JPS6038553B2 - 2-line ignition timing control device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to measures against failure in a device that electronically determines the ignition timing of a device having a two-line ignition system.

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. Micro Conview Outer Store
It is a do-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 shows a device for independently controlling 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, and 7 and 8 are transistors 301 and 401 that drive the ignition coils 9 and 10 are output terminals. 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. 2a, and sends it to each processing device 3, 4. do.

Although not shown, each processing device 3 and 4 receives signals such as cooling water temperature, intake temperature, and manifold negative pressure via an A/D converter, and receives these information and rotation signals from the detector 2. From the numerical information, as shown in Figure 2 b and c, the appropriate advance angle a
,,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 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, the ignition coils 9,1
A drive signal of 0 is generated and output to the output terminals 301 and 401, and a coil current as shown in FIG.
As shown in Figure 1, in devices using microcomputers, the processing operations are performed in chronological order according to a predetermined program, and by their nature, they are susceptible to electrical noise. Once the device has deviated from the normal sequential processing operation due to malfunctions caused by such factors, it may not return to the 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 a signal from the detector 2 when an abnormality occurs. The case where this method is adopted in the device shown in Figure 1 is shown in Figure 3.
As shown in the figure. In FIG. 3, 11 and 12 are abnormality detection circuits, 13 and 14 are switching circuits, and 302 and 402 are output terminals.

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 at every predetermined cycle are outputted to output terminals 302 and 402 according to a program.

The abnormality detection circuits T1 and 12 are formed 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 that the abnormality detection circuits 11 and 12
outputs an "H" level signal to the switching circuits 13 and 14. Therefore, the output terminals of the switching circuits 13 and 14 receive the output signals of the processing devices 3 and 4 corresponding to the ignition coils 9 and 1 as ignition command signals in normal conditions, and the output signals of the detector 2 in abnormal conditions. is output as an ignition command signal and drives the ignition coils 9 and 10, respectively. According to this method, even if normal ignition timing control becomes impossible due to an abnormality in the microcomputer, ignition is possible according to the output signal of the detector 2, so although it may cause malfunction of the internal combustion engine, For example, in the case of a car, it is possible to continue driving. The present invention was made in view of the above-mentioned malfunction of the internal combustion engine, and is configured such that when one processing device is abnormal, both 0 ignition coils are driven by the ignition command signal of the normal processing device. The purpose is to improve the malfunction of the internal combustion engine by making the ignition command signal at the time of the engine have advance angle cleanliness for use in abnormal situations. FIG. 4 is a circuit diagram showing an embodiment of the present invention, and is completely the same as FIG. 3 except that input terminals 303 and 403 are added and the connection of switching circuits 13 and 14 is different. . Further, in FIG. 4, the same symbols as in FIG. 3 indicate the same or equivalent parts. In FIG. 4, each processing device 3,
4 is normal, the outputs of the abnormality detection circuits 11 and 12 are “
Since the ignition coils 9 and 10 are at L" level, each ignition coil 9, 10 is disturbed by the output signal of the corresponding processing device 3, 4. Now, if the processing device 4 is abnormal, the output signal of the abnormality detection circuit 12 becomes "H" level, and the switching circuit 14 outputs the ignition command signal output from the partner processing device 3 corresponding to the ignition coil 9.

Therefore, the ignition coils 9, 10 are driven by the same ignition command signal. On the other hand, if the processing device 3 is abnormal, both ignition coils 9 and 10 are similarly driven by the ignition command signal output from the processing device 4 to perform simultaneous ignition. On the other hand, the optimum ignition timing when the ignition timings of the two series of ignition systems are set to simultaneous ignition is different from the optimum ignition timing when the ignition timings of each ignition system are set independently. Here, one of the processing devices 3 and 4 is connected to the input terminal 3.
When an abnormality in the partner processing device is detected through 03, 403, this processing device is configured to provide the optimal ignition timing at the time of simultaneous ignition described above. The optimal ignition timing may be stored in advance in the storage devices in the processing units 3 and 4, and may be stored in a table format, stored in a formula, or given to the result obtained by the table format using a certain formula. Many methods can be considered, such as a correction method that multiplies a coefficient. In the above manner, even if one of the two processing devices 3, 4 is in an abnormal state such as a failure, the two ignition coils 9, 10 can be driven in the simultaneous ignition method. Since this ignition timing is the optimum ignition timing as the simultaneous ignition ignition timing, it is possible to significantly improve the malfunction of the internal combustion engine during the above-mentioned abnormality, compared to the method shown in FIG.

In the method shown in FIG. 4, the probability that both processing devices become abnormal at the same time is extremely low, and it goes without saying that the method of the present invention is superior to the method shown in FIG. 3 from a practical standpoint. As described above, according to the present invention, in a device that processes two ignition systems using two processing devices, by using an abnormality detection circuit and a switching circuit that monitor the operation of each processing device, one If the processing device is abnormal, both ignition coils are driven by the ignition command signal of the normal processing device, and the ignition timing is set to be optimal for simultaneous ignition. Even in the event of an abnormality such as a failure, malfunctions of the internal combustion engine can be kept to a minimum, and the reliability of the device can be improved.

[Brief explanation of the drawing]

1 and 3 are circuit diagrams based on the follower method, FIG. 2 is a waveform diagram of FIG. 1, and FIG. 4 is a circuit diagram showing an embodiment based on the present invention. In the figure, 1 is a gear, 2 is a detector, 3, 4 are processing devices, 5, 6 are resistors, 7, 8 are transistors, 9, 1 Kawama ignition coil, 101, 401 are outputs of processing devices 3, 4 Terminals, 11 and 12 are abnormality detection circuits, 13 and 14 are switching circuits,
302, 402 are output terminals of the processing devices 3, 4, 303,
Reference numeral 403 indicates input terminals of the processing devices 3 and 4. Note that the same symbols in each figure indicate the same or equivalent parts. Figure 1 Figure 2 Figure 3 Figure 4

Claims (1)

[Claims] 1. A detector installed to detect a predetermined crank angle as a reference position signal, two ignition coils, two processing devices that execute serial processing in time series using a stored program method, and the two A processing device that independently controls ignition timing for each of the two ignition coils based on the output signal of the detector,
Each of the processing devices has an output terminal for obtaining a signal generated according to a program, two abnormality detection circuits connected correspondingly to each of the output terminals, an output signal of one of the abnormality detection circuits, inputting two ignition command signals output from the two processing devices to each ignition coil, and outputting an ignition command signal output by each of the processing devices corresponding to each of the ignition coils under normal conditions; A switching circuit configured to output an ignition command signal output from a normal processing device when one of the processing devices is abnormal, and an input of the processing device for mutually inputting the output signals of the respective abnormality detection circuits. terminal, and when the output signal of one abnormality detection circuit indicates an abnormality, the processing device corresponding to the other abnormality detection circuit indicating normality gives an advance angle characteristic different from that given to the one ignition coil corresponding to the normality. A two-line ignition timing control device characterized in that it is configured to output advance angle characteristics as an ignition command signal.