System and method for preventing spark-on-make in an internal combustion engine using manifold pressure

• US 6,247,465 B1
• Filed: 02/11/2000
• Issued: 06/19/2001
• Est. Priority Date: 02/11/2000
• Status: Expired due to Fees

• Current Assignee: Delphi Technologies, Inc. (BorgWarner Incorporated)
• Original Assignee: Delphi Technologies, Inc. (BorgWarner Incorporated)
• Inventors: Sprunger, Douglas Lynn
• Primary Examiner(s): ARGENBRIGHT, TONY MICHAEL
• Application Number:
  US09/502,751
• Time in Patent Office: 494 Days
• Field of Search: 123/609, 123/610, 123/625, 123/630, 123/644, 123/645
• US Class Current: 123/609
• CPC Class Codes: F02D 2200/0406 Intake manifold pressure
• CPC Class Codes: F02P 11/02 Preventing damage to engines or engine-driven gearing
• CPC Class Codes: F02P 3/0453 Opening or closing the primary coil circuit with semiconductor devices

Abstract

A system is provided for preventing spark-on-make in an internal combustion engine, using manifold pressure information. The system includes a pressure sensor and a controller. The pressure sensor is adapted to detect pressure in an intake manifold and provide an output signal indicative of that pressure. The controller is at least indirectly connected to the pressure sensor and is adapted to delay initiation of ignition dwell in a coil by a period of time sufficient to avoid spark-on-make, in response to the output signal from the sensor. Preferably, the pressure sensor is a manifold absolute pressure (MAP) sensor. The controller preferably is implemented by suitably programming or otherwise configuring an electronic engine control unit (ECU). Also provided is a method for preventing spark-on-make in an internal combustion engine.

Claims

1. A system for preventing spark-on-make in an internal combustion engine, comprising:

a pressure sensor adapted to detect pressure in an intake manifold and provide an output signal indicative of that pressure; and

a controller at least indirectly connected to the pressure sensor and adapted to delay initiation of ignition dwell in a coil by a period of time sufficient to avoid spark-on-make, in response to the output signal from the sensor.

2. The system of claim 1, wherein said pressure sensor is a manifold absolute pressure (MAP) sensor.

3. The system of claim 1, wherein said controller is adapted to provide said delay in such a way that, when pressure increases according to the output signal, the magnitude of the delay decreases.

4. The system of claim 1, wherein said controller is adapted to delay initiation of ignition dwell in an ignition coil by a period of time sufficient to avoid spark-on-make by a predetermined safety margin, in response to the output signal from the sensor.

5. The system of claim 4, wherein said predetermined safety margin corresponds to sufficient delay so that a make voltage developed across a secondary winding of the ignition coil, upon commencement of dwell, has a predetermined safety voltage level that is less than a spark demand voltage of a spark plug connected to said ignition coil, at said pressure.

6. The system of claim 4, wherein said predetermined safety margin corresponds to sufficient delay so that a make voltage developed across a secondary winding of the ignition coil, upon commencement of dwell, has a predetermined safety voltage level that is less than or equal to about 80% of a spark demand voltage of a spark plug connected to the ignition coil, at said pressure.

7. The system of claim 4, wherein said predetermined safety margin corresponds to sufficient delay so that a make voltage developed across a secondary winding of the ignition coil, upon commencement of dwell, is about 80% of a spark demand voltage of a spark plug connected to the ignition coil, at said pressure.

8. The system of claim 4, wherein said controller is adapted to calculate, based on a present value of a supply voltage, a make voltage level that would be developed across a secondary winding of the ignition coil upon connection of the supply voltage to a primary winding of the ignition coil;

wherein said controller is associated with a memory, said memory containing a plurality of tables, each table being associated with a respective value or range of values of said pressure and containing a plurality of safety voltage maximum levels, each safety voltage maximum level being correlated in each said table to an earliest safe crank angle value at which dwell can be commenced without causing the make voltage to exceed the correlated safety voltage maximum level, each safety voltage maximum level in each table being less than the spark demand voltage by said predetermined safety margin at a respective pressure and at the earliest safe crank angle correlated to that safety voltage maximum level;

wherein said controller is adapted to access, based on said output signal, one of said tables that corresponds to the present value of said pressure, and to access, within said one of the tables and based on said make voltage level calculated by the controller, the earliest safe crank angle value at which dwell can be commenced without causing the make voltage to exceed the correlated safety voltage maximum level; and

wherein said controller is adapted to prevent initiation of dwell until the crank angle indicated by the earliest safe crank angle value selected by accessing said one of the tables using the make voltage level, is reached.

9. The system of claim 8, wherein said memory is internal to the controller.

10. The system of claim 8, wherein said controller, when accessing the earliest safe crank angle value, is adapted to select from among the safety voltage maximum levels within said one of the tables, a particular one that is greater than and closest to said make voltage level calculated by the controller.

11. The system of claim 8, wherein said controller is adapted to calculate said make voltage level in a non-arithmetic manner.

12. The system of claim 8, wherein said controller is adapted to calculate said make voltage level in an arithmetic manner.

13. The system of claim 1, wherein said controller is adapted to calculate, based on a present value of a supply voltage, a make voltage level that would be developed across a secondary winding of the ignition coil upon connection of the supply voltage to a primary winding of the ignition coil, said controller being adapted to provide said delay in a manner dependent upon both said make voltage level and said output signal from the pressure sensor.

14. A method for preventing spark-on-make in an internal combustion engine, said method comprising the steps of:

detecting pressure in an intake manifold;

providing an output signal indicative of that pressure; and

delaying initiation of ignition dwell in an ignition coil by a period of time sufficient to avoid spark-on-make, in response to the output signal.

15. The method of claim 14, wherein said pressure that is detected is a manifold absolute pressure (MAP).

16. The method of claim 14, wherein said step of delaying is performed in such a way that, when pressure increases according to the output signal, the magnitude of the delay decreases.

17. The method of claim 14, wherein said step of delaying is performed by a period of time sufficient to avoid spark-on-make by a predetermined safety margin, in response to the output signal.

18. The method of claim 17, wherein said predetermined safety margin corresponds to sufficient delay so that a make voltage developed across a secondary winding of the ignition coil, upon commencement of dwell, has a predetermined safety voltage level that is less than a spark demand voltage of a spark plug connected to said ignition coil, at said pressure.

19. The method of claim 17, wherein said predetermined safety margin corresponds to sufficient delay so that a make voltage developed across a secondary winding of the ignition coil, upon commencement of dwell, has a predetermined safety voltage level that is less than or equal to about 80% of a spark demand voltage of a spark plug connected to the ignition coil, at said pressure.

20. The method of claim 17, wherein said predetermined safety margin corresponds to sufficient delay so that a make voltage developed across a secondary winding of the ignition coil, upon commencement of dwell, is about 80% of a spark demand voltage of a spark plug connected to the ignition coil, at said pressure.

21. The method of claim 17, wherein said step of delaying includes:

calculating, based on a present value of a supply voltage, a make voltage level that would be developed across a secondary winding of the ignition coil upon connection of the supply voltage to a primary winding of the ignition coil;

providing a plurality of tables, each table being associated with a respective value or range of values of said pressure and containing a plurality of safety voltage maximum levels, each safety voltage maximum level being correlated in each said table to an earliest safe crank angle value at which dwell can be commenced without causing the make voltage to exceed the correlated safety voltage maximum level, each safety voltage maximum level in each table being less than the spark demand voltage by said predetermined safety margin at a respective pressure and at the earliest safe crank angle correlated to that safety voltage maximum level;

accessing, based on said output signal, one of said tables that corresponds to the present value of said pressure;

accessing, within said one of the tables and based on said make voltage level, the earliest safe crank angle value at which dwell can be commenced without causing the make voltage to exceed the correlated safety voltage maximum level; and

preventing initiation of dwell until the crank angle indicated by the earliest safe crank angle value selected by accessing said one of the tables using the make voltage level, is reached.

22. The method of claim 21, wherein said tables are stored in an electronic memory, and wherein the steps of the method are performed by an electronic engine control unit.

23. The method of claim 21, wherein said step of accessing the earliest safe crank angle value includes the step of selecting from among the safety voltage maximum levels within said one of the tables, a particular one that is greater than and closest to said make voltage level.

24. The method of claim 21, wherein said step of calculating the make voltage level is performed in a non-arithmetic manner.

25. The method of claim 21, wherein said step of calculating the make voltage level is performed in an arithmetic manner.

26. The method of claim 14, wherein said step of delaying includes:

calculating, based on a present value of a supply voltage, a make voltage level that would be developed across a secondary winding of the ignition coil upon connection of the supply voltage to a primary winding of the ignition coil; and

delaying initiation of ignition dwell in an ignition coil by a period of time sufficient to avoid spark-on-make, in response to the output signal and the make voltage level.

27. A system for preventing spark-on-make in an internal combustion engine, said system comprising:

means for detecting pressure in an intake manifold and providing an output signal indicative of that pressure; and

means for delaying initiation of ignition dwell of an ignition coil by a period of time sufficient to avoid spark-on-make, in response to the output signal.

28. The system of claim 27, wherein said means for detecting pressure is a manifold absolute pressure (MAP) sensor.