Electric circuit

Patent metadata

Field	Value
Publication number	US-9944199-B2
Application number	US-201315039264-A
Country	US
Kind code	B2
Filing date	Nov 27, 2013
Priority date	Nov 27, 2013
Publication date	Apr 17, 2018
Grant date	Apr 17, 2018

Abstract

An electric circuit used in a vehicle having an idling stop function of automatically stopping and automatically restarting an engine includes an electric generator, a first electricity storage capable of charging and discharging electric power generated by the electric generator, a second electricity storage connected in parallel to the first electricity storage, capable of charging and discharging the generated electric power, and having high durability against repetitive charge and discharge compared to the first electricity storage, an engine restarter, which is connected to the first electricity storage and the second electricity storage, configured to crank the engine at a time of the automatic restart, and a switch, which is connected between the engine restarter and the first electricity storage, configured to block a flow of current between the engine restarter and the first electricity storage. The switch includes at least a semiconductor switch.

First claim

The invention claimed is:

1. An electric circuit used in a vehicle having an idling stop function of automatically stopping and automatically restarting an engine, the electric circuit comprising:
an electric generator;
a lead battery capable of charging and discharging electric power generated by the electric generator;
a non-aqueous electrolyte secondary battery connected in parallel to the lead battery, capable of charging and discharging the generated electric power, and having high durability against repetitive charge and discharge compared to the lead battery;
an engine restarter, which is connected to the lead battery and the non-aqueous electrolyte secondary battery, configured to crank the engine at a time of the automatic restart; and
a switch, which is connected between the engine restarter and the lead battery, configured to block a flow of current between the engine restarter and the lead battery,
wherein the switch comprises at least a semiconductor switch,
wherein at the time of the automatic restart, the switch blocks the flow of current between the engine restarter and the lead battery, and the engine restarter is driven by the electric power supplied from the non-aqueous electrolyte secondary battery,
wherein the semiconductor switch includes a parasitic diode, and is connected such that a forward direction of the parasitic diode matches a direction from the non-aqueous electrolyte secondary battery toward the lead battery,
wherein the switch comprises a first relay in addition to the semiconductor switch,
wherein the first relay is connected in parallel to the semiconductor switch, and
wherein the semiconductor switch is closed and the first relay is opened when the engine has been automatically stopped, and the semiconductor switch is opened at the time of the automatic restart.

2. An electric circuit used in a vehicle having an idling stop function of automatically stopping and automatically restarting an engine, the electric circuit comprising:
an electric generator;
a first electricity storage capable of charging and discharging electric power generated by the electric generator;
a second electricity storage connected in parallel to the first electricity storage, capable of charging and discharging the generated electric power, and having high durability against repetitive charge and discharge compared to the first electricity storage;
an engine restarter, which is connected to the first electricity storage and the second electricity storage, configured to crank the engine at a time of the automatic restart; and
a switch, which is connected between the engine restarter and the first electricity storage, configured to block a flow of current between the engine restarter and the first electricity storage,
wherein the switch comprises at least a semiconductor switch,
wherein at the time of the automatic restart, the switch blocks the flow of current between the engine restarter and the first electricity storage, and the engine restarter is driven by the electric power supplied from the second electricity storage,
wherein the semiconductor switch includes a parasitic diode, and is connected such that a forward direction of the parasitic diode matches a direction from the second electricity storage toward the first electricity storage,
wherein the switch comprises a first relay in addition to the semiconductor switch,
wherein the first relay is connected in parallel to the semiconductor switch,
wherein the semiconductor switch is closed and the first relay is opened when the engine has been automatically stopped, and the semiconductor switch is opened at the time of the automatic restart,
wherein electric loads of the vehicle are connected to be on the same side as the first electricity storage relative to the switch,
wherein the electric generator is connected to be on the same side as the second electricity storage relative to the switch,
wherein a second relay is connected between the second electricity storage and the engine restarter, and the second relay is capable of blocking a flow of current between the engine restarter and the second electricity storage,
wherein the first relay is of a normally closed type, and is in a closed state when current is blocked from flowing through a coil thereof, and
wherein the second relay is of a normally open type, and is in an open state when current is blocked from flowing through a coil thereof.

3. The electric circuit according to claim 2 ,
wherein the electric loads are categorized into a first load group and a second load group, the first load group and the second load group are respectively capable of and incapable of tolerating actuation under a voltage sag at the time of the automatic restart, the first load group is connected to be on the same side as the second electricity storage relative to the switch, and the second load group is connected to be on the same side as the first electricity storage relative to the switch.

4. The electric circuit according to claim 1 ,
wherein the engine restarter is realized by the electric generator provided with a function as a driving motor, and connected to be on the same side as the non-aqueous electrolyte secondary battery relative to the switch,
wherein a starter motor and electric loads of the vehicle are connected to be on the same side as the lead battery relative to the switch, and the starter motor cranks the engine when the engine is started by a startup manipulation performed by a driver,
wherein a second relay is connected between the non-aqueous electrolyte secondary battery and the engine restarter, and the second relay is capable of blocking a flow of current between the engine restarter and the non-aqueous electrolyte secondary battery,
wherein the first relay is of a normally closed type, and is in a closed state when current is blocked from flowing through a coil thereof, and
wherein the second relay is of a normally open type, and is in an open state when current is blocked from flowing through a coil thereof.

5. The electric circuit according to claim 1 ,
wherein electric loads of the vehicle are connected to be on the same side as the lead battery relative to the switch,
wherein the electric generator is connected to be on the same side as the non-aqueous electrolyte secondary battery relative to the switch,
wherein a second relay is connected between the non-aqueous electrolyte secondary battery and the engine restarter, and the second relay is capable of blocking a flow of current between the engine restarter and the non-aqueous electrolyte secondary battery,
wherein the first relay is of a normally open type, and is in an open state when current is blocked from flowing through a coil thereof, and
wherein the second relay is of a normally open type, and is in an open state when current is blocked from flowing through a coil thereof.

6. The electric circuit according to claim 1 ,
wherein electric loads of the vehicle are connected to be on the same side as the lead battery relative to the switch,
wherein the electric generator is connected to be on the same side as the non-aqueous electrolyte secondary battery relative to the switch,
wherein the non-aqueous electrolyte secondary battery and the electric generator are directly connected without any relay mediating therebetween, and
wherein the first relay is of a normally closed type, and is in a closed state when current is blocked from flowing through a coil thereof.

7. The electric circuit according to claim 1 ,
wherein electric loads of the vehicle are connected to be on the same side as the lead battery relative to the switch,
wherein the electric generator is connected to be on the same side as the lead battery relative to the switch,
w

Assignees

• Nissan Motor

Inventors

• Tahara Masahiko

Classifications

• F02N11/0814

  comprising means for controlling automatic idle-start-stop · CPC title

• F02N11/006

  using a plurality of electric motors · CPC title

• H01M10/44

  Methods for charging or discharging (circuits for charging H02J7/00) · CPC title

• F02N11/04

  the motors being associated with current generators · CPC title

• F02N11/087

  Details of the switching means in starting circuits, e.g. relays or electronic switches · CPC title