Method of associating ignition signals with a reference cylinder

Details Method of associating ignition signals with a reference cylinder Method of associating ignition signals with a reference cylinder

1991-07-24

1992-04-28

Wolfe, Willis R.

Internal-combustion engines

High tension ignition system

Electronic cylinder sequencing

123636, 123644, F02P 5145, F02P 1508

Patent

active

051078171

DESCRIPTION:

BRIEF SUMMARY
BACKGROUND OF THE INVENTION

The invention is based on a method for associating ignition signals with a reference cylinder in multiple-spark ignition systems of internal combustion engines having externally supplied ignition.
To make the performance of precise testing of the ignition system of internal combustion engines possible, synchronization of the ignition system test unit with a reference signal is required. In ignition systems having a distributor, the ignition at the reference cylinder is detected with the aid of a trigger signal pickup, which is connected by means of the ignition cable leading to the reference signal, and is passed on to the ignition system test unit for evaluation and synchronization.
This method is unsuitable for multiple-spark ignition systems, because there is no mechanical distributor. In such ignition systems, a number of double-spark ignition coils corresponding to half the number of cylinders is used; these coils have two separate high-voltage windings, or preferably one such winding, which then generates two high-voltage signals of unlike polarity. It is also possible, however, to assign one ignition coil to each spark plug, with two or more ignition coils generating ignition pulses simultaneously. Ignition takes place in only one cylinder in the working stroke, while in the other cylinders, the ignition sparks remain without effect. The actual ignition spark is called the primary spark, while the other ignition spark is called the supporting spark.
In such ignition systems, the association of the ignition signals with a reference cylinder with the aid of a trigger signal pickup connected to the ignition cable leading to the reference signal is ambiguous, because the pickup outputs a signal both for the primary spark and for the supporting spark. Unequivocal synchronization of the ignition system test unit with the ignition signals for the reference signal would thus not be possible.
German Patent 33 25 308 discloses an ignition signal adaptor for distributorless ignition systems of internal combustion engines with externally supplied ignition, in which the signals detected by trigger tongs clamped to the two ignition lines connected to a double-spark ignition coil are delivered to a synchronizing stage, at the output of which the pulse train of actual ignition pulses is output for either one or the other cylinder. Synchronization with the actual ignition pulses in the reference signal is effected by depressing a key, which causes the output signal to switch over from one pulse train to the other.


ADVANTAGES OF THE INVENTION

The method according to the invention has the advantage that the association of ignition signals with a reference signal takes place automatically. Within a certain engine operating range, the primary and supporting sparks generated in double-spark ignition coils are distinguished by the magnitude of the ignition voltages. Since the compression and both the mixture present and the mixture dynamics vary in the working stroke and in the exhaust stroke, the primary spark generally requires a substantially higher ignition voltage than the supporting spark.
In a first exemplary embodiment of the method according to the invention, it is provided that the association of ignition signals with a reference signal is ascertained from a comparison of the level of the high-voltage signals occurring at the reference signal with a reference level derived from the high-voltage signals. In an advantageous feature of the first exemplary embodiment, it is provided that the reference level is ascertained from the signals having a lower level in comparison with the levels of the preceding signals.
Both the ignition voltage occurring at the reference signal, which is for instance picked up by a capacitive transducer, and the spark current detectable by an inductive transducer, which is measurable after ignition, are suitable for evaluating the signal level.
In a second, particularly advantageous exemplary embodiment, it is provided that the association of ignition sign

REFERENCES:
patent: 4478201 (1984-10-01), Asik
patent: 4483293 (1984-11-01), Akasu
patent: 4711227 (1987-12-01), Li et al.
patent: 4913123 (1990-04-01), De Biasi et al.
patent: 4915086 (1990-04-01), Ciliberto et al.
patent: 5058560 (1991-10-01), Asakura et al.
patent: 5065729 (1991-11-01), Krauter et al.

Affiliated with

Also associated with

Rating

Method of associating ignition signals with a reference cylinder does not yet have a rating. At this time, there are no reviews or comments for this patent.

If you have personal experience with Method of associating ignition signals with a reference cylinder, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Method of associating ignition signals with a reference cylinder will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFUS-PAI-O-1240469