JPH0942132A - Ignition system failure diagnosis method and ignition system - Google Patents

Abstract

(57) [Abstract] [Purpose] To provide an ignition system that has a failure diagnosis function and that simplifies connection wiring between the ignition systems. [Structure] An engine control unit 1, an ignition device 2, a signal output line 70 connecting the engine control unit and the ignition device, and an ignition coil 4 are included and transmitted from the engine control unit 1 via the signal output line 70. In the ignition system that operates the high voltage generation circuit including the ignition device 2 and the ignition coil 3 to generate a high voltage in the ignition coil 4 based on the ignition signal, a high voltage is generated to the engine control unit 1 via the signal output line 70. A feedback circuit 18 for feeding back operation information indicating a normal / abnormal state of the circuit and a diagnostic circuit 17 for diagnosing the operation of the high voltage generation circuit based on the operation information are provided.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ignition system failure diagnosis method and an ignition system.

[0002]

2. Description of the Related Art As a conventional technique for diagnosing a failure in an ignition system, there is one disclosed in Japanese Patent Laid-Open No. 63-295839, which states that "the OR signal of a misfire state detection signal for each cylinder is input. It can be understood from the description of "Misfire detection means for detecting the misfire state of each cylinder" and the drawings, the signal detected from the primary side of the ignition coil is returned to the engine control unit for feedback only. Further, nothing is described about a concrete signal processing method and a feedback circuit.

Further, Japanese Patent Application Laid-Open No. 1-2224475 describes the extraction of signals relating to the configuration of the OR circuit in the above publication, but the output signal from the engine control unit to the ignition device and the failure or A separate wiring is used for the misfire detection signal.

[0004]

In the above prior art,
Dedicated wiring is provided for fault diagnosis of the ignition system, and the wiring between the ignition systems is complicated. In other words, there is room for improvement in compatibility with existing ignition systems. Therefore, an object of the present invention is to provide an ignition system failure diagnosis method and an ignition system in which connection wiring between the ignition systems is simplified.

[0005]

The above object is to operate a high voltage generating circuit composed of an ignition device and an ignition coil on the basis of an ignition signal transmitted from an engine control unit through a signal output line to generate a high voltage. The operation information indicating the normal / abnormal state of the high voltage generating circuit is fed back to the engine control unit through the signal output line, and the operation of the high voltage generating circuit is diagnosed based on the operation information. It is achieved by a method of diagnosing a failure of an ignition system.

Further, a step of intermittently transmitting an ignition signal from the engine control unit to the ignition device via a signal output line and operating a high voltage generating circuit composed of the ignition device and an ignition coil based on the ignition signal. A step of transmitting a diagnostic signal to the signal output line when the ignition signal is not transmitted, a step of detecting operation information indicating a normal / abnormal state of the high voltage generation circuit, and a step of detecting the operation information detected. Based on the step of canceling or canceling the diagnostic signal transmitted to the signal output line based on the basis, the step of detecting an electrical change caused by the presence or absence of the cancellation of the diagnostic signal, and from the electrical change A method of diagnosing a failure of an ignition system, the method including the step of performing a failure diagnosis of the high voltage generation circuit.

Further, an ignition system for achieving the above object includes an engine control unit, an ignition device, a signal output line connecting the engine control unit and the ignition device, and an ignition coil, and the engine via the signal output line. In an ignition system that operates a high voltage generation circuit composed of the ignition device and the ignition coil based on an ignition signal transmitted from a control unit to generate a high voltage in the ignition coil, the engine via the signal output line. The control unit is provided with means for feeding back operation information indicating normal / abnormal states of the high voltage generating circuit, and means for diagnosing the operation of the high voltage generating circuit based on the operation information.

[0008]

According to the above construction, since the operation information indicating the normal / abnormal state of the high voltage generating circuit is propagated to the engine control unit side through the same signal output line, even if there is no dedicated wiring for failure diagnosis. The operation of the high voltage generating circuit, that is, the operation of the ignition device and the ignition coil can be diagnosed by the engine control unit based on the operation information.

In other words, the diagnostic signal is transmitted at the time when the ignition signal is not transmitted from the engine control unit (the timing of non-ignition), and the diagnostic signal is offset so as not to accidentally become the ignition signal. Then, the failure diagnosis of the ignition device or the ignition coil can be performed from the deviation of the electric change of the output line in the engine control unit generated by the diagnostic signal. At this time, since the diagnostic signal does not overlap with the ignition signal, the signal output line can be shared and the dedicated wiring for failure diagnosis can be eliminated.

[0010]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a diagram showing a configuration of an ignition system according to an embodiment of the present invention. The ignition system includes an engine control unit 1 (hereinafter, ECU 1
Abbreviated), an ignition device 2, an ignition coil 3, a diagnostic circuit 17, a feedback circuit 18, and a signal output line 70. The spark plug 4 may be included.

The output line of the ECU 1 includes a PNP transistor 9, an NPN transistor 10 (hereinafter transistor is abbreviated as Tr), and resistors 11 and 12 (hereinafter abbreviated as R). The ECU 1 turns ON / OFF the Trs 9 and 10 at proper ignition timing, and sends an ignition signal (pulse signal) to the ignition device 2 via the signal output line 70.
Is sent intermittently. The ignition device 2 includes a power transistor 5 (hereinafter abbreviated as a power transmission 5), a low current detection resistor 6 for detecting a primary current of the ignition coil 3, a current control circuit 7, and a resistor 8. To be done.

The ignition system having the above-mentioned structure is provided in the ECU.
Based on the ignition signal from 1, the power transmission 5 is energized by LOW → HIGH and cut off by HIGH → LOW, and the ignition device 2
By operating a high voltage generating circuit on the primary side composed of the ignition coil 3 and the ignition coil 3, 300
A high voltage of up to 400 V is generated, an ultrahigh voltage is further generated on the secondary side of the ignition coil, and the spark plug 4 is discharged. Further, in the embodiment according to the present invention, the ECU 1 is provided with a diagnostic signal transmitting means for transmitting a diagnostic signal to the signal output line 70 when the ignition signal is not transmitted (non-ignition timing).

On the other hand, the feedback circuit 18 is means for feeding back, to the ECU 1 via the signal output line 70, operation information indicating the normal / abnormal state of the high voltage generating circuit. For example, the feedback circuit 18 has a resistor 1
3 and 14, the operation detecting means for detecting the operation information indicating the normal / abnormal state of the high voltage generating circuit, the pulse generating circuit 15 and the NPN transistor 16, and the detected operation information. Based on the signal output line 7
And a canceling means for canceling or canceling the diagnostic signal transmitted to 0. Then, when the high-voltage generating circuit is operating normally, the diagnostic signal transmitted to the signal output line 70 is canceled so that it does not become an ignition signal by mistake.
When there is an abnormality, the diagnostic signal is used to consequently propagate the operation information indicating the intended normal / abnormal state to the engine control unit side via the signal output line 70.

The diagnostic circuit 17 is means for diagnosing the operation of the high voltage generating circuit based on the above-mentioned operation information. For example, the diagnostic circuit 17 includes a change detection unit that detects an electrical change that occurs depending on the presence or absence of cancellation of the diagnostic signal, and a fault diagnosis unit that performs a fault diagnosis of the high voltage generation circuit based on the electrical change. . These diagnostic signal transmitting means, operation detecting means, canceling means, change detecting means, and failure diagnosing means will be described later. In this embodiment shown in FIG. 1, since the microcomputer of the ECU 1 can also be used, the diagnostic circuit 17 is configured in the ECU 1.
Similarly, the feedback circuits 18 configured in the ignition device 2 may be separately provided.

FIG. 12 is a diagram showing the structure of a conventional ignition system. 1 is a configuration of an ignition system without a diagnostic function according to the present invention. The conventional ignition system is the ECU 100,
The ignition device 200, the ignition coil 3, the ignition plug 4, and the signal output line 70 are included. Comparing FIG. 1 and FIG. 12, it can be said that the ignition system according to the embodiment of the present invention has a configuration in which a feedback circuit 18 and a diagnostic circuit 17 are provided in the conventional ignition system.

FIG. 2 is a diagram showing operation waveforms of the ignition system of FIG. The operation of the ignition system according to the embodiment of the present invention will be described with reference to FIG. First, the base signal (A) of Tr9 and the base signal (B) of Tr10 in the ECU 1 are operated with different signals as shown. That is, the ECU 1 sends the base signal (B) to "LOW" during "b-2" of t3 time by the diagnostic signal sending means that sends the diagnostic signal to the signal output line 70 when the ignition signal is not sent. State.

By the way, when the power transmission 5 is energized only during "b-1" of the base signal (B) of Tr10, a current (C) flows. After the current (C) is cut off, the primary voltage (D) is generated in the collector of the power transmission 5. In the present invention, if the high voltage generating circuit operates normally, the primary voltage (D) is 300 to 400.
The high voltage "d" of v is reached. The high voltage "d", referred to as the flyback voltage, is used to output the cancellation signal described below. In order to use a high voltage as a trigger signal, R1
The voltage is divided by 3, 14 and taken into the pulse generation circuit 15. Using the trigger signal as a trigger, the pulse generation circuit 15 outputs an output signal (E) as a cancellation signal for a predetermined time of t4. That is, the operation information is a signal detected from the flyback voltage generated in the high voltage generation circuit based on the ignition signal.

The output signal (E) and the diagnostic signal between "b-2" cause the voltage at the point (F) to be a characteristic of the present invention. That is, as a result, the operation information indicating the intended normal / abnormal state is propagated to the engine control unit side via the signal output line 70.
The voltage at point (F) generates a diagnostic signal "f-2" for diagnosis in addition to the original ignition signal "f-1". The t1 time in the (A) signal is set to be t1> (t2 + t3) with respect to the t1 and t2 times in the (B) signal.
Furthermore, the relationship with t4 time in the output signal (E) signal is
It is set so that t4> t1 and (t2 + t3). However, t1, t2, and t3 are times set separately by the program software in the ECU 1. Further, the reference position of each signal is, for example, when the ignition signal “f-1” is H
The point P, which is IGH → LOW, is used.

The generation principle of f-2 is as follows. In the base signal (B), Tr10 controlled by the pulse signal of "b-1" is OFF during t0, and then Tr9 is
Since it is ON, the power transmission 5 of the ignition device 2
An ignition signal such as "f-1" is input via the signal output line 70. The base signal (B) is in the “HIGH” state for t2 hours after the t0 time which is the “LOW” state, and during this period, the Tr10 is turned on to shut off the power transmission 5. At this time, the voltage at the point (F) during the time t2 is fixed to LOW because the current flows from Vcc → Tr9 → R11 → Tr10 (Tr10 is ON).

After that, the diagnostic signal "b" is transmitted.
Since the base signal (B) is in the "LOW" state for t3 time of "-2", Tr10 is turned off and Tr9 is turned on. In this embodiment, the diagnostic signal has the same operation waveform as the ignition signal. It is convenient for the same to have common parts in the program software and the like in the ECU 1. However, it is not always necessary that the signals have the same operation waveform. If the diagnostic signal having the same operation waveform as the ignition signal is transmitted as described above, the ignition signal is output in the normal state.
However, during t4 time including the transmission time t3 of the diagnostic signal, the signal of the output signal (E) is set to HIGH, that is, the cancellation signal as the operation information indicating the normal state is used to turn on Tr16. , The signal for diagnosis is pulled out to the ground. As a result, the base of the power transmission 5 is LO.
Since it becomes W, the ignition signal is not output.

That is, the operation information indicating the normal state of the high voltage generating circuit is detected, and the diagnostic signal transmitted to the signal output line is canceled based on the detected operation information indicating the normal state. Also, it can be said that the step of canceling out is to pull out the diagnostic signal to the ground on the input side of the ignition device. And here, t4> t1
There is a reason why it is set to be (t2 + t3). That is, transmission of the diagnostic signal is stopped while the offsetting step is being performed, in other words, the step of issuing the diagnostic signal may be completed while the offsetting step is being performed. is important.

On the other hand, when Tr16 is turned on by the HIGH signal of the output signal (E), it is the LOW signal of the base signal (B) during t3 during which the diagnostic signal is transmitted.
Current is Vcc → Tr9 → R11 → R12 → Tr16 → G
It flows with ND. As a result, R11 and R in the ECU 1
A voltage Vs is generated at point (F) divided by 12. The voltage signal Vs of "f-2" is a diagnostic signal, and the above explanation is the generation principle of f-2. Then, there is a basis for one of the steps of detecting an electrical change caused by the “presence” of cancellation of the diagnostic signal and the change detecting means. By the way, if the diagnostic signal is sent immediately after the ignition signal is transmitted, the cancellation may not be executed, and the diagnostic signal is transmitted even immediately before the next ignition signal is transmitted. May cause malfunction. Therefore, the diagnostic signal is transmitted at a predetermined time interval T1 or more to prevent malfunction after the ignition signal has been transmitted, and to prevent malfunction before the ignition signal is transmitted. It is desired that the transmission be stopped after leaving an interval of time T2 or more. In FIG. 2, the predetermined time T1 = t2 and the predetermined time T2 = t5. The predetermined time T1 is 0.5 (ms) and the predetermined time T2 is 0.5 (ms) because it is limited by the calculation processing time of the ECU 1 and the like. Further, during the operation of the embodiment, as shown in the figure, the voltage at the point (F) is
A regular ignition signal is output and the voltage signal Vs is output during the "f-2" time. On the other hand, the input part of the ignition device 2
At point (N), since Tr16 is ON, the waveform is normal. That is, the power transmission 5 never outputs anything other than the normal ignition signal.

Next, a fault diagnosis method based on the voltage signal Vs as a diagnosis signal will be described. FIG. 3 is a diagram showing the relationship between the diagnostic signal and the failure mode. As shown in FIG. 3, the voltage of the voltage signal Vs between "f-2" varies depending on the failure state of each component. That is, the voltage Vs ₁ generated in the normal state is Vs ₁ = {Vcc−V _CE (Tr9) −V _CE (Tr
16)} × R12 / (R11 + R12). For example, V _CC = 5V, V _CE ≈0, R11 = 80Ω, R12 =
If it is 20Ω, Vs ₁ = 1V. This Vs ₁ corresponds to a normal diagnostic signal generated when the high voltage generating circuit is in a normal operating state. In other words, operation information indicating the normal state of the high voltage generating circuit is transmitted to the engine control via the signal output line. This is the result of being propagated to the unit side. And
The normal diagnosis signal is a predictive value which is given to the failure diagnosis means in advance and stored therein.

When the power transmission 5 is short-circuited, the high voltage generating circuit is abnormal and the primary voltage is high voltage "d".
Is not generated, a canceling signal for a fixed time is not generated in the output signal (E). Due to the operation information indicating the abnormal state in which the cancellation signal is not generated, Tr16 is turned off and the diagnostic signal does not fall to the ground. That is, the operation information indicating the abnormal state of the high voltage generating circuit is detected, and the diagnostic signal transmitted to the signal output line is canceled out based on the detected operation information indicating the abnormal state. Therefore, Vcc →
Tr9 → R11 → R12 → R8 → Powertrain 5 base →
Emitter → via R6, it falls to the ground (GND). As a result, the voltage signal Vs ₂ is Vs ₂ = [{V _CC −V _BE × 2-R
6 × Ic-V _CE (Tr9)} × (R12 + R8) / (R8 +
R12 + R11)] + 2V _BE + R6 × Ic. The voltage signal Vs ₂ is clearly different from the voltage signal Vs ₁ described above.

Then, there is another reason for detecting the electric change caused by the cancellation of the diagnostic signal and the change detecting means.

For example, V _CC = 5V, V _BE = 0.1V, R
8 = 20Ω, R11 = 80, R12 = 30Ω, V _CE ≈0
V, R6 = 0.1Ω, Ic = 1A (Ic is the ignition coil 3
Since there is a time constant at the rise of the primary current due to the effect of, it depends on the set time of t ₃ but it is set to about 1 A) Vs
₂ = (5V-1.4V-0.1V) x 50Ω-130Ω +
It becomes 1.4V + 0.1V≈2.85V. This Vs ₂ is
Corresponds to an abnormality diagnosis signal generated when the high voltage generation circuit is in an abnormal operating state, in other words, operation information indicating an abnormal state of the high voltage generation circuit is propagated to the engine control unit side via the signal output line. It is the result. The deviation between Vs ₁ and Vs ₂ is an electrical change that occurs depending on the presence or absence of cancellation of the diagnostic signal. Therefore, here is the basis of the step of executing the fault diagnosis of the high-voltage generating circuit from the comparison between the stored normal diagnostic signal and the detected detected diagnostic signal, that is, the electrical change, and the fault diagnostic means. .

Similarly, when the power transmission 5 opens and indicates an abnormal state, Vs ₃ = [{V _CC -V _BE × 2-V
_CE (Tr9) -R6 × _IE } × (R12 + R8) / (R8 + R
12 + R11)] + 2V _BE + R6 × _IE . Where I
_E is a small current of several tens (mA), so R6 = 0.1Ω
The product of and becomes almost 0. If the numerical values of V _CC , V _BE, etc. are the same as above, Vs ₃ = (5V-1.4V) × 50
Ω / 130Ω + 1.4V≈2.78V. further,
Similarly, when the coil is short-circuited or open, Vs ₂ = Vs ₄ and Vs ₃ = Vs ₅ are obtained. Since the voltage is different from the voltage Vs _{1 in the} normal state, the failure can be diagnosed by determining these voltage values by the diagnostic circuit 17.

FIG. 4 is a diagram showing an embodiment of the feedback circuit 18 of FIG. The detailed description will be given together with the description of FIG. 7 described later. FIG. 5 shows the feedback circuit 1 of FIG.
It is a figure which shows the Example which incorporated 8 into the ignition device 2. FIG.
The feedback circuit built-in ignition device 19 in which the feedback circuit 18 is incorporated in the ignition device 2 shown in (1) is specifically configured by a one-chip integrated circuit (semiconductor device). At this time, the capacitor 24 shown in FIG. 5 has a larger integrated circuit when incorporated into one chip, and therefore only this capacitor portion can be externally attached. Further, although the V _CC terminal is provided in the embodiment of FIG. 4, as in the embodiment of FIG. 5, a constant voltage circuit including a resistor 50, a capacitor 51 and a zener diode 52 is incorporated in one chip, It is also possible to provide a V _B terminal.

FIG. 6 is a diagram showing operation waveforms of the ignition device 2 of FIG. The operation will be further described with reference to FIGS. 5 and 6. The primary voltage (I) generated when the secondary current (H) is cut off is taken in by the ECU input signal (G). R36, 37
The signal (J), which has a constant voltage by the voltage dividing Zener diode 35, turns on the Tr 34 via the diode 33. When the Tr 34 is turned on, the capacitor 24 is discharged like “k−1”. That is, it is reset by the primary voltage. After that, the capacitor 24 is charged up again like “k−2”. At that time, the charge-up speed of the capacitor 24 is determined by the current controlled by the current mirror circuit 20 and the capacity of the capacitor 24. By comparing the charged-up potential and the reference voltage (L) by the comparator 27, the signal (M) for a fixed time is output as a pulse signal for t4 hours.

FIG. 7 is a diagram showing the structure of an ignition system according to another embodiment of the present invention. 1 shows a configuration of an ignition system in the case of outputting a pulse signal as a canceling signal by using a drop voltage generated at the time of energization in a current detection low resistance 6 for detecting a primary side current of an ignition coil 3. Is. That is, the signal detected from the drop voltage generated in the current detecting low resistance of the high voltage generating circuit based on the ignition signal is used as the operation information. In addition,
FIG. 7 shows a circuit configuration of another embodiment of a feedback circuit built-in ignition device in which the ignition device 2 and the feedback circuit 18 are integrated.

FIG. 8 is a diagram showing the construction of a power transmission integrated ignition coil with a built-in feedback circuit. As an electric power distribution system of the independent ignition type, there is a power transmission integrated ignition coil in which the ignition device 2 and the ignition coil 3 are integrated. 1 shows an embodiment of a feedback circuit built-in power transmission integrated ignition coil 45 in which a feedback circuit 18 is built in and integrated with the power transmission integrated ignition coil. The power transmission integrated ignition coil 45 with a built-in feedback circuit is an ignition coil of a type housed in a plug hole provided in a cylinder block of an engine.

Generally, in the ignition coil of the type housed in the plug hole, the connection terminal to the outside on the ignition plug side is provided independently. Power-feeder integrated ignition coil 4 with a built-in feedback circuit configured as shown
5, the external connection terminals are the power supply side (V _B ),
There are four on the ECU side, the ground side (GND), and the spark plug side. In this embodiment, the integral package simplifies the internal wiring by sharing the necessary power source and ground between the feedback circuit 18 and the ignition device 2 or the ignition coil 3. Also, since the connection part (coil side) between the collector of the power transmission 5 and the ignition coil 3 is also performed in the integrated package, at least three external connection terminals are provided except for the independently provided ignition plug side. This eliminates unnecessary connection terminals. Further, by directly grounding the main body of the power transmission integrated ignition coil 45 with a built-in feedback circuit at the time of mounting, it is possible to omit the ground side (GND) connection terminal.

This not only simplifies the internal wiring of the integrated ignition coil, but also simplifies the wiring on the vehicle side. That is, there is an advantage that the existing wiring can be used as it is. It should be noted that if the ignition coil 3 and the ignition device 2 are configured separately, it is necessary to draw the power source V _B into the ignition device 2, so that one connecting terminal is provided as compared with the conventional ignition device or ignition system having no diagnostic function. Because it will increase,
It goes without saying that the present embodiment in which the ignition coil and the ignition device are integrated is effective.

FIG. 9 is a diagram showing an example of a package in which a feedback circuit is formed in the ignition device. Resin case 4
0, and a plurality of terminals 43 insert-molded therein,
It is composed of a metal base 42, a power transmission laminated portion 39, a hybrid IC 38, and a plurality of connecting wires 41. Then, in the hybrid IC 38, the feedback circuit 1 is provided together with the current control circuit 7 of the ignition device 2 and the like.
8 are included. That is, the means for feeding back the operation information is built in the ignition device and configured in one integrated circuit. In this embodiment, simplification and downsizing can be achieved.

FIG. 10 shows the hybrid IC 38 and the power transmission laminated portion 39 of FIG. 9 as a one-chip power module 44.
It is a figure which shows the example of a package comprised by. That is, the means for feeding back the operation information is configured as a one-chip semiconductor device together with the ignition device. In this embodiment, the plurality of connecting wires 41 and the like are eliminated, and further,
There are advantages of simplification and miniaturization.

FIG. 11 is a sectional view showing the structure of the power transmission integrated ignition coil with a built-in feedback circuit of FIG.
It shows a specific example in which the ignition device 2, the feedback circuit 18, and the ignition coil 3 are integrally packaged. An iron core 60, a primary coil 61, and a secondary coil 62, which are components of the ignition coil 3, are arranged in an outer case 55, and the ignition device 5 according to the present invention shown in FIG. 9 or 10 is arranged.
It is integrated with 8 and is sealed with an insulating resin 59. Further, the ignition device section and the ignition coil section are connected to each other by a power line 56.
And a primary line 57 for connection. Although the connector 55a is shown as being integrated with the outer case 55 in the figure, the connector 55a may be integrated with the ignition device.

[0037]

According to the present invention, in the ignition system, a dedicated signal line for diagnosis or a dedicated terminal is not provided (for example, without increasing the number of input / output pins between the ECU 1 and the ignition device 2 or the number of connection points). ) Moreover, it becomes possible to add a failure diagnosis function by diverting the existing existing connector or harness. This enables downsizing and simplification of the harness. Further, there is an advantage that replacement and replacement with the conventional ignition system can be easily performed, that is, an ignition system with a failure diagnosis function having excellent versatility can be provided.

[Brief description of drawings]

FIG. 1 is a diagram showing a configuration of an ignition system according to an embodiment of the present invention.

FIG. 2 is a diagram showing operating waveforms of the ignition system of FIG.

FIG. 3 is a diagram showing a relationship between a diagnostic signal and a failure mode.

FIG. 4 is a diagram showing an embodiment of the feedback circuit of FIG.

5 is a diagram showing an embodiment in which the feedback circuit of FIG. 4 is incorporated in an ignition device.

6 is a diagram showing operation waveforms of the ignition device 2 of FIG.

FIG. 7 is a diagram showing a configuration of an ignition system of another embodiment according to the present invention.

FIG. 8 is a diagram showing a configuration of a power transmission integrated ignition coil with a built-in feedback circuit.

FIG. 9 is a diagram showing an example of a package in which a feedback circuit is configured in the ignition device.

10 is a diagram showing an example of a package in which the hybrid IC of FIG. 9 and a power transmission laminated portion are configured by a one-chip power module.

11 is a cross-sectional view showing the configuration of the power transmission integrated ignition coil with a built-in feedback circuit of FIG.

FIG. 12 is a diagram showing a configuration of a conventional ignition system.

[Explanation of symbols]

1 ... ECU, 2 ... Ignition device, 3 ... Ignition coil, 4 ... Ignition plug, 5 ... Power transmission 6 ... Low resistance for current detection, 7 ... Current control circuit, 8, 11, 12, 13, 14, 2226, 2
8, 30, 32, 36, 37 ... Resistance, 7 ... Current control circuit, 9, 25 ... PNP transistor, 10, 16, 2
3, 29, 31, 34 ... NPN transistor 15 ... Pulse generation circuit, 17 ... Diagnostic circuit, 18 ... Feedback circuit, 19 ... Feedback circuit built-in ignition device, 20 ...
Current mirror circuit, 21, 33 ... Diode, 24 ...
Capacitor, 27 ... Comparator, 35 ... Zener diode 38 ... Hybrid IC, 39 ... Power transmission laminated part, 40 ... Resin case, 41 ... Connection wire, 42 ... Metal base, 43 ... Terminal, 44 ... 1-chip power module 45 ... Feedback Circuit integrated power transmission ignition coil, 50 ... Resistor, 51 ... Capacitor, 52 ... Zener diode, 55 ... Exterior case, 55a ... Connector 56
... power line, 57 ... primary line, 58 ... ignition device according to the present invention, 59 ... insulating resin 60 ... iron core, 61 ... primary coil,
62 ... Secondary coil, 70 ... Signal output line, 100 ... Conventional ECU, 200 ... Conventional ignition device, ... Power supply side, ... E
CU side, ground side, coil side, spark plug side

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Noboru Sugiura 2520 Takaba, Hitachinaka City, Ibaraki Prefecture Hitachi Ltd. Automotive Equipment Division

Claims (12)

[Claims] 1. A high voltage generating circuit comprising an ignition device and an ignition coil is operated to generate a high voltage based on an ignition signal transmitted from an engine control unit via a signal output line, and the high voltage generating circuit The ignition system is characterized in that operation information indicating a normal / abnormal state is fed back to the engine control unit via the signal output line, and a failure diagnosis of the operation of the high voltage generation circuit is performed based on the operation information. Failure diagnosis method. 2. An ignition signal is intermittently transmitted from an engine control unit to an ignition device via a signal output line,
Operating a high voltage generating circuit composed of the ignition device and an ignition coil based on the ignition signal; transmitting a diagnostic signal to the signal output line when the ignition signal is not transmitted; A step of detecting operation information indicating a normal / abnormal state of the voltage generating circuit; a step of canceling or canceling the diagnostic signal transmitted to the signal output line based on the detected operation information; A method for diagnosing a fault in an ignition system, comprising: a step of detecting an electrical change caused by the presence or absence of the cancellation of a service signal; and a step of executing a fault diagnosis of the high voltage generation circuit from the electrical change. . 3. The ignition system according to claim 1, wherein the operation information is a signal detected from a flyback voltage generated by the high voltage generating circuit based on the ignition signal. Fault diagnosis method. 4. The operation information according to claim 1, wherein the operation information is a signal detected from a drop voltage generated by a low resistance for current detection of the high voltage generation circuit based on the ignition signal. Characteristic ignition system failure diagnosis method. 5. The method for diagnosing a failure in an ignition system according to claim 2, wherein the step of canceling is to pull out the diagnostic signal to ground at the input side of the ignition device. 6. The method of diagnosing a failure in an ignition system according to claim 2, wherein transmission of the diagnostic signal is stopped while the canceling step is being executed. 7. The diagnostic signal according to claim 2, for preventing malfunction after the transmission of the ignition signal is completed,
Ignition characterized by being transmitted at intervals of a predetermined time T1 or more, and being stopped after a predetermined time T2 or more to prevent malfunctions before the ignition signal is started to be transmitted. System failure diagnosis method. 8. The fault diagnosis method for an ignition system according to claim 7, wherein the predetermined time T1 is 0.5 (ms) and the predetermined time T2 is 0.5 (ms). 9. An ignition signal transmitted from the engine control unit via an engine control unit, an ignition device, a signal output line connecting the engine control unit and the ignition device, and an ignition coil. Based on the above, in an ignition system that operates a high voltage generation circuit including the ignition device and the ignition coil to generate a high voltage in the ignition coil, the high voltage generation circuit to the engine control unit via the signal output line. An ignition system comprising: means for feeding back operation information indicating normal / abnormal states of the above; and means for diagnosing a failure in the operation of the high voltage generating circuit based on the operation information. 10. The ignition system according to claim 9, wherein the means for feeding back the operation information is built in the ignition device and configured in one integrated circuit. 11. The ignition system according to claim 9, wherein the means for feeding back the operation information is configured as a one-chip semiconductor device together with the ignition device. 12. The ignition device and the ignition coil constitute an integrated power transmission type ignition coil, and the power transmission type integrated ignition coil incorporates means for feeding back the operation information. Ignition system characterized by that.