Apparatus and method for controlling ignition timing for internal combustion engine

• US 4,799,469 A
• Filed: 01/05/1987
• Issued: 01/24/1989
• Est. Priority Date: 01/08/1986
• Status: Expired due to Term

• Current Assignee: Hitachi, Ltd.
• Original Assignee: Hitachi, Ltd.
• Inventors: Nagano, Masami, Manaka, Toshio, Atago, Takeshi
• Primary Examiner(s): Nelli, Raymond A.
• Application Number:
  US07/000,446
• Time in Patent Office: 750 Days
• Field of Search: 123/418, 123/406, 123/422, 123/423, 123/419, 123/436
• US Class Current: 477/111
• CPC Class Codes: F02P 5/045 combined with electronic control of other engine functions, e.g. fuel injection in general F02D37/02
• CPC Class Codes: F02P 5/1504 with particular means during a transient phase, e.g. acceleration, deceleration, gear change during starting F02P5/1506
• CPC Class Codes: F02P 5/151 with means for compensating the variation of the characteristics of the engine or of a sensor, e.g. by ageing
• CPC Class Codes: F02P 5/1514 with means for optimising the use of registers or of memories, e.g. interpolation
• CPC Class Codes: Y02T 10/40 Engine management systems

Abstract

The ignition timing is controlled in that a change in engine speed is detected from a differentiated value dN/dt, and when dN/dt is larger than a predetermined value and when a value of dN/dt is positive, the ignition timing is retarded by a predetermined value from a fundamental ignition timing, and further, when dN/dt is larger than the predetermined value and when the value of dN/dt is negative, the ignition timing is advanced by the predetermined value from the fundamental ignition timing.

Claims

1. A method for controlling ignition timing comprising the steps of:

determining a fundamental ignition timing amount based on an engine operating condition;

determining a direction of change in an engine speed which indicates whether the speed is increasing or decreasing;

determining a correction ignition timing amount based on the direction of change in the engine speed, said correction ignition timing amount having a value which is substantially ineffective at an engine speed in the vicinity of a point at which the direction of change of the engine speed is inverted and is a maximum value at a time point at which the changing rate of the engine speed is maximum; and

determining ignition timing by adding or subtracting said correction ignition timing amount to or from said fundamental ignition timing amount.

2. An ignition timing control apparatus for an internal combustion engine, comprising:

(a) engine speed detecting means for producing an engine speed signal;

(b) fundamental ignition timing determining means for producing a fundamental ignition timing value on the basis of an operating condition of said engine;

(c) change rate discriminating means for differentiating said engine speed signal and for determining if the rate of change of engine speed is larger than a predetermined value;

(d) correction ignition timing means for producing a correction ignition timing value when said rate of change of engine speed is larger than said predetermined value as indicated by said change rate discriminating means;

(e) change direction determining means for determining the direction of change of said engine speed which indicates whether the speed is increasing or decreasing; and

(f) final ignition timing determining means for producing a final ignition timing signal corresponding to said fundamental ignition timing valve when said rate of change of engine speed is not larger than said predetermined value and corresponding to said fundamental ignition timing value corrected by said correction ignition timing value in accordance with the direction of change of engine speed when said rate of change of engine speed is larger than said predetermined value, including;

means for correcting said fundamental ignition timing value by adding said correction ignition timing value thereto when said engine speed is changing in the decreasing direction and by subtracting said correction ignition timing value therefrom when said engine speed is changing in the increasing direction, wherein said correction ignition timing means includes means for counting sequential ignition time periods following detection of a change in the direction of change of engine speed, and means responsive to said counting means for producing correction ignition timing values in a predetermined number of successive ones of said sequential ignition time periods beginning with one of said ignition time periods other than the first ignition time period following detection of a change in the direction of change of engine speed.

3. An ignition timing control apparatus according to claim 2, wherein said correction ignition timing values vary in magnitude during said successive ones of said sequential ignition time periods according to a predetermined pattern.

4. An ignition timing control apparatus according to claim 2, wherein said predetermined number of successive ones of said ignition time periods is different for different ranges of engine speed.

5. An ignition timing control apparatus according to claim 2, further including condition detecting means for detecting when respective transmission gears are engaged, and wherein said correction igniting timing means includes correction amount changing means responsive to said condition detecting means for changing the number of sequential ignition time periods during which the correction ignition timing values are produced for respectively different transmission gears detected by said condition detecting means.

6. An ignition timing control apparatus for an internal combustion engine, comprising:

(a) engine speed detecting means for producing an engine speed signal;

(b) fundamental ignition timing determining means for producing a fundamental ignition timing value on the basis of an operating condition of said engine;

(c) change rate discriminating means for differentiating said engine speed signal and for determining if the rate of change of engine speed is larger than a predetermined value;

(d) correction ignition timing means for producing a correction ignition timing value when said rate of change of engine speed is larger than said predetermined value as indicated by said change rate discriminating means;

(e) change direction determining means for determining the direction of change of said engine speed which indicates whether said speed is increasing or decreasing; and

(f) final ignition timing determining means for producing a final ignition timing signal corresponding to said fundamental ignition timing value when said rate of change of engine speed is not larger than said predetermined value and corresponding to said fundamental ignition timing value corrected by said correction ignition timing value in accordance with the direction of change of engine speed when said rate of change of engine speed is larger than said predetermined value, including;

means for correcting said fundamental ignition timing value by adding said correction ignition timing value thereto when said engine speed is changing in the decreasing direction and by subtracting said correction ignition timing value therefrom when said engine speed is changing in the increasing direction, further including condition detecting means for detecting when respective transmission gears are engaged and when the transmission is in a neutral condition, and correction amount changing means for changing the magnitude of said correction ignition timing values so that larger values are provided when said transmission is in a neutral condition as detected by said condition detecting means.

7. An ignition timing control apparatus for an internal combustion engine, comprising:

(a) engine speed detecting means for producing an engine speed signal;

(b) fundamental ignition timing determining means for producing a fundamental ignition timing value on the basis of an operating condition of said engine;

(c) change rate discriminating means for differentiating said engine speed signal and for determining if the rate of change of engine speed is larger than a predetermined value;

(d) correction ignition timing means for producing a correction ignition timing value when said rate of change of engine speed is larger than said predetermined value as indicated by said change rate discriminating means;

(e) change direction determining means for determining the direction of change of said engine speed which indicates whether said speed is increasing or decreasing; and

(f) final ignition timing determining means for producing a final ignition timing signal corresponding to said fundamental ignition timing value when said rate of change of engine speed is not larger than said predetermined value and corresponding to said fundamental ignition timing value corrected by said correction ignition timing value in accordance with the direction of change of engine speed when said rate of change of engine speed is larger than said predetermined value, including;

means for correcting said fundamental ignition timing value by adding said correction ignition timing value thereto when said engine speed is changing in the decreasing direction and by subtracting said correction ignition timing value therefrom when said engine speed is changing in the increasing direction wherein said correction ignition timing means includes means responsive to said change rate discriminating means for producing correction ignition timing values having a magnitude proportional to the rate of change of engine speed.

8. An ignition timing control apparatus according to claim 7, further comprising speed range detecting means for detecting when the engine speed is in a predetermined range between an idling speed and a first predetermined engine speed, and wherein said correction ignition timing means is responsive to said range detecting means to produce correction ignition timing values only when the engine speed is in said predetermined range.

9. An ignition timing control apparatus according to claim 7, further including speed range detecting means for detecting when the engine speed is in a predetermined range and load detecting means for detecting engine load, and wherein said correction ignition timing means is responsive to said range detecting means and said load detecting means to produce correction ignition timing values only when the engine speed is in said predetermined range and said engine load is smaller than a predetermined value.