US4380989A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Ignition system for internal combustion engine
Assignee: Denso Corp
•
Filing: 1980-11-19
•
Granted: 1983-04-26
•
Expires: 2000-11-19
Abstract
Abstract An ignition system for an internal combustion engine in which the primary voltage applied across the primary winding of the ignition coil is detected together with the secondary current flowing through the secondary winding of the ignition coil, and the electrical characteristic of the secondary circuit of the ignition coil supplying the arc energy is calculated on the basis of the detected signals thereby controlling the primary current supplied to the primary winding of the ignition coil on the basis of the result of calculation, so that the secondary circuit of the ignition coil can exhibit the desired electrical characteristic for supplying the arc energy of desired level.
Inventors
- 👤 Iwao Takaki
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 14:49
CPC Classifications
F; F02; F02P; F02P15/00; F02P15/10; F02P17/00; F02P17/10; F02P3/00; F02P3/02; F02P3/04; F02P3/045; F02P3/0453; F02P3/0456; F02P3/05; F02P3/051; F02P3/053; F02P17/12
Claims Analysis
Total Claims: 17
Claim 1
Independent Claim
227 words
An ignition system for an internal combustion engine comprising an ignition signal generator generating an ignition signal in synchronism with the rotation of the engine, a power transistor unit turned on-off in response to the ignition signal generated from said ignition signal generator, an ignition coil including a primary winding and a secondary winding electrically isolated from each other, the primary winding being connected to said power transistor unit turned on-off to interrupt the primary current supplied to the primary winding of said ignition coil, a spark plug connected to one end of the secondary winding of said ignition coil, a secondary current detecting resistor connected between the other end of the secondary winding of said ignition coil and an earth potential point for detecting the secondary current flowing through the secondary winding of said ignition coil, a calculating circuit receiving both of the secondary current detected by said secondary current detecting resistor and the primary voltage detected by a primary voltage resistor connected to a grounded side end of the primary winding of said ignition coil as its input signals for calculating, on the basis of these input signals, an ignition control value representing the characteristics of the secondary electrical circuit of said ignition coil, and means responsive to the output signal from said calculating circuit for controlling the high voltage applied across said spark plug.
Claim 2
Dependent Claim
227 words
An ignition system for an internal combustion engine comprising an ignition signal generator generating an ignition signal in synchronism with the rotation of the engine, a power transistor unit turned on-off in response to the ignition signal generated from said ignition signal generator, an ignition coil including a primary winding and a secondary winding electrically isolated from each other, the primary winding being connected to said power transistor unit turned on-off to interrupt the primary current supplied to the primary winding of said ignition coil, a spark plug connected to one end of the secondary winding of said ignition coil, a secondary current detecting resistor connected between the other end of the secondary winding of said ignition coil and an earth potential point for detecting the secondary current flowing through the secondary winding of said ignition coil, a calculating circuit receiving both of the secondary current detected by said secondary current detecting resistor and the primary voltage detected by a primary voltage resistor connected to a grounded side end of the primary winding of said ignition coil as its input signals for calculating, on the basis of these input signals, an ignition control value representing the characteristics of the secondary electrical circuit of said ignition coil, and means responsive to the output signal from said calculating circuit for controlling the high voltage applied across said spark plug.
Claim 3
Dependent Claim
23 words
An ignition system for an internal combustion engine as claimed in claim 1, wherein said control means includes a primary current control circuit.
Claim 4
Dependent Claim
117 words
An ignition system for an internal combustion engine as claimed in claim 2, wherein said primary current control circuit includes a primary current detecting resistor connected to the primary winding of said ignition coil for detecting the primary current supplied to the primary winding of said ignition coil, a current value control circuit controlling the peak value of the primary current detected by said primary current detecting resistor so as to limit the peak value to a predetermined setting, and a constant-current value compensating signal output circuit compensating the setting of said current value control circuit so that the characteristic of the secondary electrical circuit calculated by said calculating circuit can be maintained at a predetermined setting.
Claim 5
Dependent Claim
35 words
An ignition system for an internal combustion engine as claimed in claim 3, wherein the setting of said constant-current value compensating signal output circuit is variable depending on at least one of the engine parameters.
Claim 6
Dependent Claim
82 words
An ignition system for an internal combustion engine as claimed in claim 2, wherein said primary current control circuit includes a dwell angle control circuit controlling the dwell angle of said power transistor unit in response to the ignition signal generated from said ignition signal generator, and a current-supply duration compensating signal output circuit compensating the setting of said dwell angle control circuit so that the characteristic of the secondary electrical circuit calculated by said calculating circuit can provide a predetermined value.
Claim 7
Dependent Claim
38 words
An ignition system for an internal combustion engine as claimed in claim 5, wherein the duration compensating output signal from said current-supply duration compensating signal output circuit is variable depending on at least one of the engine parameters.
Claim 8
Dependent Claim
20 words
An ignition system for an internal combustion engine as claimed in claim 1 wherein said calculating circuit includes a multiplier.
Claim 9
Dependent Claim
138 words
An ignition system in accordance with claim 1, wherein said calculating circuit comprises a secondary resistance calculating circuit receiving the secondary current detected by said secondary current detecting resistor and the primary voltage across the primary winding of said ignition coil as its input signals for calculating, on the basis of these input signals, the value of the secondary resistance of said ignition coil, a comparing circuit comparing the value of the secondary resistance calculated by said secondary resistance calculating circuit with a predetermined value representing the critical point of accumulation of soot on the electrodes of said spark plug and generating a sooting indicative output when the latter value exceeds the former value, and sooting removing means acting to remove the accumulating soot in response to the appearance of the sooting indicative output from said comparing circuit.
Claim 10
Dependent Claim
22 words
An ignition system for an internal combustion engine as claimed in claim 8, wherein said secondary resistance calculating circuit includes a divider.
Claim 11
Dependent Claim
60 words
An ignition system for an internal combustion engine as claimed in claim 8, wherein said sooting removing means acts to induce soot cleaning spark discharge in said spark plug or to apply a high voltage not so high as to induce spark discharge in said spark plug during the exhaust stroke or suction stroke of the piston in the engine.
Claim 12
Dependent Claim
36 words
An ignition system for an internal combustion engine as claimed in claim 8, wherein said sooting removing means includes a multiple ignition circuit continuously applying a high voltage at a high frequency to said spark plug.
Claim 13
Dependent Claim
36 words
An ignition system for an internal combustion engine as claimed in claim 8, wherein said predetermined value to be compared with said secondary resistance value is variable depending on at least one of the engine parameters.
Claim 14
Dependent Claim
112 words
An ignition system in accordance with claim 1 wherein said calculating circuit comprises a secondary resistance calculating circuit receiving the secondary current detected by said secondary current detecting resistor and the primary voltage across the primary winding of said ignition coil as its input signals for calculating, on the basis of these input signals, the value of the secondary resistance of said ignition coil, and a primary current control circuit controlling the primary current supplied to the primary winding of said ignition coil so as to increase the spark energy with the increase in the value of the secondary resistance calculated by said secondary resistance calculated by said secondary resistance calculating circuit.
Claim 15
Dependent Claim
121 words
An ignition system for an internal combustion engine as claimed in claim 13, wherein said primary current control circuit includes a primary current detecting resistor connected to the primary winding of said ignition coil for detecting the primary current supplied to the primary winding of said ignition coil, a primary current stabilizing circuit controlling the peak value of the primary current detected by said primary current detecting resistor to limit the peak value to a predetermined setting, and a current compensating circuit acting to increase the peak value of the primary current of said ignition coil limited by said primary current stabilizing circuit when the value of the secondary resistance calculated by said secondary resistance calculating circuit exceeds the predetermined value.
Claim 16
Dependent Claim
96 words
An ignition system for an internal combustion engine as claimed in claim 13, wherein said primary current control circuit includes a dwell angle control circuit controlling the duration of the primary current supplied to the primary winding of said ignition coil in response to the ignition signal generated from said ignition signal generator, and a current compensating circuit acting to elongate the duration of the primary current of said ignition coil limited by said dwell angle control circuit when the value of the secondary resistance calculated by said secondary resistance calculating circuit exceeds the predetermined value.
Claim 17
Dependent Claim
48 words
An ignition system for an internal combustion engine as claimed in claim 14 or 15, wherein the predetermined value of the second resistance compared in said current compensating circuit with the calculated value of the secondary resistance is variable depending on at least one of the engine parameters.
References Cited (Backward Citations)
US3421069A
Cited
US3841287A
Cited
US3902471A
Cited
US4176645A
Cited
US4114582A
Cited
US4153032A
Cited
US4196711A
Cited
US4267813A
Cited
US4275702A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1986-04-25 | 1986-10-25 | 1987-04-26 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1990-04-25 | 1990-10-25 | 1991-04-26 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1994-04-25 | 1994-10-25 | 1995-04-26 | $7700.00 | Window Closed / Lapsed |