JP2010151042A - Internal combustion engine with fuel reformulation system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an internal combustion engine with a fuel reformulation system inhibiting deterioration of combustion even when reformed gas is not formed. <P>SOLUTION: Exhaust gas taken out from a branch pipe 30 flows into an intake air passage 14 through a reformed gas conduit 34 via a heat exchanger 24. Exhaust gas taken out from the exhaust gas conduit 40 flows into an intake air passage 14 through the exhaust gas conduit 40. Since the exhaust gas conduit 40 is branched off from the exhaust gas passage 22 at a downstream side of the heat exchanger 24, exhaust gas of low temperatures relatively to exhaust gas flowing through a branch pipe 30 branching off from the exhaust gas passage at an upstream side of the heat exchanger 24 is supplied into the intake air passage 14. Consequently, deterioration of combustion is inhibited even when reformed gas is not formed. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an internal combustion engine with a fuel reforming system, and more particularly, with a fuel reforming system that recirculates a reformed gas obtained by reforming an air-fuel mixture of exhaust gas and reforming fuel to the internal combustion engine. The present invention relates to an internal combustion engine.

  Conventionally, for example, Patent Document 1 discloses an internal combustion engine with a fuel reforming system in which a reformed gas is generated from a part of exhaust gas flowing through an exhaust passage of an internal combustion engine and reforming fuel and is returned to the intake passage of the internal combustion engine. Is disclosed. In this internal combustion engine, a reformer having a fuel reforming catalyst is used for generation of reformed gas, and this reformer is communicated with an intake passage of the internal combustion engine and a reformed gas passage. For this reason, the reformed gas can be recirculated to the internal combustion engine through the reformed gas passage. The reformed gas is a gas containing hydrogen gas. Therefore, it is possible to suppress the deterioration of combustion due to the rapid combustion of hydrogen gas and the suppression of knocking due to this.

  In this internal combustion engine, when the temperature of the fuel reforming catalyst is lower than the activation temperature, the generation of the reformed gas can be stopped and only the exhaust gas can be recirculated to the internal combustion engine. Therefore, the reformed gas can be effectively recirculated to the internal combustion engine while avoiding a catalyst environment in which reforming of the reforming fuel is insufficient.

JP 2006-037879 A JP 2008-202497 A JP 2006-118488 A

  By the way, it is desirable that even when the generation of the reformed gas is stopped, it is possible to suppress the deterioration of combustion and the knocking caused thereby. In Patent Document 1, a part of the exhaust gas is directly recirculated to the intake passage of the internal combustion engine. That is, a part of the exhaust gas is returned to the internal combustion engine through the reformed gas passage without being reformed.

  However, the reformer is arranged to exchange heat with the exhaust gas flowing through the reformer. For this reason, the gas flowing through the fuel reforming catalyst of the reformer exchanges heat with the high-temperature exhaust gas flowing through the reformer when passing through the gas. Therefore, the gas flowing through the fuel reforming catalyst becomes high temperature. When the high-temperature gas returns to the internal combustion engine, the combustion of the internal combustion engine may become unstable. Therefore, in Patent Document 1, there is a possibility that knocking may occur when the generation of the reformed gas is stopped.

  The present invention has been made to solve the above-described problems, and provides an internal combustion engine with a fuel reforming system capable of suppressing deterioration of combustion even when reformed gas is not generated. The purpose is to provide.

In order to achieve the above object, a first invention is an internal combustion engine with a fuel reforming system, which is disposed in an exhaust passage of the internal combustion engine and includes a part of exhaust gas flowing through the exhaust passage and a reforming fuel. A reformed gas generating means capable of generating a reformed gas containing hydrogen gas;
A reformed gas recirculation passage connected to the reformed gas generating means for recirculating the reformed gas to an intake passage of the internal combustion engine;
And an exhaust gas recirculation passage for recirculating a part of the exhaust gas in the exhaust passage downstream of the reformed gas generation means to the intake passage.

The second invention is the first invention, wherein
A first flow rate adjusting valve that adjusts the flow rate of the gas that flows back to the intake passage through the reformed gas recirculation passage;
A second flow rate adjusting valve that adjusts the flow rate of the gas that flows back to the intake passage through the exhaust gas recirculation passage;
When there is an exhaust gas recirculation request for the intake passage, the timing of exhaust gas recirculation by the first flow rate adjustment valve is slower than the timing of exhaust gas recirculation by the second flow rate adjustment valve, And a valve opening timing control means for controlling the valve opening timing of the second flow rate adjusting valve.

The third invention is the first or second invention, wherein
A first flow rate adjusting valve that adjusts the flow rate of the gas that flows back to the intake passage through the reformed gas recirculation passage;
A second flow rate adjusting valve that adjusts the flow rate of the gas that flows back to the intake passage through the exhaust gas recirculation passage;
Required exhaust gas recirculation amount acquisition means for acquiring the required exhaust gas recirculation amount;
Opening degree control means for controlling the opening degree of the first flow rate adjustment valve and the second flow rate adjustment valve according to the required exhaust gas recirculation amount,
The opening degree control means includes valve opening permission means for permitting opening of the first flow rate adjustment valve when the required exhaust gas recirculation amount cannot be achieved even when the opening degree of the second flow rate adjustment valve is fully opened. It is characterized by that.

Moreover, 4th invention is set in 3rd invention,
A reforming fuel supply means for supplying the reforming fuel to the reformed gas generating means;
Reforming condition determining means for determining whether or not the reformed gas generating means is in a predetermined condition capable of generating the reformed gas,
The reforming fuel supply unit includes a supply prohibiting unit that prohibits the supply of the reforming fuel when it is determined that the predetermined condition is not satisfied.

The fifth invention is the invention according to any one of the first to fourth inventions,
A first flow rate adjusting valve that adjusts the flow rate of the gas that flows back to the intake passage through the reformed gas recirculation passage;
A second flow rate adjusting valve that adjusts the flow rate of the gas that flows back to the intake passage through the exhaust gas recirculation passage;
Torque fluctuation detecting means for detecting fluctuations in torque of the internal combustion engine;
Torque fluctuation determination means for determining whether or not the torque fluctuation exceeds a predetermined value;
When the fluctuation of the torque exceeds a predetermined value, the flow rate of the gas returning to the intake passage through the exhaust gas recirculation passage is reduced, and the flow rate of the gas returning to the intake passage through the reformed gas recirculation passage Opening degree correction means for correcting the opening degree of the first flow rate adjustment valve and the second flow rate adjustment valve so as to increase the flow rate.

The sixth invention is the invention according to any one of the first to fifth inventions,
A first flow rate adjusting valve that adjusts the flow rate of the gas that flows back to the intake passage through the reformed gas recirculation passage;
A second flow rate adjustment valve that adjusts the flow rate of the gas that flows back to the intake passage through the exhaust gas recirculation passage;
Knocking detection means for detecting occurrence of knocking in the internal combustion engine;
When knocking occurs, the flow rate of the gas returning to the intake passage through the exhaust gas recirculation passage is decreased, and the flow rate of the reformed gas returning to the intake passage through the reformed gas recirculation passage is increased. Opening degree correction second means for correcting the opening degree of the first flow rate adjustment valve and the second flow rate adjustment valve.

The seventh invention is the sixth invention, wherein
Ignition timing control means for controlling the ignition timing to the retard side when knocking occurs,
Determination means for determining whether or not the opening correction second means is executable,
The ignition timing control means reduces the retard amount of the ignition timing when the opening degree correction second means is executable compared to when it is not executable.

The eighth invention is the invention according to any one of the first to seventh inventions,
A first flow rate adjusting valve that adjusts the flow rate of the gas that flows back to the intake passage through the reformed gas recirculation passage;
A second flow rate adjustment valve that adjusts the flow rate of the gas that flows back to the intake passage through the exhaust gas recirculation passage,
When there is a request to stop exhaust gas recirculation for the intake passage, the first flow rate is set so that the exhaust gas recirculation stop timing by the first flow rate adjustment valve is later than the exhaust recirculation stop timing by the second flow rate adjustment valve. A valve closing timing control means for controlling the valve closing timing of the adjusting valve and the second flow rate adjusting valve is provided.

The ninth invention is the eighth invention, wherein
When the stop request is at the time of deceleration of the internal combustion engine, the first flow rate adjustment valve is opened so as to temporarily increase the flow rate of the reformed gas that flows back to the intake passage through the reformed gas recirculation passage. First flow rate adjusting valve opening correction means for correcting the degree is provided.

The tenth invention is the invention according to any one of the first to ninth inventions,
A first flow rate adjusting valve that adjusts the flow rate of the gas that flows back to the intake passage through the reformed gas recirculation passage;
A second flow rate adjusting valve that adjusts the flow rate of the gas that flows back to the intake passage through the exhaust gas recirculation passage;
A reforming fuel supply means for supplying the reforming fuel to the reformed gas generating means;
A failure detection means for detecting a failure of the second flow rate adjustment valve,
The reforming fuel supply means includes supply amount control means for increasing the supply amount of the reforming fuel when the failure is detected.

  According to the first invention, the exhaust gas recirculation passage is provided separately from the reformed gas recirculation passage. The exhaust gas recirculation passage can recirculate part of the gas flowing through the exhaust passage of the internal combustion engine downstream of the reformed gas generation means to the internal combustion engine. The exhaust gas flowing through the exhaust passage of the internal combustion engine downstream from the reformed gas generating means is relatively cooler than the gas flowing through the reformed gas recirculation path via the reformed gas generating means. For this reason, even when the reformed gas is not generated, the low-temperature gas can be recirculated to the intake passage of the internal combustion engine. Therefore, according to the first invention, it is possible to suppress the deterioration of combustion even when the reformed gas is not generated.

  According to the second invention, the flow rate of the gas recirculated through the reformed gas recirculation passage and the flow rate of the gas recirculated through the exhaust gas recirculation passage are respectively determined by the first flow rate adjustment valve and the second flow rate adjustment valve. Can be adjusted. Further, when exhaust gas recirculation is performed, the first flow rate adjustment valve and the second flow rate adjustment valve can be controlled such that the gas passing through the exhaust gas recirculation passage is recirculated before the gas passing through the reformed gas recirculation passage. For this reason, when performing exhaust gas recirculation, a relatively low temperature gas can be preferentially recirculated. Therefore, it is possible to further suppress the deterioration of combustion.

  According to the third aspect, when the required exhaust gas recirculation amount cannot be achieved even when the opening of the second flow rate adjustment valve is fully opened, the opening of the first flow rate adjustment valve is permitted. Therefore, it is possible to cope with a case where the required exhaust gas recirculation amount is large.

  According to the fourth aspect of the present invention, it is possible to prohibit the supply of the reforming fuel to the reforming generating means when there is no predetermined condition capable of generating the reformed gas. For this reason, the reformed gas can be effectively refluxed, and the reforming fuel can be effectively used.

  According to the fifth invention, when the torque fluctuation exceeds a predetermined value, the flow rate of the gas recirculated from the first flow rate adjustment valve is increased, and the flow rate of the reformed gas recirculated from the second flow rate adjustment valve is decreased. Can be made. Since the reformed gas is a gas containing hydrogen gas, the hydrogen gas can be increased by increasing the gas flow rate recirculated from the first flow rate adjusting valve. Therefore, when the torque fluctuation exceeds a predetermined value, the deterioration of the torque fluctuation can be suppressed by recirculating more hydrogen gas.

  According to the sixth aspect, when knocking occurs, the flow rate of the gas recirculated from the first flow rate adjustment valve can be increased, and the flow rate of the reformed gas recirculated from the second flow rate adjustment valve can be decreased. Therefore, knocking can be eliminated by refluxing more reformed gas.

  According to the seventh aspect, in the ignition timing control, when the flow rate of the gas recirculated from the first flow rate adjustment valve can be increased and the flow rate of the reformed gas recirculated from the second flow rate adjustment valve can be decreased. Can reduce the retard amount of the ignition timing. If the ignition timing is retarded when knocking occurs, knocking can be eliminated, but the torque is reduced. Therefore, when the flow rate of the gas recirculated from the first flow rate adjustment valve can be increased and the flow rate of the reformed gas recirculated from the second flow rate adjustment valve can be decreased, the reformed gas is recirculated more. It is possible to eliminate knocking and reduce the retard amount of the ignition timing to suppress torque reduction.

  According to the eighth invention, when there is a request to stop exhaust gas recirculation, the first flow rate adjustment is performed so that the gas flowing through the reformed gas recirculation passage is recirculated to the intake passage after the recirculation of the gas flowing through the exhaust gas recirculation passage is stopped. The valve closing timing of the valve and the second flow rate adjustment valve can be controlled. For this reason, when the exhaust gas recirculation is stopped, the reformed gas-containing gas flowing in the reformed gas recirculation passage can be recirculated to a relatively later time than the gas flowing in the exhaust gas recirculation passage. Therefore, the generated reformed gas can be used efficiently.

  According to the ninth aspect, when the exhaust gas recirculation stop request is made at the time of deceleration of the internal combustion engine, a large amount of the reformed gas can be recirculated to the intake passage temporarily. As a result, a large amount of the reformed gas remains in the intake passage, and the responsiveness when performing re-acceleration can be improved.

  According to the tenth aspect, the supply amount of reforming fuel can be increased when a failure of the second flow rate adjustment valve is detected. When the second flow rate adjusting valve fails, it becomes impossible to recirculate a relatively low temperature gas by a desired amount. For this reason, the temperature of the exhaust gas discharged from the internal combustion engine may become high. Therefore, the supply amount of the reforming fuel is increased, and the temperature rise of the reformed gas generating means is prevented. Therefore, when the second flow rate adjusting valve fails, it is possible to prevent thermal deterioration of the reformed gas generating means.

  Embodiments of the present invention will be described below with reference to the drawings. In the drawings, the same or corresponding parts are denoted by the same reference numerals, and the description thereof is simplified or omitted.

Embodiment 1 FIG.
[Description of system configuration]
FIG. 1 is a diagram for explaining a system configuration according to the first embodiment of the present invention. As shown in FIG. 1, the system of the present embodiment includes an internal combustion engine 10. An intake passage 14 is connected to each cylinder of the internal combustion engine 10 via an intake manifold 12.

  A fuel injection device 16 is provided in the intake passage 14. An air flow meter 18 for measuring the intake air amount is installed upstream of the intake passage 14. The air flowing through the intake passage 14 via the air flow meter 18 forms a mixture with the fuel injected from the fuel injection device 16 into the intake passage 14 and flows into each cylinder of the internal combustion engine 10. Note that, unlike the illustrated configuration, the fuel injection device 16 may be a fuel injection device that directly injects fuel into each cylinder.

  An exhaust passage 22 is connected to each cylinder of the internal combustion engine 10 via an exhaust manifold 20. A heat exchanger 24 is installed in the middle of the exhaust passage 22. A reforming chamber 26 and an exhaust passage 28 are formed in the heat exchanger 24. The reforming chamber 26 and the exhaust passage 28 are separated by a partition wall, and the exhaust gas flowing in from the exhaust passage 22 passes through the exhaust passage 28.

  A fuel reforming catalyst is carried in the reforming chamber 26. As a component of this fuel reforming catalyst, for example, Rh, Co, Ni and the like are preferably used. By using the heat exchanger 24, the reforming chamber 26 can be heated by the heat of the exhaust gas that passes through the exhaust passage 22.

  One end of a branch pipe 30 for extracting a part of the exhaust gas is connected to the exhaust passage 22 upstream of the heat exchanger 24. The other end of the branch pipe 30 communicates with the reforming chamber 26 of the heat exchanger 24. In the middle of the branch pipe 30, a reforming fuel supply device 32 that injects reforming fuel into the exhaust gas passing through the branch pipe 30 is installed.

  The exhaust gas taken out by the branch pipe 30 and the fuel injected from the reforming fuel supply device 32 flow into the reforming chamber 26. At this time, a reforming reaction is caused by the action of the fuel reforming catalyst. The reformed gas generated by this reforming reaction is a gas containing hydrogen gas, and flows into the intake passage 14 through the reformed gas conduit 34. The reformed gas is mixed with the intake air flowing through the intake passage 14 via the air flow meter 18. A cooler 36 for cooling the gas flowing in the reformed gas conduit 34 is installed in the middle of the reformed gas conduit 34. A flow rate adjustment valve 38 for adjusting the mixing ratio of the reformed gas to the intake air is installed in the vicinity of the connection portion between the reformed gas conduit 34 and the intake passage 14.

  One end of an exhaust gas conduit 40 for extracting a part of the exhaust gas is connected to the exhaust passage 22 on the downstream side of the heat exchanger 24. The other end of the exhaust gas conduit 40 is connected to the intake passage 14. The exhaust gas flowing through the exhaust gas conduit 40 is mixed with the intake air flowing through the intake passage 14 via the air flow meter 18. In the middle of the exhaust gas conduit 40, a cooler 42 for cooling the gas flowing through the exhaust gas conduit 40 is installed. A flow rate adjusting valve 44 for adjusting the mixing ratio of the reformed gas to the intake air is provided in the vicinity of the connection portion between the exhaust gas conduit 40 and the intake passage 14.

  The system of this embodiment further includes an ECU (Electronic Control Unit) 50. The ECU 50 is electrically connected to various actuators such as the fuel injection device 16, the air flow meter 18, the reforming fuel supply device 32, and the flow rate adjustment valves 38 and 44 described above. Various sensors such as a crank angle sensor 52 and an in-cylinder pressure sensor 54 are electrically connected to the ECU 50.

  When the internal combustion engine 10 is operated, the exhaust gas flowing through the exhaust passage 22 returns to the intake passage 14 through the reformed gas conduit 34 and the exhaust gas conduit 40, respectively. That is, two external EGRs (Exhaust Gas Recirculation) using the reformed gas conduit 34 and the exhaust gas conduit 40 are performed. In the system of the present embodiment, these two external EGRs are controlled according to the operating state of the internal combustion engine 10, the required exhaust gas recirculation amount (required EGR amount), and the like.

  FIG. 2 is a diagram for explaining a mechanism for controlling the above-described two EGRs according to the operating state (the rotational speed and the load) of the internal combustion engine 10. In the system of the present embodiment, when there is a request for EGR, only the flow rate adjustment valve 44 is opened in the case of low rotation and low load. On the other hand, in the case of high rotation and high load, the flow rate adjustment valve 38 is opened together with the flow rate adjustment valve 44.

  The two EGRs are controlled in this way because the progress of the reforming reaction correlates with the state of the fuel reforming catalyst in the reforming chamber 26. That is, the state of the fuel reforming catalyst is activated in a certain temperature range. In other words, the fuel reforming catalyst is not in an active state outside the temperature range, and the reforming reaction does not proceed sufficiently. Therefore, in the system of the present embodiment, such a temperature range is determined using the operating state, and the flow rate adjusting valves 38 and 44 are controlled to open and close according to the operating state.

  Specifically, when the fuel reforming catalyst is not in an active state, first, EGR from the exhaust passage 22 on the downstream side of the heat exchanger 24 is executed. By doing so, gas having a relatively lower temperature than the upstream side can be returned to the intake passage 14. This is because the exhaust gas discharged from the internal combustion engine 10 loses heat to the exhaust passage 22 as it flows through the exhaust passage 22. Therefore, since the mixed gas with the intake air can be suppressed from being introduced into the internal combustion engine 10 at a high temperature, the deterioration of combustion can be suppressed and the occurrence of knocking can be suppressed.

  On the other hand, when the fuel reforming catalyst is in an active state, the flow control valve 44 is controlled to recirculate the exhaust gas having a relatively low temperature, and at the same time, the flow control valve 38 is controlled to recirculate the reformed gas. . Although the pump loss can be reduced by executing the EGR, the combustion rate deteriorates because the combustion rate becomes slow as the EGR amount increases. As a result, the output torque of the internal combustion engine 10 decreases and drivability deteriorates. For this reason, the reformed gas containing hydrogen gas is refluxed. This hydrogen gas can burn rapidly. Therefore, if the gas containing hydrogen gas is refluxed, deterioration of combustion accompanying an increase in the EGR amount can be suppressed. Thereby, deterioration of combustion can be suppressed.

  Further, in the system according to the present embodiment, the two EGRs described above are controlled according to the required EGR amount (EGR rate). FIG. 3 is a diagram for explaining the operation of the flow rate adjusting valves 38 and 44 when the two EGRs described above are controlled according to the required EGR amount. 3A shows the relationship between the required EGR amount and the opening degree of the flow rate adjustment valve 38, and FIG. 3B shows the relationship between the required EGR amount and the opening degree of the flow rate adjustment valve 44, respectively.

  As shown in FIG. 3B, when the required EGR amount is small, opening / closing control of the flow rate adjustment valve 44 is executed. Therefore, the required EGR amount can be achieved only by opening / closing control of the flow rate adjustment valve 44, and can be dealt with by EGR from the exhaust passage 22 on the downstream side of the heat exchanger 24.

  On the other hand, when the required EGR amount increases and cannot be achieved even when the flow rate adjustment valve 44 is fully opened, the control for fully opening the flow rate adjustment valve 44 shown in FIG. As shown, the opening / closing control of the flow rate adjustment valve 38 is executed, and the EGR from the exhaust passage 22 on the upstream side of the heat exchanger 24 is also used. By doing so, the shortage of the required EGR amount can be compensated. At this time, since the flow rate adjusting valve 44 is fully opened, the gas flowing through the intake passage 14 includes a lot of gas having a relatively low temperature. Therefore, even when the combustion reforming catalyst is not in an active state, deterioration of combustion can be suppressed and occurrence of knocking can be suppressed.

  Here, the required EGR amount can be calculated from the engine speed and the load. The required EGR amount (rate) can be calculated from the difference (current calculated value−previous calculated value) or ratio (current calculated value / previous calculated value) between the previous calculated value and the current calculated value of the requested EGR amount. It is assumed that the required EGR amount is stored in the ECU 50 every time it is calculated.

[Specific Processing in Embodiment 1]
FIG. 4 is a flowchart of a routine executed by the ECU 50 in order to realize the above function. According to the routine shown in FIG. 4, it is first determined whether or not a valve opening command for the flow rate adjusting valve has been issued (step 100). Specifically, when the required EGR amount is calculated in the ECU 50, it is determined that a valve opening command has been issued. When it is determined that the valve opening command has not been issued, this routine is temporarily terminated.

  If it is determined that the valve opening command has been issued, it is determined whether or not the fuel reforming catalyst carried in the reforming chamber 26 is in the reformable region (step 120). As described above, the state of the fuel reforming catalyst is determined by the operating state of the internal combustion engine 10. If it is determined that the reformable region is not present, no reformed gas is expected to be generated even if the reforming fuel is supplied, and therefore the reforming fuel injection into the heat exchanger 24 is prohibited. (Step 140). On the other hand, if it is in the reformable region, injection of reforming fuel into the heat exchanger 24 is permitted (step 160).

  In step 180, the opening degree of the flow rate adjusting valve 44 is controlled according to the required EGR amount calculated in step 100. As a result, the relatively low temperature exhaust gas recirculates to the intake passage 14. Subsequently, it is determined whether or not the opening degree of the flow rate adjusting valve 44 is fully open (step 200). That is, if the required EGR amount cannot be satisfied even though the flow rate adjusting valve 44 is fully opened, the opening degree of the flow rate adjusting valve 38 is opened to the required opening degree (step 220). In this way, the EGR amount that is insufficient with only the flow rate adjusting valve 44 is added, and the required EGR amount is compensated. On the other hand, when it is determined that the opening degree of the flow rate adjustment valve 44 is not fully opened, this routine is temporarily ended.

  In step 240, as in step 180, the opening degree of the flow rate adjustment valve 44 is controlled. Subsequently, in step 260, as in step 200, it is determined whether or not the opening degree of the flow rate adjustment valve 44 is fully open. When it is determined that the opening degree of the flow rate adjustment valve 44 is fully open, the flow rate adjustment valve 38 is opened to the required opening degree to compensate for the required EGR amount (step 280). On the other hand, when it is determined that the opening degree of the flow rate adjustment valve 44 is not fully opened, this routine is temporarily ended.

  Subsequent to step 280, the reforming fuel is injected into the heat exchanger 24 (step 300). As a result, the reformed gas generated by the fuel reforming catalyst in the active state recirculates to the intake passage 14.

  According to the routine of FIG. 4 described above, the opening timing of the flow rate adjusting valve 44 can be made earlier than the opening timing of the flow rate adjusting valve 38. As a result, the low-temperature exhaust gas that has passed through the flow rate adjustment valve 44 can be preferentially recirculated into the intake passage 14. Therefore, deterioration of combustion can be suppressed and occurrence of knocking can be suppressed.

  Further, according to the routine of FIG. 4, when the required EGR amount can be achieved by the control of the flow rate adjustment valve 44, the opening of the flow rate adjustment valve 38 can be prohibited. Therefore, when the required EGR amount can be achieved by controlling the flow rate adjusting valve 44, only the low-temperature exhaust gas that has passed through the flow rate adjusting valve 44 can be recirculated. Further, even when both the flow rate adjusting valves 38 and 44 are opened, the exhaust gas having a low temperature passing through the flow rate adjusting valve 44 is recirculated relatively more than the gas passing through the flow rate adjusting valve 38. Can do. Therefore, deterioration of combustion can be suppressed and occurrence of knocking can be suppressed.

  Further, according to the routine of FIG. 4, when the fuel reforming catalyst is not in an active state, the supply of the reforming fuel can be prohibited. As a result, the reforming fuel can be used effectively and the reformed gas can be generated effectively.

  In the first embodiment described above, one end of the exhaust gas conduit 40 is connected to the intake passage 14, but one end of the exhaust gas conduit 40 may be connected to the intake port of the internal combustion engine 10. Specifically, this is as shown in FIG. That is, the exhaust gas conduit 40 may be connected to the intake port of the intake manifold 12 via the connection ports 46a to 46d. According to the EGR from the exhaust passage 22 on the downstream side of the heat exchanger 24, a gas having a relatively lower temperature than the EGR on the upstream side can be recirculated. In addition, since the gas having a relatively low temperature is directly supplied to each cylinder via the connection ports 46a to 46d, it is possible to further suppress the deterioration of combustion and the occurrence of knocking. The present modification can be similarly applied to Embodiments 2 to 6 described later.

  In the first embodiment described above, the heat exchanger 24 is the “reformed gas generating means” in the first invention, and the reformed gas conduit 34 is the “reformed gas reflux passage” in the first invention. The exhaust gas conduit 40 corresponds to the “exhaust gas recirculation passage” in the first aspect of the invention.

  In the first embodiment described above, the flow rate adjustment valve 38 is the “first flow rate adjustment valve” in the second invention, and the flow rate adjustment valve 44 is the “second flow rate adjustment valve” in the second invention. , Respectively. Further, the “valve opening timing control means” in the second aspect of the present invention is realized by the ECU 50 executing the processing of steps 100 to 180 and 240 of FIG.

  Further, in the first embodiment described above, the “required exhaust gas recirculation amount acquisition means” in the third aspect of the present invention is obtained when the ECU 50 calculates and stores the required EGR amount based on the rotational speed and load of the internal combustion engine 10. By executing the processing of steps 100 and 180 to 280 in FIG. 4, the “opening degree control means” in the third invention executes the processing of steps 200 and 220 or steps 260 and 280 in FIG. 4. The “valve opening permission means” in the third aspect of the invention is realized.

  In the first embodiment described above, the reforming fuel supply device 32 corresponds to the “reforming fuel supply means” in the fourth invention. Further, when the ECU 50 executes the process of step 120 of FIG. 4, the “reforming condition determining means” in the fourth invention executes the process of step 140 of FIG. "Supply prohibiting means" is realized respectively.

Embodiment 2. FIG.
In the system of this embodiment, when the injection of reforming fuel into the heat exchanger 24 is permitted in the configuration of FIG. 1, torque fluctuations are detected and the flow rate adjustment valves 38 and 44 are opened. It is characterized by controlling.

  When the deterioration of combustion occurs, the output torque of the internal combustion engine 10 may vary. For this reason, in the system of the present embodiment, in such a case, control for returning more reformed gas to the intake passage 14 is executed. As described in the first embodiment, the reformed gas is a gas containing hydrogen gas and can suppress deterioration of combustion. Therefore, if more reformed gas is recirculated, more hydrogen gas can flow in, so that fluctuations in output torque can be suppressed.

  Further, in the system of the present embodiment, control is performed to increase the opening degree of the flow rate adjustment valve 38 and reduce the opening degree of the flow rate adjustment valve 44. If the opening degree of the flow rate adjusting valve 38 is increased without changing the opening degree of the flow rate adjusting valve 44, the total amount of the EGR amount simply increases, and combustion may worsen on the contrary. For this reason, when the opening degree of the flow regulating valve 38 is increased, the opening degree of the flow regulating valve 44 is decreased. By so doing, the required EGR amount can be reliably realized and combustion deterioration can be suppressed.

  The torque fluctuation can be used as a corresponding value of the torque fluctuation by obtaining the angular acceleration of the crankshaft based on the signal acquired from the crank angle sensor 52. Also, the indicated torque can be calculated based on the signal acquired from the in-cylinder pressure sensor 54 and the signal acquired from the crank angle sensor 52, and used as a corresponding value of torque fluctuation. Further, when the internal combustion engine 10 constitutes a hybrid vehicle drive system, torque fluctuations can be directly detected by a motor generator (not shown).

[Specific Processing in Second Embodiment]
FIG. 6 is a flowchart of a routine executed by the ECU 50 in order to realize the above function. According to the routine shown in FIG. 6, first, it is determined whether or not fuel injection to the heat exchanger 24 is being performed (step 320). If fuel injection is not being executed, generation of reformed gas is not expected even if the reformed gas is supplied, and thus this routine is temporarily terminated.

  On the other hand, if it is determined that fuel injection is being performed, torque fluctuation is detected (step 340). The method for detecting torque fluctuation is as described above. Subsequently, it is determined whether or not the detected torque fluctuation has deteriorated (step 360). This determination is performed by comparing with a determination value stored in the ECU 50 separately. As a result, when it is determined that the torque fluctuation has deteriorated, the opening degree of the flow rate adjusting valve 38 is corrected to the increasing side (step 380), and the opening degree of the flow rate adjusting valve 44 is corrected to the decreasing side. (Step 400). On the other hand, when it is determined that the torque fluctuation has not deteriorated, the opening of the flow rate adjusting valves 38 and 44 is not corrected, and this routine is closed.

  According to the routine of FIG. 6 described above, when the torque fluctuation is deteriorated, the opening degree of the flow rate adjustment valve 38 is corrected to increase so as to increase the supply amount of hydrogen gas. Torque fluctuations can be suppressed.

  Further, according to the routine of FIG. 6, when the opening degree of the flow rate adjustment valve 38 is corrected to the increase side, the opening degree of the flow rate adjustment valve 44 can be corrected to the decrease side. The increase in the EGR amount accompanying the valve opening correction can be adjusted by the opening degree of the flow rate adjustment valve 44.

  In the second embodiment described above, the “torque fluctuation detecting means” in the fifth aspect of the present invention executes the process of step 360 in FIG. 6 by executing the process in step 360 of FIG. The “torque variation determination means” in the fifth invention realizes the “opening correction means” in the fifth invention by executing the processing of steps 380 and 400 of FIG.

Embodiment 3 FIG.
In the system of this embodiment, knocking is detected by the in-cylinder pressure sensor 54 or a known knock sensor (not shown) in the configuration of FIG. When knocking is detected, control for changing the opening degree of the flow rate adjusting valves 38 and 44 and control for retarding the ignition timing are executed according to the opening degree of the flow rate adjusting valves 38 and 44 at that time. The feature is to do.

  FIG. 7 is a diagram for explaining the operation of the flow rate adjusting valves 38 and 44 when knocking is detected when controlling the two EGRs described above according to the required EGR amount (EGR rate). FIG. 7A shows the relationship between the required EGR amount and the opening degree of the flow rate adjustment valve 38, and FIG. 7B shows the relationship between the required EGR amount and the opening degree of the flow rate adjustment valve 44, respectively.

  As shown as region I in FIG. 7, in the region until the flow rate adjustment valve 44 is fully opened or the region where both the flow rate adjustment valves 38, 44 are controlled to be fully open, the opening degree of the flow rate adjustment valves 38, 44. The control for changing is not executed. As already described in the description of FIG. 3, when the required EGR amount can be achieved only by controlling the flow rate adjusting valve 44, the flow rate adjusting valve 38 is not opened. Therefore, in the region until the flow rate adjustment valve 44 is fully opened, the control for changing the opening degree of the flow rate adjustment valves 38, 44 is not executed. Further, in the region where both the flow rate adjusting valves 38 and 44 are controlled to be fully opened, it is not possible to control to increase the opening degree of the flow rate adjusting valve 38. Therefore, in the region I, control for changing the opening degree of the flow rate adjusting valves 38 and 44 is not executed.

  When knocking is detected when the opening degree of the flow rate adjusting valves 38 and 44 corresponds to the above-described region I, the ignition timing retarding control (retarding amount α) is executed to eliminate the knocking.

  On the other hand, as shown as region II in FIG. 7, that is, when the region does not correspond to the region I, the required EGR amount can be achieved by simultaneously controlling the opening degree of the flow rate adjusting valves 38 and 44. . In the region II, when knocking is detected, the opening degree of the flow rate adjustment valve 38 is increased (changed from b to b ′) and the opening degree of the flow rate adjustment valve 44 is reduced (from a to a ′). Change) Control is executed. In this way, more reformed gas can be recirculated to the intake passage 14.

  In addition to the above control, ignition timing retard control (retard amount β) is executed. In some cases, knocking can be eliminated by returning the reformed gas to the intake passage 14. However, if knocking cannot be resolved even when the reformed gas is refluxed, ignition timing retard control is executed to eliminate knocking. In this case, since the reformed gas has already been refluxed, the retard amount β is set to a retard amount that is smaller than the retard amount α. By doing so, it is possible to suppress a reduction in output torque due to execution of ignition timing retard control. Also, the response to the accelerator opening can be improved.

[Specific Processing in Embodiment 3]
FIG. 8 is a flowchart of a routine executed by the ECU 50 in order to realize the above function. According to the routine shown in FIG. 8, first, occurrence of knocking is detected (step 420). If the occurrence of knocking is detected, the process proceeds to step 440. On the other hand, if the occurrence of knocking is not detected, this routine is temporarily terminated.

  In step 440, it is determined whether or not it is a region where control for changing the opening degree of the flow rate adjusting valves 38, 44 is possible. That is, it is determined whether or not it corresponds to the above-described region II. And when it does not correspond to the area II, for example, when fuel injection to the heat exchanger 24 is not being executed, the ignition timing retardation amount is set to the retardation amount α (step 460). As a result, knocking can be eliminated.

  If it is determined in step 440 that the region II corresponds to the region II, the opening degree of the flow rate adjustment valve 38 is corrected to the increase side, the supply amount of reforming fuel to the heat exchanger 24 is increased, and the flow rate adjustment valve 44. Is corrected to the decreasing side (step 480). Thereby, knocking can be eliminated while realizing the required EGR amount. Subsequent to step 480, the ignition timing retard amount is set to the retard amount β (step 500). Thereby, even if it is a case where knocking cannot be eliminated even if the reformed gas is refluxed, knocking can be eliminated.

  As described above, according to the routine shown in FIG. 8, even when knocking occurs, knocking can be reliably eliminated. Further, according to the routine shown in FIG. 8, in the region corresponding to the region II, it is possible to achieve the elimination of knocking and the suppression of the reduction in output torque by executing the retard control of the ignition timing.

  In the above-described third embodiment, the “knocking detection means” in the sixth invention by executing the process of step 420 in FIG. 8 causes the “knock detection means” in the sixth invention to execute the process in step 480 of FIG. The “opening correction second means” in the sixth aspect of the invention is realized.

  Further, in the third embodiment described above, by executing the processing of steps 460 and 500 of FIG. 8, the “ignition timing retarding control means” in the seventh invention processes the step of step 440 of FIG. As a result, the “correctable determination means” according to the seventh aspect of the present invention is realized.

Embodiment 4 FIG.
In the system according to the present embodiment, in the configuration of FIG. 1, when there is a request for full closing of the flow rate adjustment valve, the gas flowing through the reformed gas conduit 34 is in the intake passage even after the recirculation of the gas flowing through the exhaust gas conduit 40 is stopped. The valve closing timing is controlled so as to return to 14.

  When there is a request to fully close the flow rate adjusting valve, that is, when there is a request to stop EGR, the flow rate adjusting valves 38 and 44 are closed. The flow rate adjusting valves 38 and 44 are controlled to open and close corresponding to the required EGR amount. Therefore, when the EGR stop request is made and only the flow rate adjustment valve 44 is opened, the flow rate adjustment valve 44 is closed and the flow rate adjustment valve 38 is opened together with the flow rate adjustment valve 44. If so, both are closed.

  In the system of the present embodiment, when the flow rate adjustment valve 38 is opened together with the flow rate adjustment valve 44, the closing timing of the flow rate adjustment valve 38 is set to be higher than the closing timing of the flow rate adjustment valve 44. Slow down. By doing so, the reformed gas can be recirculated to the intake passage 14 until a later time, in other words, the reformed gas can be prevented from remaining in the reformed gas conduit 34, so that the reformed gas can be efficiently passed. Can be used.

[Specific Processing in Embodiment 4]
FIG. 9 is a flowchart of a routine executed by the ECU 50 in order to realize the above function. According to the routine shown in FIG. 9, it is first determined whether or not there is a request for fully closing the flow rate adjusting valve (step 520). If there is no full-close request, this routine is temporarily terminated.

  If there is a fully closed request, it is determined whether or not the flow rate adjustment valve 38 is being opened (step 540). That is, it is determined whether or not the flow rate adjusting valves 38 and 44 are both open. As described in the first embodiment, the flow rate adjustment valve 38 is controlled so as to compensate for the EGR amount that is insufficient only by the flow rate adjustment valve 44. Therefore, by determining whether or not the flow rate adjusting valve 38 is being opened, it is determined whether both the flow rate adjusting valves 38 and 44 are open.

  When it is determined that both the flow rate adjusting valves 38 and 44 are open, first, the flow rate adjusting valve 44 is fully closed (step 560), and then the flow rate adjusting valve 38 is fully closed (step 580). Subsequently, fuel injection to the heat exchanger 24 is prohibited (step 600). On the other hand, when it is determined that both the flow rate adjusting valves 38 and 44 are not opened, the flow rate adjusting valve 44 is fully closed (step 620), and this routine is ended.

  According to the routine of FIG. 9 described above, when the EGR stop request is made in a state where both the flow rate adjusting valves 38 and 44 are open, the valve closing timing of the flow rate adjusting valve 38 is set to the flow rate adjusting value. By making it later than the closing timing of the valve 44, the reformed gas recirculated from the flow rate adjusting valve 38 can be used efficiently.

  In the fourth embodiment described above, the “valve closing timing control means” according to the eighth aspect of the present invention is realized by executing the processing of steps 540 to 580 of FIG.

Embodiment 5 FIG.
In the present embodiment, in the configuration of FIG. 1, control is performed to delay the closing timing of the flow rate adjustment valve 38 from the closing timing of the flow rate adjustment valve 44 at the time of deceleration, and the opening degree of the flow rate adjustment valve 38. It is characterized by executing control to close the valve after increasing.

  FIG. 10 is a time chart for explaining the closing timings of the flow rate adjusting valves 38 and 44 and the accelerator (throttle valve) opening degree at the time of deceleration (accelerator off). FIG. 10A shows the opening degree of the flow rate adjustment valve 38, and FIG. 10B shows the opening degree of the flow rate adjustment valve 44. FIG.10 (c) shows the opening degree of an accelerator (throttle valve).

As shown in FIG. 10C, for example, at the time of deceleration (time T _a ), the accelerator is turned off. If the accelerator is turned off, EGR is also stopped. Therefore, as shown in FIG. 10B, first, the flow rate adjustment valve 44 is fully closed (time T _b ). As a result, EGR from the exhaust passage 22 on the downstream side of the heat exchanger 24 can be stopped early, and the amount of inert gas remaining in the intake passage 14 can be reduced. Here, t ₁ shown in FIG. 10B is a time corresponding to a delay time until the flow rate adjusting valve 44 is fully closed after the EGR stop request.

After the flow rate adjustment valve 44 is fully closed, as shown in FIG. 10A, the flow rate adjustment valve 38 is fully closed (time T _d ). Here, t ₅ shown in FIG. 10 (a), after the EGR stop request, the flow control valve 38 is a time corresponding to the delay time until the fully closed.

In the present embodiment, immediately before the flow rate adjustment valve 38 is fully closed, the opening degree of the flow rate adjustment valve 38 is increased (time T _c ). By doing so, the reformed gas recirculated from the flow rate adjustment valve 38 can be temporarily increased. As a result, more reformed gas can remain in the intake passage 14, so that the proportion of hydrogen gas present in the intake air can be increased. Therefore, it is possible to improve the response to the accelerator opening when the ignition timing is advanced and the accelerator is turned on next time.

Incidentally, t ₂ shown in FIG. 10 (a), the flow regulating valve 44 after the fully opened, it is time to increase the opening of flow control valve 38. Further, t ₃ shown in FIG. 10A is a time corresponding to the time until the opening degree of the flow rate adjustment valve 38 is increased after the EGR stop request, and is the sum of t ₁ and t ₂ described above. Is equal to the time. Further, t ₄ shown in FIG. 10A corresponds to a time during which the opening degree of the flow rate adjustment valve 38 is increased.

  In the above-described embodiment, after the flow rate adjustment valve 44 is fully closed, the opening amount of the flow rate adjustment valve 38 is temporarily increased to thereby increase the “first flow rate adjustment valve opening amount” according to the ninth aspect of the invention. "Correction means" is realized.

Embodiment 6 FIG.
In the system of this embodiment, in the configuration of FIG. 1, when there is a failure (failure) in the flow rate adjustment valve 44, the flow rate adjustment valve 38 is closed after increasing the supply amount of reforming fuel for a certain period of time. It is characterized by executing control.

  When a failure of the flow rate adjusting valve 44 is detected, it becomes impossible to control the amount of gas recirculated from the flow rate adjusting valve 44 to the intake passage 14. For this reason, when there is a failure of the flow rate adjustment valve 44, fail safe control is performed to fully close the flow rate adjustment valve 38. In this fail-safe control, the supply of reforming fuel to the heat exchanger 24 is prohibited after the flow rate adjustment valve 38 is fully closed. However, if the reforming fuel is not supplied, the fuel reforming is performed. The reforming reaction does not proceed on the catalyst.

  Here, the reforming reaction is an endothermic reaction, and it is known that the temperature of the reaction system, that is, the temperature of the fuel reforming catalyst decreases as the reforming reaction proceeds. That is, while the flow rate adjustment valve 38 is opened and the reformed gas is recirculated to the intake passage 14, not only the deterioration of combustion due to the reformed gas can be suppressed, but also the temperature increase of the fuel reforming catalyst can be prevented. However, when the fail-safe control is executed and the flow rate adjustment valve 38 is fully closed, the reforming fuel is not supplied, so that the above effect cannot be achieved and the temperature of the fuel reforming catalyst gradually increases. May lead to thermal degradation.

  Therefore, in the system of this embodiment, when fail-safe control is executed, control for increasing the supply amount of reforming fuel is executed for a certain period of time, and thereafter control for fully closing the flow rate adjustment valve 38 is executed. . By doing so, the endothermic reaction can be rapidly advanced during the fail-safe control, and it is possible to suppress the thermal deterioration accompanying the rise of the fuel reforming catalyst. When a failure is detected, it is desirable to notify the outside of the vehicle, for example, a vehicle driver, at the same time as performing the fail-safe control.

[Specific Processing in Embodiment 6]
FIG. 11 is a flowchart of a routine executed by the ECU 50 in order to realize the above function. According to the routine shown in FIG. 11, it is first determined whether or not the flow rate adjustment valve 38 is open (step 640). As described in the first embodiment, the flow rate adjustment valve 38 is controlled so as to compensate for the EGR amount that is insufficient only by the flow rate adjustment valve 44. Therefore, if it is determined whether or not the flow rate adjustment valve 38 is open, it is possible to determine whether or not a control command has been issued to the flow rate adjustment valve 44 and to determine whether or not the flow rate adjustment valve 44 has failed. It is determined whether or not the precondition is satisfied. If it is determined that there is no precondition for determining a failure, this routine is temporarily terminated.

  If it is determined that the precondition for determining the failure of the flow rate adjusting valve 44 is satisfied, it is determined whether or not the flow rate adjusting valve 44 is failed (step 660). If it is determined that the flow rate adjusting valve 44 is in failure, the fuel injection amount to the heat exchanger 24 is increased (step 680), then the flow rate adjusting valve 38 is fully closed (step 700), and further continued. Thus, fuel injection to the heat exchanger 24 is prohibited (step 720). On the other hand, when it is determined that the flow rate adjustment valve 44 is not a failure, this routine is terminated.

  According to the routine of FIG. 11 described above, since the fuel injection amount to the heat exchanger 24 is increased when a failure of the flow rate adjustment valve 44 occurs, the thermal deterioration of the fuel reforming catalyst is suppressed. be able to.

  In the above-described sixth embodiment, the “failure detecting means” in the tenth aspect of the invention by executing the process of step 660 of FIG. 11 causes the “failure detection means” in the tenth invention to execute the process of step 680 of FIG. The “supply amount control means” in the tenth invention is realized.

It is a figure for demonstrating the system configuration | structure of Embodiment 1 of this invention. 2 is a diagram for explaining a mechanism for controlling two exhaust gas recirculations in accordance with an operating state of the internal combustion engine 10. FIG. It is a figure for demonstrating operation | movement of the flow regulating valves 38 and 44 at the time of controlling two EGR mentioned above according to the request | required EGR amount. 4 is a flowchart of a routine that is executed by the ECU 50 according to the first embodiment. FIG. 6 is a diagram for illustrating a system configuration of a modified example of the first embodiment. 6 is a flowchart of a routine that is executed by the ECU 50 according to the second embodiment. It is a figure for demonstrating operation | movement of the flow regulating valves 38 and 44 in case knocking is detected. 10 is a flowchart of a routine that is executed by an ECU 50 according to the third embodiment. It is a flowchart of the routine which ECU50 of Embodiment 4 performs. It is a time chart for demonstrating the valve closing timing of the flow regulating valves 38 and 44 of Embodiment 5, and an accelerator opening. 14 is a flowchart of a routine that is executed by the ECU 50 according to the sixth embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Internal combustion engine 14 Intake passage 22 Exhaust passage 24 Heat exchanger 32 Reforming fuel supply device 34 Reformed gas conduit 38 Flow control valve 40 Exhaust gas conduit 44 Flow control valve 50 ECU
52 Crank angle sensor 54 In-cylinder pressure sensor

Claims (10)

A reformed gas generating means disposed in an exhaust passage of the internal combustion engine and capable of generating a reformed gas containing hydrogen gas from a part of the exhaust gas flowing through the exhaust passage and the reforming fuel;
A reformed gas recirculation passage connected to the reformed gas generating means for recirculating the reformed gas to an intake passage of the internal combustion engine;
An exhaust gas recirculation passage for recirculating a part of the exhaust gas in the exhaust passage downstream of the reformed gas generating means to the intake passage;
An internal combustion engine with a fuel reforming system. A first flow rate adjusting valve that adjusts the flow rate of the gas that flows back to the intake passage through the reformed gas recirculation passage;
A second flow rate adjusting valve that adjusts the flow rate of the gas that flows back to the intake passage through the exhaust gas recirculation passage;
When there is an exhaust gas recirculation request for the intake passage, the timing of exhaust gas recirculation by the first flow rate adjustment valve is slower than the timing of exhaust gas recirculation by the second flow rate adjustment valve, Valve opening timing control means for controlling the valve opening timing of the second flow rate adjusting valve;
The internal combustion engine with a fuel reforming system according to claim 1. A first flow rate adjusting valve that adjusts the flow rate of the gas that flows back to the intake passage through the reformed gas recirculation passage;
A second flow rate adjusting valve that adjusts the flow rate of the gas that flows back to the intake passage through the exhaust gas recirculation passage;
Required exhaust gas recirculation amount acquisition means for acquiring the required exhaust gas recirculation amount;
Opening degree control means for controlling the opening degree of the first flow rate adjustment valve and the second flow rate adjustment valve according to the required exhaust gas recirculation amount,
The opening degree control means includes valve opening permission means for permitting opening of the first flow rate adjustment valve when the required exhaust gas recirculation amount cannot be achieved even when the opening degree of the second flow rate adjustment valve is fully opened. The internal combustion engine with a fuel reforming system according to claim 1 or 2. A reforming fuel supply means for supplying the reforming fuel to the reformed gas generating means;
Reforming condition determining means for determining whether or not the reformed gas generating means is in a predetermined condition capable of generating the reformed gas,
The fuel reforming system according to claim 3, wherein the reforming fuel supply unit includes a supply prohibiting unit that prohibits the supply of the reforming fuel when it is determined that the predetermined condition is not satisfied. Internal combustion engine. A first flow rate adjusting valve that adjusts the flow rate of the gas that flows back to the intake passage through the reformed gas recirculation passage;
A second flow rate adjusting valve that adjusts the flow rate of the gas that flows back to the intake passage through the exhaust gas recirculation passage;
Torque fluctuation detecting means for detecting fluctuations in torque of the internal combustion engine;
Torque fluctuation determination means for determining whether or not the torque fluctuation exceeds a predetermined value;
When the fluctuation of the torque exceeds a predetermined value, the flow rate of the gas that flows back to the intake passage through the exhaust gas recirculation passage is reduced, and the reformed gas that flows back to the intake passage through the reformed gas recirculation passage Opening correction means for correcting the opening of the first flow rate adjustment valve and the second flow rate adjustment valve so as to increase the flow rate of
The internal combustion engine with a fuel reforming system according to any one of claims 1 to 4, further comprising: A first flow rate adjusting valve that adjusts the flow rate of the gas that flows back to the intake passage through the reformed gas recirculation passage;
A second flow rate adjusting valve that adjusts the flow rate of the gas that flows back to the intake passage through the exhaust gas recirculation passage;
Knocking detection means for detecting occurrence of knocking in the internal combustion engine;
When knocking occurs, the flow rate of the gas returning to the intake passage through the exhaust gas recirculation passage is decreased, and the flow rate of the reformed gas returning to the intake passage through the reformed gas recirculation passage is increased. Opening correction second means for correcting the opening of the first flow rate adjustment valve and the second flow rate adjustment valve;
The internal combustion engine with a fuel reforming system according to claim 1, comprising: Ignition timing retard control means for controlling the ignition timing to the retard side when knocking occurs,
Correctable determination means for determining whether or not the opening correction second means is executable,
The ignition timing retardation control means reduces the ignition timing retardation amount when the opening correction second means is executable compared to when it is not executable. An internal combustion engine with a fuel reforming system. A first flow rate adjusting valve that adjusts the flow rate of the gas that flows back to the intake passage through the reformed gas recirculation passage;
A second flow rate adjustment valve that adjusts the flow rate of the gas that flows back to the intake passage through the exhaust gas recirculation passage,
When there is a request to stop exhaust gas recirculation for the intake passage, the first flow rate is set so that the exhaust gas recirculation stop timing by the first flow rate adjustment valve is later than the exhaust recirculation stop timing by the second flow rate adjustment valve. The internal combustion engine with a fuel reforming system according to any one of claims 1 to 7, further comprising: a valve closing timing control unit that controls a valve closing timing of the adjusting valve and the second flow rate adjusting valve.   When the stop request is at the time of deceleration of the internal combustion engine, the first flow rate adjustment valve is opened so as to temporarily increase the flow rate of the reformed gas that flows back to the intake passage through the reformed gas recirculation passage. The internal combustion engine with a fuel reforming system according to claim 8, further comprising first flow rate adjusting valve opening correction means for correcting the degree. A first flow rate adjusting valve that adjusts the flow rate of the gas that flows back to the intake passage through the reformed gas recirculation passage;
A second flow rate adjusting valve that adjusts the flow rate of the gas that flows back to the intake passage through the exhaust gas recirculation passage;
A reforming fuel supply means for supplying the reforming fuel to the reformed gas generating means;
A failure detection means for detecting a failure of the second flow rate adjustment valve,
10. The reforming fuel supply unit includes a supply amount control unit that increases a supply amount of the reforming fuel when the failure is detected. An internal combustion engine with a fuel reforming system.

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