JP6330440B2 - Ignition control device - Google Patents

Description

  The present invention constitutes an ignition device for igniting an air-fuel mixture in a combustion chamber of an internal combustion engine. A high voltage is generated in a secondary winding by energizing and shutting down a primary winding of an ignition coil, and applied to an ignition plug for discharge. The present invention relates to an ignition control device to be generated.

2. Description of the Related Art In a vehicle using an internal combustion engine as a driving force source, a technique for improving fuel consumption is known by stopping fuel injection by a fuel injection device of an internal combustion engine during vehicle deceleration.
On the other hand, when fuel is injected into the intake passage, if the fuel cut control as described above is performed, the manifold wet, which is liquid fuel adhering to the inner wall of the intake passage, decreases during the fuel cut state. As a result, there is a problem that misfiring occurs when the air-fuel ratio at the time of returning from the fuel cut state is shifted to the side where the air-fuel ratio becomes larger than the target air-fuel ratio. With respect to this problem, Patent Document 1 performs a correction to increase the fuel injection amount to compensate for the manifold wet amount when returning from the fuel cut state.

JP-A-5-39740

However, when the fuel injection amount is corrected as described in Patent Document 1, it is necessary to increase the fuel injection amount during the period until the manifold wet compensation is completed. There was a problem that faded.
The present invention has been made in view of the above-described points, and an object thereof is to provide an ignition device capable of enhancing the fuel efficiency improvement effect by the fuel cut control.

  The ignition control device according to the present invention includes an ignition switch and an energy input unit. The ignition switch generates a high voltage in the secondary winding of the ignition coil by cutting off a current path between the power source and the primary winding of the ignition coil. The energy input unit is connected to the primary winding or the spark plug, and can input electric energy that allows the discharge to continue into the spark plug.

In particular, the present invention is characterized by further comprising a fuel cut return determination means and an energy control means. The fuel cut return determination means determines a return from the fuel cut state when the fuel injection device of the internal combustion engine stops the fuel injection as the fuel cut state. The energy control means, when the ignition timing interval of the spark plug is defined as an ignition cycle, when it is determined that the fuel cut state has been restored, the energy control means supplies electric energy to the energy input unit until the predetermined number of executions of the ignition cycle elapses from the determination. Command to turn on. The energy control means sets the number of executions based on both or one of the coolant temperature of the internal combustion engine and the duration of the fuel cut state.

  The larger the “electric energy input by the energy input unit in one ignition cycle”, the higher the ignition performance of the air-fuel mixture. For example, “electric energy input by the energy input unit at one ignition cycle” is used to continue the discharge generated by the spark plug by shutting off the ignition switch at the ignition timing.

  Therefore, when the energy input unit returns electric energy when returning from the fuel cut state, the mixture can be reliably ignited even when the manifold wet is less than usual and the mixture becomes thin. Thereby, the correction amount of the fuel injection amount when returning from the fuel cut state can be reduced, or the correction itself can be eliminated. Therefore, according to the present invention, the fuel efficiency improvement effect by the fuel cut control can be enhanced.

It is a figure explaining the schematic structure of the engine system provided with the ignition control device by a 1st embodiment of the present invention. It is a figure explaining the structure of the ignition device of FIG. It is a flowchart explaining the control action of the electronic control unit of FIG. It is a time chart explaining the action | operation of the ignition control apparatus of FIG. It is a map used with the electronic control unit of the ignition control apparatus by 2nd Embodiment of this invention, and is a figure which shows the relationship between the water temperature of an engine, and the frequency | count of continuous discharge after a fuel cut return. It is a time chart explaining the fuel cut continuation time which is the parameter which the electronic control unit uses in the ignition control apparatus by 3rd Embodiment of this invention which is the time when the fuel cut state was continued. It is a map used with the electronic control unit of the ignition control apparatus by 3rd Embodiment of this invention, and is a figure which shows the relationship between fuel cut continuation time and the frequency | count of implementation of the electrical energy input after fuel cut return. It is a figure which shows the relationship between the discharge energy which is the electrical energy which the energy injection | throwing-in part inputs with 1 ignition period controlled by the electronic control unit of the ignition control apparatus by 4th Embodiment of this invention, and the water temperature of an engine. It is a map used with the electronic control unit of the ignition control apparatus by 4th, 6th embodiment of this invention, and is a figure which shows the relationship between the engine water temperature and the continuous period which is a period which continues discharge by energy input. is there. It is a map used with the electronic control unit of the ignition control apparatus by 5th, 6th embodiment of this invention, and is a figure which shows the relationship between engine water temperature and a target secondary current. It is a figure which shows the relationship between the discharge energy controlled by the electronic control unit of the ignition control apparatus by 7th Embodiment of this invention, and fuel cut continuation time. It is a map used with the electronic control unit of the ignition control apparatus by 7th Embodiment of this invention, and is a figure which shows the relationship between fuel cut duration and duration. It is a figure which shows the relationship between the discharge energy controlled by the electronic control unit of the ignition control apparatus by 8th Embodiment of this invention, and ignition cycle progress. It is a map used with the electronic control unit of the ignition control apparatus by 9th Embodiment of this invention, and is a figure which shows the relationship between fuel correction amount and discharge energy.

Hereinafter, a plurality of embodiments of the present invention will be described with reference to the drawings. In the embodiments, substantially the same components are denoted by the same reference numerals and description thereof is omitted.
In the following description, the magnitude of the current is expressed on the basis of the magnitude of the absolute value, the increase in current means the case where the absolute value of the current becomes large, and the decrease in the current means the case where the absolute value becomes small.

<First Embodiment>
The ignition control apparatus according to the first embodiment of the present invention is provided in the engine system shown in FIG.
[Engine system configuration]
First, a schematic configuration of the engine system 10 will be described with reference to FIG.
As shown in FIG. 1, the engine system 10 includes an engine 13 that is a spark ignition type internal combustion engine. The engine 13 burns an air-fuel mixture of air supplied from the intake manifold 15 through the throttle valve 14 and fuel injected from the injector 16 in the combustion chamber 17, and reciprocates the piston 18 by the explosive force at the time of combustion. . The reciprocating motion of the piston 18 is converted into a rotational motion by the crankshaft 19 and output. The combustion gas is released into the atmosphere through the exhaust manifold 20 and the like.

  An intake valve 22 is provided at the inlet of the combustion chamber 17, that is, the intake port of the cylinder head 21, and an exhaust valve 23 is provided at the outlet of the combustion chamber 17, that is, the exhaust port of the cylinder head 21. The intake valve 22 and the exhaust valve 23 are opened and closed by a valve drive mechanism 24. The valve timing of the intake valve 22 is adjusted by the variable valve mechanism 25.

  Ignition of the air-fuel mixture in the combustion chamber 17 is performed by the ignition device 30. The ignition device 30 includes an ignition plug 31, an ignition coil 32, an ignition circuit unit 33, and an electronic control unit 34. The ignition circuit unit 33 is operated based on a command from the electronic control unit 34, and the ignition plug 32 is switched from the ignition coil 32. By applying a high voltage to 31, a spark discharge is generated in the combustion chamber 17. The ignition device 30 will be described in detail later.

  The electronic control unit 34 has a microcomputer including a CPU, ROM, RAM, input / output ports, and the like, and includes a crank position sensor 35, a cam position sensor 36, a water temperature sensor 37, a throttle opening sensor 38, and an intake pressure sensor. It is electrically connected to various sensors such as 39. The electronic control unit 34 controls the operation state of the engine 13 by driving the throttle valve 14, the injector 16, the variable valve mechanism 25, the ignition circuit unit 33 and the like by executing program processing based on detection signals of various sensors. To do.

[Configuration of ignition device]
Next, the configuration of the ignition device 30 will be described with reference to FIG.
As shown in FIG. 2, the ignition device 30 includes a spark plug 31, an ignition coil 32, an ignition switch 40, a current detection circuit 41, an energy input unit 42, and an electronic control unit 34. The ignition switch 40, the current detection circuit 41, and the energy input unit 42 are included in the ignition circuit unit 33. The ignition circuit unit 33 and the electronic control unit 34 constitute an ignition control device 5.

  The spark plug 31 has a pair of electrodes facing each other with a predetermined gap in the combustion chamber 17 of the engine 13, and discharges when a high voltage sufficient to cause dielectric breakdown is applied between the pair of electrodes. generate. In the following description, “high voltage” refers to a voltage that can generate a discharge between a pair of electrodes of the spark plug 31, that is, a voltage that enables a discharge to be generated.

  The ignition coil 32 includes a primary winding 43, a secondary winding 44, and a rectifying element 45, and constitutes a known step-up transformer. The primary winding 43 has one end connected to the DC power supply 46 and the other end grounded via the ignition switch 40. The DC power source 46 is constituted by a battery and can supply a constant DC voltage such as 12V. The secondary winding 44 is magnetically coupled to the primary winding 43, one end is grounded via a pair of electrodes of the spark plug 31, and the other end is grounded via a rectifier element 45 and a current detection resistor 47. Has been. The rectifying element 45 is composed of a diode and rectifies the direction of the current flowing through the secondary winding 44. The ignition coil 32 generates a high voltage in the secondary winding 44 by the mutual induction action of electromagnetic induction in accordance with a change in the current flowing through the primary winding 43, and applies this high voltage to the spark plug 31. In the present embodiment, only one ignition coil 32 is provided corresponding to one spark plug. In the following description, the current flowing through the primary winding 43 is “primary current I1”, and the current flowing through the secondary winding 44 is “secondary current I2”.

  The ignition switch 40 is composed of an IGBT, a collector is connected to the ground side of the primary winding 43 of the ignition coil 32, an emitter is grounded, and a gate is connected to the electronic control unit 34. The emitter is connected to the collector via a rectifying element 48. The ignition switch 40 opens and closes according to the ignition signal IGT input to the gate. Specifically, the ignition switch 40 is turned on when the ignition signal IGT rises and turned off when the ignition signal IGT falls. The ignition signal IGT is, for example, a conduction and interruption signal for the primary winding 43 that is controlled in synchronization with the cam position. The current path between the DC power supply 46 and the primary winding 43 is switched between conduction and interruption by the ignition switch 40.

The current detection circuit 41 is connected between the rectifying element 45 and the current detection resistor 47, and can detect the secondary current I2.
The energy input unit 42 includes a choke coil 51, a charge switch 52, a charge switch drive circuit 53, a capacitor 54, a rectifier element 55, a discharge switch 56, a rectifier element 57, and a discharge switch drive circuit 58.

  The choke coil 51 has one end connected to the DC power supply 46 and the other end grounded via the charging switch 52. The charge switch 52 is composed of a MOSFET, the drain is connected to the choke coil 51, the source is grounded, and the gate is connected to the charge switch drive circuit 53. The charge switch drive circuit 53 can drive the charge switch 52 to open and close.

  The capacitor 54 has one electrode connected to the ground side of the choke coil 51 via the rectifying element 55 and the other electrode grounded. The rectifying element 55 is composed of a diode, and prevents a backflow of current from the capacitor 54 to the choke coil 51 and the charging switch 52. The choke coil 51, the charging switch 52, the capacitor 54, and the rectifying element 55 constitute a boosting circuit that boosts and charges the voltage of the DC power supply 46.

  The capacitor 54 has one electrode connected to the ground side of the primary winding 43 via the discharge switch 56 and the rectifying element 57. The discharge switch 56 is composed of a MOSFET, the drain is connected to the capacitor 54, the source is connected to the ground side of the primary winding 43, and the gate is connected to the discharge switch drive circuit 58. The discharge switch drive circuit 58 can open and close the discharge switch 56. The rectifying element 57 is composed of a diode, and prevents a backflow of current from the ignition coil 32 to the capacitor 54.

  Here, there are two ways to flow the secondary current I2 for discharging the spark plug 31. First, the energization from the DC power supply 46 to the primary winding 43 is interrupted by the ignition switch 40, so that an electromotive force larger than the voltage of the DC power supply 46 is instantaneously generated by the primary winding due to the self-induction action of electromagnetic induction. In this manner, a high voltage is generated in the secondary winding 44 by the mutual induction action of electromagnetic induction, and discharge is started. Second, by closing the discharge switch 56 of the energy input unit 42 and applying the charging voltage of the capacitor 54 to the primary winding 43, an electromotive force larger than the charging voltage can be generated from the secondary winding by the mutual induction action of electromagnetic induction. In this method, the current is generated on the line 44 and superimposed on the discharge current. In the following description, “electric energy input by the energy input unit 42 to the spark plug 31” refers to the electric power generated by the spark plug 31 as a result of applying the charging voltage of the capacitor 54 of the energy input unit 42 to the primary winding 43. It means energy.

  In the present embodiment, the ignition control device 5 generates the discharge only by the first method described above, and generates the discharge by the first method described above, and then generates the discharge during the discharge. In the second method, ignition is performed using different cases in which electric energy is applied in a superimposed manner while maintaining the same discharge current polarity to continue discharge. Hereinafter, the discharge in the former case is referred to as “normal discharge”, and the discharge in the latter case is referred to as “continuous discharge”. In addition, a period in which the discharge is continued by supplying electric energy is described as a continuation period Tc.

  The charge switch drive circuit 53 opens and closes the charge switch 52 according to the continuous discharge count signal IGC and the ignition signal IGT output from the electronic control unit 34. The continuous discharge count signal IGC is a signal for instructing ignition by continuous discharge and a signal for instructing the number of times of ignition by continuous discharge. Specifically, the charge switch drive circuit 53 can detect the capacitor voltage Vdc, which is the voltage of the capacitor 54, and if the capacitor voltage Vdc is equal to or lower than a predetermined threshold value Vdc_th when the continuous discharge count signal IGC rises, 52 is turned on to start charging the capacitor 54. The charge switch drive circuit 53 turns on the charge switch 52 to charge the capacitor 54 when the continuous discharge count signal IGC is rising and the capacitor voltage Vdc is equal to or lower than the threshold value Vdc_th when the ignition signal IGT rises. Start. When the charging switch 52 is turned on, energy is stored in the choke coil 51, and when the charging switch 52 is turned off, the energy released from the choke coil 51 is charged in the capacitor 54. The capacitor voltage Vdc is boosted by repeating the charging switch 52 ON and OFF. Charging of the capacitor 54 is terminated when the capacitor voltage Vdc reaches a predetermined maximum voltage Vdc_max or the ignition signal IGT falls.

The discharge switch driving circuit 58 opens and closes the discharge switch 56 in accordance with the duration signal IGW and the target secondary current signal IGA output from the electronic control unit 34. The duration signal IGW is a signal that indicates the duration Tc. The target secondary current signal IGA is a signal for instructing a target secondary current I2 ^* that is a target value of the secondary current I2 in the duration Tc. Specifically, the discharge switch drive circuit 58 opens and closes the discharge switch 56 so that the secondary current I2 detected by the current detection circuit 41 matches the target secondary current I2 ^* while the duration signal IGW rises. To drive. When the discharge switch 56 is turned on, the charging energy of the capacitor 54 is input to the ground side of the primary winding 43.

  The electronic control unit 34 determines an injection amount setting unit 61 that sets the fuel injection amount of the injector 16, a fuel cut state in which the injector 16 stops fuel injection, and a return from the fuel cut state. The fuel cut recovery determination unit 62, the ignition switch control unit 63 that controls the ignition switch 40, and the energy control unit 64 that controls the energy input unit 42 are provided.

  The injection amount setting unit 61 outputs a drive signal IND for operating the drive circuit 59 of the injector 16. The drive signal IND is generated so that the fuel injection amount of the injector 16 matches the target injection amount. The target injection amount is set based on the operating state of the engine 13 determined from the detection signals of various sensors. For example, when the vehicle is decelerated, the fuel injection state is set by setting the target injection amount to zero. Further, when the vehicle is accelerated or when the output speed Ne of the engine 13 is equal to or less than a predetermined threshold value Ne_th, the target injection amount is increased from 0 and the fuel cut state is restored.

The fuel cut return determination unit 62 determines that the fuel cut state is reached when the target injection amount is zero, and determines that the fuel cut state returns when the target injection amount increases from zero. The fuel cut return determination unit 62 corresponds to “fuel cut return determination means” recited in the claims.
The ignition switch control unit 63 outputs an ignition signal IGT for controlling the opening / closing operation of the ignition switch 40. The ignition signal IGT is raised at a predetermined timing before the ignition timing (ignition timing) determined based on the cam position, for example, and is lowered to the ignition timing.

The energy control unit 64 outputs a continuous discharge count signal IGC, a target secondary current signal IGA, and a duration signal IGW for controlling driving of the energy input unit 42. The continuous discharge count signal IGC is raised when the return from the fuel cut state is determined. The target secondary current signal IGA is generated according to the target secondary current I2 ^* . In the present embodiment, the target secondary current I2 ^* is set in advance to a predetermined value. The duration signal IGW is raised at the start of the duration Tc, and is lowered at the end of the duration Tc. In the present embodiment, the duration period Tc is set in advance to a predetermined time. Further, the continuation period Tc is started after the discharge due to the ignition switch 40 being turned off.

  Further, assuming that the ignition timing interval is the ignition cycle Tig, the energy control unit 64 supplies electric energy to the energy input unit 42 until the ignition cycle Tig has passed the predetermined number of executions Nc after the return from the fuel cut state is determined. Command to turn on. In the present embodiment, the number of executions Nc is set to 3 times, for example. The continuous discharge count signal IGC is raised to a signal indicating that the number of ignitions due to the remaining continuous discharge is “3 times” when the return from the fuel cut state is determined. Every time it passes, it is changed to a signal indicating “2 times”, “1 time”, or “0 times”. The energy control unit 64 corresponds to “energy control means” described in the claims.

[Control operation of electronic control unit]
Next, control processing of the electronic control unit 34 will be described with reference to the flowchart of FIG. The series of processing shown in FIG. 3 is repeatedly executed from when the ignition switch is turned on until it is turned off.
In step S110, it is determined whether a return from the fuel cut state has been detected. If the determination in step S110 is affirmative (S110: Yes), the process proceeds to step S120. On the other hand, when the determination in step S110 is negative (S110: No), the process proceeds to step S160.

  In step S120, the continuous discharge count signal IGC is output, and the charge switch drive circuit 53 opens and closes the charge switch 52 to start boosting the capacitor voltage Vdc. After step S120, the process proceeds to step S130.

In step S130, it is determined whether or not it is an ignition timing. The timing when the ignition signal IGT falls is the ignition timing. If the determination in step S130 is affirmative (S130: Yes), the process proceeds to step S140. On the other hand, when the determination in step S130 is negative (S130: No), step S130 is repeatedly executed.
In step S140, continuous discharge control for generating continuous discharge is performed. After step S140, the process proceeds to step S150.

  In step S150, it is determined whether or not the continuous discharge has been performed a predetermined number of times Nc after returning from the fuel cut state. If the determination in step S150 is affirmative (S150: Yes), the routine shown in FIG. 3 is exited. On the other hand, when the determination in step S150 is negative (S150: No), the process returns to step S130.

In step S160, it is determined whether it is an ignition timing. If the determination in step S160 is affirmative (S160: Yes), the process proceeds to step S170. On the other hand, when the determination in step S160 is negative (S160: No), step S160 is repeatedly executed.
In step S170, normal discharge control for generating normal discharge is performed. After step S170, the process exits the routine shown in FIG.

[Operation of ignition control device]
Next, the operation of the ignition control device 5 will be described with reference to the time chart of FIG.
In the following description, a signal output from the charge switch drive circuit 53 to the gate of the charge switch 52 is referred to as a charge switch drive signal SWC. A signal output from the discharge switch drive circuit 58 to the gate of the discharge switch 56 is a discharge switch drive signal SWD. Further, the ignition signal IGT, the duration signal IGW, the charge switch drive signal SWC, and the discharge switch drive signal SWD are signals whose signal level becomes a high level “H” or a low level “L”. Further, the continuous discharge count signal IGC is a signal whose signal level is changed in four stages of 3 level “3”, 2 level “2”, 1 level “1”, and 0 level “0”.

As shown in FIG. 4, at time t1 when the ignition signal IGT becomes the high level “H”, the ignition switch 40 is turned on and the primary current I1 starts to increase. At this time, since the continuous discharge count signal IGC is at the 0 level “0”, the next discharge is set to the normal discharge.
At the time t <b> 2 when the ignition signal IGT becomes the low level “L”, the ignition switch 40 is turned OFF and a high voltage is generated in the secondary winding 44. As a result, a discharge occurs in the spark plug 31, and the secondary current I2 increases. After this discharge, the discharge is not continued due to the input of electric energy, and the secondary current I2 gradually decreases.

At the time t3 when the output rotation speed Ne becomes equal to or less than the threshold value Ne_th, the continuous discharge count signal IGC becomes the three level “3”. As a result, charging of the capacitor 54 is started, and the capacitor voltage Vdc increases. The charge switch drive signal SWC is not particularly limited in pulse width and cycle as long as the charge switch 52 can be driven to open and close so that sufficient charging energy is charged in the capacitor.
At time t4 when the ignition signal IGT becomes the high level “H”, the ignition switch 40 is turned on. At this time, since the continuous discharge count signal IGC is 3 level “3”, the next discharge is set to the continuous discharge.

At time t <b> 5 when the ignition signal IGT becomes the low level “L”, the ignition switch 40 is turned OFF and a high voltage is generated in the secondary winding 44. As a result, a discharge occurs in the spark plug 31, and the secondary current I2 increases.
After the discharge by the ignition switch 40, at time t6 when the continuous discharge signal IGC is received, the continuous period signal IGW becomes the high level “H”, and the electric energy input by the energy input unit 42 is started. Thereby, the secondary current I2 increases and the discharge is continued. The secondary current I2 is feedback-controlled by supplying electric energy so that the detected value by the current detection circuit 41 matches the target secondary current I2 ^* during the duration Tc.

At time t7 when the continuation period Tc elapses from time t6 and the continuation period signal IGW becomes low level “L”, the electric energy input by the energy input unit 42 is stopped, and the continuous discharge control is ended.
Thereafter, from time t8 to time t15 when the continuous discharge count signal IGC becomes 0 level “0”, the same operation as that from time t4 to time t8 is repeatedly performed.
At time t16 when the ignition signal IGT is at the high level “H”, the continuous discharge count signal IGC is at the 0 level “0”, so that the discharge from the next time t17 is set to normal discharge.

[effect]
As described above, in the first embodiment, the ignition control device 5 includes the ignition coil 32, the ignition switch 40, the energy input unit 42, the ignition plug 31, and the electronic control unit 34. The energy input unit 42 is connected to the ground side of the primary winding 43, and continues discharging by supplying electric energy to the spark plug 31. The fuel cut return determination unit 63 of the electronic control unit 34 determines return from the fuel cut state. Further, the energy control unit 64 of the electronic control unit 34 commands the energy input unit 42 to input electric energy until the ignition cycle Tig has passed the number of executions Nc after the return from the fuel cut state is determined.

  The ignition performance of the air-fuel mixture increases as the energy input unit 42 inputs electric energy. Therefore, when the energy input unit 42 supplies electric energy when returning from the fuel cut state, the mixture can be reliably ignited even when the manifold wet becomes less than usual and the mixture becomes thin. . Thereby, the correction amount of the fuel injection amount when returning from the fuel cut state can be reduced, or the correction itself can be eliminated. Therefore, according to this embodiment, the fuel consumption improvement effect by fuel cut control can be heightened.

In the first embodiment, the energy input unit 42 continues the discharge by applying electric energy in a superimposed manner during the generation of the discharge by the ignition switch 40.
By comprising in this way, the ignition performance of air-fuel mixture improves and misfire can be further suppressed.

Second Embodiment
An ignition control apparatus according to a second embodiment of the present invention will be described with reference to FIG.
In the second embodiment, the energy control unit 64 of the electronic control unit 34 sets the number of executions Nc based on the water temperature Tw of the engine 13. Specifically, the energy control unit 64 increases the number of executions Nc as the water temperature Tw is lower according to the map shown in FIG.
According to 2nd Embodiment, the effect similar to 1st Embodiment can be acquired, and also the fall of ignition performance when the water temperature Tw is low can be suppressed.

<Third Embodiment>
An ignition control apparatus according to a third embodiment of the present invention will be described with reference to FIGS.
In the third embodiment, the energy control unit 64 of the electronic control unit 34 sets the number of executions Nc based on the fuel cut duration Tcut that is the time during which the fuel cut state has been continued. As shown in FIG. 6, the fuel cut continuation time Tcut is the threshold value Ne_th from the time t1 when the fuel cut is started when the throttle opening is fully closed and the vehicle is decelerated. This is the time until the time t2 when the fuel cut state is restored. Specifically, the energy control unit 64 increases the number of executions Nc as the fuel cut duration Tcut is longer according to the map shown in FIG.
According to the third embodiment, it is possible to obtain the same effect as that of the first embodiment, and it is possible to suppress a decrease in ignition performance when the fuel cut duration time Tcut is long.

<Fourth embodiment>
An ignition control apparatus according to a fourth embodiment of the present invention will be described with reference to FIGS.
In the fourth embodiment, the energy control unit 64 of the electronic control unit 34 controls the discharge energy Wc based on the water temperature Tw of the engine 13 when the electric energy input by the energy input unit 42 at one ignition cycle Tig is the discharge energy Wc. To do. Specifically, the energy control unit 64 increases the discharge energy Wc as the water temperature Tw is lower as shown in FIG. In this embodiment, the relationship that the discharge energy Wc is increased as the duration Tc is longer is used, and the duration Tc is set longer as the water temperature Tw is lower according to the map shown in FIG.
By changing the discharge energy Wc in this way, electric energy can be used as much as necessary when necessary, and energy saving can be achieved.

<Fifth Embodiment>
An ignition control apparatus according to a fifth embodiment of the present invention will be described with reference to FIG.
In the fifth embodiment, the energy control unit 64 of the electronic control unit 34 uses the relationship that the discharge energy Wc increases as the target secondary current I2 ^* increases, and the lower the water temperature Tw according to the map shown in FIG. The target secondary current I2 ^* is set large.
Thus, the discharge energy Wc can also be changed by changing the target secondary current I2 ^* .

<Sixth Embodiment>
An ignition control apparatus according to a sixth embodiment of the present invention will be described with reference to FIGS.
In the sixth embodiment, the energy control unit 64 of the electronic control unit 34 sets the duration Tc longer as the water temperature Tw is lower according to the map shown in FIG. 9, and the water temperature Tw is lower according to the map shown in FIG. 10. The target secondary current I2 ^* is set to be larger.
Thus, by changing both the duration Tc and the target secondary current I2 ^* , the discharge energy Wc can be controlled more finely.

<Seventh embodiment>
An ignition control apparatus according to a seventh embodiment of the present invention will be described with reference to FIGS.
In the seventh embodiment, the energy control unit 64 of the electronic control unit 34 controls the discharge energy Wc based on the fuel cut duration Tcut. Specifically, as shown in FIG. 11, the energy control unit 64 increases the discharge energy Wc as the fuel cut duration Tcut is longer. In the present embodiment, the relationship that the discharge energy Wc increases as the duration Tc becomes longer is used, and the duration Tc is set longer as the fuel cut duration Tcut becomes longer according to the map shown in FIG.
By changing the discharge energy Wc in this way, electric energy can be used as much as necessary when necessary, and energy saving can be achieved.

<Eighth Embodiment>
An ignition control apparatus according to an eighth embodiment of the present invention will be described with reference to FIG.
In the eighth embodiment, the energy control unit 64 of the electronic control unit 34 decreases the discharge energy Wc every time the ignition cycle Tig elapses as shown in FIG.
By changing the discharge energy Wc in this way, electric energy can be used as much as necessary when necessary, and energy saving can be achieved.

<Ninth Embodiment>
An ignition control apparatus according to a ninth embodiment of the present invention will be described with reference to FIG.
In the ninth embodiment, the injection amount setting unit 61 of the electronic control unit 34 functions as an injection amount correction unit that performs correction to increase the amount of fuel injected by the injector 16 when it is determined that the fuel cut state has been restored. The energy control unit 64 of the electronic control unit 34 controls the discharge energy Wc based on the fuel correction amount described above. Specifically, as shown in FIG. 14, the energy control unit 64 increases the discharge energy Wc as the fuel correction amount Qr decreases. Discharge energy Wc is increased or decreased by changing one or both of duration Tc and target secondary current I2 ^* .
By changing the discharge energy Wc in this way, electric energy can be used as much as necessary when necessary, and energy saving can be achieved.

<Other embodiments>
In another embodiment of the present invention, the number of executions may be controlled based on both the engine water temperature and the fuel cut duration.
In other embodiments of the present invention, the discharge energy may be controlled based on both engine water temperature and fuel cut duration.

In the above-described embodiment, the secondary current I2 is feedback-controlled by opening and closing the discharge switch 56 so that the value detected by the current detection circuit 41 matches the target secondary current I2 ^* . On the other hand, in another embodiment of the present invention, the secondary current I2 is controlled by opening and closing the discharge switch 56 by a drive signal set from, for example, a map or the like regardless of the feedback value from the current detection circuit. May be.
In another embodiment of the present invention, the energy input unit may alternately and repeatedly perform charging and discharging during the occurrence of continuous discharge, that is, during the continuous period.

  In the above-described embodiment, only one ignition coil 32 and one ignition switch 40 are provided corresponding to one ignition plug 31, and the energy input unit 42 supplies electric energy during discharge generated by turning off the ignition switch 40. The discharge was continued by superimposing it. On the other hand, in another embodiment of the present invention, two ignition coils and two ignition switches are provided corresponding to one spark plug, and the energy input unit is charged with a discharge generated when one of the ignition switches is turned off. Discharge may be generated by supplying electric energy to the spark plug via one ignition coil after the interruption. The energy input unit may generate electric discharge by supplying electric energy to the spark plug via the other ignition coil after the discharge generated by turning off the other ignition switch is interrupted. And you may continue discharge by making the said discharge continuous. Further, in another embodiment of the present invention, two ignition coils and two ignition switches are provided corresponding to one ignition plug, the discharge generated when one ignition switch is turned off, and the other ignition switch being turned off. The discharge may be continued by continuing the discharge generated by. In such a configuration, the other ignition switch functions as an “energy input unit”.

In other embodiments of the present invention, the ignition circuit unit may be housed in a housing that houses the electronic control unit, or may be housed in a housing that houses the ignition coil.
In other embodiments of the present invention, the ignition switch and the energy input may be housed in separate housings. For example, the ignition switch may be housed in a housing that houses the ignition coil, and the energy input unit may be housed in the housing that houses the electronic control unit.

In another embodiment of the present invention, the ignition switch may be composed of another transistor instead of the IGBT.
In other embodiments of the present invention, the charge switch may be composed of other transistors such as IGBTs.
In other embodiments of the present invention, the discharge switch may be composed of other transistors such as IGBTs.
In another embodiment of the present invention, the direct current power source is not limited to a battery, for example, a direct current stabilized power source in which an alternating current power source is stabilized by a switching regulator or the like, or a battery voltage boosted by a DC-DC converter or the like. It may be configured.

  In the above-described embodiment, the energy input unit 42 includes the choke coil 51, the charge switch 52, the charge switch drive circuit 53, the capacitor 54, and the rectifying element 55 as a DC-DC converter that boosts the voltage of the DC power supply 46 and stores it. Had. On the other hand, in another embodiment of the present invention, the energy input unit does not include a choke coil, a charge switch, a charge switch drive circuit, a capacitor, and a rectifier, and is connected to a high voltage battery provided in, for example, a hybrid car. The energy may be supplied from the high voltage battery.

In the above-described embodiment, the electronic control unit 34 collectively has means for driving the throttle valve 14, the injector 16, the variable valve mechanism 25, the ignition switch 40, and the energy input unit 42. On the other hand, in another embodiment of the present invention, the means for driving the ignition switch and the energy input unit, that is, the ignition switch control unit, the fuel cut return determination unit, and the energy control unit include a throttle valve, an injector, and a variable valve mechanism. It may be provided in a unit different from the driving means.
The present invention is not limited to the embodiments described above, and can be implemented in various forms without departing from the spirit of the invention.

5 ... Ignition control device 13 ... Engine (internal combustion engine)
17 ... Combustion chamber 30 ... Ignition device 31 ... Ignition plug 32 ... Ignition coil 40 ... Ignition switch 42 ... Energy input part 43 ... Primary winding 44 ... Secondary Winding 46 ... DC power supply (power supply)
63 ... Fuel cut return determination section (fuel cut return determination means)
64 ・ ・ ・ Energy control unit (energy control means)
Tig ... Ignition cycle

Claims (7)

The ignition device (30) for igniting the air-fuel mixture in the combustion chamber (17) of the internal combustion engine (13) is configured, and the secondary winding (44) is energized and cut off by the primary winding (43) of the ignition coil (32). An ignition control device (5) for generating a high voltage at a spark plug and generating a discharge with a spark plug (31) connected to the secondary winding,
An ignition switch (40) capable of switching between conduction and interruption of a current path between a power source and the primary winding, and generating a high voltage in the secondary winding by interrupting the current path;
An energy input unit (42) connected to the primary winding or the spark plug and capable of supplying electric energy to the spark plug to allow the discharge to continue;
When the fuel injection device of the internal combustion engine stops the fuel injection as a fuel cut state, fuel cut return determination means (63) for determining return from the fuel cut state;
Assuming that the ignition timing interval of the spark plug is an ignition cycle (Tig), when it is determined that the fuel cut state is restored, the energy input is performed until the predetermined number of executions (Nc) of the ignition cycle elapses from the determination. Energy control means (64) for instructing the unit to input electric energy;
Equipped with a,
The energy control means sets the number of executions based on either or both of a coolant temperature (Tw) of the cooling water of the internal combustion engine and a duration (Tcut) of the fuel cut state. . 2. The ignition control according to claim 1, wherein the energy control unit increases the electric energy (Wc) input by the energy input unit in one ignition cycle as the coolant temperature of the internal combustion engine is lower. apparatus. 3. The ignition control device according to claim 1, wherein the energy control unit increases the electric energy input by the energy input unit in one ignition cycle as the duration of the fuel cut state is longer. The ignition according to any one of claims 1 to 3 , wherein the energy control means reduces the electric energy input by the energy input unit in one ignition cycle each time the ignition cycle elapses. Control device. An injection amount correction means (61) for performing correction to increase the amount of fuel injected by the fuel injection device when it is determined that the fuel cut state has been returned;
Said energy control means the higher the correction amount by the injection quantity compensation means (Qr) is small, it claims 1-4, wherein the energy supplying portion is characterized by increasing the electric energy to be charged in one ignition cycle The ignition control device according to one item. Only one ignition coil is provided corresponding to one spark plug,
The ignition switch generates a discharge in the spark plug by interrupting the current path in accordance with the ignition timing of the spark plug,
The ignition control device according to any one of claims 1 to 5 , wherein the energy input unit continues the discharge by superimposing electric energy while the discharge by the ignition switch is being generated. . When the current flowing through the secondary winding is a secondary current (I2),
The energy input unit can control the secondary current to a target secondary current (I2 ^* ) commanded from the energy control unit during a duration (Tc) commanded from the energy control unit;
Said energy control means, by changing one or both of the duration and the target secondary current, according to claim 6, wherein the energy supplying portion is characterized by changing the electric energy to be introduced by the ignition cycle Ignition control device according to.

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