Fuel injection control device for internal combustion engine

Abstract

To provide a fuel injection control device, for an interna combustion engine, which reduces battery consumption when the internal combustion engine is started up by deriving a fuel injection amount allowing for quick start-up thereof in the internal combustion engine capable of using either alcohol, gasoline, or mixed fuel of alcohol and gasoline as fuel.SOLUTION: A fuel injection control device is for an internal combustion engine capable of using either alcohol, gasoline or mixed fuel of alcohol and gasoline as fuel. The fuel injection control device: has three or more fuel injection amount control maps; stores a fuel injection amount control map Mx immediately before stopping the internal combustion engine 1; executes a start-up of the internal combustion engine 1 with the fuel injection amount control map Mx immediately before stopping the internal combustion engine 1 as a selected fuel injection amount control map MS; and switches the selected fuel injection control map Ms, when determining that the internal combustion engine 1 has a defective start-up, to a fuel injection amount control map MS+2,MS-2 following a numbering sequence from a fuel injection amount control map MS+1,MS-1 in the selected fuel injection amount control map MS.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present invention relates to a fuel injection control device for an internal combustion engine that controls the amount of fuel injected at the start of an internal combustion engine equipped with a flexible fuel function that can be operated using gasoline, alcohol, or a mixed fuel that is a mixture of both. [Background technology]

[0002] In recent years, in light of global warming, alcohol fuels, especially bioethanol, have been attracting attention as an alternative fuel, as they are carbon-neutral fuels because they are made from plants grown through photosynthesis using solar energy, and therefore the total amount of CO2 in the atmosphere does not increase even when energy is extracted from the fuel. Therefore, in recent years, instead of vehicles equipped with conventional internal combustion engines that use gasoline as fuel, vehicles equipped with internal combustion engines with a so-called flexible fuel function that can run on either gasoline, alcohol, or an alcohol blend fuel that is a mixture of gasoline and alcohol are being used.Internal combustion engines with such flexible fuel function have issues that are different from those that use gasoline.

[0003] Alcohol fuels and alcohol-blended fuels are fuels that consist only of alcohol or a mixture of alcohol and gasoline. Due to the combustion characteristics of alcohol, the fuel does not vaporize easily at low temperatures, making it difficult for the internal combustion engine to start.

[0004] Furthermore, alcohol-blended fuels with different blend ratios are available on the market, such as E100, which is 100% ethanol; E85, which is a blend of 85% ethanol and gasoline; E50, which is a blend of 50% ethanol and gasoline; and E25, which is a blend of 25% ethanol and gasoline.

[0005] When fuel is supplied, the internal combustion engine is stopped, but if an alcohol-mixed fuel with a different concentration than before the internal combustion engine was stopped is supplied to the fuel tank, the alcohol concentration will be different from the alcohol concentration immediately before the engine was stopped. Therefore, if the engine is started with the optimal fuel injection amount for the concentration recognized by the control device immediately before the engine was stopped, the fuel injection amount will be insufficient or excessive, and the internal combustion engine will not be able to start.

[0006] Therefore, when starting an internal combustion engine, a start-up determination means initiates the start-up using an ethanol concentration estimated value stored in an ECU (engine control unit), and if it is determined that the internal combustion engine is having trouble starting, the fuel injection amount is corrected using a second ethanol concentration estimated value that is different from the first ethanol concentration estimated value, and if it is further determined that the internal combustion engine is having trouble starting, the fuel injection amount is corrected using a third ethanol concentration estimated value that is different from the second ethanol concentration estimated value (see Patent Document 1). [Prior art documents] [Patent documents]

[0007] [Patent Document 1] Japanese Patent Application Laid-Open No. 2007-1469831 Summary of the Invention [Problem to be solved by the invention]

[0008] In a fuel injection control device for an internal combustion engine with such a flexible fuel function, when starting the internal combustion engine, the system starts using the estimated ethanol concentration value stored in the ECU. If the internal combustion engine is determined to have difficulty starting, the estimated ethanol concentration value is changed multiple times before the ethanol concentration is estimated, which causes the internal combustion engine to take time to start and consumes the battery's electrical capacity. [Means for solving the problem]

[0009] In order to solve the above problems, the present invention provides an internal combustion engine that can use any one of alcohol, gasoline, and a mixed fuel of alcohol and gasoline as fuel, a fuel tank in which any of the fuels is stored; a fuel injection device that supplies fuel stored in the fuel tank to an internal combustion engine; 1. A fuel injection control device for an internal combustion engine that controls a fuel injection amount of the fuel injection device in accordance with an alcohol concentration of the fuel, three or more fuel injection amount control maps for controlling the fuel injection amount of the internal combustion engine in accordance with the range of alcohol concentration of the fuel; the plurality of fuel injection amount control maps (M1, M2, M3, M4) are assigned map numbers in sequence from a map having a low alcohol concentration to a map having a high alcohol concentration; the plurality of fuel injection amount control maps are configured so that the internal combustion engine can be started based on the alcohol concentration of the fuel in adjacent fuel injection amount control maps in the order of map numbers of the selected fuel injection amount control map selected based on the alcohol concentration of the fuel, when the internal combustion engine is stopped, a pre-stop fuel injection amount control map immediately before the internal combustion engine is stopped is set as the selected fuel injection amount control map; When starting the internal combustion engine, the immediately before-stop fuel injection amount control map is selected; starting the internal combustion engine with a fuel injection amount based on the selected fuel injection amount control map; This is a fuel injection control device for an internal combustion engine, characterized in that when it is determined that the internal combustion engine is having trouble starting, the selected fuel injection amount control map is switched to the fuel injection amount control map next to the adjacent fuel injection amount control map in the map number order of the selected fuel injection amount control map, and the start of the internal combustion engine is initiated.

[0010] According to the present invention, in a fuel injection control device for an internal combustion engine that can use alcohol, gasoline, or a mixed fuel of alcohol and gasoline as fuel, a plurality of fuel injection amount control maps are configured so that the internal combustion engine can be started based on the alcohol concentration of the fuel even when adjacent fuel injection amount control maps in map number order of the fuel injection amount control map selected based on the alcohol concentration of the fuel are used, and when starting the internal combustion engine, the immediately before-stop fuel injection amount control map stored when the internal combustion engine was last stopped is used as the selected fuel injection amount control map, and starting of the internal combustion engine is initiated with a fuel injection amount based on the selected fuel injection amount control map, and if it is determined that the internal combustion engine is not starting properly, the selected fuel injection amount control map is switched to the fuel injection amount control map next adjacent to the adjacent fuel injection amount control map in map number order of the selected fuel injection amount control map, and starting of the internal combustion engine is initiated.Therefore, a fuel injection amount that can start the internal combustion engine can be derived in a short time, ignition performance at the time of starting the internal combustion engine is improved, starting performance of the internal combustion engine is improved, and battery consumption at the time of starting the internal combustion engine is reduced.

[0011] In the above configuration, the number of fuel injection amount control maps may be four.

[0012] According to the above configuration, since there are four fuel injection amount control maps, if the internal combustion engine cannot be started within a predetermined time, fuel injection is controlled based on the next fuel control map. Therefore, the internal combustion engine can be started by changing the fuel control map only once, thereby further improving the startability of the internal combustion engine. [Effects of the Invention]

[0013] The present invention is a fuel injection control device for an internal combustion engine that can be operated with gasoline, alcohol, or a mixed fuel of both, and it derives a fuel injection amount that can start the internal combustion engine in a short time, improves the ignition performance when the internal combustion engine is started, improves the startability of the internal combustion engine, and reduces battery consumption when the internal combustion engine is started. [Brief explanation of the drawings]

[0014] [Figure 1] 1 is a block diagram illustrating an embodiment of the present invention. [Figure 2] FIG. 10 is a diagram showing the allocation of multiple control groups to the blend ratio of gasoline and ethanol. [Figure 3] FIG. 4 is a diagram showing a flow at the time of starting the internal combustion engine. [Figure 4] FIG. 4 is a diagram showing an example of selection of a fuel injection amount control map at the time of starting the internal combustion engine. [Figure 5] FIG. 4 is a diagram showing an example of selection of a fuel injection amount control map at the time of starting the internal combustion engine. [Figure 6] FIG. 4 is a diagram showing an example of selection of a fuel injection amount control map at the time of starting the internal combustion engine. [Figure 7] FIG. 4 is a diagram showing an example of selection of a fuel injection amount control map at the time of starting the internal combustion engine. [Figure 8] FIG. 10 is a diagram showing an example of a fuel injection amount control map selected based on the alcohol concentration of fuel and adjacent fuel injection amount control maps. DETAILED DESCRIPTION OF THE INVENTION

[0015] 1 is a schematic diagram showing an internal combustion engine fuel injection control device 20 of the present invention and an internal combustion engine 1 that uses the fuel injection control device 20. The internal combustion engine 1 is an internal combustion engine equipped with a so-called flexible fuel function that allows it to be operated on gasoline, alcohol fuel, or a fuel that is a mixture of gasoline and alcohol in any ratio, and is mounted on a vehicle (not shown). Ethanol, for example, is used as the alcohol fuel. One example of this ethanol is bioethanol, which is produced from plants grown through photosynthesis using solar energy.

[0016] As shown in FIG. 1, the vehicle is equipped with a fuel tank 5. The fuel tank 5 stores alcohol fuel, a mixed fuel in which alcohol fuel and gasoline are mixed in any ratio, or gasoline. The fuel tank 5 is connected to a fuel injection valve 7 that injects fuel into an intake passage 2 of the internal combustion engine 1 via a fuel supply pipe 6. The fuel injection valve 7 injects an amount of fuel according to the combustion state of the internal combustion engine 1 and various other conditions. In this embodiment, the fuel injection valve 7 is installed so as to inject fuel into the intake passage 2, but it may also be installed so as to inject fuel directly into the combustion chamber of the internal combustion engine 1.

[0017] An intake passage 2 through which outside air is supplied is connected to an intake port 1a of the internal combustion engine 1, and an exhaust passage 3 through which exhaust gas after combustion is discharged is connected to an exhaust port 1b of the internal combustion engine. A throttle valve 8 that controls the intake air flow rate is disposed in the intake passage 2, and a throttle sensor 10 that detects the throttle opening θth of the throttle valve 8 is attached. Furthermore, a Pb sensor 11 that detects the intake negative pressure Pb is disposed downstream of the throttle valve 8 in the intake passage 2. An oxygen sensor 12 that detects the oxygen concentration Vo2 in the exhaust gas is attached to the exhaust passage 3. The vehicle is also provided with an outside air temperature sensor 15 that detects the outside air temperature To.

[0018] Furthermore, the internal combustion engine 1 is equipped with a water temperature sensor 13 that detects the coolant temperature Tw of the internal combustion engine 1, a crank angle sensor 14 that detects the rotation speed Ne of the internal combustion engine, etc. Detection signals detected by the various sensors are sent to an engine control unit 18 (hereinafter referred to as ECU 18).

[0019] The ECU 18 monitors the ON-OFF signal of the starter switch 9 to determine whether or not a starter motor (not shown) has been driven by the driver's operation of an engine key (not shown).

[0020] As shown in FIG. 2, the fuel injection control device 20 is configured with multiple control groups corresponding to the mixture ratio of gasoline and alcohol, i.e., the range of alcohol concentration, and employs a method of selecting and switching to an appropriate fuel injection state by selecting a control group according to the alcohol concentration of the fuel.

[0021] A control group is a collection of controls that should be controlled depending on a predetermined range of alcohol concentration, such as a fuel injection amount map, injection timing, ignition timing, etc. In other words, a collection of these controls is prepared in advance for each control group that corresponds to the set range of alcohol concentration.

[0022] The control groups are divided into a plurality of groups according to a predetermined range of alcohol concentration of the fuel, and in this embodiment, the control groups are divided into four control groups, namely, first control group, second control group, third control group, and fourth control group, in order of increasing alcohol concentration, as shown in Figure 2. In this embodiment, the number of control groups is four, but it does not have to be four, as long as it is three or more.

[0023] In this embodiment, the reference concentrations of the four control groups are allocated within a predetermined range between 0% alcohol (100% gasoline) and 100% alcohol (0% gasoline). In this embodiment, specifically, a control group is assigned to each of the four levels of alcohol concentration. The control groups are numbered in order from lowest to highest median alcohol concentration range for each control group, i.e., Control Group 1, Control Group 2, Control Group 3, and Control Group 4, in order from lowest to highest median alcohol concentration range for each control group. As shown in FIG. 2, the corresponding alcohol concentration ranges of adjacent control groups in the order of control group numbers are set to partially overlap.

[0024] Each control group has a respective fuel injection amount control map for controlling the fuel injection amount, and in this embodiment, there are four fuel injection amount control maps. These fuel injection amount control maps are assigned fuel injection amount control map numbers in order from lowest to highest in the median value of the corresponding alcohol concentration range so as to correspond to the control groups. That is, as shown in FIG. 8, map numbers are assigned in order from lowest to highest in the median value of the corresponding alcohol concentration range in each fuel injection amount control map, such as a first fuel injection amount control map M1, a second fuel injection amount control map M2, a third fuel injection amount control map M3, and a fourth fuel injection amount control map M4. The fuel injection control device 20 selects the selected fuel injection amount control map M1 as appropriate. S The fuel injection amount is controlled based on the above.

[0025] These multiple fuel injection amount control maps M1, M2, M3, and M4 are selected based on the alcohol concentration of the fuel. S Adjacent fuel injection amount control maps M in the order of map numbers S+1 ,M S-1 The internal combustion engine 1 is configured to be able to start based on the alcohol concentration of the fuel even in this case. For example, as shown in FIG. 8, when the second control group is selected based on the alcohol concentration of the fuel, the second fuel injection amount control map M2 belonging to the second control group is selected, and the selected fuel injection amount control map M2 is set as the selected fuel injection amount control map M S This becomes: In this case, the selected fuel injection amount control map M S The third fuel injection amount control map M3 (fuel injection amount control map M2) is adjacent to the second fuel injection amount control map M2 in the order of map numbers. S+1 ) and the first fuel injection amount control map M1 (fuel injection amount control map M S-1 ), the fuel injection amount control map is configured so that the internal combustion engine 1 can be started based on the alcohol concentration of the fuel.

[0026] As described above, the ECU 18 selects an appropriate control group depending on the alcohol concentration of the fuel supplied to the internal combustion engine 1. When the internal combustion engine 1 is operating, a typical feedback control is performed in which a feedback correction factor is applied to the fuel injection amount control map to achieve an appropriate air-fuel ratio based on the output of the oxygen sensor 12, and rich / lean control is repeated. However, if the feedback correction factor is above or below a predetermined value, the control group is determined to be inappropriate, and the ECU 18 switches to the adjacent control group in the direction of correcting the deviation in the map. The most recently selected control group is always stored in the ECU 18, and is selected first the next time the internal combustion engine 1 is started.

[0027] When the internal combustion engine 1 is started, the internal combustion engine 1 is not in a combustion state, so an appropriate control group cannot be selected based on the output value of the oxygen sensor 12. Therefore, the control group when the internal combustion engine 1 is started is determined based on the flowchart shown in FIG.

[0028] First, when the ECU 18 receives an ON signal from the starter switch 9 in response to the driver's operation of the engine key, it determines that a start operation for the internal combustion engine 1 has begun, and proceeds to step S2.

[0029] In step S2, it is determined whether the outside air temperature To detected by the outside air temperature sensor 15 is equal to or lower than a predetermined value To1.

[0030] If the outside air temperature To is equal to or lower than a predetermined value To1, the process proceeds to step S3, where the low temperature start mode is entered. In the low temperature start mode, a low temperature start device (not shown), such as a heater that warms the fuel pipes and intake passage, is started to start heating the fuel and intake air. When the outside air temperature is low, the startability of the internal combustion engine decreases due to the reduced vaporization of ethanol at low temperatures, so the low temperature start device is started to improve the startability of the internal combustion engine 1. After the low temperature start device is started, the process proceeds to step S5.

[0031] If the outside air temperature To is not equal to or lower than the predetermined value To1, that is, if the outside air temperature To is higher than the predetermined value To1, the process proceeds to step S4.

[0032] In step 4, the control group stored in the ECU 18 immediately before the stop of the internal combustion engine 1 before the current start is selected as the control group for the current start of the internal combustion engine 1, and the immediately before-stop fuel injection amount control map M X However, the selected fuel injection amount control map M S is selected, and then the process proceeds to step S5.

[0033] For example, if the first control group is stored as the control group immediately before the internal combustion engine 1 is stopped, the first control group is selected as the control group for the current start of the internal combustion engine 1. Furthermore, when the first control group is selected, the first fuel injection amount control map M1 in the first control group is set to the selected fuel injection amount control map M S is selected, and the fuel injection control during the current start of the internal combustion engine 1 is performed based on the first fuel injection amount control map M1.

[0034] The process proceeds to step S5, where the starter motor of the internal combustion engine 1 is turned on.

[0035] Then, the process proceeds to step S6, where the rotation speed Ne of the internal combustion engine is compared with a predetermined rotation speed Ne1 after a predetermined time has elapsed since the starter motor of the internal combustion engine 1 was turned on. If it is determined in step S6 that Ne is equal to or greater than Ne1, it is determined that the internal combustion engine 1 has started, and the process proceeds to step S7.

[0036] In step S7, the basic start mode is entered, and the combustion of the internal combustion engine 1 thereafter is controlled based on the selected control group, and the fuel injection amount control map in the selected control group is the selected fuel injection amount control map M SAfter the internal combustion engine 1 starts, feedback correction is performed as appropriate based on the output of the oxygen sensor 12, and if it is determined that the control group is inappropriate, the control group is switched to the adjacent control group in the direction in which the deviation of the map is corrected as needed, and accordingly, the fuel injection amount control map in that control group is changed to the selected fuel injection amount control map M S Thus, the amount of fuel injected into the internal combustion engine 1 is controlled.

[0037] In step S6, if it is determined that the rotation speed Ne of the internal combustion engine 1 is not equal to or greater than the predetermined rotation speed Ne1 after a predetermined time has elapsed since the starter motor of the internal combustion engine 1 was turned on, that is, Ne is smaller than Ne1, it is determined that the internal combustion engine 1 has a starting failure. S is determined to be inappropriate, the process proceeds to step S8, and the selected fuel injection amount control map M S Change the

[0038] In step S8, the currently selected fuel injection amount control map M S That is, the selected fuel injection amount control map M selected at the start of the internal combustion engine S As shown in Figs. 4 to 7, the selected fuel injection amount control map M S This selective fuel injection amount control map M S Adjacent fuel injection amount control maps M in map number order S+1 ,M S-1 The next fuel injection amount control map M S+2 ,M S-2 Change to. That is, the selected fuel injection amount control map M S However, when the first fuel injection amount control map M1 is selected, the map is changed to the third fuel injection amount control map M3; when the second fuel injection amount control map M2 is selected, the map is changed to the fourth fuel injection amount control map M4; when the third fuel injection amount control map M3 is selected, the map is changed to the first fuel injection amount control map M1; and when the fourth fuel injection amount control map M4 is selected, the map is changed to the second fuel injection amount control map M2.

[0039] The fuel injection amount control maps M1, M2, M3, and M4 are selected based on the alcohol concentration of the fuel. S Adjacent fuel injection amount control maps M in the order of map numbers S+1 ,M S-1 Therefore, the alcohol concentration of the fuel supplied to the internal combustion engine 1 is calculated based on the selected fuel injection amount control map M S The fuel injection amount control map M adjacent to S+1 ,M S-1 is within the range of the selected alcohol concentration, the fuel injection amount control map M S+2 ,M S-2 The start of the internal combustion engine 1 is guaranteed.

[0040] In step S9, similar to step S6, the rotation speed Ne of the internal combustion engine 1 after a predetermined time has elapsed since the starter motor of the internal combustion engine 1 was turned on is compared with a predetermined rotation speed Ne1. If it is determined in step S9 that Ne is equal to or greater than Ne1, it is determined that the internal combustion engine 1 has been started, and the process proceeds to step S7.

[0041] In step 9, the rotation speed Ne of the internal combustion engine after a predetermined time has elapsed since the starter motor of the internal combustion engine 1 was turned on is compared with a predetermined rotation speed Ne1, and if it is determined that Ne is smaller than Ne1, it is determined that the internal combustion engine 1 could not be started, and a warning display device mounted on the vehicle displays a warning that the internal combustion engine could not be started.

[0042] The fuel injection control device 20 for an internal combustion engine according to the embodiment of the present invention is configured as described above, and therefore has the following effects.

[0043] A fuel injection control device 20 for an internal combustion engine according to an embodiment of the present invention is used in an internal combustion engine 1 that can use any one of alcohol, gasoline, and a mixed fuel of alcohol and gasoline as fuel, and includes a fuel tank 5 that stores any one of the fuels, a fuel injection device 7 that supplies the fuel stored in the fuel tank 5 to the internal combustion engine 1, and a fuel injection control device for an internal combustion engine that controls the fuel injection amount of the fuel injection device 7 in accordance with the alcohol concentration of the fuel. The fuel injection control device further includes four fuel injection amount control maps that control the fuel injection amount of the internal combustion engine 1 in accordance with the range of alcohol concentration of the fuel, and includes a first fuel injection amount control map M1, a second fuel injection amount control map M2, a third fuel injection amount control map M3, and a fourth fuel injection amount control map M4. Furthermore, these first fuel injection amount control map M1, second fuel injection amount control map M2, third fuel injection amount control map M3, and fourth fuel injection amount control map M4 are selected based on the alcohol concentration of the fuel. S Adjacent fuel injection amount control maps M in the order of map numbers S+1 ,M S-1 In this case, the internal combustion engine 1 can be started based on the alcohol concentration of the fuel. When the internal combustion engine 1 is stopped, the fuel injection amount control map M X When the internal combustion engine 1 is started, the immediately before-stop fuel injection amount control map M x Select fuel injection quantity control map M S and the selected fuel injection amount control map M S When it is determined that the internal combustion engine 1 is not starting properly, the selected fuel injection amount control map M S Selective fuel injection amount control map M S Adjacent fuel injection amount control maps M in the order of map numbers S+1 ,M S-1 The next fuel injection amount control map M S+2 ,M S-2 and starts starting the internal combustion engine 1.

[0044] According to the above configuration, when the internal combustion engine 1 cannot be started, the fuel injection amount control map M stored at the time of the last stop of the internal combustion engine 1 is used. S Adjacent fuel injection amount control maps M in the order of map numbers S+1 ,M S-1 Select fuel injection quantity control map M S Instead of selecting the fuel injection amount control map M S Adjacent fuel injection amount control map M S+1 ,M S-1 The next fuel injection amount control map M S+2 ,M S-2 Select fuel injection quantity control map M S Since the internal combustion engine 1 can be started without selecting the fuel injection amount control map multiple times, it is possible to derive a fuel injection amount that can start the internal combustion engine 1 in a short time, improve the ignition ability at the start of the internal combustion engine 1, and improve the startability, thereby reducing battery consumption at the start of the internal combustion engine 1.

[0045] Furthermore, since there are four fuel injection amount control maps, namely, the first fuel injection amount control map M1, the second fuel injection amount control map M2, the third fuel injection amount control map M3, and the fourth fuel injection amount control map M4, when the internal combustion engine 1 cannot be started within a predetermined time, fuel injection is controlled based on the fuel control map that is skipped in map number order. Therefore, the internal combustion engine 1 can be started by changing the fuel control map only once, thereby further improving the startability of the internal combustion engine 1.

[0046] The fuel injection control device for an internal combustion engine according to this embodiment is provided with four fuel injection amount control maps, but if five or more fuel injection amount control maps are provided, the fuel injection amount control maps are switched as follows. If the internal combustion engine 1 cannot be started using the initially selected fuel injection amount control map, the fuel injection amount control map is switched to the next fuel injection amount control map in the direction of increasing or decreasing map number order. In this state, the starter motor of the internal combustion engine 1 is turned on to start cranking, and if the internal combustion engine 1 cannot be started, the next fuel injection amount control map in the same direction is selected, and the starter motor is turned on to start cranking. If the internal combustion engine 1 does not start even after repeating this process and there are no more fuel injection amount control maps to select in the same direction, the system returns to the initially selected fuel injection amount control map, switches to the fuel injection amount control map that is one map number ahead in the opposite direction to the initially selected direction in map number order, turns on the start motor of the internal combustion engine 1, and starts cranking; if the internal combustion engine 1 cannot start, it selects another fuel injection amount control map that is one map ahead in the same direction, turns on the start motor, and starts cranking. If the internal combustion engine 1 cannot be started even when the fuel injection amount control map is switched in the direction of increasing and decreasing map number order, a warning display device mounted on the vehicle will display a warning that the internal combustion engine cannot be started.

[0047] Although the embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments, and various design modifications are possible without departing from the spirit of the present invention. It goes without saying that the present invention includes vehicles, internal combustion engines, and the like implemented in various forms within the spirit of the present invention. [Explanation of symbols]

[0048] 1...internal combustion engine, 5...fuel tank, 7...fuel injection device, M1...first fuel injection amount control map, M2...second fuel injection amount control map, M3...third fuel injection amount control map, M4...fourth fuel injection amount control map.

Claims

1. The present invention is used in an internal combustion engine (1) that can use alcohol, gasoline, or a mixture of alcohol and gasoline as fuel, a fuel tank (5) for storing any of the fuels; a fuel injection device (7) that supplies fuel stored in the fuel tank (5) to the internal combustion engine (1); A fuel injection control device for an internal combustion engine that controls a fuel injection amount of the fuel injection device (7) in accordance with an alcohol concentration of the fuel, Three or more fuel injection amount control maps (M) for controlling the fuel injection amount of the internal combustion engine (1) according to the range of the alcohol concentration of the fuel 1 ,M 2 ,M 3 ,M 4 ) and The plurality of fuel injection amount control maps (M 1 ,M 2 ,M 3 ,M 4 ) are assigned map numbers in order from low to high corresponding alcohol concentrations, The plurality of fuel injection amount control maps (M 1 ,M 2 ,M 3 ,M 4 ) is a selected fuel injection amount control map (M Ｓ ) adjacent fuel injection amount control maps in the order of map numbers (M S+1 ,M S-1 ) is configured to be able to start the internal combustion engine (1) based on the alcohol concentration of the fuel, When the internal combustion engine (1) is stopped, a fuel injection amount control map (M ｘ ) and When the internal combustion engine (1) is started, the immediately before-stop fuel injection amount control map (M ｘ ) to the selected fuel injection amount control map (M S )year, The selected fuel injection amount control map (M S ) the internal combustion engine (1) is started with a fuel injection amount based on When it is determined that the internal combustion engine (1) is in a start-up failure, the selected fuel injection amount control map (M ｓ ) is calculated based on the selected fuel injection amount control map (M S ) adjacent fuel injection amount control maps in the order of map numbers (M S+1 ,M S-1 ) and the fuel injection amount control map (M S+2 ,M S-2 ) to start the internal combustion engine (1).

2. The fuel injection amount control map (M 1 ,M 2 ,M 3 ,M 4 2. A fuel injection control device for an internal combustion engine according to claim 1, wherein the number of the first and second control members is four.

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