JP5549250B2 - Control device for internal combustion engine - Google Patents

Description

  The present invention relates to a control device for an internal combustion engine, and more particularly to a control device for an internal combustion engine that can use a mixed fuel of alcohol and gasoline.

  There is known an internal combustion engine that can use a mixed fuel obtained by mixing alcohol such as ethanol or methanol with gasoline. FIG. 9 is a graph showing the relationship between the distillation ratio of E80 (80% ethanol mixed fuel) and E0 (100% gasoline) and the temperature. Since gasoline is composed of multiple components and contains low boiling components, it has excellent vaporization characteristics even at low temperatures. On the other hand, since alcohol is a single component, its boiling point is determined and its boiling point is high (about 78 ° C. in the case of ethanol). For this reason, as can be seen from FIG. 9, a mixed fuel having a high alcohol concentration, such as E80, has a drawback that it is extremely difficult to vaporize at a temperature lower than the boiling point of the alcohol.

  Japanese Patent Application Laid-Open No. 2007-332936 discloses an apparatus for suppressing malfunction of a spark plug due to fuel adhesion in an internal combustion engine that can use such a mixed fuel. More specifically, this device includes a port injection valve that injects fuel into the intake port, and if it is determined that the fuel used is difficult to vaporize when the internal combustion engine is started, the ratio of intake asynchronous injection Is going to be reduced. In the intake asynchronous injection, the fuel is injected with the intake valve closed, so that the injected fuel is temporarily held in the intake port. For this reason, when the injected fuel is a fuel that is difficult to vaporize, that is, a fuel with a high alcohol concentration, the injected fuel may grow into droplets having a large particle size on the port wall surface. In this regard, according to the above-described conventional apparatus, when the fuel used is difficult to vaporize, the implementation rate of the intake asynchronous injection is reduced, so that the injected fuel flows into the combustion chamber as large droplets. Can be suppressed.

JP 2007-332936 A JP 2009-2211 A JP 2009-47055 A JP-A-11-270388 Japanese Patent Laid-Open No. 62-243937

  When mixed fuel with a high alcohol concentration is used, only the gasoline component of the mixed fuel injected from the fuel injector during the cold start of the internal combustion engine is vaporized, and the alcohol component is almost vaporized. do not do. For this reason, even when the intake synchronous injection at the time of starting is performed as in the above-described conventional device, there is a problem that the amount of vaporized fuel contributing to combustion is insufficient and the startability is likely to deteriorate. In addition, since the start-up is dependent on only the gasoline component of the injected mixed fuel, a large amount of fuel injection is required at the start-up to compensate for the shortage. Then, the alcohol component that is many times the amount of the gasoline component that contributed to the combustion cannot be vaporized and passes through the combustion chamber without being burned, and flows into the exhaust passage as HC. As a result, there is a problem that the amount of HC emission into the atmosphere tends to be extremely large at the cold start.

  The present invention has been made in order to solve the above-described problems, and in an internal combustion engine using a mixed fuel of gasoline and alcohol, the control of the internal combustion engine capable of suppressing emission deterioration during cold start. An object is to provide an apparatus.

In order to achieve the above object, a first invention is a control device for an internal combustion engine that can use a mixed fuel of gasoline and alcohol,
A fuel injector for injecting mixed fuel into the intake port of the internal combustion engine;
A heating device for heating the wall surface of the intake port;
Concentration acquisition means for acquiring the alcohol concentration of the mixed fuel;
Determination means for determining the presence or absence of a cold start request of the internal combustion engine;
When it is determined that there is a cold start request and the alcohol concentration is higher than a predetermined value, a preheating unit that performs a preheating process using the heating unit prior to starting,
Limiting means for limiting fuel injection in a state in which the intake valve is opened at the start of the internal combustion engine after performing the preheating treatment;
Equipped with a,
The limiting means sets the fuel injection period so that the end timing of the fuel injection is more advanced than the opening timing of the intake valve, and advances the fuel injection period as the alcohol concentration increases. Features.

According to a second invention, in the first invention,
The limiting means advances the fuel injection period in accordance with the rate of increase in the rotational speed of the internal combustion engine.

  According to the first invention, when the internal combustion engine is cold started and the alcohol concentration of the mixed fuel is higher than a predetermined value, the preheating process for heating the wall surface of the intake port is performed prior to the start. The In starting the internal combustion engine after the preheating process, fuel injection (intake-synchronized injection) in a state where the intake valve is opened is limited. For this reason, according to the present invention, it is possible to effectively suppress the injected mixed fuel from flowing into the combustion chamber without contacting the heated intake port wall surface. Deterioration can be effectively suppressed.

Further, according to the first invention, in starting the internal combustion engine after the preheating process, the end timing of the fuel injection is set such that the advance side of the opening timing of the intake valve (IVO). For this reason, according to the present invention, the injected mixed fuel is effectively brought into contact with the wall surface of the intake port and heated, so that the vaporization of the mixed fuel can be effectively promoted.

Further, according to the first invention, the advance amount of the fuel injection period is increased as the alcohol concentration of the mixed fuel is higher. For this reason, according to the present invention, the lower the vaporization characteristic of the mixed fuel, the longer the time during which the injected mixed fuel is in contact with the heated intake port wall surface, so the vaporization characteristic is low. Even with mixed fuel, vaporization can be promoted effectively.

According to the second invention, the advance amount of the fuel injection period is increased as the increase rate of the engine speed is larger. Therefore, according to the present invention, as the stroke time becomes shorter, the fuel injection period is advanced, so the time during which the injected mixed fuel is in contact with the heated intake port wall surface is shortened. The situation can be effectively suppressed.

It is a figure for demonstrating the system configuration | structure of Embodiment 1 of this invention. It is a figure for demonstrating intake synchronous injection and intake asynchronous injection. FIG. 3 is a diagram showing the transition of the combustion cycle at the start of the internal combustion engine 10 for each cylinder. 4 is a flowchart of a routine executed in Embodiment 1 of the present invention. FIG. 4 is a diagram showing a change over time in the vaporization rate of the mixed fuel injected into the intake port 28. 2 is a diagram for explaining the relationship between the combustion cycle of each cylinder and the engine speed when the internal combustion engine 10 is started. FIG. It is a figure for demonstrating the relationship between the alcohol concentration of mixed fuel, and the deterioration degree of HC emission. It is a figure for demonstrating the relationship between the alcohol concentration of mixed fuel, and the amount of advance of fuel injection timing. It is a figure which shows the relationship between the distillation rate of E80 and E0, and temperature.

  Several 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 10. The internal combustion engine 10 is used as a power source of a vehicle, for example. Although the internal combustion engine 10 of this embodiment shall be an in-line 4 cylinder type, the number of cylinders and cylinder arrangement | positioning of an internal combustion engine in this invention are not specifically limited. FIG. 1 shows a cross section of one cylinder of the internal combustion engine 10.

  The internal combustion engine 10 can be operated using gasoline as a fuel, and can also be operated using a fuel in which alcohol such as ethanol or methanol and gasoline are mixed (hereinafter referred to as “mixed fuel”). In this case, the mixed fuel can be used from a low concentration (for example, about several percent) to a high concentration (for example, 80% or more) of the alcohol component (ratio of the alcohol component).

  An intake passage 12 and an exhaust passage 14 are connected to the internal combustion engine 10. An air flow meter 16 that detects the amount of intake air is disposed in the intake passage 12. A throttle valve 18 is disposed downstream of the air flow meter 16. The opening degree of the throttle valve 18 is adjusted by the operation of the throttle motor 20. A throttle position sensor 22 for detecting the opening degree of the throttle valve 18 is disposed in the vicinity of the throttle valve 18. A catalyst 24 for purifying exhaust gas is installed in the exhaust passage 14.

  Each cylinder of the internal combustion engine 10 is provided with a fuel injector 28 for injecting fuel into the intake port 26. Further, a PTC heater 30 for heating the wall surface of the intake port 26 of each cylinder is embedded. Each cylinder of the internal combustion engine 10 is further provided with an intake valve 32, a spark plug 34 and an exhaust valve 36.

  A crank angle sensor 40 capable of detecting a rotation angle (crank angle) of the crankshaft 38 is installed in the vicinity of the crankshaft 38 of the internal combustion engine 10. The crank angle sensor 40 can detect the crank angle of the internal combustion engine 10 and the engine speed.

  Further, the system of this embodiment includes a fuel property sensor 48 in the middle of a fuel supply passage (not shown). The alcohol concentration of the mixed fuel increases or decreases according to the alcohol concentration of the fuel selected by the user for refueling. The fuel property sensor 48 can detect the alcohol concentration of the mixed fuel. As the fuel property sensor 48, for example, a sensor that detects the alcohol concentration by measuring the dielectric constant, refractive index, etc. of the fuel can be used.

  Further, the system of the present embodiment includes an accelerator position sensor 42 that detects the amount of depression of an accelerator pedal in a driver's seat of a vehicle on which the internal combustion engine 10 is mounted, a water temperature sensor 44 that detects a cooling water temperature of the internal combustion engine 10, and an internal combustion engine. A starter (starter) 46 having an electric motor that rotationally drives the crankshaft 38 when the engine 10 is started, and an ECU (Electronic Control Unit) 50 are provided. Various sensors and actuators including those described above are electrically connected to the ECU 50.

[Operation of Embodiment 1]
(About preheating treatment)
First, the preheating process performed in the internal combustion engine 10 of the first embodiment will be described. When a mixed fuel with a high alcohol concentration is used, only the gasoline component is vaporized out of the mixed fuel injected from the fuel injector 28 during the cold start of the internal combustion engine 10, and the alcohol component is It hardly evaporates. For this reason, there is a problem that the amount of vaporized fuel that contributes to combustion is insufficient and the startability is likely to deteriorate. In addition, since the start-up is dependent on only the gasoline component of the injected mixed fuel, a large amount of fuel injection is required at the start-up to compensate for the shortage. Then, an alcohol component that is many times the amount of the gasoline component that has contributed to combustion cannot pass through the combustion chamber without being vaporized and flows into the exhaust passage as HC. As a result, there is a problem that the amount of HC emission into the atmosphere tends to be extremely large at the cold start.

  Therefore, in the first embodiment, when the internal combustion engine 10 is started under the condition that the mixed fuel is difficult to vaporize, preheating processing for heating the port wall surface is performed prior to driving of the starter 44. More specifically, when it is determined that the mixed fuel is difficult to vaporize when a request for starting the internal combustion engine 10 is issued, the PTC heater 30 embedded in the wall surface of the intake port 26 is energized. I will do it. Whether the mixed fuel is difficult to vaporize is determined by determining whether the alcohol concentration of the mixed fuel is higher than a predetermined value, whether the port wall temperature (cooling water temperature) is lower than a predetermined value, or the like. it can. As a result, the fuel mixture injected into the intake port 26 can be effectively heated to promote vaporization.

(About fuel injection operation)
Next, with reference to FIG. 2, the fuel injection operation performed in the internal combustion engine 10 of the first embodiment will be described. The fuel injection operation performed in the internal combustion engine 10 of the first embodiment is classified into intake synchronous injection and intake asynchronous injection according to the injection timing. FIG. 2 is a view for explaining intake synchronous injection and intake asynchronous injection. In this figure, (A) shows a state of intake asynchronous injection, and (B) shows a state of intake synchronous injection.

  As shown in FIG. 2 (A), in the intake asynchronous injection, fuel injection is performed when the intake valve 32 is closed. When the intake asynchronous injection is performed, the injected mixed fuel stays in the intake port 26 temporarily. For this reason, when the port wall surface or the valve surface is at a high temperature, the vaporization characteristic of the mixed fuel can be effectively promoted by the contact with the portion.

  On the other hand, as shown in FIG. 2B, in the intake synchronous injection, fuel injection is performed when the intake valve 32 is open. When the intake synchronous injection is performed, the injected fuel flows into the combustion chamber as it is without staying in the intake port 26. That is, in the intake synchronous injection, the injected fuel flows into the combustion chamber without receiving a large amount of heat from the port wall surface or the valve surface. For this reason, the effect of promoting the vaporization characteristics of the mixed fuel by the intake synchronous injection is smaller than that of the intake asynchronous injection described above.

(Characteristic operation of this embodiment)
Next, the characteristic operation of the first embodiment will be described with reference to FIG. As described above, when the internal combustion engine 10 is started under the condition that the mixed fuel is difficult to vaporize, the preheating process is performed. Thereby, since the port wall surface of the intake port 26 can be heated in advance before fuel injection, vaporization of the injected mixed fuel can be promoted.

  Here, in order to enhance the effect of promoting vaporization by the preheating treatment, it is preferable to bring a larger amount of fuel into contact with the port wall surface. In this regard, focusing on the fuel injection mode described above, in the asynchronous intake fuel injection, a larger amount of fuel can be brought into contact with the port wall surface than in the intake air synchronous injection. Is possible.

  Therefore, in the apparatus according to the first embodiment, the execution of intake synchronous injection is prohibited when the engine is started after the preheating process. Hereinafter, a specific example will be described with reference to FIG. FIG. 3 is a diagram showing the transition of the combustion cycle at the start of the internal combustion engine 10 for each cylinder. In the combustion cycle shown in this figure, the second cylinder starts from the intake stroke. For this reason, if the intake-synchronized injection is performed in the intake stroke, the timing of the first explosion can be effectively advanced. However, as described above, in the intake synchronous injection, there is a possibility that the vaporization promoting effect by the preheating process cannot be sufficiently obtained. For this reason, if the intake-synchronized injection is executed in the intake stroke of the second cylinder, there is a risk of causing a deterioration in emissions due to poor combustion.

  Therefore, in the combustion cycle shown in FIG. 3, intake synchronous injection of the second cylinder is prohibited, and fuel injection is started from the first cylinder capable of intake asynchronous injection. Thereby, starting can be performed in a state where the vaporization promoting effect by the preheating treatment is sufficiently obtained, so that startability can be improved effectively and deterioration of HC emissions can be effectively suppressed.

[Specific processing of this embodiment]
Next, specific processing of the present embodiment will be described with reference to FIG. FIG. 4 is a flowchart of a routine executed by the ECU 50 in the present embodiment in order to realize the above-described start-time control. In the routine shown in FIG. 4, first, it is determined whether or not there is an engine start request (step 100). Specifically, it is determined whether or not a signal (for example, a seating signal or an ignition signal) for detecting that the driver will start the engine in the near future has been issued. As a result, when it is determined that there is still no engine start request, this step 100 is repeatedly executed.

  On the other hand, if it is determined in step 100 that there is a request for starting the engine, the process proceeds to the next step, and the alcohol concentration of the mixed fuel is acquired based on the detection signal of the fuel property sensor 48 (step). 102). Next, it is determined whether or not the alcohol concentration acquired in step 102 is greater than a predetermined value A. As the predetermined value A, a value set in advance is read as a concentration at which an unacceptable vaporization failure occurs during cold start. As a result, when the establishment of the alcohol concentration> predetermined value A is not recognized, it is determined that a considerable amount of low-boiling components are contained in the mixed fuel, and vaporization failure does not occur even if the preheating process is not performed. Then, the process proceeds to step 116 described later, and fuel injection is permitted.

  On the other hand, if it is confirmed in step 104 that the alcohol concentration> predetermined value A is established, the low boiling point component contained in the mixed fuel is insufficient, and therefore vaporization failure occurs unless the preheating process is performed. When it is determined that there is a risk, the process proceeds to the next step, and the cooling water temperature is acquired based on the detection signal of the water temperature sensor 44 (step 106). Next, it is determined whether or not the cooling water temperature is lower than a predetermined value B (step 108). As the predetermined value B, a preset value is read as a threshold value for determining whether or not the port wall temperature of the internal combustion engine 10 is a temperature that requires preheating processing. As a result, if it is not recognized that the cooling water temperature <predetermined value B, it is determined that the port wall temperature is sufficiently high without performing the preheating process, and the routine proceeds to step 116 described later, where fuel injection is performed. Allowed.

  On the other hand, if it is determined in step 108 that the cooling water temperature <predetermined value B is established, the port wall temperature is low, so that it is determined that vaporization failure may occur unless the preheating process is performed. Then, the preheating process is executed (step 110). Here, specifically, the required heating amount of the port wall surface is set based on the cooling water temperature acquired in step 106. Then, the PTC heater 30 is driven for a predetermined period, and a heat amount corresponding to the required heating amount is received by the port wall surface.

  In the routine shown in FIG. 4, next, the starter 46 is driven to start cranking (step 112). Next, it is determined whether or not intake asynchronous injection can be performed (step 114). Specifically, first, based on the detection signal of the crank angle sensor 40, it is determined whether the next stroke of each cylinder belongs to intake, compression, expansion, or exhaust. Then, in each stroke of each cylinder, it is determined whether or not intake asynchronous injection can be performed. As a result, for the cylinder that is determined to be unable to perform the intake asynchronous injection, this step 114 is executed again in the next stroke. On the other hand, for the cylinder determined to be unable to perform the intake asynchronous injection in step 114, the process proceeds to the next step, and fuel injection is permitted (step 116).

  As described above, according to the apparatus of the first embodiment, fuel injection is permitted from a cylinder capable of intake asynchronous injection when the preheating process is performed. Thereby, since execution of intake synchronous injection is effectively limited, the effect of promoting the vaporization of the mixed fuel by the preheating process can be effectively enhanced.

  By the way, in Embodiment 1 mentioned above, it is supposed as energization to the PTC heater 30 embedded in the port wall surface as preheating processing, However, The method of preheating processing is not restricted to this. That is, if the port wall surface can be heated, for example, a heat storage hot water supply system that supplies hot water into the cylinder head may be used. This also applies to Embodiments 2 and 3 described later.

  Further, in the first embodiment described above, the alcohol concentration of the mixed fuel is detected using the fuel property sensor 48, but the method of detecting the alcohol concentration is not limited to this. For example, the alcohol concentration of the fuel may be detected (estimated) from the learned value in the air-fuel ratio feedback control. That is, since the value of the theoretical air-fuel ratio is different between gasoline and alcohol, the value of the theoretical air-fuel ratio of the alcohol-mixed fuel differs depending on the alcohol concentration. Therefore, the alcohol concentration of the fuel in the tank is detected (estimated) based on the value of the theoretical air-fuel ratio learned by feeding back a signal from an air-fuel ratio sensor (not shown) provided in the exhaust passage 14. Is possible. This also applies to Embodiments 2 and 3 described later.

  In the first embodiment described above, the PTC heater 30 corresponds to the “heating device” in the first invention, and the fuel property sensor 48 corresponds to the “concentration acquisition means” in the first invention. . Further, when the ECU 50 executes the processing of the steps 100 and 108, the “determination means” in the first invention executes the processing of the step 110, whereby the “preheating means in the first invention. “,” By executing the processing of step 114 above, the “restricting means” in the first invention is realized.

Embodiment 2. FIG.
[Features of Embodiment 2]
Next, a second embodiment of the present invention will be described with reference to FIG. In the first embodiment described above, in the start after the preheating process, the execution of the intake synchronous injection is prohibited and the fuel injection is executed from the cylinder capable of the intake asynchronous injection. Thereby, since the contact amount to the port wall surface of the injected mixed fuel can be increased, the vaporization promotion effect by a preheating process can be heightened effectively.

  However, as described above, the higher the alcohol concentration of the mixed fuel, the worse the vaporization characteristics of the mixed fuel. For this reason, in the case of using a high-concentration mixed fuel, even if the mixed fuel is brought into contact with the port wall surface, it is assumed that vaporization promotion is insufficient.

  FIG. 5 is a diagram showing a change over time in the evaporation rate of the mixed fuel injected into the intake port 28. As shown in this figure, the vaporization rate of the mixed fuel increases as time elapses. In the second embodiment, therefore, the vaporization of the mixed fuel is further promoted by increasing the contact time between the mixed fuel and the port wall surface. More specifically, in addition to the control of the first embodiment, the injection timing of the intake asynchronous injection is advanced (advanced) as the alcohol concentration of the mixed fuel is higher. As a result, the worse the vaporization characteristics of the mixed fuel, the longer the contact time between the mixed fuel and the port wall surface. Therefore, even when the alcohol concentration of the mixed fuel is high, the vaporization is effectively promoted. be able to.

Embodiment 3 FIG.
[Features of Embodiment 3]
In the first and second embodiments described above, the intake air asynchronous injection is performed at the start after the preheating process. Here, the combustion cycle time of the internal combustion engine 10 varies according to the engine speed. FIG. 6 is a diagram for explaining the relationship between the combustion cycle of each cylinder and the engine speed when the internal combustion engine 10 is started. In this figure, the starter 46 is driven at time t0. As shown in FIG. 6, when the first explosion is performed in the first cylinder at time t1, the engine speed thereafter increases. As the engine speed increases, the time required for each stroke decreases. For this reason, in the fuel injection after the first explosion (for example, the second cylinder), it is assumed that the intake stroke is started before the fuel injection is ended, and as a result, the intake synchronous injection is performed.

  This is also related to the alcohol concentration of the mixed fuel. That is, the required injection period when using the mixed fuel is longer than that when using gasoline. This is due to the difference in the lower heating value of the fuel. The higher the alcohol concentration of the mixed fuel, the longer the required injection period. For this reason, if the fuel injection timing is set without considering the length of the injection period due to the high or low alcohol concentration, the intake stroke starts before the fuel injection ends, and as a result, the second half of the fuel injection period is synchronized with the intake air. It is assumed that it becomes injection.

  Therefore, in the third embodiment, the fuel injection timing is accelerated according to the increase in the engine speed and the alcohol concentration of the mixed fuel. More specifically, the IVO of the target cylinder is specified based on the increase in the engine speed, and control is performed so that the end timing of the fuel injection is advanced from the IVO. Further, when the fuel injection period is increased due to the use of the high-concentration mixed fuel, the start timing of the fuel injection is advanced by the increased amount. As a result, the intake asynchronous injection can be reliably performed even when the engine speed is increased or the alcohol concentration of the mixed fuel is changed.

  When the engine speed increases, the time during which the mixed fuel injected by the intake asynchronous injection is in contact with the port wall surface, that is, the heat receiving time of the mixed fuel is shortened. Therefore, when the fuel injection period is advanced (advanced) according to the engine speed, it is preferable to further set the fuel injection period to the advanced angle side in consideration of securing the heat receiving time. Thereby, further vaporization promotion of mixed fuel can be aimed at.

  Further, as described above in the second embodiment, when using a high-concentration mixed fuel with poor vaporization characteristics, the time during which the mixed fuel injected by the intake asynchronous injection is in contact with the port wall surface is insufficient. There is a risk that HC emissions will deteriorate. FIG. 7 is a diagram for explaining the relationship between the alcohol concentration of the mixed fuel and the degree of deterioration of HC emission. As shown in this figure, HC emission tends to deteriorate rapidly after a predetermined alcohol concentration due to the deterioration of the vaporization characteristics of the mixed fuel.

  Therefore, when the fuel injection period is advanced (advanced) in accordance with the alcohol concentration of the mixed fuel, it is preferable to change the fuel injection period in accordance with the degree of deterioration of HC emission shown in FIG. FIG. 8 is a diagram for explaining the relationship between the alcohol concentration of the mixed fuel and the advance amount of the fuel injection timing. As shown in this figure, below the predetermined alcohol concentration, the fuel injection timing is linearly advanced in accordance with the change in the lower heating value of the mixed fuel. After the predetermined alcohol concentration, the above-described change in the lower heating value is performed. In addition to the minute, it is preferable to further advance the deterioration of the HC emission, that is, the deterioration of the vaporization characteristic of the mixed fuel. Thereby, further vaporization promotion of mixed fuel can be aimed at.

10 Internal combustion engine 12 Intake passage 14 Exhaust passage 16 Air flow meter 18 Throttle valve 24 Catalyst 26 Intake port 28 Fuel injector 30 PTC heater 32 Intake valve 34 Spark plug 36 Exhaust valve 38 Crankshaft 40 Crank angle sensor 42 Accelerator position sensor 44 Water temperature sensor 46 Starter 48 Fuel property sensor 50 ECU

Claims (2)

A control device for an internal combustion engine capable of using a mixed fuel of gasoline and alcohol,
A fuel injector for injecting mixed fuel into the intake port of the internal combustion engine;
A heating device for heating the wall surface of the intake port;
Concentration acquisition means for acquiring the alcohol concentration of the mixed fuel;
Determination means for determining the presence or absence of a cold start request of the internal combustion engine;
When it is determined that there is a cold start request and the alcohol concentration is higher than a predetermined value, a preheating unit that performs a preheating process using the heating unit prior to starting,
Limiting means for limiting fuel injection in a state in which the intake valve is opened at the start of the internal combustion engine after performing the preheating treatment;
Equipped with a,
The limiting means sets the fuel injection period so that the end timing of the fuel injection is more advanced than the opening timing of the intake valve, and advances the fuel injection period as the alcohol concentration increases. A control device for an internal combustion engine characterized by the above. Said limiting means in response to said rotational speed increase rate of the internal combustion engine, the control apparatus for an internal combustion engine according to claim 1, characterized in that advancing the fuel injection period.

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