JP6971076B2 - Hybrid vehicle - Google Patents

Description

The present invention relates to a hybrid vehicle capable of traveling by using an engine and an electric motor as power sources.

Patent Document 1 describes a technique for torque-assisting an engine with a drive motor or generating electricity to increase an engine load in order to suppress a shock at the time of transition from a lean operation region to a stoichiometric operation region. It has been disclosed.

Japanese Unexamined Patent Publication No. 2008-08802

Although it is possible to suppress the shock when the engine shifts from the lean operating region to the stoichiometric operating region, there is a problem that rich spike fuel is required when shifting to the stoichiometric operating region, resulting in deterioration of fuel efficiency.
An object of the present invention is to provide a hybrid vehicle that suppresses a shock when shifting from an engine stop operation region or a lean combustion operation region to a stoichiometric combustion operation region and improves fuel efficiency.

In order to achieve the above object, in the hybrid vehicle of the present invention, the engine, the drive motor, and the drive that transmits the drive force of the engine to the drive wheels and the drive force of the drive motor to the drive wheels. In a hybrid vehicle including a force transmitting means and a driving force control unit that controls the driving force ratio of the engine and the driving force ratio of the driving motor by the driving force transmitting means according to a traveling state, the engine of the engine. An operating area switching means that can be switched between a stopped operation region, a lean combustion operating region where the air fuel ratio is lean, and a stoichiometric combustion operating region where the air fuel ratio is near stoichiometric is provided, and the operating region switching means corresponds to the required driving force. When it is determined to switch the operating region of the engine from the stopped operating region or the lean combustion operating region to the stoichiometric operating region, the driving force control unit determines that the engine is stoichiometrically combusted from the stopped operating region or the lean combustion operating region. with prohibits switching to the operating region, increases or decreases the driving force ratio of the driving motor so that the driving force and the total drive force obtained by combining the driving force of the driving motor of the engine becomes the required drive force, When the operating region switching means determines to switch the operating region of the engine to the lean combustion operating region in response to the required driving force, the driving force control unit stops the driving force of the driving motor. At the same time, it was decided to start the operating region of the engine in the lean combustion operating region.

Therefore, it is possible to suppress a shock when shifting from the FC operation region or the lean combustion operation region, which is the engine stop operation region, to the stoichiometric combustion operation region, and improve fuel efficiency.

FIG. 3 is an overall system diagram showing a rear-wheel drive hybrid vehicle of the first embodiment. It is a control block diagram which shows the arithmetic processing program in the integrated controller of Example 1. FIG. It is a figure which shows an example of the driver required torque map used for the driver required torque calculation in the driver required torque calculation part of FIG. It is a figure which shows the normal mode map used for the selection of the target mode in the mode selection part of FIG. It is a figure which shows an example of the target charge / discharge amount map used for the calculation of the target charge / discharge power in the target charge / discharge calculation unit of FIG. It is a driving area characteristic diagram of the engine to which Example 1 is applied. It is a time chart which shows the driving force control processing of the engine and the driving motor of Example 1. FIG. It is a time chart which shows the driving force control processing of the engine and the driving motor of a comparative example. It is a time chart which shows the driving force control processing of the engine and the driving motor of Example 2. FIG.

[Example 1]
FIG. 1 is an overall system diagram showing a hybrid vehicle driven by a rear wheel of the first embodiment. The drive system of the hybrid vehicle in the first embodiment includes an engine E which is an internal combustion engine, a first clutch CL1, a motor generator MG which functions as a drive motor, a second clutch CL2, and an automatic drive system which functions as a driving force transmission means. It has a transmission AT, a propeller shaft PS, a differential DF, a left drive shaft DSL, a right drive shaft DSR, a left rear wheel RL (driving wheel), and a right rear wheel RR (driving wheel). FL is the left front wheel and FR is the right front wheel.

The engine E is a gasoline engine, and the valve opening of a throttle valve (not shown) is controlled based on a control command from the engine controller 1 described later. A flywheel FW is provided on the engine output shaft. Further, the engine E has a motor SSG. This motor SSG is connected to the crankshaft of engine E using a belt, functions as a starter motor for starting the engine, and operates as an alternator that generates electricity as needed.
The first clutch CL1 is a dry clutch that is interposed between the engine E and the motor generator MG as a drive motor and can be always engaged by an urging force such as a diaphragm spring. Based on the control command, the control hydraulic pressure generated by the first clutch hydraulic unit 6 controls engagement / opening including slip engagement in which torque is transmitted while slipping.

The motor generator MG is a synchronous motor generator in which a permanent magnet is embedded in a rotor and a stator coil is wound around a stator. A three-phase alternating current generated by an inverter 3 is generated based on a control command from a motor controller 2 described later. It is controlled by applying. This motor generator MG can also operate as an electric motor that is driven to rotate by receiving electric power supplied from the battery 4 (hereinafter, this state is referred to as "power running"), and when the rotor is rotated by an external force. Can also function as a generator to generate electromotive force at both ends of the stator coil to charge the battery 4 (hereinafter, this operating state is referred to as "regeneration"). The rotor of this motor generator MG is connected to the input shaft of the automatic transmission AT via a damper (not shown).
The second clutch CL2 is a clutch interposed between the motor generator MG and the left and right rear wheels RL and RR, and was created by the AT hydraulic control unit 8 based on the control command from the AT controller 7, which will be described later. The control hydraulic control controls fastening and opening, including slip fastening, which transmits torque while slipping.

The automatic transmission AT is a transmission that automatically switches the stepwise gear ratio such as forward 7th speed and backward 1st speed according to the vehicle speed VSP, accelerator opening (driver's accelerator pedal operation) APO, and the like. The second clutch CL2 is not newly added as a dedicated clutch, but uses some friction fastening elements among a plurality of friction fastening elements fastened at each shift stage of the automatic transmission AT. The output shaft of the automatic transmission AT is connected to the left and right rear wheels RL and RR via the propeller shaft PS, the differential DF, the left drive shaft DSL, and the right drive shaft DSR as the vehicle drive shaft. For the first clutch CL1 and the second clutch CL2, for example, a multi-plate clutch capable of continuously controlling the oil flow rate and the oil pressure by a proportional solenoid is used.

This hybrid drive system has three traveling modes depending on the engaged / released state of the first clutch CL1. The first driving mode is an electric vehicle driving mode as a motor-using driving mode in which the vehicle travels using only the power of the motor generator MG as a power source in the open state of the first clutch CL1 (hereinafter, abbreviated as "EV driving mode"). Is. The second driving mode is an engine-using driving mode (hereinafter, abbreviated as "HEV driving mode") in which the engine E is included in the power source while the first clutch CL1 is engaged. The third traveling mode is an engine-using slip traveling mode (hereinafter, abbreviated as "WSC traveling mode") in which the second clutch CL2 is slip-controlled while the first clutch CL1 is engaged and the engine E is included in the power source. ). This mode is a mode in which creep running can be achieved, especially when the battery SOC is low or the engine water temperature is low.

The above-mentioned "HEV driving mode" has three driving modes of "engine driving mode", "motor assisted driving mode", and "driving power generation mode". In the "engine driving mode", the drive wheels are driven only by the engine E as a power source. In the "motor-assisted driving mode", the drive wheels are driven by two power sources, the engine E and the motor generator MG. In the "running power generation mode", the drive wheels RR and RL are driven by the engine E as a power source, and at the same time, the motor generator MG is made to function as a generator. During constant speed operation or acceleration operation, the motor generator MG is operated as a generator by using the power of the engine E. Also, during deceleration operation, braking energy is regenerated to generate electricity with the motor generator MG, which is used to charge the battery 4. Further, when the vehicle is stopped, it has a power generation mode in which the motor generator MG is operated as a generator by using the power of the engine E.

Next, the control system of the hybrid vehicle will be described. As shown in FIG. 1, the control system of the hybrid vehicle in the first embodiment includes an engine controller 1, a motor controller 2, an inverter 3, a battery 4, a first clutch controller 5, and a first clutch hydraulic unit 6. , AT controller 7, AT hydraulic control unit 8, brake controller 9, integrated controller 10, and SSG controller SSGCU. The engine controller 1, the motor controller 2, the first clutch controller 5, the AT controller 7, the brake controller 9, the integrated controller 10, and the SSG controller SSGCU have a CAN communication line 11 that can exchange information with each other. It is connected via.

Based on the target engine torque command from the integrated controller 10 based on the required driving force, the engine controller 1 has a lean combustion operation region in which the FC operation region, which is a stop operation region, and the air-fuel ratio are lean, and a stoichiometric region in which the air-fuel ratio is in the vicinity of stoichiometry. The operation area switching means 1a for switching to the combustion operation area is provided.
Further, the engine controller 1 inputs the discrimination cylinder from the cylinder discrimination sensor 32 and the engine rotation speed information from the engine rotation speed sensor 12, and responds to the target engine torque command from the integrated controller 10 and the engine operating point (Ne: A command for controlling engine speed (Te: engine torque) is output to, for example, a throttle actuator that controls the throttle opening of a throttle valve (not shown). Information such as the accelerator opening APO, engine speed Ne, current operating area, switching target operating area, and discrimination cylinder is supplied to the integrated controller 10 via the CAN communication line 11.
The SSG controller SSGCU outputs a command to operate the motor SSG as a starter motor function and an alternator function based on the command signal from the integrated controller 10.

The motor controller 2 inputs information from the resolver 13 that detects the rotor rotation position of the motor generator MG, and issues a command to control the motor operating point of the motor generator MG in response to a target motor torque command or the like from the integrated controller 10. Output to 3. This motor controller 2 monitors the battery SOC, which indicates the state of charge of the battery 4. The monitored battery SOC information is used for the control information of the motor generator MG and is supplied to the integrated controller 10 via the CAN communication line 11.

The first clutch controller 5 inputs sensor information from the first clutch oil pressure sensor 14 and the first clutch stroke sensor 15 and a first clutch control command from the integrated controller 10, and the first clutch is input to the first clutch oil pressure unit 6. Outputs the CL1 engagement / opening control command. The information of the first clutch stroke C1S is supplied to the integrated controller 10 via the CAN communication line 11.

The AT controller 7 is from the accelerator pedal opening sensor 16, the vehicle speed sensor 17, the second clutch oil pressure sensor 18, the various sensor signals of the inhibitor switch 28 that outputs the range signal according to the operation position of the select lever 27, and the integrated controller 10. The control command of is input, and the control command is output to the AT hydraulic control unit 8. The accelerator opening APO, vehicle speed VSP, and inhibitor switch signal are supplied to the integrated controller 10 via the CAN communication line 11. Further, the inhibitor switch signal is sent to the in-meter display 29 provided in the combination meter (not shown), and the current range position is displayed.

The brake controller 9 inputs sensor information from the wheel speed sensor 19 and the brake stroke sensor 20 that detect the speed of each of the four wheels. Then, at the time of depressing the brake, based on the regenerative coordinated control command from the integrated controller 10, the shortage of the regenerative braking force is compensated for by the mechanical braking force (braking force by the friction brake) with respect to the required braking force required from the brake stroke BS. Performs regenerative braking control.

The integrated controller 10 is a controller for managing the energy consumption of the entire vehicle and running the vehicle with the highest efficiency. The motor rotation sensor 21 that detects the motor rotation speed Nm and the second clutch output rotation speed N2out are detected. The second clutch output rotation speed sensor 22, the second clutch torque sensor 23 that detects the second clutch transmission torque capacity TCL2, the brake oil pressure sensor 24, the temperature sensor 25 that detects the temperature of the second clutch CL2, and the front and rear. Information obtained via the G sensor 26 that detects acceleration, the first clutch temperature sensor 30, the inverter temperature sensor 31, and the CAN communication line 11 is input.

Further, the integrated controller 10 controls the operation of the engine E by a control command to the engine controller 1, controls the operation of the motor generator MG which is a drive motor by a control command to the motor controller 2, and controls the operation of the first clutch controller 5. The engagement / release control of the first clutch CL1 by the control command, the engagement / release control of the second clutch CL2 by the control command to the AT controller 7, and the starter motor function or the alternator function by the control command to the SSG controller SSGCU are exhibited. Motor control and.

FIG. 2 is a control block diagram showing a control configuration in the integrated controller 10 of the first embodiment. The integrated controller 10 executes various operations with a control cycle of, for example, 10 msec. The integrated controller 10 includes a driver required torque calculation unit 100, a mode selection unit 200, a target charge / discharge calculation unit 300, an operating point command unit 400 including a driving force control unit 10a, and a shift control unit 500.

The driver required torque calculation unit 100 calculates the driver required torque Tdd, which is the required driving force, from the accelerator pedal opening APO and the vehicle speed VSP using the driver required torque map shown in FIG.

Next, the mode map will be described. FIG. 4 is a normal mode map of the first embodiment. The normal mode map has an EV driving mode, a WSC driving mode, and an HEV driving mode, and the target mode is calculated from the accelerator pedal opening APO and the vehicle speed VSP. This mode map outputs a mode corresponding to the position of the driving point determined by the accelerator pedal opening APO and the vehicle speed VSP as the target mode. However, even if the EV driving mode is selected, if the battery SOC is below a predetermined value or there is another idling stop prohibition request, the "HEV driving mode" is forcibly set as the target mode.

In the normal mode map of FIG. 4, the WSC → EV switching line and the HEV → EV switching line are set to a predetermined opening APO2 when viewed on the accelerator pedal opening APO axis. Further, the HEV → EV switching line is set to a predetermined vehicle speed VSP2 when viewed on the vehicle speed VSP axis. The HEV → WSC switching line has a vehicle speed that is smaller than the lower limit vehicle speed VSP1 that matches the idle speed of the engine E when the automatic transmission AT is in the 1st speed in the region where the predetermined accelerator pedal opening is less than APO1. It is set in the area. Further, since a large driving force is required in the region where the predetermined accelerator pedal opening APO1 or more, the WSC driving mode is set up to the vehicle speed VSP1'region higher than the lower limit vehicle speed VSP1. When the battery SOC is low and the EV driving mode cannot be achieved, the WSC driving mode is set to be selected even when starting.

When the accelerator pedal opening APO is large, it may be difficult to meet the requirement with the engine torque Te and the motor generator torque Tmg corresponding to the engine speed near the idle speed. Here, the engine torque Te can output more torque if the engine speed Ne increases. From this, the engine speed Ne is increased to output a larger torque. Therefore, even if the WSC driving mode is executed to a vehicle speed higher than the lower limit vehicle speed VSP1, the transition from the WSC driving mode to the HEV driving mode can be performed in a short time. This case is the WSC region expanded to the lower limit vehicle speed VSP1'shown in FIG.

The target charge / discharge calculation unit 300 calculates the target charge / discharge power from the battery SOC using the target charge / discharge amount map shown in FIG.
In the operating point command unit 400, the drive provided in the operating point command unit 400 is set as the operating point arrival target from the accelerator opening APO, the driver required torque Tdd, the target mode, the vehicle speed VSP, and the target charge / discharge power. The force control unit 10a controls the driving force ratio of the engine E and the driving force ratio of the motor generator MG, which is the driving motor, of the driving force transmitted to the driving wheels RR and RL, and transiently targets the engine torque and the target motor. The generator torque, the target second clutch transmission torque capacity, the target shift stage of the automatic transmission AT, and the first clutch solenoid current command are calculated and commanded.
Further, the driving force control unit 10a controls the driving force ratio of the engine E and the driving force ratio of the motor generator MG which is a driving motor, and is based on the information obtained from the engine controller 1 via the CAN communication line 11. When the operation area information to be switched is the stoichiometric operation area, the stoichiometric operation area prohibition command is output to the operation mode switching means 1a of the engine control 1, and the motor generator MG, which is a drive motor, uses the required driving force. The excess or deficiency of a certain driver required torque Tdd is adjusted and calculated, and the target motor generator torque is calculated and output to the motor generator MG. Details will be described later.

Further, the operating point command unit 400 has an engine start control unit that starts the engine E when transitioning from the EV drive mode to the HEV drive mode. The engine start control unit sets the second clutch CL2 to the second clutch transmission torque capacity corresponding to the driver required torque Tdd, and puts it in the slip control state. Further, the motor generator MG is used for rotation speed control, and the target motor generator rotation speed is set to a value obtained by adding a predetermined slip amount to a value equivalent to the drive wheel rotation speed. In this state, the engine start control unit outputs a command to the SSG controller SSGCU to function as a starter motor, and releases the first clutch CL1. As a result, engine cranking that suppresses the heat generation of the first clutch CL1 is performed. The details of the mode transition will be described later. Then, after cranking by the motor SSG, a engagement command is output to the first clutch CL1. As a result, the engine is started.
The shift control unit 500 drives and controls the solenoid valve in the automatic transmission AT so as to achieve the target second clutch transmission torque capacity and the target shift stage according to the shift schedule shown in the shift map. In the shift map, the target shift stage is set in advance based on the vehicle speed VSP and the accelerator pedal opening APO.

Next, the operating area switching means 1a is the engine E and the driving motor when the operating area information to be switched determined based on the target engine torque command from the integrated controller 10 based on the required driving force is the stoichiometric operation area. The driving force control process of a certain motor generator MG will be described. FIG. 6 is an operating region characteristic diagram of the engine applied to the first embodiment.

The vertical axis represents the engine torque, which is the driving force of the engine, and the horizontal axis represents the engine rotation. The area surrounded by the broken line where the engine torque on the vertical axis is negative indicates the FC (fuel cut) operating area which is the stopped operation area of the engine E, and the area where the engine torque is positive is surrounded by the alternate long and short dash line. A low-torque stoichiometric operation region with a relatively small torque, a high-torque stoichiometric operation region with a large torque surrounded by a broken line, and a lean operating region surrounded by a solid line are shown at the center thereof.
That is, there are an FC operation region, a low torque stoichiometric operation region, and a high torque stoichiometric operation region corresponding to the engine torque which is the required driving force for the engine E.

FIG. 7 is a time chart showing the driving force control process of the engine and the driving motor of the first embodiment.
In the time chart above, the horizontal axis is time, and the vehicle speed VSP indicated by the broken line, the engine speed Ne indicated by the alternate long and short dash line, and the change in the accelerator opening APO are shown.
In the time chart below, the vertical axis on the left shows the engine torque that is the driving force of the engine and the torque that is the driving force of the motor generator MG, and the vertical axis on the right shows the operating area of the engine E and the operating area of the motor generator MG. ..
The horizontal axis is time, which is the engine torque and operating area, which is the engine driving force shown by the broken line, the torque and operating area, which is the driving force of the motor generator MG shown by the solid line, and the total drive of the engine E + motor generator MG shown by the alternate long and short dash line. It shows the change in force, that is, the total torque.

From time t0 to t1, the accelerator opening APO is closed, and the vehicle is in the coastal state and decelerating.
Further, the engine E is in the FC operation region (stop operation region), and the motor generator MG is also in the power generation region, and each generates a negative driving force, that is, a negative torque.
The engine rotation Ne is a constant rotation.
At time t1, the accelerator is depressed, the accelerator opening is opened at a low opening, and the drive state is entered. Here, in order to generate the accelerator opening, that is, the driver required torque Tdd, which is the required driving force, when the operating area switching means 1a of the engine controller 1 determines that the engine E shifts to the stoichiometric operation area, the integrated controller 10 is used. In order to avoid fuel rich spikes, the driving force control unit 10a issues an engine operating area command to maintain the FC operating area by prohibiting the transition to the stoichiometric operating area, and the engine E maintains the FC operating area.
Further, the driving force control unit 10a of the integrated controller 10 adds the insufficient driving force by stopping the engine E, and commands a positive driving force, that is, a positive torque to the motor generator MG corresponding to the required driving force.
As a result, the total torque, which is the combined total driving force, is shown by the alternate long and short dash line, and when viewed only from the engine E, it becomes the torque in the stoichiometric operation range.

At time t2, the accelerator is further depressed, the accelerator opening is opened at a higher opening, and the driver required torque Tdd, which is the required driving force, increases.
Here, in order to satisfy the increased driver required torque Tdd, if the driving force control unit 10a of the integrated controller 10 increases the engine torque, which is the driving force of the engine E, and responds, it is determined that the engine shifts to the stoichiometric operation region. The engine commands an increase in the positive driving force, or positive torque, of the motor generator MG while maintaining the FC operating range.

At time t3, the driving force control unit 10a of the integrated controller 10 determines that it is achievable in the lean operating region of engine E in order to satisfy the increased driver required torque Tdd, stops the motor generator MG, and leans engine E. It commands the start of engine E to generate a positive driving force, or positive torque, in the operating area.
As a result, the total torque, which is the combined total driving force, is shown by the alternate long and short dash line, and becomes the torque only in the lean operation region of the engine E that satisfies the driver required torque Tdd.

FIG. 8 is a time chart showing the driving force control processing of the engine and the driving motor of the comparative example.

Similar to the first embodiment, from time t0 to t1, the accelerator opening APO is closed, and the vehicle is in a coastal state and decelerates.
Further, the engine E is in the FC operation region (stop operation region), and the motor generator MG is also in the power generation operation region, and each generates a negative driving force (negative torque).
The engine rotation Ne is a constant rotation.
At time t1, the accelerator is depressed, the accelerator opening is opened at a low opening, and the drive state is entered. Here, in order to generate the accelerator opening, that is, the driver required torque Tdd which is the required driving force, when the operating area switching means 1a of the engine controller 1 determines that the engine E shifts to the stoichiometric operation area, the motor generator MG is used. The engine operation area command is issued to the stop operation area, the rich spike of fuel and the transition to the stoichiometric operation area, the motor generator MG is stopped, and the engine E shifts to the stoichiometric operation area.
Therefore, in the comparative example, when the engine E shifts to the stoichiometric operation region, a rich spike of fuel is performed, which causes a shock and deterioration of fuel efficiency.

As described above, in Example 1, the following effects can be obtained.
(1) The engine E, the motor generator MG which is a driving motor, and the driving force transmitting means for transmitting the driving force of the engine E to the driving wheels RR and RL and also transmitting the driving force of the motor generator MG to the driving wheels. In a hybrid vehicle equipped with an automatic transmission AT and a driving force control unit 10a that controls the driving force ratio of the engine E and the motor generator MG driving force ratio by the automatic transmission AT according to the driving condition.
An operating region switching means 1a that can switch between the FC operating region, which is the stopped operating region of the engine E, the lean combustion operating region in which the air-fuel ratio is lean, and the stoichiometric combustion operating region in which the air-fuel ratio is near the stoichiometric region is provided. When 1a determines to switch the operating region of engine E from the FC operating region to the stoichiometric combustion operating region in response to the required driving force, the driving force control unit 10a starts the stoichiometric combustion operation from the FC operating region of engine E. While prohibiting switching to the region, the FC operating region of engine E is maintained, and the total driving force that combines the negative driving force of engine E and the positive driving force of the motor generator MG becomes the required driving force. Increase the driving force ratio of the motor generator MG.
Therefore, the engine can maintain the FC operating region, which is the stopped operating region, suppress the shock when shifting to the stoichiometric combustion operating region, improve the drivability, and improve the fuel efficiency.

(2) When the operating region switching means 1a determines that the operating region of the engine E is switched to the lean burning operating region in response to the required driving force, the driving force output control means 10a is driven by the motor generator MG. And start the operating area of engine E in the lean burning operating area.
Therefore, by performing the operating region of the engine E in the lean combustion operating region and stopping the motor generator MG, the energy management of the battery 4 can be optimized, the consumption of the charged state of the battery 4 can be suppressed, and the fuel consumption can be suppressed. Can be improved.

FIG. 9 is a time chart showing the driving force control process of the engine and the driving motor of the second embodiment.

Similar to FIG. 7, in the above time chart, the horizontal axis is time, and the vehicle speed VSP indicated by the broken line, the engine speed Ne indicated by the alternate long and short dash line, and the change in the accelerator opening APO are shown.
In the time chart below, the vertical axis on the left shows the engine torque that is the driving force of the engine and the torque that is the driving force of the motor generator MG, and the vertical axis on the right shows the operating area of the engine E and the operating area of the motor generator MG. ..
The horizontal axis is time, which is the engine torque and operating area, which is the engine driving force shown by the broken line, the torque and operating area, which is the driving force of the motor generator MG shown by the solid line, and the total drive of the engine E + motor generator MG shown by the alternate long and short dash line. It shows the change in force, that is, the total torque.

From time t0 to t1, the accelerator opening APO is closed, and the vehicle is in the coastal state and decelerating.
Further, the engine E is in the FC operation region (stop operation region), and the motor generator MG is also in the power generation operation region, and each generates a negative driving force (negative torque).
The engine rotation Ne is a constant rotation.
At time t1, the accelerator is depressed, the accelerator opening is opened at a low opening, and the drive state is entered. Here, in order to generate the accelerator opening, that is, the driver required torque Tdd, which is the required driving force, when the operating area switching means 1a of the engine controller 1 determines that the engine E shifts to the stoichiometric operation area, the integrated controller 10 is used. In order to avoid the rich spike of fuel, the driving force control unit 10a issues an engine operation area command for the transition to the lean operation area by prohibiting the transition to the stoichiometric operation area, and the engine E shifts to the lean operation area.
Further, the driving force control unit 10a of the integrated controller 10 subtracts the increasing driving force (torque) of the engine E due to the shift of the engine E to the lean operating region, and negatively affects the motor generator MG corresponding to the required driving force. It commands an increase in the driving force, that is, the negative torque (power generation amount).
As a result, the total torque, which is the combined total driving force, is shown by the alternate long and short dash line, and when viewed only from the engine E, it becomes the torque in the stoichiometric operation range.

At time t2, the accelerator is further depressed, the accelerator opening is opened at a higher opening, and the driver required torque Tdd, which is the required driving force, increases.
Here, in order to satisfy the increased driver required torque Tdd, the driving force control unit 10a of the integrated controller 10 increases the engine torque, which is the driving force in the lean operating region of the engine E, so that the engine E alone can handle it. Judging, the engine increases the engine torque while maintaining the lean operating range, and orders the motor generator MG to stop.

As described above, even in the second embodiment, the same action and effect as in the first embodiment can be obtained.

[Other Examples]
Although the present invention has been described above based on the examples, the specific configuration may be another configuration. For example, in the embodiment, the FR type hybrid vehicle has been described, but the FF type hybrid vehicle may be used.
Further, when switching from the lean operation region of the engine E to the stoichiometric operation region of low torque, the engine E may be shifted to the FC operation region and the positive driving force (positive torque) by the motor generator MG may be increased. However, the lean operating region of the engine E may be maintained, and a negative driving force, that is, a negative torque (power generation) may be generated by the motor generator MG.
Further, when switching from the lean operating region of the engine E to the high torque stoichiometric operating region, the lean operating region of the engine E may be maintained and the positive driving force (positive torque) by the motor generator MG may be increased.

1 engine controller
1a Operating area switching means
2 motor controller
10 integrated controller
10a Driving force control unit
AT automatic transmission (driving force transmission means)
CL1 1st clutch
CL2 2nd clutch
E engine
MG motor generator (drive motor)
RR, RL drive wheels

Claims (2)

An engine, a driving motor, a driving force transmitting means for transmitting the driving force of the engine to the driving wheels, and a driving force transmitting means for transmitting the driving force of the driving motor to the driving wheels.
A driving force control unit that controls the driving force ratio of the engine and the driving force ratio of the driving motor by the driving force transmitting means according to the traveling state.
In a hybrid vehicle equipped with
An operating region switching means capable of switching between a stopped operation region of the engine, a lean combustion operating region in which the air-fuel ratio is lean, and a stoichiometric combustion operating region in which the air-fuel ratio is in the vicinity of stoichiometric is provided.
When the operating area switching means, which determine the switching of the operating region of the engine from stopping operating region or the lean burn operation area to the stoichiometric combustion operating region in response to the required driving force,
The driving force control unit prohibits the engine from switching from the stopped operation region or the lean combustion operation region to the stoichiometric combustion operation region, and is a total drive that combines the driving force of the engine and the driving force of the driving motor. the driving force ratio of the driving motor to increase or decrease such that a force is required driving force,
When the operating region switching means determines to switch the operating region of the engine to the lean burning operating region in response to the required driving force,
The driving force control unit stops the driving force of the driving motor and starts the operating region of the engine in the lean combustion operating region.
A hybrid vehicle that features that. An engine, a driving motor, a driving force transmitting means for transmitting the driving force of the engine to the driving wheels, and a driving force transmitting means for transmitting the driving force of the driving motor to the driving wheels.
A driving force control unit that controls the driving force ratio of the engine and the driving force ratio of the driving motor by the driving force transmitting means according to the traveling state.
In a hybrid vehicle equipped with
An operating region switching means capable of switching between a stopped operation region of the engine, a lean combustion operating region in which the air-fuel ratio is lean, and a stoichiometric combustion operating region in which the air-fuel ratio is in the vicinity of stoichiometric is provided.
When the operating region switching means determines to switch the operating region of the engine from the stopped operating region or the lean combustion operating region to the stoichiometric combustion operating region in response to the required driving force,
The driving force control unit prohibits the engine from switching from the stopped operation region or the lean combustion operation region to the stoichiometric combustion operation region, and is a total drive that combines the driving force of the engine and the driving force of the driving motor. Increase or decrease the driving force ratio of the driving motor so that the force becomes the required driving force.
When the operating region switching means determines to switch the operating region of the engine to the lean burning operating region in response to the required driving force,
The driving force control unit increases the negative driving force of the driving motor and starts the operating region of the engine in the lean combustion operating region.
A hybrid vehicle that features that.

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