JPH10141196A - Ignition device having cylinder discriminating means - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide one position sensor so as to simplify sensor fitting and save the sensor fitting space, and eliminate complicatedness in designing an internal combustion engine by providing a peak hold circuit for holding the peak value of primary counter electromotive force of an ignition coil until the next ignition. SOLUTION: An igniter 2 for interrupting primary current and a peak hold circuit 4, or the base of the igniter 2 and the peak hold circuit 4 are connected to the primary side of the ignition coil 1, and further an ignition plug 3 is connected to the secondary side output of the ignition coil 1. When a pulse signal is supplied to the base (a) part of the igniter 2, high pressure is generated on the secondary side of the ignition coil 1 when pulse waveform starts to cause discharge in the ignition plug 3. At this time, counter electromotive force is obtained at the primary side (b) part of the ignition coil 1. The electromotive force is peak-hold processed by the peak hold circuit 4 to hld the peak value of the primary counter electromotive force of the ignition coil 1 until the next ignition.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ignition device used for an internal combustion engine for a vehicle, and more particularly to an ignition device provided with a cylinder discriminating means used for judging ignition timing of a multi-cylinder internal combustion engine.

[0002]

2. Description of the Related Art In a conventional internal combustion engine ignition device, an igniter including a power transistor or the like for interrupting (conducting control) a primary current is connected to a primary side of an ignition coil composed of a step-up transformer. An ignition plug is connected to the secondary output, and an ignition operation is performed by giving an ignition signal to the igniter.

In the above-described ignition device, an ignition signal is given to an igniter for each cylinder at an ignition position of each cylinder, and the ignition signal is obtained from a cylinder discrimination signal described later. As is well known, such a cylinder discrimination signal outputs a position detection signal by detecting a magnetic drum having a predetermined pattern of magnetic poles attached to an output shaft of an engine and the magnetic or magnetic resistance of the magnetic drum. Using a position detection sensor composed of a plurality of Hall elements and the like, a signal indicating the crank angle of the internal combustion engine at each predetermined angle and a signal corresponding to the compression top dead center of the predetermined cylinder are generated. There is known an apparatus that obtains a signal for cylinder determination based on the signal.

[0004]

As described above, the conventional internal combustion engine ignition device for obtaining a cylinder discrimination signal by using a plurality of position detection sensors requires a mechanism for mounting a magnetic drum and a position detection sensor. Not only becomes complicated and costly, but also the design of the internal combustion engine becomes complicated, and there is a problem that it is difficult to reduce the size of the internal combustion engine body in order to secure a space for mounting each sensor. .

SUMMARY OF THE INVENTION In view of the above-mentioned problems, an object of the present invention is to provide an internal combustion engine ignition device that can distinguish a cylinder by using only one position detection sensor as in the prior art.

[0006]

SUMMARY OF THE INVENTION In an ignition device in which an igniter is connected to a primary side of an ignition coil and an ignition plug is connected to a secondary side thereof, a peak value of a primary back electromotive force of the ignition coil is held until the next ignition. An ignition device comprising a cylinder discriminating means, comprising:

[0007]

FIG. 1 shows a circuit configuration of an ignition device provided with an ion current detection device according to the present invention. In FIG. 1, an igniter 2 composed of a power transistor for interrupting the primary current (conduction control) and a peak hold circuit 4 described later are connected to the primary side of an ignition coil 1 composed of a step-up transformer.
A base of the igniter 2 and a peak hold circuit 4 are connected, and a secondary output of the ignition coil 1 is connected to an ignition plug 3. As shown in FIG. 1, the peak hold circuit 4 connects a first operational amplifier to a connection of a voltage dividing resistor, and outputs the output to a second operational amplifier via a diode and a capacitor and a transistor connected in parallel. It is formed by being connected.

The operation of the circuit configured as described above will be described with reference to FIG. FIG. 2 shows signal waveforms at respective points in FIG. As is well known, when the pulse signal shown in FIG. 2A is supplied to the base a of the igniter 2, when this pulse waveform falls, a high voltage is generated on the secondary side of the ignition coil 1, and discharge occurs in the ignition plug 3. Occurs. At this time, a back electromotive force is obtained at the primary side b of the ignition coil 1 as shown in FIG. The peak holding circuit 4 performs peak holding processing on the back electromotive force, so that a waveform (c) is output from the output terminal c. The waveform (f) has an arbitrary threshold value.

The pulse signal (a) is supplied to a predetermined cylinder. In this supply method, for example, the top dead center of a certain process is set to 0.
The pulse signal (a) is supplied at 180 ° CA intervals, that is, at each dead center of the intake, compression, expansion, and exhaust strokes. At this time, one position sensor indicating each dead point is required.

During the compression stroke, the pressure in the cylinder is high and the breakdown voltage of the spark plug is high, so the back electromotive force generated on the primary side of the ignition coil 1 is extremely large as shown in the waveform (d) of FIG. Become. But other processes, intake, expansion,
In the exhaust stroke, the pressure in the cylinder is normal pressure, or
Since the pressure becomes negative, the back electromotive force generated on the primary side of the ignition coil 1 becomes small as shown in the waveform (e). This is peak-held by the peak-hold circuit 4 using the pulse signal (a) as a reset signal, and the output is compared to detect the compression top dead center of a predetermined cylinder.

The above-mentioned comparison method is performed by a comparator including an operational amplifier or the like which outputs H when the waveform exceeds the threshold waveform (f) in FIG. 2 and outputs L when the waveform falls below the waveform (f). , H can be determined to be the compression top dead center of the predetermined cylinder.

Therefore, in the present invention, cylinder discrimination can be performed by the one position detection sensor and the means for detecting the compression top dead center of the predetermined cylinder. For example, in the case of a 4-cylinder internal combustion engine that burns in the order of 1st to 3rd, 4th and 2nd cylinders, if the predetermined cylinder is the 1st cylinder, as is well known, the top dead center of the 1st cylinder Is set to 0 ° C. and the next bottom dead center is set to 180 ° A. At this time, in the case of a normal four-cylinder internal combustion engine, the top dead center of the first cylinder is also the top dead center of the fourth cylinder. Therefore, at the time of starting the internal combustion engine, it is not clear which of the first and fourth cylinders is 0 ° C. 4 which is the compression top dead center. As described with reference to FIGS. 1 and 2, the compression top dead center is detected by supplying the pulse signal (a) to the first cylinder. If the compression top dead center is 180 ° C., the compression top dead center of the third cylinder to be burned next is 180 ° C.
A (when the position sensor is 360 ° C.).
At this time, if the ignition pulse is supplied at predetermined timing from the third cylinder to the fourth, second, and first cylinders, the internal combustion engine starts,
Thus, cylinder determination is performed.

The comparison of the output signal waveforms described above may be performed not only by a comparator comprising an operational amplifier or the like but also by an internal combustion engine controller.

[0014]

As described above, according to the present invention, one position detection sensor, which conventionally required a plurality of cylinders, can be provided. Therefore, the sensor mounting space can be simplified and space can be saved, and the complexity of designing the internal combustion engine can be eliminated.

[Brief description of the drawings]

FIG. 1 is a circuit diagram of an internal combustion engine ignition device showing an embodiment of the present invention.

FIG. 2 is a signal waveform for describing the operation of FIG. 1;

[Explanation of symbols]

 In the drawings, the same reference numerals indicate the same or corresponding parts. Reference Signs List 1 ignition coil 2 igniter 3 spark plug 4 peak hold circuit

Claims (2)

[Claims] 1. An ignition device in which an igniter is connected to a primary side of an ignition coil and an ignition plug is connected to a secondary side thereof, a peak hold circuit for holding a peak value of a primary back electromotive force of the ignition coil until next ignition. An ignition device comprising a cylinder discriminating means, comprising: 2. An igniter on a primary side of an ignition coil;
In an ignition device having a spark plug connected to the next side, a peak hold circuit for holding a peak value of a primary back electromotive force of the ignition coil until the next ignition, and a compression top dead center of the internal combustion engine by an output from the peak hold circuit. An ignition device comprising a cylinder discriminating means for detecting a point and performing cylinder discrimination.