JP6375674B2 - Control device - Google Patents

Description

  The present invention relates to a control device, and more particularly to a control device that controls an ignition device of an internal combustion engine.

  Conventionally, a control device that controls an ignition device of an internal combustion engine and controls ignition of an air-fuel mixture in a combustion chamber is known. For example, in the control device described in Patent Document 1, the discharge time of the spark plug is measured, and the operation of the internal combustion engine is switched based on the measured discharge time.

JP 2008-88948 A

  In the control device of Patent Document 1, when the discharge time becomes equal to or less than a predetermined threshold during the lean operation of the internal combustion engine, the operation is switched to the stoichiometric operation in order to prevent misfire. As a result, stable drivability is ensured. Here, if the current flowing through the secondary coil of the ignition coil during discharge of the ignition plug is detected, it is considered that the abnormality of the ignition coil can be detected based on the detected current value and the threshold value. However, in the control device of Patent Document 1, no consideration is given to the abnormality detection of the ignition device. For this reason, when the ignition device is abnormal, there is a possibility that the fuel consumption, emission, and drivability deteriorate, or that the vehicle cannot be retreated.

  By the way, an ignition device having an energy input unit capable of maintaining a discharge state by continuously supplying electric energy to an ignition coil after starting discharge control of the spark plug is known. In this ignition device, regarding the current flowing through the secondary coil, the current value detected during normal discharge of the spark plug may differ from the current value detected when electric energy is applied to the ignition coil after the discharge. Therefore, when the control device of Patent Document 1 is applied to the ignition device having such a configuration and abnormality is detected by the above-described method, even if the abnormality of the ignition coil can be detected with one threshold value, Abnormality may not be detected.

  The present invention has been made in view of the above-described problems, and an object thereof is to provide a control device capable of detecting an abnormality of an ignition device with a simple configuration.

  The present invention controls an ignition device including an ignition plug, an ignition coil, an igniter unit, and an energy input unit, and can control ignition of an air-fuel mixture in a combustion chamber of an internal combustion engine. Means and an abnormality detection means. Here, the spark plug is provided in the combustion chamber of the internal combustion engine, and can ignite the air-fuel mixture in the combustion chamber by discharging. The ignition coil has a primary coil having one end connected to the power supply side and the other end connected to the ground side, and a secondary coil having one end connected to the spark plug. The igniter portion is provided so as to allow or block the flow of current from the primary coil to the ground side. The energy input unit can input electric energy to the ignition coil.

The control unit includes a discharge control unit and an energy input control unit, and can control ignition of the air-fuel mixture in the combustion chamber.
The discharge control means controls the igniter so as to cut off the flow of current from the primary coil to the ground side, thereby generating a high voltage in the secondary coil and controlling the discharge of the spark plug so that the spark plug is discharged . Thereby, the spark plug is discharged, and the air-fuel mixture can be ignited.

The energy input control unit controls the energy input unit so as to input electric energy to the ignition coil after starting the discharge control of the spark plug by the discharge control unit. Thereby, the discharge state of the spark plug generated by the control of the discharge control means can be maintained. Therefore, the ignitability of the air-fuel mixture can be improved.
The current detection means can detect a current flowing through the secondary coil.
The abnormality detection means can detect an abnormality of the ignition device based on a current value that is a value corresponding to the current detected by the current detection means.

In the present invention, the abnormality detection means provides a determination waiting time after starting the discharge control of the spark plug by the discharge control means , and when the first predetermined period which is the first predetermined period as the determination waiting time has elapsed, other than 0 Based on the first threshold value that is the first threshold value and the first current value that is the value corresponding to the current detected by the current detection means at this time, the absolute value of the first current value is greater than the absolute value of the first threshold value. smaller, it detects an abnormality of the igniter or igniter coil.

As described above, in the present invention, the abnormality detection unit can detect an abnormality in the igniter unit or the ignition coil based on the current value and the threshold value detected after the discharge control of the ignition plug is started by the discharge control unit. Thereby, the abnormality of the ignition device can be detected with a simple configuration.

  In the present invention, the abnormality detection means, for example, when the second predetermined period, which is a second predetermined period longer than the first predetermined period, elapses after the start of control of the spark plug by the discharge control means. Based on the second threshold value, which is a threshold value, and the second current value, which is a value corresponding to the current detected by the current detection means at this time, an abnormality in the energy input unit can be detected. In this configuration, the current value (first current value, second current value) detected by the time difference after the start of control of the spark plug by the discharge control means and the two threshold values (first threshold value, second threshold value) are detected by the abnormality detection means. Based on the above, it is possible to distinguish and detect an abnormality in the igniter part or the ignition coil or an abnormality in the energy input part. Thereby, the abnormality of each part which comprises an ignition device can be distinguished and detected with a simple structure. Therefore, the operation of the internal combustion engine can be switched according to the part where the abnormality is detected.

The figure which shows the control apparatus by 1st Embodiment of this invention, and the engine system to which this is applied. The figure which shows the circuit structure of the control apparatus by 1st Embodiment of this invention. The flowchart which shows a part of process regarding the ignition control of the air-fuel | gaseous mixture and abnormality detection by the control apparatus of 1st Embodiment of this invention. The flowchart which shows a part of process regarding the ignition control of the air-fuel | gaseous mixture and abnormality detection by the control apparatus of 1st Embodiment of this invention. The flowchart which shows a part of process regarding the ignition control of the air-fuel | gaseous mixture and abnormality detection by the control apparatus of 1st Embodiment of this invention. The figure for demonstrating the 1st operation example of the control apparatus and ignition device of 1st Embodiment of this invention. The figure for demonstrating the 2nd operation example of the control apparatus and ignition device of 1st Embodiment of this invention. The figure for demonstrating the 3rd operation example of the control apparatus and ignition device of 1st Embodiment of this invention. It is a figure for demonstrating the operation example of the control apparatus and ignition device of 2nd Embodiment of this invention, Comprising: (A) is a figure before change of a current target value and a 2nd threshold value, (B) is a current target value. The figure after the change of a 2nd threshold value.

Hereinafter, control devices according to a plurality of embodiments of the present invention will be described with reference to the drawings. Note that, in a plurality of embodiments, substantially the same components are denoted by the same reference numerals, and description thereof is omitted.
(First embodiment)
A control device according to a first embodiment of the present invention is shown in FIGS. The control device 10 is applied to the engine system 1 and can control each unit constituting the engine system 1.

The engine system 1 includes an engine 20 as an internal combustion engine, an ignition device 11 and the like.
The engine 20 is a premixed combustion type four-cylinder engine driven by, for example, gasoline as fuel. The engine 20 includes a cylinder 21, an engine head 22, an intake valve 25, an exhaust valve 26, a piston 27, a crankshaft 29, and the like.

The cylinder 21 is formed in a cylindrical shape. In the present embodiment, four cylinders 21 are formed in the engine 20. The engine head 22 is provided so as to close one end of the cylinder 21. The engine head 22 is formed with an intake port 23 and an exhaust port 24 that communicate with the inner space of the cylinder 21.
The intake valve 25 is provided so as to be able to open and close between the intake port 23 and the inner space of the cylinder 21. The exhaust valve 26 is provided so as to be able to open and close between the exhaust port 24 and the inner space of the cylinder 21.

  The piston 27 is provided so as to reciprocate in the axial direction inside the cylinder 21. A combustion chamber 28 is formed by the inner wall of the cylinder 21, the engine head 22, and the piston 27. When the gas in which fuel and air are mixed, that is, the air-fuel mixture burns in the combustion chamber 28, the volume of the combustion chamber 28 increases and the piston 27 moves to the side opposite to the engine head 22. When the air-fuel mixture burns in the combustion chamber 28, combustion gas is generated.

  The crankshaft 29 is rotatably provided by the reciprocating movement of the piston 27. When fuel burns in the combustion chamber 28 and the piston 27 reciprocates in the cylinder 21, the crankshaft 29 rotates and torque is output from the crankshaft 29. Torque output from the crankshaft 29 is transmitted to a vehicle wheel (not shown). Thereby, the vehicle travels.

  An intake pipe 31 is connected to the intake port 23 of the engine head 22. An intake passage 32 is formed inside the intake pipe 31. One end of the intake passage 32 is open to the atmosphere, and the other end is connected to the intake port 23. Thus, the atmosphere (air) is supplied to the combustion chamber 28 via the intake passage 32 and the intake port 23. Hereinafter, air supplied from the atmosphere side to the combustion chamber 28 of the engine 20 will be referred to as intake air.

  A throttle valve 2 is provided in the intake passage 32. The throttle valve 2 can be opened and closed by being driven to rotate by the actuator 3. That is, the throttle valve 2 can change the amount of intake air supplied to the combustion chamber 28 by opening and closing the intake passage 32.

  A fuel injection valve 4 is provided in the vicinity of the engine head 22 of the intake pipe 31. The fuel injection valve 4 can inject fuel into the intake port 23. As a result, an air-fuel mixture of fuel and intake air (air) is supplied to the combustion chamber 28. The fuel injection valve 4 can change the amount of fuel to be injected by controlling the opening and closing of the injection hole. That is, the fuel injection valve 4 can change the amount of fuel supplied to the combustion chamber 28.

  An exhaust pipe 33 is connected to the exhaust port 24 of the engine head 22. An exhaust passage 34 is formed inside the exhaust pipe 33. The exhaust passage 34 has one end connected to the exhaust port 24 and the other end open to the atmosphere. Thereby, the air containing the combustion gas generated in the combustion chamber 28 is discharged to the atmosphere side through the exhaust port 24 and the exhaust passage 34. Hereinafter, the air containing the combustion gas discharged from the combustion chamber 28 of the engine 20 is referred to as exhaust as appropriate. In the present embodiment, a three-way catalyst 35 is provided in the exhaust passage 34. The three-way catalyst 35 purifies the exhaust discharged to the atmosphere side by oxidizing or reducing hydrocarbons, carbon monoxide, and nitrogen oxides in the exhaust.

  In the present embodiment, the engine system 1 includes an EGR pipe 36 that connects the intake pipe 31 and the exhaust pipe 33. An EGR passage 37 is formed inside the EGR pipe 36. The EGR passage 37 communicates the exhaust passage 34 and the intake passage 32. As a result, the exhaust in the exhaust passage 34 can be recirculated to the intake passage 32 via the EGR passage 37.

  An EGR valve device 5 is provided in the EGR pipe 36. The EGR valve device 5 can open and close the EGR passage 37 by an EGR valve (not shown). That is, the EGR valve device 5 can change the amount of exhaust gas recirculated from the exhaust passage 34 to the intake passage 32 by opening and closing the EGR passage 37.

Here, the EGR pipe 36 and the EGR valve device 5 constitute an exhaust gas recirculation (EGR) system that supplies exhaust gas discharged from the combustion chamber 28 of the engine 20 to the combustion chamber 28 together with intake air. . By supplying the exhaust gas to the combustion chamber 28 together with the intake air, it is possible to reduce nitrogen oxides in the exhaust gas exhausted to the atmosphere, improve the fuel consumption, and the like.
The ignition device 11 is provided for igniting the air-fuel mixture introduced into the combustion chamber 28. As shown in FIG. 2, the ignition device 11 includes a spark plug 40, an ignition coil 50, an igniter section 60, an energy input section 70, and the like.

  Four spark plugs 40 are provided so as to correspond to each of the four cylinders 21. The spark plug 40 has a discharge part 41. The discharge part 41 has a center electrode 42 and a ground electrode 43. A predetermined gap is formed between the center electrode 42 and the ground electrode 43. The spark plug 40 is provided in the engine head 22 so that the discharge part 41 is exposed to the combustion chamber 28 (see FIG. 1). The ground electrode 43 is electrically connected to the engine head 22. That is, the ground electrode 43 is grounded. The spark plug 40 discharges between the center electrode 42 of the discharge part 41 and the ground electrode 43 by the applied voltage, and can ignite the air-fuel mixture in the combustion chamber 28.

  Four ignition coils 50 are provided so as to correspond to each of the four spark plugs 40 (cylinders 21). The ignition coil 50 is provided on the engine head 22 so that one end thereof is connected to the side opposite to the discharge part 41 of the spark plug 40 (see FIG. 1). The ignition coil 50 has a primary coil 51, a secondary coil 52, a core 53, and a diode 54 (see FIG. 2).

  The primary coil 51 is formed by winding a copper wire around the core 53 a predetermined number of times, for example, and one end is connected to the positive electrode of the power source 12. The power source 12 is a low-voltage battery that can output a voltage of about ten and several volts from the positive electrode, and the negative electrode is grounded (body earth). The other end of the primary coil 51 is the ground side.

The secondary coil 52 is formed, for example, by winding a copper wire around the core 53 a predetermined number of times, and one end is connected to the center electrode 42 of the spark plug 40 and the other end is grounded. Here, the number of turns of the secondary coil 52 is set to be larger than that of the primary coil 51.
The core 53 is made of a material having a magnetic permeability of a predetermined value or more, such as iron.

  The diode 54 is provided on the side opposite to the spark plug 40 with respect to the secondary coil 52. The diode 54 is provided such that the anode side is connected to the secondary coil 52 and the cathode side is grounded. As a result, a current flow from the secondary coil 52 to the ground side via the diode 54 is allowed, and a current flow from the ground side to the secondary coil 52 side via the diode 54 is blocked.

  Four igniter portions 60 are provided so as to correspond to each of the four ignition coils 50 (cylinders 21). The igniter section 60 is provided on the opposite side of the power supply 12 with respect to the primary coil 51 of the ignition coil 50 (see FIG. 2). The igniter unit 60 includes a switching element 61 and a diode 62.

  In the present embodiment, the switching element 61 is, for example, an IGBT (Insulated Gate Bipolar Transistor). The switching element 61 is provided such that the collector is connected to the primary coil 51 and the emitter is grounded. The switching element 61 performs a switching operation based on a signal input to the gate so that the switching element 61 is turned on or off. The switching element 61 allows a current flow from the primary coil 51 to the ground side via the switching element 61 when in the on state, and from the primary coil 51 to the ground side via the switching element 61 when in the off state. Cut off current flow.

  The diode 62 has an anode connected to the emitter of the switching element 61, that is, grounded. The diode 62 is connected to the collector of the switching element 61 on the cathode side, that is, to the primary coil 51. Thereby, the flow of current from the ground side to the primary coil 51 side via the diode 62 is allowed, and the current flow from the primary coil 51 side to the ground side via the diode 62 is blocked.

  When the switching element 61 of the igniter unit 60 is in the on state, the current from the power source 12 flows to the ground side via the primary coil 51 and the switching element 61 of the ignition coil 50. At this time, the core 53 is magnetized to store magnetic energy, and a magnetic field is formed around it. When the current flows through the primary coil 51 and the switching element 61 is turned off, the current flow from the primary coil 51 to the ground side is cut off, the magnetic field around the core 53 changes, and the primary induction occurs due to the self-induction action. A voltage of about several hundred volts is generated in the coil 51. At this time, a high voltage of about several tens of kV is also generated in the secondary coil 52 sharing the magnetic circuit and the magnetic flux. At this time, the voltage generated in the secondary coil 52 has a magnitude proportional to the number of turns of the primary coil 51 and the secondary coil 52. When a high voltage is generated in the secondary coil 52, the potential difference between the center electrode 42 of the spark plug 40 and the ground electrode 43 becomes a predetermined value or more. As a result, dielectric breakdown occurs between the center electrode 42 and the ground electrode 43, and the spark plug 40 discharges between the center electrode 42 and the ground electrode 43.

Hereinafter, as appropriate, the current flowing through the primary coil 51 is referred to as a primary current I1, the current flowing through the secondary coil 52 is referred to as a secondary current I2, and the voltage of the secondary coil 52 is referred to as a secondary voltage V2. The direction from the power supply 12 side to the igniter 60 side is the positive direction of the primary current I1, and the direction from the diode 54 side to the spark plug 40 side is the positive direction of the secondary current I2. Further, the secondary voltage V2 when the secondary current I2 in the positive direction flows through the secondary coil 52 is a positive voltage.
In the present embodiment, when the spark plug 40 is discharged, the secondary voltage V2 is a negative voltage, and a secondary current I2 in the negative direction flows through the secondary coil 52.

In the present embodiment, one energy input unit 70 is provided for the four ignition coils 50. The energy input unit 70 is provided in parallel with the primary coil 51 between the power supply 12 and the igniter unit 60 (see FIG. 2). The energy input unit 70 includes a coil 71, switching elements 72 and 73, diodes 74 and 75, a capacitor 76, and driver circuits 77 and 78.
The coil 71 is formed, for example, by winding a copper wire a predetermined number of times, and one end thereof is provided so as to be connected between the power supply 12 and the primary coil 51.

  In the present embodiment, the switching elements 72 and 73 are a kind of field effect transistor MOSFET (metal-oxide-semiconductor field-effect transistor). The switching element 72 is provided such that the drain is connected to the other end of the coil 71 and the source is grounded. The switching element 73 is provided such that the drain is connected to the capacitor 76 and the source is connected between the primary coil 51 of the ignition coil 50 and the igniter unit 60 via the diode 75. In the present embodiment, four switching elements 73 are provided corresponding to each of the four ignition coils 50 (cylinders 21), but the present invention is not limited to this.

  The switching elements 72 and 73 perform a switching operation based on a signal input to the gate so that the switching elements 72 and 73 are turned on or off. When the switching element 72 is in the on state, the switching element 72 allows a current to flow from the coil 71 to the ground side via the switching element 72. When the switching element 72 is in the off state, the current flows from the coil 71 to the ground side via the switching element 72. Cut off the flow. Switching element 73 allows current flow from capacitor 76 to primary coil 51 and igniter section 60 via switching element 73 when in the on state, and from capacitor 76 via switching element 73 when in the off state. The current flow to the primary coil 51 and the igniter unit 60 side is cut off.

  The diode 74 is provided so that the anode side is connected between the coil 71 and the switching element 72 and the cathode side is connected to the capacitor 76. Thereby, the flow of current from the coil 71 and switching element 72 side to the capacitor 76 via the diode 74 is allowed, and the current flow from the capacitor 76 to the coil 71 and switching element 72 side via the diode 74 is blocked. ing.

  The diode 75 is provided such that the anode side is connected to the source of the switching element 73 and the cathode side is connected between the primary coil 51 and the igniter unit 60. Thereby, the flow of current from the switching element 73 side to the primary coil 51 and the igniter section 60 side via the diode 75 is allowed, and from the primary coil 51 and igniter section 60 side to the switching element 73 side via the diode 75. Current flow is interrupted. In the present embodiment, four diodes 75 are provided corresponding to each of the four switching elements 73.

  The driver circuit 77 generates a switching signal SWc related to the switching operation of the switching element 72 based on the input signal, and outputs the generated switching signal SWc to the gate of the switching element 72. Here, the switching signal SWc is a signal indicating OFF (Lo) or ON (Hi). When the switching signal SWc is off, the switching element 72 is turned off, and when the switching signal SWc is on, the switching element 72 is turned on. As described above, the switching element 72 performs a switching operation based on the switching signal SWc input from the driver circuit 77.

  The driver circuit 78 generates a switching signal SWd related to the switching operation of the switching element 73 based on the input signal, and outputs the generated switching signal SWd to the gate of the switching element 73. Here, the switching signal SWd is a signal indicating OFF (Lo) or ON (Hi). When the switching signal SWd is off, the switching element 73 is turned off, and when the switching signal SWd is on, the switching element 73 is turned on. As described above, the switching element 73 performs a switching operation based on the switching signal SWd input from the driver circuit 78. In the present embodiment, four driver circuits 78 are provided corresponding to each of the four switching elements 73.

When the switching element 73 is off and the switching element 72 is on, the current from the power source 12 flows to the ground side via the coil 71 and the switching element 72. At this time, electrical energy is stored in the coil 71. When the current flows through the coil 71, if the switching element 72 is turned off, the current flow from the coil 71 to the ground side is interrupted. As a result, electric energy is released from the coil 71 and supplied to the capacitor 76 via the diode 74. Therefore, when the switching operation is performed so that the switching element 73 is turned off and the switching element 72 is repeatedly turned on or off alternately, electric energy is gradually accumulated from the coil 71 to the capacitor 76. At this time, the voltage Vdc at one end of the capacitor 76 gradually increases. When the electric energy is stored in the capacitor 76, and when the switching element 61 of the igniter unit 60 is turned off and the switching element 73 is turned on, the electric energy of the capacitor 76 passes through the switching element 73 and the diode 75. , Is supplied (input) to the primary coil 51 of the corresponding ignition coil 50. As described above, the energy input unit 70 can store the electric energy from the power source 12 in the capacitor 76 and can input it to the ignition coil 50. In the present embodiment, the energy input unit 70 ignites so that the secondary current I2 having the same polarity as the secondary current I2 flowing through the secondary coil 52 when the spark plug 40 is discharged, that is, the secondary current I2 in the negative direction is superimposed. Electric energy is input to the coil 50.
In the present embodiment, the igniter unit 60 and the energy input unit 70 described above are accommodated in the casing of the ignition circuit unit 13 (see FIG. 2).

As shown in FIG. 2, the control device 10 includes a control unit 81, a current detection circuit 91, an abnormality detection unit 93, and the like.
In the present embodiment, the control unit 81 is housed in a housing of an electronic control unit (hereinafter referred to as “ECU”) 80.
The control unit 81 is, for example, a microcomputer, and includes a CPU as arithmetic means, a ROM and RAM as storage means, a timer as time measurement means, I / O as input / output means, and the like. The control unit 81 performs operations according to a program stored in the ROM based on signals from sensors provided in each part of the vehicle, and controls the operation of devices and devices in each part of the vehicle, thereby integrating the vehicle. Can be controlled.

  As shown in FIG. 1, in this embodiment, a throttle opening sensor 6 is provided in the vicinity of the throttle valve 2 of the intake pipe 31. The throttle opening sensor 6 detects the opening of the throttle valve 2 in the intake passage 32 and outputs a signal correlated with the detected opening to the control unit 81. Thereby, the control part 81 can detect the opening degree of the throttle valve 2.

  An air flow meter 7 is provided on the side opposite to the engine 20 with respect to the throttle valve 2 of the intake pipe 31. The air flow meter 7 detects the amount of intake air flowing through the intake passage 32, that is, the amount of intake air supplied to the combustion chamber 28 of the engine 20, and outputs a signal correlated to the detected amount of intake air to the control unit 81. Thus, the control unit 81 can detect the amount of intake air supplied to the combustion chamber 28.

  An intake pressure sensor 8 is provided in a surge tank between the throttle valve 2 of the intake pipe 31 and the engine 20. The intake pressure sensor 8 detects the pressure (intake pressure) of the intake air flowing through the intake passage 32 and outputs a signal correlated with the detected pressure to the control unit 81. Thereby, the control unit 81 can detect the intake pressure.

  A cam position sensor 9 is provided in the vicinity of the cam shaft of the engine head 22. The cam position sensor 9 detects the rotational position of the camshaft that drives the exhaust valve 26 or the intake valve 25 to open and close, and outputs a signal correlated to the detected rotational position to the control unit 81. Thereby, the control unit 81 can detect the rotational position of the camshaft. Therefore, the control unit 81 can perform cam angle calculation, cylinder discrimination, and the like.

  The engine 20 is provided with a crank position sensor 14 in the vicinity of the crankshaft 29. The crank position sensor 14 detects the rotational position of the crankshaft 29 and outputs a signal correlated with the detected rotational position to the control unit 81. Thereby, the control unit 81 can detect the rotational position of the crankshaft 29. Therefore, the control unit 81 can calculate the crank angle and the rotation speed of the crankshaft 29, that is, the rotation speed of the engine 20.

  Further, the engine 20 is provided with a water temperature sensor 15 in the cylinder 21. The water temperature sensor 15 detects the temperature (water temperature) of the cooling water that cools the cylinder 21 and outputs a signal correlated to the detected temperature to the control unit 81. Thereby, the control unit 81 can detect the temperature of the cooling water.

  An A / F sensor 16 is provided between the engine 20 in the exhaust pipe 33 and the three-way catalyst 35. The A / F sensor 16 detects the air-fuel ratio in the engine 20 from the concentration of oxygen in the exhaust gas flowing through the exhaust passage 34 and the concentration of unburned gas, and outputs a signal correlated with the detected air-fuel ratio to the control unit 81. . Thereby, the control unit 81 can detect the air-fuel ratio in the engine 20.

An O ₂ sensor 17 is provided on the opposite side of the exhaust pipe 33 from the engine 20 with respect to the three-way catalyst 35. In the O ₂ sensor 17, the air-fuel ratio in the engine 20 is thicker than the stoichiometric air-fuel ratio from the electromotive force generated by the difference between the oxygen concentration in the atmosphere and the oxygen concentration in the exhaust gas flowing through the exhaust passage 34. Whether the state is (rich) or thin (lean) is detected, and a signal (rich signal or lean signal) corresponding to the detected state is output to the control unit 81. As a result, the control unit 81 can detect whether the air-fuel ratio in the engine 20 is richer or lighter than the stoichiometric air-fuel ratio.

The power supply 12 is provided with a voltage sensor 18. The voltage sensor 18 detects the voltage of the power supply 12 and outputs a signal correlated with the detected voltage to the control unit 81. Thereby, the control unit 81 can detect the voltage of the power supply 12.
The EGR valve device 5 outputs a signal correlated with the opening degree of the EGR valve in the EGR passage 37 to the control unit 81. Thereby, the control part 81 can detect the opening degree of an EGR valve.

  The control unit 81 operates the ignition device 11 including the ignition plug 40 and the ignition coil 50, the actuator 3 of the throttle valve 2, the fuel injection valve 4, the EGR valve device 5 and the like based on the signals from the various sensors described above. By controlling this, the operation of the engine 20 can be controlled.

In this embodiment, the current detection circuit 91 is accommodated in the casing of the ignition circuit unit 13 (see FIG. 2). The ignition circuit unit 13 is provided with a resistor 92. The resistor 92 is provided such that one end is connected to the cathode side of the diode 54 of the ignition coil 50 and the other end is grounded. The current detection circuit 91 is provided so as to be connected between the diode 54 and the resistor 92. Thereby, the current detection circuit 91 can detect the current flowing from the diode 54 to the ground side, that is, the secondary current I2 flowing through the secondary coil 52. Here, the current detection circuit 91 corresponds to “current detection means” in the claims.
In this embodiment, the abnormality detection unit 93 is accommodated in the casing of the ignition circuit unit 13 (see FIG. 2). A current value corresponding to the secondary current I2 detected by the current detection circuit 91 is input to the abnormality detection unit 93.

Next, control of the ignition device 11 by the control unit 81 and ignition control of the air-fuel mixture in the combustion chamber 28 will be described.
The control unit 81 controls the igniter unit 60 so as to cut off the flow of current from the primary coil 51 to the ground side, thereby generating a high voltage in the secondary coil 52 and causing the ignition plug 40 to discharge. Control. Specifically, the control unit 81 controls the spark plug 40 by outputting the ignition signal IGt to the gate of the switching element 61 of the igniter unit 60. Here, the ignition signal IGt is a signal indicating off (Lo) or on (Hi). When the ignition signal IGt is off, the switching element 61 is turned off, and the flow of current (primary current I1) from the primary coil 51 to the ground side via the switching element 61 is interrupted. On the other hand, when the ignition signal IGt is on, the switching element 61 is turned on, and a current flow from the primary coil 51 to the ground side via the switching element 61 is allowed.

  When the ignition signal IGt changes from on to off, the flow of the primary current I1 flowing through the primary coil 51 is interrupted, and a high voltage is generated in the secondary coil 52. As a result, the spark plug 40 discharges (ignites) between the center electrode 42 and the ground electrode 43 of the discharge part 41. As a result, the mixture in the combustion chamber 28 is ignited (ignited).

  In this way, the control unit 81 generates the ignition signal IGt and outputs the ignition signal IGt to the switching element 61 of the igniter unit 60 so that the ignition plug 40 is discharged at the timing when the ignition signal IGt falls from on to off. The plug 40 can be controlled. Here, the control unit 81 corresponds to “discharge control means” in the claims. The timing at which the ignition signal IGt falls from on to off is assumed to be when the control of the spark plug 40 by the “discharge control means” starts (the start of the control period).

  Further, the control unit 81 controls the energy input unit 70 so as to input electric energy to the ignition coil 50 after starting the control of the spark plug 40 by the “discharge control means”. Specifically, the control unit 81 controls the energy input unit 70 by controlling the switching element 73 by outputting the energy input period signal IGw to the driver circuit 78. Here, the energy input period signal IGw is a signal indicating OFF (Lo) or ON (Hi). The energy input period signal IGw is generated so as to rise from off to on after the ignition signal IGt falls from on to off, that is, after the control of the spark plug 40 by the “discharge control means” is started.

  The driver circuit 78 outputs the switching signal SWd to the gate of the switching element 73 while the energy input period signal IGw is on. Thereby, the switching element 73 performs a switching operation so that the energy input period signal IGw is in the on state or the off state during the on period.

  When the switching element 73 is in the on state, the electrical energy stored in the capacitor 76 is input to the ground side of the primary coil 51 of the ignition coil 50 via the switching element 73 and the diode 75. Here, the control unit 81 corresponds to “energy input control means” in the claims.

  When the energy input unit 70 is controlled by the “energy input control means” and electric energy is input to the ground side of the primary coil 51 of the ignition coil 50, an induced current (secondary current I 2) is applied to the secondary coil 52 of the ignition coil 50. Arise. This induced current corresponds to electrical energy capable of maintaining the discharge state of the spark plug 40 generated by the control of the “discharge control means”. That is, it can be considered that “the energy input unit 70 inputs electric energy to the spark plug 40”.

  In the present embodiment, after the switching element 73 in the on state is changed to the off state, the input of electric energy from the capacitor 76 is cut off, but for a predetermined period, it passes through the diode 62 due to the inductance of the primary coil 51. When the current flows from the ground side, the primary current I1 is not cut off and the secondary current I2 is not cut off. Therefore, at this time (until a predetermined period elapses after the switching element 73 in the on state changes to the off state), the discharge state of the spark plug 40 can be maintained.

  In the present embodiment, the “energy input control unit” feeds back the value of the secondary current I2 detected by the current detection circuit 91 so that the current corresponding to the current target value IGa that is a predetermined current value is secondary. For example, the energy input unit 70 is controlled by controlling the duty ratio of the switching signal SWd (ratio of the ON period to the switching period) so as to flow through the coil 52. Thus, during the period when the energy input unit 70 supplies electric energy to the ignition coil 50, the secondary current I2 that substantially corresponds to the current target value IGa flows through the secondary coil 52.

  The control unit 81 stores the electric energy in the capacitor 76 by controlling the switching element 72 via the driver circuit 77 before the electric energy is input to the ignition coil 50 by the “energy input control unit”. To do. Specifically, the driver circuit 77 outputs the switching signal SWc to the gate of the switching element 72 before the energy input period signal IGw is turned on, for example, during the period when the ignition signal IGt is on. Thereby, the switching element 72 performs a switching operation so as to be in an on state or an off state, for example, while the ignition signal IGt is on. As a result, electric energy is stored in the capacitor 76.

  In the present embodiment, the control unit 81 has “normal ignition control means” that controls ignition of the air-fuel mixture in the combustion chamber 28 only by controlling the spark plug 40 by “discharge control means”. In the ignition control of the air-fuel mixture by the “normal ignition control means”, electric energy is not input to the ignition coil 50 by the energy input unit 70, so that the discharge of the spark plug 40 is completed in a relatively short time. Therefore, the ignition control of the air-fuel mixture by the “normal ignition control means” is suitable in the case where the air-fuel mixture in the combustion chamber 28 is easily ignited (ignited).

  Further, the control unit 81 controls the ignition plug 40 by the “discharge control unit” and controls the ignition of the air-fuel mixture in the combustion chamber 28 by controlling the energy input unit 70 by the “energy input control unit”. It has “specific ignition control means”. In the ignition control of the air-fuel mixture by the “specific ignition control means”, electric energy is input to the ignition coil 50 by the energy input unit 70, so that the discharge of the spark plug 40 lasts for a relatively long time. Therefore, the ignition control of the air-fuel mixture by the “specific ignition control means” is suitable when the air-fuel mixture in the combustion chamber 28 is difficult to be ignited (ignited).

  The controller 81 determines the ease of ignition of the air-fuel mixture in the combustion chamber 28 according to, for example, the operating state of the engine 20 and the environmental conditions, and based on the determination result, the ignition control of the air-fuel mixture by the “normal control means” The air-fuel mixture ignition control by the “specific ignition control means” can be switched.

Next, abnormality detection of the igniter unit 60, the ignition coil 50, or the energy input unit 70 by the control unit 81 and the abnormality detection unit 93 will be described.
The control unit 81 (abnormality detection unit 93) has a first threshold value that is a first threshold value when a first predetermined period Tp1 that is a first predetermined period has elapsed after the start of control of the spark plug 40 by the “discharge control means”. Based on the threshold value Th1 and the first current value Id1 that is a value corresponding to the current (secondary current I2) detected by the current detection circuit 91 at this time, an abnormality in the igniter unit 60 or the ignition coil 50 can be detected. Specifically, the abnormality detection unit 93 indicates that an abnormality has occurred in the igniter unit 60 or the ignition coil 50 when the absolute value of the first current value Id1 input from the current detection circuit 91 is smaller than the first threshold Th1. Is output to the control unit 81. In this case, the control unit 81 detects an abnormality in the igniter unit 60 or the ignition coil 50.

Further, the control unit 81 (abnormality detection unit 93), when the second predetermined period Tp2, which is a second predetermined period longer than the first predetermined period Tp1, has elapsed after the start of the control of the spark plug 40 by the "discharge control means". Based on the second threshold value Th2 that is the second threshold value and the second current value Id2 that is a value corresponding to the current (secondary current I2) detected by the current detection circuit 91 at this time, the abnormality of the energy input unit 70 Can be detected. Specifically, the abnormality detection unit 93 indicates that an abnormality has occurred in the energy input unit 70 when the absolute value of the second current value Id2 input from the current detection circuit 91 is smaller than the second threshold Th2. The detection signal IGf is output to the control unit 81. In this case, the control unit 81 detects an abnormality in the energy input unit 70.
Here, the control unit 81 and the abnormality detection unit 93 correspond to “abnormality detection means” in the claims.
In the present embodiment, the second threshold Th2 is set to a value that is larger than the first threshold Th1 and smaller than the current target value IGa.

Next, ignition control of the air-fuel mixture in the combustion chamber 28 by the control unit 81 will be described with reference to FIGS.
The control unit 81 performs ignition control of the air-fuel mixture in the combustion chamber 28 by executing a series of processes S100 shown in FIGS. In addition, the control unit 81 performs a series of processes S100 to perform ignition control of the air-fuel mixture in the combustion chamber 28, and the abnormality detection unit 93 detects an abnormality in the igniter unit 60, the ignition coil 50, or the energy input unit 70. It can be detected. A series of processing S100 is started, for example, when the ignition key of the vehicle is turned on.

  In S101, the control unit 81 determines whether or not to start energization of the primary coil 51 of the ignition coil 50. If it is determined that energization of the primary coil 51 should be started (S101: YES), the process proceeds to S102. On the other hand, when it is determined that energization of the primary coil 51 should not be started (S101: NO), the process returns to S101. That is, S101 is a process repeated until it is determined that energization of the primary coil 51 should be started.

  In S102, the control unit 81 turns on the ignition signal IGt output to the switching element 61 of the igniter unit 60. Accordingly, the switching element 61 is turned on, and energization (primary current I1) to the primary coil 51 of the ignition coil 50 is started. After S102, the process proceeds to S103.

  In S103, the control unit 81 determines whether or not it is time to ignite the air-fuel mixture. Specifically, the control unit 81 calculates a crank angle based on, for example, a signal from the crank position sensor 14 and determines a timing at which the air-fuel mixture should be ignited. When it is determined that it is time to ignite the air-fuel mixture (S103: YES), the process proceeds to S104. On the other hand, when it is determined that it is not time to ignite the air-fuel mixture (S103: NO), the process returns to S103. That is, S103 is a process that is repeated until it is determined that it is time to ignite the air-fuel mixture.

  In S104, the control unit 81 turns off the ignition signal IGt. As a result, the switching element 61 is turned off, and the current flow from the primary coil 51 to the ground side is interrupted. As a result, a high voltage is generated in the secondary coil 52, and discharge of the spark plug 40 is started. That is, the control of the spark plug 40 by the “discharge control means” is started. As a result, the mixture is ignited (ignited) and combustion of the mixture starts. After S104, the process proceeds to S105.

  In S <b> 105, the control unit 81 determines whether it is necessary to input electric energy to the ignition coil 50 by the energy input unit 70. Specifically, the control unit 81 determines the ease of ignition of the air-fuel mixture in the combustion chamber 28 according to, for example, the operating state of the engine 20 and the environmental conditions, and the electric energy of the ignition coil 50 is determined based on the determination result. Judgment is made on the necessity. When it is determined that it is necessary to input electric energy to the ignition coil 50 (S105: YES), the process proceeds to S106. In this case, the control unit 81 performs the ignition control of the air-fuel mixture by the “specific ignition control unit”. On the other hand, when it is determined that it is not necessary to input electric energy to the ignition coil 50 (S105: NO), the process proceeds to S120. In this case, the control unit 81 performs the ignition control of the air-fuel mixture by the “normal ignition control means”.

  In S <b> 106, the controller 81 sets an electric energy input period for the ignition coil 50, that is, an energy input period. Specifically, the control unit 81 sets the on period (the width of the on state) of the energy input period signal IGw based on, for example, the operating state of the engine 20 and environmental conditions. After S106, the process proceeds to S107.

  In S107, the control unit 81 (abnormality detection unit 93) sets the first threshold value Th1 and the second threshold value Th2. Here, the control unit 81 sets the second threshold Th2 to a value larger than the first threshold Th1. After S107, the process proceeds to S108.

  In S108, the control unit 81 (abnormality detection unit 93) sets the first predetermined period Tp1 and the second predetermined period Tp2. Here, the control unit 81 sets the second predetermined period Tp2 to a period longer than the first predetermined period Tp1. After S108, the process proceeds to S109.

  In S109, the control unit 81 turns on the energy input period signal IGw. As a result, the switching element 73 performs a switching operation, and the input of electric energy from the energy input unit 70 to the ignition coil 50 is started. That is, the control of the energy input unit 70 by the “energy input control means” is started. Thereby, the discharge state of the spark plug 40 generated by the control of the “discharge control means” is maintained thereafter. After S109, the process proceeds to S110.

  In S110, the control unit 81 (abnormality detection unit 93) determines whether or not the first predetermined time Tp1 has elapsed since the start of the control of the spark plug 40 by the “discharge control means”, that is, the execution of S104. Judging. When it is determined that the first predetermined time Tp1 has elapsed (S110: YES), the process proceeds to S111. On the other hand, when it is determined that the first predetermined time Tp1 has not elapsed (S110: NO), the process returns to S110. That is, S110 is a process (delay process) that is repeated until it is determined that the first predetermined time Tp1 has elapsed since the start of the control of the spark plug 40 by the “discharge control means”.

  In S111, the abnormality detection unit 93 determines whether the value corresponding to the current (secondary current I2) detected by the current detection circuit 91 at this time, that is, whether the absolute value of the first current value Id1 is greater than or equal to the absolute value of the first threshold Th1. Judge whether or not. When it is determined that the absolute value of the first current value Id1 is greater than or equal to the absolute value of the first threshold Th1 (S111: YES), the process proceeds to S112. On the other hand, when it is determined that the absolute value of the first current value Id1 is smaller than the absolute value of the first threshold Th1 (S111: NO), the abnormality detection unit 93 indicates that an abnormality has occurred in the igniter unit 60 or the ignition coil 50. An abnormality detection signal IGf shown is output to the control unit 81, and the process proceeds to S118.

  In S112, the control unit 81 (abnormality detection unit 93) determines whether or not the second predetermined time Tp2 has elapsed since the start of the control of the spark plug 40 by the “discharge control means”, that is, the execution of S104. Judging. When it is determined that the second predetermined time Tp2 has elapsed (S112: YES), the process proceeds to S113. On the other hand, when it is determined that the second predetermined time Tp2 has not elapsed (S112: NO), the process returns to S112. That is, S112 is a process (delay process) that is repeated until it is determined that the second predetermined time Tp2 has elapsed since the start of the control of the spark plug 40 by the “discharge control means”.

In S113, the abnormality detection unit 93 determines whether the value corresponding to the current (secondary current I2) detected by the current detection circuit 91 at this time, that is, whether the absolute value of the second current value Id2 is greater than or equal to the absolute value of the second threshold Th2. Judge whether or not. When it is determined that the absolute value of the second current value Id2 is greater than or equal to the absolute value of the second threshold Th2 (S113: YES), the process proceeds to S114. On the other hand, when it is determined that the absolute value of the second current value Id2 is smaller than the absolute value of the second threshold Th2 (S113: NO), the abnormality detection unit 93 detects abnormality in the energy input unit 70. The signal IGf is output to the control unit 81, and the process proceeds to S117.
In S114, the control unit 81 determines that “the igniter unit 60, the ignition coil 50, and the energy input unit 70 are all normal”. After S114, the process proceeds to S115.

  In S115, the control unit 81 starts the control of the energy input unit 70 by the “energy input control means”, that is, after the energy input period signal IGw is turned on in S109, the energy input period set in S106 is determined. Judge whether or not it has passed. If it is determined that the energy input period has elapsed (S115: YES), the process proceeds to S116. On the other hand, when it is determined that the energy input period has not elapsed (S115: NO), the process returns to S115. That is, S115 is a process (delay process) that is repeated until it is determined that the energy input period has elapsed after the control of the energy input unit 70 by the “energy input control means” is started.

In S <b> 117, the control unit 81 determines that “an abnormality has occurred in the energy input unit 70”, that is, detects an abnormality in the energy input unit 70. After S117, the process proceeds to S116.
In S118, the control unit 81 determines that “an abnormality has occurred in the igniter unit 60 or the ignition coil 50”, that is, detects an abnormality in the igniter unit 60 or the ignition coil 50. After S118, the process proceeds to S116.

In S116 executed after S115, S117, and S118, the control unit 81 turns off the energy input period signal IGw. As a result, the switching operation of the switching element 73 is stopped, and the input of electrical energy from the energy input unit 70 to the ignition coil 50 is stopped. That is, the control of the energy input unit 70 by the “energy input control means” is stopped. After S116, the process exits the series of S100.
In S120, the control unit 81 (abnormality detection unit 93) sets the first threshold Th1. After S120, the process proceeds to S121.
In S121, the control unit 81 (abnormality detection unit 93) sets the first predetermined period Tp1. After S121, the process proceeds to S122.

  In S122, the control unit 81 (abnormality detection unit 93) determines whether or not the first predetermined time Tp1 has elapsed since the start of the control of the spark plug 40 by the “discharge control means”, that is, the execution of S104. Judging. When it is determined that the first predetermined time Tp1 has elapsed (S122: YES), the process proceeds to S123. On the other hand, when it is determined that the first predetermined time Tp1 has not elapsed (S122: NO), the process returns to S122. That is, S122 is a process (delay process) that is repeated until it is determined that the first predetermined time Tp1 has elapsed since the start of the control of the spark plug 40 by the “discharge control means”.

  In S123, the abnormality detection unit 93 determines whether the value corresponding to the current (secondary current I2) detected by the current detection circuit 91 at this time, that is, whether the absolute value of the first current value Id1 is equal to or greater than the absolute value of the first threshold Th1. Judge whether or not. If it is determined that the absolute value of the first current value Id1 is greater than or equal to the absolute value of the first threshold Th1 (S123: YES), the process proceeds to S124. On the other hand, when it is determined that the absolute value of the first current value Id1 is smaller than the absolute value of the first threshold Th1 (S123: NO), the abnormality detecting unit 93 indicates that an abnormality has occurred in the igniter unit 60 or the ignition coil 50. An abnormality detection signal IGf shown is output to the control unit 81, and the process proceeds to S125.

In S124, the control unit 81 determines that “the igniter unit 60 and the ignition coil 50 are normal”. After S124, the process exits the series of processes S100.
In S125, the control unit 81 determines that “an abnormality has occurred in the igniter unit 60 or the ignition coil 50”, that is, detects an abnormality in the igniter unit 60 or the ignition coil 50. After S125, the process exits the series of processes S100.

  After S116, S124 or S125, when exiting the series of processes S100, if the ignition key is on, the series of processes S100 is started again. That is, the series of processes S100 is a process that is repeatedly executed while the ignition key is on.

  As described above, when it is determined in S105 that it is necessary to input electric energy to the ignition coil 50 (S105: YES), the ignition control of the air-fuel mixture is performed by the “specific ignition control means”. On the other hand, when it is determined in S105 that it is not necessary to supply electric energy to the ignition coil 50 (S105: NO), the ignition control of the air-fuel mixture is performed by the “normal ignition control means”.

  Further, the control unit 81 (abnormality detection unit 93) detects the abnormality of the igniter unit 60 or the ignition coil 50 or the abnormality of the energy input unit 70 when the ignition control of the air-fuel mixture is performed by the “specific ignition control unit”. It can be distinguished and detected. On the other hand, the control unit 81 (abnormality detection unit 93) can detect an abnormality in the igniter unit 60 or the ignition coil 50 when the ignition control of the air-fuel mixture is performed by the “normal ignition control unit”.

Next, an operation example of the control device 10 and the ignition device 11 controlled by the control device 10 will be described with reference to FIGS.
FIG. 6 shows a first operation example (first operation example). The first operation example is an operation example when the igniter unit 60, the ignition coil 50, and the energy input unit 70 are all normal.

  When the control unit 81 determines that energization of the primary coil 51 of the ignition coil 50 should be started at time t11 (S101: YES), the ignition signal IGt is turned on (S102). Thereby, energization (primary current I1) to primary coil 51 is started. In the present embodiment, the driver circuit 77 of the energy input unit 70 outputs the switching signal SWc that changes to ON or OFF to the switching element 72 during the period when the ignition signal IGt is ON (time t11 to 12). Therefore, the switching element 72 performs a switching operation so as to be in an on state or an off state while the ignition signal IGt is on. As a result, electric energy is accumulated in the capacitor 76.

  When the control unit 81 determines that it is time to ignite the air-fuel mixture at time t12 (S103: YES), the ignition signal IGt is turned off (S104). As a result, a secondary voltage V2, which is a negative voltage, is generated in the secondary coil 52, the absolute value of the secondary voltage V2 becomes equal to or greater than a predetermined value, and the spark plug 40 is connected to the center electrode 42 and the ground electrode of the discharge part 41. 43 is discharged. As a result, the mixture in the combustion chamber 28 is ignited (ignited). At this time, the secondary current I2 in the negative direction flows through the secondary coil 52, and the absolute value of the secondary current I2 becomes a predetermined value or more. When the spark plug 40 is discharged at time t12, the absolute value of the secondary voltage V2 quickly becomes equal to or less than a predetermined value. As the spark plug 40 is discharged, the absolute value of the secondary current I2 gradually decreases from time t12 to time t13.

  When the control unit 81 turns on the energy input period signal IGw at time t13 (S109), the driver circuit 78 of the energy input unit 70 outputs the switching signal SWd that changes to on or off to the switching element 73. Thereby, the input of electric energy from the energy input unit 70 to the ignition coil 50 is started. The switching element 73 performs a switching operation so that the energy input period signal IGw is in an on state or an off state during an on period (time t13 to 16). Therefore, electric energy is input from the energy input unit 70 to the ignition coil 50 during the period from time t13 to time t16. Thereby, the secondary current I2 having the same polarity as that of the secondary current I2 flowing through the secondary coil 52 when the spark plug 40 is discharged, that is, a negative secondary current I2 is superimposed. As a result, the discharge state of the spark plug 40 generated at time t12 is maintained.

  In the present embodiment, the “energy input control means” feeds back the value of the secondary current I2 detected by the current detection circuit 91, so that the current corresponding to the current target value IGa flows through the secondary coil 52. In order to control the charging unit 70, as shown in FIG. 6, during the period when the energy charging period signal IGw is on (time t13 to 16), the secondary coil 52 has a secondary current I2 that substantially corresponds to the current target value IGa. (Average value is IGa) flows.

  When the first predetermined period Tp1 has elapsed from time t12 when the spark plug 40 is started to be controlled by the “discharge control means” (time t14), the control unit 81 and the abnormality detection unit 93 set the first threshold Th1 at this time. Based on the first current value Id1 corresponding to the secondary current I2 detected by the current detection circuit 91, it is determined whether or not an abnormality has occurred in the igniter unit 60 or the ignition coil 50. In the first operation example shown in FIG. 6, since the absolute value of the first current value Id1 is equal to or greater than the absolute value of the first threshold value Th1, “no abnormality has occurred in the igniter 60 or the ignition coil 50”, that is, “igniter” It is determined that the unit 60 and the ignition coil 50 are normal.

  When the second predetermined period Tp2 has elapsed from time t12 when the spark plug 40 is started to be controlled by the “discharge control means” (time t15), the control unit 81 and the abnormality detection unit 93 are set to the second threshold Th2. Based on the second current value Id2 corresponding to the secondary current I2 detected by the current detection circuit 91, it is determined whether or not an abnormality has occurred in the energy input unit 70. In the first operation example shown in FIG. 6, since the absolute value of the second current value Id2 is equal to or greater than the absolute value of the second threshold Th2, “no abnormality has occurred in the energy input unit 70”, that is, “the energy input unit 70 Is normal. "

  When the control unit 81 turns off the energy input period signal IGw at time t16 (S116), the switching operation of the switching element 73 is stopped, and the input of electric energy from the energy input unit 70 to the ignition coil 50 is stopped. Thereby, the discharge of the spark plug 40 is stopped at time t17, and the secondary current I2 and the secondary voltage V2 become zero.

FIG. 7 shows a second operation example (second operation example). The second operation example is an operation example in the case where an abnormality has occurred only in the energy input unit 70.
Since time t21 to time 23 are the same as time t11 to time 13 of the first operation example, description thereof is omitted.

  When the control unit 81 turns on the energy input period signal IGw at time t23 (S109), the driver circuit 78 of the energy input unit 70 outputs the switching signal SWd that changes to on or off to the switching element 73. However, in the second operation example, since an abnormality has occurred in the energy input unit 70, the input of electric energy from the energy input unit 70 to the ignition coil 50 is not started. While the energy input period signal IGw is on (time t23 to 26), the switching element 73 remains on because the secondary current I2 does not reach the current target value IGa, but the period from time t23 to 26 is Electric energy is not input from the energy input unit 70 to the ignition coil 50. Therefore, after time t23, the absolute value of the secondary current I2 gradually decreases, the discharge of the spark plug 40 stops at time t25, and the secondary current I2 becomes zero.

  When the first predetermined period Tp1 has elapsed from time t22 when the ignition plug 40 is started to be controlled by the “discharge control means” (time t24), the control unit 81 and the abnormality detection unit 93 set the first threshold Th1 and the Based on the first current value Id1 corresponding to the secondary current I2 detected by the current detection circuit 91, it is determined whether or not an abnormality has occurred in the igniter unit 60 or the ignition coil 50. In the second operation example shown in FIG. 7, since the absolute value of the first current value Id1 is equal to or larger than the absolute value of the first threshold value Th1, “no abnormality has occurred in the igniter 60 or the ignition coil 50”, that is, “igniter” It is determined that the unit 60 and the ignition coil 50 are normal.

  When the second predetermined period Tp2 has elapsed from time t22 when the ignition plug 40 is started to be controlled by the “discharge control means” (time t26), the control unit 81 and the abnormality detection unit 93 set the second threshold Th2 at this time. Based on the second current value Id2 corresponding to the secondary current I2 detected by the current detection circuit 91, it is determined whether or not an abnormality has occurred in the energy input unit 70. In the second operation example shown in FIG. 7, since the absolute value of the second current value Id2 is smaller than the absolute value of the second threshold Th2 (0) (S113: NO), the abnormality detection unit 93 is connected to the energy input unit 70. An abnormality detection signal IGf indicating that an abnormality has occurred is output to the control unit 81. Accordingly, the control unit 81 determines that “an abnormality has occurred in the energy input unit 70”, that is, detects an abnormality in the energy input unit 70 (S117).

  When detecting an abnormality of the energy input unit 70 at time t26, the control unit 81 turns off the energy input period signal IGw. As a result, the output of the switching signal SWd from the driver circuit 78 to the switching element 73 is stopped.

  In the present embodiment, the control unit 81 does not detect an abnormality in the igniter unit 60 or the ignition coil 50 as in the second operation example, and detects only an abnormality in the energy input unit 70, so that the air-fuel ratio in the combustion chamber 28 is The throttle valve 2 and the fuel injection valve 4 are controlled so as to be below a predetermined value that can be ignited by normal ignition, that is, to become stoichiometric or rich. For this reason, the air-fuel mixture in the combustion chamber 28 is in a state where it is easily ignited (ignition), and even if it is impossible to input electric energy to the ignition coil 50 by the energy input unit 70, the air-fuel mixture is generated by the “discharge control means”. Can be continuously ignited. As a result, the vehicle can be evacuated. When the control unit 81 receives the abnormality detection signal IGf indicating that “the abnormality has occurred in the energy input unit 70” from the abnormality detection unit 93, for example, the control unit 81 stores the abnormality as diag information and It is possible to notify the driver that "the abnormality has occurred in the energy input unit 70 of the ignition device 11" by turning on a notification lamp or generating a notification sound on the display unit of the driver's seat.

FIG. 8 shows a third operation example (third operation example). The second operation example is an operation example when abnormality occurs in the igniter unit 60 or the ignition coil 50 and the energy input unit 70.
Until time t31-32, since it is the same as time t11-12 of a 1st operation example, description is abbreviate | omitted.

  When the control unit 81 determines that it is time to ignite the air-fuel mixture at time t32 (S103: YES), the ignition signal IGt is turned off (S104). However, in the third operation example, an abnormality has occurred in the igniter unit 60 or the ignition coil 50, so that the absolute value of the secondary voltage V2 remains 0 after time t32. Therefore, the spark plug 40 does not discharge. Therefore, the air-fuel mixture in the combustion chamber 28 is not ignited (not ignited). Further, the absolute value of the secondary current I2 also remains zero.

  When the control unit 81 turns on the energy input period signal IGw at time t33 (S109), the driver circuit 78 of the energy input unit 70 outputs the switching signal SWd that changes to on or off to the switching element 73. However, in the third operation example, since there is also an abnormality in the energy input unit 70, the input of electric energy from the energy input unit 70 to the ignition coil 50 is not started. Therefore, after time t33, the absolute value of the secondary voltage V2 and the absolute value of the secondary current I2 remain zero.

  When the first predetermined period Tp1 has elapsed from time t32 when the ignition plug 40 is started to be controlled by the “discharge control means” (time t34), the control unit 81 and the abnormality detection unit 93 are set to the first threshold value Th1. Based on the first current value Id1 corresponding to the secondary current I2 detected by the current detection circuit 91, it is determined whether or not an abnormality has occurred in the igniter unit 60 or the ignition coil 50. In the third operation example shown in FIG. 8, since the absolute value of the first current value Id1 is smaller than the absolute value of the first threshold value Th1 (0) (S123: NO), the abnormality detection unit 93 is the igniter unit 60 or ignition. An abnormality detection signal IGf indicating that an abnormality has occurred in the coil 50 is output to the control unit 81. Thereby, the control unit 81 determines that “an abnormality has occurred in the igniter unit 60 or the ignition coil 50”, that is, detects an abnormality in the igniter unit 60 or the ignition coil 50 (S125).

  When the second predetermined period Tp2 has elapsed from time t32 when the ignition plug 40 is started to be controlled by the “discharge control means” (time t35), the control unit 81 and the abnormality detection unit 93 set the second threshold Th2 at this time. Based on the second current value Id2 corresponding to the secondary current I2 detected by the current detection circuit 91, it is determined whether or not an abnormality has occurred in the energy input unit 70. In the third operation example shown in FIG. 8, since the absolute value of the second current value Id2 is smaller than the absolute value of the second threshold value Th2 (0) (S113: NO), the abnormality detection unit 93 is connected to the energy input unit 70. An abnormality detection signal IGf indicating that an abnormality has occurred is output to the control unit 81. Accordingly, the control unit 81 determines that “an abnormality has occurred in the energy input unit 70”, that is, detects an abnormality in the energy input unit 70 (S117).

  When detecting an abnormality in the energy input unit 70 at time t35, the control unit 81 turns off the energy input period signal IGw. As a result, the output of the switching signal SWd from the driver circuit 78 to the switching element 73 is stopped.

  In the present embodiment, when the control unit 81 detects an abnormality in the igniter unit 60 or the ignition coil 50 as in the third operation example, the control unit 81 supplies the combustion chamber 28 to which the igniter unit 60 or the ignition coil 50 that detected the abnormality corresponds. The fuel injection valve 4 is controlled to cut off the fuel supply. As a result, the vehicle can be evacuated while reducing (reducing) the number of cylinders 21 used to operate the engine 20. When the control unit 81 receives an abnormality detection signal IGf indicating that an abnormality has occurred in the igniter unit 60 or the ignition coil 50 from the abnormality detection unit 93, for example, the control unit 81 stores the abnormality as diag information. The driver can be informed that "the igniter section 60 of the ignition device 11 or the ignition coil 50 is abnormal" by turning on a notification lamp on the display section of the vehicle driver's seat or generating a notification sound. It is.

As described above, (1) In the present embodiment, the control unit 81 has “discharge control means” and “energy input control means”, and can control ignition of the air-fuel mixture in the combustion chamber 28.
The “discharge control means” generates a high voltage in the secondary coil 52 by controlling the igniter 60 so as to cut off the flow of current from the primary coil 51 to the ground side, so that the spark plug 40 is discharged. 40 is controlled. Thereby, the spark plug 40 is discharged, and the air-fuel mixture can be ignited.

The “energy input control unit” controls the energy input unit 70 to input electric energy to the ignition coil 50 after the control of the spark plug 40 by the “discharge control unit” is started. Thereby, the discharge state of the spark plug 40 caused by the control of the “discharge control means” can be maintained. Therefore, the ignitability of the air-fuel mixture can be improved.
The current detection circuit 91 can detect the current flowing through the secondary coil 52.

  The control unit 81 and the abnormality detection unit 93 (“abnormality detection unit”) can detect an abnormality of the ignition device 11 based on a current value that is a value corresponding to the current detected by the current detection circuit 91.

  In the present embodiment, the control unit 81 and the abnormality detection unit 93 are configured to detect the first threshold value when the first predetermined period Tp1 that is the first predetermined period has elapsed after the start of the control of the spark plug 40 by the “discharge control means”. , And an abnormality in the igniter unit 60 or the ignition coil 50 is detected based on the first threshold value Th1 and the first current value Id1 corresponding to the current (secondary current I2) detected by the current detection circuit 91 at this time. Is possible.

  As described above, in this embodiment, the control unit 81 and the abnormality detection unit 93 detect the current value (first current value Id1) and the threshold value (first threshold value Th1) detected after the start of control of the spark plug 40 by the “discharge control unit”. ) And the abnormality of the igniter 60 or the ignition coil 50 can be detected. Thereby, abnormality of the ignition device 11 can be detected with a simple configuration.

  (2) In the present embodiment, the control unit 81 and the abnormality detection unit 93 perform the second predetermined period longer than the first predetermined period Tp1 after starting the control of the spark plug 40 by the “discharge control means”. Based on the second threshold value Th2 that is the second threshold value when the predetermined period Tp2 has elapsed and the second current value Id2 that is a value corresponding to the current (secondary current I2) detected by the current detection circuit 91 at this time. The abnormality of the energy input unit 70 can be detected. In this configuration, the current value (first current value Id1, second current value Id2) detected by the time difference after the start of control of the spark plug 40 by the "discharge control means" by the control unit 81 and the abnormality detection unit 93 and the two threshold values Based on (the first threshold value Th1 and the second threshold value Th2), the abnormality of the igniter unit 60 or the ignition coil 40 or the abnormality of the energy input unit 70 can be distinguished and detected. Thereby, it is possible to distinguish and detect abnormality of each part (igniter part 60, ignition coil 40 or energy input part 70) constituting the ignition device 11 with a simple configuration. Therefore, the operation of the engine 20 can be switched according to the part where the abnormality is detected.

  (3) In the present embodiment, the energy input unit 70 inputs electric energy to the ignition coil 50 from the ground side of the primary coil 51. The present embodiment shows an example of the configuration of the ignition device 11 (energy input unit 70). In the present embodiment, the ignition device 11 includes one ignition coil 50 for one ignition plug 40. The energy input unit 70 continuously supplies electric energy to the ignition coil 50 from the ground side of the primary coil 51, thereby maintaining the discharge state generated in the spark plug 40 for a predetermined period (energy input period). it can.

  (7) In the present embodiment, the “energy input control means” controls the energy input unit 70 so that a current corresponding to the current target value IGa, which is a predetermined current value, flows through the secondary coil 52. Thus, during the period when the energy input unit 70 supplies electric energy to the ignition coil 50, the secondary current I2 that substantially corresponds to the current target value IGa flows through the secondary coil 52. As a result, the discharge state generated by the spark plug 40 can be stably maintained for a predetermined period (energy input period).

  (10) In the present embodiment, the control unit 81 can control the throttle valve 2 and the fuel injection valve 4. Here, the throttle valve 2 can change the amount of intake air supplied to the combustion chamber 28. The fuel injection valve 4 can change the amount of fuel supplied to the combustion chamber 28.

  The control unit 81 controls the throttle valve 2 and the fuel injection valve 4 so that the air-fuel ratio in the combustion chamber 28 becomes a predetermined value or less when the abnormality detection unit 93 detects only the abnormality of the energy input unit 70. For this reason, the air-fuel mixture in the combustion chamber 28 is in a state where it is easily ignited (ignited), and even if it is impossible to input electric energy to the ignition coil 50 by the energy input unit 70, “discharge control means” (“normally” The ignition of the air-fuel mixture can be continued by the ignition control means "). As a result, the vehicle can be evacuated.

  The control unit 81 controls the fuel injection valve 4 to shut off the supply of fuel to the combustion chamber 28 when the abnormality detection unit 93 detects an abnormality in the igniter unit 60 or the ignition coil 50. As a result, the vehicle can be evacuated while reducing (reducing) the number of cylinders 21 used to operate the engine 20.

  In this way, the operation of the engine 20 is switched according to the part (igniter unit 60 or ignition coil 50 and energy input unit 70) where the abnormality of the ignition device 11 is detected, and the deterioration of fuel consumption, emission and drivability is minimized. The vehicle can be retreated while restrained to the limit.

(Second Embodiment)
An ignition device 11 according to a second embodiment of the present invention will be described with reference to FIG. The second embodiment differs from the first embodiment in how to set the current target value and the second threshold value.

  In the second embodiment, the control unit 81 determines the operating state of the engine 20 based on, for example, the rotational speed of the engine 20, the intake pressure, the fuel injection amount from the fuel injection valve 4, the air-fuel ratio, and the like. The current target value IGa is changed according to the operating state. Specifically, for example, when the control unit 81 determines that the discharge state of the spark plug 40 is easily maintained in the combustion chamber 28 with respect to the operating state of the engine 20, the current target value IGa is less than or equal to a predetermined value. Change to On the other hand, when it is determined that it is difficult to maintain the discharge state of the spark plug 40 in the combustion chamber 28, the target current value IGa is changed to a predetermined value or more. As a result, the value of the secondary current I <b> 2 that flows through the secondary coil 52 when the energy input unit 70 supplies electric energy to the ignition coil 50 changes according to the operating state of the engine 20.

  In addition, the abnormality detection unit 93 changes the second threshold Th2 based on the current target value IGa changed by the control unit 81. Specifically, for example, when the current target value IGa is changed to be small, the abnormality detection unit 93 changes the second threshold value Th2 accordingly. On the other hand, when the current target value IGa is significantly changed, the second threshold Th2 is greatly changed accordingly. Note that the second threshold Th2 changed by the abnormality detection unit 93 can be larger than the first threshold Th1 and smaller than the current target value IGa.

As shown in FIG. 9A, when the control unit 81 determines that the discharge state of the spark plug 40 is not easily maintained in the combustion chamber 28 and is not difficult to maintain in the combustion chamber 28, The current target value IGa and the second threshold value Th2 remain at predetermined values, respectively.
On the other hand, as shown in FIG. 9B, when it is determined that the control unit 81 is in a state where it is difficult to maintain the discharge state of the spark plug 40 in the combustion chamber 28 with respect to the operating state of the engine 20, the current target value IGa and The second threshold Th2 is changed in a direction in which each absolute value increases.

  As described above, (8) In the present embodiment, the control unit 81 changes the current target value IGa according to the operating state of the engine 20. For example, when it is determined that the discharge state of the spark plug 40 is easily maintained in the combustion chamber 28 with respect to the operation state of the engine 20, the control unit 81 changes the target current value IGa to be equal to or less than a predetermined value. When it is determined in the combustion chamber 28 that it is difficult to maintain the discharge state of the spark plug 40, the target current value IGa is changed to a predetermined value or more. As a result, the value of the secondary current I <b> 2 that flows through the secondary coil 52 when the energy input unit 70 supplies electric energy to the ignition coil 50 changes according to the operating state of the engine 20. As a result, regarding the operating state of the engine 20, when it is easy to maintain the discharge state of the spark plug 40 in the combustion chamber 28, energy saving is achieved by reducing the electrical energy input to the ignition coil 50. When it is difficult to maintain the discharge state of the spark plug 40, the spark plug 40 can be reliably discharged by increasing the electric energy supplied to the ignition coil 50.

  (9) In the present embodiment, the abnormality detection unit 93 changes the second threshold Th <b> 2 based on the current target value IGa changed by the control unit 81. For example, when the current target value IGa is changed to a small value, the abnormality detection unit 93 changes the second threshold value Th2 to a small value accordingly. Change a lot. Thereby, abnormality of the energy input part 70 is detectable according to the electric current target value IGa changed. Therefore, even when the current target value IGa is changed, the abnormality of the energy input unit 70 can be detected with high accuracy.

(Other embodiments)
(4) In another embodiment of the present invention, the control unit 81 (abnormality detection unit 93) sets the first threshold value Th1 and the second threshold value Th2 based on, for example, a map of the load of the engine 20 and the rotational speed. It is good as well. In this case, the abnormality of each part of the ignition device 11 can be detected with high accuracy based on the load and the rotational speed of the engine 20.

  Further, (5) In another embodiment of the present invention, the abnormality detection unit 93 determines that the igniter unit 60 or the abnormality detection unit 93 is in a state where the absolute value of the first current value Id1 is smaller than the absolute value of the first threshold Th1 for a predetermined period. An abnormality in the ignition coil 50 may be detected. In this case, the abnormality of the igniter 60 or the ignition coil 50 can be detected with higher accuracy.

  (6) In another embodiment of the present invention, the abnormality detection unit 93 determines that the energy input unit 70 is in a state where the absolute value of the second current value Id2 is smaller than the absolute value of the second threshold Th2 for a predetermined period. It is good also as detecting abnormality of. In this case, the abnormality of the energy input unit 70 can be detected with higher accuracy.

  In the above-described embodiment, the abnormality detection unit detects an abnormality of the igniter unit or the ignition coil based on the first current value and the first threshold value, and the energy input unit detects the abnormality of the energy input unit based on the second current value and the second threshold value. An example of detecting anomalies was given. On the other hand, in another embodiment of the present invention, the abnormality detection means does not detect the abnormality of the energy input unit, and detects only the abnormality of the igniter unit or the ignition coil based on the first current value and the first threshold value. It is good as well.

  Further, in the above-described embodiment, an example in which one ignition coil is provided for one ignition plug and the control device is applied to an ignition device in which the energy input unit inputs electric energy to the ignition coil from the ground side of the primary coil. Indicated. On the other hand, in another embodiment of the present invention, for example, a plurality of ignition coils are provided for one ignition plug, and electric energy is continuously input from the energy input unit to the plurality of ignition coils after discharge control of the ignition plug. Accordingly, the control device can be applied to an ignition device capable of maintaining the discharge state of the ignition plug.

  Further, the energy input unit may be any unit as long as it can input electric energy capable of continuing the ignition state (maintaining the discharge state of the spark plug). The “DCO method” disclosed in Japanese Patent Application Laid-Open No. 2012-167665 may be used. For example, when the DCO method is adopted, the part of the two ignition coils that starts the main discharge is regarded as a “normal coil”, and the electric energy is supplied to the ignition coil that can maintain the discharge state after the main discharge. May be regarded as an “energy input part”.

In the above-described embodiment, the “energy input control unit” feeds back the value of the secondary current I2, so that the current corresponding to the current target value IGa that is a predetermined current value flows through the secondary coil 52. The example which controls the energy input part 70 was shown. On the other hand, in another embodiment of the present invention, the “energy input control means” does not feed back the value of the secondary current I2, and the energy input so that the current corresponding to the current target value IGa flows through the secondary coil 52. The unit 70 may not be controlled.
In another embodiment of the present invention, when the control unit detects an abnormality in the igniter unit, the ignition coil, or the energy input unit, the control unit only notifies the detected abnormality without controlling the throttle valve or the fuel injection valve. But you can.

  Further, in another embodiment of the present invention, the energy input unit 70 may be configured without the capacitor 76. Even if the capacitor 76 is not provided, electric energy can be supplied to the ignition coil by appropriately switching the switching elements 72 and 73.

  In another embodiment of the present invention, the energy input unit may be, for example, a part that can input electric energy from a high-voltage power supply different from the power supply 12 to the ignition coil. In this case, compared with the above-mentioned embodiment, the number of members constituting the energy input unit can be reduced.

In another embodiment of the present invention, the switching element 61 of the igniter unit 60 is not limited to the IGBT, and may be configured by other semiconductor switching elements such as a MOSFET and a transistor. Further, since the MOSFET generally has a parasitic diode, the diode 62 can be omitted when the switching element 61 is configured by a MOSFET.
In another embodiment of the present invention, the switching elements 72 and 73 of the energy input unit 70 are not limited to MOSFETs, and may be configured by other semiconductor switching elements such as IGBTs and transistors.

Moreover, in the above-mentioned embodiment, the example which accommodates the igniter part 60 in the housing | casing of the ignition circuit unit 13 was shown. On the other hand, in another embodiment of the present invention, the igniter unit 60 may be provided in the vicinity of the ignition coil 50 without being housed in the casing of the ignition circuit unit 13.
In the above-described embodiment, the example in which the current detection circuit 91 and the abnormality detection unit 93 are housed in the casing of the ignition circuit unit 13 has been described. On the other hand, in another embodiment of the present invention, at least one of the current detection circuit 91 or the abnormality detection unit 93 may be housed in the casing of the ECU 80. Further, the control unit 81 of the ECU 80 may include at least one of the current detection circuit 91 or the abnormality detection unit 93.
The control device of the present invention can also be applied to an ignition device for an engine system that does not include an exhaust gas recirculation (EGR) system.

In the above-described embodiment, an example in which a negative secondary current flows through the secondary coil of the ignition coil when the spark plug is discharged has been described. On the other hand, in another embodiment of the present invention, a secondary current in the positive direction may flow through the secondary coil of the ignition coil when the spark plug is discharged.
Moreover, in the above-mentioned embodiment, the energy injection | throwing-in part showed the example which inputs electric energy with respect to an ignition coil so that the secondary current of a negative direction may be superimposed. On the other hand, in another embodiment of the present invention, the energy input unit may be configured to input electric energy to the ignition coil such that a secondary current in the positive direction is superimposed.

Further, the control device of the present invention is not limited to a four-cylinder internal combustion engine, and can be applied to an ignition device for an internal combustion engine having a number of cylinders other than four.
The control device of the present invention is not limited to a premixed combustion type internal combustion engine, but can also be applied to an ignition device for a direct injection type internal combustion engine.
Thus, the present invention is not limited to the above-described embodiment, and can be implemented in various forms without departing from the gist thereof.

DESCRIPTION OF SYMBOLS 10 ... Control apparatus 11 ... Ignition apparatus 12 ... Power supply 20 ... Engine (internal combustion engine)
28 ... Combustion chamber 40 ... Spark plug 50 ... Ignition coil 51 ... Primary coil 52 ... Secondary coil 60 ... Igniter part 70 ... Energy input part 81 ... Control part (Discharge control means, energy input control means, abnormality detection means)
91 ・ ・ ・ Current detection circuit (current detection means)
93 ... Abnormality detection unit (abnormality detection means)

Claims (11)

An ignition plug (40) provided in the combustion chamber (28) of the internal combustion engine (20) and capable of igniting an air-fuel mixture in the combustion chamber by discharging;
An ignition coil (50) having a primary coil (51) having one end connected to the power source (12) and the other end connected to the ground side, and a secondary coil (52) having one end connected to the spark plug; ,
An igniter section (60) provided to allow or block the flow of current from the primary coil to the ground side;
And a control device (10) capable of controlling an ignition device (11) including an energy input unit (70) capable of supplying electric energy to the ignition coil, and controlling ignition of an air-fuel mixture in the combustion chamber. ,
Discharge control for controlling the ignition plug to discharge the spark plug by causing the secondary coil to generate a high voltage by controlling the igniter unit so as to cut off the flow of current from the primary coil to the ground side. Means (81), and
After starting the discharge control of the spark plug by the discharge control means, it has energy input control means (81) for controlling the energy input unit to input electric energy to the ignition coil,
A control unit (81) capable of controlling ignition of the air-fuel mixture in the combustion chamber;
Current detection means (91) capable of detecting a current flowing through the secondary coil;
An abnormality detection means (81, 93) capable of detecting an abnormality of the ignition device based on a current value corresponding to the current detected by the current detection means,
The abnormality detection means includes
A determination waiting time is provided after starting the discharge control of the spark plug by the discharge control means,
When the first predetermined period (Tp1) which is the first predetermined period as the determination waiting time has elapsed, the first threshold (Th1) which is a first threshold other than 0, and at this time detected by the current detection means When the absolute value of the first current value is smaller than the absolute value of the first threshold value based on the first current value (Id1) that is a value corresponding to the measured current, an abnormality in the igniter unit or the ignition coil is detected. A control device.   The igniter unit is connected to the ground side of the primary coil, allows a current flow from the ground side to the primary coil side, and blocks a current flow from the primary coil side to the ground side (62). The control device according to claim 1, comprising: The energy charge unit, the control device according to claim 1 or 2, characterized in that turning on the electric energy to said ignition coil from ground side of the primary coil. The abnormality detection unit detects an abnormality of the igniter unit or the ignition coil when a state where the absolute value of the first current value is smaller than the absolute value of the first threshold value continues for a predetermined period. Item 4. The control device according to any one of Items 1 to 3 . The abnormality detection means includes
After starting control of the spark plug by the discharge control means,
When a second predetermined period (Tp2) that is a second predetermined period longer than the first predetermined period has elapsed, a second threshold (Th2) that is a second threshold and the current detected by the current detection means at this time based on the corresponding second current value is a value between (Id2) to the control device according to any one of claims 1-4, characterized in that for detecting an abnormality of the energy charge unit. 6. The control device according to claim 5 , wherein the abnormality detection unit sets the first threshold value and the second threshold value based on a load and a rotational speed of the internal combustion engine. The abnormality detecting means, when the absolute value of the second current value is smaller than that the absolute value of the second threshold continues for a predetermined time period, according to claim 5 or and detects an abnormality of the energy charge unit 6. The control device according to 6 . The energy charge control means, any of the claims 5-7, wherein the controller controls the energy supplying portion so that current corresponding to a current target value (IGa) is a predetermined current value flows through the secondary coil A control device according to claim 1. The control device according to claim 8 , wherein the control unit changes the target current value according to an operating state of the internal combustion engine. The control device according to claim 9 , wherein the abnormality detection unit changes the second threshold value based on the current target value changed by the control unit. The controller is
A throttle valve (2) capable of changing the amount of intake air supplied to the combustion chamber, and a fuel injection valve (4) capable of changing the amount of fuel supplied to the combustion chamber are controllable;
When detecting only the abnormality of the energy input unit by the abnormality detection means, the throttle valve and the fuel injection valve are controlled so that the air-fuel ratio in the combustion chamber becomes a predetermined value or less,
When detecting an abnormality of the igniter portion or the ignition coil by the abnormality detecting means, any of claims 5 to 10, wherein the controller controls the fuel injection valve to shut off the supply of fuel to the combustion chamber A control device according to claim 1.

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