Internal combustion engine control system for vehicle and control method thereof

• US 20020195822A1
• Filed: 05/31/2002
• Published: 12/26/2002
• Est. Priority Date: 06/07/2001
• Status: Active Grant

• Current Assignee: Mitsubishi Denki Kabushiki Kaisha (Mitsubishi Electric Corporation)
• Original Assignee: Mitsubishi Denki Kabushiki Kaisha (Mitsubishi Electric Corporation)
• Inventors: Sumimoto, Katsuyuki
• Granted Patent: US 6,975,046 B2
• Time in Patent Office: Days
• US Class Current: 290/41
• CPC Class Codes: H02J 1/14 Balancing the load in a network
• CPC Class Codes: H02J 7/00308 Overvoltage protection
• CPC Class Codes: H02J 7/0047 with monitoring or indicating devices or circuits
• CPC Class Codes: H02J 7/14 for charging batteries from dynamo-electric generators driven at varying speed, e.g. on vehicle
• CPC Class Codes: H02P 9/04 Control effected upon non-electric prime mover and dependent upon electric output value of the generator
• CPC Class Codes: H02P 9/06 Control effected upon clutch or other mechanical power transmission means and dependent upon electric output value of the generator

Abstract

An internal combustion engine control system for vehicle prevents an electronic device from being damaged due to over-voltage failure of a generator, and enables the vehicle to continue to travel. Over-voltage failure of a vehicle generator (3) is detected from a voltage generated by the vehicle generator (3) and a voltage of a battery (4). When detecting any over-voltage failure, a maximum engine speed limiting apparatus (13) for preventing over speed of an internal combustion engine (1) is controlled to suppress the engine speed. Any electric load that consumes a relatively large current and does not make the traveling dangerous such as headlight (5) or heater heating wire (6) is applied to suppress the over-voltage. The electric load to be applied is increased or decreased depending on magnitude of the over-voltage. Thus the vehicle can continues traveling even if any over-voltage failure occurs.

Claims

1. An internal combustion engine control system for vehicle comprising:

power generation information monitor means for monitoring a power generation information including a voltage generated by a vehicle generator driven by means of an internal combustion engine;

maximum engine speed limiting means for imposing a limit on a maximum engine speed of said internal combustion engine using a command signal; and

secondary failure avoiding control means for feeding said command signal to said maximum engine speed limiting means and maintaining the voltage generated by said vehicle generator at a normal value to avoid a secondary failure due to abnormality in said generated voltage in the case where it is determined that said generated voltage exceeds a predetermined value.

3. The internal combustion engine control system for vehicle according to claim 1;

wherein the system includes electric load control means for ON/OFF controlling an electric load that receives a power supply from said battery; and

said secondary failure avoiding control means controls said maximum engine speed limiting means and said electric load control means thereby controlling a revolving speed of said vehicle generator and an electric load, and maintains said generated voltage at a normal value to avoid the secondary failure, in the case where it is determined that said generated voltage exceeds a predetermined value.

4. The vehicle internal combustion engine system according to claim 1, wherein it is determined that there is any abnormality in said generated voltage or said battery voltage when said generated voltage and/or said battery voltage continues to be over a predetermined value during a predetermined period of time.

5. The vehicle internal combustion engine system according to claim 3, wherein control of said electric load control means executed by said secondary failure avoiding control means is carried out in such a manner that said electric load may be ON or OFF without manipulation of vehicle driver.

6. The vehicle internal combustion engine system according to claim 5, wherein among said electric loads mounted on said vehicle, an electric load having been manipulated by said vehicle driver is excluded from being controlled by said electric load control means.

7. The internal combustion engine control system for vehicle according to claim 4, wherein said electric load controlled by said electric load control means is selected among the electric loads mounted on said vehicle, said selected electric load consuming a large electric power and not falling into a dangerous state even if applied without manipulation of the vehicle driver.

8. The internal combustion engine control system for vehicle according to claim 7, wherein said electric load controlled by said electric load control means is any of headlight, heater heating wire, cooler compressor motor, window defroster heating wire and cooling fan motor of said vehicle.

9. The internal combustion engine control system for vehicle according to claim 4, wherein said electric loads controlled by said electric load control means are respectively provided with switching means, and each of said switching means is controlled in response to a command signal from said electric load control means.

10. The internal combustion engine control system for vehicle according to claim 9, wherein said electric loads controlled by said electric load control means are respectively provided with identification means for identifying a personal code, and the command signal from said electric load control means at least comprises an identification code of an object to be controlled and a command code of ON or OFF.

11. The internal combustion engine control system for vehicle according to claim 4, wherein said secondary failure avoiding control means controls said electric load control means to monitor operation time of said electric load under an ON state, and switches one electric load to another when operation time of said electric load exceeds a predetermined value.

12. The internal combustion engine control system for vehicle according to claim 4, wherein said secondary failure avoiding control means monitors temperature of said electric load under the ON state by controlling said electric load control means, and switches one electric load to another when the temperature of said electric load exceeds a predetermined value.

13. The internal combustion engine control system for vehicle according to claim 4, wherein said secondary failure avoiding control means that controls said maximum engine speed limiting means and said electric load control means monitors a traveling state of said vehicle, controls a limit value of a maximum engine speed by said maximum engine speed limiting means in accordance with said traveling state as well as controls said electric load to be ON in accordance with the limit value of said maximum engine speed.

14. The internal combustion engine control system for vehicle according to claim 3, wherein in the case where any abnormality in said generated voltage and said battery voltage has been solved, after determining that said generated voltage and said battery voltage get into said abnormality and exceed a predetermined value and starting control operation by said secondary failure avoiding control means, the control operation by said secondary failure avoiding control means is stopped.

15. The internal combustion engine control system for vehicle according to claim 14, wherein the system includes alarm display means for indicating any abnormality when determining that said generated voltage and said battery voltage exceed a predetermined value, and said alarm display means continues to indicate the abnormality even when the abnormality in said generated voltage and said battery voltage is solved after operation of the secondary failure avoiding control means.

16. The internal combustion engine control system for vehicle according to claims 1, wherein said vehicle comprises a control device for a traveling system to control automatic transmission, and said secondary failure avoiding control means commands said control device for the traveling system to reduce a revolving speed for gear change control in said automatic transmission when determining that said generated voltage and/or said battery voltage exceeds a predetermined value.

2. An internal combustion engine control system for vehicle comprising:

battery voltage monitor means for monitoring a battery voltage charged from a vehicle generator driven by means of an internal combustion engine;

maximum engine speed limiting means for imposing a limit on a maximum engine speed of said internal combustion engine using a command signal; and

secondary failure avoiding control means for feeding said command signal to said maximum engine speed limiting means, suppressing abnormality in battery voltage by maintaining a voltage generated by said vehicle generator at a normal value, and avoiding a secondary failure due to abnormality in battery voltage in the case where it is determined that said battery voltage exceeds a predetermined value.

17. A method for controlling a vehicle internal combustion engine includes steps of:

detecting a voltage generated by a vehicle generator driven by means of an internal combustion engine and a battery voltage charged from said vehicle generator;

operating maximum engine speed limiting means for imposing a limit on a maximum engine speed of said internal combustion engine to impose a limit on a revolving speed of said vehicle generator when said generated voltage and/or said battery voltage exceeds a predetermined voltage; and

maintaining said generated voltage and said battery voltage at a normal value by turning ON or OFF an electric load that receives a power supply from said battery to avoid a secondary failure due to abnormality in voltage.