JPS6038552B2 - 2-line ignition timing control device - Google Patents

Description

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

Electronic ignition timing control devices are widely used as ignition systems for internal combustion engines.

Among these, devices using microcomputers have been particularly in the spotlight in recent years. This concept also applies to internal combustion engines having two independent ignition systems, such as rotary engines. The microcomputer is a stored program system.

The control specifications can be easily changed using the 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 for each ignition coil 9, 101. 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 indicate output terminals of the processing devices 3 and 4, respectively. . In FIG. 1, a detector 2 detects the position of the teeth of a gear 1 installed at the top dead center of the engine, generates an output signal as shown in FIG. Send to. Each processing device 3, 4
Although not shown, signals such as cooling water temperature, intake temperature, and manifold member pressure are input via an A/D converter.
Based on this information and the rotation speed information from the detector 2, an appropriate advance angle a. , 82, and convert this advance angle 0, , 82 into the time T, , T2 from the reference position given by the output signal of the detector 2,
The ignition timing of each ignition coil 9, 10 is determined. Further, the processing devices 3 and 4 give the energization time of each ignition coil 9 and 10 for a time determined by the constant temperature, voltage, etc. of the ignition coil.

In this way, drive signals for the ignition coils 9, 10 are generated and output to the output terminals 301, 401, causing coil currents to flow through each ignition coil 9, 10' as shown in FIGS. 2b and 2c. Lights during haze or outage. In a device using a microcomputer as shown in Figure 1, its processing operations are performed according to a predetermined program.
It executes serial processing in chronological order, and due to its nature, once it breaks out of the normal phantom sequential processing operation due to malfunctions caused by electrical noise, it may not return to normal operation again. be.

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 a signal from the detector 2 when an abnormality occurs.

FIG. 3 shows a case where this method is applied to the apparatus shown in FIG. 1. In FIG. 3, 11, 12 are abnormality detection circuits, 13,
14 is a switching circuit, and 302 and 402 are 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, the output terminals 3 of the processing devices 3 and 4
02, 402 is outputted with a signal that is inverted at every predetermined cycle according to the program. Abnormality detection circuit 11
, 12 are constituted by, for example, retriggerable monostable multipipulators, and when the inverted signal is normally generated, the switching circuits 13 and 14 send out signals at the rL level. On the other hand, if the microcomputers in the processing units 3 and 4 are operating abnormally, the above-mentioned inverted signal is not output, so the abnormality detection circuits 11 and 12 output "H-level signals to the switching circuits 13 and 14". do.

Therefore, the output signals of the processing units 3 and 4 corresponding to the respective ignition coils 9 and 10 are output as ignition command signals to the output terminals of the switching circuits 13 and 14 during normal operation.

Further, when an abnormality occurs, the output signal of the detector 2 is outputted as an ignition signal to drive the respective ignition coils 9 and 10. According to this method, even if normal ignition timing control becomes impossible due to an abnormality in the microcomputer, the detector 2
Since ignition is not possible according to the output signal of , the internal combustion engine malfunctions, but it is possible to drive the car without stopping.

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 the ignition command signal of the normal processing device. 2 that can improve the malfunction of the institution
The purpose of the present invention is to provide a series ignition timing control device.

Hereinafter, embodiments of the two-line ignition timing control device of the present invention will be described based on the drawing.

FIG. 4 is a circuit diagram showing the configuration of one embodiment. In this Fig. 4, the same parts as those in Fig. 1 and Fig. 3 will be described with the same reference numerals.As is clear from comparing Fig. 4 with Fig. 3, Switching circuit 1 in
3 and 14 are different, and the other parts are the same as in FIG.

That is, gear 1, detector 2, processing devices 3, 4, resistor 5
, 6, transistor 7, 8, ignition coil 9, 1 river first
It is similar to FIG. 3. The switching circuit 13 is composed of a deterrent gate 13a, an AND circuit 13b, and an OR circuit 13c, and a first input terminal of the deterrent gate 13a is connected to an output terminal 301 of the processing device 3. Deterrence gate 13
The output terminal of the abnormality detection circuit 11 is connected to the second input terminal of a. The output terminal of the suppression cable 13a is an OR circuit 13c.
is connected to the first input terminal of. A first input terminal of the AND circuit 13b is connected to an output terminal of the abnormality detection circuit 11. The second input terminal of the AND circuit 13b is wired to the output terminal 401 of the processing device 4. The output terminal of the AND circuit 13b is connected to the second input terminal of the OR circuit 13c. The output terminal of the OR circuit 13c is connected to the base of the transistor 7 via the resistor 5. Further, the reversal circuit 14 includes an AND circuit 14a, a suppression gate 14b, and an OR circuit 14c, and the first input terminal of the AND circuit 14a is connected to the processing device 3.
The first input terminal is connected to the output terminal of the abnormality detection circuit 12.

The output terminal of the AND circuit 14a is connected to the first input terminal of the OR circuit 14c. Further, the first input terminal of the inhibition gate 14b is connected to the output terminal of the abnormality detection circuit 12, and the second input terminal of the inhibition gate 14b is connected to the output terminal 401 of the processing device 4.

The output terminal of the inhibition gate 14b is connected to the second input terminal of the OR circuit 14c. The output terminal of the OR circuit 14c is the resistor 6
It is connected to the base of transistor 8 via. Next, the operation of the two-line ignition timing control device of the present invention configured as described above will be explained.

If each processing device 3, 4 is normal, the abnormality detection circuit 11,
12 is at the "L" level, and the ignition coils 9, 10
is driven by the output signal of the corresponding processing device. If the processing device 4 is abnormal, the output signal of the abnormality detection circuit 12 is “
The level becomes "H", indicating an abnormality. At this time, the ignition coil 9
Since the ignition command signal output from the corresponding processing device 3 on the other side is output to the output terminal of the switching circuit 14, the ignition coils 9 and 10 are driven by the same ignition command signal. Conversely, if the processing device 3 is abnormal, both ignition coils 9,
1 is driven by an ignition command signal output from the processing device 4.

By doing the above, if the operation of one processing device is no longer normal, both ignition coils 9 and 10 can be driven by the ignition command signal output by the normal processing device, as shown in Fig. 3. Compared to conventional methods, malfunctions of the internal combustion engine during abnormal conditions can be significantly improved.

In FIG. 4, the probability that both processing devices 3 and 4 become abnormal at the same time is extremely low, and from a practical standpoint, it goes without saying that this invention is superior to the method shown in FIG. 3. .

As described above, according to the two-series ignition timing control device of the present invention, in a device that processes an ignition system having two ignition coils using two processing devices, an abnormality detection circuit that monitors the operation of each processing device is provided. By using a switching circuit, when one processing device is abnormal, it is possible to drive both ignition coils with the ignition command signal output by the normal processing device, so even if the processing device is abnormal, It is possible to ignite the internal combustion engine with minimal malfunction, and it is also possible to improve the reliability of the device.

[Brief explanation of drawings]

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 embodiment of the conventional two-series ignition timing control device, and FIG. 4 is a circuit diagram of one embodiment of the two-series ignition timing control device of the present invention. DESCRIPTION OF SYMBOLS 1... Gear, 2... Detector, 3, 4... Processing device, 5, 6... Resistor, 7, 8... Transistor, 9, 10... Ignition coil, 11, 12... Abnormality detection circuit, 13, 14 ...Switching circuit. Note that the same reference numerals in the figures indicate the same or corresponding parts. 1st
Figure 2 Figure 3 Figure 4

Claims (1)

[Claims] 1 A detector that detects a predetermined crank angle as a reference 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 calculates the advance angle from the reference signal. 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 that detect whether or not there is an abnormality in each processing device from the inverted signal that is detected and output an output when there is an abnormality; when the abnormality detection circuit detects that one of the two processing devices is abnormal; The above two ignition coils are simultaneously driven by the ignition command signal output from the normal processing device, and when both of the above abnormality detection circuits respectively detect an abnormality in both the above processing devices, the output of the above detector is used to drive both ignition coils. Two switching circuits are provided that simultaneously drive the ignition coils and, when both of the processing devices are normal, switch signals so as to drive both of the ignition coils in response to the ignition command signal output from both of the processing devices. A two-line ignition timing control device.