US 4,286,560 A · Method and apparatus for controlling an ignition timing

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.

Claims9

Dependent claims

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.

8 more elements

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.

9 more elements

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.

6 more elements

Dependencies are inferred from the claim text.

Method and apparatus for controlling an ignition timing

Life of this patent

Method and apparatus for controlling an ignition timing

Life of this patent

Abstract

Claims9