Vehicle control system

Abstract

This vehicle control system comprises: an internal combustion engine mounted in a vehicle; a first fuel injector for injecting fuel into an intake port of the internal combustion engine; a second fuel injector for injecting the fuel into a cylinder of the internal combustion engine; an external power supply device for supplying power to an apparatus outside the vehicle; a generator driven by the internal combustion engine; and a control device for controlling the vehicle. The control device executes second fuel injection if the internal combustion engine is activated to generate power during the operation of the external power supply device.

Description

Vehicle Control Systems

[0001] The present disclosure relates to a control system for a vehicle.

[0002] Conventionally, a vehicle control system that uses an engine to drive a generator is known (see, for example, Patent Document 1). In the vehicle control system of Patent Document 1, the generated electric power is used to supply power to external devices of the vehicle.

[0003] Japanese Patent Application Publication No. 2013-51772

[0004] The requirements for an engine differ between when an engine drives a generator and supplies the generated power to external devices of the vehicle and when an engine drives a generator and uses the generated power to propel the vehicle. For example, when an engine drives a generator and supplies the generated power to external devices of the vehicle, such as when using a vehicle to use home appliances while camping, the user is likely not near the vehicle, so there is little need to suppress engine noise. On the other hand, when an engine drives a generator and uses the generated power to propel the vehicle, the user is in the vehicle, so there is a strong need to suppress engine noise. However, in both cases, it is preferable to minimize fuel consumption during power generation. Patent Document 1 does not disclose a method for suppressing fuel consumption when an engine drives a generator and supplies the generated power to external devices of the vehicle.

[0005] An object of the present disclosure is to provide a vehicle control system that can reduce fuel consumption during power generation.

[0006] The vehicle control system according to the present disclosure includes an internal combustion engine mounted on a vehicle, a first fuel injection device that injects fuel into an intake port of the internal combustion engine, a second fuel injection device that injects fuel into a cylinder of the internal combustion engine, an external power supply device that supplies power to equipment outside the vehicle, a generator driven by the internal combustion engine, and a control device that controls the vehicle, wherein the control device executes the second fuel injection when the internal combustion engine is operated to generate power while the external power supply device is in operation.

[0007] According to this vehicle control system, by performing the second fuel injection that injects fuel into the cylinders while the external power supply device is operating, the internal combustion engine can be operated efficiently under high load, thereby reducing fuel consumption.

[0008] 1 is a flowchart illustrating a control procedure executed by a control device according to a first embodiment of the present disclosure;

[0009] First Embodiment A first embodiment of the present disclosure will be described below with reference to the drawings.

[0010] 1 and 2 , a control system 1 of a vehicle C includes an engine (an example of an internal combustion engine) 2, a motor (FrM) 3, a generator (GEN) 4, a drive battery (BT) 6, a transaxle 8, an inverter 12 that controls the motor 3 and the generator 4, an accelerator pedal 14 operated by a user of the vehicle C, a charger 16 that can be connected to an external power source, an external power supply device 18 that can supply power to external devices such as home appliances, a vehicle control device (an example of a control device) 20, an engine control device 22 that controls the engine 2, a fuel tank (FUEL TANK) 24, and a user detection device 26. In addition, the vehicle C may include, for example, a charge button (not shown) that the user uses to instruct charging. The vehicle C of this embodiment is a plug-in hybrid electric vehicle (PHEV) equipped with external charging, which allows power from an external power source to be stored in the drive battery 6 by a charger 16, and external power feeding, which allows power from the drive battery 6 to be supplied to external devices by an external power feeding device 18.

[0011] As shown in Figure 1, the engine 2 is connected to and drives a generator 4. Furthermore, in this embodiment, the engine 2 is capable of driving wheels C1 via a transaxle 8. The engine 2 in this embodiment is an in-line four-cylinder gasoline engine. The engine 2 receives fuel from a fuel tank 24 and burns and consumes the fuel.

[0012] As shown in FIG. 2 , the engine 2 includes a first fuel injection valve 30, a second fuel injection valve 32, an exhaust gas purification device 42, and a water temperature detection device 44. The first fuel injection valve 30 performs port injection (MPI in FIG. 3 , an example of first fuel injection) that injects fuel into an intake port 34 of the engine 2. The second fuel injection valve 32 performs in-cylinder injection (DI in FIG. 3 , an example of second fuel injection) that injects fuel into a cylinder 36 of the engine 2. The second fuel injection valve 32 receives fuel pressurized by a high-pressure pump 38. The high-pressure pump 38 is driven, for example, by a cam 40. The first fuel injection valve 30, the second fuel injection valve 32, and the high-pressure pump 38 are electrically connected to the engine control device 22. In normal injection, the engine control device 22 operates the engine 2 while maintaining a predetermined injection ratio between port injection and in-cylinder injection depending on the load and rotation speed of the engine 2.

[0013] The exhaust purification device 42 is a device that purifies the exhaust gas from the engine 2. The exhaust purification device 42 may include a front catalytic converter 42a and an underfloor catalytic converter 42b. The exhaust purification device 42 requires warming up. The exhaust purification device 42 detects the state of exhaust gas purification using a plurality of sensors (e.g., oxygen sensors or air-fuel ratio sensors) 42c. The plurality of sensors 42c are electrically connected to the engine control device 22.

[0014] The water temperature detection device 44 is a water temperature sensor that detects the temperature of the cooling water that cools the engine 2. The water temperature detection device 44 is electrically connected to the engine control device 22.

[0015] As shown in FIG. 1 , the motor 3 is connected to the wheels C1 via a transaxle 8 and an axle 10 to drive the wheels C1. In this embodiment, the motor 3 is a three-phase AC motor having multiple coils and multiple permanent magnets. The motor 3 is driven by the rotation of the axle 10 (wheels C1) to generate electricity (regenerate). Therefore, the motor 3 is a motor-generator capable of power running and generating electricity. The generator 4 is connected to the engine 2 and is capable of driving the engine 2. The generator 4 performs motoring, driving the engine 2, while power running is performed using electric power from the drive battery 6. Meanwhile, the generator 4 is driven by the engine 2 to generate electricity while the engine 2 is operating. Therefore, the generator 4 is a motor-generator capable of power running and generating electricity.

[0016] The drive battery 6 outputs electric power to the motor 3 and the generator 4, and also receives electric power generated by the motor 3 and the generator 4. Furthermore, the drive battery 6 receives external electric power via a charger 16. In this embodiment, the drive battery 6 is made up of multiple lithium-ion batteries.

[0017] The transaxle 8 has a plurality of gears and a clutch 8a. The engine 2 is connected to the generator 4 and the axle 10 via the transaxle 8. When the clutch 8a is in a disengaged state, the transaxle 8 cuts off the power transmission between the engine 2 and the axle 10, and when the clutch 8a is in a engaged state, the power of the engine 2 is transmitted to the axle 10.

[0018] The inverter 12 converts the DC power supplied from the drive battery 6 into AC power and adjusts the power supplied to the motor 3, thereby controlling the power running torque of the motor 3. When the motor 3 regenerates electricity, the inverter 12 converts the AC power supplied from the motor 3 into DC power and adjusts the power supplied to the drive battery 6, thereby controlling the regenerative torque of the motor 3.

[0019] The vehicle control device 20 is electrically connected to the motor 3 via the inverter 12 and controls the motor 3. The vehicle control device 20 is actually an ECU (Electronic Control Unit) configured by a microcomputer including a calculation device, a memory, an input / output buffer, etc. The vehicle control device 20 controls the vehicle C based on maps and programs stored in the memory.

[0020] The vehicle control device 20 of this embodiment is further electrically connected to an engine control device 22. The engine control device 22 is electrically connected to various devices provided in the engine 2 and controls the engine 2. The control of the engine 2 may be performed by the vehicle control device 20 in addition to the engine control device 22. The vehicle control device 20 may also be electrically connected to various other devices of the vehicle C and perform various controls.

[0021] The vehicle C of this embodiment has driving modes such as EV mode, series mode, and parallel mode. In EV mode, the vehicle C drives the motor 3 with power from the drive battery 6 while the engine 2 is stopped. In series mode, the vehicle C disengages the clutch 8a, drives the generator 4 with the engine 2, and uses the power generated by the generator 4 to drive the motor 3 and drive wheels (an example of drive wheels) C1. In parallel mode, the vehicle C engages the clutch 8a, and uses power from the engine 2 to drive the wheels C1 via the axle 10. In the vehicle C, the vehicle control device 20 switches between each driving mode depending on the depression state of the accelerator pedal 14, controls the motor 3 and the generator 4 via the inverter 12, and causes the engine control device 22 to control the engine 2.

[0022] Furthermore, the vehicle C of this embodiment has an external power supply mode. In the external power supply mode, when the connector 18a is connected to an external device, the vehicle control device 20 supplies power from the drive battery 6 to the external device using the external power supply device 18. When the state of charge (SOC) of the drive battery 6 falls below a predetermined state of charge SOCt during the external power supply mode, the vehicle control device 20 executes an engine power generation external power supply mode (an example of a power generation mode) in which the clutch 8a is disengaged, the engine 2 is started to drive the generator 4, and the power generated by the generator 4 is stored in the drive battery 6 and supplied to the external device.

[0023] The user detection device 26 is a device that can detect the presence of a user inside or near the vehicle C. In this embodiment, the user detection device 26 is a camera that can capture images inside and outside the vehicle C.

[0024] Next, a control procedure executed by the vehicle control device 20 will be described with reference to the flowchart of Fig. 3. In the first embodiment, the vehicle control device 20 starts the control procedure when the connector 18a is connected to an external device.

[0025] In step S1, the vehicle control device 20 determines whether the vehicle is in the engine-power-generation external power supply mode. If the vehicle control device 20 determines that the vehicle is in the engine-power-generation external power supply mode (YES in step S1), the vehicle control device 20 proceeds to step S2. If the vehicle control device 20 determines that the vehicle is not in the engine-power-generation external power supply mode (NO in step S1), the vehicle control device 20 returns to the main control. Note that when external power supply is terminated (for example, when the connector 18a is removed from the external device), the main control flow ends.

[0026] In step S2, the vehicle control device 20 performs in-cylinder injection (second fuel injection). That is, the injection amount of in-cylinder injection is set to 100%, and the injection amount of port injection is set to 0%. In-cylinder injection injects fuel directly into the cylinder 36, making it possible to suppress knocking by utilizing the heat of vaporization of the fuel, resulting in better combustion efficiency and fuel economy than port injection. However, during in-cylinder injection, the high-pressure pump 38 operates, making the engine 2 noisy. In the external power supply mode, the user is often not in the vehicle, so the user is more likely to tolerate the engine 2 making a loud noise. After performing in-cylinder injection, the vehicle control device 20 proceeds to step S3.

[0027] In step S3, the vehicle control device 20 determines whether the power supplied to the external power supply device 18 (hereinafter sometimes referred to as first power) is equal to or less than a predetermined power. If the vehicle control device 20 determines that the power is equal to or less than the predetermined power (YES in step S3), the vehicle control device 20 proceeds to step S8. In step S8, the vehicle control device 20 reduces the injection amount of the in-cylinder injection and increases the injection amount of the port injection.

[0028] The predetermined power is, for example, the power generated by driving the engine 2 at an output that results in the minimum injection quantity of the second fuel injection valve 32. When the external power supply device 18 supplies the first power to an external device, the first power is taken from the drive battery. The vehicle control device 20 generates the first power in the power generation mode and charges the drive battery 6. At this time, the vehicle control device 20 stores the engine 2 rotational speed that provides the most fuel-efficient operation in the power generation mode and operates the engine 2 at this rotational speed. This enables power generation with good fuel efficiency, balances the charge and take-out amounts of the drive battery 6, and tends to maintain the performance of the drive battery 6. However, if the first power falls below the predetermined power (e.g., 5 kW), the vehicle control device 20 reduces the engine 2 rotational speed. However, if the engine 2 rotational speed is below the predetermined rotational speed (e.g., 1000 rpm), the engine 2 cannot be operated using the second fuel injection valve 32 because the rotational speed falls below the minimum injection quantity of the second fuel injection valve 32. The electric power required for the engine 2 to reach the predetermined rotational speed is the predetermined electric power. In this case, the vehicle control device 20 can increase the port injection amount to operate the engine 2 while maintaining the injection amount of the second fuel injection valve 32 at the minimum injection amount. This allows the engine 2 to continue operating at a rotational speed below the predetermined rotational speed. In this embodiment, in step S8, the injection amount of the in-cylinder injection is set to 0% and the injection amount of the port injection is set to 100%, but this is not limiting. For example, the injection amount of the in-cylinder injection may be set to 20% and the injection amount of the port injection to 80%. If the vehicle control device 20 determines that the electric power supplied to the external power supply device 18 is greater than the predetermined electric power (NO in step S3), the vehicle control device 20 proceeds to step S4.

[0029] In step S4, the vehicle control device 20 determines whether or not the warm-up of the exhaust purification device 42 is complete. If the vehicle control device 20 determines that the warm-up of the exhaust purification device 42 is not complete (NO in step S4), the vehicle control device 20 proceeds to step S8. In step S8, the vehicle control device 20 reduces the injection amount of the in-cylinder injection and increases the injection amount of the port injection.

[0030] In this way, when the vehicle control device 20 executes the power generation mode before warm-up is complete, it reduces the injection amount of the in-cylinder injection and increases the injection amount of the port injection to operate the engine 2 and complete the warm-up of the exhaust purification device 42. Because the generated power can be supplied to external devices during the power generation mode, the engine 2 can generally be operated at a relatively high load, and the in-cylinder injection is unlikely to deteriorate exhaust gas. However, when warming up the exhaust purification device 42 is performed in a situation such as a sudden decrease in power consumption of the external devices, there is a risk that the in-cylinder injection spray will remain unburned, resulting in an increase in unburned hydrocarbons. Therefore, the vehicle control device 20 increases the injection amount of the port injection to suppress the generation of unburned hydrocarbons. This allows the warm-up of the exhaust purification device to continue while suppressing deterioration of exhaust gas quality. If the vehicle control device 20 determines that warm-up of the exhaust purification device 42 is complete (YES in step S4), the vehicle control device 20 proceeds to step S5.

[0031] In step S5, the vehicle control device 20 determines whether the coolant temperature is equal to or lower than a predetermined temperature. If the vehicle control device 20 determines that the coolant temperature is equal to or lower than the predetermined temperature (YES in step S5), the vehicle control device 20 proceeds to step S8. In step S8, the vehicle control device 20 reduces the injection amount of in-cylinder injection and increases the injection amount of port injection. The predetermined temperature is the temperature at which the warm-up of the engine 2 is completed, for example, a coolant temperature of 80°C.

[0032] Before the warm-up of the engine 2 is complete, atomization of fuel by in-cylinder injection is poor, and unburned hydrocarbons are likely to be generated. Therefore, the vehicle control device 20 increases the injection amount of port injection to suppress the generation of unburned hydrocarbons. If the vehicle control device 20 determines that the temperature of the cooling water is higher than the predetermined water temperature (NO in step S5), the vehicle control device 20 proceeds to step S6.

[0033] In step S6, the vehicle control device 20 determines whether or not a user has been detected. The vehicle control device 20 may determine that a user has been detected if an image of the user is captured by the camera of the user detection device 26. If the vehicle control device 20 determines that a user has been detected (YES in step S6), the vehicle control device 20 proceeds to step S8. In step S8, the vehicle control device 20 reduces the injection amount of in-cylinder injection and increases the injection amount of port injection.

[0034] It is preferable to suppress the noise of the engine 2 when the user is inside the vehicle C or near the vehicle C. When the vehicle control device 20 detects the user, it increases the injection amount of the port injection to suppress the operating noise of the high-pressure pump 38. When the vehicle control device 20 determines that the user is not present (NO in step S6), the vehicle control device 20 proceeds to step S1.

[0035] As described above, according to the present disclosure, it is possible to provide a control system 1 for a vehicle C that can reduce fuel consumption.

[0036] Although the embodiments of the present disclosure have been described above, the present disclosure is not limited to the above-described embodiments, and various modifications are possible without departing from the spirit of the invention. In particular, the multiple modifications described in this specification can be combined as needed.

[0037] (a) In the above embodiment, the series mode has been described as an example of the power generation mode, but the present disclosure is not limited to this. The power generation mode may be any mode as long as the engine 2 drives the generator 4 to generate electricity.

[0038] (b) In the above embodiment, the vehicle C is described as a plug-in hybrid vehicle, but the present disclosure is not limited to this. The vehicle C may be a hybrid vehicle that does not have a charger 16 and cannot be externally charged.

[0039] (c) The user detection device 26 does not have to be a camera. For example, an electronic key for vehicle C may be used, and if communication with the electronic key is possible, it may be determined that the presence of a user has been detected in or near vehicle C. Alternatively, the presence of a user in the passenger compartment of vehicle C may be detected by a pressure sensor provided in the seat cushion of vehicle C.

[0040] This application is based on a Japanese patent application (Patent Application No. 2024-43060) filed on March 19, 2024, the contents of which are incorporated herein by reference.

[0041] According to the present invention, it is possible to provide a vehicle control system that can reduce fuel consumption. The present invention that achieves this effect is useful for vehicle control systems.

[0042] 1: Control system, 2: Engine, 4: Generator, 6: Drive battery, 18: External power supply device, 20: Vehicle control device, 30: First fuel injection valve, 32: Second fuel injection valve, 26: User detection device, 42: Exhaust gas purification device, 44: Water temperature detection device, C: Vehicle

Claims

1. A vehicle control system comprising: an internal combustion engine mounted on a vehicle; a first fuel injection that injects fuel into an intake port of the internal combustion engine; a second fuel injection that injects fuel into a cylinder of the internal combustion engine; an external power supply device that supplies power to equipment outside the vehicle; a generator driven by the internal combustion engine; and a control device that controls the vehicle, wherein the control device executes the second fuel injection when the vehicle is in a power generation mode in which the internal combustion engine is operated to generate power while the external power supply device is in operation.

2. The vehicle control system according to claim 1, wherein, in the power generation mode, when the power supplied to the external power supply device is equal to or less than a predetermined power, the control device reduces the injection amount of the second fuel injection and increases the injection amount of the first fuel injection compared to when the power supplied to the external power supply device exceeds the predetermined power.

3. A vehicle control system as described in claim 1, further comprising an exhaust purification device that purifies the exhaust of the internal combustion engine, wherein in the power generation mode, when the exhaust purification device has not yet been warmed up, the control device reduces the injection amount of the second fuel injection and increases the injection amount of the first fuel injection compared to after the exhaust purification device has been warmed up.

4. A vehicle control system as described in claim 1, further comprising a user detection device that detects a user of the vehicle, wherein when the control device detects the user in the power generation mode, the control device reduces the injection amount of the second fuel injection and increases the injection amount of the first fuel injection compared to when the user is not detected.

5. A vehicle control system according to any one of claims 1 to 4, further comprising a water temperature detection device that detects the temperature of the cooling water of the internal combustion engine, wherein the control device, in the power generation mode, when the temperature of the cooling water is below a predetermined temperature, reduces the injection amount of the second fuel injection and increases the injection amount of the first fuel injection compared to when the temperature of the cooling water exceeds the predetermined temperature.

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