JP2013174135A - Control device of internal combustion engine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a control device of an internal combustion engine which can avoid the occurrence of preignition in a spark ignition internal combustion engine including an ignition plug.SOLUTION: A control device of an internal combustion engine includes; a fuel property detecting means for detecting content information of aniline based nitrogen compound in fuel supplied to the internal combustion engine 10; and a control means for controlling the temperature of a combustion chamber in the compression stroke of the internal combustion engine 10 to a range where preignition does not occur, based on the content information of aniline based nitrogen compound. It is preferable that when a NOx amount MNOx in an exhaust gas is larger than a prescribed determination value a (step 102) and establishment of a KCS (Knock Control System) amount of retard amount=0 is recognized (step 104), the control device determines that the aniline based nitrogen compound is contained in the fuel and an ignition timing in a high rotation speed high load region is retarded as a preignition preventing control (step 106).

Description

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

  Conventionally, for example, in WO 2011/114459, when a nitrogen component concentration in gasoline fuel supplied to an internal combustion engine is high, a part or all of an operation region where lean burn operation is performed is changed to a region where stoichiometric operation is performed. A control device is disclosed. When lean burn operation is performed with supply of gasoline fuel having a high nitrogen component concentration, the amount of NOx emissions increases. In the above prior art, the nitrogen component concentration in the fuel is detected by the fuel property detection device, and when the detected nitrogen component concentration is higher than a predetermined value, the lean burn operation region is reduced in advance, so the amount of NOx emissions Can be suppressed.

WO2011 / 114459 gazette JP 2009-503526 A JP 2011-12624 A JP 2010-513605 A

  By the way, recent high-octane gasoline fuel may contain an aniline-based nitrogen compound which is a kind of nitrogen component. Aniline-based nitrogen compounds are known not to cause a low-temperature oxidation reaction because an intermediate product is very stable. For this reason, the higher the component concentration of the aniline-based nitrogen compound, the higher the octane number (RON), which is an index of knocking, and the higher the anti-knocking performance.

  However, as a result of the present inventors' extensive research, it has been found that preignition (pre-ignition) is likely to occur when the concentration of the aniline nitrogen compound is high. Here, pre-ignition is a phenomenon in which the air-fuel mixture is self-ignited from an overheated portion in the combustion chamber before the normal ignition timing of the spark plug during the compression stroke in the combustion cycle. When pre-ignition occurs, the air-fuel mixture is burned while being compressed, so the pressure and temperature in the combustion chamber may become abnormally high. For this reason, in an internal combustion engine that uses gasoline fuel with a high octane number to improve knocking resistance, it may be assumed that the concentration of the aniline nitrogen compound component is high, and in this case, unexpected preignition may occur. there were.

  The present invention has been made to solve the above-described problems, and provides a control device for an internal combustion engine capable of avoiding the occurrence of pre-ignition in a spark ignition internal combustion engine having a spark plug. For the purpose.

In order to achieve the above object, a first invention is a control device for a spark ignition type internal combustion engine including a spark plug,
A fuel property detecting means for detecting content information of the aniline nitrogen compound in the fuel supplied to the internal combustion engine;
Control means for controlling the temperature in the combustion chamber during the compression stroke of the internal combustion engine to a range where pre-ignition does not occur based on the content information of the aniline-based nitrogen compound;
It is characterized by having.

According to a second invention, in the first invention,
The fuel property detection means includes
NOx amount detection means for detecting the NOx amount of gas discharged from the internal combustion engine;
Octane number information acquisition means for acquiring octane number information in the fuel;
And the content information of the aniline-based nitrogen compound is detected based on the relationship between the NOx amount and the octane number information.

According to a third invention, in the first or second invention,
A knock control means for suppressing the occurrence of knocking by learning the ignition timing of the internal combustion engine while checking the occurrence of knocking of the internal combustion engine;
The octane number information acquisition means acquires the learned value of the ignition timing by the knock control means as the octane number information.

A fourth invention is any one of the first to third inventions,
Further comprising ignition timing control means for controlling the ignition timing of the internal combustion engine;
The control means is characterized in that when the aniline-based nitrogen compound is contained in the fuel, the ignition timing in a predetermined high-rotation and high-load region is retarded from the normal time.

According to a fifth invention, in any one of the first to fourth inventions,
A compression ratio variable means for variably setting the compression ratio of the internal combustion engine;
The control means is characterized in that when the aniline nitrogen compound is contained in the fuel, the compression ratio in a predetermined high rotation and high load region is set lower than normal.

According to a sixth invention, in the fifth invention,
The compression ratio variable means includes means for variably setting the closing timing of the intake valve,
The control means is characterized in that when the aniline-based nitrogen compound is contained in the fuel, the closing timing of the intake valve in a predetermined high rotation high load region is delayed from the normal time.

A seventh invention is the invention according to any one of the first to sixth inventions,
In an internal combustion engine with a supercharger,
Means for variably setting the upper limit value of the supercharging pressure;
The control means is characterized in that when the aniline nitrogen compound is contained in the fuel, the limit value is set lower than normal.

According to an eighth invention, in any one of the first to seventh inventions,
In the hybrid vehicle having the internal combustion engine and the electric motor, and driving the vehicle by the driving force of the internal combustion engine and / or the electric motor,
Means for variably setting output distribution between the internal combustion engine and the electric motor;
The control means is characterized in that when the aniline-based nitrogen compound is contained in the fuel, the output distribution of the electric motor to the internal combustion engine in a predetermined high-rotation high-load region is increased as compared with normal time. .

According to a ninth invention, in any one of the first to eighth inventions,
A determination means for determining that fuel has been supplied to the fuel tank of the internal combustion engine;
The fuel property detecting means detects content information of an aniline nitrogen compound in the fuel supplied to the internal combustion engine when it is determined that fuel is supplied to the fuel tank.

  According to the first aspect of the invention, information on the content of the aniline nitrogen compound in the fuel supplied to the internal combustion engine is detected. Based on the content information of the aniline-based nitrogen compound, the temperature of the combustion chamber during the compression stroke of the internal combustion engine is controlled to be in a range where pre-ignition does not occur. When the aniline nitrogen compound is contained in the fuel, the pre-ignition generation temperature is lowered. For this reason, according to this invention, generation | occurrence | production of preignition can be avoided effectively using the content information of an aniline-type nitrogen compound.

  According to the second invention, the amount of NOx in the exhaust gas discharged from the internal combustion engine has a correlation with the concentration of nitrogen compound in the fuel. Here, the nitrogen compound concentration in the fuel varies depending on the component concentrations of the aniline nitrogen compound and the nitro nitrogen compound. On the other hand, the octane number in the fuel changes mainly according to the component concentration of the aniline nitrogen compound and does not change greatly according to the component concentration of the nitro nitrogen compound. For this reason, according to the present invention, it is possible to detect the content information of the aniline-based nitrogen compound based on the relationship between the NOx amount in the exhaust gas and the octane number information.

  According to the third aspect of the invention, the learned value of the ignition timing calculated by the knock control means is a value reflecting the steady anti-knocking performance, and is therefore strongly related to the octane number in the fuel. For this reason, according to the present invention, the learned value of the ignition timing can be used as the octane number information in the fuel.

  According to the fourth invention, when the aniline-based nitrogen compound is contained in the fuel, the ignition timing is retarded as compared with the normal time in a predetermined high rotation and high load operation region. For this reason, according to the present invention, when the pre-ignition generation temperature is lowered, the temperature increase in the combustion chamber in the high-rotation and high-load region where the combustion temperature increases can be suppressed. It can be effectively avoided.

  According to the fifth aspect of the invention, when the aniline-based nitrogen compound is contained in the fuel, the compression ratio in the predetermined high-rotation and high-load operation region is set lower than that in the normal time. For this reason, according to the present invention, when the pre-ignition occurrence temperature is lowered, the temperature rise in the combustion chamber can be suppressed, so that the occurrence of pre-ignition can be effectively avoided.

  According to the sixth aspect of the present invention, when the aniline-based nitrogen compound is contained in the fuel, the closing timing (IVC) of the intake valve in the predetermined high rotation high load region is retarded as compared with the normal time. For this reason, according to the present invention, when the pre-ignition occurrence temperature is lowered, the actual compression ratio can be lowered, so that the occurrence of pre-ignition can be effectively avoided.

  According to the seventh invention, when the aniline nitrogen compound is contained in the fuel, the upper limit value of the supercharging pressure is set to a lower value than in the normal time. For this reason, according to the present invention, when the pre-ignition occurrence temperature is lowered, the upper limit of the supercharging pressure can be lowered, so that the occurrence of pre-ignition can be effectively avoided.

  According to the eighth invention, when the aniline-based nitrogen compound is contained in the fuel, the output distribution of the electric motor to the internal combustion engine in the predetermined high rotation high load region is increased as compared with the normal time. For this reason, according to the present invention, when the pre-ignition occurrence temperature is lowered, the temperature rise in the combustion chamber can be suppressed, so that the occurrence of pre-ignition can be effectively avoided.

  According to the ninth aspect, when it is determined that the fuel is supplied, the content information of the combustion aniline-based nitrogen compound is detected. Therefore, according to the present invention, since concentration detection is performed at the timing when the properties of the fuel supplied to the internal combustion engine change, the content information of the aniline nitrogen compound in the fuel supplied to the internal combustion engine is always accurately grasped. can do.

It is a figure for demonstrating the system configuration | structure of Embodiment 1 of this invention. It is a figure for demonstrating the characteristic of the aniline type nitrogen compound in gasoline fuel. It is a figure for demonstrating the ignition timing with respect to the driving | operation area | region of an internal combustion engine. It is a flowchart of the routine performed in Embodiment 1 of the present invention.

  Embodiments of the present invention will be described below with reference to the drawings. In addition, the same code | symbol is attached | subjected to the element which is common in each figure, and the overlapping description is abbreviate | omitted. The present invention is not limited to the following embodiments.

Embodiment 1 FIG.
[Configuration of Embodiment 1]
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 (engine) 10. The internal combustion engine 10 is configured as a spark ignition internal combustion engine with a supercharger. In addition, since the structure of a supercharger is well-known in many literatures, illustration is abbreviate | omitted. An exhaust passage 16 communicates with the exhaust side of the internal combustion engine 10. An exhaust purification catalyst 18 for purifying harmful components in the exhaust gas is disposed in the exhaust passage 16. As the exhaust purification catalyst 18, for example, a known catalyst such as a three-way catalyst can be used.

  In addition, the system according to the present embodiment includes a fuel tank 12 for storing refueled gasoline fuel. One end of a fuel pipe 14 is connected to the fuel tank 12. The other end of the fuel pipe 14 is connected to the fuel system of the internal combustion engine 10.

  Further, on the upstream side of the exhaust purification catalyst 18 in the exhaust passage 16, a NOx sensor 22 for detecting the amount of NOx in the exhaust gas is provided as an exhaust analyzer for analyzing the components of the gas exhausted from the internal combustion engine 10. It has been.

  The system of the present embodiment includes an ECU (Electronic Control Unit) 20 as shown in FIG. In addition to the NOx sensor 22 described above, the input unit of the ECU 20 includes a crank angle sensor for detecting the rotational position of the crankshaft, a water temperature sensor for detecting the water temperature, and a knock sensor for detecting the occurrence of knocking. Sensor is connected. Various actuators such as a throttle valve, a spark plug, and a fuel injection valve are connected to the output portion of the ECU 20. The ECU 20 controls the operating state of the internal combustion engine 10 based on various types of input information.

[Operation of Embodiment 1]
Next, the operation of the present embodiment will be described with reference to FIGS. In the internal combustion engine 10, during the compression stroke in the combustion cycle, preignition may occur in which the air-fuel mixture self-ignites from an overheated portion in the combustion chamber before the normal ignition timing of the spark plug. When pre-ignition occurs, the air-fuel mixture burns while being compressed, so the pressure and temperature in the combustion chamber may become abnormally high. In particular, in recent years, there has been an increasing demand for supercharged engines and high compression ratio engines in order to ensure high output with small displacement, but these high compression ratio engines have a high pres- Is more likely to occur.

  In order to suppress the occurrence of pre-ignition, the temperature in the combustion chamber during the compression stroke may be controlled to be lower than the temperature at which the pre-ignition occurs. However, the pre-ignition generation temperature varies in a complicated manner depending on the compression ratio of the internal combustion engine 10 and the fuel properties of the supplied gasoline fuel. Accordingly, the inventors of the present application have made extensive studies focusing on the relationship between the occurrence of pre-ignition and fuel properties. As a result, the inventors of the present application have found that the pre-ignition generation temperature varies depending on the component concentration of the aniline nitrogen compound contained in the gasoline fuel.

  FIG. 2 is a diagram for explaining the characteristics of aniline-based nitrogen compounds in gasoline fuel. In the figure, (A) shows the relationship between the aniline nitrogen compound component concentration and the octane number (RON), and (B) shows the relationship between the aniline nitrogen compound component concentration and the pre-ignition temperature. ing.

  First, as shown in FIG. 2A, the aniline-based nitrogen compound of gasoline fuel has a higher octane number (RON) that is an index of knocking as the component concentration is higher. This is because an intermediate product of aniline-based nitrogen compound is very stable, so that a dominant low-temperature oxidation reaction hardly occurs in a temperature-pressure region where knocking occurs. For this reason, it can be said that the high octane fuel containing the aniline-based nitrogen compound is very effective from the viewpoint of improving the knocking resistance.

  However, according to the knowledge of the inventors of the present application, as shown in FIG. 2B, the pre-ignition generation temperature of the aniline-based nitrogen compound decreases as the component concentration increases. This is presumably because preignition is a very high temperature pyrolysis reaction unlike knocking. For this reason, when an aniline nitrogen compound comes into contact with a high temperature substance, it decomposes into an amide group and a benzene ring, and a catalytic action between the amide group and a high temperature metal substance (for example, a spark plug or a valve) occurs in the combustion chamber. , Sporadic pre-ignition occurs.

  It is also assumed that aniline-based nitrogen compounds are contained in large amounts in gasoline additives such as high-octane fuels and octane number improvers. When gasoline fuel having a high component concentration of such an aniline-based nitrogen compound is supplied, the pre-ignition generation temperature of the internal combustion engine is remarkably lowered, and unexpected pre-ignition may occur.

  Therefore, in the system of the present embodiment, based on the content information of the aniline nitrogen compound in the gasoline fuel, the temperature in the combustion chamber during the compression stroke is a temperature range in which preignition does not occur, specifically, aniline nitrogen. The following control is performed so that the temperature range does not reach the pre-ignition generation temperature corresponding to the compound content (component concentration). In this control, when it is determined that the aniline-based nitrogen compound is contained in the gasoline fuel, it is determined that the risk of occurrence of pre-ignition is high, and pre-ignition avoidance control is executed. More specifically, first, the NOx amount (NOx concentration) in the gas exhausted from the internal combustion engine 10 is detected using the NOx sensor 22. The amount of NOx in the exhaust gas changes according to the concentration of the nitrogen compound component in the gasoline fuel. Therefore, for example, by determining whether or not the detected NOx amount is larger than a predetermined reference value, the component concentration of the nitrogen compound in the fuel supplied to the internal combustion engine 10 is higher than a predetermined reference concentration. Whether it is high or not can be determined.

  However, as a nitrogen compound judged using the NOx sensor 22, not only an aniline nitrogen compound but also a nitro nitrogen compound can be considered. For this reason, it cannot be said that the aniline-type nitrogen compound is contained in the fuel only because the concentration of the nitrogen compound component in the fuel is high. Therefore, in the system of the present embodiment, the octane number in the fuel is used as means for discriminating between aniline nitrogen compounds and nitro nitrogen compounds. That is, as described above, the octane number in the fuel increases as the component concentration of the aniline nitrogen compound increases. In contrast, nitro-based nitrogen compounds do not have a correlation as seen with aniline-based nitrogen compounds between the component concentration and the octane number. For this reason, it is possible to detect the content information of the aniline nitrogen compound in the fuel by detecting the octane number (or the correlation value) in the fuel and using the above-described nitrogen compound component concentration and the octane number. Become.

  As a method for detecting the octane number, for example, a method using a learning value of the ignition timing by a knock control system (KCS) is conceivable. That is, the KCS learns the ignition timing retardation amount that can avoid knocking according to the occurrence of knocking. Therefore, the learned retardation amount (KCS retardation amount) can be determined as a value reflecting the anti-knocking performance, that is, the octane number of the fuel. Therefore, when the KSC retardation amount is smaller than a predetermined reference value (for example, KCS retardation amount = 0), it is determined that the anti-knocking performance is high and the octane number in the fuel is higher than a certain reference. it can. In this way, the content (for example, component concentration) of the aniline-based nitrogen compound in the fuel can be determined by using the component concentration of the nitrogen compound and the KSC retardation amount.

  As the preignition avoidance control, for example, when it is determined that an aniline nitrogen compound is contained in gasoline fuel, control for retarding the ignition timing of the internal combustion engine 10 can be considered. FIG. 3 is a diagram for explaining the ignition timing for the operating region of the internal combustion engine. As shown in this figure, when it is determined that the aniline nitrogen compound is contained in the gasoline fuel, the ignition timing is retarded in a predetermined high rotation high load region where the combustion chamber temperature becomes high. . The ignition timing retardation amount may be set to a predetermined fixed value, or may be set so that the retardation amount increases as the component concentration of the aniline nitrogen compound increases. These settings can be realized, for example, by creating map data in which the relationship between the component concentration of the aniline-based nitrogen compound and the ignition timing retard amount is converted into data, and storing this map data in the ECU 20. . As a result, the combustion chamber temperature during the compression stroke of the internal combustion engine 10 can be reduced in the operating region where pre-ignition is likely to occur, so that the occurrence of pre-ignition can be effectively avoided.

  Moreover, the component concentration of the aniline nitrogen compound in gasoline fuel changes mainly after the fuel is supplied. Therefore, the timing of detecting the fuel property is preferably the timing at which gasoline fuel is supplied. Thereby, when the component concentration of the aniline nitrogen compound changes, the component concentration of the aniline nitrogen compound after the change can be detected quickly.

[Specific Processing in Embodiment 1]
Next, with reference to FIG. 4, the specific content of the process performed in this Embodiment is demonstrated. FIG. 4 is a flowchart of a routine executed by the ECU 20. In the routine shown in FIG. 4, it is first determined whether or not gasoline fuel has been supplied into the fuel tank 12 (step 100). The presence / absence of fuel supply can be determined by detecting the opening / closing of the fuel cap or detecting a change in the remaining amount of fuel. As a result, when it is determined that the fuel is not refueled, it is determined that the fuel property in the fuel tank 12 has not changed, and this routine is immediately terminated.

  On the other hand, if it is determined in step 100 that the fuel has been refueled, it is determined that the fuel property in the fuel tank 12 may have changed, the process proceeds to the next step, and the exhaust gas from the internal combustion engine 10 is exhausted. It is determined whether or not the NOx amount MNOx of the gas to be performed is larger than a predetermined determination value a (step 102). Specifically, the NOx amount MNOx of the exhaust gas is detected based on the output signal of the NOx sensor 22. The predetermined determination value a is a determination value for determining that the component concentration of the nitrogen compound contained in the fuel is higher than a predetermined reference value, and a predetermined value is read. As a result, when the establishment of MNOx> a is not recognized, it is determined that the component concentration of the aniline nitrogen compound is low because the component concentration of the nitrogen compound in the fuel is low, and this routine is immediately terminated. .

  On the other hand, when the formation of MNOx> a is recognized in step 102, it is determined that the component concentration of the aniline-based nitrogen compound may be high because the component concentration of the nitrogen compound in the fuel is high. The process proceeds to the next step, and it is determined whether or not the KCS retardation amount = 0 (step 104). As a result, when the establishment of KCS retardation amount = 0 is not recognized, it can be determined that the knocking resistance is low, that is, the octane number in the fuel is low. In this case, it is determined that the nitrogen compound in the fuel is mainly composed of nitro and the concentration ratio of the aniline component is low, and this routine is immediately terminated.

  On the other hand, when the establishment of KCS retardation amount = 0 is confirmed in step 104, it can be determined that the anti-knocking performance is high, that is, the octane number in the fuel is high. In this case, since it can be determined that the component concentration of the aniline-based nitrogen compound is high, the process proceeds to the next step, and preignition avoidance control is executed (step 106). Here, specifically, the ignition timing is set to be retarded from the normal time in a predetermined high rotation high load region where the combustion chamber temperature becomes high.

  As described above, according to the system of the present embodiment, when the aniline-based nitrogen compound is contained in the fuel, the ignition timing is a value that is retarded from the normal time in the high rotation and high load operation region. Then, the internal combustion engine 10 is operated. Thereby, even if it is a case where the fuel with which the aniline type nitrogen compound was mixed is used, generation | occurrence | production of preignition can be avoided effectively.

  By the way, in the first embodiment described above, it is determined whether or not the component concentration of the aniline nitrogen compound is high based on the nitrogen compound content information determined from the NOx amount in the exhaust gas and the octane number determined from the KCS learning value. However, this is not the only information that can be detected as information on the content of aniline nitrogen compounds. That is, for example, by creating map data in which the relationship between the NOx amount in the exhaust gas and the KCS learning value and the component concentration of the corresponding aniline nitrogen compound is created, this map data is stored in the ECU 20. The component concentration of the aniline nitrogen compound may be detected. In this case, the preignition avoidance control may be executed when the component concentration of the aniline-based nitrogen compound in the fuel is higher than a predetermined determination concentration.

  In the first embodiment described above, the NOx amount in the exhaust gas is detected using the NOx sensor 22, but as another method, for example, the NOx amount is detected using an optical analyzer or the like. May be. In the first embodiment described above, the octane number is estimated using the KCS retardation amount. As another method, for example, an in-cylinder pressure sensor (for detecting the in-cylinder pressure of the internal combustion engine 10) ( In the apparatus having CPS), the octane number may be estimated using the in-cylinder pressure waveform of the combustion cycle detected by CPS.

  Further, in the first embodiment described above, as one aspect of the pre-ignition avoidance control, the ignition timing in the high-rotation and high-load operation region has been retarded. Not limited. That is, in the operation region where pre-ignition occurs, other control as described below may be executed as long as the combustion chamber temperature during the compression stroke of the internal combustion engine 10 can be reduced.

  That is, as another aspect of pre-ignition avoidance control, for example, in an internal combustion engine in which the compression ratio can be variably set, when it is determined that aniline-based nitrogen compounds are contained in gasoline fuel, the compression ratio is normally set. It may be set lower than that of time. As a means for lowering the compression ratio, for example, a method of using a variable compression ratio engine as an internal combustion engine or an internal combustion engine capable of varying the intake valve timing is used to retard (slowly close) the intake valve closing timing (IVC). Thus, a method of reducing the actual compression ratio can be considered. The compression ratio may be set to a predetermined low compression ratio, or may be set such that the higher the component concentration of the aniline nitrogen compound, the lower the compression ratio. In particular, in the case of a variable compression ratio (VCR) engine, it is preferable that the compression ratio at the time of high load is set low and the high compression ratio region is not expanded to the high load region. These settings are made, for example, by creating map data in which the relationship between the component concentration of the aniline-based nitrogen compound and the compression ratio or the retard amount of IVC corresponding to the compression ratio is created, and this map data is stored in the ECU 20 It can be realized by letting it go. Thereby, since the combustion chamber temperature during the compression stroke of the internal combustion engine 10 can be reduced, the occurrence of pre-ignition can be effectively suppressed.

  Further, as another aspect of the pre-ignition avoidance control, for example, when it is determined that an aniline-based nitrogen compound is contained in gasoline fuel, the upper limit value of the supercharging pressure is set to a predetermined value lower than a normal set value. It may be changed to an allowable value. Thereby, since the supercharging pressure at the time of high supercharging can be effectively limited, the temperature rise around the spark plug can be effectively suppressed in the operation region where pre-ignition is likely to occur. Thereby, generation | occurrence | production of preignition can be suppressed effectively.

  In addition, it is preferable to specify beforehand the allowable value of the supercharging pressure when the component concentration of the aniline-based nitrogen compound is high by experiments or the like. More specifically, the allowable value of the supercharging pressure (upper limit value) that can prevent the occurrence of pre-ignition when engine combustion is performed using gasoline fuel having a higher concentration of aniline-based nitrogen compounds than the specified value. Is obtained in advance through experiments or the like and stored in the ECU 20. Thereby, even when a fuel having a high component concentration of the aniline-based nitrogen compound is used, the occurrence of pre-ignition can be effectively suppressed.

  Further, the allowable value of the supercharging pressure upper limit value may be set such that the higher the component concentration of the aniline-based nitrogen compound in the gasoline fuel, the lower the allowable value. These settings can be realized, for example, by creating map data in which the relationship between the component concentration of the aniline-based nitrogen compound and the allowable value is converted into data, and storing this map data in the ECU 20 in advance. According to such a configuration, it is possible to optimize the upper limit value of the supercharging pressure according to the component concentration of the aniline-based nitrogen compound.

  Further, as another aspect of the pre-ignition avoidance control, for example, in a hybrid vehicle including an internal combustion engine and an electric motor, when it is determined that aniline-based nitrogen compound is contained in gasoline fuel, output distribution of the internal combustion engine May be reduced to increase the output distribution of the motor. The output distribution may be set to a predetermined output distribution (fixed value), or may be set so that the output distribution of the motor increases as the component concentration of the aniline nitrogen compound increases. These settings can be realized, for example, by creating map data in which the relationship between the component concentration of the aniline-based nitrogen compound and the output distribution is converted into data, and storing this map data in the ECU 20. Thereby, since the combustion chamber temperature during the compression stroke of the internal combustion engine 10 can be reduced, the occurrence of pre-ignition can be effectively suppressed.

  In the first embodiment described above, the ECU 20 executes the processing of steps 100 and 102 so that the “fuel property detecting means” in the first invention executes the processing of step 106. Thus, the “control means” in the first invention is realized.

  In the first embodiment described above, the ECU 20 executes the process of step 102, so that the “NOx amount detecting means” in the second invention executes the process of step 104. The “octane number information acquisition means” in the second invention is realized.

  In the first embodiment described above, the “determination means” according to the ninth aspect of the present invention is implemented when the ECU 20 executes the process of step 100 described above.

DESCRIPTION OF SYMBOLS 10 Internal combustion engine 12 Fuel tank 14 Fuel piping 16 Exhaust passage 18 Exhaust purification catalyst 20 ECU (Electronic Control Unit)
22 NOx sensor

Claims (9)

A spark ignition type internal combustion engine control device including a spark plug,
A fuel property detecting means for detecting content information of the aniline nitrogen compound in the fuel supplied to the internal combustion engine;
Control means for controlling the temperature in the combustion chamber during the compression stroke of the internal combustion engine to a range where pre-ignition does not occur based on the content information of the aniline-based nitrogen compound;
A control device for an internal combustion engine, comprising: The fuel property detection means includes
NOx amount detection means for detecting the NOx amount of gas discharged from the internal combustion engine;
Octane number information acquisition means for acquiring octane number information in the fuel;
2. The control device for an internal combustion engine according to claim 1, wherein content information of the aniline-based nitrogen compound is detected based on a relationship between the NOx amount and the octane number information. A knock control means for suppressing the occurrence of knocking by learning the ignition timing of the internal combustion engine while checking the occurrence of knocking of the internal combustion engine;
3. The control apparatus for an internal combustion engine according to claim 1, wherein the octane number information acquisition unit acquires a learned value of the ignition timing by the knock control unit as the octane number information. Further comprising ignition timing control means for controlling the ignition timing of the internal combustion engine;
4. The control device according to claim 1, wherein when the aniline nitrogen compound is contained in the fuel, the ignition timing is retarded from a normal time in a predetermined high rotation high load region. The control device for an internal combustion engine according to any one of the preceding claims. A compression ratio variable means for variably setting the compression ratio of the internal combustion engine;
5. The control device according to claim 1, wherein when the aniline nitrogen compound is contained in the fuel, the compression ratio in a predetermined high rotation and high load region is set lower than normal. The control device for an internal combustion engine according to any one of the preceding claims. The compression ratio variable means includes means for variably setting the closing timing of the intake valve,
The control means, when the aniline-based nitrogen compound is contained in the fuel, delays the closing timing of the intake valve in a predetermined high rotation high load region from the normal time. The control apparatus for an internal combustion engine according to any one of claims 5 to 6. In an internal combustion engine with a supercharger,
Means for variably setting the upper limit value of the supercharging pressure;
The internal combustion engine according to any one of claims 1 to 6, wherein the control means sets the limit value lower than normal when the aniline-based nitrogen compound is contained in the fuel. Engine control device. In the hybrid vehicle having the internal combustion engine and the electric motor, and driving the vehicle by the driving force of the internal combustion engine and / or the electric motor,
Means for variably setting output distribution between the internal combustion engine and the electric motor;
When the aniline nitrogen compound is contained in the fuel, the control means increases the output distribution of the electric motor to the internal combustion engine in a predetermined high rotation and high load region as compared with a normal time. The control device for an internal combustion engine according to any one of claims 1 to 7. A determination means for determining that fuel has been supplied to the fuel tank of the internal combustion engine;
The fuel property detection means detects content information of an aniline nitrogen compound in fuel supplied to the internal combustion engine when it is determined that fuel is supplied to the fuel tank. Item 9. The control device for an internal combustion engine according to any one of Items 1 to 8.

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