JP2006266206A - Ignition device for internal combustion engine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an ignition device for an internal combustion engine solving problems that a spark discharging time T becomes longer and no sufficient time required for ion current detection can be ensured when a general-purpose ignition device of high output energy is used. <P>SOLUTION: The current interruption type ignition device provided with a series circuit composed of a power source, a primary wire ring of an ignition coil, and a switching element, includes a means for connecting a capacitor for temporarily storing a part of counter electromotive force of the primary wire ring of the ignition coil generated in current interruption of the switching element and instantly applying an electric charge of the capacitor to the primary wire ring during or after reversal of the counter electromotive force of the primary wire ring. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

The present invention relates to a high-power energy internal combustion engine ignition device required for a direct fuel injection internal combustion engine that is effective for measures against exhaust gas and fuel consumption, and particularly at least an internal combustion engine by detecting a change in the amount of ions caused by combustion of the internal combustion engine. The present invention relates to an internal combustion engine ignition device that is optimally combined with a combustion state detection device for an internal combustion engine that detects the occurrence of engine misfire and knocking.

Conventionally, an internal combustion engine ignition device has been frequently used as a current interruption type ignition device. However, in order to comply with recent high-compression lean combustion for measures against exhaust gas and fuel efficiency, the energy depending on the form of the discharge current is used. Due to the shortage, double spark igniters, multi-spark igniters or alternating spark igniters have been proposed. On the other hand, the combustion state detection device for an internal combustion engine detects a continuous misfiring and detects a change in the rotational speed of the internal combustion engine at the time of misfiring with a sensor in order to indicate a warning to the operator of the internal combustion engine. A misfire detection function has been proposed.

In addition, the combustion state detection device for an internal combustion engine using an ionic current exhibits excellent misfire detection performance even in a multi-cylinder engine in which the misfire detection accuracy is lowered by the rotation variation method, and can detect misfire for each cylinder. However, since the high energy ignition device generally has a long discharge duration, the ion detection start time is limited, which is incompatible.

FIG. 8 shows a conventional current interruption type internal combustion engine ignition device, and FIG. 9 shows a discharge current waveform of the spark plug of the output.

In the figure, one primary wire ring 101 of the ignition coil 1 is connected to a power source 2 and the other is connected to a switching element 3, which is connected by a primary current control circuit 4 having a connection terminal 7 to an internal combustion engine control ECU. When the switching element 3 is interrupted by the ignition signal of the control circuit, a high voltage is induced in the secondary wire ring 102 of the ignition coil 1, and the ignition plug 6 is shown in FIG. 9 via the diode 5. A spark discharge in the form of a discharge current is performed. Here, the role of the diode 5 is that when the switching element 3 starts energization, the voltage of the power source 2 is applied to the primary wire ring 101 and the voltage is induced to the secondary wire ring 102 by about 1.5 KV. This is provided in order not to cause the spark discharge in the stopper 6.

In FIG. 9, when the turns ratio of the primary wire 101 and the secondary wire 102 of the ignition coil 100 is small, a discharge current in the form of B is obtained when the turn ratio is large. In a direct-injection internal combustion engine or the like that has a relatively large triangular wave and in which strong eddy current combustion is performed, the current in the latter half of the triangular wave hardly contributes to the ignition of the fuel due to the increased turbulence.

FIG. 10 shows an internal combustion engine ignition device shown in FIG. 8 with a conventional internal combustion engine combustion state detection device using an ion current. FIG. 11 shows the form of the ion current. Is a normal ion current detection waveform, (b) is a diagram showing an ion current detection waveform at the time of misfire.

In FIG. 10, a spark plug 6 is connected to the high voltage side of the secondary coil 102 of the ignition coil 100, and a series circuit of a constant voltage diode 8 and a diode 9 is connected to the low voltage side. A series circuit of a resistor 11 and an input terminal of the ion detection circuit 12 is connected in parallel to the capacitor 10 and the diode 9 for constituting an ion detection power source in parallel with the diode 8. Further, the protective diode 13 is connected to the input terminal of the ion detection circuit 12, and the output terminal is connected to the input terminal 14 to the internal combustion engine control ECU.

When the ignition signal of the internal combustion engine is output from the ECU output terminal 7, the switching element 3 cuts off the current, a negative voltage is generated on the high voltage side of the secondary coil 102 of the ignition coil 100, and a spark discharge is generated in the spark plug 6. As a result of the current flowing starting from, charge limited to the constant voltage diode 8 is accumulated in the capacitor 10 via the diode 9. The diode 9 is provided in order to block the voltage when the switching element 3 is turned on and prevent the spark plug 6 from discharging, and the resistance value of the resistor 11 is set sufficiently high as shown in FIG. It has a role of the diode 5 to be operated.

When the spark discharge time T shown in FIG. 11 has passed, the charge voltage of the capacitor 10 is applied to the spark plug 6, so that positive ions of combustion ions caused by combustion in the internal combustion engine due to the spark discharge at the spark plug are generated. Negative ions are collected on the center electrode of the spark plug 6 on the wall of the internal combustion engine, and the ionic current shown in FIG. (A) is detected by the ion detection circuit 12 and input to the ECU via the input terminal 14. Note that the time t when the ion current decreases in the figure is the compression top dead center, and the ion current discrimination is performed mainly after the top dead center. Fig. (B) shows an ion current waveform at the time of misfire.

In recent exhaust gas countermeasures, there is a demand for a system that finely collects information on changes in ion current from the start of the internal combustion engine to the high speed range and controls the air-fuel ratio in combination with EGR. In order to detect combustion deterioration or knocking with ionic current, it has been confirmed that the critical time zone for ionic current discrimination is around 15 degrees after the top dead center or later. On the other hand, in order to cope with a direct fuel injection internal combustion engine with lean fuel, etc., a high output energy ignition device is desired as a problem before control by ion current, but a general purpose high output energy ignition device is desired. When this is used, there has been a problem that the spark discharge time T shown in FIG. 11 becomes long and sufficient time required for ion current detection cannot be taken.

In a general current interruption type ignition device, as shown in paragraph 0006, a slight increase in discharge current can be obtained depending on the turn ratio of the primary wire 101 and the secondary wire 102 of the ignition coil 100. In a direct injection internal combustion engine, etc., in which the discharge current is a relatively large triangular wave in the initial stage and combustion is strong in eddy currents, the current in the latter half of the triangular wave hardly contributes to the ignition of fuel due to the increased turbulence. There is a problem.

Furthermore, when trying to collect detailed information based on the ionic current, in the spark discharge by applying a voltage in one direction of negative discharge at the spark plug 6, the leakage capacitance of the electric circuit mounted with the ignition coil 100 and the spark plug 6 (general In such a mounting state, about 1 to 3 kV of electric charge remains after the end of the spark discharge, and corona discharge occurs during the ionic current detection period, which has emerged as a new problem that hinders the ionic current information.

Therefore, as a high output energy ignition device, the switching element 3 that repeats turn-off and turn-on several times in a short time at the ignition timing cannot solve the above problem. In addition, the AC ignition device can solve the residual charge problem of leakage capacitance by making the end of the discharge output free vibration, but an independent power supply is installed to detect the circuit and the ion current for AC. A complicated circuit configuration is required, such as switching between ignition output and ion current detection.

An internal combustion engine ignition device according to claim 1 of the present invention is a current interruption type ignition device comprising a series circuit of a power source, a primary wire ring of an ignition coil, and a switching element, and an ignition coil generated when the current of the switching element is interrupted. A capacitor for temporarily storing a part of the counter electromotive force of the primary wire ring, and means for instantaneously applying the charge of the capacitor to the primary wire ring during or after the reverse electromotive force of the primary wire ring is inverted. By comprising, the stable spark discharge without the wobbling of the end part of the discharge current which is a fault of the current interruption method can be obtained.

An internal combustion engine ignition device according to a second aspect of the present invention is an ignition device of a current interrupt system comprising a series circuit of a power source, a primary wire ring of an ignition coil and a switching element, and an ignition coil generated when the current of the switching element is interrupted. A capacitor for temporarily storing a part of the counter electromotive force of the primary wire ring is connected, and means for instantaneously applying the charge of the capacitor to the primary wire ring during or after the counter electromotive force of the primary wire ring is inverted is provided. In addition, as a configuration in which the charge discharge oscillation of the capacitor is performed for at least one cycle, a stable spark discharge without wobbling of the end portion of the discharge current, which is a drawback of the current interruption method, is obtained, and at the same time, the secondary coil of the ignition coil This cancels the influence of leakage capacitance between the spark plug and the spark plug.

According to a third aspect of the present invention, there is provided an internal combustion engine ignition device in which the charge of the capacitor of the ignition device according to the first and / or second embodiment is instantaneously applied to the primary wire ring of the ignition coil. The configuration that changes depending on the number is adapted to the operating state of the internal combustion engine.

According to a fourth aspect of the present invention, there is provided an internal combustion engine igniter in which the charge of the capacitor is supplied to the ignition coil from the moment of current interruption of the switching element, which is the ignition timing of the igniter according to the first and second aspects. The timing applied to the primary wheel changes with a gradient within 0.7 ms to 1.5 ms when the rotational speed of the internal combustion engine is 1000 rpm and within 0.5 ms when the rotational speed of the internal combustion engine is 8000 rpm, and is adapted to each rotational range of the internal combustion engine. And sufficient ignition energy can be obtained.

According to a fifth aspect of the present invention, there is provided an internal combustion engine ignition device comprising: an ignition plug connected to the high voltage side of the secondary wire of the ignition coil of the ignition device according to the first and / or second aspect; Further, the combustion ion detection circuit of the internal combustion engine is configured with a detection power source to solve the above-mentioned problems.

An internal combustion engine ignition device according to a sixth aspect of the present invention comprises an ignition plug connected to the high voltage side of the secondary wire of the ignition coil of the ignition device according to the first and / or second aspects, and the low voltage side. Further, the combustion ion detection circuit of the internal combustion engine is configured with a detection power source, and the above-mentioned problems are solved by setting the ion detection start time to about 15 degrees ATDC (after compression top dead center) at least in the practical engine rotation range. is there.

An internal combustion engine ignition device according to a seventh aspect of the present invention comprises an ignition plug connected to the high voltage side of the secondary wire ring of the ignition coil of the ignition device according to the first and second aspects, and the low voltage side. Having at least two constant voltage diodes connected in series in opposite directions to each other, connecting a capacitor in parallel to the one constant voltage diode as a power source, and a combustion ion detection circuit from the series connection point via a resistor To solve the above-mentioned problems.

As described above, according to the present invention, the change information of the ionic current is collected finely from the start of the internal combustion engine, which has been required in recent exhaust gas countermeasures, to the high speed range, and the air-fuel ratio is combined with the EGR. In order to cope with a direct fuel injection internal combustion engine with lean fuel, etc., while ensuring a discrimination time up to about 15 degrees ATDC necessary for detecting a deterioration state of combustion due to ion current and knocking, In addition, an ignition device with high output energy is desired as a problem before control by ion current. However, it is low enough to add an ignition auxiliary capacitor and a switching element such as a diode and SCR to a general-purpose high output energy ignition device. The maximum ignition energy can be secured over a wide range from the rotation speed to the high rotation speed, and at the same time, the leakage key between the secondary wheel and the spark plug In which it is possible to obtain optimum engine ignition device in the ion current control can be solved the Pashitansu charging problem.

Embodiment 1 FIG.
FIG. 1 shows a first embodiment of the present invention described in claims 1 to 4, and FIGS. 2 (a) and 2 (b) show discharge current waveforms at the spark plug 6 of the output of this embodiment. .

8, a diode 15 is connected between the power source and the primary wire ring 101 of the ignition coil 100, and is connected between the secondary wire wheel 102 and the spark plug 6. A constant voltage diode 16 is connected in place of the diode 5 for preventing spark discharge when the switching element 3 is turned on. A series circuit of a capacitor 17, a diode 18 and an SCR 19 is connected in parallel with a series circuit of the primary wire ring 101 and the switching element 3, and the gate of the SCR 19 is connected to an output terminal of the primary current control circuit 7, A connection point between the diode 18 and the SCR 19 is connected to a connection point between the primary wire ring 101 and the switching element 3 via the ignition auxiliary capacitor 20.

A voltage is applied to the primary wire ring 101 by the switching element 3 in response to a turn-on signal from the primary current control circuit 4 to induce a voltage in the secondary wire ring 102. The voltage applied to the spark plug 6 is a constant voltage diode. The voltage does not exceed 16 blocking voltage, or even if it exceeds, the voltage is suppressed to 1 KV or less, and no spark discharge is performed on the spark plug 6. Next, when the primary current is interrupted by turning off the switching element 3, a part of the back electromotive force of the primary wire ring 101 charges the ignition auxiliary capacitor 20 via the diode 18 and at the same time, the secondary wire ring. A high voltage is induced at 102 and spark discharge is started at the spark plug 6 via the constant voltage diode 16.

The spark discharge current is relatively high at several tens of milliamperes immediately after the start, but at the timing when the amount of change in the magnetic flux of the ignition coil 100 is reduced temporarily due to the energy consumption by the spark discharge, the primary current control circuit 4 turns on the gate of the SCR 19 When the signal is sent, the charge of the capacitor 20 is applied again to the primary wire ring 101 via the capacitor 17 having a relatively large capacity compared to the capacity of the capacitor 20, and as shown in FIG. Since the current at the end portion can be increased, an internal combustion engine such as high compression lean combustion can be easily ignited.

The reversal energy of the discharge current of the capacitor 20 is completed in one cycle because the current flows through the diode 18 simultaneously with turning off the SCR 19. Needless to say, the reversal energy of the spark discharge of the capacitor 20 can be changed by inserting a resistor in series with the diode 18 in order to suppress the reversal current or changing the blocking voltage of the constant voltage diode 16.

The transformation energy can be used only for the purpose of discharging the electric charge of the leakage capacitance between the secondary wire 102 of the ignition coil 100 and the spark plug 6.

Of course, when the turn ratio of the primary wire 101 and the secondary wire 102 of the ignition coil 100 is set small and the voltage induced in the secondary wire when the switching element 3 is turned on is less than 1 KV, the diode 5 or While the constant voltage diode 16 is unnecessary, the normal diode 5 can be used when it is desired to completely block the inversion energy of the capacitor 20.

Further, as shown in FIG. 2 (a), the output energy is effectively utilized by increasing the discharge duration during low speed rotation of the internal combustion engine, and the discharge duration is shortened as shown in FIG. 2 (b) during high speed rotation. It is possible to easily control the discharge duration according to the internal combustion engine speed, for example, by controlling the turn-on timing of the SCR 19.

Embodiment 2. FIG.
FIG. 3 shows a second embodiment of the present invention as set forth in claim 1 and claim 2, wherein the turn-on timing of the SCR 19 of the first embodiment is fixed without using the primary current control circuit 4 and simplified. It is what.

3 is the same as that shown in the embodiment of FIG. 1 except that a resistor 21 is connected in series with the diode 18, and a series circuit of a trigger capacitor 22 and a constant voltage diode 23 is connected in parallel with the resistor 21. The connection point between the capacitor 22 and the constant voltage diode 23 is connected to the gate of the SCR 19, a protective resistor 24 and a capacitor 25 are connected between the gate and the cathode of the SCR 19, and the capacitor 17 for power supply is discharged in parallel. A register 26 is connected.

When the switching element 3 is turned off in response to the ignition signal from the primary current control circuit 4, a part of the back electromotive force of the primary wire ring 101 is accumulated in the capacitor 20 via the resistor 21 and the diode 18, and at the same time, the resistor 21. The charge for the voltage drop is started to be charged in the trigger capacitor 22 via the constant voltage diode 23. During this time, a high voltage is generated in the secondary wire ring 102 and spark discharge is started in the spark plug 6 via the constant voltage diode 16.

When the charging current of the capacitor 20 reaches the saturation point, the charge of the capacitor 22 that has been charged at the same time is discharged and applied to the gate of the SCR 19 via the register 21, and when the threshold value is reached, the SCR 19 is turned on. The electric charge of the capacitor 20 is discharged to the primary wire ring 101 through the capacitor 17.

Embodiment 3 FIG.
FIG. 4 is a modified embodiment of the first embodiment of the present invention described in claims 1 to 4 shown in FIG. 1, and is a third embodiment.

The difference from FIG. 1 is that a series circuit of the SCR 19 and the auxiliary ignition capacitor 20 is formed in parallel with the series circuit of the primary wire ring 101 and the switching element 3, and a diode 18 is connected between the connection points of the two series circuits. It is that you are.

When the switching element 3 is turned off in response to the ignition signal of the primary current control circuit 4, a part of the back electromotive force of the primary wire ring 101 is stored in the capacitor 20 via the diode 18 and simultaneously to the secondary wire ring 102. A high voltage is induced to start spark discharge in the spark plug 6 through the constant voltage diode 16. In the vicinity of the end of the spark discharge, a turn-on signal is sent again from the primary current control circuit 4 to the switching element 3, and after the switching element 3 is sufficiently energized, a turn-on signal is sent immediately to the gate of the SCR 19, and the charge of the capacitor 20 is again primary. When applied to the wire ring 101, a discharge current in the direction opposite to the discharge current due to the first current interruption flows through the spark plug 6 via the constant voltage diode 16.

When the discharge of the capacitor 20 is completed, a turn-off signal is sent to the switching element 3 and the switch element 3 is energized slightly longer than the energization time of the SCR 19 to keep the turn-off state until the next normal primary current energization timing. As the switching element 3, another switching element only for forming the discharge path of the capacitor 20 may be used.

The discharge output of the capacitor 20 cancels the charge of the leakage capacitance on the secondary wire ring 102 side of the ignition coil 100 so as not to cause a spark discharge in the reverse direction to the initial discharge due to the blocking voltage of the constant voltage diode 16 or the like. Can only be used.

Embodiment 4 FIG.
FIG. 5 shows a combustion ion detection circuit for an internal combustion engine according to claims 5 to 7, which is a fourth embodiment of the present invention. The discharge duration of the spark discharge current is determined by the rotational speed of the internal combustion engine. The basic discharge waveform is shown in FIG. 6 and the discharge duration characteristic is shown in FIG.

The basic configuration is a combination of FIG. 1 which is the first embodiment and FIG. 10 which has a combustion state detection circuit of an internal combustion engine using conventional ion current, and some differences constitute an ion current detection power source. Instead of the diode 9 for this purpose, a constant voltage diode 28 is used.

When the ignition signal of the internal combustion engine is output from the ECU output terminal 7, the switching element 3 is turned off to cut off the current of the primary wire ring 101, and a part of the back electromotive force of the primary wire wheel 101 is ignited via the diode 18. At the same time as charging the auxiliary capacitor 20, a negative voltage is generated on the secondary wire ring 102 of the ignition coil 100, and a constant voltage diode 28 is generated by the current flowing through the spark plug 6 shown in FIG. The electric charge limited by the constant voltage diode 8 is accumulated in the capacitor 10 via. Subsequently, the primary current control circuit 4 receives the output signal at the timing of the substantially shaded portion that is delayed when the rotational speed of the internal combustion engine shown in FIG. 7 is low and early when the rotational speed is high, and the SCR 19 is turned on. As a result, the electric charge of the capacitor 20 is discharged through the capacitor 17, and at the time of low revolution, the current at the end of the discharge current is added to extend the discharge duration, and at high revolution, the change in the magnetic flux of the ignition coil is converged early. As a result, the discharge time is controlled to be short, and at the same time, the commutation energy of the capacitor 20 is applied via the constant voltage diode 28, thereby charging by the leakage capacitance between the secondary wire 102 of the ignition coil 100 and the spark plug 6. Cancel.

Thereafter, the charge voltage of the capacitor 10 becomes an ion current detection power source, which is subsequently applied to the spark plug 6, and ATDC (after compression top dead center) 15 necessary for obtaining various combustion information regardless of the rotational speed of the internal combustion engine. A change in the ion current with a sufficient degree is taken into the ion detection circuit 12.

In order to effectively detect the ion current information, it is necessary to observe up to about 15 degrees ATDC. For this reason, the ignition discharge time is 0.7 ms to 1.5 ms at an internal combustion engine speed of 1000 rpm, and 0 at 8000 rpm. It is desirable to end the discharge time with a gradient within 5 ms.

Although omitted in the embodiments described so far, in the internal combustion engine ignition device of the present invention, a current limiting circuit configuration is added to the switching element 3, or protection for limiting the back electromotive force of the primary wire ring 101 is provided. Needless to say, elements can be added.

1 is a diagram showing Embodiment 1 of the invention. FIG. The output discharge current waveform figure of Embodiment 1 of invention. The figure which shows Embodiment 2 of invention. The figure which shows Embodiment 3 of invention. The figure which shows Embodiment 4 of invention. The output discharge current waveform figure of Embodiment 4 of invention. The characteristic figure of the rotation speed and discharge time of Embodiment 4 of invention. Conventional current interruption type ignition device. The output discharge current figure of the conventional ignition device. An ignition device having a conventional ion current detection circuit. Ion current detection waveform diagram.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Ignition coil 2 Power supply 3 Switching element 4 Primary current control circuit 5 Diode 6 Spark plug 7 Connection terminal 8 Constant voltage diode 9 Diode 10 Capacitor 11 Register 12 Ion detection circuit 13 Protection diode 14 Input terminal 15 Diode 16 Constant voltage diode 17 Capacitor 18 Diode 19 SCR
20 capacitor 21 register 22 capacitor 23 constant voltage diode 24 register 25 capacitor 26 register 28 constant voltage diode 100 ignition coil 101 primary wire ring 102 secondary wire ring

Claims (7)

In a current interruption type ignition device composed of a series circuit of a power source, a primary coil of an ignition coil and a switching element, a part of the back electromotive force of the primary coil of the ignition coil generated when the current of the switching element is interrupted is temporarily An internal combustion engine ignition device comprising: a capacitor to be connected; and means for instantaneously applying a charge of the capacitor to the primary wheel during or after the reverse electromotive force of the primary wire is reversed. In a current interruption type ignition device composed of a series circuit of a power source, a primary coil of an ignition coil and a switching element, a part of the back electromotive force of the primary coil of the ignition coil generated when the current of the switching element is interrupted is temporarily A capacitor for storing, and means for instantaneously applying the capacitor charge to the primary ring during or after the back electromotive force of the primary ring is reversed. An internal combustion engine ignition device characterized by the above. 3. The internal combustion engine ignition device according to claim 1, wherein a timing at which the electric charge of the capacitor is instantaneously applied to the primary wire ring of the ignition coil varies depending on the rotational speed of the internal combustion engine. . From the moment when the current of the switching element is cut off, which is the timing of ignition, the timing at which the charge of the capacitor is applied to the primary coil of the ignition coil is 0.7 ms to 1.5 ms when the engine speed is 1000 rpm, and 0 when the engine speed is 8000 rpm. 3. The internal combustion engine ignition device according to claim 1, wherein the internal combustion engine ignition device changes with a gradient within 5 ms. 3. An ignition plug is connected to the high voltage side of the secondary wire ring of the ignition coil, and a combustion ion detection circuit of the internal combustion engine is configured with a detection power source on the low voltage side. The internal combustion engine ignition device according to claim. An ignition plug is connected to the high voltage side of the secondary coil of the ignition coil, and the combustion ion detection circuit of the internal combustion engine is configured with a detection power source on the low voltage side, and the ion detection start time is set to ATDC (at least in the practical engine rotation range). The internal combustion engine ignition device according to claim 1 and / or 2, characterized by being about 15 degrees (after compression top dead center). An ignition plug is connected to the high voltage side of the secondary coil of the ignition coil, and at least two constant voltage diodes connected in series in opposite directions to each other on the low voltage side, and in parallel with the one constant voltage diode 3. The internal combustion engine ignition device according to claim 1, wherein a capacitor is connected to serve as a power source, and is connected to a combustion ion detection circuit through a resistor from the series connection point.

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