WO2024018575A1 - Internal combustion engine control device - Google Patents

Internal combustion engine control device Download PDF

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Publication number
WO2024018575A1
WO2024018575A1 PCT/JP2022/028271 JP2022028271W WO2024018575A1 WO 2024018575 A1 WO2024018575 A1 WO 2024018575A1 JP 2022028271 W JP2022028271 W JP 2022028271W WO 2024018575 A1 WO2024018575 A1 WO 2024018575A1
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WO
WIPO (PCT)
Prior art keywords
coil
temperature
ignition
internal combustion
control device
Prior art date
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PCT/JP2022/028271
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French (fr)
Japanese (ja)
Inventor
一浩 押領司
修 向原
Original Assignee
日立Astemo株式会社
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Publication date
Application filed by 日立Astemo株式会社 filed Critical 日立Astemo株式会社
Priority to PCT/JP2022/028271 priority Critical patent/WO2024018575A1/en
Publication of WO2024018575A1 publication Critical patent/WO2024018575A1/en

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    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
    • F02P—IGNITION, OTHER THAN COMPRESSION IGNITION, FOR INTERNAL-COMBUSTION ENGINES; TESTING OF IGNITION TIMING IN COMPRESSION-IGNITION ENGINES
    • F02P3/00—Other installations
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
    • F02P—IGNITION, OTHER THAN COMPRESSION IGNITION, FOR INTERNAL-COMBUSTION ENGINES; TESTING OF IGNITION TIMING IN COMPRESSION-IGNITION ENGINES
    • F02P3/00—Other installations
    • F02P3/02—Other installations having inductive energy storage, e.g. arrangements of induction coils
    • F02P3/04—Layout of circuits
    • F02P3/05—Layout of circuits for control of the magnitude of the current in the ignition coil
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
    • F02P—IGNITION, OTHER THAN COMPRESSION IGNITION, FOR INTERNAL-COMBUSTION ENGINES; TESTING OF IGNITION TIMING IN COMPRESSION-IGNITION ENGINES
    • F02P5/00—Advancing or retarding ignition; Control therefor
    • F02P5/04—Advancing or retarding ignition; Control therefor automatically, as a function of the working conditions of the engine or vehicle or of the atmospheric conditions
    • F02P5/145—Advancing or retarding ignition; Control therefor automatically, as a function of the working conditions of the engine or vehicle or of the atmospheric conditions using electrical means
    • F02P5/15—Digital data processing

Definitions

  • the present invention relates to a control device for an internal combustion engine.
  • Patent Document 1 As a technique for increasing the energy supplied to a spark plug.
  • a main primary coil and a sub-primary coil are arranged on the primary side of an ignition coil that provides energy to a spark plug.
  • the sub-primary coil is energized after the main primary coil is de-energized.
  • the amount of current applied to the ignition coil is increased too much in order to increase the amount of energy supplied to the spark plug, the temperature of the ignition coil will rise excessively due to the heat generated by the ignition coil, which may cause the ignition coil to malfunction. Therefore, it is necessary to set an upper limit value for the amount of current applied to the ignition coil so that the ignition coil does not exceed the upper limit temperature even when the ignition coil is used in the harshest usage environment.
  • the upper limit value of the amount of current applied to the ignition coil is set with a margin. If this margin is too large, the amount of current supplied to the ignition coil will be greatly restricted, and the amount of energy supplied to the spark plug will also be greatly restricted.
  • the present invention has been made in view of the above, and an object of the present invention is to provide a control device for an internal combustion engine that can achieve both stable combustion of an air-fuel mixture and prevention of failures due to heat generation of an ignition coil. .
  • the present invention provides an internal combustion engine control device that includes an ignition plug and an ignition coil, and estimates a coil temperature that is the temperature inside or around the ignition coil. and an ignition control unit that controls the current supplied to the spark plug by controlling energization of the ignition coil, and the ignition coil is configured to an increasing mechanism that increases the current, and the ignition control unit controls the increasing amount such that the higher the estimated coil temperature, the smaller the increasing amount of the current by the increasing mechanism. It is characterized by
  • FIG. 1 is a diagram showing a schematic configuration of an internal combustion engine system including a control device according to the present embodiment.
  • 2 is a diagram showing a schematic configuration of an ignition coil and an ignition coil energization circuit shown in FIG. 1.
  • FIG. FIG. 3 is a diagram illustrating the operation of an ignition coil and an ignition coil energization circuit.
  • 1 is a block diagram showing a functional configuration of a control device according to a first embodiment;
  • FIG. 5 is a block diagram showing a detailed configuration of the temperature estimation section shown in FIG. 4.
  • FIG. Figure 6(a) is a diagram illustrating a map showing the relationship between the energization amount of the primary coil, the dilution of the mixture, and the rotational speed of the internal combustion engine, and FIG.
  • FIG. 6(b) is a diagram illustrating the relationship between the energization amount of the tertiary coil and the mixture
  • FIG. 3 is a diagram illustrating a map showing the relationship between the degree of dilution and the rotational speed of an internal combustion engine.
  • FIG. 7(a) is a diagram illustrating an example of controlling the energization amount of the tertiary coil according to the coil temperature
  • FIG. 7(b) is an example of controlling the energization amount of each of the primary coil and the tertiary coil according to the coil temperature.
  • FIG. 3 is a block diagram showing the functional configuration of a control device according to a second embodiment.
  • FIG. 9(a) is a diagram illustrating the relationship between the length of the return signal and the coil temperature
  • FIG. 9(b) is a diagram illustrating the length of the return signal.
  • FIG. 3 is a diagram illustrating a map showing the relationship between the upper limit value of the current (energy) generated by a secondary coil and the target value of the EGR rate and/or the target value of the air-fuel ratio of the air-fuel mixture.
  • FIG. 3 is a diagram illustrating a temperature characteristic diagnosis section.
  • FIGS. 1 to 7 A control device 200 for an internal combustion engine 100 according to a first embodiment will be described using FIGS. 1 to 7.
  • FIG. 1 is a diagram showing a schematic configuration of an internal combustion engine system 1 including a control device 200 of this embodiment.
  • the internal combustion engine 100 is controlled by an engine control unit (ECU) 200 and an accelerator opening sensor 140 that detects the accelerator opening.
  • the internal combustion engine 100 includes a piston 101, an intake valve 102, and an exhaust valve 103 in a cylinder.
  • the internal combustion engine 100 can be an internal combustion engine having a plurality of cylinders, for example, four cylinders, but FIG. 1 representatively shows only one cylinder among the plurality of cylinders. .
  • a crankshaft (not shown) is connected to the piston 101.
  • the crankshaft is composed of a main shaft and a subshaft.
  • the subshaft is connected to the piston 101 via a connecting rod.
  • the crankshaft may include a variable compression ratio mechanism that changes the distance between the main shaft and the subshaft or the length of the connecting rod. By including the variable compression ratio mechanism, the internal combustion engine 100 can change the stroke amount of the piston 101, and can make the pressure within the combustion chamber R1 variable.
  • a spark plug 105 and an ignition coil 150 are provided in the cylinder head. Further, the cylinder head is provided with a fuel injection valve 107 that directly injects fuel into the combustion chamber R1 within the cylinder. Although not shown, the water jacket of the cylinder is equipped with a water temperature sensor that detects the temperature of cooling water.
  • an intake pipe 110 is provided upstream of the intake valve 102 to introduce air to be taken into the internal combustion engine 100.
  • An exhaust pipe 111 is provided on the downstream side of the exhaust valve 103 to discharge exhaust gas discharged from the cylinder to the outside.
  • the intake pipe 110 includes an intercooler 112 that cools the intake gas, a throttle valve 113 that adjusts the amount of intake air according to the accelerator opening, a surge tank 114 that adjusts the flow of the intake gas, and a portion of the intake pipe 110.
  • a tumble control valve (TCV) 115 is provided which narrows the intake gas flow and causes turbulence (tumble) in the intake gas flow.
  • the exhaust pipe 111 is communicated with an exhaust passage 121.
  • the exhaust passage 121 is provided with a three-way catalyst 123, an air-fuel ratio sensor 124, and a turbine 125b.
  • the three-way catalyst 123 is for purifying exhaust gas.
  • the air-fuel ratio sensor 124 is a sensor that detects the air-fuel ratio of exhaust gas.
  • the turbine 125b uses the energy of the exhaust gas to generate driving force for driving the compressor 125a.
  • the exhaust passage 121 branches into an EGR pipe 126 on the downstream side of the three-way catalyst 123.
  • the EGR pipe 126 is a pipe for recirculating exhaust gas to the intake side as EGR gas.
  • the EGR pipe 126 is connected to an intake passage 130 that communicates with the intake pipe 110.
  • the EGR pipe 126 is provided with an EGR cooler 127 that cools the EGR gas, an EGR valve 128 that adjusts the amount of EGR gas, and a pressure sensor 133 that detects the pressure before and after the EGR valve 128.
  • a three-way catalyst 129 different from the three-way catalyst 123 is provided further downstream of the branch point of the exhaust passage 121 with the EGR pipe 126.
  • the intake pipe 110 is communicated with an intake passage 130 on the compressor 125a side.
  • the intake passage 130 is provided with an air flow sensor 131 that measures the air flow rate and a pressure adjustment valve 132 that adjusts the intake pressure.
  • the intake pipe 110 is provided with an oxygen concentration sensor 134 that detects the oxygen concentration of intake gas (a gas obtained by mixing intake air supplied from the intake passage 130 and EGR gas).
  • the intake gas flows into the combustion chamber R1 through the intercooler 112, the intake pipe 110, the surge tank 114, the tumble valve 115, and the intake valve 102.
  • Fuel is injected from the fuel injection valve 107 into the intake gas that has flowed into the combustion chamber R1 to form an air-fuel mixture.
  • the air-fuel mixture is ignited and combusted by a spark generated from the spark plug 105 at a predetermined ignition timing.
  • the internal combustion engine 100 generates power as the combustion pressure generated by combustion of the air-fuel mixture pushes down the piston 101.
  • the exhaust gas after combustion is sent to the three-way catalyst 123 via the exhaust valve 103, the exhaust pipe 111, and the turbine 125b, and NOx, CO, and HC components are purified within the three-way catalyst 123. Thereafter, the exhaust gas is sent to the three-way catalyst 129 through the exhaust passage 121, purified again within the three-way catalyst 129, and discharged to the outside.
  • a part of the exhaust gas is introduced into the intake passage 130 as EGR gas through the EGR pipe 126, the EGR cooler 127, and the EGR valve 128.
  • the EGR gas introduced into the intake passage 130 merges with the intake air to form intake gas in which the intake air and EGR gas are mixed.
  • the intake gas passes through the intake pipe 110 and the like and reaches the combustion chamber R1.
  • the control device 200 is configured by an electronic control unit including a processor such as a CPU, and a storage device such as a ROM and a RAM.
  • the control device 200 realizes the functions of the control device 200 by the CPU executing a program stored in the ROM. Specifically, the control device 200 calculates the required torque based on the detection signal of the accelerator opening sensor 140 and various sensor signals.
  • the control device 200 controls the opening degree of the pressure regulating valve 132, the opening degree of the throttle valve 113, and the opening degree of the fuel injection valve 107 based on the operating state of the internal combustion engine 100 and the operating conditions of the internal combustion engine 100 obtained from detection signals of various sensors.
  • the main operating quantities of the internal combustion engine 100 such as the injection pulse period, the ignition timing of the spark plug 105, the opening/closing timing of the intake valve 102 and the exhaust valve 103, and the opening degree of the EGR valve 128, are calculated.
  • FIG. 2 is a diagram showing a schematic configuration of the ignition coil 150 and the ignition coil energization circuit 160 shown in FIG. 1.
  • FIG. 3 is a diagram illustrating the operation of the ignition coil 150 and the ignition coil energization circuit 160.
  • the ignition coil 150 constitutes a transformer that supplies the ignition plug 105 with the current (energy) necessary for the ignition plug 105 to ignite the air-fuel mixture and combust the air-fuel mixture.
  • the ignition coil 150 includes a primary coil 151 placed on the primary side of the transformer, a secondary coil 152 placed on the secondary side of the transformer and connected to the spark plug 105, and a secondary coil 152 placed on the primary side of the transformer. It has a tertiary coil 153 arranged.
  • the primary coil 151, the secondary coil 152, and the tertiary coil 153 are wound around the same core.
  • the number of turns of the secondary coil 152 is greater than the total number of turns of the primary coil 151 and the tertiary coil 153.
  • the ignition coil energization circuit 160 includes a primary coil energization circuit 161, a tertiary coil energization circuit 162, and a tertiary current monitoring circuit 163.
  • the primary coil energization circuit 161 is a circuit that energizes the primary coil 151 based on a primary coil energization signal from the control device 200.
  • the tertiary coil energization circuit 162 is a circuit that energizes the tertiary coil 153 based on a tertiary coil energization signal from the control device 200.
  • Each of the primary coil energizing circuit 161 and the tertiary coil energizing circuit 162 includes, for example, an igniter.
  • the tertiary current monitoring circuit 163 monitors the current flowing through the tertiary coil 153 (also referred to as "tertiary current”). Specifically, the tertiary current monitoring circuit 163 detects the current flowing through the tertiary coil 153 and also detects a return signal from the tertiary coil 153, and outputs it to the control device 200.
  • the return signal is a signal output from the ignition coil 150 side to the control device 200 side in response to energization of the ignition coil 150.
  • the return signal of this embodiment is output when the energization of the tertiary coil 153 stops, particularly when the energization stops abnormally. Therefore, the return signal of this embodiment can be said to be a signal indicating the diagnosis result of the tertiary coil 153 (also referred to as a "diagnosis signal").
  • the control device 200 When the spark plug 105 is ignited, the control device 200 outputs a primary coil energization signal to the primary coil energization circuit 161 to energize the primary coil 151.
  • the primary coil energization signal may be a pulse signal that exhibits a high level when the primary coil 151 is energized and a low level when the primary coil 151 is not energized.
  • the energization period of the primary coil 151 is set according to the amount of energization of the primary coil 151, and is adapted to the dwell angle.
  • the primary coil 151 When the primary coil 151 is energized (when energization is started and stopped), a current is generated in the secondary coil 152 by electromagnetic induction, and the generated current is supplied to the spark plug 105. As shown in the lower part of FIG. 3, the current generated by the secondary coil 152 becomes a large current corresponding to the energization period of the primary coil 151, and decreases as time passes.
  • energizing the primary coil 151 alone may not be enough to supply the amount of energy to the spark plug 105 necessary for stable combustion of the air-fuel mixture. There may be a shortage.
  • the control device 200 while supplying current to the spark plug 105 by energizing the primary coil 151, the control device 200 outputs a tertiary coil energization signal to the tertiary coil energization circuit 162 to energize the tertiary coil 153.
  • the tertiary coil energization signal may be a pulse signal that exhibits a high level during the energization period of the tertiary coil 153 and a low level during the non-energization period of the tertiary coil 153, as shown in the middle part of FIG.
  • the energization period of the tertiary coil 153 is set according to the amount of energization of the tertiary coil 153.
  • the amount and timing of energization of the tertiary coil 153 are set according to the amount and timing of the shortage of energy supplied to the spark plug 105.
  • the energization period of the tertiary coil 153 is also referred to as an overlapping period because the energization of the primary coil 151 and the energization of the tertiary coil 153 overlap.
  • the tertiary coil 153 When the tertiary coil 153 is energized while the primary coil 151 is supplying current to the ignition plug 105, a current is generated in the secondary coil 152 by electromagnetic induction, and the generated current is supplied to the ignition plug 105. . As shown in the lower part of FIG. 3, the current generated by the secondary coil 152 is such that a current corresponding to the energization of the tertiary coil 153 is superimposed on a current corresponding to the energization of the primary coil 151. As a result, the current supplied to the spark plug 105 increases.
  • the ignition coil 150 of this embodiment has the tertiary coil 153 as an increasing mechanism that increases the current while it is being supplied to the spark plug 105.
  • this increasing mechanism is not limited to the tertiary coil 153.
  • FIG. 4 is a block diagram showing the functional configuration of the control device 200 of the first embodiment.
  • FIG. 5 is a block diagram showing the detailed configuration of temperature estimating section 210 shown in FIG. 4.
  • FIG. 6A is a diagram illustrating a map showing the relationship between the amount of current applied to the primary coil 151, the degree of dilution of the air-fuel mixture, and the rotational speed of the internal combustion engine 100.
  • FIG. 6B is a diagram illustrating a map showing the relationship between the amount of current applied to the tertiary coil 153, the degree of dilution of the air-fuel mixture, and the rotational speed of the internal combustion engine 100.
  • FIG. 6A is a diagram illustrating a map showing the relationship between the amount of current applied to the primary coil 151, the degree of dilution of the air-fuel mixture, and the rotational speed of the internal combustion engine 100.
  • FIG. 6B is a diagram illustrating a map showing the relationship between the amount of current applied to the tertiary
  • FIG. 7A is a diagram illustrating an example of controlling the amount of current applied to the tertiary coil 153 according to the coil temperature.
  • FIG. 7B is a diagram illustrating an example of controlling the amount of current applied to the primary coil 151 and the tertiary coil 153 according to the coil temperature.
  • the control device 200 includes a temperature estimation section 210 and an ignition control section 220.
  • the temperature estimation unit 210 estimates the coil temperature, which is the temperature inside or around the spark plug 105.
  • the temperature estimation unit 210 estimates the coil temperature based on the operating conditions of the internal combustion engine 100, the cooling water temperature of the internal combustion engine 100, and the amount of current applied to the ignition coil 150.
  • the temperature estimation section 210 includes a heat generation amount calculation section 211, a heat radiation amount calculation section 212, a temperature calculation section 213, and a temperature update section 214.
  • the calorific value calculation unit 211 calculates the calorific value Qc(J) of the ignition coil 150 based on the amount of current applied to the ignition coil 150 and the operating conditions of the internal combustion engine 100. Specifically, as shown in FIG. 5, the calorific value calculation unit 211 stores a calorific value indicating the relationship between the amount of energization of the primary coil 151 and the tertiary coil 153 and the calorific value of the ignition coil 150 per ignition. A quantity map is provided in advance. The calorific value calculation unit 211 uses this calorific value map to specify the calorific value of the ignition coil 150 per ignition from the respective energization amounts of the primary coil 151 and the tertiary coil 153.
  • the calorific value calculation unit 211 calculates the calorific value Qc(J) of the ignition coil 150 using equation (1).
  • Calorific value Qc (J) qc (J/ignition) x ⁇ t x rotation speed (rpm)/120...(1)
  • qc (J/ignition) is the amount of heat generated by the ignition coil 150 per ignition.
  • ⁇ t is the coil temperature calculation interval (s).
  • the temperature update unit 214 updates and stores the previously calculated coil temperature Tc using the coil temperature Tc' currently calculated by the temperature calculation unit 213.
  • the temperature estimation unit 210 can estimate the coil temperature based on the operating conditions of the internal combustion engine 100, the cooling water temperature of the internal combustion engine 100, and the amount of current flowing through the ignition coil 150.
  • control device 200 can grasp the temperature of the ignition coil 150 without adding hardware such as a temperature sensor and a temperature detection circuit. Therefore, the control device 200 can easily prevent failures due to heat generation in the ignition coil 150 while ensuring the amount of energy supplied to the spark plug 105 necessary for stable combustion of the air-fuel mixture.
  • the ignition control unit 220 controls the current supplied to the spark plug 105 by controlling the energization of the ignition coil 150. Specifically, the ignition control unit 220 sets the amount of current applied to the primary coil 151 based on the operating conditions of the internal combustion engine 100 and the dilution level of the air-fuel mixture. For example, as shown in FIG. 6(a), the ignition control unit 220 is provided with a map showing the relationship between the amount of current applied to the primary coil 151, the degree of dilution of the air-fuel mixture, and the rotational speed of the internal combustion engine 100. There is.
  • the ignition control unit 220 sets the energization amount of the primary coil 151 used for the current energization based on the rotation speed of the internal combustion engine 100 and the degree of dilution of the air-fuel mixture, using the map shown in FIG. 6(a). Ignition control section 220 generates a primary coil energization signal according to the set amount of energization of primary coil 151 and outputs it to primary coil energization circuit 161 .
  • the ignition control unit 220 sets the amount of current applied to the tertiary coil 153 based on the operating conditions of the internal combustion engine 100 and the dilution level of the air-fuel mixture. Specifically, as shown in FIG. 6(b), the ignition control unit 220 has a map in advance that shows the relationship between the amount of electricity supplied to the tertiary coil 153, the dilution level of the air-fuel mixture, and the rotational speed of the internal combustion engine 100. It is provided. The ignition control unit 220 uses the map shown in FIG.
  • Ignition control section 220 generates a tertiary coil energization signal according to the set amount of energization of tertiary coil 153 and outputs it to tertiary coil energization circuit 162 .
  • the ignition control unit 220 sets the energization amount of the tertiary coil 153 so that the higher the estimated coil temperature, the smaller the energization amount of the tertiary coil 153, as shown in FIG.
  • the amount of current applied to the secondary coil 153 is controlled. Specifically, the ignition control unit 220 sets the upper limit value of the energization amount of the tertiary coil 153 such that the higher the estimated coil temperature, the smaller the energization amount of the tertiary coil 153. Then, the ignition control unit 220 may set the amount of current applied to the tertiary coil 153 to be equal to or less than this upper limit value.
  • the ignition control unit 220 can limit (reduce) the amount of current applied to the tertiary coil 153 within the range of the amount of current that does not cause the ignition coil 150 to malfunction due to heat generation. Therefore, the control device 200 can prevent failures due to heat generation in the ignition coil 150 while ensuring the amount of energy supplied to the spark plug 105 necessary for stable combustion of the air-fuel mixture.
  • the predetermined temperature may be a temperature (for example, 150° C.) at which the ignition coil 150 will not fail due to heat generation even if the ignition coil 150 is used in the harshest usage environment.
  • the harshest environment in which the ignition coil 150 is used is, for example, an environment where heat is trapped in the engine room, such as after rapid acceleration of a car.
  • the engine room temperature or the cooling water temperature may be, for example, 120°C.
  • control device 200 can reliably prevent failures due to heat generation in the ignition coil 150 while ensuring the amount of energy supplied to the spark plug 105 necessary for stable combustion of the air-fuel mixture.
  • the ignition control unit 220 can control not only the amount of energization of the tertiary coil 153 but also the amount of energization of the primary coil 151 according to the coil temperature. For example, as shown in FIG. 7(b), when the rotational speed of the internal combustion engine 100 is high, a large current is required to be supplied to the spark plug 105, so it is difficult to limit the amount of current flowing through the primary coil 151. Therefore, when the rotational speed of the internal combustion engine 100 is high, the ignition control unit 220 prioritizes and limits (reduces) the amount of energization of the tertiary coil 153 over the amount of energization of the primary coil 151.
  • the ignition control unit 220 prioritizes and limits (reduces) the amount of energization of the primary coil 151 over the amount of energization of the tertiary coil 153.
  • the control device 200 can reliably and efficiently secure the amount of energy supplied to the spark plug 105 necessary for stable combustion of the air-fuel mixture. , failure due to heat generation of the ignition coil 150 can be prevented.
  • the control device 200 of the first embodiment is a control device for the internal combustion engine 100 that includes the spark plug 105 and the ignition coil 150, and estimates the coil temperature, which is the temperature inside or around the ignition coil 150.
  • the ignition control unit 220 includes a temperature estimation unit 210 and an ignition control unit 220 that controls current supplied to the spark plug 105 by controlling energization of the ignition coil 150.
  • the ignition coil 150 has an increasing mechanism that increases the current while supplying the current to the spark plug 105.
  • the ignition control unit 220 controls the amount of increase in current due to the increase mechanism so that the higher the estimated coil temperature is, the smaller the amount of increase in current due to the increase mechanism becomes.
  • control device 200 of the first embodiment can limit (reduce) the amount of increase in current by the increasing mechanism to within the range of the amount of current that does not cause the ignition coil 150 to malfunction due to heat generation. Therefore, the control device 200 of the first embodiment can prevent failure due to heat generation of the ignition coil 150 while ensuring the amount of energy supplied to the spark plug 105 necessary for stable combustion of the air-fuel mixture. Therefore, the control device 200 of the first embodiment can achieve both stable combustion of the air-fuel mixture and prevention of failures due to heat generation of the ignition coil 150.
  • FIGS. 8 to 12 A control device 200 for an internal combustion engine 100 according to a second embodiment will be described using FIGS. 8 to 12.
  • the control device 200 for the internal combustion engine 100 according to the second embodiment descriptions of the same configuration and operation as those in the first embodiment will be omitted.
  • FIG. 8 is a block diagram showing the functional configuration of the control device 200 of the second embodiment.
  • FIG. 9(a) is a diagram illustrating the relationship between the length of the return signal and the coil temperature.
  • FIG. 9(b) is a diagram illustrating the length of the return signal.
  • FIG. 10 is a diagram illustrating a map showing the relationship between the energization amount of the primary coil 151 or the tertiary coil 153 and the current (energy) generated by the secondary coil 152.
  • FIG. 11 is a diagram illustrating a map showing the relationship between the upper limit value of the current (energy) generated by the secondary coil 152 and the target value of the EGR rate and/or the target value of the air-fuel ratio of the air-fuel mixture.
  • FIG. 12 is a diagram illustrating the temperature characteristic diagnosis section 250.
  • the control device 200 of the second embodiment includes a temperature estimation section 210, an ignition control section 220, a generated current estimation section 230, a dilution setting section 240, and a temperature characteristic diagnosis section 250.
  • the ignition control unit 220 of the second embodiment is the same as that of the first embodiment, so a description thereof will be omitted.
  • the temperature estimation unit 210 of the second embodiment estimates the coil temperature based on a return signal output from the ignition coil 150 side to the control device 200 side in response to energization of the ignition coil 150.
  • the return signal is output when the energization of the tertiary coil 153 stops, particularly when the energization stops abnormally.
  • the length of the return signal varies depending on the characteristics of the ignition coil 150 as a component. As shown in FIG. 9(a), the length of the return signal increases as the coil temperature increases.
  • the length of the return signal may be the time width of the return signal itself, or may be the time width of the return signal and the tertiary coil energization signal, as shown in FIG. 9(b). That is, the length of the return signal may be the time from the rise of the tertiary coil energization signal to the fall of the return signal.
  • the temperature estimation unit 210 of the second embodiment is provided with a map showing the relationship between the length of the return signal and the coil temperature in advance.
  • the temperature estimation unit 210 of the second embodiment estimates the coil temperature from the length of the return signal using the map shown in FIG. 9(a).
  • the temperature estimating unit 210 of the second embodiment can estimate the coil temperature in accordance with the temperature characteristics of the ignition coil 150, so that the accuracy of estimating the coil temperature can be improved compared to the first embodiment. Therefore, the control device 200 of the second embodiment can more reliably prevent failures due to heat generation in the ignition coil 150 while ensuring the amount of energy supplied to the spark plug 105 necessary for stable combustion of the air-fuel mixture.
  • the generated current estimation unit 230 estimates the upper limit value of the generated current (energy) of the secondary coil 152 based on the amount of energization of the primary coil 151 and the amount of energization of the tertiary coil 153. Specifically, as shown in FIG. 10, the generated current estimation unit 230 calculates the relationship between the amount of energization of the primary coil 151 and the generated current (energy) of the secondary coil 152, and the energization of the tertiary coil 153. A map showing the relationship between the amount and the current (energy) generated by the secondary coil 152 is provided in advance.
  • the generated current estimating unit 230 specifies the generated current (energy) of the secondary coil 152 from the amount of energization of the primary coil 151 and the tertiary coil 153 using the map shown in FIG.
  • the generated current estimation unit 230 calculates the total value of the current (energy) generated in the secondary coil 152 due to the energization of the primary coil 151 and the current (energy) generated in the secondary coil 152 due to the energization of the tertiary coil 153;
  • the current (energy) generated by the secondary coil 152 is calculated from the conversion efficiency.
  • the generated current estimation unit 230 can then use this calculated value as the upper limit value of the generated current (energy) of the secondary coil 152.
  • the dilution level setting unit 240 sets a target dilution level of the air-fuel mixture supplied into the cylinders of the internal combustion engine 100 based on the upper limit value of the generated current (energy) of the secondary coil 152 estimated by the generated current estimation unit 230. Set the value.
  • the dilution degree of the mixture is the EGR rate of the mixture and/or the air-fuel ratio of the mixture. As shown in FIG.
  • the generated current estimating unit 230 includes the relationship between the upper limit value of the generated current (energy) of the secondary coil 152 and the target value of the EGR rate of the air-fuel mixture, and/or the relationship between the upper limit value of the generated current (energy) of the secondary coil 152 and the target value of the EGR rate of the A map showing the relationship between the upper limit value of the generated current (energy) and the target value of the air-fuel ratio is provided in advance.
  • the dilution level setting unit 240 uses the map shown in FIG. 11 to determine the target value of the EGR rate and/or the target value of the air-fuel ratio of the air-fuel mixture from the estimated upper limit value of the current (energy) generated by the secondary coil 152. Set.
  • the dilution setting unit 240 sets the target value of the EGR rate of the mixture and/or the air-fuel ratio.
  • the target value of the EGR rate and/or the target value of the air-fuel ratio of the air-fuel mixture is set using the relationship of decreasing the target value.
  • the control device 200 of the second embodiment cannot secure the amount of energy supplied to the spark plug 105 necessary for stable combustion of the air-fuel mixture if the energization amount of the tertiary coil 153 is restricted (reduced).
  • the control device 200 of the second embodiment can achieve both stable combustion of the air-fuel mixture and prevention of failures due to heat generation of the ignition coil 150.
  • the generated current estimating section 230 and the dilution level setting section 240 may be included in the control device 200 of the first embodiment.
  • the temperature characteristic diagnosis section 250 diagnoses the temperature characteristic of the ignition coil 150, in which the length of the return signal changes depending on the coil temperature. Specifically, when it is assumed that the outside temperature and the coil temperature are equal, the temperature characteristic diagnosis unit 250 collects in advance the outside temperature and the length of the return signal in association with each other.
  • the time when the outside air temperature and the coil temperature are assumed to be equal is, for example, the timing immediately after the internal combustion engine 100 is started after the internal combustion engine 100 has stopped for a long time and the cooling water temperature and the outside air temperature have become equal.
  • the temperature characteristic diagnosis unit 250 calculates the relationship between the median value (or average value) of the collected outside air temperature and the median value (or average value) of the length of the return signal based on the median value (or average value) of the coil temperature. value) and the median value (or average value) of the length of the return signal, and is stored in advance.
  • the relationship between the median value (or average value) of the coil temperature and the median value (or average value) of the length of the return signal is such that the higher the coil temperature, the longer the length of the return signal. It is expressed as a linear relationship as shown in .
  • the temperature characteristic diagnosis unit 250 acquires the outside temperature and the length of the return signal, it passes through the acquired outside temperature and the length of the return signal and follows the dashed line shown in FIG. 12 stored in advance. A straight line with the same slope (solid line in FIG. 12) is identified. The temperature characteristic diagnosis unit 250 determines the relationship between the coil temperature indicated by the identified straight line and the length of the return signal as the temperature characteristic of the ignition coil 150 obtained by the current diagnosis.
  • the temperature estimating unit 210 of the control device 200 including the temperature characteristic diagnosing unit 250 can estimate the coil temperature based on the temperature characteristics obtained by the current diagnosis by the temperature characteristic diagnosing unit 250.
  • the temperature estimating unit 210 can estimate the coil temperature by taking into account the temperature characteristics of the ignition coil 150, which vary depending on the individual ignition coils 150, so that the accuracy of estimating the coil temperature can be further improved. Therefore, the control device 200 including the temperature characteristic diagnosis section 250 can more reliably prevent failures due to heat generation in the ignition coil 150 while ensuring the amount of energy supplied to the spark plug 105 necessary for stable combustion of the air-fuel mixture. Can be done.
  • the return signal is a signal that is output when the tertiary coil 153 is de-energized, as described above.
  • the return signal may be a signal that is output when the primary coil 151 is de-energized. That is, the return signal includes a primary return signal outputted from the primary coil 151 side to the control device 200 side in response to energization of the primary coil 151, and a primary return signal outputted from the tertiary coil 153 side in response to energization of the tertiary coil 153. and a tertiary return signal output from the side to the control device 200 side.
  • the temperature estimation unit 210 can estimate the coil temperature based on at least one of the primary return signal and the tertiary return signal.
  • the temperature estimation unit 210 can estimate the coil temperature based on the primary return signal from the primary coil 151 even if the tertiary return signal is not output from the tertiary coil 153 due to an unexpected situation. can. Therefore, the control device 200 can reliably and stably prevent failures due to heat generation in the ignition coil 150 while ensuring the amount of energy supplied to the spark plug 105 necessary for stable combustion of the air-fuel mixture.
  • the return signal is a signal that is output when the ignition coil 150 is de-energized, but the return signal is a detection signal of a temperature sensor that detects the coil temperature of the ignition coil 150. Good too.
  • the temperature estimation unit 210 can estimate the coil temperature based on the detection signal of this temperature sensor.
  • the temperature estimation unit 210 can obtain accurate coil temperature. Therefore, the control device 200 can more reliably prevent failures due to heat generation in the ignition coil 150 while ensuring the amount of energy supplied to the spark plug 105 necessary for stable combustion of the air-fuel mixture.
  • the present invention is not limited to the above-described embodiments, and includes various modifications.
  • the above embodiments have been described in detail to explain the present invention in an easy-to-understand manner, and the present invention is not necessarily limited to having all the configurations described.
  • each of the above-mentioned configurations, functions, processing units, processing means, etc. may be partially or entirely realized by hardware, for example, by designing an integrated circuit. Further, each of the above-mentioned configurations, functions, etc. may be realized by software by a processor interpreting and executing a program for realizing each function. Information such as programs, tapes, and files that implement each function can be stored in a memory, a recording device such as a hard disk, an SSD (solid state drive), or a recording medium such as an IC card, SD card, or DVD.
  • a recording device such as a hard disk, an SSD (solid state drive), or a recording medium such as an IC card, SD card, or DVD.
  • control lines and information lines are shown that are considered necessary for explanation, and not all control lines and information lines are necessarily shown in the product. In reality, almost all components may be considered to be interconnected.

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  • Chemical & Material Sciences (AREA)
  • Combustion & Propulsion (AREA)
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  • General Engineering & Computer Science (AREA)
  • Signal Processing (AREA)
  • Ignition Installations For Internal Combustion Engines (AREA)

Abstract

The purpose of the present invention is to provide an internal combustion engine control device that makes it possible both to achieve stable combustion of an air-fuel mixture and to prevent damage to an ignition coil caused by heat production. A control device 200 for an internal combustion engine 100 that comprises an ignition plug 105 and an ignition coil 150 comprises: a temperature estimation unit 210 that estimates a coil temperature that is the temperature in and around the ignition coil 150 of the internal combustion engine 100; and an ignition control unit 220 that controls energization of the ignition coil 150 and thereby controls the current supplied to the ignition plug 105. The ignition coil 150 has an increase mechanism that increases the current being supplied to the ignition plug 105. The ignition control unit 220 controls the increase in current by the increase mechanism such that the increase is smaller the higher the estimated coil temperature.

Description

内燃機関の制御装置Internal combustion engine control device
　本発明は、内燃機関の制御装置に関する。 The present invention relates to a control device for an internal combustion engine.
　自動車の更なる燃費向上及び排気清浄化のため、内燃機関の気筒内に供給される混合気を理論空燃比よりも大きく希薄にして燃焼する技術や、排気ガスを還流する排気再循環（Exhausted Gas Recirculation：ＥＧＲ）を使用した技術を導入した内燃機関の制御装置が知られている。 In order to further improve automobile fuel efficiency and purify exhaust gas, we are developing technology that burns the air-fuel mixture supplied into the cylinders of internal combustion engines at a much leaner ratio than the stoichiometric air-fuel ratio, and exhaust gas recirculation (exhaust gas recirculation) that recirculates exhaust gas. 2. Description of the Related Art A control device for an internal combustion engine that incorporates a technology using EGR (recirculation) is known.
　混合気の超希薄化及び高ＥＧＲ率化によって、混合気を安定的に燃焼するために点火プラグに供給するべきエネルギは増加する。点火プラグに供給されるエネルギを増加させる技術として、特許文献１がある。 By making the air-fuel mixture ultra-lean and increasing the EGR rate, the energy that must be supplied to the spark plug in order to stably burn the air-fuel mixture increases. There is Patent Document 1 as a technique for increasing the energy supplied to a spark plug.
　特許文献１に開示された内燃機関では、点火プラグにエネルギを与える点火コイルの１次側に主１次コイル及び副１次コイルを配置している。そして、特許文献１に開示された内燃機関の制御装置では、点火プラグに供給されるエネルギを増加させるために、主１次コイルの通電を遮断した後に副１次コイルを通電している。 In the internal combustion engine disclosed in Patent Document 1, a main primary coil and a sub-primary coil are arranged on the primary side of an ignition coil that provides energy to a spark plug. In the internal combustion engine control device disclosed in Patent Document 1, in order to increase the energy supplied to the spark plug, the sub-primary coil is energized after the main primary coil is de-energized.
国際公開第２０２１／０９５５０５号International Publication No. 2021/095505
　点火プラグへのエネルギ供給量を増加するために点火コイルの通電量を増加し過ぎると、点火コイルの発熱によって点火コイルの温度が過度に上昇してしまい、点火コイルが故障する可能性がある。したがって、点火コイルが最も厳しい使用環境で使用されても点火コイルが上限温度を超えないように、点火コイルの通電量の上限値を設定する必要がある。点火コイルの通電量の上限値はマージンを持たせて設定される。このマージンが大きすぎると、点火コイルの通電量が大きく制限させて、点火プラグへのエネルギ供給量も大きく制限される。この制限によって、特許文献１のように主１次コイル及び副１次コイルを有する点火コイルでは、主１次コイルの通電量を補助するべく副１次コイルを通電したい時に、副１次コイルに通電できない場合が生じる。これにより、特許文献１に開示された内燃機関の制御装置では、混合気を安定的に燃焼するために必要な点火プラグへのエネルギ供給量を確保できない場合が生じる。よって、特許文献１に開示された内燃機関の制御装置は、混合気の安定的燃焼と点火コイルの発熱による故障防止との両立を図る点において、改善の余地がある。 If the amount of current applied to the ignition coil is increased too much in order to increase the amount of energy supplied to the spark plug, the temperature of the ignition coil will rise excessively due to the heat generated by the ignition coil, which may cause the ignition coil to malfunction. Therefore, it is necessary to set an upper limit value for the amount of current applied to the ignition coil so that the ignition coil does not exceed the upper limit temperature even when the ignition coil is used in the harshest usage environment. The upper limit value of the amount of current applied to the ignition coil is set with a margin. If this margin is too large, the amount of current supplied to the ignition coil will be greatly restricted, and the amount of energy supplied to the spark plug will also be greatly restricted. Due to this restriction, in an ignition coil that has a main primary coil and a sub-primary coil as in Patent Document 1, when it is desired to energize the sub-primary coil to supplement the amount of current flowing through the main primary coil, the sub-primary coil is There may be cases where power cannot be applied. As a result, the internal combustion engine control device disclosed in Patent Document 1 may not be able to secure the amount of energy supplied to the spark plug necessary for stably burning the air-fuel mixture. Therefore, the internal combustion engine control device disclosed in Patent Document 1 has room for improvement in terms of achieving both stable combustion of the air-fuel mixture and prevention of failures due to heat generation of the ignition coil.
　本発明は、上記に鑑みてなされたものであり、混合気の安定的燃焼と点火コイルの発熱による故障防止との両立を図ることが可能な内燃機関の制御装置を提供することを目的とする。 The present invention has been made in view of the above, and an object of the present invention is to provide a control device for an internal combustion engine that can achieve both stable combustion of an air-fuel mixture and prevention of failures due to heat generation of an ignition coil. .
　上記課題を解決するために、本発明の内燃機関の制御装置は、点火プラグ及び点火コイルを備えた内燃機関の制御装置であって、前記点火コイルの内部又は周囲の温度であるコイル温度を推定する温度推定部と、前記点火コイルの通電を制御することによって前記点火プラグに供給される電流を制御する点火制御部と、を備え、前記点火コイルは、前記点火プラグに前記電流を供給中に当該電流を増加させる増加機構を有し、前記点火制御部は、推定された前記コイル温度の温度が高いほど、前記増加機構による前記電流の増加量が小さくなるように前記増加量を制御することを特徴とする。 In order to solve the above problems, the present invention provides an internal combustion engine control device that includes an ignition plug and an ignition coil, and estimates a coil temperature that is the temperature inside or around the ignition coil. and an ignition control unit that controls the current supplied to the spark plug by controlling energization of the ignition coil, and the ignition coil is configured to an increasing mechanism that increases the current, and the ignition control unit controls the increasing amount such that the higher the estimated coil temperature, the smaller the increasing amount of the current by the increasing mechanism. It is characterized by
　本発明によれば、混合気の安定的燃焼と点火コイルの発熱による故障防止との両立を図ることが可能な内燃機関の制御装置を提供することができる。
　上記以外の課題、構成および効果は、以下の実施形態の説明により明らかにされる。 According to the present invention, it is possible to provide a control device for an internal combustion engine that can achieve both stable combustion of an air-fuel mixture and prevention of failures due to heat generation of an ignition coil.
Problems, configurations, and effects other than those described above will be made clear by the description of the embodiments below.
本実施形態の制御装置を備えた内燃機関システムの概略構成を示す図。1 is a diagram showing a schematic configuration of an internal combustion engine system including a control device according to the present embodiment. 図１に示す点火コイル及び点火コイル通電回路の概略構成を示す図。2 is a diagram showing a schematic configuration of an ignition coil and an ignition coil energization circuit shown in FIG. 1. FIG. 点火コイル及び点火コイル通電回路の動作を説明する図。FIG. 3 is a diagram illustrating the operation of an ignition coil and an ignition coil energization circuit. 実施形態１の制御装置の機能的構成を示すブロック図。1 is a block diagram showing a functional configuration of a control device according to a first embodiment; FIG. 図４に示す温度推定部の詳細構成を示すブロック図。FIG. 5 is a block diagram showing a detailed configuration of the temperature estimation section shown in FIG. 4. FIG. 図６（ａ）は１次コイルの通電量と混合気の希釈度と内燃機関の回転数との関係を示すマップを説明する図、図６（ｂ）は３次コイルの通電量と混合気の希釈度と内燃機関の回転数との関係を示すマップを説明する図。Figure 6(a) is a diagram illustrating a map showing the relationship between the energization amount of the primary coil, the dilution of the mixture, and the rotational speed of the internal combustion engine, and FIG. 6(b) is a diagram illustrating the relationship between the energization amount of the tertiary coil and the mixture FIG. 3 is a diagram illustrating a map showing the relationship between the degree of dilution and the rotational speed of an internal combustion engine. 図７（ａ）はコイル温度に応じた３次コイルの通電量の制御例を説明する図、図７（ｂ）はコイル温度に応じた１次コイル及び３次コイルの各通電量の制御例を説明する図。FIG. 7(a) is a diagram illustrating an example of controlling the energization amount of the tertiary coil according to the coil temperature, and FIG. 7(b) is an example of controlling the energization amount of each of the primary coil and the tertiary coil according to the coil temperature. A diagram explaining. 実施形態２の制御装置の機能的構成を示すブロック図。FIG. 3 is a block diagram showing the functional configuration of a control device according to a second embodiment. 図９（ａ）はリターン信号の長さとコイル温度との関係を説明する図、図９（ｂ）はリターン信号の長さを説明する図。FIG. 9(a) is a diagram illustrating the relationship between the length of the return signal and the coil temperature, and FIG. 9(b) is a diagram illustrating the length of the return signal. １次コイル又は３次コイルの通電量と、２次コイルの発生電流（エネルギ）との関係を示すマップを説明する図。The figure explaining the map which shows the relationship between the amount of energization of a primary coil or a tertiary coil, and the generated electric current (energy) of a secondary coil. ２次コイルの発生電流（エネルギ）の上限値と、混合気のＥＧＲ率の目標値及び／又は空燃比の目標値との関係を示すマップを説明する図。FIG. 3 is a diagram illustrating a map showing the relationship between the upper limit value of the current (energy) generated by a secondary coil and the target value of the EGR rate and/or the target value of the air-fuel ratio of the air-fuel mixture. 温度特性診断部を説明する図。FIG. 3 is a diagram illustrating a temperature characteristic diagnosis section.
　以下、本発明の実施形態について図面を用いて説明する。なお、各実施形態において同一の符号を付された構成については、特に言及しない限り、各実施形態において同様の機能を有し、その説明を省略する。 Hereinafter, embodiments of the present invention will be described using the drawings. In addition, unless otherwise mentioned, the configurations with the same reference numerals in each embodiment have the same functions in each embodiment, and the description thereof will be omitted.
［実施形態１］
　図１～図７を用いて、実施形態１の内燃機関１００の制御装置２００について説明する。 [Embodiment 1]
A control device 200 for an internal combustion engine 100 according to a first embodiment will be described using FIGS. 1 to 7.
　図１は、本実施形態の制御装置２００を備えた内燃機関システム１の概略構成を示す図である。 FIG. 1 is a diagram showing a schematic configuration of an internal combustion engine system 1 including a control device 200 of this embodiment.
　内燃機関１００は、制御装置（Engine Control Unit：ＥＣＵ）２００と、アクセル開度を検出するアクセル開度センサ１４０とにより制御される。内燃機関１００は、気筒（シリンダ）内に、ピストン１０１、吸気バルブ１０２及び排気バルブ１０３を備えている。内燃機関１００は、一例としては、複数、例えば４個の気筒を有した内燃機関とすることができるが、図１は、複数の気筒のうちの１つの気筒のみを代表的に図示している。 The internal combustion engine 100 is controlled by an engine control unit (ECU) 200 and an accelerator opening sensor 140 that detects the accelerator opening. The internal combustion engine 100 includes a piston 101, an intake valve 102, and an exhaust valve 103 in a cylinder. As an example, the internal combustion engine 100 can be an internal combustion engine having a plurality of cylinders, for example, four cylinders, but FIG. 1 representatively shows only one cylinder among the plurality of cylinders. .
　ピストン１０１は、不図示のクランクシャフトが接続されている。クランクシャフトはメインシャフトとサブシャフトとにより構成される。サブシャフトは、コネクティングロッドを介してピストン１０１に連結されている。クランクシャフトは、メインシャフトとサブシャフトとの距離、或いは、コネクティングロッドの長さを可変とする可変圧縮比機構を備えてもよい。内燃機関１００は、可変圧縮比機構を備えることにより、ピストン１０１のストローク量を変更することができ、燃焼室Ｒ１内の圧力を可変とすることができる。 A crankshaft (not shown) is connected to the piston 101. The crankshaft is composed of a main shaft and a subshaft. The subshaft is connected to the piston 101 via a connecting rod. The crankshaft may include a variable compression ratio mechanism that changes the distance between the main shaft and the subshaft or the length of the connecting rod. By including the variable compression ratio mechanism, the internal combustion engine 100 can change the stroke amount of the piston 101, and can make the pressure within the combustion chamber R1 variable.
　シリンダヘッドには、点火プラグ１０５と点火コイル１５０とが設けられている。更に、シリンダヘッドには、気筒内の燃焼室Ｒ１内に燃料を直接噴射する燃料噴射弁１０７が設けられている。図示は省略するが、気筒のウォータジャケットには、冷却水の温度を検出する水温センサが備えられている。 A spark plug 105 and an ignition coil 150 are provided in the cylinder head. Further, the cylinder head is provided with a fuel injection valve 107 that directly injects fuel into the combustion chamber R1 within the cylinder. Although not shown, the water jacket of the cylinder is equipped with a water temperature sensor that detects the temperature of cooling water.
　また、吸気バルブ１０２の上流側には、内燃機関１００に吸入される空気を導入する吸気管１１０が設けられている。排気バルブ１０３の下流側には、気筒から排出される排気ガスを外部に排出する排気管１１１が設けられている。吸気管１１０には、吸気ガスを冷却するインタークーラ１１２、アクセル開度に応じて吸気量を調節するスロットルバルブ１１３、吸気ガスの流れを調節するためのサージタンク１１４、及び、吸気管１１０の一部狭めて吸気ガス流に乱れ（タンブル）を生じさせるタンブル制御バルブ（ＴＣＶ）１１５が設けられている。 Furthermore, an intake pipe 110 is provided upstream of the intake valve 102 to introduce air to be taken into the internal combustion engine 100. An exhaust pipe 111 is provided on the downstream side of the exhaust valve 103 to discharge exhaust gas discharged from the cylinder to the outside. The intake pipe 110 includes an intercooler 112 that cools the intake gas, a throttle valve 113 that adjusts the amount of intake air according to the accelerator opening, a surge tank 114 that adjusts the flow of the intake gas, and a portion of the intake pipe 110. A tumble control valve (TCV) 115 is provided which narrows the intake gas flow and causes turbulence (tumble) in the intake gas flow.
　また、排気管１１１は、排気通路１２１に連通されている。排気通路１２１には、三元触媒１２３と、空燃比センサ１２４と、タービン１２５ｂとが設けられている。三元触媒１２３は、排気ガスを浄化するためのものである。空燃比センサ１２４は、排気ガスの空燃比を検出するセンサである。また、タービン１２５ｂは、排気ガスのエネルギを利用してコンプレッサ１２５ａを駆動するための駆動力を発生させる。 Furthermore, the exhaust pipe 111 is communicated with an exhaust passage 121. The exhaust passage 121 is provided with a three-way catalyst 123, an air-fuel ratio sensor 124, and a turbine 125b. The three-way catalyst 123 is for purifying exhaust gas. The air-fuel ratio sensor 124 is a sensor that detects the air-fuel ratio of exhaust gas. Further, the turbine 125b uses the energy of the exhaust gas to generate driving force for driving the compressor 125a.
　なお、排気通路１２１は、三元触媒１２３の下流側においてＥＧＲ配管１２６に分岐している。ＥＧＲ配管１２６は、排気ガスをＥＧＲガスとして吸気側に再循環させるための配管である。ＥＧＲ配管１２６は、吸気管１１０に連通する吸気通路１３０に接続されている。ＥＧＲ配管１２６には、ＥＧＲガスを冷却するＥＧＲクーラ１２７と、ＥＧＲガス量を調整するＥＧＲバルブ１２８と、ＥＧＲバルブ１２８の前後の圧力を検出する圧力センサ１３３と、が設けられている。また、排気通路１２１のＥＧＲ配管１２６との分岐点よりも更に下流側には、三元触媒１２３とは別の三元触媒１２９が備えられている。 Note that the exhaust passage 121 branches into an EGR pipe 126 on the downstream side of the three-way catalyst 123. The EGR pipe 126 is a pipe for recirculating exhaust gas to the intake side as EGR gas. The EGR pipe 126 is connected to an intake passage 130 that communicates with the intake pipe 110. The EGR pipe 126 is provided with an EGR cooler 127 that cools the EGR gas, an EGR valve 128 that adjusts the amount of EGR gas, and a pressure sensor 133 that detects the pressure before and after the EGR valve 128. Furthermore, a three-way catalyst 129 different from the three-way catalyst 123 is provided further downstream of the branch point of the exhaust passage 121 with the EGR pipe 126.
　吸気管１１０は、コンプレッサ１２５ａ側において吸気通路１３０に連通されている。吸気通路１３０には、空気流量を計測するエアフローセンサ１３１と、吸気圧を調整する圧力調整バルブ１３２とが設けられている。また、吸気管１１０には、吸気ガス（吸気通路１３０から供給された吸入空気とＥＧＲガスとを混合させたガス）の酸素濃度を検出する酸素濃度センサ１３４が設けられている。 The intake pipe 110 is communicated with an intake passage 130 on the compressor 125a side. The intake passage 130 is provided with an air flow sensor 131 that measures the air flow rate and a pressure adjustment valve 132 that adjusts the intake pressure. Further, the intake pipe 110 is provided with an oxygen concentration sensor 134 that detects the oxygen concentration of intake gas (a gas obtained by mixing intake air supplied from the intake passage 130 and EGR gas).
　吸気ガスは、インタークーラ１１２、吸気管１１０、サージタンク１１４、タンブルバルブ１１５及び吸気バルブ１０２を経て、燃焼室Ｒ１内に流入する。燃焼室Ｒ１内に流入された吸気ガスは、燃料噴射弁１０７から燃料が噴射されて、混合気を構成する。混合気は、所定の点火時期で点火プラグ１０５から発生される火花により着火及び燃焼する。この混合気の燃焼により発生する燃焼圧がピストン１０１を押し下げることによって、内燃機関１００は動力を発生する。 The intake gas flows into the combustion chamber R1 through the intercooler 112, the intake pipe 110, the surge tank 114, the tumble valve 115, and the intake valve 102. Fuel is injected from the fuel injection valve 107 into the intake gas that has flowed into the combustion chamber R1 to form an air-fuel mixture. The air-fuel mixture is ignited and combusted by a spark generated from the spark plug 105 at a predetermined ignition timing. The internal combustion engine 100 generates power as the combustion pressure generated by combustion of the air-fuel mixture pushes down the piston 101.
　燃焼後の排気ガスは、排気バルブ１０３、排気管１１１及びタービン１２５ｂを経て、三元触媒１２３に送られ、三元触媒１２３内においてＮＯｘ、ＣＯ、ＨＣ成分が浄化される。その後、排気ガスは、排気通路１２１を経て三元触媒１２９に送られ、三元触媒１２９内において再度浄化されて外部に排出される。 The exhaust gas after combustion is sent to the three-way catalyst 123 via the exhaust valve 103, the exhaust pipe 111, and the turbine 125b, and NOx, CO, and HC components are purified within the three-way catalyst 123. Thereafter, the exhaust gas is sent to the three-way catalyst 129 through the exhaust passage 121, purified again within the three-way catalyst 129, and discharged to the outside.
　また、排気ガスの一部は、ＥＧＲガスとして、ＥＧＲ配管１２６、ＥＧＲクーラ１２７及びＥＧＲバルブ１２８を経て、吸気通路１３０に導入される。吸気通路１３０に導入されたＥＧＲガスは、吸入空気と合流し、吸入空気とＥＧＲガスとが混合された吸気ガスを構成する。吸気ガスは、吸気管１１０等を通過して燃焼室Ｒ１に到達する。 Further, a part of the exhaust gas is introduced into the intake passage 130 as EGR gas through the EGR pipe 126, the EGR cooler 127, and the EGR valve 128. The EGR gas introduced into the intake passage 130 merges with the intake air to form intake gas in which the intake air and EGR gas are mixed. The intake gas passes through the intake pipe 110 and the like and reaches the combustion chamber R1.
　制御装置２００は、ＣＰＵ等のプロセッサと、ＲＯＭ及びＲＡＭ等の記憶装置と、を備えた電子制御ユニットによって構成される。制御装置２００は、ＲＯＭに記憶されたプログラムをＣＰＵが実行することによって制御装置２００の機能を実現する。具体的には、制御装置２００は、アクセル開度センサ１４０の検出信号や各種センサ信号に基づいて、要求トルクを演算する。制御装置２００は、各種センサの検出信号から得られる内燃機関１００の運転状態及び内燃機関１００の運転条件に基づいて、圧力調整バルブ１３２の開度、スロットルバルブ１１３の開度、燃料噴射弁１０７の噴射パルス期間、点火プラグ１０５の点火時期、吸気バルブ１０２及び排気バルブ１０３の開閉時期、並びに、ＥＧＲバルブ１２８の開度等の、内燃機関１００の主要な作動量を演算する。 The control device 200 is configured by an electronic control unit including a processor such as a CPU, and a storage device such as a ROM and a RAM. The control device 200 realizes the functions of the control device 200 by the CPU executing a program stored in the ROM. Specifically, the control device 200 calculates the required torque based on the detection signal of the accelerator opening sensor 140 and various sensor signals. The control device 200 controls the opening degree of the pressure regulating valve 132, the opening degree of the throttle valve 113, and the opening degree of the fuel injection valve 107 based on the operating state of the internal combustion engine 100 and the operating conditions of the internal combustion engine 100 obtained from detection signals of various sensors. The main operating quantities of the internal combustion engine 100, such as the injection pulse period, the ignition timing of the spark plug 105, the opening/closing timing of the intake valve 102 and the exhaust valve 103, and the opening degree of the EGR valve 128, are calculated.
　図２は、図１に示す点火コイル１５０及び点火コイル通電回路１６０の概略構成を示す図である。図３は、点火コイル１５０及び点火コイル通電回路１６０の動作を説明する図である。 FIG. 2 is a diagram showing a schematic configuration of the ignition coil 150 and the ignition coil energization circuit 160 shown in FIG. 1. FIG. 3 is a diagram illustrating the operation of the ignition coil 150 and the ignition coil energization circuit 160.
　点火コイル１５０は、点火プラグ１０５が混合気に点火して混合気を燃焼させるために必要な電流（エネルギ）を点火プラグ１０５に供給する変圧器を構成する。点火コイル１５０は、変圧器の１次側に配置された１次コイル１５１と、変圧器の２次側に配置され点火プラグ１０５に接続された２次コイル１５２と、変圧器の１次側に配置された３次コイル１５３と、を有する。１次コイル１５１、２次コイル１５２及び３次コイル１５３は、同一のコアに巻き付けられている。２次コイル１５２の巻き数は、１次コイル１５１及び３次コイル１５３の合計巻き数よりも多い。 The ignition coil 150 constitutes a transformer that supplies the ignition plug 105 with the current (energy) necessary for the ignition plug 105 to ignite the air-fuel mixture and combust the air-fuel mixture. The ignition coil 150 includes a primary coil 151 placed on the primary side of the transformer, a secondary coil 152 placed on the secondary side of the transformer and connected to the spark plug 105, and a secondary coil 152 placed on the primary side of the transformer. It has a tertiary coil 153 arranged. The primary coil 151, the secondary coil 152, and the tertiary coil 153 are wound around the same core. The number of turns of the secondary coil 152 is greater than the total number of turns of the primary coil 151 and the tertiary coil 153.
　点火コイル通電回路１６０は、１次コイル通電回路１６１と、３次コイル通電回路１６２と、３次電流監視回路１６３と、を有する。 The ignition coil energization circuit 160 includes a primary coil energization circuit 161, a tertiary coil energization circuit 162, and a tertiary current monitoring circuit 163.
　１次コイル通電回路１６１は、制御装置２００からの１次コイル通電信号に基づいて、１次コイル１５１を通電する回路である。３次コイル通電回路１６２は、制御装置２００からの３次コイル通電信号に基づいて、３次コイル１５３を通電する回路である。１次コイル通電回路１６１及び３次コイル通電回路１６２のそれぞれは、例えば、イグナイタ等を含んで構成される。 The primary coil energization circuit 161 is a circuit that energizes the primary coil 151 based on a primary coil energization signal from the control device 200. The tertiary coil energization circuit 162 is a circuit that energizes the tertiary coil 153 based on a tertiary coil energization signal from the control device 200. Each of the primary coil energizing circuit 161 and the tertiary coil energizing circuit 162 includes, for example, an igniter.
　３次電流監視回路１６３は、３次コイル１５３に流れる電流（「３次電流」とも称する）を監視する。具体的には、３次電流監視回路１６３は、３次コイル１５３に流れる電流を検出すると共に３次コイル１５３からのリターン信号を検出し、制御装置２００に出力する。リターン信号とは、点火コイル１５０の通電に応答して点火コイル１５０側から制御装置２００側に出力される信号である。本実施形態のリターン信号は、３次コイル１５３の通電が停止すると、特に通電が異常停止すると、出力される。したがって、本実施形態のリターン信号は、３次コイル１５３の診断結果を示す信号（「診断信号」とも称する）といえる。 The tertiary current monitoring circuit 163 monitors the current flowing through the tertiary coil 153 (also referred to as "tertiary current"). Specifically, the tertiary current monitoring circuit 163 detects the current flowing through the tertiary coil 153 and also detects a return signal from the tertiary coil 153, and outputs it to the control device 200. The return signal is a signal output from the ignition coil 150 side to the control device 200 side in response to energization of the ignition coil 150. The return signal of this embodiment is output when the energization of the tertiary coil 153 stops, particularly when the energization stops abnormally. Therefore, the return signal of this embodiment can be said to be a signal indicating the diagnosis result of the tertiary coil 153 (also referred to as a "diagnosis signal").
　点火プラグ１０５の点火時、制御装置２００は、１次コイル通電信号を１次コイル通電回路１６１に出力し、１次コイル１５１を通電させる。１次コイル通電信号は、図３の上段に示すように、１次コイル１５１の通電期間にハイレベルを示し、１次コイル１５１の非通電期間にローレベルを示すパルス信号であってもよい。１次コイル１５１の通電期間は、１次コイル１５１の通電量に応じて設定され、ドエルアングル（Ｄｗｅｌｌ）に適合する。 When the spark plug 105 is ignited, the control device 200 outputs a primary coil energization signal to the primary coil energization circuit 161 to energize the primary coil 151. As shown in the upper part of FIG. 3, the primary coil energization signal may be a pulse signal that exhibits a high level when the primary coil 151 is energized and a low level when the primary coil 151 is not energized. The energization period of the primary coil 151 is set according to the amount of energization of the primary coil 151, and is adapted to the dwell angle.
　１次コイル１５１が通電されると（通電が開始されて停止されると）、電磁誘導によって２次コイル１５２に電流が発生し、発生した電流が点火プラグ１０５に供給される。２次コイル１５２の発生電流は、図３の下段に示すように、１次コイル１５１の通電期間に応じた大電流となり、時間の経過に伴って低下していく。 When the primary coil 151 is energized (when energization is started and stopped), a current is generated in the secondary coil 152 by electromagnetic induction, and the generated current is supplied to the spark plug 105. As shown in the lower part of FIG. 3, the current generated by the secondary coil 152 becomes a large current corresponding to the energization period of the primary coil 151, and decreases as time passes.
　内燃機関１００の運転条件及び混合気の希釈度（ＥＧＲ率及び／又は空燃比）によっては、１次コイル１５１の通電だけでは、混合気の安定的燃焼に必要な点火プラグ１０５へのエネルギ供給量が不足する場合がある。この場合、制御装置２００は、１次コイル１５１の通電によって点火プラグ１０５に電流を供給中に、３次コイル通電信号を３次コイル通電回路１６２に出力して、３次コイル１５３を通電させる。３次コイル通電信号は、図３の中段に示すように、３次コイル１５３の通電期間にハイレベルを示し、３次コイル１５３の非通電期間にローレベルを示すパルス信号であってもよい。３次コイル１５３の通電期間は、３次コイル１５３の通電量に応じて設定される。３次コイル１５３の通電量及び通電時期は、点火プラグ１０５へのエネルギ供給量が不足する量及び時期に応じて設定される。３次コイル１５３の通電期間は、１次コイル１５１の通電に３次コイル１５３の通電を重ねることから、重ね期間とも称される。 Depending on the operating conditions of the internal combustion engine 100 and the degree of dilution of the air-fuel mixture (EGR rate and/or air-fuel ratio), energizing the primary coil 151 alone may not be enough to supply the amount of energy to the spark plug 105 necessary for stable combustion of the air-fuel mixture. There may be a shortage. In this case, while supplying current to the spark plug 105 by energizing the primary coil 151, the control device 200 outputs a tertiary coil energization signal to the tertiary coil energization circuit 162 to energize the tertiary coil 153. The tertiary coil energization signal may be a pulse signal that exhibits a high level during the energization period of the tertiary coil 153 and a low level during the non-energization period of the tertiary coil 153, as shown in the middle part of FIG. The energization period of the tertiary coil 153 is set according to the amount of energization of the tertiary coil 153. The amount and timing of energization of the tertiary coil 153 are set according to the amount and timing of the shortage of energy supplied to the spark plug 105. The energization period of the tertiary coil 153 is also referred to as an overlapping period because the energization of the primary coil 151 and the energization of the tertiary coil 153 overlap.
　１次コイル１５１の通電によって点火プラグ１０５に電流を供給中に３次コイル１５３が通電されると、電磁誘導によって２次コイル１５２に電流が発生し、発生した電流が点火プラグ１０５に供給される。２次コイル１５２の発生電流は、図３の下段に示すように、１次コイル１５１の通電に応じた電流に、３次コイル１５３の通電に応じた電流が重畳される。これにより、点火プラグ１０５に供給される電流は増加する。 When the tertiary coil 153 is energized while the primary coil 151 is supplying current to the ignition plug 105, a current is generated in the secondary coil 152 by electromagnetic induction, and the generated current is supplied to the ignition plug 105. . As shown in the lower part of FIG. 3, the current generated by the secondary coil 152 is such that a current corresponding to the energization of the tertiary coil 153 is superimposed on a current corresponding to the energization of the primary coil 151. As a result, the current supplied to the spark plug 105 increases.
　このように、本実施形態の点火コイル１５０は、点火プラグ１０５に電流を供給中に当該電流を増加させる増加機構として、３次コイル１５３を有する。但し、この増加機構は、３次コイル１５３に限定されない。 In this way, the ignition coil 150 of this embodiment has the tertiary coil 153 as an increasing mechanism that increases the current while it is being supplied to the spark plug 105. However, this increasing mechanism is not limited to the tertiary coil 153.
　図４は、実施形態１の制御装置２００の機能的構成を示すブロック図である。図５は、図４に示す温度推定部２１０の詳細構成を示すブロック図である。図６（ａ）は、１次コイル１５１の通電量と混合気の希釈度と内燃機関１００の回転数との関係を示すマップを説明する図である。図６（ｂ）は、３次コイル１５３の通電量と混合気の希釈度と内燃機関１００の回転数との関係を示すマップを説明する図である。図７（ａ）は、コイル温度に応じた３次コイル１５３の通電量の制御例を説明する図である。図７（ｂ）は、コイル温度に応じた１次コイル１５１及び３次コイル１５３の各通電量の制御例を説明する図である。 FIG. 4 is a block diagram showing the functional configuration of the control device 200 of the first embodiment. FIG. 5 is a block diagram showing the detailed configuration of temperature estimating section 210 shown in FIG. 4. As shown in FIG. FIG. 6A is a diagram illustrating a map showing the relationship between the amount of current applied to the primary coil 151, the degree of dilution of the air-fuel mixture, and the rotational speed of the internal combustion engine 100. FIG. 6B is a diagram illustrating a map showing the relationship between the amount of current applied to the tertiary coil 153, the degree of dilution of the air-fuel mixture, and the rotational speed of the internal combustion engine 100. FIG. 7A is a diagram illustrating an example of controlling the amount of current applied to the tertiary coil 153 according to the coil temperature. FIG. 7B is a diagram illustrating an example of controlling the amount of current applied to the primary coil 151 and the tertiary coil 153 according to the coil temperature.
　制御装置２００は、図４に示すように、温度推定部２１０と、点火制御部２２０と、を備える。 As shown in FIG. 4, the control device 200 includes a temperature estimation section 210 and an ignition control section 220.
　温度推定部２１０は、点火プラグ１０５の内部又は周囲の温度であるコイル温度を推定する。温度推定部２１０は、内燃機関１００の運転条件、内燃機関１００の冷却水温度、及び、点火コイル１５０の通電量に基づいて、コイル温度を推定する。 The temperature estimation unit 210 estimates the coil temperature, which is the temperature inside or around the spark plug 105. The temperature estimation unit 210 estimates the coil temperature based on the operating conditions of the internal combustion engine 100, the cooling water temperature of the internal combustion engine 100, and the amount of current applied to the ignition coil 150.
　温度推定部２１０は、図５に示すように、発熱量計算部２１１と、放熱量計算部２１２と、温度計算部２１３と、温度更新部２１４と、を有する。 As shown in FIG. 5, the temperature estimation section 210 includes a heat generation amount calculation section 211, a heat radiation amount calculation section 212, a temperature calculation section 213, and a temperature update section 214.
　発熱量計算部２１１は、点火コイル１５０の通電量及び内燃機関１００の運転条件に基づいて、点火コイル１５０の発熱量Ｑｃ（Ｊ）を計算する。具体的には、発熱量計算部２１１には、図５に示すように、１次コイル１５１及び３次コイル１５３の各通電量と１点火当たりの点火コイル１５０の発熱量との関係を示す発熱量マップが予め設けられている。発熱量計算部２１１は、この発熱量マップを用いて、１次コイル１５１及び３次コイル１５３の各通電量から、１点火当たりの点火コイル１５０の発熱量を特定する。そして、発熱量計算部２１１は、式（１）を用いて、点火コイル１５０の発熱量Ｑｃ（Ｊ）を計算する。
　　発熱量Ｑｃ（Ｊ）＝ｑｃ（Ｊ／点火）×Δｔ×回転数（ｒｐｍ）／１２０　　…（１）
　式（１）において、ｑｃ（Ｊ／点火）は、１点火当たりの点火コイル１５０の発熱量である。Δｔは、コイル温度の計算間隔（ｓ）である。 The calorific value calculation unit 211 calculates the calorific value Qc(J) of the ignition coil 150 based on the amount of current applied to the ignition coil 150 and the operating conditions of the internal combustion engine 100. Specifically, as shown in FIG. 5, the calorific value calculation unit 211 stores a calorific value indicating the relationship between the amount of energization of the primary coil 151 and the tertiary coil 153 and the calorific value of the ignition coil 150 per ignition. A quantity map is provided in advance. The calorific value calculation unit 211 uses this calorific value map to specify the calorific value of the ignition coil 150 per ignition from the respective energization amounts of the primary coil 151 and the tertiary coil 153. Then, the calorific value calculation unit 211 calculates the calorific value Qc(J) of the ignition coil 150 using equation (1).
Calorific value Qc (J) = qc (J/ignition) x Δt x rotation speed (rpm)/120...(1)
In equation (1), qc (J/ignition) is the amount of heat generated by the ignition coil 150 per ignition. Δt is the coil temperature calculation interval (s).
　放熱量計算部２１２は、内燃機関１００の冷却水温度（又はエンジンルーム温度）及び前回計算されたコイル温度に基づいて、点火コイル１５０の放熱量Ｑｌ（Ｊ）を計算する。具体的には、放熱量計算部２１２は、式（２）を用いて、点火コイル１５０の放熱量Ｑｌ（Ｊ）を計算する。
　　放熱量Ｑｌ（Ｊ）＝Ａｈ（Ｔｃ－Ｔｒ）×Δｔ　　…（２）
　式（２）において、Ａは、点火コイル１５０の表面積（ｍ２）である。ｈは、熱伝達率（Ｊ／ｓ／ｍ２）である。熱伝達率ｈは、予め実験等により定められている。Ｔｃは、前回計算されたコイル温度（℃）である。Ｔｒは、冷却水温度（又はエンジンルーム温度）（℃）である。 The heat radiation amount calculation unit 212 calculates the heat radiation amount Ql (J) of the ignition coil 150 based on the cooling water temperature (or engine room temperature) of the internal combustion engine 100 and the previously calculated coil temperature. Specifically, the heat radiation amount calculation unit 212 calculates the heat radiation amount Ql(J) of the ignition coil 150 using equation (2).
Amount of heat dissipation Ql (J) = Ah (Tc - Tr) x Δt...(2)
In equation (2), A is the surface area (m 2 ) of the ignition coil 150. h is the heat transfer coefficient (J/s/m 2 ). The heat transfer coefficient h is determined in advance through experiments and the like. Tc is the previously calculated coil temperature (°C). Tr is the cooling water temperature (or engine room temperature) (°C).
　温度計算部２１３は、点火コイル１５０の発熱量Ｑｃ（Ｊ）及び放熱量Ｑｌ（Ｊ）から、コイル温度Ｔｃ’を計算する。具体的には、温度計算部２１３は、式（３）を用いて、コイル温度Ｔｃ’を計算する。
　　コイル温度Ｔｃ’＝Ｔｃ＋（Ｑｃ－Ｑｌ）／Ｃ　　…（３）
　式（３）において、Ｃは、点火コイル１５０の熱容量（Ｊ／ｋｇ）である。 The temperature calculation unit 213 calculates the coil temperature Tc' from the heat generation amount Qc (J) and the heat radiation amount Ql (J) of the ignition coil 150. Specifically, the temperature calculation unit 213 calculates the coil temperature Tc' using equation (3).
Coil temperature Tc'=Tc+(Qc-Ql)/C...(3)
In equation (3), C is the heat capacity (J/kg) of the ignition coil 150.
　温度更新部２１４は、温度計算部２１３によって今回計算されたコイル温度Ｔｃ’を用いて、前回計算されたコイル温度Ｔｃを更新し、記憶する。 The temperature update unit 214 updates and stores the previously calculated coil temperature Tc using the coil temperature Tc' currently calculated by the temperature calculation unit 213.
　このようにして、温度推定部２１０は、内燃機関１００の運転条件、内燃機関１００の冷却水温度、及び、点火コイル１５０の通電量に基づいて、コイル温度を推定することができる。 In this way, the temperature estimation unit 210 can estimate the coil temperature based on the operating conditions of the internal combustion engine 100, the cooling water temperature of the internal combustion engine 100, and the amount of current flowing through the ignition coil 150.
　これにより、制御装置２００は、温度センサ及び温度検出回路等のハードウェアを追加することなく点火コイル１５０の温度を把握することができる。したがって、制御装置２００は、混合気の安定的燃焼に必要な点火プラグ１０５へのエネルギ供給量を確保しながら、点火コイル１５０の発熱による故障を容易に防止することができる。 Thereby, the control device 200 can grasp the temperature of the ignition coil 150 without adding hardware such as a temperature sensor and a temperature detection circuit. Therefore, the control device 200 can easily prevent failures due to heat generation in the ignition coil 150 while ensuring the amount of energy supplied to the spark plug 105 necessary for stable combustion of the air-fuel mixture.
　点火制御部２２０は、点火コイル１５０の通電を制御することによって点火プラグ１０５に供給される電流を制御する。具体的には、点火制御部２２０は、内燃機関１００の運転条件及び混合気の希釈度に基づいて、１次コイル１５１の通電量を設定する。例えば、点火制御部２２０には、図６（ａ）に示すように、１次コイル１５１の通電量と混合気の希釈度と内燃機関１００の回転数との関係を示すマップが予め設けられている。点火制御部２２０は、図６（ａ）に示すマップを用いて、内燃機関１００の回転数及び混合気の希釈度から、今回の通電に用いる１次コイル１５１の通電量を設定する。点火制御部２２０は、設定された１次コイル１５１の通電量に応じて１次コイル通電信号を生成し、１次コイル通電回路１６１に出力する。 The ignition control unit 220 controls the current supplied to the spark plug 105 by controlling the energization of the ignition coil 150. Specifically, the ignition control unit 220 sets the amount of current applied to the primary coil 151 based on the operating conditions of the internal combustion engine 100 and the dilution level of the air-fuel mixture. For example, as shown in FIG. 6(a), the ignition control unit 220 is provided with a map showing the relationship between the amount of current applied to the primary coil 151, the degree of dilution of the air-fuel mixture, and the rotational speed of the internal combustion engine 100. There is. The ignition control unit 220 sets the energization amount of the primary coil 151 used for the current energization based on the rotation speed of the internal combustion engine 100 and the degree of dilution of the air-fuel mixture, using the map shown in FIG. 6(a). Ignition control section 220 generates a primary coil energization signal according to the set amount of energization of primary coil 151 and outputs it to primary coil energization circuit 161 .
　また、点火制御部２２０は、内燃機関１００の運転条件及び混合気の希釈度に基づいて、３次コイル１５３の通電量を設定する。具体的には、点火制御部２２０には、図６（ｂ）に示すように、３次コイル１５３の通電量と混合気の希釈度と内燃機関１００の回転数との関係を示すマップが予め設けられている。点火制御部２２０は、図６（ｂ）に示すマップを用いて、内燃機関１００の回転数及び混合気の希釈度から、今回の通電に用いる３次コイル１５３の通電量を設定する。点火制御部２２０は、設定された３次コイル１５３の通電量に応じて３次コイル通電信号を生成し、３次コイル通電回路１６２に出力する。 Furthermore, the ignition control unit 220 sets the amount of current applied to the tertiary coil 153 based on the operating conditions of the internal combustion engine 100 and the dilution level of the air-fuel mixture. Specifically, as shown in FIG. 6(b), the ignition control unit 220 has a map in advance that shows the relationship between the amount of electricity supplied to the tertiary coil 153, the dilution level of the air-fuel mixture, and the rotational speed of the internal combustion engine 100. It is provided. The ignition control unit 220 uses the map shown in FIG. 6(b) to set the amount of energization of the tertiary coil 153 used for the current energization based on the rotation speed of the internal combustion engine 100 and the dilution of the air-fuel mixture. Ignition control section 220 generates a tertiary coil energization signal according to the set amount of energization of tertiary coil 153 and outputs it to tertiary coil energization circuit 162 .
　点火制御部２２０は、３次コイル１５３の通電量を設定するにあたり、図７（ａ）に示すように、推定されたコイル温度が高いほど３次コイル１５３の通電量が小さくなるように、３次コイル１５３の通電量を制御する。具体的には、点火制御部２２０は、推定されたコイル温度が高いほど３次コイル１５３の通電量が小さくなるように３次コイル１５３の通電量の上限値を設定する。そして、点火制御部２２０は、３次コイル１５３の通電量をこの上限値以下に設定してもよい。 When setting the energization amount of the tertiary coil 153, the ignition control unit 220 sets the energization amount of the tertiary coil 153 so that the higher the estimated coil temperature, the smaller the energization amount of the tertiary coil 153, as shown in FIG. The amount of current applied to the secondary coil 153 is controlled. Specifically, the ignition control unit 220 sets the upper limit value of the energization amount of the tertiary coil 153 such that the higher the estimated coil temperature, the smaller the energization amount of the tertiary coil 153. Then, the ignition control unit 220 may set the amount of current applied to the tertiary coil 153 to be equal to or less than this upper limit value.
　これにより、点火制御部２２０は、３次コイル１５３の通電量を、点火コイル１５０が発熱により故障しない通電量の範囲内に制限する（小さくする）ことができる。したがって、制御装置２００は、混合気の安定的燃焼に必要な点火プラグ１０５へのエネルギ供給量を確保しながら、点火コイル１５０の発熱による故障を防止することができる。 Thereby, the ignition control unit 220 can limit (reduce) the amount of current applied to the tertiary coil 153 within the range of the amount of current that does not cause the ignition coil 150 to malfunction due to heat generation. Therefore, the control device 200 can prevent failures due to heat generation in the ignition coil 150 while ensuring the amount of energy supplied to the spark plug 105 necessary for stable combustion of the air-fuel mixture.
　点火制御部２２０は、推定されたコイル温度が所定温度を超えた場合、図７（ａ）に示すように、３次コイル１５３の通電を停止する。所定温度は、点火コイル１５０が最も厳しい使用環境で使用されても点火コイル１５０が発熱により故障しない温度（例えば１５０℃）であってもよい。点火コイル１５０の最も厳しい使用環境とは、例えば、自動車の急加速後のように、エンジンルーム内に熱が籠った環境である。点火コイル１５０の最も厳しい使用環境において、エンジンルーム温度又は冷却水温度は、例えば１２０℃であってもよい。 When the estimated coil temperature exceeds a predetermined temperature, the ignition control unit 220 stops energizing the tertiary coil 153, as shown in FIG. 7(a). The predetermined temperature may be a temperature (for example, 150° C.) at which the ignition coil 150 will not fail due to heat generation even if the ignition coil 150 is used in the harshest usage environment. The harshest environment in which the ignition coil 150 is used is, for example, an environment where heat is trapped in the engine room, such as after rapid acceleration of a car. In the most severe usage environment of the ignition coil 150, the engine room temperature or the cooling water temperature may be, for example, 120°C.
　これにより、制御装置２００は、混合気の安定的燃焼に必要な点火プラグ１０５へのエネルギ供給量を確保しながら、点火コイル１５０の発熱による故障を確実に防止することができる。 Thereby, the control device 200 can reliably prevent failures due to heat generation in the ignition coil 150 while ensuring the amount of energy supplied to the spark plug 105 necessary for stable combustion of the air-fuel mixture.
　なお、点火制御部２２０は、コイル温度に応じて３次コイル１５３の通電量だけでなく、１次コイル１５１の通電量も制御することができる。例えば、図７（ｂ）に示すように、内燃機関１００の回転数が高い場合、点火プラグ１０５に大電流を供給することが要求されるので、１次コイル１５１の通電量を制限し難い。したがって、点火制御部２２０は、内燃機関１００の回転数が高い場合、１次コイル１５１の通電量よりも３次コイル１５３の通電量を優先して制限する（小さくする）。一方、内燃機関１００の回転数が低い場合、点火プラグ１０５の長放電が燃焼安定化に有効である。したがって、点火制御部２２０は、内燃機関１００の回転数が低い場合、３次コイル１５３の通電量よりも１次コイル１５１の通電量を優先して制限する（小さくする）。 Note that the ignition control unit 220 can control not only the amount of energization of the tertiary coil 153 but also the amount of energization of the primary coil 151 according to the coil temperature. For example, as shown in FIG. 7(b), when the rotational speed of the internal combustion engine 100 is high, a large current is required to be supplied to the spark plug 105, so it is difficult to limit the amount of current flowing through the primary coil 151. Therefore, when the rotational speed of the internal combustion engine 100 is high, the ignition control unit 220 prioritizes and limits (reduces) the amount of energization of the tertiary coil 153 over the amount of energization of the primary coil 151. On the other hand, when the rotational speed of the internal combustion engine 100 is low, the long discharge of the spark plug 105 is effective for stabilizing combustion. Therefore, when the rotational speed of the internal combustion engine 100 is low, the ignition control unit 220 prioritizes and limits (reduces) the amount of energization of the primary coil 151 over the amount of energization of the tertiary coil 153.
　これにより、制御装置２００は、内燃機関１００が様々な運転条件で運転する場合であっても、混合気の安定的燃焼に必要な点火プラグ１０５へのエネルギ供給量を確実且つ効率良く確保しながら、点火コイル１５０の発熱による故障を防止することができる。 As a result, even when the internal combustion engine 100 operates under various operating conditions, the control device 200 can reliably and efficiently secure the amount of energy supplied to the spark plug 105 necessary for stable combustion of the air-fuel mixture. , failure due to heat generation of the ignition coil 150 can be prevented.
　以上のように、実施形態１の制御装置２００は、点火プラグ１０５及び点火コイル１５０を備えた内燃機関１００の制御装置であって、点火コイル１５０の内部又は周囲の温度であるコイル温度を推定する温度推定部２１０と、点火コイル１５０の通電を制御することによって点火プラグ１０５に供給される電流を制御する点火制御部２２０と、を備える。点火コイル１５０は、点火プラグ１０５に電流を供給中に当該電流を増加させる増加機構を有する。点火制御部２２０は、推定されたコイル温度の温度が高いほど、増加機構による電流の増加量が小さくなるように当該増加量を制御する。 As described above, the control device 200 of the first embodiment is a control device for the internal combustion engine 100 that includes the spark plug 105 and the ignition coil 150, and estimates the coil temperature, which is the temperature inside or around the ignition coil 150. The ignition control unit 220 includes a temperature estimation unit 210 and an ignition control unit 220 that controls current supplied to the spark plug 105 by controlling energization of the ignition coil 150. The ignition coil 150 has an increasing mechanism that increases the current while supplying the current to the spark plug 105. The ignition control unit 220 controls the amount of increase in current due to the increase mechanism so that the higher the estimated coil temperature is, the smaller the amount of increase in current due to the increase mechanism becomes.
　これにより、実施形態１の制御装置２００は、増加機構による電流の増加量を、点火コイル１５０が発熱により故障しない通電量の範囲内に制限する（小さくする）ことができる。したがって、実施形態１の制御装置２００は、混合気の安定的燃焼に必要な点火プラグ１０５へのエネルギ供給量を確保しながら、点火コイル１５０の発熱による故障を防止することができる。よって、実施形態１の制御装置２００は、混合気の安定的燃焼と点火コイル１５０の発熱による故障防止との両立を図ることができる。 Thereby, the control device 200 of the first embodiment can limit (reduce) the amount of increase in current by the increasing mechanism to within the range of the amount of current that does not cause the ignition coil 150 to malfunction due to heat generation. Therefore, the control device 200 of the first embodiment can prevent failure due to heat generation of the ignition coil 150 while ensuring the amount of energy supplied to the spark plug 105 necessary for stable combustion of the air-fuel mixture. Therefore, the control device 200 of the first embodiment can achieve both stable combustion of the air-fuel mixture and prevention of failures due to heat generation of the ignition coil 150.
［実施形態２］
　図８～図１２を用いて、実施形態２の内燃機関１００の制御装置２００について説明する。実施形態２の内燃機関１００の制御装置２００において、実施形態１と同様の構成及び動作については、説明を省略する。 [Embodiment 2]
A control device 200 for an internal combustion engine 100 according to a second embodiment will be described using FIGS. 8 to 12. In the control device 200 for the internal combustion engine 100 according to the second embodiment, descriptions of the same configuration and operation as those in the first embodiment will be omitted.
　図８は、実施形態２の制御装置２００の機能的構成を示すブロック図である。図９（ａ）は、リターン信号の長さとコイル温度との関係を説明する図である。図９（ｂ）は、リターン信号の長さを説明する図である。図１０は、１次コイル１５１又は３次コイル１５３の通電量と、２次コイル１５２の発生電流（エネルギ）との関係を示すマップを説明する図である。図１１は、２次コイル１５２の発生電流（エネルギ）の上限値と、混合気のＥＧＲ率の目標値及び／又は空燃比の目標値との関係を示すマップを説明する図である。図１２は、温度特性診断部２５０を説明する図である。 FIG. 8 is a block diagram showing the functional configuration of the control device 200 of the second embodiment. FIG. 9(a) is a diagram illustrating the relationship between the length of the return signal and the coil temperature. FIG. 9(b) is a diagram illustrating the length of the return signal. FIG. 10 is a diagram illustrating a map showing the relationship between the energization amount of the primary coil 151 or the tertiary coil 153 and the current (energy) generated by the secondary coil 152. FIG. 11 is a diagram illustrating a map showing the relationship between the upper limit value of the current (energy) generated by the secondary coil 152 and the target value of the EGR rate and/or the target value of the air-fuel ratio of the air-fuel mixture. FIG. 12 is a diagram illustrating the temperature characteristic diagnosis section 250.
　実施形態２の制御装置２００は、温度推定部２１０と、点火制御部２２０と、発生電流推定部２３０と、希釈度設定部２４０と、温度特性診断部２５０と、を備える。なお、実施形態２の点火制御部２２０は、実施形態１と同様であるため、説明を省略する。 The control device 200 of the second embodiment includes a temperature estimation section 210, an ignition control section 220, a generated current estimation section 230, a dilution setting section 240, and a temperature characteristic diagnosis section 250. Note that the ignition control unit 220 of the second embodiment is the same as that of the first embodiment, so a description thereof will be omitted.
　実施形態２の温度推定部２１０は、点火コイル１５０の通電に応答して点火コイル１５０側から制御装置２００側に出力されるリターン信号に基づいて、コイル温度を推定する。リターン信号は、上記のように、３次コイル１５３の通電が停止すると、特に通電が異常停止すると、出力される。リターン信号は、点火コイル１５０の部品としての特性に起因して、その長さが変化する。リターン信号の長さは、図９（ａ）に示すように、コイル温度が高いほど長くなる。リターン信号の長さは、リターン信号自体の時間幅であってもよいが、図９（ｂ）に示すように、リターン信号及び３次コイル通電信号の時間幅であってもよい。すなわち、リターン信号の長さは、３次コイル通電信号の立ち上がりからリターン信号の立ち下がりまでの時間であってもよい。 The temperature estimation unit 210 of the second embodiment estimates the coil temperature based on a return signal output from the ignition coil 150 side to the control device 200 side in response to energization of the ignition coil 150. As described above, the return signal is output when the energization of the tertiary coil 153 stops, particularly when the energization stops abnormally. The length of the return signal varies depending on the characteristics of the ignition coil 150 as a component. As shown in FIG. 9(a), the length of the return signal increases as the coil temperature increases. The length of the return signal may be the time width of the return signal itself, or may be the time width of the return signal and the tertiary coil energization signal, as shown in FIG. 9(b). That is, the length of the return signal may be the time from the rise of the tertiary coil energization signal to the fall of the return signal.
　実施形態２の温度推定部２１０には、図９（ａ）に示すように、リターン信号の長さとコイル温度との関係を示すマップが予め設けられている。実施形態２の温度推定部２１０は、図９（ａ）に示すマップを用いて、リターン信号の長さからコイル温度を推定する。 As shown in FIG. 9(a), the temperature estimation unit 210 of the second embodiment is provided with a map showing the relationship between the length of the return signal and the coil temperature in advance. The temperature estimation unit 210 of the second embodiment estimates the coil temperature from the length of the return signal using the map shown in FIG. 9(a).
　これにより、実施形態２の温度推定部２１０は、点火コイル１５０の温度特性に合わせてコイル温度を推定することができるので、実施形態１よりもコイル温度の推定精度を向上させることができる。したがって、実施形態２の制御装置２００は、混合気の安定的燃焼に必要な点火プラグ１０５へのエネルギ供給量を確保しながら、点火コイル１５０の発熱による故障を更に確実に防止することができる。 Thereby, the temperature estimating unit 210 of the second embodiment can estimate the coil temperature in accordance with the temperature characteristics of the ignition coil 150, so that the accuracy of estimating the coil temperature can be improved compared to the first embodiment. Therefore, the control device 200 of the second embodiment can more reliably prevent failures due to heat generation in the ignition coil 150 while ensuring the amount of energy supplied to the spark plug 105 necessary for stable combustion of the air-fuel mixture.
　発生電流推定部２３０は、１次コイル１５１の通電量及び３次コイル１５３の通電量に基づいて、２次コイル１５２の発生電流（エネルギ）の上限値を推定する。具体的には、発生電流推定部２３０には、図１０に示すように、１次コイル１５１の通電量と２次コイル１５２の発生電流（エネルギ）との関係、及び、３次コイル１５３の通電量と２次コイル１５２の発生電流（エネルギ）との関係を示すマップが予め設けられている。発生電流推定部２３０は、図１０に示すマップを用いて、１次コイル１５１の通電量及び３次コイル１５３から、２次コイル１５２の発生電流（エネルギ）を特定する。そして、発生電流推定部２３０は、１次コイル１５１の通電による２次コイル１５２の発生電流（エネルギ）と３次コイル１５３の通電による２次コイル１５２の発生電流（エネルギ）との合計値と、変換効率とから、２次コイル１５２の発生電流（エネルギ）を計算する。そして、発生電流推定部２３０は、この計算値を、２次コイル１５２の発生電流（エネルギ）の上限値とすることができる。 The generated current estimation unit 230 estimates the upper limit value of the generated current (energy) of the secondary coil 152 based on the amount of energization of the primary coil 151 and the amount of energization of the tertiary coil 153. Specifically, as shown in FIG. 10, the generated current estimation unit 230 calculates the relationship between the amount of energization of the primary coil 151 and the generated current (energy) of the secondary coil 152, and the energization of the tertiary coil 153. A map showing the relationship between the amount and the current (energy) generated by the secondary coil 152 is provided in advance. The generated current estimating unit 230 specifies the generated current (energy) of the secondary coil 152 from the amount of energization of the primary coil 151 and the tertiary coil 153 using the map shown in FIG. The generated current estimation unit 230 calculates the total value of the current (energy) generated in the secondary coil 152 due to the energization of the primary coil 151 and the current (energy) generated in the secondary coil 152 due to the energization of the tertiary coil 153; The current (energy) generated by the secondary coil 152 is calculated from the conversion efficiency. The generated current estimation unit 230 can then use this calculated value as the upper limit value of the generated current (energy) of the secondary coil 152.
　希釈度設定部２４０は、発生電流推定部２３０により推定された２次コイル１５２の発生電流（エネルギ）の上限値に基づいて、内燃機関１００の気筒内に供給される混合気の希釈度の目標値を設定する。混合気の希釈度は、混合気のＥＧＲ率、及び／又は、混合気の空燃比である。発生電流推定部２３０には、図１１に示すように、２次コイル１５２の発生電流（エネルギ）の上限値と混合気のＥＧＲ率の目標値との関係、及び／又は、２次コイル１５２の発生電流（エネルギ）の上限値と空燃比の目標値との関係を示すマップが予め設けられている。希釈度設定部２４０は、図１１に示すマップを用いて、推定された２次コイル１５２の発生電流（エネルギ）の上限値から、混合気のＥＧＲ率の目標値及び/又は空燃比の目標値を設定する。 The dilution level setting unit 240 sets a target dilution level of the air-fuel mixture supplied into the cylinders of the internal combustion engine 100 based on the upper limit value of the generated current (energy) of the secondary coil 152 estimated by the generated current estimation unit 230. Set the value. The dilution degree of the mixture is the EGR rate of the mixture and/or the air-fuel ratio of the mixture. As shown in FIG. 11, the generated current estimating unit 230 includes the relationship between the upper limit value of the generated current (energy) of the secondary coil 152 and the target value of the EGR rate of the air-fuel mixture, and/or the relationship between the upper limit value of the generated current (energy) of the secondary coil 152 and the target value of the EGR rate of the A map showing the relationship between the upper limit value of the generated current (energy) and the target value of the air-fuel ratio is provided in advance. The dilution level setting unit 240 uses the map shown in FIG. 11 to determine the target value of the EGR rate and/or the target value of the air-fuel ratio of the air-fuel mixture from the estimated upper limit value of the current (energy) generated by the secondary coil 152. Set.
　すなわち、希釈度設定部２４０は、図１１に示すように、推定された２次コイル１５２の発生電流（エネルギ）の上限値が小さいと、混合気のＥＧＲ率の目標値及び／又は空燃比の目標値を小さくするという関係を用いて、混合気のＥＧＲ率の目標値及び／又は空燃比の目標値を設定する。 That is, as shown in FIG. 11, when the estimated upper limit of the current (energy) generated by the secondary coil 152 is small, the dilution setting unit 240 sets the target value of the EGR rate of the mixture and/or the air-fuel ratio. The target value of the EGR rate and/or the target value of the air-fuel ratio of the air-fuel mixture is set using the relationship of decreasing the target value.
　これにより、実施形態２の制御装置２００は、３次コイル１５３の通電量を制限すると（小さくすると）混合気の安定的燃焼に必要な点火プラグ１０５へのエネルギ供給量を確保できない場合には、ＥＧＲ率の目標値及び／又は空燃比の目標値を制御することによって、混合気を安定的に燃焼させることができる。よって、実施形態２の制御装置２００は、混合気の安定的燃焼と点火コイル１５０の発熱による故障防止との両立を図ることができる。なお、発生電流推定部２３０及び希釈度設定部２４０は、実施形態１の制御装置２００に備えられていてもよい。 As a result, in the case where the control device 200 of the second embodiment cannot secure the amount of energy supplied to the spark plug 105 necessary for stable combustion of the air-fuel mixture if the energization amount of the tertiary coil 153 is restricted (reduced), By controlling the target value of the EGR rate and/or the target value of the air-fuel ratio, the air-fuel mixture can be stably combusted. Therefore, the control device 200 of the second embodiment can achieve both stable combustion of the air-fuel mixture and prevention of failures due to heat generation of the ignition coil 150. Note that the generated current estimating section 230 and the dilution level setting section 240 may be included in the control device 200 of the first embodiment.
　温度特性診断部２５０は、コイル温度に応じてリターン信号の長さが変化する点火コイル１５０の温度特性を診断する。具体的には、温度特性診断部２５０は、外気温とコイル温度とが等しいと想定される時に、外気温とリターン信号の長さとを紐付けて予め収集している。外気温とコイル温度とが等しいと想定される時とは、例えば、内燃機関１００が長期間停止して冷却水温度と外気温とが同等となった内燃機関１００の始動直後のタイミングである。加えて、温度特性診断部２５０は、収集された外気温の中央値（又は平均値）とリターン信号の長さの中央値（又は平均値）との関係を、コイル温度の中央値（又は平均値）とリターン信号の長さの中央値（又は平均値）との関係と見做して、予め記憶している。コイル温度の中央値（又は平均値）とリターン信号の長さの中央値（又は平均値）との関係は、コイル温度が高くなるほどリターン信号の長さが長くなる関係であり、図１２の破線で示すような直線関係として表される。 The temperature characteristic diagnosis section 250 diagnoses the temperature characteristic of the ignition coil 150, in which the length of the return signal changes depending on the coil temperature. Specifically, when it is assumed that the outside temperature and the coil temperature are equal, the temperature characteristic diagnosis unit 250 collects in advance the outside temperature and the length of the return signal in association with each other. The time when the outside air temperature and the coil temperature are assumed to be equal is, for example, the timing immediately after the internal combustion engine 100 is started after the internal combustion engine 100 has stopped for a long time and the cooling water temperature and the outside air temperature have become equal. In addition, the temperature characteristic diagnosis unit 250 calculates the relationship between the median value (or average value) of the collected outside air temperature and the median value (or average value) of the length of the return signal based on the median value (or average value) of the coil temperature. value) and the median value (or average value) of the length of the return signal, and is stored in advance. The relationship between the median value (or average value) of the coil temperature and the median value (or average value) of the length of the return signal is such that the higher the coil temperature, the longer the length of the return signal. It is expressed as a linear relationship as shown in .
　そして、温度特性診断部２５０は、今回の診断において、外気温及びリターン信号の長さを取得すると、取得された外気温及びリターン信号の長さを通り、予め記憶された図１２に示す破線の傾きと同じ傾きの直線（図１２の実線）を特定する。温度特性診断部２５０は、特定された直線が示すコイル温度とリターン信号の長さとの関係を、今回の診断によって得られた点火コイル１５０の温度特性とする。 In the current diagnosis, when the temperature characteristic diagnosis unit 250 acquires the outside temperature and the length of the return signal, it passes through the acquired outside temperature and the length of the return signal and follows the dashed line shown in FIG. 12 stored in advance. A straight line with the same slope (solid line in FIG. 12) is identified. The temperature characteristic diagnosis unit 250 determines the relationship between the coil temperature indicated by the identified straight line and the length of the return signal as the temperature characteristic of the ignition coil 150 obtained by the current diagnosis.
　温度特性診断部２５０を備える制御装置２００の温度推定部２１０は、温度特性診断部２５０により今回の診断によって得られた温度特性に基づいて、コイル温度を推定することができる。 The temperature estimating unit 210 of the control device 200 including the temperature characteristic diagnosing unit 250 can estimate the coil temperature based on the temperature characteristics obtained by the current diagnosis by the temperature characteristic diagnosing unit 250.
　これにより、当該温度推定部２１０は、個々の点火コイル１５０によって異なる点火コイル１５０の温度特性を考慮してコイル温度を推定することができるので、コイル温度の推定精度を更に向上させることができる。したがって、温度特性診断部２５０を備える制御装置２００は、混合気の安定的燃焼に必要な点火プラグ１０５へのエネルギ供給量を確保しながら、点火コイル１５０の発熱による故障を更に確実に防止することができる。 Thereby, the temperature estimating unit 210 can estimate the coil temperature by taking into account the temperature characteristics of the ignition coil 150, which vary depending on the individual ignition coils 150, so that the accuracy of estimating the coil temperature can be further improved. Therefore, the control device 200 including the temperature characteristic diagnosis section 250 can more reliably prevent failures due to heat generation in the ignition coil 150 while ensuring the amount of energy supplied to the spark plug 105 necessary for stable combustion of the air-fuel mixture. Can be done.
　なお、上記の各実施形態では、リターン信号は、上記のように、３次コイル１５３の通電が停止すると出力される信号である。しかしながら、リターン信号は、１次コイル１５１の通電が停止すると出力される信号であってもよい。すなわち、リターン信号は、１次コイル１５１の通電に応答して１次コイル１５１側から制御装置２００側に出力される１次リターン信号と、３次コイル１５３の通電に応答して３次コイル１５３側から制御装置２００側に出力される３次リターン信号と、を含む。そして、温度推定部２１０は、１次リターン信号及び３次リターン信号の少なくとも１つに基づいて、コイル温度を推定することができる。 Note that in each of the above embodiments, the return signal is a signal that is output when the tertiary coil 153 is de-energized, as described above. However, the return signal may be a signal that is output when the primary coil 151 is de-energized. That is, the return signal includes a primary return signal outputted from the primary coil 151 side to the control device 200 side in response to energization of the primary coil 151, and a primary return signal outputted from the tertiary coil 153 side in response to energization of the tertiary coil 153. and a tertiary return signal output from the side to the control device 200 side. The temperature estimation unit 210 can estimate the coil temperature based on at least one of the primary return signal and the tertiary return signal.
　これにより、温度推定部２１０は、不測の事態により３次コイル１５３からの３次リターン信号が出力されない場合でも、１次コイル１５１からの１次リターン信号に基づいて、コイル温度を推定することができる。したがって、制御装置２００は、混合気の安定的燃焼に必要な点火プラグ１０５へのエネルギ供給量を確保しながら、点火コイル１５０の発熱による故障を確実且つ安定的に防止することができる。 Thereby, the temperature estimation unit 210 can estimate the coil temperature based on the primary return signal from the primary coil 151 even if the tertiary return signal is not output from the tertiary coil 153 due to an unexpected situation. can. Therefore, the control device 200 can reliably and stably prevent failures due to heat generation in the ignition coil 150 while ensuring the amount of energy supplied to the spark plug 105 necessary for stable combustion of the air-fuel mixture.
　また、上記の各実施形態では、リターン信号は、点火コイル１５０の通電が停止すると出力される信号としたが、リターン信号は、点火コイル１５０のコイル温度を検出する温度センサの検出信号であってもよい。温度推定部２１０は、リターン信号に基づいてコイル温度を推定する際、この温度センサの検出信号に基づいてコイル温度を推定することができる。 Further, in each of the above embodiments, the return signal is a signal that is output when the ignition coil 150 is de-energized, but the return signal is a detection signal of a temperature sensor that detects the coil temperature of the ignition coil 150. Good too. When estimating the coil temperature based on the return signal, the temperature estimation unit 210 can estimate the coil temperature based on the detection signal of this temperature sensor.
　これにより、温度推定部２１０は、正確なコイル温度を取得することができる。したがって、制御装置２００は、混合気の安定的燃焼に必要な点火プラグ１０５へのエネルギ供給量を確保しながら、点火コイル１５０の発熱による故障を更に確実に防止することができる。 Thereby, the temperature estimation unit 210 can obtain accurate coil temperature. Therefore, the control device 200 can more reliably prevent failures due to heat generation in the ignition coil 150 while ensuring the amount of energy supplied to the spark plug 105 necessary for stable combustion of the air-fuel mixture.
［その他］
　本発明は上記の実施形態に限定されるものではなく、様々な変形例が含まれる。例えば、上記の実施形態は本発明を分かりやすく説明するために詳細に説明したものであり、必ずしも説明した全ての構成を備えるものに限定されるものではない。また、或る実施形態の構成の一部を他の実施形態の構成に置き換えることが可能であり、また、或る実施形態の構成に他の実施形態の構成を加えることも可能である。また、各実施形態の構成の一部について、他の構成の追加・削除・置換をすることが可能である。 [others]
The present invention is not limited to the above-described embodiments, and includes various modifications. For example, the above embodiments have been described in detail to explain the present invention in an easy-to-understand manner, and the present invention is not necessarily limited to having all the configurations described. Furthermore, it is possible to replace a part of the configuration of one embodiment with the configuration of another embodiment, and it is also possible to add the configuration of another embodiment to the configuration of one embodiment. Furthermore, it is possible to add, delete, or replace some of the configurations of each embodiment with other configurations.
　また、上記の各構成、機能、処理部、処理手段等は、それらの一部又は全部を、例えば集積回路にて設計する等によりハードウェアによって実現してもよい。また、上記の各構成、機能等は、プロセッサがそれぞれの機能を実現するプログラムを解釈し、実行することによりソフトウェアによって実現してもよい。各機能を実現するプログラム、テープ、ファイル等の情報は、メモリや、ハードディスク、ＳＳＤ（solid state drive）等の記録装置、又は、ＩＣカード、ＳＤカード、ＤＶＤ等の記録媒体に置くことができる。 Further, each of the above-mentioned configurations, functions, processing units, processing means, etc. may be partially or entirely realized by hardware, for example, by designing an integrated circuit. Further, each of the above-mentioned configurations, functions, etc. may be realized by software by a processor interpreting and executing a program for realizing each function. Information such as programs, tapes, and files that implement each function can be stored in a memory, a recording device such as a hard disk, an SSD (solid state drive), or a recording medium such as an IC card, SD card, or DVD.
　また、制御線や情報線は説明上必要と考えられるものを示しており、製品上必ずしも全ての制御線や情報線を示しているとは限らない。実際には殆ど全ての構成が相互に接続されていると考えてもよい。 In addition, control lines and information lines are shown that are considered necessary for explanation, and not all control lines and information lines are necessarily shown in the product. In reality, almost all components may be considered to be interconnected.
　１００…内燃機関、１０５…点火プラグ、１５０…点火コイル、１５１…１次コイル、１５２…２次コイル、１５３…３次コイル（増加機構）、２００…制御装置、２１０…温度推定部、２２０…点火制御部、２３０…発生電流推定部、２４０…希釈度設定部、２５０…温度特性診断部 DESCRIPTION OF SYMBOLS 100... Internal combustion engine, 105... Spark plug, 150... Ignition coil, 151... Primary coil, 152... Secondary coil, 153... Tertiary coil (increase mechanism), 200... Control device, 210... Temperature estimation unit, 220... Ignition control section, 230... Generated current estimation section, 240... Dilution setting section, 250... Temperature characteristic diagnosis section

Claims (8)

  1. 　点火プラグ及び点火コイルを備えた内燃機関の制御装置であって、
    　前記点火コイルの内部又は周囲の温度であるコイル温度を推定する温度推定部と、
    　前記点火コイルの通電を制御することによって前記点火プラグに供給される電流を制御する点火制御部と、を備え、
    　前記点火コイルは、前記点火プラグに前記電流を供給中に当該電流を増加させる増加機構を有し、
    　前記点火制御部は、推定された前記コイル温度の温度が高いほど、前記増加機構による前記電流の増加量が小さくなるように前記増加量を制御する
    　ことを特徴とする内燃機関の制御装置。     A control device for an internal combustion engine equipped with a spark plug and an ignition coil,
    a temperature estimation unit that estimates a coil temperature that is the temperature inside or around the ignition coil;
    an ignition control unit that controls the current supplied to the spark plug by controlling energization of the ignition coil,
    The ignition coil has an increasing mechanism that increases the current while supplying the current to the ignition plug,
    The control device for an internal combustion engine, wherein the ignition control unit controls the amount of increase in the current by the increase mechanism so that the higher the estimated coil temperature is, the smaller the amount of increase in the current by the increase mechanism is.
  2. 　前記点火コイルは、１次側に配置された１次コイルと、２次側に配置され前記点火プラグに接続された２次コイルと、前記１次側に配置された３次コイルと、を有し、
    　前記増加機構は、前記３次コイルであり、
    　前記点火制御部は、前記１次コイルの通電によって前記点火プラグに前記電流を供給中、推定された前記コイル温度が高いほど前記３次コイルの通電量が小さくように、前記３次コイルの通電量を制御する
    　ことを特徴とする請求項１に記載の内燃機関の制御装置。     The ignition coil includes a primary coil placed on the primary side, a secondary coil placed on the secondary side and connected to the ignition plug, and a tertiary coil placed on the primary side. death,
    The increasing mechanism is the tertiary coil,
    While supplying the current to the spark plug by energizing the primary coil, the ignition control unit controls energization of the tertiary coil such that the higher the estimated coil temperature, the smaller the amount of energization of the tertiary coil. The control device for an internal combustion engine according to claim 1, wherein the control device controls the amount.
  3. 　前記温度推定部は、前記内燃機関の運転条件、前記内燃機関の冷却水温度、及び、前記点火コイルの通電量に基づいて、前記コイル温度を推定する
    　ことを特徴とする請求項２に記載の内燃機関の制御装置。     The temperature estimation unit estimates the coil temperature based on operating conditions of the internal combustion engine, a cooling water temperature of the internal combustion engine, and an amount of current flowing through the ignition coil. Internal combustion engine control device.
  4. 　前記温度推定部は、前記点火コイルの通電に応答して前記点火コイル側から前記制御装置側に出力されるリターン信号に基づいて、前記コイル温度を推定する
    　ことを特徴とする請求項２に記載の内燃機関の制御装置。     The temperature estimator estimates the coil temperature based on a return signal output from the ignition coil to the control device in response to energization of the ignition coil. Control equipment for internal combustion engines.
  5. 　前記点火制御部は、推定された前記コイル温度が所定温度を超えた場合、前記３次コイルの通電を停止する
    　ことを特徴とする請求項２に記載の内燃機関の制御装置。     The control device for an internal combustion engine according to claim 2, wherein the ignition control unit stops energization of the tertiary coil when the estimated coil temperature exceeds a predetermined temperature.
  6. 　前記１次コイルの通電量及び前記３次コイルの通電量に基づいて、前記２次コイルの発生電流の上限値を推定する発生電流推定部と、
    　推定された前記発生電流の上限値に基づいて、前記内燃機関の気筒内に供給される混合気の希釈度の目標値を設定する希釈度設定部と、を更に備える
    　ことを特徴とする請求項２に記載の内燃機関の制御装置。     a generated current estimation unit that estimates an upper limit value of the generated current of the secondary coil based on the amount of energization of the primary coil and the amount of energization of the tertiary coil;
    Claim further comprising: a dilution level setting unit that sets a target value for the dilution level of the air-fuel mixture supplied into the cylinders of the internal combustion engine based on the estimated upper limit value of the generated current. 2. The control device for an internal combustion engine according to 2.
  7. 　前記コイル温度に応じて前記リターン信号の長さが変化する前記点火コイルの温度特性を診断する温度特性診断部を更に備え、
    　前記温度推定部は、診断された前記温度特性に基づいて、前記コイル温度を推定する
    　ことを特徴とする請求項４に記載の内燃機関の制御装置。     further comprising a temperature characteristic diagnosis unit that diagnoses a temperature characteristic of the ignition coil in which the length of the return signal changes depending on the coil temperature;
    The control device for an internal combustion engine according to claim 4, wherein the temperature estimation unit estimates the coil temperature based on the diagnosed temperature characteristic.
  8. 　前記リターン信号は、前記１次コイルの通電に応答して前記１次コイル側から前記制御装置側に出力される１次リターン信号と、前記３次コイルの通電に応答して前記３次コイル側から前記制御装置側に出力される３次リターン信号と、を含み、
    　前記温度推定部は、前記１次リターン信号及び前記３次リターン信号の少なくとも１つに基づいて、前記コイル温度を推定する
    　ことを特徴とする請求項４に記載の内燃機関の制御装置。     The return signal includes a primary return signal outputted from the primary coil side to the control device side in response to energization of the primary coil, and a primary return signal outputted from the tertiary coil side in response to energization of the tertiary coil. a tertiary return signal output from the controller to the control device,
    The control device for an internal combustion engine according to claim 4, wherein the temperature estimator estimates the coil temperature based on at least one of the primary return signal and the tertiary return signal.
PCT/JP2022/028271 2022-07-20 2022-07-20 Internal combustion engine control device WO2024018575A1 (en)

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Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2015194125A (en) * 2014-03-31 2015-11-05 ダイハツ工業株式会社 Internal combustion engine control device
WO2016157543A1 (en) * 2015-04-01 2016-10-06 日立オートモティブシステムズ阪神株式会社 Ignition device for internal combustion engine
JP2017207007A (en) * 2016-05-18 2017-11-24 トヨタ自動車株式会社 Ignition control device
JP2019203488A (en) * 2018-05-25 2019-11-28 株式会社デンソー Ignition device of internal combustion engine

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2015194125A (en) * 2014-03-31 2015-11-05 ダイハツ工業株式会社 Internal combustion engine control device
WO2016157543A1 (en) * 2015-04-01 2016-10-06 日立オートモティブシステムズ阪神株式会社 Ignition device for internal combustion engine
JP2017207007A (en) * 2016-05-18 2017-11-24 トヨタ自動車株式会社 Ignition control device
JP2019203488A (en) * 2018-05-25 2019-11-28 株式会社デンソー Ignition device of internal combustion engine

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