air quantity may be memorize | stored in ECU10, and air quantity may be estimated based on this calculation formula. A known technique can also be used for estimating the air amount.
　一方、燃料噴射量は、噴射弁４４の開弁時間、燃料の流量、燃料の圧力などに基づいて推定することができる。噴射弁４４の開弁時間はＥＣＵ１０で算出される指令値から得てもよい。また、燃料の流量及び燃料の圧力は、センサを設置することにより検出することができる。そして、たとえば、これらの値と燃料噴射量との関係をマップ化してＥＣＵ１０に記憶しておけば、該マップに基づいて燃料噴射量を推定することができる。また、燃料噴射量の算出式をＥＣＵ１０に記憶しておき、該算出式に基づいて燃料噴射量を推定してもよい。また、燃料噴射量の推定は、周知の技術を用いることもできる。 On the other hand, the fuel injection amount can be estimated based on the valve opening time of the injection valve 44, the fuel flow rate, the fuel pressure, and the like. The valve opening time of the injection valve 44 may be obtained from a command value calculated by the ECU 10. The fuel flow rate and fuel pressure can be detected by installing a sensor. For example, if the relationship between these values and the fuel injection amount is mapped and stored in the ECU 10, the fuel injection amount can be estimated based on the map. Alternatively, a calculation formula for the fuel injection amount may be stored in the ECU 10 and the fuel injection amount may be estimated based on the calculation formula. A known technique can also be used for estimating the fuel injection amount.
　このようにして推定した空気量と燃料噴射量との比を算出することで、空燃比を推定することができる。そして、空燃比センサ４６により空燃比を検出することができないときに、空燃比の推定値を用いて燃料噴射量または空気量を制御すれば、ＮＯxやスモークの発生を抑制できる。なお、本実施例では、空燃比を推定するＥＣＵ１０が、本発明における空燃比推定装置に相当する。 The air-fuel ratio can be estimated by calculating the ratio between the air amount estimated in this way and the fuel injection amount. When the air-fuel ratio cannot be detected by the air-fuel ratio sensor 46, the generation of NOx and smoke can be suppressed by controlling the fuel injection amount or the air amount using the estimated value of the air-fuel ratio. In the present embodiment, the ECU 10 that estimates the air-fuel ratio corresponds to the air-fuel ratio estimation device in the present invention.
　なお、空燃比センサ４６により空燃比を検出することができないときには、触媒３の温度も低いと考えられる。この場合、未燃燃料を浄化することが困難となる。したがって、このときには、昇温装置４においてリーン空燃比となるように空気量または燃料噴射量を調整してもよい。これにより、昇温装置４から未燃燃料が排出されることを抑制できる。 It should be noted that when the air-fuel ratio cannot be detected by the air-fuel ratio sensor 46, the temperature of the catalyst 3 is considered to be low. In this case, it becomes difficult to purify the unburned fuel. Therefore, at this time, the air amount or the fuel injection amount may be adjusted in the temperature raising device 4 so that the lean air-fuel ratio is obtained. Thereby, it can suppress that unburned fuel is discharged | emitted from the temperature rising apparatus 4. FIG.
　また、本実施例に係る昇温装置４は、触媒３の温度を上昇させるほかに、フィルタに捕集されているＰＭを酸化させる場合にも用いることができる。すなわち、触媒３にて未燃燃料を酸化させたときの熱によりＰＭを酸化させることができる。 Further, the temperature raising device 4 according to the present embodiment can be used not only for raising the temperature of the catalyst 3 but also for oxidizing the PM collected by the filter. That is, PM can be oxidized by heat generated when the unburned fuel is oxidized by the catalyst 3.
　図６は、本実施例に係る昇温装置４の制御フローを示したフローチャートである。本ルーチンは、ＥＣＵ１０により、所定の時間毎に実施される。 FIG. 6 is a flowchart showing a control flow of the temperature raising device 4 according to the present embodiment. This routine is executed by the ECU 10 every predetermined time.
　ステップＳ１０１では、触媒３が活性しているか否か判定される。たとえば、下流側温度センサ１３により触媒３の温度を検出し、該温度が、活性温度以上である場合に触媒３が活性していると判定される。本ステップでは、触媒３へ未燃燃料を供給したときに、未燃燃料が触媒３で酸化されるか否か判定している。 In step S101, it is determined whether the catalyst 3 is active. For example, the temperature of the catalyst 3 is detected by the downstream temperature sensor 13, and when the temperature is equal to or higher than the activation temperature, it is determined that the catalyst 3 is active. In this step, it is determined whether the unburned fuel is oxidized by the catalyst 3 when the unburned fuel is supplied to the catalyst 3.
　ステップＳ１０１で肯定判定がなされた場合にはステップＳ１０４へ進み、一方、否定判定がなされた場合にはステップＳ１０２へ進む。 If an affirmative determination is made in step S101, the process proceeds to step S104. On the other hand, if a negative determination is made, the process proceeds to step S102.
　ステップＳ１０２では、目標空燃比をリーン空燃比として昇温装置４を作動させる。すなわち、触媒３が活性していないために未燃燃料を酸化させることができないので、未燃燃料が触媒３へ到達しないようにしつつ該触媒３の温度を上昇させる。このときの空燃比は、たとえば３２以下とする。また、燃焼温度を例えば２００℃以上で且つ１５００℃以下とする。これにより、ＮＯxの発生を抑制することができる。 In step S102, the temperature raising device 4 is operated with the target air-fuel ratio as the lean air-fuel ratio. That is, since the unburned fuel cannot be oxidized because the catalyst 3 is not activated, the temperature of the catalyst 3 is raised while preventing the unburned fuel from reaching the catalyst 3. The air-fuel ratio at this time is set to 32 or less, for example. Further, the combustion temperature is, for example, 200 ° C. or more and 1500 ° C. or less. Thereby, generation | occurrence | production of NOx can be suppressed.
　ステップＳ１０３では、触媒３が活性しているか否か判定される。本ステップでは、ステップＳ１０１と同じ処理がなされる。ステップＳ１０３で肯定判定がなされた場合にはステップＳ１０４へ進み、否定判定がなされた場合にはステップＳ１０２へ戻る。 In step S103, it is determined whether or not the catalyst 3 is active. In this step, the same processing as in step S101 is performed. If an affirmative determination is made in step S103, the process proceeds to step S104, and if a negative determination is made, the process returns to step S102.
　ステップＳ１０４では、昇温装置４で低温燃焼を行う。これにより、軽質となった未燃燃料を触媒３へ供給することができる。そうすると、触媒３の温度をさらに上昇させることができる。また、パティキュレートフィルタを備えている場合には、触媒３の温度を上昇させることにより、パティキュレートフィルタからＰＭを除去することもできる。なお、本実施例ではステップＳ１０４を処理するＥＣＵ１０が、本発明における空燃比制御装置に相当する。 In step S104, the temperature raising device 4 performs low temperature combustion. Thereby, the unburned fuel which became light can be supplied to the catalyst 3. As a result, the temperature of the catalyst 3 can be further increased. In addition, when a particulate filter is provided, PM can be removed from the particulate filter by increasing the temperature of the catalyst 3. In the present embodiment, the ECU 10 that processes step S104 corresponds to the air-fuel ratio control apparatus according to the present invention.
　なお、本実施例では、燃焼室４１を排気通路２の内部に設置しているが、これに代えて、燃焼室４１を排気通路２の外部に設置してもよい。そして、燃焼室４１の出口を排気通路２に接続してもよい。 In this embodiment, the combustion chamber 41 is installed inside the exhaust passage 2, but instead, the combustion chamber 41 may be installed outside the exhaust passage 2. Then, the outlet of the combustion chamber 41 may be connected to the exhaust passage 2.
　図７は、燃焼室４０１を排気通路２の外部に設置した昇温装置４００の断面図である。図２に示した昇温装置４と同じ部材については同じ符号を付して説明を省略する。図７に示す昇温装置４００は、燃焼室４０１に開口部４０２を設けてあり、該開口部４０２に併せて排気通路２にも孔２１が設けられている。燃焼室４０１内には、開口部４０２側から順に、空燃比センサ４６、着火装置４５、噴射弁４４、空気供給管４２が取り付けられている。このような構成であっても、低温燃焼を行うことができる。 FIG. 7 is a cross-sectional view of the temperature raising device 400 in which the combustion chamber 401 is installed outside the exhaust passage 2. The same members as those of the temperature raising device 4 shown in FIG. In the temperature raising device 400 shown in FIG. 7, an opening 402 is provided in the combustion chamber 401, and a hole 21 is also provided in the exhaust passage 2 along with the opening 402. In the combustion chamber 401, an air-fuel ratio sensor 46, an ignition device 45, an injection valve 44, and an air supply pipe 42 are attached in this order from the opening 402 side. Even with such a configuration, low-temperature combustion can be performed.
　また、昇温装置４よりも上流側または下流側に排気を撹拌するための混合器５を備えていてもよい。 Further, a mixer 5 for stirring the exhaust gas may be provided upstream or downstream of the temperature raising device 4.
　図８は、本実施例に係る混合器５を備えた内燃機関の排気浄化装置の概略構成を示す図である。図１に示した内燃機関の排気浄化装置と比較して、燃焼室４１よりも下流で且つ上流側温度センサ１２よりも上流に混合器５を取り付けている点が異なる。この混合器５は、例えば排気の流れの方向を変える複数の板を備えて構成される。このような混合器５を備えることで、排気中の未燃燃料を均一に分散させることができる。また、排気の温度を均一にすることができる。なお、混合器５は、燃焼室４１よりも上流に備えていてもよい。 FIG. 8 is a diagram showing a schematic configuration of an exhaust gas purification apparatus for an internal combustion engine provided with the mixer 5 according to the present embodiment. Compared with the exhaust gas purification apparatus for an internal combustion engine shown in FIG. 1, the difference is that the mixer 5 is attached downstream of the combustion chamber 41 and upstream of the upstream temperature sensor 12. The mixer 5 includes, for example, a plurality of plates that change the direction of the exhaust flow. By providing such a mixer 5, unburned fuel in the exhaust can be uniformly dispersed. Further, the exhaust temperature can be made uniform. The mixer 5 may be provided upstream from the combustion chamber 41.
　以上説明したように本実施例によれば、触媒３の温度を上昇させるときに昇温装置４にて低温燃焼を行うことにより、ＮＯx及びスモークの発生量を低減することができる。これにより、触媒３に流入するＰＭやＮＯxの量を低減しつつ触媒３の温度を上昇させることができる。また、重質なＨＣを軽質なＨＣに変化させることができるため、触媒３におけるＨＣの反応を促進させることができる。これにより、触媒３の温度を速やかに上昇させることができる。また、触媒３が未燃燃料により詰まることも抑制できる。また、反応性の高いＣＯを発生させることができるため、触媒３においてより多くの反応熱を得ることができるので、触媒３の温度上昇が容易となる。また、昇温装置４に供給する空気量を比較的少なくすることができるため、ポンプ４３に供給する電力を低減させることができる。 As described above, according to this embodiment, when the temperature of the catalyst 3 is raised, the temperature raising device 4 performs low temperature combustion, thereby reducing the amount of NOx and smoke generated. Thereby, the temperature of the catalyst 3 can be raised while reducing the amount of PM and NOx flowing into the catalyst 3. Moreover, since heavy HC can be changed into light HC, the reaction of HC in the catalyst 3 can be promoted. Thereby, the temperature of the catalyst 3 can be raised rapidly. It is also possible to suppress the catalyst 3 from being clogged with unburned fuel. In addition, since highly reactive CO can be generated, more heat of reaction can be obtained in the catalyst 3, so that the temperature of the catalyst 3 can be easily increased. Further, since the amount of air supplied to the temperature raising device 4 can be relatively reduced, the power supplied to the pump 43 can be reduced.
　また、燃焼室４１内に空燃比センサ４６を設置することで、空燃比を精度よく検出することができると共に、該空燃比センサ４６の劣化を抑制することができる。これにより、昇温装置４において低温燃焼をより容易に行うことができる。 In addition, by installing the air-fuel ratio sensor 46 in the combustion chamber 41, the air-fuel ratio can be detected with high accuracy, and deterioration of the air-fuel ratio sensor 46 can be suppressed. Thereby, low temperature combustion can be performed more easily in the temperature raising device 4.
１     内燃機関
２     排気通路
３     排気浄化触媒
４     昇温装置
５     混合器
１０   ＥＣＵ
１１   圧力センサ
１２   上流側温度センサ
１３   下流側温度センサ
４１   燃焼室
４２   空気供給管
４３   ポンプ
４４   噴射弁
４５   着火装置
４６   空燃比センサ
４１１ 開口部
４１２ 絞り部 DESCRIPTION OF SYMBOLS 1 Internal combustion engine 2 Exhaust passage 3 Exhaust purification catalyst 4 Temperature raising device 5 Mixer 10 ECU
11 Pressure sensor 12 Upstream temperature sensor 13 Downstream temperature sensor 41 Combustion chamber 42 Air supply pipe 43 Pump 44 Injection valve 45 Ignition device 46 Air-fuel ratio sensor 411 Opening 412 Restriction

Claims (7)

  1. 　内燃機関の排気通路に設けられる排気浄化触媒と、
    　前記排気浄化触媒よりも上流の排気通路に設けられる昇温装置と、
    　を備える内燃機関の排気浄化装置において、
    　前記昇温装置は、空気を供給する空気供給装置、燃料を供給する燃料噴射弁、前記空気と前記燃料との混合気を燃焼させる燃焼室を備えて構成され、
    　前記燃焼室において前記混合気を燃焼させるときに、前記混合気中の前記空気と前記燃料との比である空燃比を理論空燃比よりもリッチ側とし、且つ、前記混合気中の燃料の割合を、煤の発生量が最大となるときの割合よりも大きくする空燃比制御装置を備える内燃機関の排気浄化装置。     An exhaust purification catalyst provided in the exhaust passage of the internal combustion engine;
    A temperature raising device provided in an exhaust passage upstream of the exhaust purification catalyst;
    An exhaust gas purification apparatus for an internal combustion engine comprising:
    The temperature raising device includes an air supply device that supplies air, a fuel injection valve that supplies fuel, and a combustion chamber that burns an air-fuel mixture of the air and the fuel,
    When the air-fuel mixture is burned in the combustion chamber, the air-fuel ratio that is the ratio of the air and the fuel in the air-fuel mixture is made richer than the stoichiometric air-fuel ratio, and the ratio of the fuel in the air-fuel mixture An exhaust gas purification apparatus for an internal combustion engine comprising an air-fuel ratio control device that makes the ratio larger than the ratio at which the amount of soot generated becomes maximum.
  2. 　前記燃焼室内に、前記混合気の空燃比を検出する空燃比検出装置を備える請求項１に記載の内燃機関の排気浄化装置。 The exhaust gas purification device for an internal combustion engine according to claim 1, further comprising an air-fuel ratio detection device for detecting an air-fuel ratio of the air-fuel mixture in the combustion chamber.
  3. 　前記空燃比検出装置を、前記燃料噴射弁よりも該燃焼室の出口側に備える請求項２に記載の内燃機関の排気浄化装置。 3. The exhaust gas purification apparatus for an internal combustion engine according to claim 2, wherein the air-fuel ratio detection device is provided on the outlet side of the combustion chamber with respect to the fuel injection valve.
  4. 　前記空燃比検出装置を、前記混合気が通過する位置に備える請求項２または３に記載の内燃機関の排気浄化装置。 The exhaust gas purification apparatus for an internal combustion engine according to claim 2 or 3, wherein the air-fuel ratio detection device is provided at a position where the air-fuel mixture passes.
  5. 　前記空燃比検出装置により空燃比の検出を行うことができないときに前記燃焼室内の空燃比を推定する空燃比推定装置を備える請求項２から４の何れか１項に記載の内燃機関の排気浄化装置。 The exhaust purification of an internal combustion engine according to any one of claims 2 to 4, further comprising an air-fuel ratio estimation device that estimates an air-fuel ratio in the combustion chamber when the air-fuel ratio cannot be detected by the air-fuel ratio detection device. apparatus.
  6. 　前記排気浄化触媒の温度を検出する温度検出装置を備え、
    　前記空燃比制御装置は、前記温度検出装置により検出される温度が、前記排気浄化触媒の活性温度以上であるときに、前記混合気中の前記空気と前記燃料との比である空燃比を理論空燃比よりもリッチ側とし、且つ、前記混合気中の燃料の割合を、煤の発生量が最大となるときの割合よりも大きくする請求項１から５の何れか１項に記載の内燃機関の排気浄化装置。     A temperature detection device for detecting the temperature of the exhaust purification catalyst;
    The air-fuel ratio control device theoretically calculates an air-fuel ratio that is a ratio of the air and the fuel in the air-fuel mixture when the temperature detected by the temperature detection device is equal to or higher than the activation temperature of the exhaust purification catalyst. 6. The internal combustion engine according to claim 1, wherein the internal combustion engine is richer than the air-fuel ratio, and the ratio of the fuel in the mixture is larger than the ratio when the amount of soot is maximized. Exhaust purification equipment.
  7. 　前記空燃比制御装置は、燃焼温度が２００℃以上で１５００℃以下となるように、且つ、空燃比が１．５以上で理論空燃比未満となるように混合気を生成させる請求項１から６の何れか１項に記載の内燃機関の排気浄化装置。 7. The air-fuel ratio control device generates an air-fuel mixture so that a combustion temperature is 200 ° C. or more and 1500 ° C. or less, and an air-fuel ratio is 1.5 or more and less than a theoretical air-fuel ratio. The exhaust gas purification apparatus for an internal combustion engine according to any one of the above.
PCT/JP2011/062369 2011-05-30 2011-05-30 Exhaust gas purification device for internal combustion engine WO2012164661A1 (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
PCT/JP2011/062369 WO2012164661A1 (en) 2011-05-30 2011-05-30 Exhaust gas purification device for internal combustion engine

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
PCT/JP2011/062369 WO2012164661A1 (en) 2011-05-30 2011-05-30 Exhaust gas purification device for internal combustion engine

Publications (1)

Publication Number Publication Date
WO2012164661A1 true WO2012164661A1 (en) 2012-12-06

Family

ID=47258547

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/JP2011/062369 WO2012164661A1 (en) 2011-05-30 2011-05-30 Exhaust gas purification device for internal combustion engine

Country Status (1)

Country Link
WO (1) WO2012164661A1 (en)

Cited By (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2016109097A (en) * 2014-12-10 2016-06-20 日野自動車株式会社 Exhaust purification device
GB2533609A (en) * 2014-12-22 2016-06-29 Gm Global Tech Operations Llc An internal combustion engine equipped with a lean NOx trap
JP2016211479A (en) * 2015-05-12 2016-12-15 株式会社Ihi Burner device and engine system
JP2016217260A (en) * 2015-05-21 2016-12-22 株式会社Ihi Burner device and engine system
JP2018071360A (en) * 2016-10-25 2018-05-10 株式会社三五 Exhaust purification device
US20230003155A1 (en) * 2021-06-30 2023-01-05 Marelli Europe S.P.A. Method to Control a Burner for an Exhaust System of an Internal Combustion Engine

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2000186537A (en) * 1998-12-22 2000-07-04 Toyota Motor Corp Exhaust emission control device of internal combustion engine
JP2000291462A (en) * 1999-02-02 2000-10-17 Toyota Motor Corp Internal combustion engine
JP2002371874A (en) * 2001-06-12 2002-12-26 Toyota Motor Corp Internal combustion engine
JP2006057478A (en) * 2004-08-18 2006-03-02 Bosch Corp Regeneration method of exhaust emission control member and regeneration device of exhaust emission control member
JP2007032398A (en) * 2005-07-26 2007-02-08 Toyota Motor Corp Exhaust emission control device for internal combustion engine

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2000186537A (en) * 1998-12-22 2000-07-04 Toyota Motor Corp Exhaust emission control device of internal combustion engine
JP2000291462A (en) * 1999-02-02 2000-10-17 Toyota Motor Corp Internal combustion engine
JP2002371874A (en) * 2001-06-12 2002-12-26 Toyota Motor Corp Internal combustion engine
JP2006057478A (en) * 2004-08-18 2006-03-02 Bosch Corp Regeneration method of exhaust emission control member and regeneration device of exhaust emission control member
JP2007032398A (en) * 2005-07-26 2007-02-08 Toyota Motor Corp Exhaust emission control device for internal combustion engine

Cited By (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2016109097A (en) * 2014-12-10 2016-06-20 日野自動車株式会社 Exhaust purification device
GB2533609A (en) * 2014-12-22 2016-06-29 Gm Global Tech Operations Llc An internal combustion engine equipped with a lean NOx trap
JP2016211479A (en) * 2015-05-12 2016-12-15 株式会社Ihi Burner device and engine system
JP2016217260A (en) * 2015-05-21 2016-12-22 株式会社Ihi Burner device and engine system
JP2018071360A (en) * 2016-10-25 2018-05-10 株式会社三五 Exhaust purification device
US20230003155A1 (en) * 2021-06-30 2023-01-05 Marelli Europe S.P.A. Method to Control a Burner for an Exhaust System of an Internal Combustion Engine
US11649754B2 (en) * 2021-06-30 2023-05-16 Marelli Europe S.P.A. Method to control a burner for an exhaust system of an internal combustion engine

Similar Documents

Publication Publication Date Title
CN111734517B (en) Device and method for exhaust gas aftertreatment of an internal combustion engine
WO2012164661A1 (en) Exhaust gas purification device for internal combustion engine
US7490463B2 (en) Process and system for removing soot from particulate filters of vehicle exhaust systems
JP5218645B2 (en) Temperature raising system for exhaust purification catalyst
US9206724B2 (en) Exhaust gas purification system for internal combustion engine
JP2009185628A (en) Fuel injection control system for internal combustion engine
JP2013087770A (en) Soot filter regenerating system and method thereof
EP2447494B1 (en) Exhaust emission control device for internal combustion engine
JP2005214200A (en) System and method for removing hydrogen sulfide from emission stream
WO2012066606A1 (en) Exhaust gas purification device for internal combustion engine
JP2008121455A (en) Control device of internal combustion engine
JP5120503B2 (en) Internal combustion engine
US9097167B2 (en) Exhaust gas purification device of internal combustion engine
JP2010127186A (en) Exhaust emission control device of internal combustion engine
CN108571359B (en) Exhaust gas purification device for internal combustion engine
JP2009085079A (en) Catalyst deterioration detecting device of internal combustion engine
JP2005240716A (en) Deterioration diagnostic device for catalyst
CN110857645B (en) Exhaust gas purification device and exhaust gas purification method for internal combustion engine
JP2009138546A (en) Vehicle and method of controlling internal combustion engine
WO2012137247A1 (en) Internal combustion engine equipped with burner apparatus
US11028750B2 (en) Control device for internal combustion engine
WO2023127299A1 (en) Engine system
JP2010242658A (en) System for raising temperature of exhaust emission control catalyst
JP2005232975A (en) Exhaust emission control device
JP2017190725A (en) Exhaust emission control device for internal combustion engine

Legal Events

Date Code Title Description
121 Ep: the epo has been informed by wipo that ep was designated in this application

Ref document number: 11866795

Country of ref document: EP

Kind code of ref document: A1

NENP Non-entry into the national phase

Ref country code: DE

NENP Non-entry into the national phase

Ref country code: JP

122 Ep: pct application non-entry in european phase

Ref document number: 11866795

Country of ref document: EP

Kind code of ref document: A1