VEHICLE ELECTRIC POWER SUPPLY APPARATUS

• US 20150001857A1
• Filed: 06/26/2014
• Published: 01/01/2015
• Est. Priority Date: 07/01/2013
• Status: Active Grant

• Current Assignee: Honda Motor Co., Ltd. (Honda Motor Company)
• Original Assignee: Honda Motor Co., Ltd. (Honda Motor Company)
• Inventors: Sekiguchi, Satoshi
• Granted Patent: US 9,458,813 B2
• Time in Patent Office: Days
• US Class Current: 290/38.C
• CPC Class Codes: B60L 58/20 having different nominal voltages
• CPC Class Codes: B60L 7/10 Dynamic electric regenerative braking B60L7/22 takes precedence
• CPC Class Codes: B60R 16/03 for supply of electrical power to vehicle subsystems or for circuit arrangements for charging batteries H02J7/00
• CPC Class Codes: F02N 11/04 the motors being associated with current generators
• CPC Class Codes: F02N 11/0814 comprising means for controlling automatic idle-start-stop
• CPC Class Codes: F02N 11/0825 related to prevention of engine restart failure, e.g. disabling automatic stop at low battery state
• CPC Class Codes: F02N 11/0844 with means for restarting the engine directly after an engine stop request, e.g. caused by change of driver mind
• CPC Class Codes: F02N 11/0848 with means for detecting successful engine start, e.g. to stop starter actuation
• CPC Class Codes: F02N 11/0866 comprising several power sources, e.g. battery and capacitor or two batteries
• CPC Class Codes: F02N 11/087 Details of the switching means in starting circuits, e.g. relays or electronic switches
• CPC Class Codes: F02N 11/108 for diagnosis of the starter or its components
• CPC Class Codes: F02N 2011/0874 characterised by said switch being an electronic switch
• CPC Class Codes: F02N 2011/0885 Capacitors, e.g. for additional power supply
• CPC Class Codes: F02N 2011/0888 DC/DC converters
• CPC Class Codes: F02N 2200/022 Engine speed
• CPC Class Codes: F02N 2200/063 Battery voltage
• CPC Class Codes: Y02T 10/40 Engine management systems
• CPC Class Codes: Y02T 10/70 Energy storage systems for electromobility, e.g. batteries

Abstract

A control unit of a vehicle electric power supply apparatus controls an opening and closing unit to set a switch to an OFF state and a voltage detection unit to detect an output voltage of a first power source and an output voltage of a second power source when a second electric load is to be driven, and the control unit inhibits driving of the second electric load when the absolute value of the difference between the output voltage of the first power source and the output voltage of the second power source detected by the voltage detection unit is a predetermined first threshold value or less over a predetermined length of time.

Claims

1. A vehicle electric power supply apparatus comprising:

a first power source;

a second power source that is connected in parallel to the first power source;

a DC-DC converter that is connected between the first power source and the second power source;

a switch that is connected in parallel to the DC-DC converter and is connected between the first power source and the second power source;

an opening and closing unit that is used to open and close the switch;

a voltage detection unit used to detect an output voltage of the first power source and an output voltage of the second power source;

a first electric load that is connected to the first power source;

a second electric load that is connected to the second power source and needs to be supplied with a current which is greater than that of the first electric load;

and a control unit that controls the DC-DC converter, the opening and closing unit, and the second electric load, wherein

the control unit controls the opening and closing unit to set the switch to an OFF state and the voltage detection unit to detect an output voltage of the first power source and an output voltage of the second power source when the second electric load is to be driven, and

the control unit inhibits driving of the second electric load when the absolute value of the difference between the output voltage of the first power source and the output voltage of the second power source detected by the voltage detection unit is a predetermined first threshold value or less over a predetermined length of time.

2. The vehicle electric power supply apparatus according to claim 1, wherein

the vehicle electric power supply apparatus is mounted in a vehicle provided with an internal combustion engine, and

the second electric load is an electric motor that is used to start the internal combustion engine.

3. The vehicle electric power supply apparatus according to claim 1, wherein

the vehicle electric power supply apparatus is mounted in a vehicle, the vehicle being provided with an internal combustion engine and an idle stopping unit that is used to execute idle stopping in which the internal combustion engine is temporarily stopped, and

the idle stopping unit inhibits execution of the idle stopping when the absolute value of the difference between the output voltage of the first power source and the output voltage of the second power source detected by the voltage detection unit is the predetermined first threshold value or less over the predetermined length of time.

4. The vehicle electric power supply apparatus according to claim 1, wherein

the vehicle electric power supply apparatus is mounted in a vehicle, and

the control unit removes driving inhibition of the second electric load during stopping of the vehicle.

5. A vehicle electric power supply apparatus mounted in a vehicle provided with an internal combustion engine, the apparatus comprising:

a first power source;

a second power source that is connected in parallel to the first power source;

a DC-DC converter that is connected between the first power source and the second power source;

a switch that is connected in parallel to the DC-DC converter and is connected between the first power source and the second power source;

an opening and closing unit that is used to open and close the switch;

a control unit that controls the DC-DC converter and the opening and closing unit;

an electric motor that is connected to the second power source and is used to start the internal combustion engine;

and a rotation frequency detection unit that is used to detect a rotation frequency of the internal combustion engine, wherein

the control unit controls the opening and closing unit to set the switch to an ON state when the rotation frequency detected by the rotation frequency detection unit after a predetermined length of time elapses in the starting of the internal combustion engine by the electric motor is a predetermined second threshold value or less.

6. The vehicle electric power supply apparatus according to claim 5, wherein

the vehicle electric power supply apparatus is mounted in the vehicle provided with an idle stopping unit that is used to execute idle stopping in which the internal combustion engine is temporarily stopped, and

the idle stopping unit inhibits next execution of the idle stopping when the rotation frequency detected by the rotation frequency detection unit after the predetermined length of time elapses in the starting of the internal combustion engine by the electric motor is the predetermined second threshold value or less.