JP7709098B2 - Hybrid Vehicles - Google Patents

Description

This case relates to a hybrid vehicle that implements regenerative motoring control.

Conventionally, hybrid vehicles are known that are able to obtain regenerative braking force by charging a battery with regenerative power generated by a driving motor. In this type of hybrid vehicle, there is a risk that regenerative braking force will not be obtained if the charging of the battery is limited (for example, if the battery is nearly fully charged or if the battery breaks down). Therefore, a control (regenerative motoring control) has been proposed that balances the power balance by having a motor other than the driving motor consume regenerative power and idle the engine. This type of control makes it possible to ensure regenerative braking force while limiting the charging of the battery (for example, see Patent Document 1).

JP 2020-049974 A

In the above-mentioned regenerative motoring control, the rotation speed when the engine is idling is set according to the magnitude of the regenerative power. On the other hand, if the accelerator pedal is depressed during regenerative motoring control to end regenerative power generation and the engine start conditions are met, the engine is controlled to rotate independently at a rotation speed according to the accelerator opening. This causes the engine rotation speed to fluctuate suddenly, which can cause the driver to feel uncomfortable.

For example, when the engine speed during regenerative motoring control is relatively high, if the accelerator pedal is lightly depressed, the engine speed drops suddenly and the engine noise and vibration become extremely quiet. When this happens, the driver feels as if the engine has become quieter, even though he or she is trying to accelerate the vehicle. This makes it seem as if the driver's operation of the vehicle is not in harmony with the actual behavior of the vehicle, and the driver does not get a good driving feeling.

One of the objectives of this invention was devised in light of the above-mentioned problems, and is to provide a hybrid vehicle that improves the driving feeling. However, this objective is not the only objective. Another objective of this invention is to achieve effects that cannot be obtained with conventional technology, which are derived from the configurations shown in the "Description of Embodiments" described below.

The disclosed hybrid vehicle can be realized as the following disclosed aspects or application examples, and solves at least some of the above problems.
The disclosed hybrid vehicle includes an engine, a motor that drives wheels and performs regenerative braking, a generator that generates electricity using the driving force of the engine and drives the engine, and a battery connected to the motor and the generator. The vehicle also includes a control device that performs regenerative motoring control to supply regenerative power from the motor to the generator and motor the engine at a predetermined target rotation speed when the accelerator is released during traveling. When the accelerator is released during the regenerative motoring control, the control device stops the regenerative motoring control and transitions the operating state of the engine from a motoring state to a firing state, and performs a first power generation control to cause the generator to generate electricity while firing the engine with the engine rotation speed fixed at the target rotation speed at the time the accelerator was released.

According to the disclosed hybrid vehicle, when the accelerator is turned on while regenerative motoring control is being performed, regenerative motoring control is stopped and first power generation control is performed. The first power generation control is a control that causes the generator to generate power while firing the engine with the engine speed fixed at the target rotation speed at that time. By performing such first power generation control, it is possible to suppress fluctuations in engine speed during the transition from regenerative motoring control to first power generation control, and it is possible to perform power generation by the generator without changing engine noise or vibration. Therefore, it is possible to improve the driving feeling when accelerating from regenerative motoring control.

FIG. 1 is a block diagram showing a configuration of a hybrid vehicle. 4 is a graph illustrating an example of the relationship between an accelerator opening degree and a driver required output. 4 is a graph illustrating an example of the relationship between vehicle speed and a target rotation speed of an engine. 4 is a flowchart illustrating a flow of a first power generation control and a second power generation control. 5 is a time chart illustrating the operation of the first power generation control and the second power generation control. 3 is a graph illustrating an example of an output characteristic of an engine.

The disclosed hybrid vehicle can be implemented according to the following examples.

[1. Device configuration]
1 is a block diagram illustrating the configuration of a hybrid vehicle 1 according to an embodiment. The hybrid vehicle 1 (also simply referred to as vehicle 1) is a hybrid vehicle (HEV, Hybrid Electric Vehicle) or a plug-in hybrid vehicle (PHEV, Plug-in Hybrid Electric Vehicle) equipped with an engine 2 and a motor 3 as drive sources, a generator 4 as a power generation device, and a battery 5 as a power storage device. A plug-in hybrid vehicle means a hybrid vehicle capable of externally charging the battery 5 or externally supplying power from the battery 5. A plug-in hybrid vehicle is provided with a charging port (inlet) for inserting a charging cable through which power is supplied from an external charging facility, and a receptacle (outlet) for external power supply.

The engine 2 is an internal combustion engine such as a gasoline engine or a diesel engine. A generator 4 is connected to the drive shaft of the engine 2. The generator 4 is a generator (electric motor/generator) that combines the function of driving the engine 2 with the power of the battery 5 and the function of generating electricity using the driving force of the engine 2. The generated electricity of the generator 4 is used to drive the motor 3 and charge the battery 5. A speed change mechanism (not shown) may be installed on the power transmission path connecting the engine 2 and the generator 4.

The motor 3 is an electric motor (electric motor/generator) that has both the function of propelling the vehicle 1 using the power of the battery 5 and the power generated by the generator 4, and the function of charging the battery 5 with power generated by regeneration. The battery 5 is a secondary battery such as a lithium-ion secondary battery or a nickel-metal hydride battery. The drive shaft of the motor 3 is connected to the drive wheels of the vehicle 1. A speed change mechanism (not shown) may be installed on the power transmission path connecting the motor 3 and the drive wheels.

A clutch 6 is interposed on the power transmission path connecting the engine 2 and the motor 3. The engine 2 is connected to the drive wheels via the clutch 6, and the motor 3 is disposed closer to the drive wheels than the clutch 6. The generator 4 is connected to the engine 2 side than the clutch 6. When the clutch 6 is disconnected (released), the engine 2 and the generator 4 are disconnected from the drive wheels, and the motor 3 is connected to the drive wheels. Therefore, for example, by operating only the motor 3, "EV driving (motor-only driving)" is realized. In addition, by operating the engine 2 and causing the generator 4 to generate electricity, "series driving" is realized. Series driving means that the vehicle runs on the driving force of the motor 3 while the generator 4 generates electricity with the driving force of the engine 2.

On the other hand, when the clutch 6 is connected (fastened), the engine 2, motor 3, and generator 4 are all connected to the drive wheels. Therefore, for example, by operating only the engine 2, "engine running (running only with the engine)" is achieved. In addition, by driving the motor 3 and the generator 4, "parallel running" is achieved. The above series running and parallel running are both referred to as "hybrid running".

The operating states of the engine 2, motor 3, generator 4, battery 5, and clutch 6 are controlled by a control device 10. The control device 10 is a computer (electronic control device, ECU, Electronic Control Unit) that has the function of controlling the operating states of at least the engine 2 and the generator 4. The control device 10 has a built-in processor (arithmetic processing device) and memory (storage device). The contents of the control performed by the control device 10 (control program) are stored in the memory, and are executed by appropriately loading the contents into the processor.

In this embodiment, an accelerator opening sensor 7, a brake opening sensor 8, and a vehicle speed sensor 9 are connected to the control device 10. The accelerator opening sensor 7 is a sensor that detects parameters corresponding to the amount of depression of the accelerator pedal (accelerator opening, accelerator pedal stroke, throttle opening, etc.). The brake opening sensor 8 is a sensor that detects parameters corresponding to the amount of depression of the brake pedal (brake opening, brake pedal stroke, brake fluid pressure, etc.). The vehicle speed sensor 9 is a sensor that detects the traveling speed (vehicle speed) of the vehicle 1. Information detected by each of these sensors 7 to 9 is transmitted to the control device 10.

Figure 2 is a graph illustrating the characteristics that define the relationship between the accelerator opening [%] detected by the accelerator opening sensor 7 and the driver required output [kW] set by the control device 10. The accelerator opening is the amount of depression of the accelerator pedal (e.g., the accelerator pedal stroke or the rotation angle of the accelerator pedal relative to the fulcrum) expressed as a percentage. The driver required output is a parameter that corresponds to the magnitude of the output (in other words, horsepower, power, or power) that the driver is requesting to run the vehicle 1. The driver required output is generally set to a larger value as the accelerator opening is larger. The output of the drive source of the vehicle 1 is controlled so that, for example, the output becomes larger as the driver required output or vehicle speed becomes larger.

Figure 3 is a graph illustrating the relationship between the vehicle speed [km/h] detected by the vehicle speed sensor 9 and the target rotation speed [rpm] of the engine 2. The solid line graph in Figure 3 shows the characteristics of the engine 2 when motoring (when the vehicle 1 is decelerating), and the dashed line graph in Figure 3 shows the characteristics of the engine 2 when firing (when the vehicle 1 is accelerating). Motoring means that the engine 2 is idling using the generator 4 (the engine 2 is rotated and driven without burning the fuel mixture in the cylinders), and firing means that the engine 2 is rotated independently by supplying fuel and intake air to the engine 2 (the fuel mixture is burned in the cylinders). Firing can be performed at least in a driving mode in which the engine 2 is operating, and can be performed during series driving, for example.

The target rotation speed of engine 2 during motoring is set to increase as the vehicle speed increases, as shown by the solid line graph in Figure 3. However, in a high-speed region where the vehicle speed is equal to or higher than a predetermined vehicle speed, the target rotation speed of engine 2 is fixed to a predetermined upper limit rotation speed. Also, the target rotation speed of engine 2 during firing is set to a value smaller than the target rotation speed set during motoring for the same vehicle speed, as shown by the dashed line graph in Figure 3.

If the target rotation speed setting as shown in Figure 3 is strictly adhered to, the target rotation speed will inevitably drop when the state of engine 2 transitions from a motoring state to a firing state, which may result in a worsening driving feeling. For example, when the accelerator pedal is depressed during regenerative motoring control and engine 2 enters a firing state, the rotation speed of engine 2 (engine rotation speed) drops suddenly, causing the driver to feel uncomfortable. In light of this issue, the control device 10 of this embodiment sets a target rotation speed different from the characteristics of the dashed line graph in Figure 3 when the accelerator is turned on (accelerator opening exceeds a predetermined opening) during regenerative motoring control.

2. Control Configuration
The control device 10 performs at least a regenerative motoring control and a first power generation control, and preferably performs a second power generation control in addition to these controls.
Regenerative motoring control is a control in which, while the vehicle is traveling and the accelerator is off (the accelerator opening is equal to or less than a predetermined opening, and the driver requested torque and the driver requested output are equal to or less than a threshold), regenerative power from the motor 3 is supplied to the generator 4, and the engine 2 is motored (idled) at a predetermined target rotation speed. The conditions for implementing regenerative motoring control include at least that the vehicle 1 is traveling and the accelerator is off. In addition, the conditions for implementing regenerative motoring control may include conditions such as the charging rate of the battery 5, the presence or absence of a battery failure, the battery temperature, the brake opening, the braking force required for the vehicle 1, the operating state of a friction brake device (not shown), and road surface conditions.

The first power generation control is a control that is implemented instead of the regenerative motoring control when the accelerator is turned on while the regenerative motoring control is being implemented, and it is a control that causes the generator 4 to generate power while firing the engine 2, with the rotation speed of the engine 2 fixed at the target rotation speed at that time (when the accelerator is turned on). In other words, the first power generation control is a control that suspends the setting of the target rotation speed based on the dashed line graph in Figure 3 and maintains the target rotation speed at that time when the accelerator is turned on while the regenerative motoring control is being implemented. This suppresses sudden changes in noise and vibration of the engine 2 before and after the accelerator is turned on, improving the driving feeling.

In the first power generation control, the torque of the engine 2 can be set to be greater as the accelerator opening (or the corresponding driver required output) increases. Meanwhile, since the target rotation speed is fixed, the actual rotation speed of the engine 2 is maintained. The rotation speed of the engine 2 can be changed by adjusting the load of the generator 4 on the engine 2 (the power that the generator 4 converts into electricity). In this way, in the first power generation control, the control device 10 can function to increase the torque of the engine 2 while maintaining the rotation speed of the engine 2 as the accelerator opening increases.

The termination conditions for the first power generation control include at least the accelerator being off (accelerator opening being equal to or less than a predetermined opening). If this condition is met, the control device 10 may terminate the first power generation control and resume regenerative motoring control. In addition, the termination conditions for the first power generation control in this embodiment include the driver request output exceeding a predetermined value. If this condition is met, the control device 10 terminates the first power generation control and implements the second power generation control.

The second power generation control is a control that stops the first power generation control and increases the rotation speed of the engine 2 when the driver's required output exceeds a predetermined value (or the accelerator opening exceeds a predetermined opening) during the first power generation control. In other words, the second power generation control is a control that resumes setting of the target rotation speed based on the dashed line graph in FIG. 3 when the driver deeply depresses the accelerator pedal. As a result, the noise and vibration of the engine 2 increase as the accelerator opening is increased, achieving a natural and intuitive driving feeling. The termination condition for the second power generation control includes at least the accelerator being off. When this condition is met, the control device 10 can terminate the second power generation control and resume the regenerative motoring control.

3. Flowchart
4 is a flowchart illustrating the flow of the first power generation control and the second power generation control. The control shown in this flowchart is repeatedly executed in the control device 10 at a predetermined cycle, for example, when the power switch of the vehicle 1 (not shown) is on and the vehicle 1 is ready to run (READY state). Steps A1 to A3 mainly correspond to the regenerative motoring control, steps A4 to A8 mainly correspond to the first power generation control, and step A9 corresponds to the second power generation control.

In step A1, it is determined whether or not the conditions for implementing the regenerative motoring control are satisfied. If the conditions are satisfied, the control proceeds to step A2. On the other hand, if the conditions in step A1 are not satisfied, the control in this cycle is terminated.
In step A2, the target rotation speed of the engine 2 is set according to the vehicle speed, for example, based on the characteristics shown in the solid line graph in Fig. 3. Here, the faster the vehicle speed, the higher the target rotation speed of the engine 2 is set. In other words, since the faster the vehicle speed, the greater the regenerative power generated by the motor 3, the higher the target rotation speed of the engine 2 driven by the generator 4 is set to in order to have the generator 4 consume power of an amount commensurate with the regenerative power.

In step A3, regenerative motoring control is performed based on the target rotation speed set in step A2. That is, the regenerative power of the motor 3 is supplied to the generator 4, and the generator 4 motors (runs idling) the rotation speed of the engine 2 to the target rotation speed.
In step A4, it is determined whether the accelerator is on. If it is determined that the accelerator is not on, the control for this cycle is terminated. From the next cycle onwards, the regenerative motoring control is continued as long as the conditions for implementing the regenerative motoring control are satisfied. On the other hand, if it is determined that the accelerator is on in step A4, the control proceeds to step A5.

In step A5, the driver's required output is calculated based on the accelerator opening, for example, based on the characteristics shown in Figure 2. The greater the accelerator opening, the greater the driver's required output is set to. In the following step A6, it is determined whether the driver's required output calculated in step A5 is equal to or less than a predetermined value. If this condition is met, control proceeds to step A7.

In step A7, a first power generation control is implemented in which the generator 4 generates power while firing the engine 2, with the rotation speed of the engine 2 fixed at the target rotation speed at that time. This transitions the operating state of the engine 2 from a motoring state to a firing state. The torque of the engine 2 is set according to the driver's required output. Meanwhile, the target rotation speed of the engine 2 in the firing state is maintained at the same speed as the target rotation speed of the engine 2 in the motoring state. Therefore, there is almost no change in the noise and vibration of the engine 2, and the driving feeling is improved.

In the following step A8, it is determined whether the accelerator is off. If it is determined that the accelerator is not off, control returns to step A5, and the driver request output is calculated again. Thereafter, the first power generation control continues as long as the driver request output is equal to or less than a predetermined value. Also, if it is determined in step A8 that the accelerator is off, the control for this cycle ends. From the next cycle onwards, regenerative motoring control is resumed as long as the conditions for implementing regenerative motoring control are met.

If it is determined in step A6 that the driver requested output exceeds a predetermined value, control proceeds to step A9. In step A9, second power generation control is implemented instead of first power generation control, and the rotation speed of engine 2 is changed to a rotation speed higher than the target rotation speed at that time. The torque of engine 2 is set according to the driver requested output. During second power generation control, the output of engine 2 is larger than during first power generation control, and the generated power of generator 4 also increases.

In the following step A8, it is determined whether the accelerator is off. If it is determined that the accelerator is not off, control returns to step A5, and the driver request output is calculated again. Thereafter, the second power generation control continues as long as the driver request output exceeds a predetermined value. Also, if it is determined in step A8 that the accelerator is off, the control for this cycle ends. From the next cycle onwards, regenerative motoring control is resumed as long as the conditions for implementing regenerative motoring control are met.

[4. Effect】
FIG. 5 is a time chart illustrating the actions of the first power generation control and the second power generation control. Here, it is assumed that the regenerative motoring control is performed before time _t1 and the accelerator is off. When the accelerator pedal is slightly depressed at time _t1 to turn the accelerator on, the regenerative motoring control is stopped and the first power generation control is started. The state of the engine 2 transitions from the motoring state to the firing state at time _t1 . Meanwhile, in the first power generation control, the target rotation speed of the engine 2 is maintained at the target rotation speed before time _t1 , and the actual rotation speed of the engine 2 is also constant. Therefore, there is almost no change in the noise and vibration of the engine 2, and the driving feeling is improved.

If the first power generation control is not performed, the target rotation speed of the engine 2 may be set relatively low at time _t1 , causing the actual rotation speed of the engine 2 to drop as shown by the dashed line in Fig. 5. However, in this embodiment, the first power generation control is performed, so the rotation speed of the engine 2 remains constant with almost no change before and after time _t1 . Furthermore, if the first power generation control is not performed, the torque of the engine 2 may become a slightly large value as shown by the two-dot chain line in Fig. 5.

On the other hand, in this embodiment, the rotation speed of the engine 2 is higher than when the first power generation control is not implemented, so the torque value for the same output (power) is smaller. Therefore, by reducing the torque by the amount by which the rotation speed of the engine 2 has increased compared to when the first power generation control is not implemented (in other words, so that the product of the rotation speed and the torque is constant), it is possible to maintain the rotation speed of the engine 2 without changing the power generated by the generator 4. In addition, the output of the battery 5 (power taken from the battery 5) is equal to the power consumed by the motor 3 and various auxiliary devices minus the power generated by the generator 4.

When the accelerator pedal is released at time _t2 , the first power generation control is stopped and the regenerative motoring control is resumed. The state of the engine 2 transitions from the firing state to the motoring state at time _t2 . Meanwhile, even after time _t2 , the target rotation speed of the engine 2 is kept constant, and the actual rotation speed also remains constant. Therefore, there is almost no change in the noise and vibration of the engine 2, and the driving feeling is improved.

When the accelerator pedal is depressed again at time _t3 to turn the accelerator on, the regenerative motoring control is stopped and the first power generation control is resumed. The state of the engine 2 transitions from the motoring state to the firing state at time _t3 . Meanwhile, even after time _t3 , the target rotation speed of the engine 2 is kept constant, and the actual rotation speed also remains constant. Therefore, there is almost no change in the noise and vibration of the engine 2, and the driving feeling is improved.

When the accelerator pedal is depressed further at time _t4 , the torque of the engine 2 is set to be larger as the accelerator opening becomes larger. On the other hand, since the target rotation speed of the engine 2 is kept constant even after time _t4 , the output of the engine 2 (the product of the rotation speed and the torque) increases with the increase in torque, and the generated power of the generator 4 also gradually increases. After that, when the driver's required output exceeds a predetermined value at time _t5 , the second power generation control is performed instead of the first power generation control. In the second power generation control, the setting of the target rotation speed based on the dashed line graph in FIG. 3 is resumed. As a result, the rotation speed of the engine 2 increases, and the torque of the engine 2 and the generated power of the generator 4 also increase further. Therefore, as the accelerator opening increases, the noise and vibration of the engine 2 become larger, and a natural and intuitive driving feeling is realized.

6 is a graph illustrating the output characteristics (relationship between rotation speed and torque) of the engine 2. The thick solid line in FIG. 6 indicates the relationship between the rotation speed and maximum torque of the engine 2. The thin solid lines in FIG. 6 are curves connecting operating points at which the same thermal efficiency (fuel consumption) is obtained at a certain thermal efficiency interval, and are contour lines for high and low thermal efficiency. An operating point _P0 in FIG. 6 is an operating point of the engine 2 when the first power generation control is not performed at times _{t1 to t2} and times _t3 to _t4 in FIG. 5, and an operating point _P1 is an operating point of the engine 2 when the first power generation control is performed at times _t1 to _t2 and times t3 to _t4 in FIG. 5.

The operating point _P1 is set so that the output (the product of the rotation speed and the torque) at the operating point _P1 is the same as the output at the operating point _P0 . Therefore, the generated power of the generator 4 does not need to be changed depending on whether the first power generation control is performed or not. In addition, the thermal efficiency of the operating point _P1 is slightly lower than that of the operating point _P0 . This shows that performing the first power generation control is slightly more disadvantageous in terms of fuel consumption than not performing the first power generation control.

In addition, the operating point _P2 in Fig. 6 is the operating point of the engine 2 when the torque is increased while the rotation speed of the engine 2 is fixed from time _t4 to _t5 in Fig. 5, and the operating point _P3 is the operating point of the engine 2 in the second power generation control after time _t5 in Fig. 5, for example, an operating point located near the maximum torque of the engine 2. The operating point _P2 has a slightly higher thermal efficiency than the operating point _P1 . From this, it can be seen that in the first power generation control, the disadvantage in terms of fuel efficiency decreases as the accelerator opening is increased. In addition, since the operating point _P3 is located to the upper right of the operating point _P2 in Fig. 6, it can be seen that the output (the product of the rotation speed and the torque) is increased.

5. Effects
(1) The hybrid vehicle 1 of this embodiment includes an engine 2, a motor 3 that drives the wheels and performs regenerative braking, a generator 4 that generates electricity using the driving force of the engine 2 and drives the engine 2, and a battery 5 connected to the motor 3 and the generator 4. The hybrid vehicle 1 also includes a control device 10 that performs regenerative motoring control to supply regenerative power from the motor 3 to the generator 4 and motor the engine 2 at a predetermined target rotation speed when the vehicle is traveling and the accelerator is off. When the accelerator is turned on during the regenerative motoring control, the control device 10 stops the regenerative motoring control and performs first power generation control. The first power generation control is a control that causes the generator 4 to generate electricity while firing the engine 2 with the rotation speed of the engine 2 fixed at the target rotation speed at that time.

By implementing such control, fluctuations in the rotation speed of engine 2 can be suppressed during the transition from regenerative motoring control to first power generation control. In other words, when transitioning from the motoring state to the firing state, the target rotation speed of engine 2 in the firing state can be made the same as the target rotation speed of engine 2 in the motoring state, suppressing changes in noise and vibration of engine 2. This improves the driving feeling when accelerating from regenerative motoring control.

The initial value of the torque of the engine 2 in the first power generation control (torque _T1 at operating point _P1 in FIG. 6) is set so that the output at operating point _P1 is the same as the output at operating point _P0 . With such a setting, the output of the engine 2 can be made the same as in the existing control, and the generated power of the generator 4 can also be made the same.

(2) During the first power generation control, the control device 10 can implement control to maintain the rotational speed of the engine 2 while increasing the torque of the engine 2 as the accelerator opening becomes larger. For example, the driver's required output is set based on the characteristics shown in FIG. 2, and the torque of the engine 2 is controlled based on this driver's required output. This control can increase the output of the engine 2 while suppressing changes in noise and vibration of the engine 2, improving the driving feeling during acceleration from the regenerative motoring control. Furthermore, by increasing the output of the engine 2, the amount of power generated by the generator 4 can be increased. Therefore, the power for driving the motor 3 can be increased, and a good acceleration feeling can be achieved.

(3) When the driver's requested output exceeds a predetermined value during the first power generation control, the control device 10 can execute a second power generation control in which the first power generation control is stopped and the rotation speed of the engine 2 is increased. For example, as after time t5 in Fig. ₅ , when the driver's requested output increases, the rotation speed of the engine 2 is increased within a range equal to or higher than the target rotation speed, thereby realizing a natural behavior of the engine 2 and improving the driving feeling. In addition, the power generated by the generator 4 can be increased to improve the acceleration performance of the vehicle 1 and improve the driving feeling.

(4) The control device 10 described above can resume regenerative motoring control when the accelerator is released while the first power generation control is being performed. This type of control makes it possible to resume regenerative motoring control without changing the noise and vibration of the engine 2 when transitioning from the firing state to the motoring state. This can therefore improve the driving feeling after the first power generation control.

[6. Other]
The above embodiment is merely illustrative, and is not intended to exclude various modifications or application of techniques not explicitly stated in the embodiment. Each configuration of the embodiment can be modified in various ways without departing from the spirit of the embodiment. Furthermore, each configuration of the embodiment can be selected as necessary, or can be combined appropriately.

For example, in the above embodiment, the control device 10 is illustrated as performing the regenerative motoring control, the first power generation control, and the second power generation control, but the second power generation control can be omitted. In addition, in the above embodiment, when the accelerator is released during the implementation of the first power generation control, the regenerative motoring control is resumed, but such control is not essential. In addition, the torque of the engine 2 in the first power generation control may be set according to the accelerator opening, may be set based on other parameters, or may be a fixed value set in advance. At least, by transitioning the regenerative motoring control to the first power generation control while fixing the rotation speed of the engine 2 to the target rotation speed at that time, the same action and effect as the above embodiment can be obtained.

This invention is applicable to the hybrid vehicle manufacturing industry and also to the hybrid vehicle control device manufacturing industry.

1. Vehicle (hybrid vehicle)
2 engine 3 motor 4 generator 5 battery 6 clutch 7 accelerator opening sensor 8 brake opening sensor 9 vehicle speed sensor 10 control device

Claims (4)

The engine,
A motor for driving the wheels and for regenerative braking;
a generator that generates electricity using a driving force of the engine and drives the engine;
a battery connected to the motor and the generator;
a control device that performs regenerative motoring control for supplying regenerative power of the motor to the generator when the vehicle is running and the accelerator is released, and motoring the engine at a predetermined target rotation speed,
A hybrid vehicle characterized in that the control device, when the accelerator is turned on while the regenerative motoring control is being performed, stops the regenerative motoring control and transitions the operating state of the engine from a motoring state to a firing state, and performs a first power generation control in which the generator generates power while firing the engine while keeping the engine rotation speed fixed at the target rotation speed at the time the accelerator was turned on. 2. The hybrid vehicle according to claim 1, wherein, during the first power generation control, the control device maintains the engine rotation speed while increasing the torque of the engine as an accelerator opening degree increases. 3. The hybrid vehicle according to claim 1, wherein the control device, when performing the first power generation control, stops the first power generation control and performs a second power generation control in which the engine rotation speed is increased when a driver requested output exceeds a predetermined value. The hybrid vehicle according to any one of claims 1 to 3, characterized in that, when the accelerator is released while the first power generation control is being performed, the control device resumes the regenerative motoring control and transitions the operating state of the engine from the firing state to the motoring state.