JP2019152126A - Ignition control device - Google Patents

Abstract

To provide an ignition control device capable of improving ignitability to mixture gas while suppressing the deterioration of electrodes.SOLUTION: An ignition device has a spark plug and an ignition coil. The spark plug has a center electrode and a ground electrode. An engine ECU performs ignition control processing for the operation control of the ignition device. In the ignition control processing, plasma determination processing is performed for determining whether plasma is generated or not in a combustion chamber at a timing before arc discharge is generated with an ignition signal. The plasma determination processing includes Steps S202, S203 of determining that engine operation is in a high load state and engine warming-up operation is finished, and if so, Step S207 of carrying out determination voltage application to the electrodes. It further includes Step S208 of determining whether discharge is generated or not between the electrodes by the determination voltage application.SELECTED DRAWING: Figure 8

Description

  The disclosure herein relates to an ignition control device.

  As an ignition device that ignites a mixed gas in a combustion chamber by generating a discharge in a combustion chamber of an internal combustion engine, for example, in Patent Document 1, after generating a plasma atmosphere in a combustion chamber, arc discharge is performed on the plasma atmosphere. A technique of generating is disclosed. This ignition device has a main electrode that generates an arc discharge when a voltage is applied, and an auxiliary electrode that generates a plasma atmosphere when a voltage is applied. In Patent Document 1, arc discharge is likely to occur due to a plasma atmosphere, so that the mixed gas can be reliably ignited.

JP 2007-32349 A

  However, even when a plasma atmosphere is generated, the phenomenon that ions generated in the combustion chamber collide with the electrode remains the same as when arc discharge occurs. For this reason, when a plasma atmosphere is generated each time an arc discharge is generated, there is a concern that the electrode for generating the plasma atmosphere is gradually deteriorated by repeated collisions of ions.

  A main object of the present disclosure is to provide an ignition control device that can improve the ignitability of a mixed gas while suppressing deterioration of an electrode.

In order to achieve the above object, the disclosed aspect is:
It has electrodes (11, 12) to which a voltage is applied. By applying a voltage to the electrodes, a discharge can be generated in the combustion chamber (200) of the internal combustion engine, and the gas mixture in the combustion chamber is ignited by the discharge. An ignition part (10);
A voltage application unit (20) for applying a voltage to the electrodes;
An ignition control device (24) for controlling the operation of the ignition device (100) comprising:
A first execution unit (S108) that causes the voltage application unit to execute voltage application to the electrodes in order to generate discharge in the ignition unit;
The voltage application unit is configured to generate a plasma in the combustion chamber by ionizing the gas mixture so that the plasma is present in the combustion chamber when voltage application is performed by the first execution unit. A second execution unit (S107) to be executed,
A third execution unit (S207) for causing the voltage application unit to execute voltage application to the electrode in order to acquire a discharge state by the ignition unit;
A second execution determination unit (S103, S208) for determining whether to execute voltage application by the second execution unit based on a discharge state by the ignition unit when voltage application by the third execution unit is executed;
Is an ignition control device.

  It is considered that the discharge state by the ignition part when a voltage is applied to the electrode of the ignition part changes according to the deterioration state of the electrode. In addition, when the electrode is not deteriorated, discharge is likely to occur with the application of voltage to the electrode, and as the electrode deteriorates, the discharge is gradually generated with the application of voltage to the electrode. It is thought that it will become difficult.

  Therefore, according to the above aspect, the case where the plasma atmosphere is generated and the case where the plasma atmosphere is not generated are selectively used according to the discharge state by the ignition unit when the voltage is applied to the electrode by the third execution unit. For this reason, since the frequency | count of voltage application by a 2nd execution part reduces compared with the structure where the voltage application by a 2nd execution part is performed whenever the voltage application by a 1st execution part is performed, a 2nd execution part It is possible to suppress the deterioration of the electrode due to the voltage application. On the other hand, when the discharge state due to the voltage application of the third execution unit indicates that the deterioration of the electrode is progressing, the ionization of the gas mixture is promoted by the voltage application of the second execution unit to generate plasma. An environment in which discharge due to voltage application at the first execution unit is likely to occur can be created in the combustion chamber. Therefore, the ignitability to the mixed gas can be enhanced while suppressing the deterioration of the electrode.

  In addition, the code | symbol in the bracket | parenthesis described in a claim and this clause only shows the correspondence with the specific means as described in embodiment mentioned later, and does not limit a technical range.

The block diagram for demonstrating the ignition device in 1st Embodiment. The figure which shows the structure of the gap periphery of a spark plug. The chart for demonstrating the electric current which flows into an ignition device. The timing chart for demonstrating the drive of an ignition device about the case where an electrode is in a deterioration progress state. The graph for demonstrating the applied voltage at the time of arc discharge generation | occurrence | production. The timing chart for demonstrating the drive of an ignition device about the case where an electrode is in a normal state. The flowchart which shows the procedure of an ignition control process. The flowchart which shows the procedure of a plasma determination process. The figure which shows the relationship between the driving load of an engine, and a request voltage.

  Hereinafter, a plurality of embodiments of the present disclosure will be described based on the drawings. In addition, the overlapping description may be abbreviate | omitted by attaching | subjecting the same code | symbol to the corresponding component in each embodiment. When only a part of the configuration is described in each embodiment, the configuration of the other examples described above can be applied to other portions of the configuration. Moreover, not only the combination of the configurations explicitly described in the description of each embodiment, but also the configuration of a plurality of embodiments can be partially combined even if they are not explicitly described, as long as there is no problem in the combination. And the combination where the structure described in several embodiment and the modification is not specified shall also be disclosed by the following description.

(First embodiment)
As shown in FIG. 1, the ignition device 100 includes a spark plug 10 and an ignition circuit 20. The spark plug 10 is provided in a combustion chamber 200 of an internal combustion engine (engine). A spark discharge (glow discharge) is generated in the spark plug 10 by the ignition circuit 20. Thereby, the mixed gas in the combustion chamber 200 is ignited.

<Engine behavior>
Hereinafter, before describing the ignition device 100, the behavior of the engine will be described. This engine is a 4-cycle engine. An engine in a combustion drive state sequentially performs the following intake stroke, compression stroke, combustion expansion stroke, and exhaust stroke. These four strokes are performed in one combustion cycle, which is one cycle of the engine combustion cycle.

  In the intake stroke, the piston of the engine descends in the cylinder in conjunction with the rotation of the crankshaft. This increases the capacity of the combustion chamber 200 defined by the cylinder and the piston. At this time, the combustion chamber 200 communicates with the intake port by the intake valve, and the gas (mainly air) in the intake port is sucked into the combustion chamber 200. Further, mist fuel is injected into the combustion chamber 200 from the injector. As a result, a mixed gas in which the gas in the intake port and the fuel are mixed flows into the combustion chamber 200.

  In the compression stroke, the piston passes through the bottom dead center and moves up in the cylinder. Thereby, the capacity of the combustion chamber 200 is reduced. At this time, the communication between the combustion chamber 200 and the intake port is blocked by the intake valve. Of course, the communication between the combustion chamber 200 and the exhaust port is blocked by the exhaust valve. Thereby, the mixed gas in the combustion chamber 200 is compressed.

  In the combustion expansion stroke, glow discharge is generated in the spark plug 10 when the piston is moving up toward the top dead center or when the piston is moving down beyond the top dead center. As a result, the gas mixture is ignited and burns and explodes. The mixed gas in the combustion chamber 200 expands, and thereby the piston moves down. The kinetic energy of the piston due to this explosion is converted into the rotational energy of the crankshaft. The rotational energy of the crankshaft is output as output of the engine to a drive wheel or the like via a power transmission device.

  In the exhaust stroke, when the piston starts to rise past the bottom dead center, the combustion chamber 200 communicates with the exhaust port by driving the exhaust valve. Thereby, the exhaust in the combustion chamber 200 is discharged.

  After the exhaust stroke, when the piston starts to move past the top dead center, the intake stroke is performed again. As described above, the engine in the combustion drive state sequentially performs the four strokes of the intake stroke, the compression stroke, the combustion expansion stroke, and the exhaust stroke.

<Configuration of ignition device>
Next, the ignition device 100 will be described. As described above, the ignition device 100 includes the ignition plug 10 and the ignition circuit 20. The spark plug 10 has a center electrode 11 and a ground electrode 12. As shown in FIG. 1, the center electrode 11 is connected to the ignition circuit 20. The ground electrode 12 is connected to the ground. The spark plug 10 corresponds to an ignition unit, and the ignition circuit 20 corresponds to a voltage application unit.

  As shown in FIG. 2, the center electrode 11 and the ground electrode 12 are spaced apart from each other in the combustion chamber 200. A part of the center electrode 11 protrudes toward the ground electrode 12 side. In contrast, the portion of the ground electrode 12 facing the center electrode 11 has a flat plate shape. The flat plate portion of the ground electrode 12 and the protruding portion of the center electrode 11 are spaced apart from each other. In the following, the gap between the center electrode 11 and the ground electrode 12 is indicated as a gap G. The spark plug 10 also has an insulator 13 that supports the center electrode 11 and a housing 14 that supports the insulator 13 and the ground electrode 12. A plurality of grooves for promoting the occurrence of glow discharge may be formed on the surface of the flat plate portion of the ground electrode 12 on the center electrode 11 side.

  As shown in FIG. 1, the ignition circuit 20 includes a first path L1 that connects the positive electrode of the battery 40 mounted on the vehicle and the ground, and a second path L2 that connects the first path L1 and the center electrode 11. Have. The ignition circuit 20 includes an ignition coil 21, an igniter 22, and a diode 23 provided in the first path L1 and the second path L2. Furthermore, the ignition circuit 20 has an engine ECU 24. The igniter 22 corresponds to a switch element.

  The ignition coil 21 has a primary coil 21a and a secondary coil 21b that are magnetically coupled. In FIGS. 1 and 3, the magnetic coupling is indicated by hatching. The igniter 22 is an N channel type MOSFET. The igniter 22 is controlled to open and close by the engine ECU 24.

  The engine ECU 24 is an ignition control device that controls the operation of the ignition device 100. The engine ECU 24 includes a computer that includes a processor, a storage unit, an input / output interface, and the like. The storage unit includes a RAM, a memory, and the like. The engine ECU 24 is electrically connected to various sensors mounted on the vehicle and various ECUs. These various sensors are collectively shown as an in-vehicle sensor 300 in FIG. Various ECUs are collectively shown as an in-vehicle ECU 400.

  Various sensor signals detected by the in-vehicle sensor 300 are input to the engine ECU 24. The engine ECU 24 transmits and receives signals to and from the in-vehicle ECU 400 through the in-vehicle network. The engine ECU 24 determines generation and output of a control signal to be output to the igniter 22 based on various sensor signals input from the in-vehicle sensor 300 and various vehicle information input from the in-vehicle ECU 400.

<Circuit configuration of ignition device>
As shown in FIG. 1, in the first path L1, the primary coil 21a and the igniter 22 are connected in series in order from the positive electrode of the battery 40 to the ground. One end of the primary coil 21 a is connected to the positive electrode of the battery 40. The other end of the primary coil 21 a is connected to the drain electrode of the igniter 22. The source electrode of the igniter 22 is connected to the ground. The gate electrode of the igniter 22 is connected to the engine ECU 24. The closed state and open state of the igniter 22 are controlled by a control signal output from the engine ECU 24 to the igniter 22. The ground corresponds to the reference potential.

  The second path L2 connects the center electrode 11 and the midpoint between the battery 40 and the primary coil 21a in the first path L1. In the second path L2, the diode 23 and the secondary coil 21b are connected in series sequentially from the connection point with the first path L1 toward the center electrode 11. The cathode electrode of the diode 23 is connected to the connection point between the first path L1 and the second path L2. The anode electrode of the diode 23 is connected to one end of the secondary coil 21b. The other end of the secondary coil 21 b is connected to the center electrode 11.

<Behavior of ignition device>
Next, the behavior of the ignition device 100 will be described with reference to FIG. In FIG. 3, the description of the reference numerals is omitted in order to avoid complicated description.

  An AC voltage or a DC voltage is applied to the center electrode 11 of the ignition device 100 by opening / closing control of the igniter 22 by a control signal output from the engine ECU 24. Hereinafter, a control signal for applying an AC voltage to the center electrode 11 is referred to as a plasma signal. A control signal for applying a DC voltage to the center electrode 11 is referred to as an ignition signal.

  The plasma signal is a pulse signal including a plurality of pulses generated by switching the voltage level between a high level and a low level at a predetermined period. The frequency of this plasma signal is an integral multiple of the resonance frequency of the secondary coil 21b. In the present embodiment, the frequency of the plasma signal is 1 times the resonance frequency of the secondary coil 21b. This frequency is, for example, about 15 kHz.

  When the plasma signal is at a high level, the igniter 22 is closed. Therefore, as shown in the column (a) of FIG. 3, a current flows from the battery 40 to the ground via the primary coil 21a and the igniter 22 in the first path L1. When the plasma signal is switched from the high level to the low level, the igniter 22 changes from the closed state to the open state. As a result, no current flows through the primary coil 21a as shown in the column (b) of FIG. However, the switching of the igniter 22 from the closed state to the open state is repeatedly performed at 15 kHz, for example, as described above. Therefore, the amount of current flowing through the primary coil 21a changes continuously in time. Therefore, the strength of the magnetic field generated from the primary coil 21a also changes continuously with time. Thus, the magnetic field whose intensity changes continuously in time passes through the secondary coil 21b. As a result, an induced electromotive force is constantly generated in the secondary coil 21b.

  The direction in which the induced electromotive force generated in the secondary coil 21b changes continuously in time according to the increase and decrease of the current flowing through the primary coil 21a. That is, the induced electromotive force changes in an alternating manner. Therefore, the voltage (applied voltage) applied to the center electrode 11 connected to the other end of the secondary coil 21b also changes in an alternating manner.

  When this applied voltage is lower than the power supply voltage of the battery 40, a reverse bias is applied to the diode 23. As shown in the column (a) of FIG. 3, even in this case, a small amount of current flows through the diode 23. The amount of current flowing through the diode 23 is about several μA.

  On the other hand, when the applied voltage is higher than the power supply voltage of the battery 40, a forward bias is applied to the diode 23. As shown in the column (b) of FIG. 3, a current directed to the battery 40 flows through the diode 23.

  As described above, when the igniter 22 is controlled to open and close with a predetermined period by the plasma signal, an AC voltage is applied to the center electrode 11. As a result, at least one of corona discharge and glow discharge is generated at the center electrode 11.

  The corona discharge and the glow discharge are continuous discharges that occur when a non-uniform electric field is generated around the center electrode 11. By the generation of at least one of corona discharge and glow discharge, a plurality of streamers are formed between the center electrode 11 and the ground electrode 12 as paths through which charged particles pass. Thereby, the mixed gas located in the vicinity of the center electrode 11 is ionized. In other words, the mixed gas located in the vicinity of the center electrode 11 is ionized to generate plasma, and a plasma atmosphere is generated. As a result, the number of free electrons contained in the mixed gas increases.

  The ignition signal is a pulse signal including a single pulse generated by switching to a low level after the voltage level is maintained at a high level for a predetermined time. The predetermined time kept at the high level is determined based on the above-described ionization promotion condition and various information described later. A map for these plasma signals and various information is stored in the storage unit of the engine ECU 24. The engine ECU 24 determines a predetermined time based on the plasma signal, various information, and a map stored in the storage unit. Of course, such a map is obtained by conducting various experiments in advance. Various maps will appear in the following, but these are also obtained in advance by conducting various experiments in the same manner. Various maps are stored in the storage unit of the engine ECU 24.

  When the ignition signal is at a high level, the igniter 22 is closed. Therefore, as shown in the column (c) of FIG. 3, current flows from the battery 40 to the ground via the primary coil 21a and the igniter 22 in the first path L1. At this time, a reverse bias corresponding to the power supply voltage of the battery 40 is applied to the diode 23. Therefore, almost no current flows through the diode 23. No current flows through the secondary coil 21b of the second path L2. However, the magnetic field generated from the primary coil 21a continues to pass through the secondary coil 21b. Thereby, magnetic energy continues to be accumulated in the secondary coil 21b.

  When the ignition signal changes from the high level to the low level, energization through the primary coil 21a in the first path L1 is stopped. For this reason, the magnetic field that has passed through the secondary coil 21b rapidly decreases, and an induced electromotive force is generated in the secondary coil 21b. The induced electromotive force is positive on the diode side and negative on the center electrode 11 side. The voltage applied to the center electrode 11 becomes lower than the ground potential, and the ground electrode 12 becomes higher than the center electrode 11. Dielectric breakdown occurs between the center electrode 11 and the ground electrode 12, and arc discharge occurs from the ground electrode 12 toward the center electrode 11. As a result, as shown in the column (d) of FIG. 3, a current flows from the center electrode 11 to the battery 40 through the secondary coil 21b and the diode 23 in the second path L2. This arc discharge is likely to occur as the number of free electrons contained in the mixed gas between the center electrode 11 and the ground electrode 12 increases. The voltage applied to the center electrode 11 by this ignition signal corresponds to the voltage application to the electrode by the first execution unit.

  As described above, at least one of corona discharge and glow discharge is generated at the center electrode 11 by the generation of the AC voltage by the plasma signal. As a result, the gas mixture is ionized to generate plasma, and the number of free electrons contained in the gas mixture increases.

  Therefore, before the arc discharge is generated by the ignition signal, plasma is generated in advance by generating corona discharge or glow discharge at the center electrode 11 to increase the number of free electrons contained in the mixed gas. Thereby, it can be promoted by plasma that arc discharge occurs between the center electrode 11 and the ground electrode 12.

  As described above, the engine sequentially performs the four strokes of the intake stroke, the compression stroke, the combustion expansion stroke, and the exhaust stroke. These various strokes are linked to the rotation angle of the crankshaft. The in-vehicle sensor 300 includes a rotation sensor that detects the rotation angle of the crankshaft. Therefore, the rotation angle of the crankshaft is input from the in-vehicle sensor 300 to the engine ECU 24. The engine ECU 24 determines which stroke the engine is performing based on the rotation angle of the crankshaft. And engine ECU24 determines the output timing of a plasma signal and an ignition signal.

  Specifically, the engine ECU 24 outputs a plasma signal to the igniter 22 after the intake stroke. Thereafter, the engine ECU 24 sets the control signal to a high level and starts to output an ignition signal at a predetermined time before the start of the combustion expansion stroke in the compression stroke. As a result, the voltage level of the ignition signal is switched from the high level to the low level after a lapse of a predetermined time from the start of the ignition signal output. At this time, glow discharge occurs, and the combustion expansion stroke starts.

  In the following, the control signal is referred to as a control signal CS in order to simplify the notation. The plasma signal is denoted as plasma signal IPS. The ignition signal is indicated as an ignition signal IS. A voltage applied to the center electrode 11 is indicated as an applied voltage V2. The current flowing through the secondary coil 21b is denoted as current I2. The predetermined time is indicated as a predetermined time Δt. The same applies to the drawings.

  As shown in FIG. 4, the engine ECU 24 of the present embodiment outputs a plasma signal IPS to the igniter 22 during a period from the intake stroke start timing t1 to the end timing t2. As a result, the applied voltage V2 changes like an AC voltage. The amplitude of the applied voltage V2 is about 2.0 to 4.0 kV. At this time, the current I2 also changes like an alternating current. However, the current I2 at this time has an order of magnitude smaller than the discharge current when the glow discharge occurs. Therefore, in FIG. 4, the current I2 is shown so as not to change.

  As described above, in the intake stroke, the capacity of the combustion chamber 200 increases as the piston descends, and the gas in the intake port is sucked into the combustion chamber 200. Therefore, in this intake stroke, the gas is not easily discharged out of the combustion chamber 200, and the mixed gas flows in the combustion chamber 200. Therefore, the mixed gas flows through the gap between the center electrode 11 and the ground electrode 12. At this time, at least one of corona discharge and glow discharge is generated in the center electrode 11 by the output of the plasma signal IPS. Therefore, the mixed gas flowing through the gap is sequentially ionized. As a result, the gas mixture in the combustion chamber 200 is ionized on average, and the number of free electrons increases.

  As described above, in the compression stroke, communication between the intake port, the exhaust port, and the combustion chamber is blocked. Therefore, it is difficult for the gas mixture having an increased number of free electrons due to corona discharge or glow discharge to be discharged out of the combustion chamber 200.

  The engine ECU 24 estimates the timing t3 when the piston rises and reaches the top dead center in the compression stroke based on the rotation speed of the crankshaft. Then, the engine ECU 24 calculates a timing that is faster than the timing t3 by a predetermined time Δt. The predetermined time Δt is calculated based on the degree of ionization promotion (the number of free electrons) and various information as described above.

  The engine ECU 24 sets the control signal CS to high level and starts outputting the ignition signal IS at a timing t4 that is earlier than the timing t3 by a predetermined time Δt. As a result, a current flows through the primary coil 21a, and magnetic energy is accumulated in the secondary coil 21b.

  When a predetermined time Δt elapses from timing t4 and reaches timing t3, the engine ECU 24 changes the ignition signal IS from a high level to a low level. As a result, as shown in FIG. 4, the applied voltage V2 suddenly becomes lower than the ground potential. When the voltage level of the applied voltage V2 becomes so low that dielectric breakdown occurs between the center electrode 11 and the ground electrode 12, glow discharge occurs between the center electrode 11 and the ground electrode 12, and a discharge current flows. . When the discharge current flows in this way, the energy accumulated in the secondary coil 21b is released. The discharge current at the peak is about several tens of mA. After timing t3, the applied voltage V2 and the current I2 decrease.

  In FIG. 5, the applied voltage V2 at the time of occurrence of glow discharge when the number of free electrons is increased by corona discharge or glow discharge is shown by a solid line. The applied voltage V2 when glow discharge occurs when the number of free electrons is not increased is indicated by a broken line. The required voltage shown in FIG. 5 indicates the voltage level of the applied voltage V2 required for arc discharge to occur. As clearly shown in FIG. 5, when the number of free electrons is increased, the required voltage is smaller than when the number of free electrons is not increased.

  In the spark plug 10, there is a concern that the spark G is less likely to occur between the center electrode 11 and the ground electrode 12 due to the gap G being enlarged. Here, as measures against environmental conservation and fuel depletion problems, for example, for gasoline engines, there is a method of reducing fuel consumption by increasing the compression ratio of a naturally aspirated engine or by using a supercharged downsizing engine. In a high-compression engine or a supercharged downsizing engine, the temperature and pressure of the combustion chamber 200 tend to increase, so that the wear and deterioration of the center electrode 11 and the ground electrode 12 of the spark plug 10 tend to progress as the vehicle travel distance increases. The gap G is easy to expand.

  When the use period of the spark plug 10 increases, such as an increase in the vehicle travel distance, and the deterioration of the spark plug 10 progresses, such as the gap G increases, the required voltage for generating spark discharge in the spark plug 10 increases. The required voltage is a discharge voltage required to cause dielectric breakdown in the gap G of the spark plug 10, and the required voltage gradually increases as the gap G increases. For this reason, if the gap G is expanded to such an extent that spark discharge is less likely to occur, the required voltage tends to be excessively high, and the electrodes 11 and 12 are likely to deteriorate. Therefore, it is necessary to take measures against the required voltage increase due to the aging of the spark plug 10 and the electrode consumption.

  In the present embodiment, as described above, when both the voltage application for generating plasma and the voltage application for generating arc discharge are performed on the electrodes 11 and 12, these electrodes 11 and 12 are applied. Concern is likely to deteriorate. Therefore, in this embodiment, it is determined whether or not to apply a voltage for generating plasma, and this voltage application is not performed as much as possible, thereby making it difficult for the electrodes 11 and 12 to progress. Hereinafter, voltage application for generating plasma is referred to as plasma voltage application, and voltage application for generating arc discharge is referred to as ignition voltage application.

  Specifically, the engine ECU 24 applies a determination voltage that is neither a plasma voltage application nor an ignition voltage application to the electrodes 11 and 12 and determines whether or not a discharge is properly generated at the electrodes 11 and 12. When the discharge is appropriately generated by applying the determination voltage, the plasma voltage is not applied on the assumption that the electrodes 11 and 12 are not deteriorated or are in a proper state in which the progress of the deterioration remains slightly. On the other hand, when the discharge is not properly generated due to the application of the determination voltage, the plasma voltage is applied on the assumption that the electrodes 11 and 12 are in a deterioration progress state in which the deterioration is difficult to occur. In addition, when discharge does not generate | occur | produce appropriately by ignition voltage application, it will misfire.

  As shown in FIG. 4, the voltage applied to the center electrode 11 by applying the determination voltage is an AC voltage, and this AC voltage has the same value and cycle as the AC voltage applied to the center electrode 11 by applying the plasma voltage. have. On the other hand, the determination voltage application duration Tb is shorter than the plasma voltage application duration Ta.

  When the control signal output by the engine ECU 24 to apply the determination voltage is referred to as a determination signal EPS, the determination signal EPS is generated by switching the voltage level between a high level and a low level in a predetermined cycle. It is a pulse signal containing the pulse of. The determination signal EPS has the same frequency as the plasma signal IPS.

  The engine ECU 24 outputs a determination signal EPS to the igniter 22 in the exhaust stroke. As a result, the applied voltage V2 changes like an AC voltage. The engine ECU 24 outputs the determination signal EPS so that the change in the applied voltage V2 due to the determination signal EPS is included between the exhaust stroke start timing t0 and the intake stroke start timing t1. Here, in the exhaust stroke, even if a discharge occurs between the electrodes 11 and 12 due to the exhaust of the mixed gas from the combustion chamber 200, it is difficult for the mixed gas to ignite.

  When the electrodes 11 and 12 are in the deterioration progress state, if no discharge occurs in the gap G even if voltage is applied by the determination signal EPS, the current I2 does not flow or even if it flows, Only. In this case, the engine ECU 24 outputs the plasma signal IPS in the intake stroke to generate plasma in the combustion chamber 200, assuming that the discharge due to the ignition signal IS is unlikely to occur, thereby generating the discharge due to the ignition signal IS in the compression stroke. Promote.

  On the other hand, as shown in FIG. 6, when discharge in the gap G is generated by the determination signal EPS due to the electrodes 11 and 12 being in a normal state, the current I2 is an appropriate value corresponding to the applied voltage V2. Value. In this case, the engine ECU 24 does not output the plasma signal IPS in the intake stroke because it is easy for discharge due to the ignition signal IS to occur. That is, plasma is not generated in the combustion chamber 200.

  When the electrodes 11 and 12 are in a normal state, the discharge generated by the determination signal EPS may be any of arc discharge, corona discharge, and glow discharge. Regardless of which discharge occurs, the current I2 flows between the electrodes 11 and 12. Here, in the combustion chamber 200, when a voltage is applied to the center electrode 11, an electric field is generated, and initial electrons existing in the space move. In this case, as the electrons move, the electrons emitted by ionizing the gas molecules by the α action are further accelerated by the electric field, and the ionization by the α action repeatedly occurs, leading to the avalanche and the discharge. In addition, when the electrodes 11 and 12 are in a deterioration progressing state, plasma is generated with the application of voltage to the center electrode 11, but no avalanche occurs and no discharge occurs.

<Ignition control processing>
The engine ECU 24 performs an ignition control process for controlling the operation of the ignition device 100. Here, the ignition control process will be described with reference to the flowcharts of FIGS.

  In FIG. 7, in step S101, operation information relating to the operating state of the engine is acquired. Here, the engine rotation speed and the engine load information are read from the in-vehicle sensor 300 and the in-vehicle ECU 400 as the operation information.

  In step S102, a plasma determination process is performed to determine whether or not to generate plasma at a timing prior to generating arc discharge in the combustion chamber 200. The plasma determination process will be described with reference to the flowchart of FIG. In FIG. 8, in step S201, it is determined whether or not a deterioration flag indicating that the electrodes 11 and 12 are in a deterioration progress state is set. The deterioration flag is a flag that is set in a storage unit or the like of the engine ECU 24.

  When the deterioration flag is not set, in steps S202 and S203, it is determined whether or not the deterioration of the electrodes 11 and 12 is to be determined based on the operating state of the engine. In step S202, it is determined whether the engine operating state is in a high load state. The engine operating state includes at least a low load state and an intermediate load state in addition to the high load state, and the high load state is a state in which the load is higher than both the low load state and the intermediate load state. Examples of the case where the engine is in a high load state include a case where the vehicle is traveling on an uphill slope and a case where the intake air amount into the engine has increased abruptly.

  As shown in FIG. 9, the required voltage by the ignition signal IS increases as the engine operating load increases. This is due to the fact that the higher the engine operating load, the higher the in-cylinder pressure at the time of ignition, the higher the flow rate of the mixed gas in the combustion chamber 200, and the easier the electrons are blown from the gap G. This is because the discharge at the electrodes 11 and 12 is less likely to occur. In this case, if the in-cylinder pressure at the time of ignition is high, the voltage required for generating discharge at the electrodes 11 and 12 becomes high. In other words, the lower the engine operating load, the easier the discharge at the electrodes 11 and 12 occurs. Therefore, even if the electrodes 11 and 12 are in a state of progress of deterioration, the engine operating state is low. In the state, discharge due to the ignition signal IS is likely to occur properly. For this reason, it can be said that the discharge due to the ignition signal IS is less likely to occur when the electrodes 11 and 12 are in the deterioration progressing state when the engine operating state is in a high load state.

  Further, a map indicating the relationship between the in-cylinder pressure at ignition and the required voltage is stored in the storage unit for the engine operating region. Then, by using this map, it is determined whether or not the in-cylinder pressure has increased to the extent that the engine operating region can be said to be a high load region by determining whether or not the required voltage has become larger than a predetermined value such as 40 kV. To do. That is, when the required voltage becomes larger than a predetermined value, it is determined that the engine operating region is in the high load region. In addition, for this map, the in-cylinder pressure is acquired from the engine speed and the engine load information, and the larger the in-cylinder pressure and the required voltage, the higher the engine operating load becomes.

  In step S203, it is determined whether or not the engine is warming up. Here, it is determined whether or not the engine coolant temperature is lower than a predetermined temperature, and whether or not the engine oil temperature is lower than a predetermined temperature. When the cooling water temperature is lower than the predetermined temperature or when the engine oil temperature is lower than the predetermined temperature, it is determined that the engine is performing a warm-up operation. When the engine is warming up, the engine is in the middle of warming up.

  When the engine operating state is a high load state and the engine warm-up operation has been completed, it is determined whether or not the electrodes 11 and 12 are in a deterioration progress state, and the processes of steps S204 to S210 are performed. Do.

  In step S204, the value of the voltage applied to the center electrode 11 is set by the determination signal EPS. Here, the applied voltage by the determination signal EPS is set to a value larger than the applied voltage by the plasma signal IPS. In other words, the applied voltage by the plasma signal IPS is smaller than the applied voltage by the determination signal EPS. Here, when a voltage is applied by the plasma signal IPS, as long as a plasma atmosphere can be generated, it may not be generated even if a discharge occurs. Therefore, the voltage applied by the plasma signal IPS can be minimized. In this case, as the applied voltage by the plasma signal IPS is smaller, the deterioration of the electrodes 11 and 12 due to application of the plasma voltage can be made difficult to proceed. Note that the applied voltage by the determination signal EPS is set to a value smaller than the applied voltage by the ignition signal IS.

  In step S205, a determination voltage application duration Tb based on the determination signal EPS is set. Here, the continuation period Tb is set to a period shorter than the continuation period Ta of the plasma voltage application by the plasma signal IPS. Here, the application of the plasma voltage needs to generate an amount of plasma that can promote discharge in the combustion chamber 200, but the determination voltage application only needs to be able to determine whether or not a discharge has occurred. For this reason, from the viewpoint of making the deterioration of the electrodes 11 and 12 difficult to proceed, it is preferable that the duration Tb of the determination voltage application is as short as possible.

  In addition, the start timing and end timing of application of the determination voltage are set. Here, the determination voltage application start timing is set to a timing delayed by a predetermined time from the engine exhaust stroke start timing t0. Further, the end timing of application of the determination voltage is set to a timing earlier by a predetermined time than the start timing t1 of the intake stroke of the engine. In this case, the robustness can be improved as compared with the configuration in which the determination voltage is applied in the entire period except immediately after the exhaust valve is opened and immediately before the exhaust valve is closed.

  In step S206, it is determined whether an exhaust stroke has been started. If the exhaust stroke has not been started, this determination is repeated to wait in step S206. When the exhaust stroke is started, the process proceeds to step S207. In the present embodiment, when the exhaust stroke is started, the determination signal EPS is output so that the determination voltage application is started after waiting for a predetermined time. In step S207, the determination signal EPS is output to the igniter 22 of the ignition device 100. Thereby, the determination voltage is applied to the electrodes 11 and 12.

  In step S208, it is determined whether or not a discharge has occurred in the electrodes 11 and 12 by applying a determination voltage. Here, it is determined whether or not the current I2 flowing along with the determination voltage application has become larger than a predetermined reference value once for the entire duration Tb of the determination voltage application. Then, it is determined that the discharge has occurred when the current I2 is greater than the reference value, and it is determined that the discharge has not occurred when the current I2 is not greater than the reference value. As shown in FIG. 6, a threshold value or the like is set so as to be sandwiched between upper and lower amplitudes with respect to data indicating a change in the current I2, and discharge occurs when the current I exceeds the threshold. May be determined.

  If no discharge is generated by the determination signal EPS, the process proceeds to step S209, and the deterioration flag is set in the storage unit or the like of the engine ECU 24, assuming that the electrodes 11 and 12 are in the deterioration progress state. On the other hand, when the discharge is generated by the determination signal EPS, the process proceeds to step S210, and the deterioration flag is not set assuming that the electrodes 11 and 12 are in the normal state.

  When the processing of steps S209 and S210 is completed, and the plasma determination processing of step S102 is completed, the process returns to the description of FIG. 7 and proceeds to step S103. In step S103, it is determined whether a deterioration flag is set. When the deterioration flag is set, the processing of steps S104 to S108 is performed assuming that the plasma voltage is applied.

  In step S104, the value of the voltage applied to the center electrode 11 is set by the plasma signal IPS. Here, as described in step S204 above, the voltage applied by the plasma signal IPS is set to a value equal to or lower than the voltage applied by the determination signal EPS. Note that the voltage applied by the plasma signal IPS is set to a value smaller than the voltage applied by the ignition signal IS.

  In step S105, the duration Ta of the plasma voltage application by the plasma signal IPS is set. Here, as described in step S205, the continuation period Ta is set to a period that is the same as or longer than the continuation period Tb of the determination voltage application by the determination signal EPS.

  In step S106, it is determined whether the intake stroke has started. If the intake stroke has not been started, this determination is repeated to wait in step S106. In the present embodiment, the plasma signal IPS is output so that the application of the plasma voltage is started at the timing when the intake stroke is started. In step S107, the plasma signal IPS is output to the igniter 22 of the ignition device 100. Thereby, plasma voltage application is performed on the electrodes 11 and 12.

  In step S108 performed after step S107, an ignition process is performed in a state where a plasma atmosphere is generated in the combustion chamber 200 by the process of step S107. In this ignition process, an ignition signal IS is output in accordance with the ignition timing, and arc discharge is generated at the electrodes 11 and 12.

  If it is determined in step S103 that the deterioration flag is not set, it is determined that the electrodes 11 and 12 are in a normal state, and the process directly proceeds to step S108 without performing steps S104 to S107. In this case, even if the plasma atmosphere is not generated in the combustion chamber 200, arc discharge is generated in the electrodes 11 and 12 by performing the ignition process in step S108 due to the electrodes 11 and 12 being in a normal state. It will occur properly.

  The engine ECU 24 has a function of executing each step of the ignition control process. The function that executes the process of step S108 corresponds to the first execution unit, the function that executes the process of step S107 corresponds to the second execution unit, and the function that executes the process of step S207 corresponds to the third execution unit. . The function of executing the processes of steps S103 and S208 corresponds to the second execution determination unit, and in particular, the function of executing the process of step S208 corresponds to the discharge determination unit. The function of executing the processes of steps S202, S203, and S206 corresponds to the third execution determination unit. In particular, the function of executing the process of step S202 corresponds to the driving determination unit, and the function of executing the process of step S203 is warm. It corresponds to a machine determination unit.

<Effect>
According to the present embodiment described so far, it is determined whether or not to apply plasma voltage based on the discharge state at the electrodes 11 and 12 by applying the determination voltage. In this case, since the number of times the plasma voltage is applied is reduced as compared with the configuration in which the plasma voltage is applied each time the ignition voltage is applied, the electrodes 11 and 12 are further deteriorated by applying the plasma voltage. That can be suppressed. On the other hand, when the discharge state due to the application of the determination voltage indicates that the electrodes 11 and 12 are in the deterioration progress state, by generating a plasma atmosphere in the combustion chamber 200 by applying the plasma voltage, The occurrence of arc discharge due to application of the ignition voltage can be accelerated. Therefore, the ignitability to the mixed gas can be improved while suppressing the deterioration of the electrodes 11 and 12.

  According to this embodiment, the determination voltage is applied according to the operating state of the engine. In this case, since it becomes possible to select the operation state that increases the determination accuracy of the discharge state by applying the determination voltage and apply the determination voltage, the determination accuracy of the deterioration state of the electrodes 11 and 12 can be improved. it can. For this reason, the frequency | count of producing | generating a plasma atmosphere by plasma voltage application can be suppressed to the minimum.

  According to this embodiment, since the determination voltage is applied when the engine operating state is in a high load state, the deterioration state of the electrodes 11 and 12 is determined based on the discharge state of the electrodes 11 and 12 in the high load state. Can be judged. Here, when the operating state of the engine is in a high load state, since the discharge at the electrodes 11 and 12 is less likely to occur than in the case of a low load state, the electrodes 11 and 12 are deteriorated. The degree of progress is likely to appear remarkably in the discharge state, and the accuracy of deterioration determination can be increased.

  Moreover, the frequency at which the engine operating state becomes a high load state is likely to vary depending on the user of the vehicle, and depending on the user, the frequency at which the engine is in a high load state may be very low. For this reason, there is a concern that the deterioration of the electrodes 11 and 12 may proceed before the engine operating state becomes a high load state after the deterioration determination of the electrodes 11 and 12 is performed by applying the determination voltage. In response to this concern, since the deterioration state of the electrodes 11 and 12 when the engine operating state is in a high load state is determined, discharge is not properly generated in the electrodes 11 and 12 in the high load state. That can be suppressed.

  Furthermore, it is assumed that the frequency at which the engine is in a high load state is lower than the frequency at which the engine is in a low load state. For this reason, the frequency | count of determination voltage application can be reduced by setting the driving | running state with low frequency to the execution conditions of deterioration determination. Thereby, it can suppress that degradation of the electrodes 11 and 12 advances by determination voltage application.

  According to the present embodiment, the determination voltage is applied when the warm-up operation of the engine is finished. Here, when the warm-up operation of the engine is performed, it is assumed that the state of occurrence of discharge at the electrodes 11 and 12 varies due to the fact that the flow rate of the mixed gas in the combustion chamber 200 tends to vary. The For this reason, even if the deterioration determination of the electrodes 11 and 12 is performed during the warm-up operation of the engine, there is a concern that the determination accuracy may be lowered due to variations in the discharge occurrence state. On the other hand, since the discharge state of the electrodes 11 and 12 is easily stabilized by applying the determination voltage after the engine warm-up operation is completed, the accuracy of deterioration determination can be increased.

  According to the present embodiment, since the determination voltage application is performed in the exhaust stroke of the engine, it is possible to avoid that the mixed gas is ignited by the determination voltage application. Moreover, even if plasma is generated by applying the determination voltage, this plasma is discharged from the combustion chamber 200 together with the exhaust in the exhaust stroke. For this reason, it can be suppressed that the state of the intake air taken into the combustion chamber 200 during the intake stroke is unintentionally changed by the application of the determination voltage, and the ignitability of the mixed gas is reduced. Further, even if the engine is in a high load state, in the exhaust stroke, the in-cylinder pressure becomes relatively low as the exhaust is discharged, so that the electrodes 11 and 12 are likely to be discharged by applying the determination voltage. It has become. For this reason, even if the voltage by the determination voltage application is set to a value as low as possible, the deterioration determination of the electrodes 11 and 12 can be accurately performed.

  According to the present embodiment, since the voltage applied to the electrodes 11 and 12 by the plasma signal IPS is smaller than the voltage applied by the determination signal EPS, the electrodes 11 and 12 are deteriorated by the plasma voltage application by the plasma signal IPS. It is possible to suppress progress. This is because, as the voltage applied to the electrodes 11 and 12 is smaller, the energy with which the ions collide with the electrodes 11 and 12 tends to be smaller, so that the deterioration of the electrodes 11 and 12 is less likely to proceed. .

  According to the present embodiment, since the duration Tb of the determination voltage application is shorter than the duration Ta of the plasma voltage application, it is possible to suppress the deterioration of the electrodes 11 and 12 due to the determination voltage application. This is because, as the duration of voltage application to the electrodes 11 and 12 is shorter, the number of times ions collide with the electrodes 11 and 12 tend to decrease, so that the deterioration of the electrodes 11 and 12 is less likely to proceed. It is.

  According to the present embodiment, when a discharge is generated in the electrodes 11 and 12 due to application of the determination voltage, plasma voltage application is not performed. For this reason, priority can be given to suppressing the progress of deterioration of the electrodes 11 and 12 by applying plasma voltage, rather than generating plasma by applying plasma voltage and increasing the probability of occurrence of discharge by applying ignition voltage. Here, if the state of the electrodes 11 and 12 is so good that the discharge is generated by the application of the determination voltage, it is considered very likely that the discharge of the electrodes 11 and 12 is generated by the application of the ignition voltage. Therefore, it is possible to appropriately generate a discharge by applying an ignition voltage without applying a plasma voltage.

(Second Embodiment)
In the said 1st Embodiment, when discharge did not generate | occur | produce by the determination voltage application, it determined with the electrodes 11 and 12 being in a deterioration progress state. In contrast, in the second embodiment, when the state in which no discharge is generated by applying the determination voltage is repeated a plurality of times, it is determined that the electrodes 11 and 12 are in a deterioration progress state. In the present embodiment, the difference from the first embodiment will be mainly described.

  In the present embodiment, the determination process corresponding to step S208 of the first embodiment is performed, and when no discharge is generated by applying the determination voltage, a deterioration counter is set as a process corresponding to step S209. Then, a determination process by applying a determination voltage is performed for each of a plurality of exhaust strokes thereafter, and the number of times that no discharge has occurred is counted by incrementing a deterioration counter when no discharge has occurred. . When the deterioration counter reaches a predetermined number of times, a deterioration flag is set, and it is determined that the electrodes 11 and 12 are in a deterioration progress state.

  According to the present embodiment, it is determined that the electrodes 11 and 12 are in a deterioration progress state when discharge is not properly generated by applying the determination voltage in a plurality of exhaust strokes. In this case, taking into account that the discharge state at the electrodes 11 and 12 becomes unstable due to the operating state of the engine being in a high load state, the accuracy of the deterioration determination of the electrodes 11 and 12 is increased. Can be increased.

(Other embodiments)
Although a plurality of embodiments according to the present disclosure have been described above, the present disclosure is not construed as being limited to the above embodiments, and can be applied to various embodiments and combinations without departing from the gist of the present disclosure. can do.

  As a first modification, the determination voltage application by the determination signal EPS may be performed at any timing in the exhaust stroke of the engine. For example, the determination voltage application may be started from the start timing t0 of the exhaust stroke or may be ended at the start timing t1 of the intake stroke of the engine.

  As a second modification, the determination voltage application by the determination signal EPS is not performed only in the exhaust stroke of the engine, but may be performed in a stroke different from the exhaust stroke. The determination voltage application may be performed, for example, across the exhaust stroke and the intake stroke, or may be performed only in the intake stroke. Even in this case, the deterioration state of the electrodes 11 and 12 can be determined by acquiring the discharge state at the electrodes 11 and 12 by applying the determination voltage using the current I2 or the like.

  As a third modification, the voltage applied to the electrodes 11 and 12 by the determination signal EPS may not be larger than the voltage applied by the plasma signal IPS. For example, the applied voltage by the determination signal EPS may be the same value as the applied voltage by the plasma signal IPS. The determination voltage application duration Tb may not be shorter than the plasma voltage application duration Ta.

  As a fourth modification, the voltage applied to the electrodes 11 and 12 by the determination signal EPS may not be an AC voltage. For example, the applied voltage based on the determination signal EPS may be a DC voltage similarly to the applied voltage based on the ignition signal IS.

  As a fifth modification, the determination voltage application may be performed when the operating state of the engine is not a high load state. For example, the determination voltage is applied when the engine operating state is in a low load state. The determination voltage application may be performed during the warm-up operation of the engine.

  As a modified example 6, information regarding the total travel distance of the vehicle, information regarding the total number of times of ignition by the ignition signal IS, etc., in addition to the operating state of the engine, are used as determination parameters for determining whether or not the electrodes 11 and 12 are deteriorated. May be used. For example, when the engine operating state is in a high load state, the electrodes 11, 11 and 12 are provided on condition that at least one of the total travel distance is greater than a predetermined value and the total number of ignitions is greater than a predetermined value. In this configuration, 12 deterioration determinations are made.

  As a modified example 7, the electrodes to which the plasma voltage application and the ignition voltage application are performed may not be the common electrodes 11 and 12. For example, it is assumed that the electrode to which the plasma voltage is applied and the electrode to which the ignition voltage is applied are independent from each other. In this case, the determination voltage is applied to the electrode to which the plasma voltage is applied.

  As a modified example 8, as the internal combustion engine to which the configuration of the first embodiment for determining the deterioration state of the electrodes 11 and 12 by applying the determination voltage is applied, a high compression engine, a supercharged downsizing engine, a naturally aspirated engine, or the like is used. Can be mentioned. Further, examples of the injection form include an in-cylinder injection engine, an intake port injection engine, and a dual injection engine. Note that the dual injection engine is an engine having both intake port injection and in-cylinder injection.

  As a modified example 9, the configuration that performs the function as the ignition control device may be various arithmetic devices mounted on the vehicle instead of the engine ECU 24, and a plurality of arithmetic devices function as a control device in cooperation with each other. May be demonstrated. Various programs may be stored in a non-transitional tangible storage medium such as a flash memory or a hard disk provided in each arithmetic device.

  DESCRIPTION OF SYMBOLS 10 ... Spark plug as ignition part, 11 ... Center electrode, 12 ... Ground electrode, 20 ... Ignition circuit as voltage application part, 24 ... Engine ECU as ignition control device, 100 ... Ignition device, 200 ... Combustion chamber, S103 2nd execution determination unit, S107 2nd execution unit, S108 1st execution unit, S202 3rd execution determination unit and operation determination unit, S203 3rd execution determination unit and warm-up determination unit, S206 3rd Execution determination unit, S207... Third execution unit, S208... Second execution determination unit and discharge determination unit, Ta, Tb.

Claims (8)

It has electrodes (11, 12) to which a voltage is applied, and discharge can be generated in the combustion chamber (200) of the internal combustion engine by applying a voltage to the electrodes, and the gas mixture in the combustion chamber is generated by the discharge. An ignition part (10) for igniting,
A voltage application unit (20) for applying a voltage to the electrode;
An ignition control device (24) for controlling the operation of the ignition device (100) comprising:
A first execution unit (S108) that causes the voltage application unit to execute voltage application to the electrode in order to generate discharge in the ignition unit;
When the voltage application by the first execution unit is executed, the plasma is generated in the combustion chamber by applying a voltage to the electrode and ionizing the mixed gas so that the plasma exists in the combustion chamber. A second execution unit (S107) that causes the voltage application unit to execute
A third execution unit (S207) for causing the voltage application unit to execute voltage application to the electrodes in order to acquire a discharge state by the ignition unit;
A second execution determination unit (S103, S208) that determines whether or not to execute voltage application by the second execution unit based on a discharge state by the ignition unit when voltage application by the third execution unit is executed. )When,
Ignition control device.   A third execution determination unit (S202, S203, S206) that determines whether or not to cause the third execution unit to execute voltage application to the electrode based on an operating state of the internal combustion engine. Item 2. The ignition control device according to Item 1. The third execution determination unit
An operation determination unit (S202) for determining whether or not the operation state of the internal combustion engine is in a high load state in which a load is larger than a predetermined low load state;
The driving determination unit
The ignition control device according to claim 2, wherein when the operating state of the internal combustion engine is in the high load state, it is determined that the third execution unit executes voltage application to the electrodes. The third execution determination unit
A warm-up determination unit (S203) for determining whether or not the warm-up operation of the internal combustion engine has ended,
The warm-up determination unit
4. The ignition control device according to claim 2, wherein when the warm-up operation of the internal combustion engine is finished, it is determined that the third execution unit executes voltage application to the electrodes. 5.   5. The ignition control device according to claim 1, wherein the third execution unit executes voltage application to the electrode in an exhaust stroke of the internal combustion engine.   The ignition control device according to any one of claims 1 to 5, wherein a voltage applied to the electrode by the second execution unit is smaller than a voltage applied to the electrode by the third execution unit.   The period (Tb) in which a voltage is applied to the electrode by the third execution unit is shorter than a period (Ta) in which a voltage is applied to the electrode by the second execution unit. The ignition control device according to any one of the above. The second execution determination unit
A discharge determination unit (S208) for determining whether or not a discharge by the ignition unit has occurred when voltage application by the third execution unit is performed;
The said 2nd execution part performs the voltage application to the said electrode, when the said discharge determination part judges that the discharge by the voltage application of the said 3rd execution part has not generate | occur | produced. The ignition control device according to any one of the above.

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