JP3142437B2 - Ignition device for internal combustion engine - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ignition device for an internal combustion engine which can detect an abnormality such as disconnection or short circuit of an ignition coil in the ignition device.

[0002]

2. Description of the Related Art FIG. 8 is a circuit diagram partially showing a conventional ignition device for an internal combustion engine. In the drawing, 1 is a rotor attached to an engine (not shown) which is an internal combustion engine, 2 is a pickup for detecting a projection 1a of the rotor 1 and converting it into an electric signal, and 3 is a waveform shaping of an output signal of the pickup 2 A waveform shaping circuit, 4 an ignition signal generating circuit for determining an energizing timing and an ignition timing based on an output signal of the pickup 2 and outputting an energizing signal and an ignition signal, 5 a battery mounted on a vehicle, 6 an ignition signal generating A transistor 7 for turning on and off a semiconductor switching element, which will be described later, based on an output signal of the circuit 4, turns on and off with the inversion of the transistor 6, and an ignition coil 8
The above-mentioned semiconductor switching element is composed of a power transistor for connecting or disconnecting the battery 5 and for turning on and off the ignition coil 8.

Next, the operation of the conventional ignition device for an internal combustion engine will be described. The pickup 2 detects the rotation of the rotor 1 and outputs it as an electric signal. The waveform shaping circuit 3 shapes the electric signal and inputs it to the ignition signal generating circuit 4. The ignition signal generation circuit 4 predicts the energization and ignition time of the ignition coil 8 using the input electric signal as a reference signal, and turns on and off the semiconductor switching element 7 via the transistor 6 to turn the ignition coil 8 on the battery 5. To the energized state and the interrupted state.

[0004]

Since the conventional ignition device for an internal combustion engine is configured as described above, ignition by the ignition coil 8 is not performed at the time of a failure, but at this time, the pickup 2 fails. It is not known whether the ignition signal generation circuit 4 has failed or the ignition coil 8 has failed. Therefore, in the conventional ignition device for an internal combustion engine, even if the ignition coil 8 becomes abnormal such as disconnection or short circuit, it cannot be determined immediately. (Parts) can be understood, and therefore, there is a problem that repair requires time and effort.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and it is possible to immediately determine whether an ignition coil has become abnormal, and to repair the ignition coil quickly and without hassle. The aim is to get the device.

[0006]

Means for Solving the Problems] ignition device for an internal combustion engine according to the present invention, the ignition signal, on a switching element is turned off, the ignition coil current is blocked by the switching element, the ignition coil when energized, or the by monitoring the terminal voltage of the switching element during blocking and means for detecting an abnormality of the ignition coil, the switching element
The timing of monitoring the terminal voltage of the
Switch the switching element from on to off or from off to on.
It is just before the replacement .

[0007]

[0008]

[0009]

According to the ignition device for an internal combustion engine according to the present invention ,
By monitoring the terminal voltage of the switching element,
It is possible to detect whether the ignition coil is short-circuited or disconnected. Also detects an abnormality when the non-detection signal is stable
Therefore, stable and reliable detection can be performed.

[0010]

[0011]

[0012]

[Embodiment 1] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a circuit diagram partially showing a first embodiment of the present invention by blocks. In the figure, the same objects as those in FIG. 8 are denoted by the same reference numerals. Reference numeral 9 is connected between the ignition coil 8 and the semiconductor switching element 7, and monitors the terminal voltage of the semiconductor switching element 7 when the ignition coil 8 is energized or de-energized to detect an abnormality such as a short circuit or a disconnection of the ignition coil 8. The detection circuit 10 as a means for performing the operation is a warning light for notifying the abnormal state of the ignition coil 8 when the ignition coil 8 is abnormal.

FIG. 2 is a waveform diagram showing when the ignition coil 8 is normal. In FIG. 2, (A) and (B)
(C) and (D) show the signal waveforms at points A, B, C, and D in FIG. 1, respectively.
(B) is an ignition signal which is an output of the ignition signal generation circuit 4,
(C) is a primary waveform which is a voltage signal between the ignition coil 8 and the semiconductor switching element 7, and (D) is a detection signal which is an output signal of the detection circuit 9. (E)
Indicates the detection timing. The ignition signal generation circuit 4 performs ignition prediction based on the front signal a which is the output signal of the pickup 2, and performs energization prediction based on the rear signal b. The ignition signal generation circuit 4 generates a signal at the time of ignition prediction based on the pickup signal, and lowers the signal at the time of power supply prediction to generate an ignition signal shown in FIG. With the rise of the ignition signal, the transistor 6 is turned on, the semiconductor switching element 7 is turned off, and the ignition coil 8 generates a spark at the ignition plug 8a. At this time, the primary waveform shown in FIG. In addition, the falling of the ignition signal turns off the transistor 6, turns on the semiconductor switching element 7, and energizes the ignition coil 8. At this time, the primary waveform falls.

In contrast to the above-mentioned primary waveform (C), the detection signal (D), which is the output signal of the detection circuit 9, includes a resistor 9a, a zener diode 9b, and a capacitor 9c when the primary waveform vibrates near the time of ignition prediction. With the action
The voltage of the capacitor 9c storing the positive-side charge gradually increases in a stepwise manner, and becomes a stable and flat voltage before energization is predicted. Further, the detection signal sharply falls due to the fall of the primary waveform at the time of energization prediction, and thereafter, the flatness is maintained until the ignition prediction.

The detection timing shown in (E) indicates when a short circuit of the ignition coil 8 is detected and when a disconnection is detected. The short circuit is detected when the ignition coil 8 is energized, and the disconnection is detected when the ignition coil 8 is not energized. Is performed immediately before Here, the reason why the timing is set immediately before the ignition prediction is that the primary waveform is considered to be sufficiently stable at this time, as described above. The disconnection is detected immediately before the ignition coil 8 is energized.

FIG. 3 is a waveform diagram showing a case where the ignition coil 8 is disconnected halfway. In FIG. 3, (A)
(B), (C) and (D) are the same as FIG.
The signal waveforms at points B, C and D are shown. As is apparent from this figure, if the ignition coil 8 is disconnected at the time point G, the primary waveform (C) and the detection signal (D) fall to the ground level at that time, and the levels continue thereafter. Therefore, at the time of disconnection detection, a signal that should be detected at a high level is detected at the ground level, so that it can be determined that there is an abnormality, that is, that the ignition coil 8 has been disconnected. As a result, the warning light 10
Is turned on, off or flashing to notify the driver of the disconnection of the ignition coil 8. In this case, in the detection of a short circuit, a signal having the same level as that of a signal in a normal state is obtained, so that no abnormality is detected.

FIG. 4 is a waveform diagram showing a case where the ignition coil 8 is short-circuited halfway. In FIG. 4, (A)
(B), (C) and (D) are the same as FIG.
The signal waveforms at points B, C and D are shown. As is apparent from this figure, if the ignition coil 8 is short-circuited at the point H, the primary waveform (C) and the detection signal (D) go high at that point, and the levels continue thereafter.
Therefore, when a short circuit is detected, a signal that should be detected at the ground level is detected at a high level, and therefore, it can be determined that an abnormality has occurred, that is, the ignition coil 8 has been short-circuited. As a result, the warning light 10 is turned on, turned off, or blinked to notify the driver that the ignition coil 8 is short-circuited. In this case, in the disconnection detection, a signal having the same level as that of a normal signal is obtained, so that no abnormality is detected. Therefore, in addition to the above description, according to the present embodiment, the abnormality of the ignition coil 8 can be determined by distinguishing between a short circuit and a disconnection.

The operation of this embodiment will be described below with reference to the flowcharts of FIGS. FIG. 5 is a flowchart showing an operation for predicting and determining the energization time and the ignition time. This flowchart is executed when a negative wave and a positive wave of the pickup waveform are generated by an input capture interrupt. The time of the negative wave is the timing for predicting and calculating the ignition time, and the time of the positive wave is the timing for predicting and calculating the energization time. First, in step S1, it is determined based on the pickup signal whether or not it is time to predict and calculate the ignition time. And
If it is not the timing for predicting the ignition time, that is, if it is a positive wave, it is determined in step S2 whether it is the timing for predicting and calculating the energization time, and if not, the process returns to step S1. If it is determined in step S2 that it is time to perform a predictive calculation of the energization time, that is, if it is a positive wave, the process proceeds to step S3 to predict and calculate the energization time for the pickup signal (reference angular position).
Next, in step S4, a predetermined time is subtracted from the calculated energization time to calculate a disconnection detection time, and this value is set in a timer (not shown). This fixed time is the time required for failure detection, and corresponds to a processing time of 20 to 30 steps in the case of microcomputer processing, and is generally 40 to 60 μsec. This time has the same value when calculating a short-circuit detection time described later.

On the other hand, if it is determined in step S1 that it is the timing for predicting and calculating the ignition timing, then in step S5, the prediction and calculation of the ignition timing to be set for the pickup signal (reference angular position) is performed. Then, in step S6, a predetermined time (40 to 60 sec) is subtracted from the calculated ignition timing to calculate a short-circuit detection time, this value is set in a timer, and a series of processing ends.

FIG. 6 is a flowchart showing the timer process. This flowchart is performed after the elapse of the time set by the timer in FIG. First, step S101
Is determined based on the value of the timer. This ignition timing is determined after determining whether or not the ignition coil 8 is short-circuited.
Is performed based on the value set in the timer. If it is not the ignition timing, the process proceeds to step S102, and it is determined whether it is the energization timing. This energization timing is determined based on the value set in the timer in step S107 described later after determining whether or not the ignition coil 8 is disconnected.

If it is not the power-on time, step S103
In step S104, it is determined whether or not the current time is the pre-ignition time set in FIG. 5. If it is not the pre-ignition time, it is determined in step S104 whether or not the current is the pre-energization time also set in FIG. If it is not the time before energization, step S1
01, the process proceeds to step S105 in the case of the pre-energization time, and the detection signal is checked.
At 07, the above-described energization timing is set in the timer, and the process returns to step S101.

If the detection signal is at the ground level in step S105, it is determined in step S108 that the ignition coil 8 is disconnected, and the flow advances to step S109, where a warning is displayed.

On the other hand, if it is determined in step S101 that the ignition timing has been reached, the process proceeds to step S110, in which ignition is performed. If it is determined in step S102 that the current is to be supplied, the process proceeds to step S111, in which power is supplied, and the process returns to step S101. .

If it is determined in step S103 that it is the pre-ignition time, the flow advances to step S112 to check the detection signal.
Then, the ignition timing is set in step S114.

If it is determined in step S112 that the detection signal is at the high level, it is determined in step S115 that the ignition coil 8 is short-circuited, and the flow advances to step S116, where a warning is displayed. After the warning is displayed, the process returns to step S101.

[0026] In order to avoid that the primary waveform is fault detection in an unstable region, but so as to fault detection immediately before the ignition prediction or during energization prediction, the primary waveform as shown in FIG. 7 Failure detection may be performed after the unstable region ends. The unstable region of a general ignition coil is 1 to 2 msec during ignition and 1 ms when energized.
It is the time of the ec rank.

[0027]

[0028]

The ignition device for an internal combustion engine according to the present invention comprises:
The ignition signal, on, off the semiconductor switching element, an ignition coil is cut off energization, by this switching element, the time of ignition coil current, or the ignition coil by monitoring the terminal voltage of the switching element during shutoff Means for detecting abnormalities in the terminal of the switching element.
The timing for monitoring the pressure is determined by controlling the switching element.
To switch from on to off or off to on
Since the ignition coil is short, it is possible to detect an abnormality whether the ignition coil is short-circuited or disconnected, so that the user can easily recognize the case where the ignition coil is abnormal, so that a repair can be performed. Has the effect of being simplified. Non-detection signal is stable
Abnormalities can be detected when
And reliable detection can be performed.
I do.

[0029]

[0030]

[Brief description of the drawings]

FIG. 1 is a circuit diagram showing Embodiment 1 of the present invention.

FIG. 2 is a normal time chart showing the operation of the first embodiment.

FIG. 3 is a time chart showing the operation of the first embodiment at the time of disconnection.

FIG. 4 is a time chart at the time of a short circuit showing the operation of the first embodiment.

FIG. 5 is a flowchart showing an operation for predicting and determining the energization time and the ignition time.

FIG. 6 is a flowchart showing a timer process.

FIG. 7 is a normal time chart showing another operation example .

FIG. 8 is a circuit diagram showing a conventional ignition device for an internal combustion engine.

[Explanation of symbols]

1 rotor, 2 pickup, 4 ignition signal generation circuit, 7 semiconductor switching element, 8 ignition coil, 9 detection circuit, 10 warning light.

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) F02P 3/04 F02P 17/12

Claims (1)

(57) [Claims] An ignition device for an internal combustion engine, comprising: a switching element that is turned on and off by an ignition signal; and an ignition coil that is energized and deenergized by the switching element, wherein the ignition coil is energized or deenergized. comprising means for detecting an abnormality of the ignition coil by monitoring the terminal voltage of the switching element, to monitor the terminal voltage of the switching element timing
Switching the switching element from on to off;
Is an ignition device for an internal combustion engine immediately before switching from off to on .