JP2007285157A - Internal combustion engine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an internal combustion engine enhancing the reforming performance by a reforming catalyst. <P>SOLUTION: A reformer 26 is connected via an exhaust gas branch flow pipe 28 for branching a part of an exhaust gas flowing in an exhaust pipe 25. A second injector 29 is fitted to the exhaust gas branch flow pipe 28. A reformed gas introduction pipe 60 for introducing the reformed gas generated in the reformer 26 and a flow rate regulating valve 31 are provided. An ECU 32 controls the second injector 29 so that the amount of the fuel injected by the second injector 29 is within a control range set based on the floor temperature of a reforming catalyst of the reformer 26 and the amount of the reformed gas to be introduced in an intake pipe 15 through a reformed gas introduction pipe 30. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an internal combustion engine equipped with a fuel reformer, and in particular, supplies fuel to a part of the recirculation gas of exhaust gas and then reforms it with heat to generate reformed gas. The present invention relates to an internal combustion engine supplied to a passage.

Conventionally, a part of the exhaust gas of an internal combustion engine is taken out and supplied to the intake passage as a recirculation gas, and this recirculation gas is mixed with the intake air, thereby lowering the maximum temperature during combustion and reducing NOx in the exhaust gas. There is an exhaust gas recirculation (EGR) system. Further, as an improved system of this EGR system, in recent years, a part of fuel is added to the recirculated gas, and the mixed gas in which the fuel is mixed with the exhaust gas is heated using the heat of the exhaust gas and the reforming catalyst is passed. Thus, an endothermic reforming reaction is performed on the mixed gas, a reformed gas containing hydrogen (H ₂ ) and carbon monoxide (CO) is generated from the mixed gas, and the reformer gas is supplied to the intake passage. Thus, an efficient exhaust heat recovery and fuel efficiency improvement has been proposed.

  An example of such an exhaust reformer system for an internal combustion engine is described in Patent Document 1 below. In the exhaust reformer system of the internal combustion engine described in Patent Document 1, a fuel injection valve is provided in the intake port, and another fuel injection valve, a fuel evaporator, a reforming catalyst, and a recirculation pipe branched from the exhaust pipe are provided. A reformer gas control valve is provided. Normally, the reformer gas control valve is closed and fuel is injected into the intake port to introduce the air-fuel mixture into the combustion chamber. The control valve is opened, fuel is injected into the reflux pipe, and reformer gas generated by the reforming catalyst is introduced into the combustion chamber and burned.

JP 2004-092520 A

  In the above-described conventional exhaust reformer system for an internal combustion engine, fuel is injected into the recirculation pipe, and the reformed gas is generated by the endothermic reforming reaction with the reformed catalyst using the mixed gas mixed with the exhaust gas. The generated reformed gas is introduced into the combustion chamber.

  By the way, when the bed temperature of the reforming catalyst supported on the reformer becomes a predetermined active temperature (for example, 600 ° C.) or higher, the reforming reaction of the mixed gas is promoted to generate the reformed gas. it can. However, when the internal combustion engine is started or operated at a light load, the reforming catalyst cannot be sufficiently heated by the heat of the exhaust gas, and the reforming catalyst has not risen to a predetermined activation temperature, and the reforming reaction is not performed. As a result, the generation of the reformed gas becomes insufficient. Then, a sufficient amount of reformed gas cannot be introduced into the combustion chamber, and efficient exhaust heat recovery and fuel efficiency improvement cannot be achieved.

In addition, when the internal combustion engine is started or operated at a light load, the reforming catalyst has not risen to a predetermined activation temperature, and reforming does not proceed sufficiently to hydrogen (H ₂ ) or carbon monoxide (CO). (C) is generated, and a problem referred to as coking that adheres to the reformer (reforming catalyst) occurs, resulting in a reduction in catalyst performance.

  An object of the present invention is to solve such a problem, and an object of the present invention is to provide an internal combustion engine that is improved in reforming performance by a reforming catalyst.

  In order to solve the above-described problems and achieve the object, an internal combustion engine of the present invention includes an intake passage for introducing outside air into a combustion chamber, and first fuel supply means for supplying fuel to the intake passage or the combustion chamber. The fuel is supplied to the exhaust passage for exhausting the exhaust gas discharged from the combustion chamber to the outside, the exhaust gas branch passage for part of the exhaust gas flowing through the exhaust passage, and the exhaust gas branch passage A second fuel supply unit, a reformer for generating a reformed gas by flowing in an exhaust gas flowing through the exhaust gas diversion passage to which fuel is supplied from the second fuel supply unit, and a generator generated by the reformer A reformed gas introduction passage for introducing the reformed gas into the intake passage, a fuel supply amount of the second fuel supply means, a bed temperature of the reforming catalyst carried on the reformer, and the reformed gas introduction And the amount of reformed gas introduced into the intake passage through the passage. Is characterized in that comprises a fuel supply quantity control means for controlling said second fuel supply means so as to set control area.

  In the internal combustion engine of the present invention, the control region is a region in which a ratio of the second fuel supply amount / reformed gas amount to the bed temperature of the reforming catalyst is a predetermined ratio or less. .

  In the internal combustion engine of the present invention, the control region is a region in which carbon is not generated in the reformed gas generated by the reformer.

  According to the internal combustion engine of the present invention, the second fuel supply means for supplying the fuel to the exhaust gas diversion passage for diverting a part of the exhaust gas flowing through the exhaust passage is provided, and the exhaust gas supplied with the fuel is introduced. A reformer for generating reformed gas is provided, a reformed gas introduction passage for introducing the reformed gas generated by the reformer into the intake passage is provided, and the amount of fuel supplied from the second fuel supply means is the reformer. For controlling the second fuel supply means so as to be within a control region set based on the bed temperature of the reforming catalyst carried on the catalyst and the amount of reformed gas introduced into the intake passage through the reformed gas introduction passage Since the supply amount control means is provided, the supply fuel from the second fuel supply means can be controlled to the optimum amount based on the bed temperature of the reforming catalyst and the reformed gas amount, and the occurrence of coking can be suppressed. Thus, the reforming performance by the reformer can be improved.

  Embodiments of an internal combustion engine according to the present invention will be described below in detail with reference to the drawings. In addition, this invention is not limited by this Example.

  FIG. 1 is a schematic configuration diagram showing an internal combustion engine according to an embodiment of the present invention, FIG. 2 is a graph showing a reformed gas component concentration with respect to a fuel injection amount in the reformer, and FIG. 3 is a reformer. FIG. 4 is a graph showing a control region of the reformer in the internal combustion engine of the present embodiment.

  In the internal combustion engine of the present embodiment, as shown in FIG. 1, the engine 11 as the internal combustion engine is a port injection type four-cylinder type, and although not shown, a cylinder head is fastened on a cylinder block, Pistons are fitted in a plurality of cylinder bores so as to be movable up and down. A crankcase is fastened to the lower part of the cylinder block, a crankshaft is rotatably supported in the crankcase, and each piston is connected to the crankshaft via a connecting rod.

  Combustion chambers 12 are formed by cylinder blocks, cylinder heads, and pistons corresponding to four cylinders, and each combustion chamber 12 is formed with an intake port 13 and an exhaust port 14 facing each other at the top. The intake port 13 and the exhaust port 14 can be opened and closed by an intake valve and an exhaust valve (not shown).

  The downstream end of the intake pipe (intake passage) 15 is connected to each intake port 13 via an intake manifold 16, and an air cleaner 17 is attached to the upstream end of the intake pipe 15. An electronic throttle device 19 having a throttle valve 18 is provided on the downstream side of the air cleaner 17. Further, the intake manifold 16 is provided with a first injector (first fuel supply means) 20 capable of supplying fuel to the intake port 13 corresponding to each combustion chamber 12. The first injector 20 is connected to a fuel pump 23 in a fuel tank 22 by a fuel supply pipe 21. Although not shown, each combustion chamber 12 is equipped with a spark plug that ignites the air-fuel mixture. Similar to the first injector 20, the second injector 30 is connected to a fuel pump 23 in the fuel tank 22 by a fuel supply pipe 21.

  On the other hand, an exhaust pipe (exhaust passage) 25 is connected to each exhaust port 14 via an exhaust manifold 24, and a reformer 26 and a three-way catalyst 27 are attached to the exhaust pipe 25. As will be described later, the reformer 26 supplies fuel to a part of the exhaust gas, and then reforms the mixed gas with exhaust heat to generate a reformed gas. The three-way catalyst 27 can simultaneously purify harmful substances such as hydrocarbons (HC), carbon monoxide (CO), and nitrogen oxides (NOx) contained in the exhaust gas. When exhaust gas is in the vicinity of the stoichiometric air-fuel ratio (stoichiometric), harmful substances in the exhaust gas can be purified.

  Here, the reformer 26 will be described in detail. The reformer 26 is arranged with a cylindrical body 26a connected to the exhaust pipe 25 and a plurality of chambers communicating with each other in the cylindrical body 26a, and a reforming catalyst (for example, Co, Ni, Rh) is disposed inside. And a gas insertion passage 26c formed between the plurality of reforming chambers 26b in the cylindrical body 26a. An exhaust gas branch pipe (road exhaust gas branch path) 28 is branched from the upstream side of the reformer 26 in the exhaust pipe 25, and the downstream end of the exhaust gas branch pipe 28 is connected to the reformer 26. It is connected to one end of the reforming chamber 26b. The exhaust gas branch pipe 28 is provided with a second injector (second fuel supply means) 29 that injects fuel to a part of the exhaust gas branched from the exhaust pipe 25 to the exhaust gas branch pipe 28. ing.

  A reformed gas introduction pipe (reformed gas introduction passage) 30 for introducing the reformed gas generated by the reformer 26 into the intake pipe 15 is provided at the other end of the reforming chamber 26 b in the reformer 26. Is connected to the downstream side of the electronic throttle device 19 in the intake pipe 15. The reformed gas introduction pipe 30 is equipped with a flow rate adjusting valve 31 that controls the amount of reformed gas introduced into the intake pipe 15. Further, the upstream side and the downstream side of the reformer 26 in the exhaust pipe 25 are communicated with each other through a gas insertion passage 26c.

  In the engine 11 of this embodiment, fuel is injected into the intake air flowing through the intake port 13 by the first injector 20, and fuel is injected into the exhaust gas flowing through the exhaust gas branch pipe 28 by the second injector 29. The fuel injection by the first injector 20 is referred to as intake fuel injection, and the fuel injection from the second injector 29 is referred to as exhaust fuel injection.

  Therefore, in a state where the flow rate adjustment valve 31 is opened, a part of the exhaust gas flowing through the exhaust pipe 25 is diverted to the exhaust gas branch pipe 28, and the second injector 29 injects fuel into the exhaust gas (exhaust fuel). Injection). The mixed gas in which the fuel and the exhaust gas are mixed flows into the reforming chamber 26b of the reformer 26, and is heated by the heat of the exhaust gas flowing from the exhaust pipe 25 through the gas insertion passage 26c of the reformer 26. Then, the mixed gas is vaporized by promoting evaporation, and the vaporized mixed gas undergoes an endothermic reaction to be reformed to generate a reformed gas containing hydrogen, carbon monoxide and the like.

For example, when the exhaust gas is “7.6 CO ₂ + 6.8H ₂ O + 40.8N ₂ ” and the gasoline fuel is “C _7.6 H _13.6 ”, the endothermic reaction is
1.56 (7.6 CO ₂ +6.8 H ₂ O + 40.8 N ₂ ) +3 (C _7.6 H _13.6 ) +984.8 kcal → 31 H ₂ +34.7 CO + 63.6 N ₂
It is represented by That is, according to the endothermic reaction at this time, 31 moles of hydrogen gas and 34.7 moles of carbon monoxide gas are generated from 3 moles of gasoline fuel.

  The reformed gas generated in the reformer 26 flows from the reforming chamber 26 b to the reformed gas introduction pipe 30, the supply amount thereof is adjusted by the opening degree of the flow rate adjusting valve 31, and the intake gas flowing through the intake pipe 15 is adjusted. Supplied. Then, an air-fuel mixture obtained by mixing the intake air and the reformed gas is introduced from the intake manifold 16 through the intake port 13 into the combustion chamber 12 and ignited by the spark plug to explode. When the exhaust valve is opened, the exhaust gas is exhausted. The gas is discharged from the port 14 to the exhaust pipe 25. In this case, since the reformed gas contains hydrogen, combustion efficiency in the combustion chamber 12 is good, fuel efficiency can be improved, and generation of NOx can be suppressed and exhaust purification efficiency can be improved.

  An electronic control unit (ECU) 32 is mounted on the vehicle, and the ECU 32 controls the drive of the first injector 20, the second injector 29, the spark plug, and the like, so that the fuel injection amount, the injection timing, the ignition timing, etc. Can be controlled. That is, an air flow sensor 33 is mounted on the upstream side of the intake pipe 15 and outputs the measured intake air amount to the ECU 32. The electronic throttle device 19 has a throttle position sensor and outputs the current throttle opening to the ECU 32. Further, the crank angle sensor 34 outputs the detected crank angle of each cylinder to the ECU 32, and the ECU 32 determines each stroke of intake, compression, expansion (explosion), and exhaust in each cylinder based on the detected crank angle. At the same time, the engine speed is calculated.

  Therefore, the ECU 32 determines the overall fuel injection amount, injection timing, ignition timing, etc. based on the detected intake air amount, throttle opening (or accelerator opening), engine operating conditions such as engine speed. Yes. In this case, the total fuel injection amount is the sum of the fuel injection amounts injected by the first injector 20 and the second injector 29.

  In addition, the ECU 32 can control the amount of reformed gas introduced into the intake pipe 15 by driving and controlling the second injector 29, the flow rate adjusting valve 31, and the like. That is, the reforming chamber 26 b of the reformer 26 is provided with a bed temperature sensor 35, and outputs the current temperature (bed temperature) of the reforming chamber 26 b to the ECU 32.

  Therefore, the ECU 32 determines whether the reformer 26 is at the activation temperature based on the detected bed temperature of the reformer 26. Further, the ECU 32 calculates an upper limit value of the amount of exhaust gas that can be recirculated to the intake pipe 15 based on the engine speed and the engine load (for example, throttle opening). When it is determined that the temperature of the reformer 26 is equal to or higher than the activation temperature, the ECU 32 calculates the amount of reformed gas that can be introduced into the intake pipe 15 based on the amount of exhaust gas that can be recirculated to the intake pipe 15. The opening degree of the flow rate adjustment valve 31 is set, and the exhaust fuel injection amount by the second injector 29 is set. In this case, the first injector 20 is injected by subtracting the exhaust fuel injection amount by the second injector 29 set here from the total fuel injection amount calculated based on the intake air amount, the engine speed, and the like. The intake fuel injection amount to be set is set.

By the way, as described above, the reforming catalyst carried in the reforming chamber 26b of the reformer 26 is mixed with exhaust gas and fuel when the bed temperature becomes a predetermined activation temperature (for example, 600 ° C.) or higher. A good reformed gas can be generated by promoting the gas reforming reaction. However, when the internal combustion engine is started or operated at a light load, it becomes difficult to sufficiently heat the reforming catalyst by the heat of the exhaust gas, and the generation of the reformed gas becomes insufficient. Then, not only a sufficient amount of reformed gas cannot be introduced into the combustion chamber, but reforming does not proceed sufficiently to hydrogen (H ₂ ) and carbon monoxide (CO), and carbon (C) is generated, A problem referred to as coking that adheres to the reformer (reforming catalyst) occurs, and the catalyst performance is degraded.

  Therefore, in the present embodiment, the ECU 32 as the fuel supply amount control means has the reforming catalyst in which the fuel injection amount (supplied fuel amount) injected by the second injector 29 is carried in the reforming chamber 26b of the reformer 26. By controlling the second injector 29 so as to be within a control region set based on the bed temperature and the amount of reformed gas introduced into the intake pipe 15 through the reformed gas introduction pipe 30, reforming is performed. The gas can be generated satisfactorily to prevent coking and improve the catalyst performance.

  In the reformer 26, the mixed gas of fuel and exhaust gas is heated by the heat of the exhaust gas, and a reformed gas is generated by an endothermic reaction. If reforming is insufficient, hydrogen or carbon monoxide is generated. In addition, carbon and other components that cause coking are included.

As shown in FIG. 2, when the fuel injection amount from the second injector 29 to the exhaust gas introduced into the reformer 26 increases, the gas concentrations of hydrogen (H ₂ ) and carbon monoxide (CO) increase. When the gas concentration of carbon dioxide (CO ₂ ) and water (H ₂ O) decreases and reaches a predetermined fuel injection amount Q1, carbon (C) is generated, and the gas concentration increases as the fuel injection amount increases. Will increase. As shown in FIG. 3, when the catalyst bed temperature in the reforming chamber 26b of the reformer 26 rises, carbon (C), water (H ₂ O), carbon dioxide (CO ₂ ), methane (CH ₄ ). When the gas concentration of hydrogen (H ₂ ) and carbon monoxide (CO) increases and reaches the predetermined catalyst bed temperature T1, the carbon (C) disappears and the fuel injection amount increases. Along with this, the gas concentrations of hydrogen (H ₂ ) and carbon monoxide (CO) become substantially constant.

  For this reason, the content (concentration) of carbon (C) as a component that generates coking in the reformed gas when the reformer 26 generates the reformed gas is the exhaust gas supplied to the exhaust gas. It can be seen that the fuel injection amount and the catalyst bed temperature of the reformer 26 are greatly affected. Further, since the exhaust fuel injection amount is set based on the amount of reformed gas introduced into the intake pipe 15 through the reformed gas introduction tube 30, the content (concentration) of carbon (C) in the reformed gas ) Depends on the amount of the reformed gas. Therefore, in this embodiment, the control region of the exhaust fuel injection amount injected by the second injector 29 is set to the intake pipe 15 through the reformed gas introduction pipe 30 with respect to the catalyst bed temperature of the reformer 26 as shown in FIG. Is set as the ratio of the exhaust fuel injection amount (fuel injection amount / reformed gas amount) to the reformed gas amount introduced into the engine. Then, the exhaust fuel injection amount is set so that the relationship among the catalyst bed temperature, the reformed gas amount, and the exhaust fuel injection amount falls within this control region.

  This control region is set such that when the catalyst bed temperature of the reformer 26 increases, the ratio of the exhaust fuel injection amount in the reformed gas amount increases, and when the catalyst bed temperature is low, the exhaust fuel injection amount is decreased. By doing so, it is set so that carbon is not generated in the reformed gas. Although it is efficient to adjust the exhaust fuel injection amount so as to be on the upper limit side of the control region by the control of the second injector 29 by the ECU 32, the upper limit value of the control region is considered in consideration of control variation and the like. It is preferable to adjust the exhaust fuel injection amount so that the lower limit side is reached.

  Therefore, the ECU 32 calculates the total fuel injection amount from the engine speed, the intake air amount, and the like, while determining the maximum exhaust gas amount that can be recirculated to the intake pipe 15 from the engine speed, the throttle opening (engine load), and the like. The amount of reformed gas that can be introduced into the intake pipe 15 is calculated from the maximum amount of exhaust gas and the catalyst bed temperature of the reformer 26, and the opening degree of the flow control valve 31 is set. Then, based on the catalyst bed temperature of the reformer 26 and the reformed gas amount introduced into the intake pipe 15 through the reformed gas introduction pipe 30, the fuel injection amount is controlled using the control map of FIG. The exhaust fuel injection amount injected by the second injector 29 is set so as to enter the region. Further, the intake fuel injection amount to be injected by the first injector 20 is set by subtracting the exhaust fuel injection amount by the second injector 29 from the entire fuel injection amount.

  Therefore, the exhaust gas discharged to the exhaust pipe 25 of the engine 11 flows through the gas insertion passage 26 c of the reformer 26 and flows into the three-way catalyst 27, and part of the exhaust gas enters the exhaust gas distribution pipe 28. A predetermined amount of fuel is injected from the second injector 29 to the exhaust gas, and a mixed gas of fuel and exhaust gas flows into the reforming chamber 26 b of the reformer 26. Then, the mixed gas flowing into the reforming chamber 26b is heated by the heat of the exhaust gas flowing through the gas insertion passage 26c, undergoes an endothermic reaction, is reformed, and a reformed gas containing hydrogen, carbon monoxide, or the like is generated. The At this time, since the exhaust fuel injection amount is adjusted so as to fall within a predetermined control region based on the catalyst bed temperature and the reformed gas amount of the reformer 26, the carbon (C) in the reforming chamber 26b is adjusted. Is suppressed, and a high quality reformed gas is generated.

  The reformed gas generated in the reforming chamber 26 b flows into the reformed gas introduction pipe 30, and the supply amount thereof is adjusted by the opening degree of the flow rate adjusting valve 31, and is supplied to the intake air flowing through the intake pipe 15. Is done. Then, the air-fuel mixture in which the intake air and the reformed gas are mixed is introduced from the intake manifold 16 through the intake port 13 into the combustion chamber 12, and is ignited by the spark plug to explode and enable good combustion. When the exhaust valve is opened, the exhaust gas is discharged from the exhaust port 14 to the exhaust pipe 25. In this case, since the reformed gas contains hydrogen and carbon monoxide, combustion efficiency in the combustion chamber 12 is good, a large amount of exhaust gas can be recirculated, and fuel efficiency can be improved. Further, carbon dioxide contained in the exhaust gas can be returned to the combustion chamber 12 to be recombusted, and NOx generation can be suppressed by lowering the combustion temperature, thereby improving exhaust purification efficiency. it can.

  As described above, in the internal combustion engine of the present embodiment, the reformer 26 is connected via the exhaust gas branch pipe 28 that splits a part of the exhaust gas flowing through the exhaust pipe 25, and the exhaust gas branch pipe 28. The second injector 29 is attached to the reformer 26, and a reformed gas introduction pipe 60 and a flow rate adjusting valve 31 for introducing the reformed gas generated by the reformer 26 into the intake pipe 15 are provided. The fuel injection amount to be injected is within a control region set based on the bed temperature of the reforming catalyst of the reformer 26 and the reformed gas amount introduced into the intake pipe 15 through the reformed gas introduction pipe 30. Thus, the second injector 29 is controlled.

  Accordingly, the fuel injection amount of the second injector 29 can be set to an optimum amount based on the bed temperature and the reformed gas amount of the reforming catalyst of the reformer 26, and the carbon (C) contained in the reformed gas. By reducing the amount, the occurrence of coking in the reformer 26 can be suppressed, and as a result, the reforming performance of the reformer 26 can be improved.

  Further, the control region for controlling the exhaust fuel injection amount of the second injector 29 is set according to the ratio of the exhaust fuel supply amount / reformed gas amount with respect to the bed temperature of the reforming catalyst of the reformer 26. The ratio of the exhaust fuel supply amount / reformed gas amount with respect to the bed temperature is in a region equal to or smaller than a predetermined ratio set in advance, that is, carbon is not generated in the reformed gas generated by the reformer 26. The exhaust fuel supply amount is controlled.

  Therefore, by preparing the control map in advance, the exhaust fuel injection amount of the second injector 29 can be easily controlled, and the occurrence of coking in the reformer 26 and the three-way catalyst 27 can be reliably suppressed. it can.

  In the above-described embodiment, the bed temperature of the reforming catalyst in the reforming chamber 26b in the reformer 26 is measured by the bed temperature sensor 35. However, the engine operating state such as the engine speed, the intake air amount, and the accelerator opening degree is used. May be obtained by estimation based on the above. In addition, the amount of reformed gas introduced into the intake pipe 15 is calculated based on engine operating conditions such as engine speed, accelerator opening, and catalyst bed temperature, but the flow rate adjustment valve 31 in the reformed gas introduction pipe 30 is opened. It may be calculated from the degree, or may be measured by providing a flow meter downstream of the flow rate adjustment valve 31 in the reformed gas introduction pipe 30.

  As described above, the internal combustion engine according to the present invention controls the fuel injection amount to the reformer 26 to be within the control region set based on the bed temperature of the reformer and the reformed gas introduction amount. Thus, the occurrence of coking is suppressed, which is useful for any internal combustion engine.

1 is a schematic configuration diagram illustrating an internal combustion engine according to an embodiment of the present invention. It is a graph showing the reformed gas component density | concentration with respect to the fuel injection quantity in a reformer. It is a graph showing the reformed gas component density | concentration with respect to the catalyst bed temperature in a reformer. It is a graph showing the control area | region of the reformer in the internal combustion engine of a present Example.

Explanation of symbols

11 Engine (Internal combustion engine)
12 Combustion chamber 13 Intake port 14 Exhaust port 15 Intake pipe (intake passage)
19 Electronic throttle device 20 First injector (first fuel supply means)
25 Exhaust pipe (exhaust passage)
26 reformer 26a cylinder 26b reforming chamber 26c gas insertion path 27 three-way catalyst 28 exhaust gas branch pipe (exhaust gas branch path)
29 Second injector (second fuel supply means)
30 Reformed gas introduction pipe (reformed gas introduction passage)
31 Flow control valve 32 Electronic control unit, ECU (fuel injection control means)
33 Airflow sensor 34 Crank angle sensor 35 Bed temperature sensor

Claims (3)

  An intake passage for introducing outside air into the combustion chamber, first fuel supply means for supplying fuel to the intake passage or the combustion chamber, an exhaust passage for exhausting exhaust gas discharged from the combustion chamber to the outside, and the exhaust An exhaust gas diversion passage for diverting a part of the exhaust gas flowing through the passage, a second fuel supply means for supplying fuel to the exhaust gas diversion passage, and the exhaust supplied with fuel from the second fuel supply means A reformer configured to generate a reformed gas by introducing an exhaust gas flowing through the gas diversion passage; a reformed gas introduction passage configured to introduce the reformed gas generated by the reformer into the intake passage; Control in which the amount of fuel supplied by the two fuel supply means is set based on the bed temperature of the reforming catalyst carried on the reformer and the amount of reformed gas introduced into the intake passage through the reformed gas introduction passage Controlling the second fuel supply means so as to be within the region; Internal combustion engine, characterized in that it comprises a charge supply amount control means.   2. The internal combustion engine according to claim 1, wherein the control region is a region where a ratio of a second fuel supply amount / reformed gas amount to a bed temperature of the reforming catalyst is equal to or less than a predetermined ratio set in advance. A characteristic internal combustion engine. 3. The internal combustion engine according to claim 1, wherein the control region is a region where carbon is not generated in the reformed gas generated by the reformer.

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