Method and apparatus for controlling an ignition timing

• US 4,286,560 A
• Filed: 03/26/1980
• Issued: 09/01/1981
• Est. Priority Date: 03/28/1979
• Status: Expired due to Term

• Current Assignee: Nippondenso Co., Ltd. (DENSO Corporation)
• Original Assignee: Nippondenso Co., Ltd. (DENSO Corporation)
• Inventors: Kobayashi, Akio, Sagisaka, Yasuo, Kondo, Toshio
• Primary Examiner(s): Cox, Ronald B.
• Application Number:
  US06/134,335
• Time in Patent Office: 524 Days
• Field of Search: 123/117 R, 123/117 D, 123/32 EB, 123/415, 123/416, 123/417, 123/480, 123/486, 123/489
• US Class Current: 123/406.23
• CPC Class Codes: F02P 5/1455 by using a second control of the closed loop type dependent on pinking F02P5/152
• CPC Class Codes: Y02T 10/40 Engine management systems

Abstract

An apparatus for controlling an ignition timing of an internal combustion engine for each ignition cycle. The apparatus fetches digital signals representing an intake pipe negative pressure and the number of revolutions of the internal combustion engine, and a digital signal representing a fuel injection time, and computes a basic timing of ignition spark by using the intake pipe negative pressure and the number of revolutions. When the intake pipe negative pressure and the number of revolutions, both being sensed currently, have ratios of changes falling within given values, compared with those sensed precedingly, correction values read out from a memory device on the basis of the intake pipe negative pressure and the number of revolutions are corrected so as to reduce the fuel injection time in accordance with the result of a comparison of the fuel injection time of the fuel injection currently performed with that of the fuel injection precedingly performed. An ignition timing is determined by correcting the basic ignition timing depending on the corrected correction value of the ignition timing. The corrected correction value is loaded into the memory device in place of the correction value before correction. When the intake pipe negative pressure and the number of revolutions, both being sensed currently, changes with ratio which falls out of fixed values, compared with those sensed precedingly, the basic ignition timing is corrected by the correction value of ignition timing read out on the basis of the intake pipe negative pressure and the number of revolutions, without correcting by the fuel injection time, thereby to determine an ignition timing. An ignition signal is applied to an internal combustion engine igniting device in accordance with the ignition timing determined.

Claims

1. An apparatus for controlling a timing of ignition spark to be supplied to ignite a mixture of air and fuel supplied to an internal combustion engine comprising:

means for sensing operating conditions of said engine;

means for sensing an amount of fuel supplied to said engine;

means for storing, in a nonvolatile manner, a group of correction values in respective addressable storage locations;

means for computing a timing of ignition spark, so that a fuel efficiency relative to the output torque of said engine is maximized, said computing means including;

means for determining a basic timing of an ignition spark in accordance with said operating conditions sensed currently;

means for discriminating whether said operating conditions sensed currently are close to or apart from said operating conditions sensed precedingly, said discriminating means providing first and second outputs respectively indicating that the former is close to or apart from the latter;

means for discriminating, in response to said first output, whether said amount of fuel sensed currently in larger or less than said amount of fuel sensed precedingly,

means for determining a new correction value in accordance with the discrimination result of said latter discriminating means and with one of said correction values stored in one of said storage locations addressed in correspondence with said operating conditions sensed currently, said new correction value being more effective to maximize said fuel efficiency than said one of said correction values is and being stored in said one of said storage locations in place of said one of said correction values, and

means for correcting said basic timing of ignition spark by said new correction value, said correcting means correcting the same by another one of said correction values stored in another one of said storage locations addressed in correspondence with said operating conditions sensed currently in response to said second output; and

means for supplying said engine with an ignition spark at said corrected timing of ignition spark.

2. An apparatus for controlling a timing of ignition spark to be supplied to ignite a mixture of air and fuel supplied to an internal combustion engine comprising:

means for sensing operating conditions of said engine;

means for sensing amount of fuel supplied to said engine;

means for storing, in a non-volatile manner, a group of correction values in respective addressable storage locations;

means for computing a timing of ignition spark so that a fuel efficiency relative to the output torque of said engine is maximized, said computing means including;

means for determining a basic timing of ignition spark in accordance with said operating conditions sensed currently,

means for discriminating whether said operating conditions sensed currently is close to or apart from said operating conditions sensed precedingly, said discriminating means providing first and second outputs respectively indicating that the former is close to or apart from the latter,

means for comparing, in response to said first output, an actual timing of ignition spark supplied to said engine currently with an actual timing of ignition spark supplied to said engine precedingly,

means for comparing, in response to said first output, said amount of fuel sensed currently with said amount of fuel sensed precedingly,

means for determining a new correction value in accordance with the comparison results of said two comparing means and with one of said correction values stored in one of said storage locations addressed in correspondence with said operating conditions sensed currently, said new correction value being more effective to maximize said fuel efficiency than said one of said correction values is and being stored in said one of storage locations in place of said one of said correction values, and

means for correcting said basic timing of ignition spark by said new correction value, said correcting means correcting the same by another one of said correction values stored in another one of storage locations addressed in correspondence with said operating conditions sensed currently in response to said second output; and

means for supplying said engine with an ignition spark at said corrected timing of ignition spark.

3. A method for controlling a timing of an ignition spark to be supplied to ignite a mixture of air and fuel supplied to an internal combustion engine comprising the steps of:

sensing the number of revolutions of the engine and an intake air negative pressure;

computing the basic timing of an ignition spark by using the number of revolutions and the intake air negative pressure;

sensing an amount of fuel supplied to the engine when the number of revolutions sensed and the intake air negative pressure sensed is close to those sensed in the preceding ignition cycle;

discriminating or judging whether said amount of fuel sensed currently is larger or less than said amount of fuel sensed precedingly;

reading out the correction values of the ignition timing for the number of revolutions and the intake air negative pressure stored in a non-volatile memory device, correcting the ignition timing correction values so as to maximize the fuel efficiency on the basis of the judgement of the amount of fuel supplied, and storing the corrected correction values of the ignition timing into the memory in place of the correction value before it is corrected;

determining an ignition timing by correcting the basic ignition timing on the basis of the corrected ignition correction value of the ignition timing;

determining an ignition timing by correcting the basic ignition timing by using the uncorrected correcting value of ignition timing when the number of revolutions sensed currently and the intake air negative pressure sensed currently are apart from those sensed precedingly; and

transferring an ignition signal to the internal combustion ignition device in accordance with the ignition timing determined.

4. The ignition timing control method according to claim 3, further comprising the step of comparing an actual timing of ignition spark sensed currently with an actual timing of ignition spark sensed precedingly, when the number of revolutions currently sensed and the intake air negative pressure currently sensed are close to those precedingly sensed.

5. An apparatus for controlling ignition spark timing for an internal combustion engine comprising:

means for sensing operating conditions of said engine;

means for sensing an amount of fuel supplied to said engine;

means for determining ignition spark timing so that a fuel efficiency relative to the output torque of said engine is maximized, said timing determining means including;

means for determining a timing of an ignition spark in accordance with said operating conditions sensed currently,

means for discriminating whether said operating conditions sensed currently are close to or apart from said operating conditions sensed precedingly, said discriminating means providing an output indicating that the former is close to the latter, and

means responsive to said output, for step-wise altering, during each engine cycle, said timing to minimize the fuel supplied to said engine; and

means for supplying said engine with an ignition spark at said altered timing.

6. An apparatus for controlling ignition spark timing for an internal combustion engine comprising:

means for sensing operating conditions of said engine;

means for sensing an amount of fuel supplied to said engine;

means for determining ignition spark timing so that a fuel efficiency relative to the output torque of said engine is maximized, said timing determining means including;

means for determining a basic timing of an ignition spark in accordance with said operating conditions sensed currently,

means for determining a correction value in accordance with said operating condition sensed currently,

means for discriminating whether said operating conditions sensed currently are close to or apart from said operating conditions sensed precedingly, said discriminating means providing first and second outputs respectively indicating that the former is close to and apart from the latter,

means for discriminating, in response to said first output, whether said amount of fuel sensed currently is greater or less than said amount of fuel sensed precedingly,

means for revising a correction value corresponding to the operating conditions currently sensed in accordance with the discriminating result of said latter discriminating means, said revised correction value being more effective to maximize said fuel efficiency than said correction value, and

means for correcting said basic timing of ignition spark by said revised correction value said correcting means correcting the same by another one of said correction values in correspondence with said operating conditions sensed currently in response to said second output; and

means for supplying said engine with an ignition spark at said corrected timing of ignition spark.

7. An apparatus for controlling ignition spark timing for an internal combustion engine comprising:

means for sensing operating conditions of said engine;

means for sensing an amount of fuel supplied to said engine;

means for determining ignition spark timing so that a fuel efficiency relative to the output torque of said engine is maximized, said timing determining means including;

means for determining a basic timing of an ignition spark in accordance with said operating conditions sensed currently,

means for determining a correction value in accordance with said operating conditions sensed currently,

means for discriminating whether said operating conditions sensed currently are close to or far apart from said operating conditions sensed precedingly, said discriminating means providing first and second outputs respectively indicating that the former is close to or apart from the latter,

means for comparing, in response to said first output, an actual timing of ignition spark supplied to said engine currently with an actual timing of ignition spark supplied to said engine precedingly,

means for comparing, in response to said first output, an amount of fuel sensed currently with said amount of fuel sensed precedingly,

means for revising a correction value corresponding to said operating conditions sensed currently in accordance with the comparison results of said two comparing means, said revised correction value being more effective to maximize said fuel efficiency than said correction value, and

means for correcting said basic timing of spark ignition by said revised correction value, said correcting means correcting the same by another correction value in correspondence with said operating conditions sensed currently in response to said second output; and

means for supplying an engine with an ignition spark at said corrected timing of spark ignition.

8. A method for controlling ignition spark timing for an internal combustion engine comprising the steps of:

sensing operating conditions of said engine;

sensing an amount of fuel supplied to said engine;

determining a timing of an ignition spark in accordance with said operating conditions sensed currently;

discriminating whether said operating conditions sensed currently are close to or apart from said operating conditions sensed precedingly, said discriminating step providing an output indicating that the former is close to the latter;

step-wise altering said timing during each engine cycle in response to said output to minimize the fuel supplied to said engine; and

supplying said engine with an ignition spark at said altered timing.

9. A method for controlling ignition spark timing for an internal combustion engine comprising the steps of:

sensing operation conditions of said engine;

sensing an amount of fuel supplied to said engine;

determining a basic timing of an ignition spark in accordance with said operating conditions sensed currently;

determining a correction value in accordance with said operating conditions sensed currently;

discriminating whether said operating conditions sensed currently are close to or apart from said operating conditions sensed precedingly, said discriminating step providing first and second outputs respectively indicating that the former is close to and apart from the latter;

discriminating, in response to said first output, whether said amount of fuel sensed currently is greater or less than said amount of fuel sensed precedingly;

revising a correction value in accordance with the discrimination results of said latter discriminating step, said revised correction value being more effective to maximize said fuel efficiency than said correction value;

correcting said basic timing of ignition spark by said revised correction value in response to said first output;

correcting said basic timing of ignition spark by a correction value corresponding to said operating conditions currently sensed in response to said second output; and

supplying said engine with an ignition spark at said correction timing of ignition spark.