Vehicle control method and vehicle control device

Abstract

The present invention provides a vehicle control method and a vehicle control device that, in a hybrid vehicle, can shorten the battery charging time while ensuring sufficient driving force to keep the vehicle moving, even when there is a demand for battery charging while the vehicle is in motion. [Solution] The vehicle control device 30 determines whether the clutch 19 is in a engaged or disengaged state based on the battery 9's charging request. If the vehicle control device 30 determines that the clutch 19 is in a disengaged state, it switches the clutch 19 to a engaged state, increases the output of the engine 5 to secure the driving force to move the hybrid vehicle 1, and increases the power supply to the battery 9 by decreasing the output of the front motor 11 and the rear motor 21 without changing the output of the generator 7.

Description

Technical Field

[0001] The present invention relates to a vehicle control method and a vehicle control device.

Background Art

[0002] Conventionally, as a driving mode of a hybrid vehicle, a series hybrid mode is known. The series hybrid mode is a mode in which an electric generator is driven by an internal combustion engine to generate electric power, and the electric power is used to drive an electric motor to run.

[0003] Patent Document 1 discloses increasing the cooling oil supplied to the generator to cool the generator in the series hybrid mode.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] However, even if the cooling oil supplied to the generator is increased, there is a limit to the cooling capacity, so the output of the generator may be restricted.

[0006] Therefore, most of the electric power generated by the generator is supplied to the electric motor to secure the driving force for running the vehicle.

[0007] Therefore, when there is a battery charging request during vehicle running, there is little electric power available for charging the battery, and it may take time to charge the battery with the electric power generated by the generator.

[0008] The present invention has been made in view of the above problems, and its object is to provide a vehicle control method and a vehicle control device that can shorten the battery charging time while ensuring the driving force to move the vehicle, even when there is a demand to charge the battery while the vehicle is running in a hybrid vehicle. [Means for solving the problem]

[0009] A vehicle control method and vehicle control device according to one aspect of the present invention determine whether the clutch is in a engaged or disengaged state based on a battery charge request. If it is determined that the clutch is in a disengaged state, the clutch is switched to a engaged state, the output of the internal combustion engine is increased to secure the driving force to move the hybrid vehicle, and the output of the electric motor is reduced without changing the output of the generator to increase the power supply to the battery. [Effects of the Invention]

[0010] According to the present invention, in a hybrid vehicle, even when there is a demand for battery charging while the vehicle is running, it is possible to shorten the battery charging time while ensuring the driving force to move the vehicle. [Brief explanation of the drawing]

[0011] [Figure 1] Figure 1 is a schematic diagram showing the internal configuration of a hybrid vehicle according to this embodiment. [Figure 2] Figure 2 is an explanatory diagram showing power transmission in series hybrid mode in a hybrid vehicle according to this embodiment. [Figure 3] Figure 3 is an explanatory diagram showing power transmission in the engine direct-drive mode in a hybrid vehicle according to this embodiment. [Figure 4] Figure 4 is a block diagram showing the functional configuration of the vehicle control device according to this embodiment. [Figure 5] Figure 5 is a time chart showing the operation of the hybrid vehicle according to this embodiment when a charge request is made. [Figure 6]Figure 6 is a flowchart showing the processing details when a charge request is received in the vehicle control device according to this embodiment. [Figure 7] Figure 7 is a time chart showing the operation of a hybrid vehicle according to a modified example of this embodiment when a charge request is made. [Figure 8] Figure 8 is a flowchart showing the processing details when a charge request is received in a vehicle control device according to a modified example of this embodiment. [Modes for carrying out the invention]

[0012] The embodiments will be described with reference to the drawings. In the drawings, the same parts are denoted by the same reference numerals and their descriptions are omitted.

[0013] [Overall configuration of hybrid vehicles] Referring to Figure 1, the internal configuration of the hybrid vehicle 1 will be described. The hybrid vehicle 1 comprises first drive wheels 2,2, second drive wheels 3,3, engine 5, generator 7, battery 9, front motor 11, gear trains 13a,13b, first differential 15, first drive shafts 17,17, clutch 19, rear motor 21, gear train 23, second differential 25, second drive shafts 27,27, vehicle control device 30, and cooler 200.

[0014] The first drive wheels 2,2 are located at the front of the hybrid vehicle 1 and are also referred to as the front wheels. The second drive wheels 3,3 are located at the rear of the hybrid vehicle 1 and are also referred to as the rear wheels. The first drive wheels 2,2 and the second drive wheels 3,3 are collectively referred to as the drive wheels.

[0015] Engine 5 has an output shaft that is permanently connected to the rotating shaft of the generator 7. In this configuration, the torque of engine 5 is transmitted to the generator 7. Engine 5 is also referred to as an internal combustion engine.

[0016] The generator 7 is electrically connected to the battery 9, the front motor 11, and the rear motor 21. The generator 7 generates electricity by the power supply from the engine 5 and supplies electric power to at least one of the battery 9, the front motor 11, and the rear motor 21. The generator 7 is also referred to as a generator.

[0017] As will be described later, the power supply from the generator 7 to the battery 9, the power supply from the generator 7 to the front motor 11, and the power supply from the generator 7 to the rear motor 21 can be executed according to the running state of the vehicle, the charging state of the battery 9, and the like.

[0018] The battery 9 is charged by the power supply from the generator 7. The battery 9 has a plurality of cells electrically connected to each other. Each cell is, for example, a lithium-ion battery or a nickel-hydrogen battery.

[0019] A battery sensor 9a is provided in the battery 9. The battery sensor 9a acquires the charge rate (SOC, State Of Charge) of the battery 9.

[0020] The front motor 11 is driven by the power supply from the generator 7. The output shaft of the front motor 11 is connected to the ring gear of the first differential 15 via a gear train 13a. With such a configuration, the torque of the front motor 11 is transmitted to the first differential 15 at a predetermined gear ratio via the gear train 13a.

[0021] The first differential 15 is connected to the first drive shafts 17, 17. The first drive shafts 17, 17 are respectively connected to the first drive wheels 2, 2. When the torque of the front motor 11 is transmitted to the first differential 15, it is distributed to the first drive shafts 17, 17 via the first differential 15 to rotate the first drive wheels 2, 2.

[0022] The clutch 19 is slidably mounted on the output shaft of the engine 5 and has a engaged state (see Figure 3) in which the output shaft of the engine 5 is connected to the gear train 13b, and a disengaged state (see Figure 2) in which the output shaft of the engine 5 is disconnected from the gear train 13b.

[0023] When the clutch 19 is engaged, the output shaft of the engine 5 is connected to the ring gear of the first differential 15 via the gear train 13b. In this configuration, the torque of the engine 5 is transmitted to the first differential 15 via the gear train 13b at a predetermined gear ratio. Once the torque of the engine 5 is transmitted to the first differential 15, it is distributed to the first drive shafts 17, 17 via the first differential 15, rotating the first drive wheels 2, 2. When the clutch 19 is engaged, the clutch 19 is moved to the engagement position on the output shaft of the engine 5. The engagement position is also referred to as the engine direct connection position.

[0024] On the other hand, when the clutch 19 is disengaged, the output shaft of the engine 5 is disconnected from the gear train 13b, and therefore the torque of the engine 5 is not transmitted to the first differential 15. When the clutch 19 is disengaged, the clutch 19 moves to the disengaged position on the output shaft of the engine 5. The disengaged position is also referred to as the engine disengaged position.

[0025] The gear trains 13a, 13b, the first differential 15, and the first drive shafts 17, 17 are also referred to as the drive system for the first drive wheels 2, 2. When the clutch 19 is engaged, the engine 5 is connected (directly coupled) to the drive system for the first drive wheels 2, 2. On the other hand, when the clutch 19 is disengaged, the engine 5 is disconnected from the drive system for the first drive wheels 2, 2.

[0026] The rear motor 21 is driven by power supplied from the generator 7. The output shaft of the rear motor 21 is connected to the ring gear of the second differential 25 via a gear train 23. With this configuration, the torque of the rear motor 21 is transmitted to the second differential 25 via the gear train 23 at a predetermined gear ratio. The front motor 11 and the rear motor 21 are also collectively referred to as electric motors.

[0027] The second differential 25 is connected to the second drive shafts 27, 27. The second drive shafts 27, 27 are connected to the second drive wheels 3, 3, respectively. When the torque from the rear motor 21 is transmitted to the second differential 25, it is distributed to the second drive shafts 27, 27 via the second differential 25, causing the second drive wheels 3, 3 to rotate.

[0028] The gear train 23, the second differential 25, and the second drive shafts 27,27 are also referred to as the drive system for the second drive wheels 3,3.

[0029] The vehicle control device 30 controls the operation of the engine 5, generator 7, front motor 11, and rear motor 21. The vehicle control device 30 controls the state of the clutch 19. The vehicle control device 30 monitors the charge state of the battery 9. The vehicle control device 30 controls the operation of the cooler 200. The vehicle control device 30 receives information such as charging requests from the driver.

[0030] The cooler 200, under the control of the vehicle control device 30, distributes the flow rate of the coolant used to cool the generator 7, the front motor 11, and the rear motor 21. In normal distribution, the cooler 200 distributes the flow rate of the coolant so that the flow rate of the coolant used to cool the generator 7 is the same as the flow rate of the coolant used to cool the front motor 11 and the rear motor 21.

[0031] [Driving modes for hybrid vehicles] Next, the driving modes of the hybrid vehicle 1 will be described with reference to Figures 2 and 3. The hybrid vehicle 1 can switch between a series hybrid mode and an engine-direct drive mode depending on the vehicle's driving conditions. In series hybrid mode, the front motor 11 and the rear motor 21 are used as the vehicle's power source. In engine-direct drive mode, the engine 5, the front motor 11, and the rear motor 21 are used as the vehicle's power source. In addition, in engine-direct drive mode, only the engine 5 may be used as the vehicle's power source.

[0032] Figure 2 shows the power transmission path in series hybrid mode with arrows. The direction of the arrows indicates the direction in which power is transmitted. In series hybrid mode, the clutch 19 is disengaged, and the output shaft of the engine 5 is disconnected from the gear train 13b. Therefore, the torque of the engine 5 is transmitted only to the generator 7, the torque of the front motor 11 is transmitted to the drivetrain of the first drive wheels 2,2, and the torque of the rear motor 21 is transmitted to the drivetrain of the second drive wheels 3,3.

[0033] Figure 3 shows the power transmission path in the direct-drive engine mode, indicated by arrows. The direction of the arrows indicates the direction in which power is transmitted. In the direct-drive engine mode, the clutch 19 is engaged, and the output shaft of the engine 5 is connected to the gear train 13b. Therefore, the torque of the engine 5 is transmitted to the drive system of the first drive wheels 2,2 and also to the generator 7. In this way, the generator 7 generates electricity using the surplus torque of the engine 5 and supplies power to at least one of the battery 9, the front motor 11, and the rear motor 21. When the front motor 11 and the rear motor 21 are supplied with power from the generator 7, the torque of the front motor 11 is transmitted to the drive system of the first drive wheels 2,2, and the torque of the rear motor 21 is transmitted to the drive system of the second drive wheels 3,3.

[0034] [Functional configuration of vehicle control system] Next, the functional configuration of the vehicle control device 30 will be described with reference to Figure 4. The vehicle control device 30 comprises a control unit 31, a storage unit 33, a communication unit 35, an input unit 37, a display unit 39, a determination unit 41, a switching unit 43, an output control unit 45, a monitoring unit 47, and a flow rate control unit 49.

[0035] The control unit 31 controls the entire process in the vehicle control device 30. Specifically, the control unit 31 controls the operation of each of the following: the storage unit 33, the communication unit 35, the input unit 37, the display unit 39, the determination unit 41, the switching unit 43, the output control unit 45, the monitoring unit 47, and the flow rate control unit 49.

[0036] The memory unit 33 stores various information necessary for the operation of the vehicle control device 30. Specifically, the memory unit 33 pre-stores the driving mode linked to the vehicle's driving state. The memory unit 33 stores the current clutch position. The memory unit 33 stores the charge level of the battery 9 and the target charge level of the battery 9. The memory unit 33 stores the target output of the engine 5, the target output of the generator 7, the target output of the front motor 11, and the target output of the rear motor 21.

[0037] The communication unit 35 transmits and receives signals to and from the engine 5, generator 7, battery 9, front motor 11, clutch 19, rear motor 21, and cooler 200. Specifically, the communication unit 35 transmits a first output control signal to the engine 5. The communication unit 35 receives a first output signal from the engine 5, which includes the output amount of the engine 5. The communication unit 35 transmits a second output control signal to the generator 7. The communication unit 35 receives a second output signal from the generator 7, which includes the output amount of the generator 7. The communication unit 35 transmits a third output control signal to the front motor 11. The communication unit 35 receives a third output signal from the front motor 11, which includes the output amount of the front motor 11. The communication unit 35 transmits a fourth output control signal to the rear motor 21. The communication unit 35 receives a fourth output signal from the rear motor 21, which includes the output amount of the rear motor 21.

[0038] The communication unit 35 transmits a switching signal to the clutch 19. The communication unit 35 receives a switching completion signal from the clutch 19. The communication unit 35 transmits a transmission start signal and a transmission stop signal to the battery sensor 9a. The communication unit 35 receives a charge status signal from the battery sensor 9a, including the charge rate of the battery 9. The communication unit 35 transmits a flow control signal to the cooler 200.

[0039] The input unit 37 receives information such as charging requests from the driver. The display unit 39 displays the charge level of the battery 9 stored in the memory unit 33.

[0040] When the input unit 37 receives a charge request, the determination unit 41 determines whether the current driving mode is series hybrid mode or engine direct drive mode. Specifically, when the input unit 37 receives a charge request, the determination unit 41 determines whether the clutch 19 is in an open state or an engaged state. Based on the first output signal, the determination unit 41 determines whether the output of the engine 5 has reached the target output. Based on the second output signal, the determination unit 41 determines whether the output of the generator 7 has reached the target output. Based on the third output signal, the determination unit 41 determines whether the output of the front motor 11 has reached the target output. Based on the fourth output signal, the determination unit 41 determines whether the output of the rear motor 21 has reached the target output. Based on the charge status signal, the determination unit 41 determines whether the charge rate of the battery 9 has reached the target charge rate.

[0041] The switching unit 43 switches the driving mode between series hybrid mode and engine direct drive mode depending on the vehicle's driving conditions. When the switching unit 43 switches the driving mode to series hybrid mode, it sends a switching signal to the clutch 19 via the communication unit 35, causing the clutch 19 to move to the release position and disconnect the output shaft of the engine 5 from the gear train 13b. As a result, the clutch 19 is in the released state. When the clutch 19 moves to the release position, the switching unit 43 receives a switching completion signal via the communication unit 35.

[0042] When the switching unit 43 switches the driving mode to the direct engine drive mode, it sends a switching signal to the clutch 19 via the communication unit 35, causing the clutch 19 to move to the engagement position and connect the output shaft of the engine 5 to the gear train 13b. As a result, the clutch 19 enters the engagement state. When the clutch 19 moves to the engagement position, the switching unit 43 receives a switching completion signal via the communication unit 35.

[0043] The switching unit 43 switches from series hybrid mode to engine direct drive mode when the input unit 37 receives a charge request and the determination unit 41 determines that the current driving mode is series hybrid mode. The switching unit 43 also switches from engine direct drive mode to series hybrid mode when the determination unit determines that the battery 9 has reached the target charge level and the switching unit 43 switched to engine direct drive mode when a charge request was made.

[0044] The output control unit 45 controls the output of the engine 5, generator 7, front motor 11, and rear motor 21. In this embodiment, an increase or decrease in output refers to an increase or decrease in the absolute value of the output.

[0045] When the output control unit 45 increases or decreases the output of the engine 5, it transmits a first output control signal via the communication unit 35, which includes an output increase instruction or an output decrease instruction. Based on the output increase instruction or output decrease instruction included in the first output control signal, the engine 5 controls the amount of torque it generates to increase or decrease the output of the engine 5 by a predetermined amount.

[0046] When the output control unit 45 increases or decreases the output of the generator 7, it transmits a second output control signal via the communication unit 35, which includes an output increase instruction or an output decrease instruction. Based on the output increase instruction or output decrease instruction included in the second output control signal, the generator 7 controls the amount of torque it generates to increase or decrease the output of the generator 7 by a predetermined amount.

[0047] When the output control unit 45 increases or decreases the output of the front motor 11, it transmits a third output control signal via the communication unit 35, which includes an output increase instruction or an output decrease instruction. Based on the output increase instruction or output decrease instruction included in the third output control signal, the front motor 11 controls the amount of torque it generates, thereby increasing or decreasing the output of the front motor 11 by a predetermined amount.

[0048] When the output control unit 45 increases or decreases the output of the rear motor 21, it transmits a fourth output control signal via the communication unit 35, which includes an output increase instruction or an output decrease instruction. Based on the output increase instruction or output decrease instruction included in the fourth output control signal, the rear motor 21 controls the amount of torque it generates, thereby increasing or decreasing the output of the rear motor 21 by a predetermined amount.

[0049] The monitoring unit 47 monitors the charge level of the battery 9. Specifically, when the monitoring unit 47 starts monitoring the charge level of the battery 9, it sends a transmission start signal to the battery sensor 9a via the communication unit 35. The battery sensor 9a periodically acquires the charge level of the battery 9 in response to the transmission start signal. The monitoring unit 47 periodically receives a charge status signal, including the charge level of the battery 9, from the battery sensor 9a via the communication unit 35 and stores the received charge level of the battery 9 in the storage unit 33. When the determination unit 41 determines that the charge level of the battery 9 has reached the target charge level, the monitoring unit 47 sends a transmission stop signal to the battery sensor 9a.

[0050] The flow control unit 49 controls the flow rate distribution of the cooling water in the cooler 200. When controlling the flow rate distribution of the cooling water, the flow control unit 49 transmits a flow rate control signal to the cooler 200 via the communication unit 35. In this embodiment, the flow rate distribution of the cooling water is predetermined so that the flow rate of the cooling water used to cool the generator 7 is the same as the flow rate of the cooling water used to cool the front motor 11 and the rear motor 21.

[0051] [Vehicle control system hardware configuration] Next, the hardware configuration of the vehicle control device 30 will be described. The vehicle control device 30 includes a CPU (Central Processing Unit), ROM (Read Only Memory), RAM (Random Access Memory), and storage.

[0052] The CPU executes algorithms and programs stored in ROM. The CPU processes data loaded into RAM according to these algorithms and programs, and comprehensively controls each part of the vehicle control device 30. The CPU is also referred to as a processor.

[0053] ROM stores algorithms, programs, and other data that the CPU executes. In this embodiment, ROM stores algorithms and programs for controlling the vehicle control method described later. RAM temporarily holds computation data when the CPU executes the algorithms and programs stored in ROM. ROM and RAM are also referred to as non-volatile memory and volatile memory, respectively.

[0054] The storage unit stores various types of information. The CPU controls the reading and writing of data to and from the storage unit according to algorithms and programs stored in the ROM.

[0055] The vehicle control device 30 is equipped with interfaces that connect to various ECUs and sensors installed within the vehicle.

[0056] [Vehicle control method] Next, with reference to Figures 5 and 6, a vehicle control method performed by the vehicle control device 30 will be described. Specifically, a vehicle control method performed by the vehicle control device 30 when a charge request for the battery 9 is received will be described. In this embodiment, when the vehicle control device 30 receives a charge request for the battery 9, it controls the output of the engine 5, generator 7, front motor 11, and rear motor 21 in engine direct-drive mode to cause the generator 7 to charge the battery 9.

[0057] First, with reference to Figure 5, the operation of the hybrid vehicle 1 when a charge request is made for the battery 9 will be explained. Note that, for simplification, the time chart shown in Figure 5 does not consider the output reduction due to efficiency for each of the engine 5, generator 7, front motor 11, and rear motor 21. Also, in Figure 5, the output (power generation output) of the generator 7 is shown on the negative side because it is generated by the regenerative operation of the generator 7.

[0058] In the example shown in Figure 5, it is assumed that the hybrid vehicle 1 was running in series hybrid mode before the battery 9 received a charge request. In this embodiment, it is also assumed that the output required to run the hybrid vehicle 1 is a (kW) and does not fluctuate during battery 9 charging. Furthermore, it is assumed that the upper limit output of the generator 7 is a (kW) under normal coolant distribution. For this reason, the output of the engine 5 is controlled so that the output (power generation output) of the generator 7 does not exceed a (kW).

[0059] The power required to drive the hybrid vehicle 1 is also called the driving resistance power. Furthermore, the power required to drive the hybrid vehicle 1 can also be expressed as the driving force required to drive the first drive wheels 2,2 and the second drive wheels 3,3.

[0060] As shown in Figure 5, before receiving a charge request for the battery 9 (before time t1 in Figure 5), the vehicle control device 30 controls the outputs of the engine 5, generator 7, front motor 11, and rear motor 21 so that the output of the engine 5 is a (kW), the output of the generator 7 (power generation output) is a (kW), the output of the front motor 11 is a / 2 (kW), and the output of the rear motor 21 is a / 2 (kW). Note that the output of the generator 7 is not limited to being equally distributed to the front motor 11 and the rear motor 21, and does not have to be equally distributed.

[0061] Thus, the output a (kW) of engine 5 is used to generate electricity for generator 7, and the output a (kW) of generator 7 is distributed to the front motor 11 and the rear motor 21. The output a / 2 (kW) of front motor 11 is used to drive the first drive wheels 2,2, and the output a / 2 (kW) of rear motor 21 is used to drive the second drive wheels 3,3.

[0062] When the vehicle control device 30 receives a charge request for the battery 9 (time t1 in Figure 5), it switches the driving mode from series hybrid mode to engine direct drive mode. Specifically, the vehicle control device 30 moves the clutch 19 from the released position to the engaged position, switching the state of the clutch 19 from the released state to the engaged state (see times t1 to t2 in Figure 5). The vehicle control device 30 does not change the output of the engine 5, generator 7, front motor 11, and rear motor 21 when switching the clutch 19.

[0063] When the clutch 19 moves to the engagement position and switches to the engaged state (time t2 in Figure 5), the vehicle control device 30 controls the outputs of the engine 5, generator 7, front motor 11, and rear motor 21 so that the output of the engine 5 is (a × 2 - c × 2) (kW), the output of the generator 7 (power generation output) is a (kW), the output of the front motor 11 is c (kW), and the output of the rear motor 21 is c (kW) (see time t2 to t3 in Figure 5). After a certain period of time has elapsed, the output of the engine 5 becomes (a × 2 - c × 2) (kW), the output of the generator 7 (power generation output) becomes a (kW), the output of the front motor 11 becomes c (kW), and the output of the rear motor 21 becomes c (kW) (time t3 in Figure 5).

[0064] Thus, in order to maintain the output of the generator 7 at a (kW), from time t3 onward, of the engine 5's output (a × 2 - c × 2) (kW), a (kW) is used for generating electricity with the generator 7, and (ac × 2) (kW) is used as the driving force for the first drive wheels 2,2. In addition, of the generator 7's output a (kW), c × 2 (kW) is distributed to the front motor 11 and the rear motor 21, and (ac × 2) (kW) is used to charge the battery 9.

[0065] The output c (kW) of the front motor 11 is used to drive the first drive wheels 2,2, and the output c (kW) of the rear motor 21 is used to drive the second drive wheels 3,3. Therefore, the output required to drive the hybrid vehicle 1 can be maintained at a (= (ac × 2) + c + c) (kW).

[0066] With this output control, from time t3 onward, the battery 9 can be charged at a charging output of (AC x 2) (kW) while driving.

[0067] Furthermore, the vehicle control device 30 may control the outputs of the front motor 11 and the rear motor 21 so that after the clutch 19 switches to the engaged state, the outputs of the front motor 11 and the rear motor 21 become 0 (kW). In this case, the vehicle control device 30 controls the outputs of the engine 5 and the generator 7 so that the output of the engine 5 becomes a × 2 (kW) and the output of the generator 7 becomes a (kW). With this output control, from time t3 onward, the output a (kW) of the generator 7 can be used to charge the battery 9 while driving.

[0068] Next, referring to Figure 6, the processing performed by the vehicle control device 30 when a charge request for the battery 9 is received will be explained.

[0069] As shown in Figure 6, when the input unit 37 receives a charge request in step S11, the determination unit 41 determines in step S13 whether the current driving mode is series hybrid mode or engine direct drive mode. Specifically, when the input unit 37 receives a charge request, the determination unit 41 determines whether the clutch 19 is in an open state or an engaged state.

[0070] If the determination unit 41 determines that the current driving mode is series hybrid mode, that is, if it determines that the clutch 19 is in the disengaged state, in step S15, the switching unit 43 transmits a switching signal to the clutch 19 via the communication unit 35. As a result, the switching unit 43 moves the clutch 19 from the disengaged position to the engaged position, switching the clutch 19 from the disengaged state to the engaged state, and switching the driving mode to engine direct drive mode. When the switching unit 43 receives a switching completion signal from the clutch 19 via the communication unit 35, the control unit 31 proceeds to the processing in steps S17 and S19. On the other hand, if the determination unit 41 determines that the current driving mode is engine direct drive mode, that is, if it determines that the clutch 19 is in the engaged state, the control unit 31 proceeds to the processing in steps S17 and S19.

[0071] In step S17, the output control unit 45 transmits a third output control signal and a fourth output control signal to the front motor 11 and the rear motor 21, respectively, via the communication unit 35. Each of the third output control signal and the fourth output control signal includes an output reduction instruction. As a result, each of the front motor 11 and the rear motor 21 reduces its output by a predetermined amount.

[0072] In step S19, the output control unit 45 transmits a first output control signal to the engine 5 via the communication unit 35. The first output control signal includes an output increase instruction. As a result, the engine 5 increases its output by a predetermined amount.

[0073] In this embodiment, the output control unit 45 does not change the output of the generator 7, and therefore does not transmit the second output control signal.

[0074] When the output control unit 45 transmits a first output control signal, the determination unit 41 receives a first output signal from the engine 5 via the communication unit 35. When the output control unit 45 transmits a third output control signal, the determination unit 41 receives a third output signal from the front motor 11 via the communication unit 35. When the output control unit 45 transmits a fourth output control signal, the determination unit 41 receives a fourth output signal from the rear motor 21 via the communication unit 35.

[0075] In step S21, the determination unit 41 determines whether the output of the engine 5 has reached the target output based on the first output signal, whether the output of the front motor 11 has reached the target output based on the third output signal, and whether the output of the rear motor 21 has reached the target output based on the fourth output signal. In this embodiment, the target output of the engine 5 is (a × 2 - c × 2) (kW), and the target output of the front motor 11 and the rear motor 21, respectively, is c (kW).

[0076] If the determination unit 41 determines that the output of the engine 5 has reached the target output, the output of the front motor 11 has reached the target output, and the output of the rear motor 21 has reached the target output, the control unit 31 proceeds to the process in step S23. On the other hand, if the determination unit 41 determines that the output of the engine 5 has not reached the target output, the control unit 31 returns to the process in step S19. If the determination unit 41 determines that at least one of the outputs of the front motor 11 and the rear motor 21 has not reached the target output, the control unit 31 returns to the process in step S17.

[0077] When a predetermined time has elapsed since the output control unit 45 completed output control of the engine 5, generator 7, front motor 11, and rear motor 21, the monitoring unit 47 transmits a transmission start signal to the battery sensor 9a via the communication unit 35 and receives a charging status signal from the battery sensor 9a. In step S23, the determination unit 41 determines, based on the charging status signal, whether the charge rate of the battery 9 has reached the target charge rate.

[0078] If the determination unit 41 determines that the battery 9 has reached the target charge level, the control unit 31 proceeds to steps S25 and S27. If the determination unit 41 determines that the battery 9 has not reached the target charge level, the control unit 31 returns to step S23.

[0079] In step S25, the output control unit 45 transmits a third output control signal and a fourth output control signal to the front motor 11 and the rear motor 21, respectively, via the communication unit 35. Each of the third and fourth output control signals includes an output increase instruction. As a result, each of the front motor 11 and the rear motor 21 increases its output by a predetermined amount. Similar to step S21, the output control unit 45 continues the process in step S25 until the output of each of the front motor 11 and the rear motor 21 reaches a / 2 (kW) based on the operation of the determination unit 41.

[0080] In step S27, the output control unit 45 transmits a first output control signal to the engine 5 via the communication unit 35. The first output control signal includes an output reduction instruction. As a result, the engine 5 reduces its output by a predetermined amount. Similar to step S21, the output control unit 45 continues the process in step S27 until the output of the engine 5 reaches a (kW) based on the operation of the determination unit 41.

[0081] In step S29, the switching unit 43 transmits a switching signal to the clutch 19 via the communication unit 35. This causes the switching unit 43 to move the clutch 19 from the engaged position to the released position, switching the clutch 19 from the engaged state to the released state and switching the driving mode to series hybrid mode. When the switching unit 43 receives a switching completion signal from the clutch 19 via the communication unit 35, the control unit 31 terminates the series of processes.

[0082] [Effects / Effects] According to this embodiment, the vehicle control method and vehicle control device 30 determine whether the clutch 19 is in a engaged or disengaged state based on a charge request from the battery 9. If it is determined that the clutch 19 is in a disengaged state, it switches the clutch 19 to a engaged state, increases the output of the engine 5 to secure the driving force to move the hybrid vehicle 1, and increases the power supply to the battery 9 by decreasing the output of the front motor 11 and the rear motor 21 without changing the output of the generator 7.

[0083] With the above configuration, it is possible to increase the power supply to the battery 9 while ensuring the driving force to propel the hybrid vehicle 1. Therefore, according to the vehicle control method and vehicle control device 30 of this embodiment, even when there is a charge request for the battery 9 while the hybrid vehicle 1 is running, it is possible to shorten the charging time of the battery 9 while ensuring the driving force to propel the vehicle.

[0084] According to this embodiment, the vehicle control method and vehicle control device 30 determine whether the battery 9 has reached a target charge level after a predetermined time has elapsed since completing output control of the engine 5, generator 7, front motor 11, and rear motor 21. If it determines that the battery 9 has reached a target charge level, it reduces the output of the engine 5 and increases the output of the front motor 11 and rear motor 21 without changing the output of the generator 7. Based on a charge request from the battery 9, the vehicle control method and vehicle control device 30 switches the clutch 19 to a engaged state, then switches the clutch 19 to a disengaged state.

[0085] With the configuration described above, once the battery 9 is fully charged, the vehicle returns to the previous driving mode, minimizing the impact on the vehicle's operation while charging the battery 9.

[0086] [Differentiation] As described above, embodiments of the present invention have been presented, but the statements and drawings that constitute part of this disclosure should not be understood as limiting the invention. Various alternative embodiments, examples, and operational techniques will become apparent to those skilled in the art from this disclosure.

[0087] For example, in the embodiment described above, the flow rate of the cooling water used to cool the generator 7 was predetermined to be the same as the flow rate of the cooling water used to cool the front motor 11 and the rear motor 21, but the invention is not limited to this. In this modified example, when the vehicle control device 30 receives a charge request, switches the driving mode to the direct engine drive mode to charge the battery 9, and then receives an instruction for additional charge output, the flow rate of the cooling water used to cool the generator 7 is increased to be greater than the flow rate of the cooling water used to cool the front motor 11 and the rear motor 21.

[0088] Referring to Figures 7 and 8, the vehicle control method performed by the vehicle control device 30 in this modified example will be described. First, referring to Figure 7, the operation of the hybrid vehicle 1 when a charge request for the battery 9 is made will be described. Note that the operation up to time t3 is the same as the operation up to time t3 in Figure 5 in the embodiment described above, so the explanation will be omitted.

[0089] In the embodiment described above, the upper limit output of the generator 7 was a (kW) due to the normal distribution of cooling water. In contrast, in this modified example, by increasing the flow rate of the cooling water used to cool the generator 7 to more than the flow rate of the cooling water used to cool the front motor 11 and the rear motor 21, the upper limit output of the generator 7 increases to (a + d) (kW). The value of the increase amount d is determined by the output performance of the generator 7.

[0090] As shown in Figure 7, when the vehicle control device 30 receives an instruction to add a charge output (time t4 in Figure 7), it controls the cooler 200 so that the flow rate of the coolant used to cool the generator 7 is greater than the flow rate of the coolant used to cool the front motor 11 and the rear motor 21 by a set value (see times t4-t5 in Figure 7).

[0091] The vehicle control device 30 simultaneously controls the outputs of the engine 5, generator 7, front motor 11, and rear motor 21 so that the output of the engine 5 is (a × 2 - c × 2 + d) (kW), the output of the generator 7 (power generation output) is (a + d) (kW), the output of the front motor 11 is c (kW), and the output of the rear motor 21 is c (kW) (see time t4 to time t5 in Figure 7). After a certain period of time has elapsed, the output of the engine 5 becomes (a × 2 - c × 2 + d) (kW), the output of the generator 7 (power generation output) becomes (a + d) (kW), the output of the front motor 11 becomes c (kW), and the output of the rear motor 21 becomes c (kW) (time t5 in Figure 7).

[0092] Thus, the output of the generator 7 increases to (a+d)(kW), so from time t5 onward, of the engine 5's output (a×2-c×2+d)(kW), (a+d)(kW) is used for generating electricity with the generator 7, and (ac×2)(kW) is used to drive the first drive wheels 2,2. In addition, of the generator 7's output (a+d)(kW), c×2(kW) is distributed to the front motor 11 and the rear motor 21, and (ac×2+d)(kW) is used to charge the battery 9.

[0093] The output c (kW) of the front motor 11 is used to drive the first drive wheels 2,2, and the output c (kW) of the rear motor 21 is used to drive the second drive wheels 3,3. Therefore, the output required to drive the hybrid vehicle 1 can be maintained at a (= (ac × 2) + c + c) (kW).

[0094] This output control allows the charging output to be increased from (ac×2)(kW) to (ac×2+d)(kW) while driving, starting from time t5.

[0095] Next, referring to Figure 8, the processing content of the vehicle control device 30 when a charge request for the battery 9 is received will be explained. Note that the processing content of steps S51 to S63 and steps S75 to S81 are the same as the processing content of steps S11 to S23 and steps S23 to S29 in Figure 6 in the embodiment described above, respectively, so their explanation will be omitted.

[0096] As shown in Figure 8, in step S65, the determination unit 41 determines whether the input unit 37 has received an additional charge output instruction. If the determination unit 41 determines that the input unit 37 has not received an additional charge output instruction, the control unit 31 returns to the process in step S63. On the other hand, if the determination unit 41 determines that the input unit 37 has received an additional charge output instruction, the control unit 31 proceeds to the process in step S67.

[0097] In step S67, the flow control unit 49 transmits a flow control signal to the cooler 200 via the communication unit 35. As a result, the flow rate of the cooling water used to cool the generator 7 becomes greater than the flow rate of the cooling water used to cool the front motor 11 and the rear motor 21 by a set value.

[0098] In step S69, the output control unit 45 transmits a second output control signal to the generator 7 via the communication unit 35. The second output control signal includes an output increase instruction. As a result, the generator 7 increases its output by a predetermined amount.

[0099] In step S71, the output control unit 45 transmits a first output control signal to the engine 5 via the communication unit 35. The first output control signal includes an output increase instruction. As a result, the engine 5 increases its output by a predetermined amount.

[0100] In this modified example, the output control unit 45 does not change the outputs of the front motor 11 and the rear motor 21, therefore, the third output control signal and the fourth output control signal are not transmitted.

[0101] When the output control unit 45 transmits the first output control signal, the determination unit 41 receives the first output signal from the engine 5 via the communication unit 35. When the output control unit 45 transmits the second output control signal, the determination unit 41 receives the second output signal from the generator 7 via the communication unit 35.

[0102] In step S73, the determination unit 41 determines, based on the first output signal, whether the output of the engine 5 has reached the target output, and based on the second output signal, whether the output of the generator 7 has reached the target output. In this modified example, the target output of the engine 5 is (a × 2 - c × 2 + d) (kW), and the target output of the generator 7 is (a + d) (kW).

[0103] If the determination unit 41 determines that the output of the engine 5 has reached the target output and the output of the generator 7 has reached the target output, the control unit 31 proceeds to step S75. On the other hand, if the determination unit 41 determines that the output of the engine 5 has not reached the target output, the control unit 31 returns to step S71. If the determination unit 41 determines that the output of the generator 7 has not reached the target output, the control unit 31 returns to step S69.

[0104] According to this modified example, the vehicle control method and vehicle control device 30 determine whether the battery 9 has reached a target charge level after a predetermined time has elapsed since completing output control of the engine 5, generator 7, front motor 11, and rear motor 21. If the vehicle control method and vehicle control device 30 determines that the battery 9 has not reached a target charge level, based on an additional charge output instruction, it controls the flow rate distribution of the coolant used to cool the generator 7, front motor 11, and rear motor 21, increasing the flow rate of the coolant to cool the generator 7 and decreasing the flow rate of the coolant to cool the front motor 11 and rear motor 21. The vehicle control method and vehicle control device 30 also increases the output of the engine 5 and the generator 7.

[0105] As a result of the above configuration, the specific heat of water is relatively high, which allows for an efficient increase in the upper limit output of the generator 7. Therefore, the output (charging output) of the generator 7 can be increased, and the charging time of the battery 9 can be further shortened.

[0106] [Other variations] In the embodiment described above, in the example shown in Figure 5, it was assumed that the hybrid vehicle 1 was running in series hybrid mode before receiving a charge request for the battery 9. However, the embodiment is not limited to this, and the hybrid vehicle 1 may also be running in engine direct drive mode.

[0107] In this case, before receiving a charge request for battery 9, the vehicle control device 30 controls the outputs of engine 5, generator 7, front motor 11, and rear motor 21 so that the output of engine 5 is (a - c × 2 + e) ​​(kW), the output of generator 7 (power generation output) is c × 2 (kW), the output of front motor 11 is c (kW), and the output of rear motor 21 is c (kW).

[0108] The output of the front motor 11 and the rear motor 21 may be 0 (kW). In this case, the vehicle control device 30 controls the outputs of the engine 5 and the generator 7 so that the output of the engine 5 is (a + e) ​​(kW) and the output of the generator 7 (power generation output) is 0 (kW).

[0109] Thus, since the output required to drive the hybrid vehicle 1 is a (kW), the engine 5 outputs an additional e (kW). In this state, when the input unit 37 receives a charge request, the output control unit 45 transmits a second output control signal to the generator 7 via the communication unit 35. The second output control signal includes an output increase instruction that increases the output by e (kW). As a result, the generator 7 can utilize the surplus output from the engine 5 as a charge output.

[0110] With the above configuration, when the hybrid vehicle 1 is running in engine-direct drive mode and receives a request to charge the battery 9, the vehicle control method and vehicle control device 30 can increase the output of the generator 7 according to the output of the engine 5. Therefore, even when the hybrid vehicle 1 receives a request to charge the battery 9 while the vehicle is running, it is possible to shorten the charging time of the battery 9 while ensuring the driving force to move the vehicle.

[0111] In the embodiments described above, the hybrid vehicle 1 was a four-wheel drive vehicle in which the power of the engine 5 is transmitted to the first drive wheels 2,2 and the second drive wheels 3,3, but it is not limited to this. The hybrid vehicle 1 may also be a two-wheel drive vehicle in which the power of the engine 5 and the motor is transmitted to either the first drive wheels 2,2 or the second drive wheels 3,3.

[0112] For example, if the hybrid vehicle 1 is a two-wheel drive vehicle in which the power of the engine 5 and the motor is transmitted only to the first drive wheels 2,2, then the rear motor 21, gear train 23, and second differential 25 are omitted. In this case, as shown in the example in Figure 5, the output of the front motor is c × 2 (kW).

[0113] With the above configuration, regardless of whether the hybrid vehicle 1 is a four-wheel drive or two-wheel drive vehicle, if there is a charge request for the battery 9 while the vehicle is running, it is possible to shorten the charging time of the battery 9 while ensuring the driving force to move the vehicle.

[0114] In the above-described embodiment, the engine 5 and generator 7 are located on the side of the first drive wheels 2,2 (front wheels) in the hybrid vehicle 1, but the vehicle is not limited to this. The engine 5 and generator 7 may also be located on the side of the second drive wheels 3,3 (rear wheels) in the hybrid vehicle 1.

[0115] The embodiments, modifications, and other modifications described above may be combined as appropriate. [Explanation of symbols]

[0116] 1. Hybrid vehicle 2. First drive wheel 3. Second drive wheel 5 Engine 7 Generators 9 batteries 11 Front motor 19 Clutch 21 Rear Motor 30 Vehicle control device 41 Judgment section 43 Switching section 45 Output control unit

Claims

1. Internal combustion engines and A generator that is permanently connected to the internal combustion engine and generates electricity through the operation of the internal combustion engine, A battery that is charged by power supplied from the aforementioned generator, An electric motor connected to the drive system of the drive wheels and driven by power supplied from the generator, A clutch having a fastening state that connects the internal combustion engine to the drive system of the drive wheel, and a release state that disconnects the internal combustion engine from the drive system of the drive wheel, A vehicle control method performed by a vehicle control device that controls a hybrid vehicle that is driven by the driving force from at least one of the internal combustion engine and the electric motor, comprising: A first determination step is to determine whether the clutch is in the engaged state or the disengaged state based on the battery charging request, If the first determination step determines that the clutch is in the disengaged state, the first switching step involves switching the clutch to the engaged state, In the aforementioned fastening state, a first output control step increases the output of the internal combustion engine to secure the driving force to move the hybrid vehicle, and without changing the output of the generator, decreases the output of the electric motor to increase the power supply to the battery. A vehicle control method comprising:

2. A second determination step, which determines whether the battery's charge level has reached a target charge level after a predetermined time has elapsed since the completion of the first output control step, If the second determination step determines that the battery charge level has not reached the target charge level, the flow rate control step controls the flow rate distribution of the cooling water used to cool the generator and the motor, based on an additional instruction for charging output, to increase the flow rate of the cooling water used to cool the generator and decrease the flow rate of the cooling water used to cool the motor. A second output control step of increasing the output of the internal combustion engine and the output of the generator, The vehicle control method according to claim 1, further comprising the following:

3. The vehicle control method according to claim 1, further comprising a third output control step of increasing the output of the generator in accordance with the output of the internal combustion engine if the first determination step determines that the clutch is in the engaged state.

4. The vehicle control method according to claim 1, wherein the drive wheels include at least one of the front wheels and rear wheels of the hybrid vehicle.

5. In the second determination step, if it is determined that the battery's charge level has reached the target charge level, a fourth output control step is performed in which the output of the internal combustion engine is reduced and the output of the electric motor is increased without changing the output of the generator. If the clutch is switched to the engaged state in the first switching step, a second switching step is performed to switch the clutch back to the disengaged state, The vehicle control method according to claim 2, further comprising the following:

6. Internal combustion engines and A generator that is permanently connected to the internal combustion engine and generates electricity through the operation of the internal combustion engine, A battery that is charged by power supplied from the aforementioned generator, An electric motor connected to the drive system of the drive wheels and driven by power supplied from the generator, A clutch having a fastening state that connects the internal combustion engine to the drive system of the drive wheel, and a release state that disconnects the internal combustion engine from the drive system of the drive wheel, A vehicle control device for controlling a hybrid vehicle that is driven by the driving force from at least one of the internal combustion engine and the electric motor, comprising: A determination unit that determines whether the clutch is in the engaged state or the disengaged state based on the battery charging request, If the determination unit determines that the clutch is in the disengaged state, the switching unit switches the clutch to the engaged state, In the aforementioned fastening state, an output control unit increases the output of the internal combustion engine to secure the driving force to propel the hybrid vehicle, and without changing the output of the generator, decreases the output of the electric motor to increase the power supply to the battery, A vehicle control device equipped with the following features.

Images