Equipment for recognizing misfiring
First Claim
1. An equipment for recognizing misfirings in an externally controlled ignition internal combustion engine comprisingplural ignition circuit means each including a spark plug,an ignition distributor means for conducting an ignition voltage in predetermined order to said plural ignition circuit means,at least one differentiating circuit means constructed as a high-pass filter means coupled to each ignition circuit means between the ignition distributor means and the respective spark plug for decoupling a voltage signal from the ignition circuit means, a voltage circuit being exclusively associated with the voltage changes occurring at the initiation of the ignition spark over the spark gap of the plug,a reference voltage circuit means for generating electrical output signals characteristic of the firing point in the ignition circuit means,OR gate means receiving the output of the high-pass filter means, andanalysis and indicator circuit means receiving the output of the OR gate means for producing output signals characteristic of correct or erroneous functioning of the ignition system by logic processing of the filter means output signals and of the output signals of the reference circuit means.
1 Assignment
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Accused Products
Abstract
An equipment for recognizing misfiring, which is particularly suitable for permanent installation in a motor vehicle. By means of high-pass filters coupled to the plug leads between the spark distributor and the spark plugs, the change to the voltage at the spark plugs associated with the initiation of the ignition spark is sensed. The high-pass filters are so arranged that they only send on a needle-shaped output pulse signal to an analysis circuit if it appears with the change in voltage associated with the spark front. The analysis circuit generates appropriate output signals with reference pulses generated in time with the ignition pulses. The high-pass filters are preferably arranged as simple RC filters whose capacities are coupled to the plug leads by means of peripheral electrodes, which at least partially surround the insulation coatings of the plug leads.
37 Citations
37 Claims
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1. An equipment for recognizing misfirings in an externally controlled ignition internal combustion engine comprising
plural ignition circuit means each including a spark plug, an ignition distributor means for conducting an ignition voltage in predetermined order to said plural ignition circuit means, at least one differentiating circuit means constructed as a high-pass filter means coupled to each ignition circuit means between the ignition distributor means and the respective spark plug for decoupling a voltage signal from the ignition circuit means, a voltage circuit being exclusively associated with the voltage changes occurring at the initiation of the ignition spark over the spark gap of the plug, a reference voltage circuit means for generating electrical output signals characteristic of the firing point in the ignition circuit means, OR gate means receiving the output of the high-pass filter means, and analysis and indicator circuit means receiving the output of the OR gate means for producing output signals characteristic of correct or erroneous functioning of the ignition system by logic processing of the filter means output signals and of the output signals of the reference circuit means.
Specification