Control device

Abstract

To provide a control device capable of determining injection timing of fuel containing alcohol.SOLUTION: A control device is for an internal combustion engine. The internal combustion engine includes a body, a piston, an injector, a temperature sensor and an alcohol concentration sensor. The body includes a combustion chamber and a cylinder space. The piston reciprocates in the cylinder space. The injector injects fuel containing alcohol to the combustion chamber. The temperature sensor detects a temperature related to a temperature of an internal combustion engine. The alcohol concentration sensor detects an alcohol concentration of the fuel. When the temperature detected by the temperature sensor is lower than a predetermined temperature and / or when the alcohol concentration of the fuel detected by the alcohol concentration sensor is higher than a predetermined concentration, the control device causes the injector to inject the fuel at timing when the piston is located in the vicinity of a bottom dead center in an intake stroke.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a control device for an internal combustion engine. [Background technology]

[0002] Known examples of conventional inventions relating to control devices include a fuel injection control device described in Patent Document 1 and an internal combustion engine described in Patent Document 2. In the fuel injection control device described in Patent Document 1 and the internal combustion engine described in Patent Document 2, alcohol-blended fuel is directly injected into the combustion chamber as fuel.

[0003] In the fuel injection control device described in Patent Document 1 and the internal combustion engine described in Patent Document 2, when the alcohol concentration of the fuel is high, the injector injects fuel before the bottom dead center of the piston during the intake stroke. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2008-255907 [Patent Document 2] Japanese Patent Application Laid-Open No. 2009-047055 Summary of the Invention [Problem to be solved by the invention]

[0005] However, before the piston reaches bottom dead center during the intake stroke, the volume of the combustion chamber and the cylinder space are small. When the injector injects fuel at this time, the fuel tends to adhere to the inner surfaces of the piston head and cylinder block. Since fuel containing alcohol is difficult to vaporize, it passes through the piston rings and reaches the space under the piston. As a result, the engine oil is diluted by the fuel.

[0006] SUMMARY OF THE INVENTION It is therefore an object of the present invention to provide a control device that can prevent engine oil from being diluted by fuel. [Means for solving the problem]

[0007] A first aspect of the present invention is A control device for an internal combustion engine, the internal combustion engine includes a main body, a piston, an injector, a temperature sensor, and an alcohol concentration sensor; The main body is provided with a combustion chamber and a cylinder space, The piston reciprocates within the cylinder space, The injector injects fuel containing alcohol into the combustion chamber, the temperature sensor detects a temperature related to a temperature of the internal combustion engine; the alcohol concentration sensor detects the alcohol concentration of the fuel; the control device causes the injector to inject the fuel when the piston is positioned near bottom dead center during the intake stroke, when the temperature detected by the temperature sensor is lower than a predetermined temperature and / or when the alcohol concentration of the fuel detected by the alcohol concentration sensor is higher than a predetermined concentration. It is a control device.

[0008] A second aspect of the present invention is A control device for an internal combustion engine, the internal combustion engine includes a main body, a piston, an injector, a temperature sensor, and an alcohol concentration sensor; The main body is provided with a combustion chamber and a cylinder space, The piston reciprocates within the cylinder space, The injector injects fuel containing alcohol into the combustion chamber, the temperature sensor detects a temperature related to a temperature of the internal combustion engine; the alcohol concentration sensor detects the alcohol concentration of the fuel; the control device causes the injector to inject the fuel at injection timing A during an intake stroke when the temperature detected by the temperature sensor is lower than a predetermined temperature and the alcohol concentration of the fuel is higher than a predetermined concentration; the control device causes the injector to inject the fuel at injection timing B during the intake stroke when the temperature detected by the temperature sensor is lower than a predetermined temperature and when the alcohol concentration of the fuel is lower than a predetermined concentration; an interval between the time when the piston is at the bottom dead center during the intake stroke and the injection time A is shorter than an interval between the time when the piston is at the bottom dead center during the intake stroke and the injection time B; It is a control device. [Effects of the Invention]

[0009] According to the present invention, engine oil can be prevented from being diluted by fuel. [Brief explanation of the drawings]

[0010] [Figure 1] FIG. 1 is a schematic diagram of an internal combustion engine 10 . [Figure 2] FIG. 2 is a table showing the relationship between the water temperature, the number of injections, the injection timing, and the injection ratio. [Figure 3] FIG. 3 is a table showing the relationship between the water temperature, the number of injections, the injection timing, and the injection ratio. [Figure 4] FIG. 4 is a graph showing the relationship between A / F and time immediately after the internal combustion engine 10 is started. [Figure 5] FIG. 5 is a graph showing the relationship between A / F and time after the operation of the internal combustion engine 10 has stabilized. [Figure 6] FIG. 6 is a graph showing the relationship between the A / F improvement rate and the water temperature when the water temperature is between -5°C and 5°C. [Figure 7] FIG. 7 is a graph showing the relationship between the A / F improvement rate and the water temperature when the water temperature is between 5°C and 35°C. [Figure 8] FIG. 8 is a flowchart executed by the control device 100. DETAILED DESCRIPTION OF THE INVENTION

[0011] (Embodiment) [Structure of an internal combustion engine]

[0012] The structure of an internal combustion engine 10 according to one embodiment of the present invention will be described below with reference to the drawings.

[0013] 1 and 2, the directions in which the piston 18 moves are defined as the upward and downward directions. However, the upward and downward directions in this specification are defined for the convenience of explanation and may not coincide with the upward and downward directions when the internal combustion engine 10 is actually used.

[0014] The internal combustion engine 10 is used, for example, as a power source for an automobile. The internal combustion engine 10 is, for example, a four-stroke engine. The fuel for the internal combustion engine 10 contains alcohol. The fuel for the internal combustion engine 10 is a mixture of gasoline and alcohol, or alcohol itself. Note that although the internal combustion engine 10 in FIG. 1 is an engine with one cylinder, it is generally an engine with multiple cylinders. When the internal combustion engine 10 is an engine with multiple cylinders, the multiple cylinders may be arranged in a single row, two rows, or four rows. The internal combustion engine 10 includes a main body 12, a crankshaft 14, a connecting rod 16, a piston 18, an intake valve 20, a camshaft 21, an exhaust valve 22, a camshaft 23, an ignition plug 24, and an injector 29.

[0015] The main body 12 is provided with a combustion chamber Sp and a cylinder space Sy. The main body 12 includes a cylinder block 12a, a cylinder head 12b, and a crankcase 12c. The cylinder block 12a is provided with the cylinder space Sy. The cylinder space Sy has a cylindrical shape with a central axis extending along the vertical axis.

[0016] The cylinder head 12b is located above the cylinder block 12a. The cylinder head 12b is fixed to the cylinder block 12a. The cylinder head 12b is provided with a combustion chamber Sp. The combustion chamber Sp is located above the cylinder space Sy. The combustion chamber Sp is connected to the cylinder space Sy.

[0017] The cylinder head 12b is provided with an intake port p1 and an exhaust port p2. The intake port p1 and the exhaust port p2 are connected to the combustion chamber Sp. The intake port p1 is a part of the intake path R1. The intake path R1 is a path through which air passes. The exhaust port p2 is a part of the exhaust path R2. The exhaust path R2 is a path through which exhaust gas passes. In this way, the internal combustion engine 10 is provided with the combustion chamber Sp, the intake path R1 connected to the combustion chamber Sp, and the exhaust path R2.

[0018] The injector 29 is fixed to the cylinder head 12b. The injector 29 injects fuel containing alcohol into the combustion chamber Sp. Therefore, the internal combustion engine 10 is a direct injection engine for a FFV (Flexible Fuel Vehicle).

[0019] The crankcase 12c is located below the cylinder block 12a and is fixed to the cylinder block 12a.

[0020] The crankshaft 14 is supported by the cylinder block 12a and the crankcase 12c. The crankshaft 14 can rotate about a rotation axis that is perpendicular to the vertical axis. The piston 18 is located in the cylinder space Sy. The piston 18 has a cylindrical shape.

[0021] The connecting rod 16 connects the crankshaft 14 and the piston 18. As a result, when the crankshaft 14 rotates, the piston 18 moves up and down. In this way, the piston 18 reciprocates within the cylinder space. As shown in FIG. 1, the combustion chamber Sp is a space surrounded by the piston 18 and the cylinder head 12b when the piston 18 is at top dead center.

[0022] The intake valve 20 is supported by the cylinder head 12b. The intake valve 20 opens and closes an intake port p1 connected to the combustion chamber Sp. When the intake valve 20 opens the intake port p1, air flows into the combustion chamber Sp from the intake path R1. The camshaft 21 is rotated by the crankshaft 14. The camshaft 21 operates the intake valve 20.

[0023] The exhaust valve 22 is supported by the cylinder head 12b. The exhaust valve 22 opens and closes an exhaust port p2 that connects to the combustion chamber Sp. When the exhaust valve 22 opens the exhaust port p2, exhaust gas flows from the combustion chamber Sp into the exhaust path R2. The camshaft 23 is rotated by the crankshaft 14. The camshaft 23 operates the exhaust valve 22.

[0024] The spark plug 24 is fixed to the cylinder head 12b. The spark plug 24 includes a center electrode and a ground electrode. The center electrode and the ground electrode are exposed to the combustion chamber Sp. A high voltage is applied between the center electrode and the ground electrode of the spark plug 24 by an ignition coil (not shown). This generates a spark between the center electrode and the ground electrode of the spark plug 24, igniting the fuel in the combustion chamber Sp.

[0025] The internal combustion engine 10 further includes a control device 100 , a temperature sensor 102 and an alcohol concentration sensor 104 .

[0026] The temperature sensor 102 detects a temperature related to the temperature of the internal combustion engine 10. In this embodiment, the temperature related to the temperature of the internal combustion engine 10 is the temperature of the cooling water (hereinafter referred to as the water temperature) of the internal combustion engine 10. Therefore, the temperature sensor 102 is provided in a pipe through which the cooling water passes.

[0027] The alcohol concentration sensor 104 is provided in a pipe that connects the fuel tank and the injector. The alcohol concentration sensor 104 detects the alcohol concentration of the fuel.

[0028] The control device 100 is an ECU (Engine Control Unit). The control device 100 controls the timing at which the injector 29 injects fuel based on the temperature detected by the temperature sensor 102 and the alcohol concentration detected by the alcohol concentration sensor 104.

[0029] [Operation of the control device 100] Next, the operation of the control device 100 will be described with reference to the drawings. Figures 2 and 3 are tables showing the relationship between water temperature, the number of injections, the injection timing, and the injection ratio. Figure 2 is a table when a fuel containing 100% ethanol is used. Figure 3 is a table when a fuel containing 22% ethanol and 78% gasoline is used.

[0030] 2 and 3 means that fuel is injected at a time X degrees before top dead center on the compression stroke. The time X degrees before top dead center on the compression stroke will be explained. The crank angle when the piston 18 is at top dead center on the compression stroke is defined as 0 degrees. X degrees before top dead center on the compression stroke is the time when the crank angle is X degrees earlier than the time when the crank angle is 0 degrees on the compression stroke.

[0031] Also, the injection timing is indicated by a series of numbers, such as 180 / 5. This means that the first injection is 180° before top dead center on the compression stroke, and the second injection is 5° before top dead center on the compression stroke.

[0032] In direct injection engines, the injector typically injects fuel during the intake stroke. However, when the injector injects fuel containing alcohol, if the fuel is injected early in the intake stroke, the engine oil is diluted by the fuel, as explained below. An example of an early period in the intake stroke is 300 degrees before top dead center on the compression stroke. The combined volume of the combustion chamber and the cylinder space is small early in the intake stroke. Therefore, the fuel is likely to adhere to the inner surfaces of the piston head and cylinder block.

[0033] Here, the fuel contains alcohol. Alcohol is less likely to vaporize than gasoline. Therefore, when the temperature of the internal combustion engine 10 is low (hereinafter referred to as the low-temperature state), if fuel containing alcohol adheres to the inner surface of the piston head or cylinder block, the fuel does not vaporize and remains in the combustion chamber and cylinder space. In Figures 2 and 3, the low-temperature state means a state in which the water temperature of the internal combustion engine 10 is 35°C or lower when the internal combustion engine 10 is started, and a state in which the water temperature of the internal combustion engine 10 is 30°C or lower when the internal combustion engine 10 is under normal control. The fuel remaining in the combustion chamber and cylinder space passes through the piston ring and moves below the piston. As a result, the engine oil is diluted with the fuel.

[0034] Furthermore, at low temperatures, fuel containing alcohol is difficult to atomize. Therefore, the control device injects more fuel into the injector. This keeps the air-fuel ratio of the mixture at a value suitable for combustion. However, more fuel containing alcohol adheres to the inner surfaces of the piston head and cylinder block, further accelerating the dilution of engine oil with the fuel.

[0035] Therefore, as shown in FIG. 2 during normal control (-5°C to 30°C), when the temperature detected by the temperature sensor 102 is lower than a predetermined temperature and the alcohol concentration of the fuel detected by the alcohol concentration sensor is higher than a predetermined concentration (hereinafter referred to as a low-temperature, high-concentration state), the control device 100 causes the injector 29 to perform two injections. In the first injection, the control device 100 causes the injector 29 to inject fuel when the piston 18 is located near bottom dead center during the intake stroke. The range near bottom dead center is from 210° before top dead center to 180° before top dead center during the compression stroke. In this embodiment, the control device 100 causes the injector 29 to inject fuel at 180° before top dead center (injection timing A) during the compression stroke. When the piston 18 is located near bottom dead center, the sum of the volumes of the combustion chamber Sp and the cylinder space Sy is large. Therefore, alcohol-containing fuel is less likely to adhere to the inner surfaces of the piston head and the cylinder block. As a result, engine oil is less likely to be diluted by the fuel. Also, premixing of air and fuel is achieved.

[0036] In the second injection, the control device 100 causes the injector 29 to inject fuel into the combustion chamber Sp at a timing around 0° before top dead center on the compression stroke. In this embodiment, the control device 100 causes the injector 29 to inject fuel at 5° or 15° before top dead center on the compression stroke. The temperature of the combustion chamber Sp becomes high around 0° before top dead center on the compression stroke. Therefore, the fuel containing alcohol is easily atomized.

[0037] As described above, the second injection of fuel containing alcohol is likely to atomize. However, the second injection alone does not provide sufficient premixing of the air-fuel mixture. This may result in combustion variations in the internal combustion engine 10. Therefore, the control device 100 injects fuel from the injector 29 during the first injection when the piston 18 is near bottom dead center during the intake stroke. This improves the premixing of the air-fuel mixture and prevents engine oil from being diluted by the fuel.

[0038] On the other hand, when the temperature detected by the temperature sensor 102 is lower than a predetermined temperature and the alcohol concentration of the fuel detected by the alcohol concentration sensor is lower than a predetermined concentration (hereinafter referred to as a low-temperature, low-concentration state), the fuel containing alcohol is more likely to vaporize than in a low-temperature, high-concentration state. Therefore, as shown in Figure 3 during normal control from -5°C to 30°C, in the first injection, the control device 100 causes the injector 29 to inject fuel before the piston 18 is positioned near bottom dead center during the intake stroke. In this embodiment, the control device 100 causes the injector 29 to inject fuel 200° before top dead center during the compression stroke (injection timing B).

[0039] Furthermore, in a low-temperature, low-concentration state, fuel containing alcohol is more easily atomized than in a low-temperature, high-concentration state. Therefore, the temperatures of the combustion chamber Sp and the cylinder space Sy do not need to be as high. Therefore, as shown in Figure 3 for the range of -5°C to 30°C during normal control, in the second injection, the control device causes the injector 29 to inject fuel 120° before top dead center on the compression stroke.

[0040] As described above, when the temperature detected by the temperature sensor 102 is lower than the predetermined temperature and the alcohol concentration of the fuel is higher than the predetermined concentration (i.e., a low-temperature, high-concentration state), the control device 100 causes the injector 29 to inject fuel at injection timing A during the intake stroke (180° before top dead center during the compression stroke). On the other hand, when the temperature detected by the temperature sensor is lower than the predetermined temperature and the alcohol concentration of the fuel is lower than the predetermined concentration (i.e., a low-temperature, low-concentration state), the control device 100 causes the injector 29 to inject fuel at injection timing B during the intake stroke (200° before top dead center during the compression stroke). The interval between the time when the piston 18 is at bottom dead center during the intake stroke and injection timing A (180° before top dead center during the compression stroke) is shorter than the interval between the time when the piston is at bottom dead center during the intake stroke and injection timing B (200° before top dead center during the compression stroke).

[0041] Here, the inventors of the present application conducted the following experiments to confirm the effects of the above control. Fig. 4 is a graph showing the relationship between A / F and time immediately after starting the internal combustion engine 10. Fig. 5 is a graph showing the relationship between A / F and time after the operation of the internal combustion engine 10 has stabilized.

[0042] The inventors of the present application conducted experiments under low-temperature, high-concentration conditions. Furthermore, in the results of FIG. 4, the A / F sensor was not operating due to the low water temperature. That is, in the results of FIG. 4, feedback control based on the output of the A / F sensor was not performed. Furthermore, in the results of FIG. 4, an external A / F sensor was used instead of the A / F sensor of the internal combustion engine 10. Meanwhile, in the results of FIG. 5, the A / F sensor was operating. That is, in the results of FIG. 5, feedback control based on the output of the A / F sensor was performed.

[0043] In Figures 4 and 5, the solid line represents the A / F when the first injection timing is 180° before top dead center. The dotted line represents the A / F when the first injection timing is 200° before top dead center. Comparing these, the solid line is slightly lower than the dotted line. In other words, the A / F when the first injection timing is 180° before top dead center is lower than the A / F when the first injection timing is 200° before top dead center. In other words, the fuel ratio when the first injection timing is 180° before top dead center is higher than the fuel ratio when the first injection timing is 200° before top dead center. This means that when the first injection timing is 180° before top dead center, the fuel is sufficiently atomized, resulting in good combustion.

[0044] The inventors of the present application also created the graphs of FIGS. 6 and 7 based on the graphs of FIGS. 4 and 5. FIG. 6 is a graph showing the relationship between the A / F improvement rate and water temperature when the water temperature is between -5° and 5°. FIG. 7 is a graph showing the relationship between the A / F improvement rate and water temperature when the water temperature is between 5° and 35°. The A / F improvement rate is the value obtained by dividing the A / F when the first injection timing is 200° before top dead center by the A / F when the first injection timing is 180° before top dead center. As a result, it can be seen that the A / F is improved in almost all temperature ranges when the first injection timing is 180° before top dead center.

[0045] Next, the operation of the control device 100 will be described with reference to the drawings. Fig. 8 is a flowchart executed by the control device 100. The control device 100 executes the flowchart of Fig. 8 by reading a program stored in a storage device (not shown).

[0046] The control device 100 determines whether the operation is during startup or normal control (step S1). Start-up operation is a state in which the engine is operated with the fuel injection amount, throttle opening, and ignition timing, which are combustion elements, at fixed values for each engine water temperature. Normal control operation is a state in which the engine is operated by feedback controlling the fuel injection amount, throttle opening, and ignition timing, which are combustion elements, mainly to achieve the target rotation speed / stoichiometric air-fuel ratio. If the operation is during startup, the process proceeds to a start-up control step. Note that the start-up control step is not a characteristic feature of this embodiment, so a description thereof will be omitted. If the operation is during normal control, the process proceeds to step S2.

[0047] Next, the control device 100 acquires information (step S2). The information is the temperature detected by the temperature sensor 102 and the alcohol concentration detected by the alcohol concentration sensor 104. Then, the control device 100 determines whether the temperature detected by the temperature sensor 102 is lower than a predetermined temperature (step S3). In step S3, the control device 100 determines whether the internal combustion engine 10 is in a low-temperature state. The predetermined temperature is, for example, 30°C. If the temperature is lower than the predetermined temperature, the process proceeds to step S4. If the temperature is not lower than the predetermined temperature, the process proceeds to step S5.

[0048] If the temperature is lower than the predetermined temperature, the control device 100 determines whether the alcohol concentration detected by the alcohol concentration sensor 104 is higher than a predetermined value (step S4). In step S4, the control device 100 determines whether the fuel is in a low concentration state. The predetermined concentration is, for example, 85%. If the alcohol concentration is higher than the predetermined value, the process proceeds to step S6. If the alcohol concentration is not higher than the predetermined value, the process proceeds to step S7.

[0049] If the alcohol concentration is higher than the predetermined value, the control device 100 determines that the operating state of the internal combustion engine 10 is a low-temperature, high-concentration state. Therefore, the control device 100 sets the timing at which the injector 29 injects fuel to the first injection timing (step S6). As shown in FIG. 2, the first injection timing is 180° before top dead center, and the second injection timing is 5° or 15° before top dead center. After this, the process proceeds to step S10.

[0050] If the alcohol concentration is lower than the predetermined value, the control device 100 determines that the state of the internal combustion engine 10 is a low-temperature, low-concentration state. Therefore, the control device 100 sets the timing at which the injector 29 injects fuel to the second injection timing (step S7). As shown in FIG. 3, the second injection timing is such that the first injection timing is 200° before top dead center and the second injection timing is 120° before top dead center. After this, the process proceeds to step S10.

[0051] If the temperature is higher than the predetermined temperature, the control device 100 determines whether the alcohol concentration detected by the alcohol concentration sensor 104 is higher than a predetermined value (step S5). In step S5, the control device 100 determines whether the fuel is in a low concentration state. The predetermined concentration is, for example, 85%. If the alcohol concentration is higher than the predetermined value, the process proceeds to step S8. If the alcohol concentration is not higher than the predetermined value, the process proceeds to step S9.

[0052] If the alcohol concentration is higher than the predetermined value, the control device 100 determines that the state of the internal combustion engine 10 is a high-temperature, high-concentration state. Therefore, the control device 100 sets the timing at which the injector 29 injects fuel to the third injection timing (step S8). As shown in FIG. 3, the third injection timing is 300° before top dead center. After this, the process proceeds to step S10.

[0053] If the alcohol concentration is lower than the predetermined value, the control device 100 determines that the internal combustion engine 10 is in a high-temperature, low-concentration state. Therefore, the control device 100 sets the timing at which the injector 29 injects fuel to a fourth injection timing (step S9). As shown in FIG. 3, the fourth injection timing is 300° before top dead center. After this, the process proceeds to step S10.

[0054] In step S10, the control device 100 determines whether or not to end this process (step S10). The control device 100 determines whether or not to end this process by determining whether or not to stop the internal combustion engine 10. If this process does not end, the process returns to step S1.

[0055] [effect] The control device 100 can prevent engine oil from being diluted by fuel. More specifically, the control device 100 causes the injector 29 to inject fuel when the piston 18 is located near bottom dead center during the intake stroke. When the piston 18 is located near bottom dead center, the sum of the volumes of the combustion chamber Sp and the cylinder space Sy is large. Therefore, fuel containing alcohol is less likely to adhere to the inner surfaces of the piston head and the cylinder block. As a result, the engine oil is less likely to be diluted by fuel. Furthermore, premixing of air and fuel is achieved.

[0056] The control device 100 can also prevent engine oil from being diluted by fuel for the following reason. More specifically, fuel in a low-temperature, high-concentration state is less likely to vaporize than fuel in a high-temperature, low-concentration state. Therefore, in a low-temperature, high-concentration state, it is preferable for the injector 29 to inject fuel when the sum of the volume of the combustion chamber Sp and the volume of the cylinder space Sy is large.

[0057] Therefore, when the temperature detected by the temperature sensor 102 is lower than a predetermined temperature and the alcohol concentration of the fuel is higher than a predetermined concentration (i.e., a low-temperature, high-concentration state), the control device 100 causes the injector 29 to inject fuel at injection timing A during the intake stroke. On the other hand, when the temperature detected by the temperature sensor 102 is lower than a predetermined temperature and the alcohol concentration of the fuel is lower than a predetermined concentration (i.e., a low-temperature, low-concentration state), the control device 100 causes the injector 29 to inject fuel at injection timing B during the intake stroke. The interval between the time when the piston 18 is at bottom dead center during the intake stroke and injection timing A is shorter than the interval between the time when the piston is at bottom dead center during the intake stroke and injection timing B. The sum of the volumes of the combustion chamber Sp and the cylinder space Sy at injection timing A, which is the injection timing in the low-temperature, high-concentration state, is greater than the sum of the volumes of the combustion chamber Sp and the cylinder space Sy at injection timing B, which is the injection timing in the low-temperature, low-concentration state. Therefore, in low-temperature, high-concentration conditions, alcohol-containing fuel is less likely to adhere to the inner surfaces of the piston head and cylinder block. As a result, engine oil is less likely to be diluted by the fuel. In addition, premixing of air and fuel is achieved.

[0058] (Other embodiments) The control device according to the present invention is not limited to the control device 100, and can be modified within the scope of the gist thereof.

[0059] The automobile may be a four-wheeled automobile, a three-wheeled automobile, or a two-wheeled automobile. A two-wheeled automobile is a leaning vehicle in which the body leans in the same direction as the direction of travel around a corner. A three-wheeled automobile may be a leaning vehicle or a vehicle that rolls in the opposite direction to the direction of travel around a corner.

[0060] Note that the injection timing in the table of Fig. 2 is listed as 15-30. This means that when the rotation speed of the internal combustion engine 10 is less than 400 rpm, fuel is injected 15 degrees before top dead center of the compression stroke, and when the rotation speed of the internal combustion engine 10 is 400 rpm or more, fuel is injected 30 degrees before top dead center of the compression stroke. When the rotation speed of the internal combustion engine 10 is less than 400 rpm, not much time has passed since the start of combustion, so fuel is injected at a timing when the temperature of the combustion chamber Sp is high. On the other hand, when the rotation speed of the internal combustion engine 10 is 400 rpm or more, the rotation speed is increasing, so fuel is injected at a timing when premixing is easily achieved.

[0061] The temperature sensor 102 may detect a temperature related to the temperature of the internal combustion engine 10. Therefore, the temperature sensor 102 may detect a temperature other than the water temperature of the internal combustion engine 10. The temperature other than the water temperature of the internal combustion engine 10 is, for example, the oil temperature of the internal combustion engine 10.

[0062] In addition, when the temperature detected by the temperature sensor 102 is lower than a predetermined temperature, or when the alcohol concentration of the fuel detected by the alcohol concentration sensor 104 is higher than a predetermined concentration, the control device 100 may cause the injector 29 to inject fuel when the piston is located near bottom dead center during the intake stroke. [Explanation of symbols]

[0063] 10: Internal combustion engine 12:Main body 18: Piston 20: Intake valve 21,23: Camshaft 22: Exhaust valve 29: Injector 100: Control device 102: Temperature sensor 104: Alcohol concentration sensor R1: Intake path R2: Exhaust route Sp: Combustion chamber Sy: Cylinder space p1: Intake port p2: Exhaust port

Claims

1. A control device for an internal combustion engine, the internal combustion engine includes a main body, a piston, an injector, a temperature sensor, and an alcohol concentration sensor; The main body is provided with a combustion chamber and a cylinder space, The piston reciprocates within the cylinder space, The injector injects fuel containing alcohol into the combustion chamber, the temperature sensor detects a temperature related to a temperature of the internal combustion engine; the alcohol concentration sensor detects the alcohol concentration of the fuel; the control device causes the injector to inject the fuel when the piston is positioned near bottom dead center during the intake stroke, when the temperature detected by the temperature sensor is lower than a predetermined temperature and / or when the alcohol concentration of the fuel detected by the alcohol concentration sensor is higher than a predetermined concentration. Control device.

2. A control device for an internal combustion engine, the internal combustion engine includes a main body, a piston, an injector, a temperature sensor, and an alcohol concentration sensor; The main body is provided with a combustion chamber and a cylinder space, The piston reciprocates within the cylinder space, The injector injects fuel containing alcohol into the combustion chamber, the temperature sensor detects a temperature related to a temperature of the internal combustion engine; the alcohol concentration sensor detects the alcohol concentration of the fuel; the control device causes the injector to inject the fuel at an injection timing A during an intake stroke when the temperature detected by the temperature sensor is lower than a predetermined temperature and when the alcohol concentration of the fuel is higher than a predetermined concentration; the control device causes the injector to inject the fuel at injection timing B during the intake stroke when the temperature detected by the temperature sensor is lower than a predetermined temperature and when the alcohol concentration of the fuel is lower than a predetermined concentration; an interval between the time when the piston is at the bottom dead center during the intake stroke and the injection time A is shorter than an interval between the time when the piston is at the bottom dead center during the intake stroke and the injection time B; Control device.

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