JP2021054109A - Control device of hybrid vehicle - Google Patents

Abstract

To suppress an internal combustion engine from being started up at a timing when a driver steps on a brake pedal in a hybrid vehicle.SOLUTION: When the negative pressure stored in a brake booster attached to an internal combustion engine is less than a threshold under such a situation that a vehicle travels in such a state that the rotation of the internal combustion engine is stopped, a control device performs motoring for rotating the internal combustion engine with a motoring electric motor or firing for starting up the internal combustion engine to rotate by supplying fuel to the internal combustion engine. When a prescribed deceleration travel condition in which it is assumed that a driver has stepped on a brake pedal or is going to step on the brake pedal is satisfied, the control device lowers the threshold in comparison to a case where the condition is not satisfied or temporarily inhibits the motoring and firing.SELECTED DRAWING: Figure 5

Description

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

Recently, hybrid vehicles equipped with two types of power sources, an electric motor and an internal combustion engine, have seen a certain degree of widespread use. In series hybrid vehicles (see, for example, the patent documents below), an internal combustion engine drives a motor generator for power generation to generate electricity, and the generated power is used as a power storage device, that is, a lithium ion secondary battery or a nickel hydrogen secondary battery. It is stored in a battery and / or a capacitor such as, and is supplied to a traveling motor generator. Then, the drive wheels of the vehicle are rotated by the traveling motor generator to travel.

Not only the power generation motor generator but also the traveling motor generator can generate power by regenerative braking and store the generated power in the power storage device. When the 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 power generation motor generator, which is operated as an electric motor to rotate and drive the internal combustion engine. This consumes surplus power.

In a hybrid vehicle, the vehicle can be driven by the rotational driving force output by the traveling motor generator without the internal combustion engine burning the fuel to generate the rotational driving force. Therefore, even during the operation of the vehicle, the state in which 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 for the traction motor generator is large, the internal combustion engine is started, fuel is supplied to the cylinders and burned, and the rotary drive is output by the internal combustion engine. The power generation motor generator is driven by force to generate power to charge the power storage device or increase the power supplied to the traveling motor generator.

In a series hybrid vehicle, the power generation motor generator also serves to motor (or crank) the internal combustion engine in preparation for starting the stopped internal combustion engine. At the time of motoring, the necessary electric power is supplied from the power storage device.

Japanese Unexamined Patent Publication No. 2019-131035

Conventionally, for the purpose of reducing the operating force required when braking the vehicle, that is, the pedaling force of the brake pedal, the pedaling force is doubled by using the intake negative pressure generated on the downstream side of the throttle valve in the intake passage of the internal combustion engine. Vacuum booster type (vacuum type) brake boosters are widely used. When the negative pressure stored in the brake booster decreases, the internal combustion engine is motorized or fired to generate intake negative pressure, and the negative pressure is supplied to the brake booster.

The negative pressure stored in the brake booster is consumed when the driver of the vehicle depresses the brake pedal. As already mentioned, the hybrid vehicle can run with the rotation of the internal combustion engine stopped. While the rotation of the internal combustion engine is stopped, the intake negative pressure cannot be supplied to the brake booster.

Therefore, under the condition that the internal combustion engine is running with the rotation stopped, the motoring or firing of the internal combustion engine is started in order to replenish the negative pressure to the brake booster at the timing when the driver depresses the brake pedal. May be done. If the internal combustion engine is started at the timing when the driver depresses the brake pedal, there is a concern that the driver may feel uncomfortable due to the vibration and noise.

The same thing happens when charging an in-vehicle power storage device. When the amount of electric charge stored in the power storage device decreases, it becomes necessary to fire the internal combustion engine and drive the generator to generate electricity. However, the driver brakes the start timing of the internal combustion engine and the generator. It may coincide with the timing of pedaling.

The present invention has been made by paying attention to the above problems for the first time, and is intended to suppress the start of the internal combustion engine at the timing when the driver depresses the brake pedal.

In the present invention, a traveling electric motor capable of supplying a driving force for traveling to a driving wheel and a generator capable of supplying a driving force for generating power to be supplied to the traveling electric motor can be supplied with a driving force for power generation, or the driving wheels are driven. To the internal combustion engine that can supply the driving force for the internal combustion engine, the brake booster that stores the negative intake pressure generated downstream of the throttle valve in the intake passage of the internal combustion engine and uses the negative pressure to boost the brake pedal force, and the internal combustion engine. A control device that controls a hybrid vehicle equipped with a motoring electric motor capable of supplying a driving force for rotating the internal combustion engine, and brakes when the internal combustion engine is running in a stopped rotation state. When the negative pressure stored in the booster falls below the threshold value, the motoring that rotates the internal combustion engine by the motoring motor or the firing that supplies fuel to the internal combustion engine to start and rotate it. When the predetermined deceleration running condition that the driver is expected to step on or step on the brake pedal is satisfied, the threshold value is further lowered as compared with the case where it is not, or motoring and firing are temporarily performed. A control device for a hybrid vehicle that prohibits

Further, in the present invention, a traveling electric motor capable of supplying a driving force for traveling to the driving wheels, an internal combustion engine capable of supplying a driving force for power generation to a generator for generating power to be supplied to the traveling electric motor, and an internal combustion engine. A control device that controls a hybrid vehicle equipped with a motoring electric motor capable of supplying a driving force for rotating the internal combustion engine to the internal combustion engine, and is running in a state where the rotation of the internal combustion engine is stopped. When the amount of charge stored in the in-vehicle power storage device falls below the threshold value, fuel is supplied to the internal combustion engine to start and rotate the internal combustion engine, and the driver depresses the brake pedal. Alternatively, when a predetermined deceleration running condition that is expected to be stepped on is satisfied, the threshold value is further lowered as compared with the case where it is not satisfied, or a control device for a hybrid vehicle that temporarily prohibits firing is configured. ..

According to the present invention, in a hybrid vehicle, it is possible to prevent the internal combustion engine from starting when the driver depresses the brake pedal.

The figure which shows the schematic structure of the hybrid vehicle and the control device of the series type in one Embodiment of this invention. The figure which shows the outline of the internal combustion engine mounted on the hybrid vehicle of the same embodiment. The figure which shows the classification of the request output in the control performed by the control device of the same embodiment. The flow chart which shows the procedure example of the process which the control device of the same embodiment executes according to a program. The flow chart which shows the procedure example of the process which the control device of the same embodiment executes according to a program. The timing diagram which shows the relationship between the brake booster negative pressure and the start / stop of an internal combustion engine in the control carried out by the control device of the same embodiment.

An embodiment of the present invention will be described with reference to the drawings. FIG. 1 shows a schematic configuration of a main system of a hybrid vehicle according to the present embodiment. This hybrid vehicle includes an internal combustion engine 1, a power generation motor generator 2 driven by the internal combustion engine 1 to generate electricity, a power storage device 3 for storing the electric power generated by the power generation motor generator 2, a power generation motor generator 2 and /. Alternatively, it includes a traveling motor generator 4 that drives the drive wheels 62 of the vehicle by receiving power from the power storage device 3.

The hybrid vehicle of the present embodiment is a series hybrid type electric vehicle that uses the internal combustion engine 1 only for power generation, and the driving force for traveling is supplied exclusively to the driving wheels 62 of the vehicle from the traveling motor generator 4. The internal combustion engine 1 and the drive wheels 62 are mechanically separated from each other, and the rotational driving force is not originally transmitted between the two. That is, the internal combustion engine 1 can rotate completely independently of the traveling motor generator 4 and the drive wheels 62, and can stop completely independently. Therefore, the power storage device 3 is sufficient even when the vehicle can be driven by the driver depressing the accelerator pedal during operation of the vehicle in which the ignition switch (power switch or ignition key) is operated to be ON. Under the condition that the charge is stored and the brake booster 15 stores a sufficient negative pressure, the operation of the internal combustion engine 1 accompanied by the combustion of fuel may not be performed.

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

The traveling motor generator 4 generates a driving force for traveling the vehicle, and inputs the driving force to the drive wheels 62 via the speed reducer 61. Further, the traveling motor generator 4 is rotated by being rotated by the drive wheels 62 to generate electricity, 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.

However, if the charge has already been stored up to the capacity of the power storage device 3 and it is difficult to charge the battery any more, the power generated by the traveling motor generator 4 is intentionally supplied to the power generation motor generator 2 to generate electricity. The motor generator 2 is operated as an electric motor to rotationally drive the internal combustion engine 1. As a result, the surplus electric power is exhausted while maintaining the braking performance of the vehicle. Further, at this time, since the rotation of the internal combustion engine 1 is maintained, it is possible to execute the fuel cut that temporarily stops the fuel supply to the cylinder of the internal combustion engine 1.

The 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 the power storage device 3 or the drive unit inverter 41. Further, when the generator inverter 21 operates the power generation motor generator 2 as an electric motor, the power generation motor generator 2 converts the DC power supplied from the power storage device 3 and / or the drive inverter 41 into AC power. Enter in.

The drive machine inverter 41 converts the DC power supplied from the power storage device 3 and / or the generator inverter 21 into AC power, and then inputs the DC power to the traveling motor generator 4. Further, the drive inverter 41 converts the AC power generated by the traveling motor generator 4 into DC power when the vehicle is regeneratively braked, and then inputs the AC power to the power storage device 3 or the generator inverter 21. The generator inverter 21 and the drive inverter 41 form a part of the 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 having a high energy density, such as a lithium ion secondary battery or a nickel-hydrogen secondary battery. The power storage device 3 charges and stores the electric power generated by each of the power generation motor generator 2 and the traveling motor generator 4. Further, the power storage device 3 discharges electric power for operating each of the power generation motor generator 2 and the traveling motor generator 4 as an electric motor, and supplies the electric power required for the motor generators 2 and 4.

FIG. 2 shows an outline of the internal combustion engine 1 mounted on the hybrid vehicle of the present embodiment. The internal combustion engine 1 is a spark-ignition type 4-stroke engine, and includes a plurality of cylinders 11 (for example, three cylinders, one of which is shown in FIG. 1). An injector 111 for injecting fuel toward the intake port is provided in the vicinity of the intake port of each cylinder 11. Further, a spark plug 112 is attached to the ceiling of the combustion chamber of each cylinder 11. The spark plug 112 receives an induction voltage generated by the ignition coil to induce a spark discharge between the center electrode and the ground electrode.

The 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 from the upstream on the intake passage 13. 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 intake port is opened in front of the vehicle in order to take in cold air and improve the filling efficiency of the internal combustion engine.

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

The external EGR (Exhaust Gas Recirculation) device 12 realizes a so-called high-pressure loop EGR. The EGR device 12 includes an external EGR passage 121 that connects 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 an EGR passage 121. The EGR valve 123 that opens and closes and controls the flow rate of the EGR gas flowing through the EGR passage 121 is used as an element. The inlet of the EGR passage 121 is connected to the exhaust manifold 142 in the exhaust passage 14 or a predetermined position downstream thereof. The outlet of the EGR passage 121 is connected to a predetermined position downstream of the throttle valve 132 in the intake passage 13, specifically, the surge tank 133.

The internal combustion engine 1 is provided with a brake booster 15 for reducing the operating force required when braking the vehicle, that is, the pedaling force of the brake pedal. In this field, the brake booster 15 draws in intake negative pressure from a portion (or surge tank 133) on the downstream side of the throttle valve 132 in the intake passage 13, and uses the negative pressure to boost the pedaling force of the brake pedal. It is widely known. The brake booster 15 has a constant pressure chamber (negative pressure chamber) for storing negative pressure and a transformer chamber (atmospheric pressure chamber) to which atmospheric pressure is applied, and the constant pressure chamber is connected to an intake passage 13 via a negative pressure pipeline 151. ing. The negative pressure pipeline 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 conduit 151 to keep the negative pressure in the constant pressure chamber and prevent the positive pressure from being applied to the constant pressure chamber.

When the brake pedal is not operated by the driver, the constant pressure chamber and the transformer chamber communicate with each other, and the transformer chamber is isolated from the atmospheric pressure. When the brake pedal is operated, the space between the constant pressure chamber and the transformer chamber is cut off, and the atmosphere is introduced into the transformer chamber. As a result, the pressure difference between the constant pressure chamber and the transformer chamber becomes the control pressure that doubles the pedaling force of the brake pedal. The brake pedal 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 pressure circuit, and the brake device brakes the vehicle. Used.

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

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

Then, the ECU 0 is sensed via various sensors, such as the accelerator opening operated by the driver, the shift position, that is, the position of the shift lever or the selector lever, the current vehicle speed, the road surface gradient, and the power storage device 3. The rotational driving force output by the traveling motor generator 4 and the output by the internal combustion engine 1 according to the amount of stored charge, the magnitude of the negative pressure stored in the brake booster 15, the generated power of the power generation motor generator 2, and the like. The rotational driving force to be generated and the magnitude of the electric power generated by the power generation motor generator 2 are controlled to increase or decrease.

As a general rule, if the power storage device 3 currently stores sufficient electric charge and the output required for the traveling 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 charge stored in the power storage device 3 is below the threshold value or the output required for the traveling motor generator 4 is large, the internal combustion engine 1 is started to supply fuel to the cylinder. Is executed, the generator motor generator 2 is driven by the rotational driving force output from the internal combustion engine 1, the power generation is performed to charge the power storage device 3, or the electric power to be supplied to the traveling motor generator 4. To enhance.

FIG. 3 shows the relationship between the output required by the driver of the vehicle and the necessity of operating the internal combustion engine 1 and the power generation motor generator 2. The required output is determined by the accelerator opening and the vehicle speed operated by the driver. The driving force to be applied to the driving wheels 62 increases as the accelerator opening increases. The required output increases as the driving force to be applied to the drive wheels 62 increases, and increases as the vehicle speed increases. In FIG. 3, the required output becomes larger toward the upper right.

In the low output region I where the driving force to be applied to the drive wheels 62 is relatively small and the vehicle speed is relatively low, the ECU 0 stops its operation without supplying fuel to the internal combustion engine 1 and generates a power generation motor generator 2. Do not operate as a machine. In the low output region I, the traveling motor generator 4 receives electric power only from the power storage device 3 and outputs a driving force for traveling the vehicle. The low output region I is typically when the accelerator opening is 0 or smaller than a predetermined value, or the vehicle is decelerating.

On the other hand, the ECU 0 supplies fuel to the internal combustion engine 1 and operates it in the medium and high output regions II and III in which the driving force to be applied to the drive wheels 62 is larger than a certain level or the vehicle speed is higher than a certain level, and the power generation motor is operated. The generator 2 is operated as a generator. In the medium output region II where the required output is not remarkably large, the traveling motor generator 4 mainly receives electric power from the power generation motor generator 2 and outputs the driving force for traveling the vehicle. At this time, a small amount of power is supplied from the power storage device 3, or no power is supplied from the power storage device 3. In the high output region III in which the required output is remarkably large, the traveling motor generator 4 receives electric power from both the power generation motor generator 2 and the power storage device 3 and outputs the driving force for traveling the vehicle.

The internal combustion engine 1 is started while the drive wheels 62 are driven by the traveling motor generator 4 to drive the vehicle without supplying fuel to the cylinders of the internal combustion engine 1 to operate the internal combustion engine 1. In order to execute power generation by the power generation motor generator 2, first, the power generation motor generator 2 is operated as an electric motor, whereby motoring for starting the internal combustion engine 1 is performed. Then, after the crankshaft of the internal combustion engine 1 rotates a predetermined number of times or more or a predetermined angle or more, and the cylinder determination for knowing the current stroke of each cylinder of the internal combustion engine 1 or the position of the piston is completed, the cylinder of the internal combustion engine 1 Inject fuel at an appropriate timing according to the process, and start firing to ignite and burn the fuel at an appropriate timing. The rotation angle and rotation speed of the crankshaft of the internal combustion engine 1, that is, the engine speed can be detected via the resolver attached to the motor generator 2 for power generation (in the generator ECU 02), and the crank angle attached to the internal combustion engine 1 It can also be detected via a sensor (in the EFI ECU 01).

The internal combustion engine 1 rotates autonomously and is in a state where it can output the rotational driving force required for power generation. In other words, even if the output of the power generation motor generator 2 is reduced, the engine speed still tends to increase. When it becomes possible to maintain it, the output of the power generation motor generator 2 operating as an electric motor is reduced to 0 to end the motoring, and this time, the power generation motor generator 2 is rotationally driven by the internal combustion engine 1. Further, the power generation motor generator 2 is operated as a generator, and the generated power is increased from 0.

Then, the intake amount and fuel injection amount supplied to the cylinder 1 of the internal combustion engine 1 and the generated power of the power generation motor generator 2 are adjusted in an increase or decrease so as to follow the target rotation speed in which the engine speed is gradually increased. Implement feedback control. The final target rotation speed is the rotation speed at which the internal combustion engine 1 can be operated with optimum or near optimum efficiency and is most advantageous for the fuel consumption rate, or the internal combustion engine 1 has the maximum torque or maximum output or a torque or output close to this. Set the number of revolutions so that it can be achieved.

Incidentally, the EFI ECU 01, which forms a part of the ECU 0, acquires various information a, b, c, d, e, f, g, h necessary for the operation control of the internal combustion engine 1 via the input interface, and obtains the engine rotation speed. And estimate the amount of air sucked into the cylinder 11. Then, the required fuel injection amount (necessary to realize the target air-fuel ratio), fuel injection timing (including the number of fuel injections per combustion), fuel injection pressure, and ignition timing (once) corresponding to the intake air amount. The operating parameters of the internal combustion engine 1 such as the required number of ignitions for combustion), the required EGR ratio (or the amount of EGR gas), and the like are determined. The EFI ECU 01 outputs various control signals i, j, k, l corresponding to the operation parameters to the igniter, injector 111, throttle valve 132, EGR valve 123, etc. of the spark plug 112 via the output interface.

However, as shown in FIG. 4, in the ECU 0, the negative pressure currently stored in the brake booster 15 sets a threshold value under the condition that the vehicle is running with the rotation of the internal combustion engine 1 stopped (step S1). When it falls below (step S2), regardless of the magnitude of the current required output, the motor generator 2 for power generation drives the crankshaft of the internal combustion engine 1 to rotate, or the internal combustion engine 1 is started to the cylinder 11. Firing is performed by supplying fuel to rotate the crankshaft autonomously (step S3). When the crankshaft of the internal combustion engine 1 is rotated to move the piston and the intake / exhaust valve of each cylinder 1, the intake air flows in the intake passage 13, and the intake negative pressure is generated downstream of the throttle valve 132 which is the intake throttle valve. When it is generated, the negative pressure can be replenished in the constant pressure chamber of the brake booster 15.

Then, as shown in FIG. 5, the EUC0 of the present embodiment has a threshold value to be compared with the negative pressure stored in the brake booster 15 in step S2 when the driver actually steps on the brake pedal. Alternatively, when the predetermined deceleration running condition in which the brake pedal is expected to be depressed is satisfied (step S4), the threshold value is temporarily lowered as compared with the normal case (step S5). (Step S6). As a result, the possibility that the condition of step S2 becomes true is reduced, and the internal combustion engine 1 and the power generation motor generator 2 are suppressed from starting to rotate at the timing when the driver depresses the brake pedal.

The deceleration running condition referred to in step S4 is, for example, that the current vehicle speed is equal to or less than a predetermined value and the deceleration of the vehicle speed is equal to or greater than a predetermined value (this predetermined value may be 0 or a value close to 0). It is a deceleration run. When such a condition is satisfied, it is expected that the driver will soon step on the brake pedal to brake the vehicle.

FIG. 6 shows a pattern of control performed by ECU 0 of the present embodiment. The alternate long and short dash line in FIG. 6 represents a threshold value to be compared with the negative pressure stored in the brake booster 15 which the ECU 0 of the present embodiment raises and lowers as appropriate. The normal threshold value set in step S5 can be adjusted according to the current vehicle speed. For example, the higher the current vehicle speed, the longer the driver presses the brake pedal, and the more negative pressure is consumed by the brake booster 15, so it is conceivable to raise the threshold value. Assuming that the threshold value is not lowered below the normal value through steps S4 and S6, the negative pressure stored in the brake booster 15 is (normal) at _{the timing t 0 immediately after the driver depresses the brake pedal.} Below the threshold, there is a possibility that the motoring or firing of the internal combustion engine 1 will be started. Then, the driver feels the vibration and noise caused by the rotation of the internal combustion engine 1 and the power generation motor generator 2 immediately after he / she depresses the brake pedal. Such behavior causes the driver to feel a sense of discomfort due to the overlap between the stoppage and the start of the internal combustion engine 1.

But Lowering than normal threshold through steps S4 and S6, the timing t ₁ to the driver is delayed than the timing t ₀ immediately after stepping on the brake pedal, a negative pressure is first stored in the brake booster 15 ( Below the threshold (lowered than normal), the motoring or firing of the internal combustion engine 1 is started. Therefore, the discomfort given to the driver can be greatly reduced.

The threshold value temporarily lowered in step S6 is returned to the normal threshold value after the predetermined release condition is satisfied (step S7) (step S5). The release condition referred to in step S7 is, for example, that a certain time has passed since the driver stepped on the brake pedal, or that a certain time has passed since the vehicle speed became 0 or a predetermined value close to 0 and the vehicle stopped. That and so on.

In step S6, instead of lowering the threshold value to be compared with the negative pressure stored in the brake booster 15, the motoring and firing of the internal combustion engine 1 are temporarily prohibited, that is, stored in the brake booster 15. Even if the negative pressure falls below the (normal) threshold, motoring and firing may not be performed immediately. At this time, the ban on motoring or firing of the internal combustion engine 1 is lifted after the release condition of step S7 is satisfied.

Further, when the amount of electric charge currently stored in the power storage device 3 falls below the threshold value under the condition that the vehicle is running with the rotation of the internal combustion engine 1 stopped, the ECU 0 determines the current required output. Regardless of this, the internal combustion engine 1 is started, fuel is supplied to the cylinder 11, fire is performed to rotate the crankshaft, and the power generation motor generator 2 is driven to generate power and charge the power storage device 3.

Here, the threshold value to be compared with the amount of electric charge stored in the power storage device 3 is also the same as the threshold value to be compared with the negative pressure stored in the brake booster 15 when the driver depresses the brake pedal or the brake. When a predetermined deceleration running condition where the pedal is expected to be stepped on is satisfied, the brake can be temporarily lowered as compared with a normal case where the pedal is not depressed. The lowered threshold value is returned to the normal threshold value after the predetermined release condition is satisfied.

Alternatively, instead of lowering the threshold value, firing of the internal combustion engine 1 is temporarily prohibited, that is, even if the amount of electric charge stored in the power storage device 3 falls below the (normal) threshold value, firing is performed immediately. It may not be. At this time, the firing of the internal combustion engine 1 is lifted after the release condition is satisfied.

In the present embodiment, the traveling electric motor 4 capable of supplying the driving force for traveling to the drive wheels 62 and the internal combustion engine capable of supplying the driving force for power generation to the generator 2 for generating the electric motor to be supplied to the traveling electric motor 4. The engine 1, the brake booster 15 that stores the intake negative pressure generated downstream of the throttle valve 132 in the intake passage 13 of the internal combustion engine 1 and uses the negative pressure to double the brake pedal force, and the internal combustion engine 1 in the internal combustion engine 1. A control device 0 for controlling a hybrid vehicle including a motoring electric motor 2 capable of supplying a driving force for rotating 1, and running in a state where the rotation of the internal combustion engine 1 is stopped. When the negative pressure stored in the brake booster 15 falls below the threshold value, a motoring that rotates the internal combustion engine 1 by the motoring electric motor 2 or a firing that supplies fuel to the internal combustion engine 1 to start and rotate the internal combustion engine 1. When the predetermined deceleration running condition that the driver is expected to step on or step on the brake pedal is satisfied, the threshold value is lowered further or temporarily as compared with the case where the brake pedal is not depressed. A control device 0 for a hybrid vehicle that prohibits motoring and firing is configured.

Further, in the present embodiment, the traveling electric motor 4 capable of supplying the driving force for traveling to the drive wheels 62 and the generator 2 for generating the electric power to be supplied to the traveling electric motor 4 and the in-vehicle power storage device 3 are generated. A control device 0 for controlling a hybrid vehicle including an internal combustion engine 1 capable of supplying a driving force for the internal combustion engine 1 and a motoring electric motor 2 capable of supplying the internal combustion engine 1 with a driving force for rotating the internal combustion engine 1. When the amount of charge stored in the in-vehicle power storage device 3 falls below the threshold value while the internal combustion engine 1 is running in a stopped rotation state, fuel is supplied to the internal combustion engine 1 to start the internal combustion engine 1. When the predetermined deceleration running condition that the driver is expected to step on or step on the brake pedal is satisfied, the above threshold value is set higher than that in the case where the firing is performed. The control device 0 of the hybrid vehicle which is lowered or temporarily prohibits firing is configured.

According to the present embodiment, in the hybrid vehicle, it is possible to suppress the start-up of the internal combustion engine 1 at the timing when the driver depresses the brake pedal, and it is possible to greatly reduce the discomfort given to the driver.

The present invention is not limited to the embodiments described in detail above. For example, the vehicle in the above embodiment is a series hybrid vehicle, and it has not been considered that the driving force output by the internal combustion engine 1 is input to the drive wheels 62 instead of the generator 2.

However, the present invention can also be applied to hybrid vehicles of other types and hybrid vehicles in which the driving force output by the internal combustion engine is supplied to the drive wheels for the running of the vehicle. At this time, the driving force can be transmitted between the internal combustion engine and the driving wheels, and the internal combustion engine can rotate / stop independently of the driving wheels without transmitting the driving force between the two. A power transmission mechanism that can switch between states (a clutch that can switch between disconnection and disconnection, a transmission mechanism that uses planetary gears, etc.) is provided. Then, it is determined whether to operate or stop the internal combustion engine according to the required output corresponding to the accelerator opening, etc., and when the internal combustion engine is operated, the power transmission mechanism is set to the latter state and the internal combustion engine is motorized. Alternatively, fuel can be supplied to the cylinder to fire the internal combustion engine, and the driving force output by the internal combustion engine can be supplied to the drive wheels with the power transmission mechanism in the former state. Needless to say, when the operation of the internal combustion engine is stopped, the power transmission mechanism is put into the latter state.

In addition, the specific configuration of each part and the content of the process can be variously modified without departing from the spirit of the present invention.

The present invention can be applied to the control of a hybrid vehicle.

0 ... Control device (ECU)
1 ... Internal combustion engine 13 ... Intake passage 132 ... Throttle valve 15 ... Brake booster 2 ... Generator, motoring motor (motor generator for power generation)
3 ... Power storage device 4 ... Driving motor (driving motor generator)
62 ... Drive wheels

Claims (2)

A driving motor that can supply driving force to the driving wheels for driving,
An internal combustion engine that can supply the driving force for power generation to the generator that generates the electric power to be supplied to the traveling electric motor, or can supply the driving force for traveling to the driving wheels.
A brake booster that stores the intake negative pressure generated downstream of the throttle valve in the intake passage of the internal combustion engine and uses the negative pressure to boost the brake pedal force.
A control device for controlling a hybrid vehicle including a motoring electric motor capable of supplying a driving force for rotating the internal combustion engine to the internal combustion engine.
When the negative pressure stored in the brake booster falls below the threshold while the internal combustion engine is running with the rotation stopped, the motoring or internal combustion engine is fueled by the motoring motor. Is used for firing to start and rotate the fuel.
When the predetermined deceleration driving condition that the driver is expected to step on or step on the brake pedal is satisfied, the threshold value is further lowered as compared with the case where it is not, or motoring and firing are temporarily performed. Hybrid vehicle control device that prohibits. A driving motor that can supply driving force to the driving wheels for driving,
An internal combustion engine that can supply the driving force for power generation to the generator that generates the electric power that should be supplied to the traction motor.
A control device for controlling a hybrid vehicle including a motoring electric motor capable of supplying a driving force for rotating the internal combustion engine to the internal combustion engine.
When the amount of electric charge stored in the on-board power storage device falls below the threshold value while the internal combustion engine is running with the rotation stopped, a fire that supplies fuel to the internal combustion engine to start and rotate it. It is a ring
When the predetermined deceleration driving condition that the driver is expected to step on or step on the brake pedal is satisfied, the threshold value is lowered further or firing is temporarily prohibited as compared with the case where the brake pedal is not depressed. Hybrid vehicle control device.

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