JPS6038554B2 - 2-line ignition timing control device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides a two-line ignition timing control device that is capable of improving malfunctions of an internal combustion engine when a failure occurs in a device that electronically determines the ignition timing of a device having a two-line ignition system. Regarding.

Electronic ignition timing control devices are increasingly being adopted as ignition devices for internal combustion engines.

Among these, devices using microcomputers have been particularly in the spotlight in recent years. This tendency also applies to internal combustion engines having two independent ignition systems, such as rotary engines. The microcomputer uses a stored program system, and its control specifications can be easily changed using a program.

Furthermore, it has greatly contributed to the miniaturization and higher precision of devices. FIG. 1 is a circuit diagram showing a conventional two-line ignition timing control device that independently controls the ignition timing of an internal combustion engine having two ignition coils using two microcomputers.

In Fig. 1, 1 is a gear attached to an object that rotates in synchronization with the crankshaft, 2 is a detector that detects the position of the teeth of gear 1, and 3 and 4 are appropriate ones for each ignition coil 9 and 10. A processing device using a microcomputer that controls the ignition timing, 5 and 6 are resistors, 7 and 8 are transistors that drive the ignition coils 9 and 10, and 301 and 401 are output terminals of the processing devices 3 and 4, respectively. show. In FIG. 1, a detector 2 detects the position of the tooth of a gear 1 set at the top dead center of the engine, generates an output signal as shown in FIG. Send to 4.

Although not shown, each processing device 3, 4 receives signals such as cooling water temperature, intake temperature, manifold negative pressure, etc. via an A/D converter, and receives these information and the rotation speed from the detector 2. From the information, as shown in Figure 2 b and c, the appropriate advance angle 8
,,82, and calculate the advance angle 8,,82 by the time T,,T from the reference position given by the output signal of the detector 2.
2 to determine the ignition timing of each ignition coil 9, 10. Further, the processing devices 3 and 4 give each ignition coil 9 and 10 an energizing time for a time determined based on temperature, voltage, and the like.

In this way, drive signals for the ignition coils 9 and 10 are generated and output to the output terminals 301 and 401, so that a coil current flows through each ignition coil 9 and 1 as shown in Fig. 2 b and c. Ignites during a tornado or outage. As shown in Figure 1, in a device using a microcomputer, its processing operations execute serial processing in chronological order according to a predetermined program, and due to its nature, it is susceptible to electrical noise. Once the system is out of normal sequence processing due to malfunction, it may not return to normal operation again.

A method has been proposed in which an abnormality detection circuit is added to detect such an abnormality or a failure of the microcomputer, and the ignition coil is driven by the signal from the detector 2 when the abnormality occurs.

FIG. 3 shows a case where this method is adopted in the apparatus shown in FIG. 1.
In FIG. 3, 11 and 12 are abnormality detection circuits, 13 and 1
Reference numeral 4 indicates a switching circuit, and reference numerals 302 and 402 indicate output terminals of the processing devices 3 and 4.

Note that the same symbols as in FIG. 1 in the figure indicate the same or equivalent parts. In FIG. 3, signals that are inverted every predetermined cycle are outputted to output terminals 302 and 402 according to a program. The abnormality detection circuits 11 and 12 are composed of, for example, retriggerable monostable multipipulators, and send "L" level signals to the switching circuits 13 and 14 when the inverted signal is normally generated. On the other hand, if the operation of the microcomputers in the processing devices 3 and 4 is abnormal, the above-mentioned inverted signal is not output, so it is output to the abnormality detection circuits 13 and 14. Therefore, the switching circuit 13
, 14 are connected to the respective ignition coils 9, 10 during normal operation.
The output signals of the corresponding processing devices 3 and 4 are output as ignition command signals. In addition, in the event of an abnormality, the output signal of the detector 2 is output as an ignition command signal to the ignition coils 9 and 1, respectively.
0 is driven according to the ignition command signal. According to this method, even if normal ignition timing control becomes impossible due to an abnormality in the microcomputer, the detector 2
Since the ignition coil can be driven by the output signal, for example, in the case of a car, it is possible to continue driving, although the internal combustion engine may malfunction.

This invention was conceived in consideration of the above-mentioned malfunction of the internal combustion engine, and when one processing device is abnormal, both ignition coils are driven by an ignition command signal output from a normal processing device,
Another object of the present invention is to provide a two-series ignition timing control device that can improve the malfunction of the internal combustion engine by driving both ignition coils using the output signal of the detector when both processing devices are abnormal. do. Embodiments of the two-line ignition timing control device of the present invention will be described below with reference to the drawings.

FIG. 4 is a circuit diagram showing one embodiment. In FIG. 4, the same parts as in FIGS. 1 and 3 are designated by the same reference numerals and will only be described in the coffin. As is clear from comparing FIG. 4 with FIG. 3, the switching circuit 13 in FIG.
New switching circuits 15 and 16 are connected to the section 14, and the outputs of the abnormality detection circuits 11 and 12 are respectively supplied to the first and second input terminals of a two-input AND circuit 17. The output is supplied to switching circuits 15 and 16.

The other parts, ie, the gear 1, the detector 2, the processing devices 3 and 4, the resistors 5 and 6, the transistors 7 and 8, and the ignition coil 9 and 1, are the same as those in FIGS. 1 and 3.

The switching circuit 15 includes an AND circuit 15a and a suppression gate 15.
b, 15c, and an OR circuit 15d, which includes the output of the detector 2, the ignition command signal from the output terminal 301 of the processing device 3, the output of the abnormality detection circuit 11, the output of the AND circuit 17, and the output terminal of the processing device 4. The ignition command signal from 401 is input, and these signals are switched and output.

Similarly, the switching circuit 16 is also composed of an AND circuit 16a, suppression gates 16b, 16c, and an OR circuit 16d, and includes the output of the detector 2, the ignition command signal from the output terminal 301 of the processing device 3, and the output of the AND circuit 17. , the output of the abnormality detection circuit 12, and the ignition command signal from the output terminal 401 of the processing device 4 are input, and these signals are switched and output.

Next, the operation of the two-line ignition timing control device of the present invention configured as described above will be explained.

When each processing device 3, 4 is normal, abnormality detection circuit 11, 1
The output signal of AND circuit 1 is at "L" level, and the output signal of AND circuit 1
Since the output signal of 7 also becomes "L" level, each switching circuit 1
An ignition command signal output from a processing device corresponding to each ignition coil 9, 10' appears at the output terminals 5, 16, and each ignition coil 9, 10 is driven by this signal. Now, if the processing device 4 is abnormal, the abnormality detection circuit 12
The output signal becomes "H" level.

Furthermore, since the processing device 3 is normal, the output signal of the abnormality detection circuit 11 is at the "L" level, so the output signal of the AND circuit 17 is at the "L" level. Therefore, the switching circuit 16
An ignition command signal output from the processing device 3 appears at the output terminal of the ignition coil 10, and the ignition coil 10 is driven by this signal.

On the other hand, if the processing device 3 is abnormal, the ignition command signal output from the processing device 4 similarly appears at the output terminal of the switching circuit 15, and the ignition coil 9 is driven by this signal.

Next, when both the processing devices 3 and 4 fail at the same time, the output signals of the respective abnormality detection circuits 11 and 12 both become "H" level, and the output signal of the AND circuit 17 becomes "H" level.

Therefore, the output signal of the detector 2 appears at the output terminal of each switching circuit 15, 16, and each ignition coil 9, 10 is driven in accordance with this signal. As described above, according to the two-line ignition timing control device of the present invention, when one of the two processing devices is abnormal, the two ignition coils are driven by the ignition command signal output from the normal processing device. So,
It is possible to significantly reduce malfunctions of the internal combustion engine during abnormalities and improve the reliability of the device.

Further, if both processing devices become abnormal at the same time, each ignition coil is driven by the output signal of the detector, so the reliability of the device can be further improved.

[Brief explanation of the drawing]

Figure 1 is a circuit diagram of a conventional two-line ignition timing control device;
Figures a to 2c are time charts for explaining the operation of the two-series ignition timing control device shown in Figure 1, and Figure 3
This figure is a circuit diagram showing another example of a conventional two-line ignition timing control device, and FIG. 4 is a circuit diagram of an embodiment of the two-line ignition timing control device of the present invention. 1... Gear, 2... Detector, 3, 4... Processing device, 5, 6...
・Resistor, 7, 8... Transistor, 9, 10... Ignition coil, 11, 12... Abnormality detection circuit, 15, 16...
・Switching circuit, 17...AND circuit, and the same reference numerals in the drawings indicate the same or corresponding parts. Figure 1 Figure 2 Figure 3 Figure 4

Claims (1)

[Claims] 1. A detector that detects a predetermined crank angle as a reference position signal, two ignition coils, calculates an appropriate advance angle from the reference signal from the detector and information on the state of the internal combustion engine, and uses this advance angle as the reference above. two processing devices that output an ignition command signal and its inverted signal for converting the signal into time and executing time-series processing according to a program to determine the ignition timing of the ignition coil; Two abnormality detection circuits detect whether or not there is an abnormality in each processing device from the outputted inverted signal and output an output when there is an abnormality, and when both abnormality detection circuits are outputting by ANDing these two abnormality detection circuits. an AND circuit that outputs, when the abnormality detection circuit detects that one of the two processing devices is abnormal, simultaneously drives the two ignition coils with an ignition command signal output from the normal processing device; When both of the above-mentioned abnormality detection circuits respectively detect an abnormality in both of the above-mentioned processing devices, the output of the above-mentioned detector simultaneously drives both ignition coils, and when both of the above-mentioned processing devices are normal, the output from both processing devices is A two-line ignition timing control device comprising two switching circuits that switch signals so that both ignition coils are driven by the ignition command signal.