JP2023076484A - Control device for hybrid vehicle - Google Patents

Abstract

To achieve a response matching the intention of a driver who requires quick acceleration in a hybrid vehicle.SOLUTION: A control device controls a hybrid vehicle which includes: a traveling electric motor capable of supplying driving force for traveling to driving wheels; an internal combustion engine capable of supplying driving force for power generation to a power generator for generating power to be supplied to the traveling electric motor; and a motoring electric motor capable of supplying driving force for rotating the internal combustion engine to the internal combustion engine. Under a situation where the traveling electric motor is rotated together with the driving wheels and is performing regenerative power generation, the control device for the hybrid vehicle executes control to: perform the motoring of the internal combustion engine by using the motoring electric motor if the amount of charge stored in an on-vehicle power storage device is equal to or greater than a threshold; and if the amount of charge stored in the on-vehicle power storage device is below the threshold, bring the internal combustion engine into idle operation or a low-load operation state close to the idle operation while firing the internal combustion engine, and charge the power storage device with at least part of power generated by the regenerative power generation.SELECTED DRAWING: Figure 4

Description

The present invention relates to a control device for controlling a hybrid vehicle equipped with an electric motor for running and an internal combustion engine.

2. Description of the Related Art Recently, hybrid vehicles equipped with two types of power sources, an electric motor and an internal combustion engine, are gaining popularity. A series-type hybrid vehicle (see, for example, the following patent document) generates power by driving a power generation motor generator with an internal combustion engine, and stores the generated power in a power storage device, such as a lithium ion secondary battery or a nickel metal hydride secondary battery. It is stored in a battery and/or a capacitor, etc., and supplied to a motor-generator for running. Then, the driving wheels of the vehicle are rotated by the motor generator for traveling to travel.

Not only the motor-generator for power generation but also the motor-generator for traveling can generate power by regenerative braking, and the generated power can be stored in the power storage device. When electric charge is already stored up to the capacity of the power storage device, the electric power obtained by regenerative braking is intentionally supplied to the motor generator for power generation, and this is operated as an electric motor to perform motoring to rotationally drive the internal combustion engine. This consumes excess power.

In a hybrid vehicle, the vehicle can be driven by the rotational driving force output from the motor generator for traveling without firing the internal combustion engine to generate the rotational driving force by burning the fuel. Therefore, even during operation of the vehicle, the state where the rotation of the internal combustion engine is stopped may continue.

When the amount of electric charge stored in the power storage device decreases, or when the required output of the traction motor generator is large, the internal combustion engine is started, fuel is supplied to the cylinders, and the fuel is combusted, and the internal combustion engine outputs rotational drive. The electric power is used to drive the electric power generation motor generator, and electric power is generated to charge the power storage device or increase electric power supplied to the running motor generator.

In a series-system hybrid vehicle, the motor generator for power generation also serves to motor (or crank) the internal combustion engine in preparation for starting the stopped internal combustion engine. During motoring, the required power is supplied from the power storage device.

JP 2019-131035 A

When the internal combustion engine is started to generate power, the internal combustion engine is motored by the motor generator for power generation to accelerate the engine speed to a required speed (for example, 600 rpm), and then fuel is supplied to the cylinders of the internal combustion engine. to start ignition combustion of fuel in the internal combustion engine. Furthermore, motoring is continued to raise the engine speed to an efficient speed (for example, 2000 rpm), then motoring is terminated, and the internal combustion engine drives the generator motor generator to start generating power.

In other words, there is a time lag between the state in which the internal combustion engine is stopped and the state in which the internal combustion engine burns fuel, rotates independently, and can supply driving force to the generator. When the driver who wants to accelerate the vehicle depresses the accelerator pedal and the required output of the traction motor generator increases, if the rotation of the internal combustion engine is stopped, the motor generator for power generation is quickly switched from the motor generator for traction. There is a possibility that power cannot be supplied to the device and a response that meets the request cannot be realized.

In particular, when the power storage device installed in the vehicle has a small capacity, the motor generator for running is necessary and sufficient for the period until the motor generator for power generation actually starts power generation after the acceleration request by the driver. It will not be possible to output a large driving force, and you will feel that the acceleration is sluggish. During this period, electric power is exclusively supplied from the power storage device to the motor generator for running, but for the convenience of motoring for starting the internal combustion engine, the necessary power is also supplied from the same power storage device to the motor generator for power generation. There must be. Since the maximum electric power that can be output by the power storage device is small, the electric power to be supplied to the motor generator for traveling is not sufficient, and the driving force output by the motor generator for traveling is inevitably suppressed to a low level.

SUMMARY OF THE INVENTION An intended object of the present invention is to realize a response that matches the driver's intention to request quick acceleration.

In the present invention, an electric motor for traveling that can supply driving force for traveling to drive wheels, an internal combustion engine that can supply driving force for power generation to a generator that generates electric power to be supplied to the electric motor for traveling, and an internal combustion engine. and a motoring electric motor capable of supplying a driving force for rotating the internal combustion engine to a hybrid vehicle, wherein the traveling electric motor is rotated by the drive wheels to generate regenerative power. If the amount of electric charge stored in the electric storage device mounted on the vehicle is greater than or equal to the threshold value, the internal combustion engine is motored by the motoring electric motor, and if it is less than the threshold value, the internal combustion engine is fired while idling. Alternatively, a control device for a hybrid vehicle is configured that executes control to bring the vehicle into a low-load operating state close to idling and to charge at least part of the regeneratively generated electric power to a power storage device.

Motoring occurs when the traction motor drives the drive wheels for power running, and the electric power that can be output by the in-vehicle power storage device becomes the power consumed by the traction motor for powering. If the electric charge stored in the electric storage device is equal to or greater than the threshold value, the internal combustion engine is fired while the internal combustion engine is kept in idle operation or idling. A low-load operating state close to operation causes the generator to generate little or no power, and if the threshold is below the threshold, fires the internal combustion engine to cause the generator to generate power, and at least part of the generated power is charged to the power storage device. It is preferable to perform control to

In addition, when the traction motor drives the drive wheels for power running, and the electric power that can be output by the on-vehicle power storage device becomes necessary to motor the internal combustion engine with the power consumed by the traction motor for powering. A mode in which the current driving mode selected by the driver places more emphasis on fuel efficiency than vehicle driving performance under circumstances where the power input to the motoring motor exceeds the amount taken into account. If the current vehicle speed is lower than a predetermined value, the internal combustion engine is stopped. It is also preferred to fire the internal combustion engine if is higher than a predetermined value.

According to the present invention, in a hybrid vehicle, it is possible to realize a response that matches the intention of the driver requesting quick acceleration.

1 is a diagram showing a schematic configuration of a series hybrid vehicle and a control device according to an embodiment of the present invention; FIG. The figure which shows the outline|summary of the internal combustion engine mounted in the hybrid vehicle of the same embodiment. FIG. 4 is a flow diagram showing an example of the procedure of processing executed by the control device according to the embodiment according to the program; FIG. 4 is a flow diagram showing an example of the procedure of processing executed by the control device according to the embodiment according to the program; FIG. 4 is a timing chart illustrating how control is performed by the control device of the embodiment;

One embodiment of the present invention will be described with reference to the drawings. FIG. 1 shows a schematic configuration of main systems of a hybrid vehicle in this embodiment. This hybrid vehicle includes an internal combustion engine 1, a power generating motor generator 2 that is driven by the internal combustion engine 1 to generate power, a power storage device 3 that stores the electric power generated by the power generating motor generator 2, the power generating motor generator 2 and/or Alternatively, it is provided with a traveling motor generator 4 that receives electric power supply from the power storage device 3 to drive the driving wheels 62 of the vehicle.

The hybrid vehicle of the present embodiment is a series hybrid electric vehicle that uses the internal combustion engine 1 only for power generation, and the drive wheels 62 of the vehicle are exclusively supplied with driving force for running from the motor generator 4 for running. The internal combustion engine 1 and the drive wheels 62 are mechanically separated from each other, and originally rotational driving force is not transmitted between them. In other words, the internal combustion engine 1 can rotate completely independently of the motor generator 4 for traveling and the drive wheels 62, and can stop completely independently. Therefore, during operation of the vehicle in which the ignition switch (power switch or ignition key) is turned on, even if the vehicle is ready to run by depressing the accelerator pedal, the power storage device 3 is sufficiently charged. Under the condition that the electric charge is accumulated and the brake booster 15 has accumulated a sufficient negative pressure, the operation of the internal combustion engine 1 involving fuel combustion may not be performed.

A crankshaft, which is a rotating shaft of the internal combustion engine 1, is mechanically connected to a rotating shaft of a motor generator 2 for power generation via a gear mechanism. By inputting the rotational driving force output by the internal combustion engine 1 to the electric power generating motor generator 2, the electric power generating motor generator 2 generates electric power. The generated electric power is charged in the power storage device 3 and/or supplied to the traveling motor generator 4 . The power generation motor generator 2 also functions as an electric motor for motoring, which itself generates rotational driving force to rotationally drive the crankshaft of the internal combustion engine 1 . For example, the power generation motor generator 2 performs motoring (cranking) as preparation for starting the stopped internal combustion engine 1 .

The running motor generator 4 generates driving force for running the vehicle, and inputs the driving force to the drive wheels 62 via the speed reducer 61 . In addition, the running motor generator 4 rotates together with the drive wheels 62 to generate electric power, and recovers the kinetic energy of the vehicle as electric energy. The electric power generated by this regenerative braking charges the power storage device 3 .

Of course, if electric charge is already stored up to the capacity of the power storage device 3 and further charging is difficult, the electric power regenerated by the traveling motor generator 4 is intentionally supplied to the electric power generating motor generator 2 to generate electric power. The internal combustion engine 1 is rotationally driven by operating the motor generator 2 as an electric motor. This consumes excess electric power while maintaining the braking performance of the vehicle. Further, at this time, since the rotation of the internal combustion engine 1 is maintained, fuel cut can be executed to temporarily stop the supply of fuel to the cylinders of the internal combustion engine 1 .

The power generator inverter 21 converts the AC power generated by the power generation motor generator 2 into DC power. Then, the DC power is input to power storage device 3 or drive inverter 41 . In addition, when the power generation motor generator 2 is operated as an electric motor, the power generator inverter 21 converts the DC power supplied from the power storage device 3 and/or the drive inverter 41 into AC power, and then converts the power generation motor generator 2 into AC power. to enter.

The drive inverter 41 converts the DC power supplied from the power storage device 3 and/or the generator inverter 21 into AC power and inputs the AC power to the motor generator 4 for running. In addition, the drive inverter 41 converts AC power generated by the traveling motor generator 4 when the vehicle is regeneratively braked into DC power and inputs the DC power to the power storage device 3 or the generator inverter 21 . The generator inverter 21 and the drive inverter 41 form part of a PCU (Power Control Unit).

The power storage device 3 is a battery and/or a capacitor or the like. The battery is a high-voltage secondary battery with high energy density, such as a lithium-ion secondary battery or a nickel-hydrogen secondary battery. The power storage device 3 charges and stores electric power generated by each of the motor generator 2 for power generation and the motor generator 4 for running. Power storage device 3 also discharges electric power for operating motor generator 2 for electric power generation and motor generator 4 for running as electric motors, and supplies necessary electric power to motor generators 2 and 4 .

FIG. 2 shows an outline of the internal combustion engine 1 mounted on the hybrid vehicle of this embodiment. The internal combustion engine 1 is a spark-ignited four-stroke engine, and includes a plurality of cylinders 11 (eg, three cylinders, one of which is shown in FIG. 1). An injector 111 for injecting fuel toward the intake port is provided near the intake port of each cylinder 11 . A spark plug 112 is attached to the ceiling of the combustion chamber of each cylinder 11 . The spark plug 112 receives an induced voltage generated by the ignition coil and induces spark discharge between the center electrode and the ground electrode.

An intake passage 13 for supplying intake air takes in air from the outside and guides it to the intake port of each cylinder 11 . An air cleaner 131, an electronic throttle valve 132, a surge tank 133, and an intake manifold 134 are arranged in this order on the intake passage 13 from upstream. The air cleaner 131 is located at the most upstream position in the intake passage 13, that is, at the intake port that takes in air. The air intake opens to the front of the vehicle to take in cool air and increase the charging efficiency of the internal combustion engine.

An exhaust passage 14 for exhausting exhaust guides the exhaust generated as a result of burning fuel in the cylinder 11 from the exhaust port of each cylinder 11 to the outside. An exhaust manifold 142 and a three-way catalyst 141 for purifying exhaust gas are arranged on the exhaust passage 14 .

An external EGR (Exhaust Gas Recirculation) device 12 implements so-called high pressure loop EGR. The EGR device 12 includes an external EGR passage 121 that communicates the upstream side of the catalyst 141 in the exhaust passage 14 and the downstream side of the throttle valve 132 in the intake passage 13, an EGR cooler 122 provided on the EGR passage 121, and the EGR passage 121. and an EGR valve 123 that opens and closes the EGR passage 121 to control the flow rate of EGR gas flowing through the EGR passage 121 . The inlet of the EGR passage 121 is connected to the exhaust manifold 142 in the exhaust passage 14 or a predetermined location downstream thereof. An outlet of the EGR passage 121 is connected to a predetermined location downstream of the throttle valve 132 in the intake passage 13 , specifically, a surge tank 133 .

The internal combustion engine 1 is provided with a brake booster 15 for reducing the operating force required for braking the vehicle, that is, the force applied to the brake pedal. The brake booster 15 introduces intake negative pressure from a portion (or a surge tank 133) downstream of the throttle valve 132 in the intake passage 13, and uses the negative pressure to boost the depression force of the brake pedal. It is widely known. The brake booster 15 has a constant pressure chamber (negative pressure chamber) that stores negative pressure and a variable pressure chamber (atmospheric pressure chamber) to which atmospheric pressure is applied. ing. The negative pressure line 151 guides the intake negative pressure on the downstream side of the throttle valve 132 to the constant pressure chamber. A check valve 152 is provided on the negative pressure line 151 to retain the negative pressure in the constant pressure chamber and prevent the positive pressure from being applied to the constant pressure chamber.

When the driver does not operate the brake pedal, the constant pressure chamber communicates with the variable pressure chamber, and the variable pressure chamber is isolated from the atmospheric pressure. When the brake pedal is operated, the constant pressure chamber and the variable pressure chamber are cut off, and air is introduced into the variable pressure chamber. As a result, the pressure difference between the constant pressure chamber and the variable pressure chamber becomes the control pressure that boosts the force applied to the brake pedal. The brake depression force amplified by the brake booster 15 is converted into hydraulic pressure in the master cylinder 16 . The master cylinder pressure output by the master cylinder 16, that is, the pressure of the brake fluid discharged by the master cylinder 16 is transmitted to a brake device such as a brake caliper or a wheel cylinder via a hydraulic circuit, and is used for braking the vehicle by the brake device. Used.

An ECU (Electronic Control Unit) 0, which is a control device for controlling the internal combustion engine 1, the motor generator 2 for power generation, the power storage device 3, the inverters 21 and 41, and the motor generator 4 for running, includes a processor, a memory, an input interface, an output interface, and the like. It is a microcomputer system having The ECU 0 includes a plurality of ECUs, that is, an EFI (Electronic Fuel Injection) ECU 01 that controls the internal combustion engine 1 , a generator ECU 02 that controls the power generation motor generator 2 and the generator inverter 21 , and a BMS (Battery Management) that controls the power storage device 3 . System) ECU 03, a driving machine ECU 04 that controls the traveling motor generator 4 and the driving machine inverter 41, etc., and a HV (Hybrid Vehicle) ECU that is a high-level controller that supervises the control thereof, are connected to a CAN (Controller Area Network), etc. are connected so as to be able to communicate with each other via an electric communication line.

For the ECU 0, a vehicle speed signal a output from a vehicle speed sensor that detects the actual vehicle speed, a crank angle signal b output from a crank angle sensor that detects the rotation angle of the crankshaft of the internal combustion engine 1 and the engine speed , the accelerator opening signal c output from a sensor that detects the amount of depression of the accelerator pedal by the driver as the accelerator opening (in other words, the driving force requested by the driver to the vehicle), and the driver pressing the brake pedal. A brake depression amount signal output from a switch that detects depression, a sensor that detects the amount of depression of the brake pedal by the driver, or a sensor that detects master cylinder pressure, which is the pressure of the brake fluid discharged from the master cylinder 16. d, an intake air temperature/pressure signal output from a temperature/pressure sensor that detects the intake air temperature and pressure in the intake passage 13 (especially the surge tank 133), and a water temperature that detects the temperature of the cooling water of the internal combustion engine 1 A cooling water temperature signal f output from a sensor, and a battery output from a sensor (particularly, a battery current and/or battery voltage sensor) that detects the amount of charge stored in the power storage device 3 (or SOC (State Of Charge)) A signal g, a negative pressure signal h output from a negative pressure sensor for detecting the negative pressure stored in the constant pressure chamber of the brake booster 15, and the like are input.

The ECU 0 senses through various sensors the accelerator opening degree operated by the driver, the shift position, that is, the position of the shift lever (selector lever), the ON/OFF state of the switch operated by the driver, and the current The traveling motor generator 4 is controlled according to the vehicle speed, the road gradient, the amount of charge stored in the power storage device 3, the magnitude of the negative pressure stored in the brake booster 15, the power generated by the power generating motor generator 2, and the like. increases or decreases the rotational driving force output by , the rotational driving force output by the internal combustion engine 1, and the electric power generated by the motor generator 2 for power generation.

In principle, if the power storage device 3 is currently storing a sufficient amount of electric charge and the required output of the traction motor generator 4 is small, the supply of fuel to the internal combustion engine 1 is cut off and the internal combustion engine 1 is operated. do not. On the other hand, if the amount of electric charge stored in the storage device 3 decreases, or if the output required for the motor generator 4 for traveling is large, the internal combustion engine 1 is started and fuel is supplied to the cylinders to supply fuel to the cylinders. Firing for combustion is executed, and the rotational driving force output from the internal combustion engine 1 drives the generator motor generator 2 to generate power to charge the power storage device 3 or increase the electric power supplied to the motor generator 4 for running. do.

The internal combustion engine 1 is started while the fuel is not being supplied to the cylinders of the internal combustion engine 1 and the internal combustion engine 1 is not being operated, and the drive wheels 62 are being driven by the traveling motor generator 4 to drive the vehicle. In order to execute power generation by the motor generator 2 for power generation, first, the motor generator 2 for power generation is operated as an electric motor, thereby performing motoring for starting the internal combustion engine 1 . Then, the crankshaft of the internal combustion engine 1 rotates a predetermined number of times or more or a predetermined angle or more, and after completion of cylinder discrimination for obtaining the current stroke or piston position of each cylinder of the internal combustion engine 1, each cylinder of the internal combustion engine 1 rotates. To inject fuel at an appropriate timing in accordance with a stroke, and to start firing for igniting and burning the fuel at an appropriate timing. The rotation angle and rotation speed of the crankshaft of the internal combustion engine 1, i.e., the engine speed, can be detected (in the generator ECU 02) via a resolver attached to the motor generator 2 for power generation. It can also be detected via a sensor (at EFI ECU01).

When the internal combustion engine 1 rotates independently and can output the rotational driving force necessary for power generation, in other words, even if the output of the motor generator 2 for power generation is reduced, the engine speed does not tend to increase. When it can be maintained, the output of the motor generator 2 for power generation, which is operated as an electric motor, is reduced to 0 to end the motoring, and the motor generator 2 for power generation is rotationally driven by the internal combustion engine 1 this time. Furthermore, the power generation motor generator 2 is operated as a power generator, and the generated power is increased from zero.

Thus, the intake air amount and the fuel injection amount supplied to the cylinder 1 of the internal combustion engine 1 and the electric power generated by the motor generator 2 are adjusted to increase or decrease so that the engine speed follows the target speed, which is increased in stages. Implement feedback control. The final target engine speed is the engine speed at which the internal combustion engine 1 can be operated at optimum or near-optimal efficiency and which is most advantageous for the fuel consumption rate, or at which the internal combustion engine 1 produces maximum torque or maximum output or torque or output close thereto. Set the rpm that you can achieve.

An EFI ECU 01 forming a part of the ECU 0 acquires various types of information a, b, c, d, e, f, g, and h necessary for controlling the operation of the internal combustion engine 1 through an input interface, and calculates the engine speed. is obtained, and the amount of air taken into the cylinder 11 is estimated. Then, the required fuel injection amount (necessary to achieve the target air-fuel ratio) matching the intake air amount, fuel injection timing (including the number of fuel injections for one combustion), fuel injection pressure, ignition timing (one time It determines operating parameters of the internal combustion engine 1 such as the number of ignitions for combustion), the required EGR rate (or EGR gas amount), and the like. The EFI ECU 01 outputs various control signals i, j, k, l corresponding to operating parameters to the igniter of the spark plug 112, the injector 111, the throttle valve 132, the EGR valve 123, etc. via an output interface.

3 and 4 show an example of the procedure of processing executed by the ECU 0 according to the program in this embodiment. The ECU 0 obtains the output currently requested for the driving motor generator 4 based on the current accelerator pedal position operated by the driver and the current vehicle speed (step S1). The driving force to be applied from the running motor generator 4 to the drive wheels 62 increases as the accelerator opening increases. The required output of the traveling motor generator 4 increases as the driving force to be applied to the drive wheels 62 increases, and increases as the vehicle speed increases.

Next, the amount of electric power to be supplied to the motor generator 2 for motoring the internal combustion engine 1 is added to the amount of electric power to be supplied to the motor generator 4 for traveling in order to achieve the above required output. , the current required power is obtained (step S2). If the internal combustion engine 1 is currently being motored, the electric power actually consumed by the electric power generation motor generator 2 that executes the motoring is the electric power to be supplied to the electric power generation motor generator 2 . If the internal combustion engine 1 is not currently being motored or fired, and the rotation of the internal combustion engine 1 is stopped, the power generation motor generator 2 will be activated when the internal combustion engine 1 needs to be motored later. The electric power to be input, that is, the reserve electric power that is reserved without being supplied to the motor generator 4 for traveling, is the electric power to be supplied to the motor generator 2 for power generation. If the internal combustion engine 1 is already firing, the electric power to be supplied to the motor generator 2 is zero.

Then, if the rotation of the internal combustion engine 1 is currently stopped (step S3) and the electric power that can be output by the power storage device 3 at present is equal to or less than the above-described required electric power (step S4), then the vehicle is accelerated. This means that the electric power consumed by the traveling motor generator 4 cannot be covered by the power storage device 3 alone. Therefore, after starting the internal combustion engine 1 and shifting from motoring to firing (step S5), the motor-generator 2 for power generation is operated as a generator to generate electric power, and the generated electric power is supplied to the motor-generator 4 for running. do.

On the other hand, if the power that can be output by the power storage device 3 exceeds the required power (step S4), the power consumed by the traction motor generator 4 can be covered by the power storage device 3 alone. There is no need to generate power by the motor generator 2 for Therefore, the internal combustion engine 1 is kept stopped without being started (step S6).

If the internal combustion engine 1 is currently rotating due to motoring or firing (step S3) and the current output power of the power storage device 3 is equal to or less than the required power (step S7), the internal combustion engine 1 is After switching from ring to firing, or continuing the firing of the internal combustion engine 1 (step S8), the electric power generation motor generator 2 generates electric power, and the generated electric power is supplied to the traveling motor generator 4.

On the other hand, if the electric power that can be output by the power storage device 3 exceeds the required electric power (step S7), the motoring, firing, or rotation of the internal combustion engine 1 is stopped through steps S9 to S20 described below. Choose one.

First, if the current driving mode selected by the driver by manipulating the shift lever or switch is a mode that emphasizes fuel efficiency over vehicle driving performance (step S9), the internal combustion engine 1 to stop the rotation of the internal combustion engine 1 (step S10), thereby suppressing unnecessary power consumption by the power generation motor generator 2 and unnecessary fuel consumption by the internal combustion engine 1. do. Here, the mode that emphasizes driving performance is a mode that is selected when the driver desires sporty driving with higher acceleration, such as the so-called S range of the shift position or power mode. be. On the other hand, the mode in which the fuel consumption performance is more emphasized includes the D range (non-S range) of the shift position, the eco mode (non-power mode), and the like.

Also, when the current vehicle speed is lower than a predetermined value (eg, 60 km/h) (step S11), the rotation of the internal combustion engine 1 is stopped (step S12). When the vehicle speed is low, the rotation speed of the traveling motor generator 4 connected to the driving wheels 62 is also low. If the output of the running motor generator 4 is the same, the lower the rotation speed, the greater the driving force, and the more the acceleration of the vehicle. As a result, the initial acceleration is ensured when the driver depresses the accelerator pedal again, so that the internal combustion engine 1 is allowed to stop without maintaining motoring or firing. In addition, there is also the implication of maintaining high NVH (Noise, Vibration and Harshness) performance of the vehicle. The running noise of the vehicle masks the noise generated by the internal combustion engine 1 and the power generation motor generator 2 . When the vehicle speed decreases, the noise masked by the running noise is exposed to the extent that the running noise is reduced, and is perceived by the passengers of the vehicle including the driver, increasing the possibility of causing discomfort and discomfort. Therefore, the internal combustion engine 1 and the electric power generation motor generator 2 are stopped to suppress the noise caused by them.

The driver has selected a mode that emphasizes the running performance of the vehicle (step S9), the current vehicle speed is higher than a predetermined value (step S11), and the running motor-generator 4 is supplied with power from the power storage device 3. operates as an electric motor to rotationally drive the drive wheels 62 (step S13), if the amount of charge currently stored in the power storage device 3 is equal to or greater than the threshold value (step S14), the power storage device 3, and therefore the internal combustion engine 1 is fired, but the internal combustion engine 1 is set to idling or a low-load operation close to idling (step S15). In the step S15, the power generation motor generator 2 is caused to generate little or no power. A substantially unloaded state. The reason why the internal combustion engine 1 is fired and kept rotating even though it is not generating power at this time is that when the driver strongly depresses the accelerator pedal and requests further acceleration of the vehicle later, the internal combustion engine 1 can be The intention is to increase the output of the engine 1 to start power generation, and to supply the necessary and sufficient amount of electric power to the motor generator 4 for traveling.

On the other hand, if the amount of charge currently stored in the power storage device 3 is below the threshold value (step S14), the internal combustion engine 1 is fired (step S16), and the power generation motor generator 2 is operated as a power generator. , the electric power generated by the electric power generation motor generator 2 is mainly input to the power storage device 3 to charge the power storage device 3 . The engine load factor in step S16 becomes higher than the engine load factor in step S15. Naturally, the intake air amount and the fuel injection amount with which the cylinder 11 of the internal combustion engine 1 is charged in step S16 are increased from those in step S15. Later, when the driver depresses the accelerator pedal to request acceleration, the output of the internal combustion engine 1 and the power generation amount of the motor generator 2 are further increased, and the corresponding amount of electric power is supplied to the motor generator 4 for traveling. Become.

The driver has selected a mode that emphasizes the running performance of the vehicle (step S9), the current vehicle speed is higher than a predetermined value (step S11), and the running motor generator 4 is being rotated by the driving wheels 62. When the vehicle is rotating, that is, when the driving motor generator 4 is not generating a driving force as an electric motor (step S13), if the amount of electric charge currently stored in the power storage device 3 is equal to or greater than the threshold value (step S17). Therefore, the internal combustion engine 1 is shifted from firing to motoring, or the motoring of the internal combustion engine 1 is continued (step S19). At this time, the electric power regenerated by the motor-generator 4 for traveling is input to the motor-generator 2 for power generation, which mainly performs motoring. The reason why the rotation of the internal combustion engine 1 is maintained is that when the driver strongly depresses the accelerator pedal and requests further acceleration of the vehicle later, the internal combustion engine 1 is restarted as quickly as possible to start generating power. It is intended to be prepared so as to be able to supply a necessary and sufficient amount of electric power to the motor generator 4 for traveling. The threshold value with which the power storage amount of the power storage device 3 is compared in step S17 may be a different value from the threshold value with which the power storage amount of the power storage device 3 is compared in step S14, or may be the same value.

However, if there is a concern that the purification efficiency of the harmful substances by the catalyst 141 attached to the exhaust passage 14 of the internal combustion engine 1 will be lowered (step S18), the internal combustion engine 1 is restarted and fired while the internal combustion The engine 1 is put into idling or low-load operation close to idling (step S20). During motoring (step S19) in which the internal combustion engine 1 is rotationally driven by the motor generator 2 for power generation, fuel injection and combustion are not performed in the internal combustion engine 1, and normal temperature air containing no combustion gas is supplied to the intake passage 13 and the cylinders 11. and blows through the exhaust passage 14 . When the air flows through the catalyst 141, the temperature of the catalyst 141 drops, and an excessive amount of oxygen is stored in the catalyst 141, reducing the efficiency of oxidation/reduction of the harmful substances HC, CO and NOx by the catalyst 141. do. Therefore, after the motoring of the internal combustion engine 1 continues for a certain amount of time or longer, the internal combustion engine 1 is intentionally fired to allow the high-temperature combustion gas to flow into the catalyst 141 to promote the temperature rise of the catalyst 14 and to increase the temperature of the catalyst 14. reduces the amount of oxygen stored in This is beneficial to prevent deterioration of vehicle emissions. In step S18, for example, the temperature of the catalyst 14 detected via a sensor has dropped below a predetermined value, the cooling water temperature or the lubricating oil temperature of the internal combustion engine 1 has dropped below a predetermined value, or the motoring of the internal combustion engine 1 (step A certain amount of time or more has passed since the start of S19), a certain amount or more of air has flowed since the start of motoring, or the internal combustion engine 1 or the power generation motor generator 2 has remained constant since the start of motoring. Under the condition that the catalyst 141 has rotated more than the number of times, it is determined that there is a concern that the purification efficiency of the harmful substances by the catalyst 141 may be lowered, and the process proceeds to firing in step S20.

On the other hand, if the amount of electric charge currently stored in the power storage device 3 is below the threshold value (step S17), instead of motoring that consumes power, the internal combustion engine 1 is idling while firing. A low-load operation close to running or idling is performed (step S20). At this time, the electric power regenerated by the traveling motor generator 4 is mainly input to the power storage device 3 to charge the power storage device 3 . To reiterate, the reason why the rotation of the internal combustion engine 1 is maintained is to increase the output of the internal combustion engine 1 as quickly as possible when the driver strongly depresses the accelerator pedal and requests further acceleration of the vehicle later. It is intended to be prepared so that power generation can be started at the same time as the motor generator 4 for running, and a necessary and sufficient amount of electric power can be supplied to the motor generator 4 for traveling.

FIG. 5 shows an example of the control executed by the ECU 0 of this embodiment. In FIG. 5, the solid line indicates the running motor generator 4 and the power generating motor generator when the internal combustion engine 1 is already rotating by motoring or firing at time t0 when the driver depresses the accelerator pedal to request acceleration. 2 shows the transition of the output. The one-dot chain line indicates transition of the outputs of the motor generator 4 for traveling and the motor generator 2 for power generation when the internal combustion engine 1 stops rotating at the same time t0 and the internal combustion engine 1 is started from now. In the latter case, it is necessary to rotate the internal combustion engine 1 by the power generating motor generator 2 until time t3 when the start of the internal combustion engine 1 is completed. As a result, the electric power that can be supplied from the power storage device 3 to the traveling motor generator 4 is reduced. After that, power can be supplied from both the electric power generation motor generator 2 and the power storage device 3 to the running motor generator 4, and the achievement of the required output corresponding to the accelerator opening is delayed until time t4. As described above, the rise of the driving force applied from the traveling motor generator 4 to the driving wheels 62 is delayed, and the acceleration of the vehicle is delayed.

On the other hand, in the former case, power generation by the power generation motor generator 2 can be started at an earlier time point t1, and electric power from both the power generation motor generator 2 and the power storage device 3 can be supplied to the driving motor generator 4. becomes. Therefore, at time t2, which is several tenths of a second earlier than time t4, the required output corresponding to the degree of opening of the accelerator can be achieved. In this way, the driving force applied to the driving wheels 62 from the traveling motor generator 4 is rapidly increased, and the vehicle is accelerated as desired by the driver.

In the present embodiment, the driving motor 4 that can supply driving force for driving to the drive wheels 62, and the internal combustion engine that can supply the driving force for power generation to the generator 2 that generates electric power to be supplied to the driving motor 4 A control device 0 for controlling a hybrid vehicle including an engine 1 and a motoring electric motor 2 capable of supplying a driving force for rotating the internal combustion engine 1 to the internal combustion engine 1, wherein the traveling electric motor 4 is a drive wheel. 62 for powering, and the power that can be output by the vehicle-mounted power storage device 3 exceeds the power consumed by the traction motor 4 for powering. If it is greater than or equal to the threshold value, the internal combustion engine 1 is set to the idling state or the low-load operation state close to idling while the internal combustion engine 1 is being fired so that the generator 2 generates little or no power (step S15), and if the value is less than the threshold value. A control device 0 for a hybrid vehicle is configured to fire the internal combustion engine 1, cause the generator 2 to generate electricity, and charge at least part of the generated electricity to the storage device 3 (step S16).

In addition, in the present embodiment, the driving force for power generation is supplied to the driving motor 4 capable of supplying the driving force for driving to the drive wheels 62 and to the generator 2 for generating the electric power to be supplied to the driving motor 4. and a motoring electric motor 2 capable of supplying the internal combustion engine 1 with driving force for rotating the internal combustion engine 1, wherein the driving electric motor 4 is In a situation where regenerative power is being generated by being rotated by the drive wheels 62, if the charge amount stored in the vehicle-mounted power storage device 3 is equal to or greater than the threshold value, the internal combustion engine 1 is motored by the motoring electric motor 2 (step S19), if the value is less than the threshold value, fire the internal combustion engine 1, set it to an idling state or a low-load operation state close to idling, and charge the power storage device 3 with at least part of the regeneratively generated electric power ( Step S20) A control device 0 for a hybrid vehicle that executes control is constructed.

According to this embodiment, when the driver depresses the accelerator pedal and the required output of the traction motor 4 increases, power generation by the generator 2 is started as soon as possible, and the generated electric power is supplied to the traction motor. 4 can be supplied. Then, the traveling electric motor 4 can generate necessary and sufficient driving force, and the driving force can be input to the driving wheels 62 . As a result, acceleration of the vehicle without delay can be realized. In particular, when the driver requests further acceleration of the vehicle in a state where the vehicle speed is already higher than a certain level and the rotation speed of the traveling electric motor 4 is high, the acceleration that matches the driver's intention can be achieved.

This embodiment is intended to exhibit necessary and sufficient power performance when the capacity and output of the power storage device 3 mounted on the vehicle are originally small, or when the amount of electric charge currently stored in the power storage device 3 is small. effective. This is useful in a small vehicle that lacks space for mounting a large-sized, large-capacity power storage device 3 . It is also advantageous for avoiding the increase in weight and cost associated with mounting the large-sized, large-capacity power storage device 3 .

The present invention is not limited to the embodiments detailed above. The specific configuration and processing contents of each section can be modified in various ways without departing from the gist of the present invention.

INDUSTRIAL APPLICABILITY The present invention can be applied to the control of hybrid vehicles.

0... Control unit (ECU)
DESCRIPTION OF SYMBOLS 1... Internal combustion engine 2... Generator, electric motor for motoring (motor generator for power generation)
3 power storage device 4 traveling motor (traveling motor generator)
62... Drive wheel

Claims (3)

a traveling electric motor capable of supplying a driving force for traveling to the driving wheels;
an internal combustion engine capable of supplying driving force for power generation to a generator that generates electric power to be supplied to the traction motor;
A control device for controlling a hybrid vehicle including a motoring electric motor capable of supplying an internal combustion engine with driving force for rotating the internal combustion engine,
In a situation where the traction motor is driven by the drive wheels to generate regenerative power, if the amount of electric charge stored in the on-vehicle power storage device is equal to or greater than the threshold, the internal combustion engine is motored by the motoring motor and the threshold is reached. If it is less than , the internal combustion engine is fired while the hybrid vehicle is placed in an idle operation or a low-load operation state close to idle operation, and control is performed to charge the power storage device with at least part of the regeneratively generated electric power. Control device. Motoring occurs when the traction motor drives the drive wheels for power running, and the electric power that can be output by the in-vehicle power storage device becomes the power consumed by the traction motor for powering. If the amount of electric charge stored in the power storage device is greater than or equal to the threshold under the condition that the electric power to be input to the electric motor is exceeded, the internal combustion engine is fired while idling or idling. a low-load operating state close to , causing the generator to generate little or no power, and if the threshold is below the threshold, fire the internal combustion engine to cause the generator to generate power, and charge at least a portion of the generated power to the power storage device. 2. The hybrid vehicle control device according to claim 1, wherein the control is executed. Motoring occurs when the traction motor drives the drive wheels for power running, and the electric power that can be output by the in-vehicle power storage device becomes the power consumed by the traction motor for powering. The current driving mode selected by the driver is a mode that emphasizes fuel consumption performance over vehicle driving performance under circumstances where the electric power that will be input to the vehicle motor exceeds that taken into consideration. If the current vehicle speed is below a predetermined value, the internal combustion engine is stopped. 3. A control system for a hybrid vehicle according to claim 1 or 2, wherein the internal combustion engine fires if the value is higher than the value.

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