Method and apparatus for starting an engine using capacitor supplied voltage

• US 6,325,035 B1
• Filed: 09/30/1999
• Issued: 12/04/2001
• Est. Priority Date: 09/30/1999
• Status: Expired due to Fees

• Current Assignee: Caterpillar Incorporated
• Original Assignee: Caterpillar Incorporated
• Inventors: Codina, George, Richards, Thomas J.
• Primary Examiner(s): Dolinar, Andrew M.
• Application Number:
  US09/409,572
• Time in Patent Office: 796 Days
• Field of Search: 123/179.1, 123/179.3, 123/179.25, 290/38.R
• US Class Current: 123/179.1
• CPC Class Codes: F02N 11/0866 comprising several power sources, e.g. battery and capacitor or two batteries
• CPC Class Codes: F02N 2011/0885 Capacitors, e.g. for additional power supply
• CPC Class Codes: F02N 2011/0888 DC/DC converters

Abstract

A method and apparatus for starting an internal combustion engine using energy stored in a capacitor. The method and apparatus includes at least one battery for providing energy at a low voltage, an inverter for receiving the energy at the low voltage and producing energy at a high voltage, a capacitor for receiving and storing the energy at the high voltage, means for removing the low voltage source from the inverter, and at least one starter motor adapted to receive the energy at the high voltage from the capacitor and responsively start the engine.

Claims

1. A method for starting an internal combustion engine using energy stored in a capacitor, including the steps of:

providing energy at a low voltage from at least one battery to an inverter;

boosting the energy at the low voltage to energy at a high voltage, the high voltage being greater than 100 volts;

delivering the energy at the high voltage from the inverter to a capacitor;

automatically removing the low voltage source from the inverter during the period of time the engine is being started; and

delivering the energy at the high voltage from the capacitor to at least one starter motor to responsively start the engine.

2. A method, as set forth in claim 1, wherein providing energy at a low voltage includes the step of providing energy at about 12 to 36 volts to the inverter.

3. A method, as set forth in claim 1, wherein delivering the energy at the high voltage from the capacitor to at least one starter motor includes the step of delivering the energy at the high voltage to a high voltage starter motor.

4. A method, as set forth in claim 1, wherein delivering the energy at the high voltage from the capacitor to at least one starter motor includes the step of delivering a portion of the energy at the high voltage to a low voltage starter motor.

5. A method, as set forth in claim 1, wherein delivering the energy at the high voltage from the capacitor to at least one starter motor includes the step of delivering the energy at the high voltage to a plurality of starter motors.

6. A method, as set forth in claim 5, wherein the plurality of starter motors are low voltage starter motors connected in series.

7. A method, as set forth in claim 1, wherein providing energy at a low voltage includes the step of providing energy at a low voltage over a long period of time.

8. A method, as set forth in claim 7, wherein a long period of time is about 180 seconds.

9. A method, as set forth in claim 1, wherein delivering the energy at the high voltage from the capacitor to at least one starter motor includes the step of delivering the energy at the high voltage over a short period of time.

10. A method, as set forth in claim 9, wherein a short period of time is about 18 seconds.

11. A method, as set forth in claim 1, further including the step of discharging the energy at the high voltage from the capacitor in response to a predetermined condition.

12. A method, as set forth in claim 11, wherein the predetermined condition is the internal combustion engine being accessed by a person.

13. An apparatus for starting an internal combustion engine using voltage stored in a capacitor, comprising:

at least one battery for providing energy at a low voltage;

a DC to DC inverter for receiving the energy at the low voltage and producing energy at a high voltage, the high voltage being greater than 100 volts;

a capacitor for receiving and storing the energy at the high voltage;

means for automatically removing the low voltage source from the inverter during the period of time the engine is being started; and

at least one starter motor adapted to receive the energy at the high voltage from the capacitor and responsively start the engine.

14. An apparatus, as set forth in claim 13, wherein the low voltage is about 12-36 volts.

15. An apparatus, as set forth in claim 13, wherein the at least one starter motor is a high voltage starter motor.

16. An apparatus, as set forth in claim 13, wherein the at least one starter motor is a low voltage starter motor.

17. An apparatus, as set forth in claim 13, wherein the at least one starter motor is a plurality of starter motors.

18. An apparatus, as set forth in claim 17, wherein the plurality of starter motors are low voltage starter motors connected in series.

19. An apparatus, as set forth in claim 13, further including means for discharging the energy at the high voltage from the capacitor in response to a predetermined condition.

20. An apparatus, as set forth in claim 19, wherein the means for discharging the energy at the high voltage from the capacitor is a bleeder resistor connected in parallel with the capacitor.

21. An apparatus, as set forth in claim 20, wherein the predetermined condition is the internal combustion engine being accessed by a person.

22. An apparatus, as set forth in claim 13, further including a current control inductor electrically connected between the capacitor and the at least one starter motor.

23. An apparatus, as set forth in claim 13, wherein the means for automatically removing the low voltage source from the inverter includes a charging switch coupled to a starter switch.

24. An apparatus, as set forth in claim 23, wherein the charging switch is adapted to open when the starter switch is closed.