Spark ignition timing system for internal combustion engine with feature of supression of jerking during engine acceleration

Claim 2

A spark ignition timing control system for an internal combustion engine comprising: sensor means monitoring preselected parameters for producing a sensor signal; first means for deriving a spark ignition timing on the basis of data contained in said sensor signal; second means for detecting an engine acceleration demand for producing an accelerating condition indicative signal; and third means, responsive to said accelerating condition indicative signal, for modifying said spark ignition timing derived by said first means after expiration of a first predetermined period of time of occurence of said accelerating condition indicative signal, in such a manner that the spark ignition timing is advanced and retarded for suppressing cycle-to-cycle fluctuation of engine speed and for smoothly increasing engine speed.

Claim 3

A spark ignition timing control system for an internal combustion engine comprising: sensor means monitoring preselected parameters for producing sensor signals including engine speed indicative data and engine load indicative data; first means for deriving a spark ignition timing on the basis of data contained in said sensor signal; second means for monitoring an engine load indicative data for detecting an engine acceleration demand for producing an accelerating condition indicative signal; and third means, responsive to said accelerating condition indicative signal, for modifying said spark ignition timing derived by said first means in such a manner that spark ignition timing is advanced and retarded for suppressing cycle-to-cycle fluctuation of engine speed and for smoothly increasing engine speed during a predetermined acceleration transition period.

Claim 4

A spark ignition timing control system for an internal combustion engine comprising: sensor means monitoring preselected parameters for producing sensor signals including engine speed indicative data and engine load indicative data; first means for deriving a spark ignition timing on the basis of data contained in said sensor signal; second means for monitoring an engine load indicative data for detecting an engine acceleration demand for producing an accelerating condition indicative signal; and third means, responsive to said accelerating condition indicative signal, for modifying said spark ignition timing derived by said first means in such a manner that spark ignition timing is advanced and retarded for suppressing cycle-to-cycle fluctuation of engine speed and for smoothly increasing engine speed during a predetermined acceleration transition period.

Claim 5

A spark ignition timing control system as set forth in claim 1 or 2, wherein said third means is active for a predetermined acceleration transition period of time which is longer than said first predetermined period of time.

Claim 6

A spark ignition timing control system as set forth in claim 3, wherein said third means advances said spark ignition timing in response to engine speed fluctuation in the decelerating direction and retards said spark ignition timing in response to engine speed fluctuation in the accelerating direction.

Claim 7

A spark ignition timing control system as set forth in claim 4, wherein said third means varies the magnitude of advancing and retarding of the spark ignition timing in response to engine speed fluctuation according to an engine speed.

Claim 8

A spark ignition timing control system as set forth in claim 5, wherein said third means derives said magnitude of advancing or retarding of the spark ignition timing as a function of the engine speed.

Claim 9

A spark ignition timing control system as set forth one of the claims 1 to 6, wherein said third means is responsive to said accelerating condition indicative signal to retard spark ignition timing by a predetermined magnitude and subsequently advance the spark ignition timing by a given magnitude which is substantially smaller than said predetermined retarding magnitude, during said first predetermined period.

Claim 10

A spark ignition timing control system as set forth in claim 7, wherein said third means advances said spark ignition timing in response to engine speed fluctuation in the decelerating direction and retards said spark ignition timing in response to engine speed fluctuation in the accelerating direction, during a second predetermined period of time following said first predetermined period in said acceleration transition period.

Claim 11

A spark ignition timing control system as set forth in one of the claims 1 to 8, wherein said second means is associated with a throttle angle sensor which monitors a throttle valve angular position to produce a throttle angle signal, for detecting increase of throttle valve angular displacement to increase throttle valve open angle in a ratio greater than a predetermined value for producing said accelerating condition indicative signal.

Claim 12

A spark ignition timing control system as set forth in claims 2 to 9, wherein said sensor means comprises a crank angle sensor for producing a crank reference signal at every predetermined angular position of a crankshaft, and said first means derives said engine speed on the basis of the interval between subsequently occurring crank reference signals.

Claim 13

A spark ignition timing control system as set forth in one of the claims 1 to 10, wherein said third means is responsive to said accelerating condition indicative signal to retard spark ignition timing by a predetermined magnitude and to subsequently advance the spark ignition timing by a given magnitude which is sub­stantially smaller than said predetermined retarding magnitude, during said first predetermined period.

Claim 14

A spark ignition timing control system as set forth in one of the claims 1 to 11, wherein said third means is active after expiration of a first predetermined period from occurrence of said accelera­tion indicative signal, to modify said spark ignition timing.

Claim 15

A spark ignition timing control system as set forth one of the claims 1 to 12, wherein said third means is active after expiration of a first predetermined period from occurrence of said accelera­tion indicative signal, to modify said spark ignition timing.

Claim 16

A spark ignition timing control system as set forth in one of the claims 1 to 13, wherein said second means is associated with a throttle angle sensor as a sensor for monitoring engine load indicative parameter, which monitors a throttle valve angular position to produce a throttle angle signal, for detec­ting increase of throttle valve angular displacement to increase throttle valve open angle in a ratio greater than a predetermined value for producing said accelerating condition indicative signal.