Control method for hybrid vehicle and control apparatus for hybrid vehicle

1. A control method for a hybrid vehicle including a generator and an electric motor, the generator being configured to charge a battery by use of power of an engine, wherein the engine, the electric motor, and the battery are arranged in a series configuration such that the electric motor drives driving wheels by electric power of the battery and mechanical power from the engine is transferred to the generator rather than to the driving wheels, the control method comprising:

accepting mode setting to set any of a normal mode, a regeneration driving mode, and a silent mode in accordance with an operation on a mode switch,

the normal mode being a mode in which the battery is charged by charging by the generator by use of the power of the engine or by charging by a regenerative braking force in the electric motor,

the regeneration driving mode being a mode in which the battery is charged by charging by use of the power of the engine similarly to the normal mode or by charging by a regenerative braking force larger than the regenerative braking force in the normal mode, whereby the regenerative braking force in the normal mode is inhibited relative to the regenerative braking force in the regeneration driving mode,

the silent mode being a mode in which charging by use of the power of the engine is inhibited, wherein:

when the normal mode is set, setting of the silent mode is not accepted; and

when the regeneration driving mode is set, setting of the silent mode is accepted.

2. The control method for the hybrid vehicle, according to claim 1 , further comprising:

accepting mode setting to set a charge mode in which power generation is performed by the generator, wherein:

when the normal mode is set, setting of the charge mode is not accepted; and

when the regeneration driving mode is set, setting of the charge mode is accepted.

3. The control method for the hybrid vehicle, according to claim 1 , wherein:

the hybrid vehicle includes a brake pedal configured such that a stepping operation is assisted by negative pressure generated in an intake passage of the engine to restrain motoring of the engine and thereby maintain silence of the hybrid vehicle; and

when generation of negative pressure to assist the brake pedal is required, the negative pressure is generated in the intake passage by performing a control such that the generator is driven by the battery to cause the engine to idle.

4. The control method for the hybrid vehicle, according to claim 1 , wherein:

when a charging amount of the battery becomes lower than a lower limit, the engine is driven to charge the battery by the generator;

in a case where the regeneration driving mode is selected, when the charging amount exceeds a first predetermined value larger than the lower limit, selection of the silent mode is accepted; and

in a case where the silent mode is selected, when the charging amount is lower than a second predetermined value larger than the lower limit but smaller than the first predetermined value, the silent mode is cancelled, and the regeneration driving mode is set.

5. A control apparatus for a hybrid vehicle including a generator, an electric motor, and a mode switch, the generator being configured to charge a battery by use of power of an engine, wherein the engine, the electric motor, and the battery are arranged in a series configuration such that the electric motor drives driving wheels by electric power of the battery and mechanical power from the engine is transferred to the generator rather than to the driving wheels, the mode switch being configured to set an operation mode for the generator and the electric motor, wherein:

the control apparatus is configured to accept mode setting to set any of a normal mode, a regeneration driving mode, and a silent mode via an operation on the mode switch,

the normal mode being a mode in which the battery is charged by charging by the generator by use of the power of the engine or by charging by a regenerative braking force in the electric motor,

the regeneration driving mode being a mode in which the battery is charged by charging by use of the power of the engine similarly to the normal mode or by charging by a regenerative braking force larger than the regenerative braking force in the normal mode, whereby the regenerative braking force in the normal mode is inhibited relative to the regenerative braking force in the regeneration driving mode,

the silent mode being a mode in which charging by use of the power of the engine is inhibited;

when the normal mode is set, the control apparatus does not accept setting of the silent mode; and

when the regeneration driving mode is set, the control apparatus accepts setting of the silent mode.

6. The control apparatus for the hybrid vehicle, according to claim 5 , wherein:

the control apparatus is configured to further accept setting of a charge mode in which power generation is performed by the generator in accordance with the mode setting;

when the normal mode is set, the control apparatus does not accept setting of the charge mode; and

when the regeneration driving mode is set, the control apparatus accepts setting of the charge mode.

7. The control apparatus for the hybrid vehicle, according to claim 5 , wherein:

the hybrid vehicle includes a brake pedal configured such that a stepping operation is assisted by negative pressure generated in an intake passage of the engine; and

when generation of negative pressure to assist the brake pedal is required, the control apparatus performs a motoring control such that the generator is driven by the battery to cause the engine to idle so that the negative pressure is generated in the intake passage.

8. The control apparatus for the hybrid vehicle, according to claim 5 , wherein:

when a charging amount of the battery becomes lower than a lower limit, the control apparatus drives the engine to charge the battery by the generator;

in a case where the regeneration driving mode is selected, when the charging amount exceeds a first predetermined value larger than the lower limit, the control apparatus accepts selection of the silent mode; and

in a case where the silent mode is selected, when the charging amount is lower than a second predetermined value larger than the lower limit but smaller than the first predetermined value, the control apparatus cancels the silent mode and sets the regeneration driving mode.

9. The control method for the hybrid vehicle, according to claim 1 , further comprising receiving a signal, which is indicative of a selected driving mode, in a vehicle controller configured to prevent setting of the silent mode when the normal mode is set and accept setting of the silent mode when the regeneration driving mode is set.

10. The control method for the hybrid vehicle, according to claim 9 , further comprising communicating the signal from the mode switch to the vehicle controller.

11. The control method for the hybrid vehicle, according to claim 9 , wherein accepting a mode setting includes using an installed computer program on the vehicle controller to automatically prevent setting of the silent mode when the normal mode is set and automatically accept setting of the silent mode when the regeneration driving mode is set.

12. The control apparatus for the hybrid vehicle, according to claim 5 , wherein the mode switch is located externally of the control apparatus.

13. The control apparatus for the hybrid vehicle, according to claim 5 , wherein the control apparatus includes an installed computer program such that the control apparatus automatically prevents setting of the silent mode when the normal mode is set and automatically accepts setting of the silent mode when the regeneration driving mode is set.