JPH05328520A - Method for operating internal combustion engine for power generation of hybrid vehicle - Google Patents

Abstract

(57) [Abstract] [Purpose] It is possible to secure a battery charge amount for starting traveling of a hybrid vehicle having an electric motor for driving the vehicle and an internal combustion engine for power generation, and to increase the cruising range and power performance of the vehicle. To provide an engine driving method for a hybrid vehicle that can be achieved. [Structure] When it is determined that the battery charge amount is below a predetermined charge amount when the start key is operated and the vehicle stops operating (S51), an alarm lamp is lit to notify execution of engine operation. (S58), until the predetermined amount of stored electricity in the battery is reached (S51), or until a predetermined time elapses from the start of engine operation (S57), the engine is operated and the battery is reliably charged. However, when the engine stop switch is operated at the start of the engine operation or during the operation (S54), the engine operation is stopped (S52).

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a hybrid vehicle equipped with an electric motor for driving a vehicle and an internal combustion engine for power generation. The present invention relates to a method for operating a hybrid vehicle, which can increase the fuel consumption and the power performance of the vehicle.

[0002]

2. Description of the Related Art In recent years, due to environmental problems, regulations on exhaust gas emitted from vehicles driven by an internal combustion engine have become strict, and many new technologies have been researched and developed in order to meet the regulations. From the perspective of reducing the amount of exhaust gas,
It can be said that an electric vehicle that uses an electric motor as a drive source and emits no exhaust gas is ideal. However, a typical electric vehicle supplies electric power from a battery to an electric motor, and since the capacity of the battery that can be mounted on the vehicle is naturally limited, compared to a vehicle that uses an internal combustion engine as a drive source,
Poor power performance and short cruising range. In order to popularize electric vehicles, it is desired to solve such technical problems.

Therefore, as a measure for increasing the cruising distance of an electric vehicle, a hybrid type electric vehicle equipped with a generator driven by an internal combustion engine for charging a battery has recently been considered promising. In the hybrid vehicle, when the driver turns off the start key of the vehicle to stop the vehicle traveling, the power generation engine is stopped.

[0004]

Therefore, when the start key is turned off and the operation of the engine is stopped, the battery charging is forcibly terminated even when the engine is operating for battery charging. For this reason, insufficient charging of the battery is not resolved, and it may not be possible to restart the vehicle traveling.

Further, in the conventional hybrid vehicle, the engine is operated at a constant rotation speed in order to reduce the amount of exhaust gas from the internal combustion engine for power generation or to reduce the fuel consumption of the engine. The amount of electric power is substantially constant regardless of the driving state of the vehicle. Therefore, for example, during high load operation of a vehicle in which the electric power required by the electric motor for driving the vehicle increases, the required electric power may not be able to be covered by the amount of power generated by the generator, and the power shortage may be supplied from the battery. become. For this reason, the amount of electricity stored in the battery is reduced, the power performance of the vehicle is degraded, and the cruising range of the vehicle is likely to be shortened.

The present invention has been made to solve the above-mentioned problems, and is a hybrid that can secure the amount of battery charge for starting the running of the vehicle and can increase the cruising range of the vehicle and improve the power performance of the vehicle. The purpose is to provide a method of driving a car.

[0007]

In order to achieve the above object, the present invention provides a hybrid vehicle having an electric motor for driving the vehicle, which is supplied with electric power from a battery, and an internal combustion engine for power generation. The internal combustion engine for power generation is operated when the amount of stored electricity in the battery is below a predetermined amount of stored electricity at the time when the operation means for operating the vehicle is stopped to stop the operation of the vehicle.

Preferably, when the internal combustion engine is operated after the vehicle is deactivated, the execution of the engine operation is announced.
As a result of performing the engine operation after stopping the operation of the vehicle, when the amount of electricity stored in the battery reaches a predetermined amount of electricity, or when a predetermined time elapses from the start of the engine operation after the operation of the vehicle is stopped, or Stops the engine operation after the operation of the vehicle is stopped when the operating means for stopping the engine operation after the operation of the vehicle is stopped.

[0009]

When the amount of stored electricity in the battery at the time the vehicle stops operating is below the predetermined amount of stored electricity, the internal combustion engine for power generation is operated and the battery is charged even after the vehicle stops operating. Therefore, the amount of stored electricity in the battery for starting the vehicle traveling is always ensured, and there is no difficulty in starting the vehicle traveling. In addition, after the vehicle starts traveling, the battery is charged as needed to improve the power performance of the vehicle and increase the cruising range of the vehicle.

Preferably, the engine operation is announced when the internal combustion engine is operated after the operation of the vehicle is stopped, and it is clarified that the engine operation is not due to a vehicle failure or the like. Further, the engine is operated after the vehicle has stopped operating until the amount of stored electricity in the battery reaches a predetermined amount of stored electricity or until a predetermined time elapses from the start of engine operation, and therefore the battery is reliably charged. Furthermore,
Engine operation after vehicle operation is stopped when a predetermined time has elapsed from the start of engine operation after vehicle operation is stopped, or when operating means for stopping engine operation after vehicle operation is stopped is operated. To stop. For this reason, engine operation in the garage where exhaust gas is easily filled and engine operation at night when noise should be suppressed can be completed within an appropriate time, and in an emergency situation, engine operation can be forced if necessary. Can be stopped automatically.

[0011]

EXAMPLES Referring to FIG. 1, a hybrid vehicle (vehicle)
Is equipped with a number of electric motors (one of which is indicated by reference numeral 10) according to its specifications. Electric motor 10
Is used as a drive source for a vehicle, and is composed of a DC motor or an AC motor, and its output shaft is drivingly connected to drive wheels (not shown) of the vehicle via a power transmission mechanism (not shown) of the vehicle. Has been done. Further, the electric motor 10 is electrically connected to a battery 20 for vehicle traveling through a current control device 50 that operates under the control of a controller 60, and normally operates by receiving power supply from the battery 20 during vehicle traveling. Then, the vehicle is driven. Further, the electric motor 10 functions as a generator during deceleration operation of the vehicle to generate deceleration recovered power, and the deceleration recovered power causes the battery 2 to operate.
It is designed to charge 0. And the electric motor 1
0 is a motor temperature sensor 1 for detecting the motor temperature
1 is attached. Further, the battery 20 is provided with a battery capacity sensor 21 for detecting a parameter representing the battery capacity, for example, a battery voltage value.

A hybrid vehicle includes a generator 30 for generating electric power for charging a battery, and an internal combustion engine 40 for driving the generator 30 having an output shaft drivingly connected to a generator rotation shaft. Further equipped. The generator 30 is composed of a DC generator or an AC generator, is electrically connected to the battery 20 via the current control device 50, and uses the power generated by the generator 30 when the internal combustion engine 40 is operating to generate the battery 2 power.
It is designed to charge 0. Further, the generator 30 includes a control unit (not shown) for adjusting the amount of power generation and stopping the power generation, and various sensors (not shown) for detecting generator operating information such as the temperature of the generator and failure status. Abbreviation) and are provided. The generator 30 functions as a so-called starter that receives electric power from the battery 20 and starts the internal combustion engine 40 when the engine is started. However, a starter for starting the engine may be provided separately from the generator 30, and in this case, the generator 30 is dedicated to power generation.

The internal combustion engine 40 for power generation is, for example, an engine body composed of a small and lightweight piston engine, a fuel supply system having a throttle valve, an ignition system and a fuel injection system, and various types electrically connected to the current control device 50. It has an engine drive system (not shown) including an actuator for starting and stopping the engine body, controlling the number of revolutions, controlling the throttle valve opening, and the like. An exhaust gas purifying device 42 is arranged on an exhaust pipe 41 that is connected to an exhaust port (not shown) of the engine 40 and discharges exhaust gas. The exhaust gas purification device 42 is a catalyst for removing harmful substances such as CO and NOx from the exhaust gas passing through the exhaust pipe 41, and an electrothermal catalyst heater connected to the battery 20 via the current control device 50. The catalyst has a very strong exhaust gas purification action when activated by being heated by a heater. A catalyst temperature sensor 43 for detecting the catalyst temperature is attached to the exhaust gas purification device 42. Further, the engine 40 is provided with various sensors (not shown) for detecting engine operating information such as engine speed, intake air amount, throttle valve opening, and the like.

As described above, the electric motor 10 and the battery 2
0, the generator 30, the internal combustion engine 40, and the current control device 5 interposed between the catalyst heaters of the exhaust gas purification device 42.
Under the control of the controller 60, 0 controls the switching of the electrical connection between the corresponding ones of the above elements and adjusts the current value and the energization direction in the power supply between the corresponding elements. Although illustration is omitted, the current control device 50 includes, for example, an input unit for inputting a current control device control signal from the controller 60, electrical connection switching sent from the input unit, and current value and energization direction adjustment. And an electric power conversion unit responsive to the control output from the adjusting unit.
Further, the current control device 50 is provided with various sensors (not shown) for detecting the temperature, failure status, etc. of the device.

The controller 60 controls various operations of the electric motor 10, the internal combustion engine 40 and the current control device 50 by inputting various kinds of operation information from the above-mentioned various components and various sensors of the hybrid vehicle. Although illustration is omitted, the controller 60 includes, for example, a processor for executing a control program to be described later, various memories for storing the control program, various data, etc., the controller 60, the above-mentioned various elements, and various sensors. And various interface circuits for exchanging signals with each other.

More specifically, the controller 60 includes a motor temperature sensor 11 provided in the electric motor 10, a battery capacity sensor 21 provided in the battery 20, a catalyst temperature sensor 43 provided in the exhaust gas purifying device 42, a generator 30, and an internal combustion engine 40. And various sensors provided in each of the current control device 50 and various sensors provided in the hybrid vehicle for detecting vehicle driving information such as vehicle speed and accelerator pedal depression amount, and a start key (not shown). ), And is electrically connected to various switches such as the engine stop switch 80. Then, the controller 60
From these sensors and switches, the motor temperature signal,
Battery capacity signal, catalyst temperature signal, generator operation information (for example, temperature of generator 30, failure status), internal combustion engine operation information (for example, engine 40 speed, intake air amount, throttle valve opening), current control device operation Information (for example, the failure status of the current control device 50) and vehicle driving information (for example, the vehicle speed and the on / off state of the start key) are input. Further, the processor controls the generator control signal related to the control of the power generation amount of the generator 30 and the stop of the power generation, the control of the start and stop of the internal combustion engine 40, the rotation speed and the like based on the various signals and information thus input. A related internal combustion engine control signal and a current control device control signal related to control of a current value, energization direction, etc. in power supply between the above-mentioned elements connected to the current control device 50 are determined, and the determined control signal is generated. Machine 30, engine 40 and current controller 50
It is designed to be sent to.

In FIG. 1, reference numeral 70 indicates the engine 4 for charging the battery after the vehicle has finished traveling.
It represents an alarm lamp for notifying the driver that 0 is being driven. Hereinafter, referring to FIGS. 2 to 7,
The operation control of the electric motor 10, the internal combustion engine 40, and the exhaust gas purification device 42 by the controller 60 will be described.

When the driver turns on the start key to operate the vehicle, the processor of the controller 60 determines the key-on operation and starts execution of the main routine shown in FIG. That is, the processor first executes a key-on procedure including reading from the memory of the control data backed up at the end of the previous vehicle travel, checking the operating states of the various components of the hybrid vehicle, and the like (step S1), Next, the traveling control subroutine shown in detail in FIG. 3 is executed (step S2).

Referring to FIG. 3, in the traveling control subroutine, the processor first reads the output of the accelerator pedal depression amount detection sensor to read the accelerator pedal depression amount θAC.
C is detected (step S21), and then it corresponds to the characteristic diagram (FIG. 6) showing the relationship between the accelerator pedal depression amount θACC and the target vehicle speed VT and is described in the control program in advance or stored in the memory of the controller 60 in advance. A target vehicle speed VT that matches the accelerator pedal depression amount θACC detected in step S21 is determined according to the calculated target vehicle speed determination formula or lookup table (step S22).

As shown in FIG. 6, the target vehicle speed VT is zero in the first depression amount region in which the accelerator pedal depression amount θACC takes a small value from zero to θACC1 to prevent the vehicle from starting and the accelerator pedal depression. The amount of depression θACC is from θACC1 to θACC2
In the second pedaling amount region that takes a slightly smaller value up to 0, as the pedaling amount θACC increases, it increases from zero to VT2 to allow a gradual start of the vehicle, and the accelerator pedal pedaling amount θ
In the third depression amount area where ACC exceeds θACC2, the depression amount θACC
Is increased from VT2 at an increase rate larger than that in the second region to allow normal running of the vehicle.

Referring again to FIG. 3, after determining the target vehicle speed VT, the processor of the controller 60 reads the vehicle speed sensor output to detect the actual vehicle speed VV (step S2).
3) Next, motor energization amount (required motor drive current value) I
Is calculated (step S24). In the calculation of the motor energization amount I, the processor first calculates the vehicle speed difference (= VV-VT) based on the actual vehicle speed VV detected in step S23 and the target vehicle speed VT determined in step S22, and then calculates the actual vehicle speed as The previously detected actual vehicle speed VV and the previously calculated vehicle speed difference (=) are calculated according to an arithmetic expression or a lookup table for determining the required vehicle body acceleration corresponding to the characteristic diagram (FIG. 7) representing the relationship between the vehicle speed difference and the required vehicle body acceleration. Determine the required vehicle body acceleration α that conforms to VV-VT).

As shown in FIG. 7, the required vehicle body acceleration α is
If the actual vehicle speed VV is higher than the target vehicle speed VT and therefore the vehicle speed difference is positive, the necessity of decelerating the vehicle becomes negative, whereas if the vehicle speed difference is negative, the necessity of acceleration driving is positive. become. Further, the absolute value of the acceleration α increases as the actual vehicle speed increases, even if the absolute value of the vehicle speed difference is constant. After determining the required vehicle body acceleration α as described above, the processor calculates the calculation formula PS = [{C · A · (VV) ² + μ · W + α · W /
g} · VV] / (K1 · η), the required motor output P
Calculate S. Here, C, A, VV, μ, W, α and η are the air resistance coefficient of the vehicle, the front projection area, the actual vehicle speed,
It represents the rolling resistance coefficient, total weight, required vehicle acceleration, and power transmission efficiency, respectively. Further, g and K1 respectively represent the gravitational acceleration and the unit conversion coefficient, and the coefficient K1 is, for example, a value 27.
Set to 0. It should be noted that the above arithmetic expression is suitable when there is no road gradient. Also, in determining the required motor output,
A lookup table for determining the motor output may be referred to instead of the computation by the above equation.

Next, the processor calculates the arithmetic expression I = (K2 ·
A required motor drive current value (motor energization amount) I is calculated according to PS) / (ηMTR · V). Where K2, PS, η
MTR and V represent the unit conversion coefficient, the required motor output, the motor efficiency of the electric motor 10 and the operating voltage of the electric motor 10, respectively, and the coefficient K2 takes a value 735, for example. In the next step S25, the processor sends a control signal representing the required motor drive current value I to the current control device 50. In response to this control signal, the current control device 50 performs, for example, duty control so that the motor drive current of the value I is supplied to the electric motor 10 from the battery 20 via the device. As a result, the actual vehicle speed VV increases or decreases to the target vehicle speed VT, or is maintained at the target vehicle speed VT. Therefore,
Immediately after the start key is turned on, if the accelerator pedal depression amount is larger than the value θACC1, the electric motor 10 starts and the vehicle starts.

Referring again to FIG. 2, after the traveling control subroutine (step S2) is completed, the processor of the controller 60 reads the battery capacity signal from the battery capacity sensor 21, and based on this, the amount of electricity stored in the battery 20 is determined. It is determined whether or not the amount of stored electricity is smaller than a predetermined amount of electricity with which the vehicle can be sufficiently driven by the electric motor 10 (step S
3). If the result of this determination is negative, that is, if the battery charge amount is greater than or equal to the predetermined charge amount and battery 20 does not need to be charged, the processor determines whether the start key has been turned off (step S4). ), If the result of this determination is negative, the process returns to the above-mentioned traveling control subroutine (step S2). On the other hand, if it is determined that the start key has been turned off, the processor executes a key-off subroutine, which will be described later in detail (step S5), and ends the main routine.

While the vehicle is running while the start key is not turned off and the required drive current is supplied to the electric motor 10 by repeating the series of steps S2 to S4, the battery charge amount falls below the predetermined charge amount. Therefore, when it is determined in step S3 that the battery needs to be charged, the processor reads the catalyst temperature signal from the catalyst temperature sensor 43, and based on this, the catalyst temperature is the predetermined temperature required to sufficiently activate the catalyst. It is determined whether or not it is less than (step S6). If the result of this determination is affirmative, and accordingly, when the internal combustion engine 40 is operated, there is a risk that exhaust gas containing harmful substances will be discharged from the engine, the processor instructs the catalyst heater of the exhaust gas purification device 42 to be energized. A control signal is sent to the current controller 50 (step S7). In response to this control signal, the current control device 50 operates so that the heating current is supplied from the battery 20 to the heater, and as a result, the catalyst heating heater is energized to heat the catalyst. After instructing to energize the heater, the processor sends an engine control signal instructing to stop the engine to the engine drive system (step S
8) As a result, the operation stop state of the internal combustion engine 40 is maintained, or if the engine is operating, the engine 40
Is stopped. Therefore, if the catalyst temperature drops for some reason during engine operation, the engine stops operating.

Next, in step S4, the processor again determines whether or not the key-off operation is performed. If the key-off operation is not performed, the processor returns to step S2 and the series of steps S2, S3, S6 to S8 and S4
Is repeatedly executed. After that, it is determined in step S6 that the catalyst temperature has reached the predetermined temperature. Therefore, when the exhaust gas purifying apparatus 42 reaches an operating state in which harmful substances can be removed from the exhaust gas by the exhaust gas purifying action of the catalyst, the processor
A control signal instructing to stop energization of the catalyst heater is sent to the current controller 50 (step S9). As a result, power supply to the heater is stopped. The processor then executes the engine control subroutine detailed in FIG. 4 (step S10).

Referring to FIG. 4, in the engine control subroutine, the processor refers to the contents of the memory of the controller 60, which indicates whether or not the engine control signal for instructing the engine operation is transmitted, to refer to the internal combustion engine 4
It is determined whether 0 is in operation (step S11
1) If the result of this determination is negative, the processor performs various controls at the time of engine start (step S112).
For example, the processor sends a current control device control signal for instructing the start of a fuel pump (not shown) to the current control device 50, and also detects the current throttle valve opening and engine detected based on the throttle valve opening sensor output. An engine control signal for instructing to drive the throttle valve only in the required angle determined from the predetermined throttle valve opening for starting and in the required direction determined in the same manner is sent to the throttle including the pulse motor of the engine drive system. Send to valve drive mechanism. As a result, the current control device 50 operates so that the required drive current is supplied from the battery 20 to the fuel pump drive motor (not shown) via the current control device 50, the fuel pump is started, and the throttle valve Is positioned at a predetermined angular position for starting the engine.

Next, the processor sends a current control device control signal instructing the engine start to the current control device 50 (step S113). As a result, the current control device 5
The current control device 50 operates so that the required drive current is supplied from the battery 20 to the starter (generator 30) via 0, whereby the generator 30 as a starter starts the internal combustion engine 40. As a result, the engine 40 drives the generator 30 and the generator 30 starts power generation.

When the engine control subroutine of this time is completed in this way, it is again determined in step S4 of the main routine (FIG. 2) whether or not the start key is turned off. If the result of this determination is affirmative, the key-off subroutine is executed in step S5, and then the execution of the main routine is terminated. On the other hand, if it is determined in step S4 that the start key has not been turned off,
The processes after the traveling control subroutine (step S2) are executed again as described above. Here, since the internal combustion engine 40 has already been started in the previous engine control subroutine, a series of steps S2, S3, S6 and S
In step S111 of the engine control subroutine (step S10) re-executed after step 9, it is determined that the engine is operating.

In this case, the processor of the controller 60 reads the preset target throttle valve opening θTRG, detects the current throttle valve opening θTH based on the throttle valve opening sensor output, and opens the current throttle valve opening θTH. It is determined whether the degree θTH exceeds the target throttle valve opening θTRG (step S114). If the result of this determination is negative, the processor sends an engine control signal for instructing the opening direction drive of the throttle valve to the engine drive system (step S115). On the other hand, throttle valve opening θTH
If it is determined in step S114 that is greater than the target throttle valve opening θTRG, the processor sends an engine control signal instructing the closing valve to be driven in the closing direction to the engine drive system (step S116). As a result, the throttle valve drive mechanism opens or closes the throttle valve of the internal combustion engine 40 according to the determination result in step S114, and the throttle valve opening is controlled to the target opening θTRG. For example, the target opening θTRG has a rotational speed of about 3
It is set to a value such that the engine 40 can be operated in a region where the operation efficiency is high at 000 rpm. Then, the step S115 related to the driving in the opening direction of the throttle valve or the step S116 related to the driving in the closing direction of the throttle valve.
In step S117 following, normal engine control including ignition timing control, fuel injection control, etc. is performed.

When the engine control subroutine is completed and returns to the main routine, as described above, the key-off subroutine (step S) is executed according to the result of the determination regarding the start key in step S4 of the main routine.
5) or a traveling control subroutine (step S2). As shown in FIG. 5, in the key-off subroutine that is started when the operation of the vehicle is stopped by the OFF operation of the start key, the processor first determines whether or not the charged amount of the battery 20 is smaller than a predetermined charged amount (step S5).
1).

If the result of this determination is negative, that is, if battery charging is not required, an internal combustion engine control signal for instructing to stop the internal combustion engine 40 is sent to the engine drive system, and the engine operation timer flag FTIME is set to stop the operation of the vehicle. The subsequent engine operating time is reset to a value "0" indicating that the engine is not timed (step S52). As a result,
If the internal combustion engine 40 is not operating, the engine stop state is maintained, and if the engine 40 is operating, the engine operation is stopped. Further, the processor executes the key-off procedure including writing the control data to the backup memory and checking the operating states of the various components of the hybrid vehicle (step S53), thereby ending the key-off subroutine.

On the other hand, if the determination result in step S51 is affirmative, that is, if battery charging is required, the processor detects the on / off state of the engine stop switch 80 and determines whether or not the switch is on (step). S54). When the switch 80 is turned on, and therefore the driver wants to prevent the engine from operating after the vehicle is stopped for some reason such as the occurrence of an emergency, the engine must be charged even when it is determined in step S51 that battery charging is required. The start or continuation of the operation is forcibly stopped and the key-off action is executed (steps S52 and S5).
3) The key off subroutine is completed.

After it is determined in step S51 that battery charging is required, in step S54 the engine stop switch 8
When determining that 0 is off, the processor further determines whether or not the engine operation timer flag FTIME has a value "1" indicating that the engine operation time after the operation of the vehicle is stopped is measured (1). Step S55). Immediately after the execution of the key-off subroutine, the flag FTIME is reset to the value "0", so the determination result in step S55 is negative. In this case, the processor sets the flag FTIME to the value "1" and resets and starts the engine operation timer T for measuring the engine operation time after the vehicle is stopped (step S56), and then the timer. It is determined whether T has reached a predetermined time TSET for engine operation after the vehicle has stopped operating (step S5).
7).

Immediately after the engine operation timer T is reset, the predetermined timer time TSET has not been reached, so the determination result in step S57 is negative. The processor then sends an alarm output to the alarm lamp 70,
The alarm lamp 70 is turned on to notify the driver that the engine operation after the vehicle has stopped is not due to a vehicle failure or the like (step S58). Next, the processor executes an engine control subroutine similar to the engine control subroutine shown in FIG. 4 (step S59), whereby the operation of the engine 40 is started and the battery 2
0 charging starts.

After that, the above-mentioned series of steps S51, S5
4, S55 and S57 to S59 are repeatedly executed, and the battery charging by the engine operation is continued. Then, if it is determined in step S51 that the predetermined battery charge amount has been reached, or if it is determined in step S57 that the predetermined timer time TSET has been reached, the engine operation is stopped and the key-off procedure is executed. (Steps S52 and S53), the key-off subroutine ends. If the engine stop switch 80 is turned on before the predetermined battery charge amount is reached or before the predetermined timer time TSET is reached, the engine operation is forcibly stopped and the battery charging is stopped (step S5).
2).

To summarize the above-described operation control of various components of the hybrid vehicle by the controller 60, the calculation of the energization amount to the electric motor 10 and the control of the motor energization amount are started according to the ON operation of the start key. ,afterwards,
This motor control is periodically performed. As a result, the hybrid vehicle that uses the electric motor 10 as a drive source runs.
While the vehicle is traveling, if the amount of electricity stored in the battery 20 for traveling the vehicle is sufficient, the internal combustion engine 40 for driving the generator 30 is deactivated, thereby preventing unnecessary exhaust of exhaust gas. On the other hand, if there is a risk that the amount of electricity stored in the battery 20 will be insufficient, the engine 40 is started, and thereby the generator 30 generates electric power and the battery 20 is charged with the generated electric power. However, the catalyst temperature is checked when the engine is started, and if the catalyst temperature has not reached the temperature at which the catalyst is activated, the catalyst heating heater is energized to heat the catalyst. After that, when the start key is turned off, the above-mentioned motor control is ended and the vehicle running by the electric motor 10 is stopped, and it is determined in the key-off subroutine whether or not the battery charge amount is smaller than the predetermined charge amount. ..
If the predetermined battery charge amount has not been reached, the battery is charged up to the predetermined battery charge amount, thereby reliably charging the battery. Since such battery charging is performed as needed every time the vehicle travel ends, the vehicle travel can be performed by supplying power from only the battery 20 at the start of the next vehicle travel. Further, since the amount of stored electricity in the battery can be maintained at a required level, the power performance of the vehicle is improved and the cruising range of the vehicle is increased. The engine operation for charging the battery is performed for a predetermined time. Further, when the driver turns off the engine stop switch provided separately from the start key, the start or the continuation of the battery charging after the end of traveling of the vehicle is forcibly blocked.

The present invention is not limited to the above embodiment, but various modifications can be made. For example, in the embodiment, the alarm lamp is lit to notify the engine operation for charging the battery after the vehicle has finished traveling, but instead of this, for example, an alarm buzzer may be rung.

[0039]

As described above, according to the present invention, in a hybrid vehicle having an electric motor for driving a vehicle, which is supplied with electric power from a battery, and an internal combustion engine for power generation, an operating means for stopping the operation of the vehicle, for example, start When the key is operated and the vehicle stops operating, the internal combustion engine for power generation is operated when the battery charge amount is below the predetermined charge amount, so the battery charge amount for starting vehicle running is always It is secured and there is no difficulty in starting the vehicle running.

Preferably, when the internal combustion engine is operated after the operation of the vehicle is stopped, the execution of the engine operation is notified, so that it can be clarified that the engine operation after the operation of the vehicle is not due to a vehicle failure or the like. As a result of performing the engine operation after stopping the operation of the vehicle, when the amount of electricity stored in the battery reaches a predetermined amount of electricity, or when a predetermined time elapses from the start of the engine operation after the operation of the vehicle is stopped, or The operating means for stopping the engine operation after the operation of the vehicle is stopped, for example, when the engine stop switch is operated, the engine operation after the operation of the vehicle is stopped, so that the battery can be reliably charged, Further, for example, the engine operation in the garage where the exhaust gas is easily filled and the engine operation at night when noise should be suppressed can be completed within an appropriate time, and further, the engine operation can be forcibly stopped if necessary.

[Brief description of drawings]

FIG. 1 is a schematic diagram showing a main part of a hybrid vehicle to which an internal combustion engine operating method for power generation according to an embodiment of the present invention is applied.

FIG. 2 is a flowchart showing a main routine of a procedure of operation control of an electric motor for driving a vehicle, an internal combustion engine for power generation, and a catalyst heater, which is executed by the controller shown in FIG.

FIG. 3 is a flowchart showing in detail the traveling control subroutine shown in FIG.

FIG. 4 is a flowchart showing in detail the engine control subroutine shown in FIG.

5 is a detailed flowchart of the key-off subroutine shown in FIG. 2. FIG.

FIG. 6 is a characteristic diagram showing a relationship between an accelerator pedal depression amount θACC and a target vehicle speed VT used in a traveling control subroutine.

FIG. 7 is an actual vehicle speed V used in a traveling control subroutine.
FIG. 5 is a characteristic diagram showing a relationship between V, a vehicle speed difference VV-VT, and a vehicle body acceleration α.

[Explanation of symbols]

 10 Electric Motor 11 Motor Temperature Sensor 20 Battery 21 Battery Capacity Sensor 30 Generator 40 Internal Combustion Engine 41 Exhaust Pipe 42 Exhaust Gas Purification Device 43 Catalyst Temperature Sensor 50 Current Control Device 60 Controller 70 Alarm Lamp 80 Engine Stop Switch VV Actual Vehicle Speed θACC Accelerator Pedal Depression amount

Claims (5)

[Claims] 1. A hybrid vehicle having an electric motor for driving a vehicle, which is supplied with electric power from a battery, and an internal combustion engine for power generation, at the time when the operation means for stopping the operation of the vehicle is operated and the operation of the vehicle is stopped. The method of operating an internal combustion engine for power generation of a hybrid vehicle, comprising: operating the internal combustion engine for power generation when the amount of power storage of the battery is less than a predetermined amount of power storage. 2. The method of operating an internal combustion engine for power generation of a hybrid vehicle according to claim 1, further comprising notifying execution of engine operation when operating the internal combustion engine after the operation of the vehicle is stopped. 3. The engine operation is stopped when the amount of electricity stored in the battery reaches the predetermined amount of electricity as a result of performing the engine operation after stopping the operation of the vehicle. A method of operating an internal combustion engine for power generation of a hybrid vehicle. 4. The internal combustion engine for power generation of a hybrid vehicle according to claim 1, wherein the engine operation is stopped when a predetermined time has elapsed from the start time of the engine operation after the operation of the vehicle was stopped. how to drive. 5. The engine operation after the operation stop of the vehicle is stopped when an operation means for stopping the engine operation after the operation stop of the vehicle is operated. For operating an internal combustion engine for power generation in a hybrid vehicle of the above.