Internal-combustion engines – High tension ignition system – Current or voltage sensing in coil primary
Patent
1994-05-26
1996-02-06
Wolfe, Willis R.
Internal-combustion engines
High tension ignition system
Current or voltage sensing in coil primary
F02P 305, F02P 1508
Patent
active
054889405
DESCRIPTION:
BRIEF SUMMARY
BACKGROUND OF THE INVENTION
An ignition system for producing sequential spark ignition is known in which a sequential spark ignition is triggered at the firing time and, as a result of the repeated successive control of the output stage upon each switching off of the current of the ignition coil an ignition spark is triggered on the secondary side. In this known arrangement, the ignition spark does not burn out before the time that the primary current is switched on again, so that a certain residual energy is present in the ignition coil upon the switching on again of the primary current. The charging of an individual ignition customarily has the same duration as the charging of the remaining individual ignitions of this sequential sparking ignition. This may have the result, particularly when losses of energy occur, for instance, in the ignition wiring or due to shunts at the spark plug, that the charging of an individual ignition is not sufficient to give off an ignition spark.
SUMMARY OF THE INVENTION
In accordance with the present invention the residual energy remaining in the coil is determined upon reconnection to the coil, and the conditions prevailing at the spark plug can be noted therefrom. Thus, it is possible, in the event of too little residual energy, to conclude that there is a shunt at the spark plug. Another advantage of the system according to the present invention is that, by the evaluation of the residual energy, it is possible to draw conclusions as to the formation of the mixture; thus, for instance, too low a residual energy permits the conclusion that there is a fat mixture while a very high residual energy permits the conclusion that there is a lean mixture. Particularly upon starting, it affords the possibility of improving the formation of the mixture. Finally, it may also be mentioned that by the recognition of a shunt, the disconnect current for the following individual ignition of the sequential spark ignition can be increased so that the spark plug may possibly burn itself free and the shunt be eliminated.
In accordance with a further embodiment of the present invention, the control device, after a comparison of the detected primary initial current with a predetermined reference value (this reference value being predetermined as a function of the operating condition and the type of engine) will, in the event of a smaller primary initial current than the reference value, increase the disconnect current for the following individual ignition by a switch member which is actuated by the control device. In this connection, it is particularly advantageous that the increase in the disconnect current is possible by increasing the base current of the output stage if the output stage is designed for this and is still not yet in a completely open condition (current limitation), since otherwise the disconnect current can be increased only by an increase in the closing time of the output stage. In this case, a higher supply voltage can be dispensed with. Furthermore the increase of the disconnect current of the following individual ignition can be increased by the lengthening of the closing time for this individual ignition if the output stage has not yet reached the current of the current limitation, i.e. if the current can rise further by an increase in the closed time. In this connection, neither a change in the supply voltage nor in the control signal is necessary for the output stage. The increase in the primary disconnect current can be effected, as desired, only for the following individual ignition or for several individual ignitions, the evaluation of the primary initial current in the control device being decisive.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 shows the basic diagram of an ignition system of an internal combustion engine (not shown);
FIG. 2 shows the execution of a program for the detection and evaluation of the value of the primary initial current; and
FIG. 3 shows a sequential spark ignition.
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 shows the basic dev
REFERENCES:
patent: 3624487 (1971-11-01), Segall
patent: 3945362 (1976-03-01), Neuman et al.
patent: 4773380 (1988-09-01), Narita et al.
patent: 4899715 (1990-02-01), Koiwa et al.
patent: 4915086 (1990-04-01), Ciliberto et al.
patent: 5056497 (1991-10-01), Akagi et al.
patent: 5127388 (1992-07-01), Cicalese et al.
patent: 5208540 (1993-05-01), Hoeflich
patent: 5370099 (1994-12-01), Koelle et al.
Gollin Walter
Kugler Karl-Heinz
Riedel Karlheinz
Zimmermann Christian
Robert & Bosch GmbH
Wolfe Willis R.
LandOfFree
Ignition system for internal combustion engines does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Ignition system for internal combustion engines, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Ignition system for internal combustion engines will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2170928