WO2022269976A1 - Internal combustion engine control device - Google Patents

Internal combustion engine control device Download PDF

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Publication number
WO2022269976A1
WO2022269976A1 PCT/JP2022/003976 JP2022003976W WO2022269976A1 WO 2022269976 A1 WO2022269976 A1 WO 2022269976A1 JP 2022003976 W JP2022003976 W JP 2022003976W WO 2022269976 A1 WO2022269976 A1 WO 2022269976A1
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WO
WIPO (PCT)
Prior art keywords
internal combustion
combustion engine
ignition
flow velocity
timing
Prior art date
Application number
PCT/JP2022/003976
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French (fr)
Japanese (ja)
Inventor
一浩 押領司
好彦 赤城
貴和 松下
Original Assignee
日立Astemo株式会社
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
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Application filed by 日立Astemo株式会社 filed Critical 日立Astemo株式会社
Priority to JP2023529470A priority Critical patent/JPWO2022269976A1/ja
Priority to DE112022001358.3T priority patent/DE112022001358T5/en
Publication of WO2022269976A1 publication Critical patent/WO2022269976A1/en

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    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
    • F02D—CONTROLLING COMBUSTION ENGINES
    • F02D43/00—Conjoint electrical control of two or more functions, e.g. ignition, fuel-air mixture, recirculation, supercharging or exhaust-gas treatment
    • F02D43/04—Conjoint electrical control of two or more functions, e.g. ignition, fuel-air mixture, recirculation, supercharging or exhaust-gas treatment using only digital means
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
    • F02D—CONTROLLING COMBUSTION ENGINES
    • F02D41/00—Electrical control of supply of combustible mixture or its constituents
    • F02D41/0002—Controlling intake air
    • F02D41/0007—Controlling intake air for control of turbo-charged or super-charged engines
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
    • F02D—CONTROLLING COMBUSTION ENGINES
    • F02D41/00—Electrical control of supply of combustible mixture or its constituents
    • F02D41/30—Controlling fuel injection
    • F02D41/38—Controlling fuel injection of the high pressure type
    • F02D41/40—Controlling fuel injection of the high pressure type with means for controlling injection timing or duration
    • 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
    • F02P15/00—Electric spark ignition having characteristics not provided for in, or of interest apart from, groups F02P1/00 - F02P13/00 and combined with layout of ignition circuits
    • F02P15/08—Electric spark ignition having characteristics not provided for in, or of interest apart from, groups F02P1/00 - F02P13/00 and combined with layout of ignition circuits having multiple-spark ignition, i.e. ignition occurring simultaneously at different places in one engine cylinder or in two or more separate engine cylinders
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
    • F02D—CONTROLLING COMBUSTION ENGINES
    • F02D41/00—Electrical control of supply of combustible mixture or its constituents
    • F02D41/0002—Controlling intake air
    • F02D2041/0015—Controlling intake air for engines with means for controlling swirl or tumble flow, e.g. by using swirl valves
    • 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
    • F02P9/00—Electric spark ignition control, not otherwise provided for
    • F02P9/002—Control of spark intensity, intensifying, lengthening, suppression

Definitions

  • the present invention relates to a control device for an internal combustion engine.
  • the intake pipe pressure can be increased compared to when dilution combustion is not used, so it is possible to reduce the pump loss under low load conditions of the internal combustion engine.
  • the heat capacity when burning the same amount of fuel can be increased, so the combustion temperature of the air-fuel mixture can be lowered and the cooling loss can be reduced.
  • the occurrence of abnormal combustion can be suppressed by suppressing the reaction progress leading to the self-ignition reaction due to the introduction of the EGR gas.
  • the ignition timing can be advanced so as to approach the optimum timing, so that the exhaust loss can be reduced.
  • the degree of dilution of the air-fuel mixture is the ratio of the mass sum of the mixed gas consisting of air and EGR gas to the fuel mass (gas-fuel ratio G/F), the air-to-fuel mass ratio (air-fuel ratio A/F), the intake gas EGR ratio (EGR rate) is often evaluated.
  • the relative concentration of the fuel is low, so the air-fuel mixture in the cylinder is released from the spark plug during spark ignition. It is necessary to increase the amount of discharge energy supplied to the Further, the flow velocity of the air-fuel mixture around the plug at the ignition timing is a factor that affects the amount of discharge energy to be supplied. For example, it is well known that if the flow velocity of the air-fuel mixture around the plug at the ignition timing is high, the discharge will blow out, leading to misfiring.
  • Patent Document 1 proposes changing how to give the discharge current waveform according to the flow velocity in the cylinder. Specifically, in the discharge current waveform, when providing a period during which the current value is maintained at a predetermined value, an ignition device is proposed in which the rate of change from the initial value to the predetermined value is set according to the flow velocity.
  • Patent Document 1 when the predetermined value to be maintained is large with respect to the initial current, by setting the rate of change from the initial value to the predetermined value according to the flow velocity, the spark discharge is prevented from blowing out, Wasteful energy supply can be suppressed while achieving reliable ignition. However, Patent Document 1 does not consider wear of the spark plug.
  • An object of the present invention is to provide a control device for an internal combustion engine that can suppress wear of spark plugs while suppressing ignition failure of the internal combustion engine.
  • the control apparatus for an internal combustion engine of the present invention provides a target energy required for ignition of an air-fuel mixture in a cylinder of the internal combustion engine based on the operating conditions of the internal combustion engine and the dilution state of the air-fuel mixture.
  • a target ignition total energy indicating a value is calculated, and based on the parameter of the internal combustion engine that has a correlation with the flow velocity of the air-fuel mixture in the cylinder of the internal combustion engine at the ignition timing, the ignition device is caused to assist the discharge current, and the ignition
  • the device includes a processor for generating ignition energy corresponding to the target ignition total energy.
  • FIG. 1 is a configuration diagram showing a system configuration of an internal combustion engine;
  • FIG. It is a block diagram of an ignition coil. It is a figure explaining the electric current which generate
  • 1 is a configuration diagram of a control device for an internal combustion engine to which the present invention is applied;
  • FIG. It is a control block diagram of an embodiment of the present invention.
  • 4 is a control flow chart for explaining control steps executed by a control block according to an embodiment of the present invention;
  • FIG. 4 is a characteristic diagram showing the relationship between equivalence ratio and reference energy;
  • FIG. 4 is a characteristic diagram showing the relationship between an EGR rate and a correction coefficient;
  • FIG. 5 is a characteristic diagram showing the relationship between ignition timing pressure and correction coefficient;
  • FIG. 5 is a characteristic diagram showing the relationship between ignition timing temperature and correction coefficient;
  • FIG. 4 is a characteristic diagram showing the relationship between operating conditions and reference flow velocity;
  • FIG. 4 is a characteristic diagram showing the relationship between a variable valve and a correction coefficient;
  • FIG. 4 is a characteristic diagram showing the relationship between a tumble control valve and a correction coefficient;
  • FIG. 4 is a characteristic diagram showing the relationship between ignition timing and correction coefficient;
  • FIG. 5 is a characteristic diagram showing the relationship between the primary energization period and the current assist timing after the start of discharge according to the flow velocity for each target ignition total energy.
  • FIG. 4 is a characteristic diagram showing a current waveform that is realized;
  • 4 is a timing chart showing states of various actuators when the number of revolutions changes.
  • 4 is a timing chart showing states of various actuators when a variable valve operation amount changes; 4 is a timing chart showing the states of various actuators when the tumble control valve and throttle valve opening are changed. 4 is a timing chart showing states of various actuators when ignition timing is changed; 4 is a control flow chart for explaining control steps executed by a control block according to an embodiment of the present invention; 4 is a timing chart showing target values and actual values of dilution when the battery voltage changes. It is a control block diagram of the 2nd Embodiment of this invention. 4 is a control flow chart for explaining control steps executed by a control block according to an embodiment of the present invention; FIG. 10 is a characteristic diagram showing the relationship between operating conditions and a period (assist delay) until reference assist. FIG.
  • FIG. 4 is a characteristic diagram showing the relationship between a variable valve and a correction coefficient
  • FIG. 4 is a characteristic diagram showing the relationship between the degree of opening of a tumble control valve and a correction coefficient
  • FIG. 4 is a characteristic diagram showing the relationship between ignition timing and correction coefficient
  • Embodiments of the present invention relate to a control device for an internal combustion engine, and particularly to a control device for an internal combustion engine that is used in a spark ignition type internal combustion engine that uses an ignition coil to generate spark discharge in a spark plug to ignite an air-fuel mixture. It is about.
  • the purpose of the embodiments of the present invention is to provide a mechanism in which the discharge current can be added to the basic current waveform at arbitrary timing.
  • FIG. 1 shows the system configuration of a spark ignition type internal combustion engine used in automobiles, and includes an in-cylinder fuel injection device 13 that directly injects gasoline fuel into the cylinder.
  • the internal combustion engine ENG is an in-cylinder injection internal combustion engine for automobiles that performs spark ignition combustion.
  • An air flow sensor 1 for measuring the intake air amount and intake air temperature
  • a supercharger compressor 4a for supercharging the intake air
  • an intercooler 7 for cooling the intake air
  • an electronically controlled throttle 2 for adjusting the intake pipe pressure.
  • a humidity sensor (not shown) and a tumble control valve are provided at appropriate positions in each of the intake pipes.
  • the humidity sensor is a sensor that can detect relative humidity and absolute humidity.
  • a fuel injection device 13 injector for injecting fuel into the cylinder 14 of each cylinder and an ignition device (hereinafter referred to as ignition coil 16 and spark plug 17) for supplying ignition energy are provided for each cylinder. provided for.
  • the cylinder head is provided with a variable valve 5 that adjusts the air-fuel mixture flowing into the cylinder or the exhaust gas discharged from the cylinder.
  • a variable valve 5 that adjusts the air-fuel mixture flowing into the cylinder or the exhaust gas discharged from the cylinder.
  • a high-pressure fuel pump (not shown) for supplying high-pressure fuel to the fuel injection device 13 is connected to the fuel injection device 13 through a fuel pipe.
  • a fuel pressure sensor is provided.
  • a crank angle sensor 19 is attached to detect the position of the piston of the internal combustion engine. Output information from the crank angle sensor 19 is sent to an ECU 20 (Engine Control Unit).
  • a turbine 4b for applying rotational force to the compressor 4a of the supercharger by exhaust energy
  • an electronically controlled wastegate valve 11 for adjusting the flow rate of exhaust gas flowing to the turbine 4b
  • a three-way catalyst 10 for purifying the exhaust gas.
  • An air-fuel ratio sensor 9 for detecting the air-fuel ratio of the exhaust gas on the upstream side of the three-way catalyst 10 is provided at an appropriate position in each of the exhaust pipes 15 .
  • a water temperature sensor 18 is provided to measure the temperature of cooling water that flows around the internal combustion engine.
  • an EGR pipe is provided for recirculating exhaust gas from the exhaust pipe 15 downstream of the three-way catalyst 10 to the intake pipe upstream of the compressor 4a. EGR valves (EGR mechanism) for controlling the EGR flow rate are attached to the EGR pipes at appropriate positions.
  • the output information obtained from the airflow sensor 1, the water temperature sensor 18 and the air-fuel ratio sensor 9 is sent to the control unit (ECU 20) that controls the internal combustion engine. Further, output information obtained from the accelerator opening sensor 12 is sent to the ECU 20 .
  • the accelerator opening sensor 12 detects the depression amount of the accelerator pedal, that is, the accelerator opening.
  • the ECU 20 calculates the required torque based on the output information from the accelerator opening sensor 12 . That is, the accelerator opening sensor 12 is used as a required torque detection sensor that detects the required torque to the internal combustion engine.
  • the ECU 20 also calculates the rotation speed of the internal combustion engine based on output information from the crank angle sensor 19 .
  • the ECU 20 optimally calculates main operating variables of the internal combustion engine, such as air flow rate, fuel injection amount, ignition timing, and fuel pressure, based on the operating conditions of the internal combustion engine obtained from the output information of the various sensors.
  • the fuel injection amount calculated by the ECU 20 is converted into a valve opening pulse signal and sent to the fuel injection device 13 . Also, an ignition signal is sent to the ignition coil 16 so that the engine is ignited at the ignition timing calculated by the ECU 20 . Further, the throttle opening (also referred to as throttle valve opening) calculated by the ECU 20 is sent to the electronically controlled throttle 2 as a throttle drive signal.
  • Fuel is injected into the air that has flowed into the cylinder 14 from the intake pipe through the intake valve to form an air-fuel mixture.
  • the air-fuel mixture is exploded by a spark generated from the ignition plug 17 at a predetermined ignition timing, and the combustion pressure pushes down the piston to provide driving force for the internal combustion engine.
  • the exhaust gas after the explosion passes through the exhaust pipe 15 and is sent to the three-way catalyst 10, and the exhaust components are purified in the three-way catalyst 10 and discharged to the outside.
  • the ignition coil 16 is composed of a primary coil on the low voltage side (battery side) and a secondary coil on the high voltage side, and is designed to generate high voltage. In addition to these two coils, an ignition coil 16 having a tertiary coil that enables current assist on the low voltage side is applied.
  • 2A and 2B show a configuration example of the coil applied in this embodiment and the discharge current generated when the same coil is used. 2A and 2B, a specific circuit for energizing the ignition coil 16 is not shown.
  • FIG. 2A shows the configuration of the ignition coil 16
  • FIG. 2B shows the time history of the discharge current, the energized state of the primary coil, which is the manipulated variable, and the energized state of the tertiary coil.
  • the energized state is an index that indicates a state in which energization is being performed by ON, and a state in which energization is not being performed by OFF.
  • a discharge current begins to flow on the high voltage side.
  • the tertiary coil is not energized, the magnetic energy accumulated in the secondary coil is released, and the discharge current gradually decreases.
  • FIG. 3 is a configuration diagram showing the configuration of an internal combustion engine control device to which the present invention is applied.
  • Input signals such as air amount information from the air flow sensor 1, accelerator depression information from the accelerator opening sensor 12, and angle information from the crank angle sensor 19 are input to an input circuit 21 of the ECU 20, which is a control unit.
  • the input signals are not limited to these, additional description will be given as appropriate.
  • the input signal of each sensor is sent to the input port within the input/output port 22 .
  • the input information sent to the input port is temporarily stored in the RAM 23c and processed by the CPU 23a according to a predetermined control program.
  • a control program describing the contents of arithmetic processing is written in the ROM 23b in advance.
  • Output information indicating the amount of operation of the fuel injection device 13 and the ignition coil 16 for controlling the internal combustion engine calculated according to the control program is temporarily stored in the RAM 23c and then sent to the output port in the input/output port 22. It is sent to the fuel injection device 13 and the ignition coil 16 through the respective drive circuits.
  • other actuators are also used in internal combustion engines, their description is omitted here.
  • the ignition control section 24 is shown as the drive circuit, and the ignition control section 24 controls the timing of energizing the ignition coil 16, the amount of discharge energy, and the like.
  • the ECU 20 is provided with an ignition control section 24 for controlling the energization time of the ignition coil 16 and the amount of discharge energy.
  • the entire ignition control unit 24 may be mounted in a device separate from the ECU 20.
  • the ECU 20 calculates the discharge energy of the spark plug 17 according to the detected air amount, crank angle, cooling water temperature, intake air temperature, humidity, etc., and discharges the energy to the ignition coil 16 at an appropriate timing (conduction time or ignition timing). When energized, the air-fuel mixture in the cylinder is ignited.
  • FIG. 4 is a control block showing an outline of the discharge energy control performed by the ignition control section 24 in the ECU 20, which is the control device for the internal combustion engine of the embodiment of the present invention.
  • a target ignition total energy calculation unit 41 calculates a target ignition total energy amount based on the required torque calculated from the output information of the accelerator opening sensor 12 and the rotational speed of the internal combustion engine calculated from the output information of the crank angle sensor 19. It has a function to calculate The target ignition total energy amount calculated by the target ignition total energy calculation section 41 is input to the next-stage target ignition energy realization section 43 .
  • the ignition timing flow velocity calculation unit 42 has a function of calculating the plug peripheral flow velocity at the ignition timing based on the required torque, the rotational speed, the operation amount of the variable valve, the tumble control valve, and the ignition timing.
  • the plug-periphery flow velocity at the ignition timing calculated by the ignition timing flow velocity calculator 42 is also input to the next-stage target ignition energy realization section 43 .
  • the target ignition energy realization unit 43 determines the operation amount of the ignition device based on the target ignition total energy amount and the flow velocity around the plug at the ignition timing.
  • the target ignition energy realization unit 43 sets, calculates, and outputs the energization period of the primary coil that determines the basic current waveform, the timing of the assist, and the period.
  • the manipulated variable correction unit 44 is a block that determines whether or not the amount of energy that can be generated by the ignition device can be realized, and corrects the degree of dilution of the air-fuel mixture that affects the target energy and the manipulated variable of the actuator that affects the flow velocity.
  • the maximum generateable energy calculator 44 a calculates the maximum energy that can be generated based on the power supply voltage of the ignition coil 16 .
  • the calculated maximum energy is input to the target dilution correction section 44b.
  • the target dilution correction unit 44b calculates a dilution that can be achieved with the same maximum generateable energy, and based on the calculated dilution that can be achieved, sets a new air-fuel ratio target value (target air-fuel ratio) and an EGR rate target. (Target EGR rate) is calculated.
  • FIG. 5 shows a control flow of arithmetic processing for ignition control in the first embodiment.
  • Step S501 is a process executed by the target ignition total energy calculator 41 in FIG. 4
  • step S502 is a process executed by the ignition timing flow velocity calculator 42.
  • step S503 is a process executed by the target ignition energy realization section 43 .
  • a target ignition total energy is calculated.
  • the target ignition total energy is, for example, a reference energy calculated based on the equivalence ratio of the air-fuel mixture, a correction coefficient for correcting the energy amount according to the EGR rate, and a correction coefficient for correcting the energy amount according to the ignition timing pressure. , and a correction coefficient for correcting the amount of energy according to the temperature of the ignition timing.
  • the energy required for ignition is minimized in a specific equivalence ratio range.
  • the specific equivalence ratio range varies depending on the fuel type and oxidant type, but in the case of gasoline, it is minimized under conditions close to the stoichiometric mixture ratio (stoichiometry). Therefore, the reference energy has a downwardly convex characteristic with respect to the equivalence ratio (FIG. 6A).
  • the target ignition total energy can be calculated in step S501 of FIG.
  • a laminar combustion velocity as an index having characteristics opposite to the relationship between the equivalence ratio and the reference energy and the relationship between the EGR rate, pressure, temperature and the reference energy.
  • SL is the laminar combustion speed of the air-fuel mixture determined based on the ignition timing temperature, pressure, equivalence ratio, and EGR rate, and SL0 is the laminar combustion speed under the reference condition.
  • the laminar burning velocity SL may be obtained in advance through experiments, or may be obtained using an existing proposed formula. Since the laminar combustion velocity term in equation (1) is multiplied by a negative value, the target ignition total energy E calculated by equation (1) is the EGR rate, which has a minimum value for a specific equivalence ratio. It has a positive correlation with pressure, a positive correlation with pressure, and a negative correlation with temperature.
  • step S501 It is possible to calculate the target ignition total energy in step S501 by the method described above. By setting the target ignition total energy in this way, it is possible to set an appropriate energy target value based on parameters that affect ignitability, such as the equivalence ratio, EGR rate, ignition timing pressure, and ignition timing temperature.
  • step S502 the flow velocity around the spark plug at the ignition timing is calculated.
  • the flow velocity around the plug at the ignition timing depends on the operating conditions of the engine (engine torque, rotation speed), the variable valve operation amount and tumble control valve opening, which are the operation amounts of the actuators related to air flow, and the ignition timing, which is the ignition timing. Depends on the time.
  • FIGS. 7A to 7D show a relationship 71 between the operating conditions and the reference flow velocity, a relationship 72 between the variable valve operation amount and the correction coefficient, a relationship 73 between the tumble control valve opening and the correction coefficient, and a relationship 74 between the ignition timing and the correction coefficient, respectively.
  • the operating conditions include the rotational speed of the engine and the torque generated by the engine (engine torque).
  • engine torque The angular velocity of the vortex formed inside the engine tends to change according to the engine rotation speed, and the higher the engine rotation speed, the higher the ignition timing flow velocity (there is a positive correlation between the rotation speed and the flow velocity). be).
  • the greater the engine torque the more air is introduced into the engine cylinder, which increases the momentum in the engine cylinder and may increase the flow velocity (there is a positive correlation between throttle opening and flow velocity). be).
  • the correction coefficient has a characteristic of having a maximum value in the predetermined range of the operation amount of the variable valve (flow velocity).
  • flow velocity The greater the difference between the actual operation amount and the operation amount (reference operation amount) of the variable valve mechanism that maximizes the flow velocity, the smaller the flow velocity.There is a negative correlation between the difference between the reference operation amount and the actual operation amount and the flow velocity).
  • variable valve when the variable valve is operated to close the intake valve extremely early, the flow in the engine cylinder is attenuated and the flow velocity at the ignition timing becomes smaller. On the other hand, if the closing timing of the intake valve is extremely late, part of the air introduced into the engine cylinder will blow back into the intake pipe, reducing the momentum in the engine cylinder and reducing the flow velocity at the ignition timing. .
  • the change in flow velocity with respect to the operation amount of the variable valve has a characteristic that has a maximum value within a predetermined range (Fig. 7B).
  • the tumble control valve is a mechanism that increases the flow rate of gas flowing into the engine by closing part of the flow path by operating the control valve.
  • a large degree of opening of the tumble control valve indicates that the flow path is blocked by a relatively small amount.
  • the opening of the tumble control valve is large, the amount that blocks the flow path is relatively small, and the flow velocity at the ignition timing becomes small. large, and the flow velocity at the ignition timing becomes large.
  • the correction coefficient has a negative correlation with the degree of opening of the tumble control valve (Fig. 7C).
  • the radius of the vortex gradually decreases as the piston rises, and the flow velocity around the plug tends to decrease. Therefore, the correction coefficient increases as the ignition timing advances (Fig. 7D).
  • a correction map based on this is set so that the correction coefficient increases as the ignition timing is advanced.
  • the flow velocity around the spark plug at the ignition timing can be calculated in step S502.
  • Vadv is the cylinder internal volume (m 3 ) at the ignition timing
  • RT is the tumble vortex diameter (m)
  • Ne is the engine speed (rpm)
  • NT is the tumble ratio
  • ⁇ is the circumference ratio.
  • the tumble ratio is a characteristic of the engine, calculated in advance through simulations and experiments, and mapped or functioned. By mapping the tumble ratio according to the state of the tumble control valve, the influence of the tumble ratio can be reflected. Equation (3) can express differences in engine rotation speed and ignition timing, but cannot express the effects of engine torque and variable valve operation amount. In order to express these, the flow velocity can be calculated by obtaining the product of the correction coefficient calculated from the map of the relationship between the variable valve and the correction amount shown in FIGS. 7A to 7D.
  • Step S503 Based on the target ignition total energy E and the flow velocity V, the energization time of the primary coil and the assist timing are calculated. For example, the relationship between the energization time of the primary coil and the assist timing can be determined in advance according to the level of the target ignition total energy, and can be set based on the determined relationship.
  • FIGS. 8A and 8B show the relationship between the energization time of the primary coil and the assist timing according to the target ignition total energy and the flow velocity.
  • FIGS. 8A and 8B show a case where the target total energy is large, a case where the target total energy is medium, and a case where the target total energy is small.
  • the setting is based on the assumption that the target ignition total energy cannot be generated without ignition assistance.
  • the target ignition total energy is moderate, it is assumed that the target ignition total energy can be achieved within the setting range of the energization time of the primary coil, regardless of the flow velocity conditions.
  • the target ignition total energy is small, the range that can be realized by shortening the energization time of the primary coil is assumed under the condition where the flow velocity condition is small.
  • the assist timing is changed according to the flow velocity.
  • the energization time of the primary coil is set substantially constant regardless of the flow velocity conditions, and is set so that the greater the flow velocity, the earlier the ignition assist timing.
  • the discharge path expands slowly, the discharge path expands more, and the timing at which the reformation is likely to occur is delayed.
  • the reformation of the discharge path can be prevented, heating can be continued, and the target ignition total energy can be supplied to the flame.
  • the primary energization period is set larger as the flow velocity increases.
  • the assist is performed under the condition that the flow velocity is small, and the assist timing is advanced as the flow velocity increases.
  • FIG. 9 shows an example of the results of the above processing. From the top, the engine speed, flow rate at ignition timing, primary coil energization period, assist timing (tertiary coil energization start timing), and current waveform realized by the primary coil energization period and current assist are shown. In FIG. 9, the engine speed increases with the passage of time, and the figure shows the results at four levels of speed.
  • the rotation speed levels are shown as 1st level, 2nd level, 3rd level, and 4th level.
  • the primary coil energization period is increased compared to the first level, and the maximum current of the current waveform is increased.
  • the tertiary coil is energized.
  • the energization timing of the tertiary coil is earlier than when the rotational speed is at the third level.
  • FIG. 10 shows an example of the results of the above processing. From the top, the variable valve operation amount, the flow rate of the ignition timing, the primary coil energization period, the assist timing (tertiary coil energization start timing), and the current waveform realized by the primary coil energization period and current assist are shown.
  • the operation amount of the variable valve is operated from the advance side to the retard side with the passage of time, and the figure shows the results for four levels of the variable valve operation amount.
  • the levels of the variable valve operation amount are shown as 1st level, 2nd level, 3rd level, and 4th level.
  • the flow velocity increases, and in the change from the 3rd level to the 4th level, the flow velocity decreases.
  • the flow velocity does not necessarily change monotonically with respect to the amount of operation of the variable valve, so the change is as shown in FIG.
  • the change in the ignition assist timing may not change monotonically with respect to the operation amount of the same operation.
  • the necessary energy can be generated at an appropriate timing according to the flow velocity, ensuring ignitability and reducing waste. Suppression of energy supply can be realized.
  • FIG. 11 shows an example of the results of the processing described above. From the top, the tumble control valve operation amount, throttle opening, ignition timing flow rate, primary coil energization period, assist timing (tertiary coil energization start timing), and current waveform realized by primary coil energization period and current assist show.
  • the operation amount of the tumble control valve alternates between the open state and the closed state as time elapses.
  • the throttle opening is maintained at a constant opening, and in the second half (3rd and 4th levels) , the throttle opening is large.
  • variable valve operation amount of the variable valve is being operated from the advance side to the retard side, and the figure shows the results for four levels of variable valve operation amounts. Comparing the flow velocity when the tumble control valve is open and closed under the same throttle opening conditions, the flow velocity is large when the tumble control valve is closed. High velocity.
  • the flow velocity is higher when the tumble control valve is closed than when the tumble control valve is open, so the assist timing is earlier. Also, under conditions where the throttle opening is large, the flow velocity is greater than under conditions where the throttle opening is small, so the assist timing is set to be earlier.
  • FIG. 12 shows an example of the results of the above processing. From the top, the ignition timing, the flow rate at the ignition timing, the primary coil energization period, the assist timing (tertiary coil energization start timing), and the current waveform realized by the primary coil energization period and current assist are shown.
  • the ignition timing changes in the advance direction with the lapse of time. The flow velocity increases as the ignition timing advances. Therefore, the assist timing is set to advance as the ignition timing advances.
  • the maximum generateable energy calculator 44 a calculates the maximum generateable energy based on the power supply voltage of the ignition coil 16 .
  • the energy that can be stored in ignition coil 16 is proportional to the square of the voltage of the power supply connected to ignition coil 16 .
  • the stored energy will decrease by 27% at 12V and by 50% at 10V.
  • the coil power supply voltage may fluctuate. Since the relationship between the battery voltage (VB) and the maximum energy that can be generated depends on the specifications of the ignition coil 16, the relationship between the two should be investigated in advance and the maximum energy that can be generated should be stored as a voltage map. From the same relationship, the amount of energy that can be generated according to the power supply voltage is calculated.
  • the target dilution correction unit 44b performs control to correct the dilution (EGR rate and air-fuel ratio) based on the calculated amount of energy that can be generated.
  • G/F gas fuel ratio
  • EGR gas air, EGR gas, moisture (humidity)
  • G/F at which ignition becomes unstable differs depending on the gas composition.
  • the G/F at which ignition becomes unstable when the mixture is diluted with EGR gas is smaller than the G/F at which ignition becomes unstable when the mixture is diluted with air. This is thought to occur because air contains oxygen and is therefore more reactive than EGR gas.
  • ⁇ is a numerical value of about 3.
  • ⁇ is 1 in a normal G/F. This formula intends that the effect of 1 g of EGR gas on ignitability is equivalent to that of air ⁇ (g).
  • a realizable effective (G/F) is calculated based on the maximum possible energy calculated by the maximum possible energy calculation unit 44a.
  • the relationship between the coil generated energy and the achievable effective G/F is investigated in advance by tests and simulations, and then mapped. Calculate G/F.
  • the realizable effective G/F is the upper limit G/F.
  • Step S1302 It is determined whether the current effective G/F (actual effective G/F) calculated from the exhaust A/F, EGR rate, and equation (4) is smaller than the upper limit G/F calculated in step S1301. If the actual effective G/F is smaller than the upper limit G/F, the process proceeds to step S1307. If the actual effective G/F is larger than the upper limit G/F, the process proceeds to step S1303.
  • Step S1303 It is determined whether the exhaust A/F (current A/F) is greater than the lean A/F lower limit. If the current A/F is greater than the lean A/F lower limit, the process proceeds to step S1304. On the other hand, if the current A/F is smaller than the lean A/F lower limit, the process proceeds to step S1306. This determination is the same as determining whether lean combustion is currently being performed.
  • Step S1304 It is determined whether the upper limit G/F is greater than the minimum value of A/F (lean A/F lower limit) allowed for lean burn operation. If the upper limit G/F is greater than the lean A/F lower limit, that is, if an A/F exceeding the lean A/F lower limit can be set and lean combustion operation is possible, the process proceeds to step S1305.
  • the target EGR rate is set from the following relational expression (5), and the target A/F is set to the lean A/F lower limit.
  • Target EGR rate (upper limit G/F - lean A/F lower limit) ⁇ ⁇ (5)
  • Step S1306 The target air-fuel ratio is set to the stoichiometric air-fuel ratio, and the target EGR rate is set from the following relational expression (6).
  • Target EGR rate (upper limit G/F - stoichiometric A/F) ⁇ ⁇ (6)
  • A/Fst in S1306 of FIG. 13 represents the stoichiometric A/F (stoichiometric air-fuel ratio).
  • FIG. 14 shows the EGR rate and A/F movement when the processing shown in FIG. 13 is executed.
  • FIG. 14 shows, from the top, the power supply voltage of the ignition coil 16, maximum generateable energy, effective G/F, A/F, and EGR rate. As the power supply voltage of the ignition coil 16 decreases, the maximum generateable energy decreases.
  • the dashed lines in the effective G/F and A/F indicate changes in the upper limit G/F associated with changes in the maximum generateable energy.
  • the upper limit G/F begins to fall below the effective G/F.
  • the A/F target value is set to the lean A/F lower limit while maintaining the lean combustion setting. be.
  • the target EGR rate is set so as to satisfy the upper limit G/F.
  • Various actuators throttle valve, EGR valve) are operated to change the A/F and the EGR rate so as to satisfy such target setting.
  • the A/F becomes the lean A/F lower limit at time t1
  • the upper limit G/F changes at time t2.
  • the EGR rate reaches 0%
  • the situation is such that the reduction in the upper limit G/F cannot be dealt with by reducing the EGR rate.
  • the target value of A/F is set to stoichiometric A/F (A/Fst), and the target value of EGR rate is set so that the effective G/F becomes the upper limit G/F, and various actuators are operated. be done.
  • FIG. 15 is a control block showing an outline of the discharge energy control performed by the ignition control section 24 in the ECU 20, which is the control device for the internal combustion engine according to the second embodiment of the present invention.
  • the target ignition total energy calculator 151 is the same as in FIG.
  • the target ignition energy realization unit 152 determines the operation amount of the spark plug 17 based on the target ignition total energy amount, the required torque, the rotation speed, the operation amounts of the variable valve and the tumble control valve, and the ignition timing.
  • the energization period of the primary coil, which determines the basic current waveform, and the timing and period of the assist are set, calculated, and output.
  • FIG. 16 shows a control flow of arithmetic processing for ignition control in the first embodiment.
  • Step S1601 is a process executed by target ignition total energy calculation section 151 in FIG. 15, and step S1602 is a process executed by target ignition energy realization section 152.
  • FIG. 16 shows a control flow of arithmetic processing for ignition control in the first embodiment.
  • Step S1601 is a process executed by target ignition total energy calculation section 151 in FIG. 15, and step S1602 is a process executed by target ignition energy realization section 152.
  • Step S1601 The processing of step S1601 is the same as that of step S501 in FIG.
  • step S1602 it is determined whether assistance is required. For example, the necessity of assistance is determined from the target ignition total energy and the basic setting of the primary current supply period set for each operating condition. For this determination, as operating conditions, the engine torque, rotation speed, and primary coil energization period according to the dilution are mapped, and from the map, the current operating conditions and the primary coil according to the dilution determine the amount of current applied to the
  • the energy generated by the energization of the primary coil is calculated by mapping the energy that can be generated by the ignition coil 16 only by energizing the primary coil according to the same energization amount and the power supply voltage. Furthermore, it is determined whether the calculated energy satisfies the target ignition total energy. If it is determined that it is not satisfied, it is determined that assistance is required, and if it is determined that it is satisfied, it is determined that assistance is not required. Alternatively, the need for assistance may be mapped for each operating condition and degree of dilution, and the need for assistance may be determined based on the map, actual operating conditions, and degree of dilution.
  • step S1603 when it is determined in step S1602 that assistance is required, an assist timing is calculated from the operation amount of the actuator.
  • the assist timing must be set according to the flow velocity around the plug at the ignition timing.
  • the flow velocity is not estimated, and the assist timing is operated according to the correlation between the flow velocity and the actuator. For example, there is a method of finding the assist timing by multiplying the standard assist delay for each operating condition and the assist delay correction coefficient based on each of the variable valve operation amount, the tumble control valve opening, and the ignition timing.
  • 17A to 17D are used to determine the relationship between the operating conditions, the reference assist delay, the variable valve operation amount, the tumble control valve opening, and the ignition timing, and the correction coefficient when obtaining the assist delay by this method. to explain. 17A to 17D show a relationship 171 between the operating conditions and the reference assist delay, a relationship 172 between the variable valve operation amount and the correction coefficient, a relationship 173 between the tumble control valve opening and the correction coefficient, and a relation 174 between the ignition timing and the correction coefficient. show.
  • the operating conditions include the rotational speed of the engine and the torque generated by the engine (engine torque).
  • engine torque The angular velocity of the vortex formed inside the engine tends to change according to the rotational speed of the engine, and the higher the engine rotational speed, the greater the flow velocity at ignition timing.
  • the greater the engine torque the more air is introduced into the engine cylinder, which may increase the momentum in the engine cylinder and increase the flow velocity.
  • the reference assist delay has a characteristic that it becomes smaller (negative correlation) as the engine torque increases and becomes smaller (negative correlation) as the rotational speed increases (Fig. 17A).
  • the assist delay correction coefficient has a characteristic of having a minimum value in a given range of the operation amount of the variable valve. Become. The greater the difference between the actual operation amount and the operation amount (reference operation amount) of the variable valve mechanism that maximizes the flow velocity, the greater the assist delay. That is, there is a positive correlation between the difference between the reference operation amount and the actual operation and the assist delay.
  • the variable valve when the variable valve is operated to close the intake valve extremely early, the flow in the engine cylinder is damped, and the flow velocity at the ignition timing becomes smaller, so the assist delay becomes smaller. Also, if the closing timing of the intake valve is extremely late, part of the air introduced into the engine cylinder will blow back into the intake pipe, reducing the momentum in the engine cylinder and reducing the flow velocity at the ignition timing. Assist delay becomes small.
  • the change in the assist delay with respect to the operation amount of the variable valve has a characteristic that has a minimum value within a predetermined range (Fig. 17B).
  • the tumble control valve is a mechanism that increases the flow rate of gas flowing into the engine by closing part of the flow path by operating the control valve.
  • a large degree of opening of the tumble control valve indicates that the flow path is blocked by a relatively small amount.
  • the opening of the tumble control valve is large, the amount that blocks the flow path is relatively small, and the flow velocity at the ignition timing becomes small.
  • the assist delay becomes small because the flow velocity at the ignition timing becomes large.
  • the assist delay correction coefficient has a positive correlation with the opening of the tumble control valve (Fig. 17C). If the vortex formed in the cylinder is a tumble vortex, the vortex will attenuate as the piston rises, and the flow velocity around the plug will tend to decrease, so the assist delay will increase as the ignition timing is retarded. . Therefore, as the ignition timing advances, the assist delay correction coefficient decreases (FIG. 17D). The correction map based on the ignition timing is set so that the correction coefficient for the assist delay becomes smaller as the ignition timing is advanced.
  • the assist delay can be calculated in step S1603.
  • the relationship between the actuator and the assist when operated in the same steps is the same as that described with reference to FIGS.
  • the processor (CPU 23a, FIG. 3) of the control device (ECU 20, FIG. 3) of the internal combustion engine determines the operating conditions of the internal combustion engine (e.g., required torque, rotational speed) and the dilution state of the air-fuel mixture (e.g., EGR rate, air-fuel ratio). (target ignition total energy calculation unit 41, FIG. 4).
  • the processor (CPU 23a) calculates the parameters of the internal combustion engine (for example, the opening of the tumble control valve, the amount of operation of the variable valve mechanism, the opening of the throttle, the ignition Based on the timing), the ignition device is caused to assist the discharge current, and the ignition device is caused to generate ignition energy corresponding to the target ignition total energy (target ignition energy realization section 43, FIG. 4).
  • the discharge current is assisted according to the parameters of the internal combustion engine that are correlated with the flow velocity, and the reformation of the discharge path is suppressed.
  • ignition failure of the internal combustion engine can be suppressed.
  • the discharge current at the beginning of the discharge can be suppressed.
  • wear of the spark plug 17 can be suppressed.
  • the processor determines the operating conditions of the internal combustion engine (e.g., required torque, rotational speed), the operation amount of an actuator that controls the flow state of the air-fuel mixture in the cylinder of the internal combustion engine (e.g., the opening of the tumble control valve , operation amount of the variable valve mechanism) and the ignition timing, the flow velocity of the air-fuel mixture in the cylinder of the internal combustion engine at the ignition timing is estimated (ignition timing flow velocity calculator 42, FIG. 4).
  • the operating conditions of the internal combustion engine e.g., required torque, rotational speed
  • the operation amount of an actuator that controls the flow state of the air-fuel mixture in the cylinder of the internal combustion engine e.g., the opening of the tumble control valve , operation amount of the variable valve mechanism
  • the ignition timing e.g., the flow velocity of the air-fuel mixture in the cylinder of the internal combustion engine at the ignition timing is estimated (ignition timing flow velocity calculator 42, FIG. 4).
  • a parameter of the internal combustion engine that correlates with the flow velocity is, for example, a flow velocity estimated value that indicates the value of the flow velocity estimated by the processor (CPU 23a).
  • the processor (CPU 23a) reduces the assist delay, which indicates the time from the discharge start timing to the timing at which the discharge current assist is started, as the flow velocity estimated value increases (FIGS. 8A, 8B, etc.).
  • the discharge current is assisted at the timing according to the estimated flow velocity.
  • the flow velocity can be estimated without using an in-cylinder flow velocity sensor (flow rate sensor).
  • the processor increases the flow speed due to changes in parameters of the internal combustion engine (for example, the opening of the tumble control valve, the amount of operation of the variable valve mechanism, the opening of the throttle, and the ignition timing) that are correlated with the flow speed. Decrease the delay (FIGS. 17A-17D).
  • the discharge current is assisted at the timing according to the parameters of the internal combustion engine that are correlated with the flow velocity.
  • a parameter of the internal combustion engine that correlates with the flow velocity is, for example, the manipulated variable of the actuator (eg, tumble control valve, variable valve mechanism, throttle valve) that controls the flow state of the air-fuel mixture in the cylinder of the internal combustion engine.
  • the discharge current is assisted at the timing according to the operation amount of the actuator that correlates with the flow velocity (FIGS. 17A, 17B, 17C, etc.).
  • the actuator is, for example, a tumble control valve.
  • the processor CPU 23a
  • the discharge current is assisted at a timing corresponding to the degree of opening of the tumble control valve.
  • the actuator is, for example, a variable valve mechanism (variable valve 5, FIG. 1) that adjusts the timing of closing the intake valve.
  • the processor CPU 23a
  • the discharge current is assisted at the timing according to the difference between the operation amount of the variable valve mechanism and the reference operation amount.
  • the actuator is, for example, a throttle valve (electronic control throttle 2, Fig. 1).
  • the processor CPU 23a reduces the assist delay as the throttle opening (engine torque) increases (FIG. 17A, etc.). As a result, the discharge current is assisted at a timing corresponding to the opening of the throttle.
  • a parameter of the internal combustion engine that correlates with flow velocity is, for example, ignition timing.
  • the processor CPU 23a reduces the assist delay as the ignition timing advances (FIG. 17D, etc.). As a result, the discharge current is assisted at a timing corresponding to the ignition timing.
  • the parameter of the internal combustion engine that correlates with the flow velocity may be the expansion speed of the discharge plasma at the ignition timing.
  • the processor CPU 23a reduces the assist delay as the decompression speed increases.
  • the discharge current is assisted at a timing corresponding to the expansion speed of the discharge plasma.
  • the ignition device includes an ignition coil 16 (primary coil, secondary coil and tertiary coil) and a spark plug 17 (Fig. 2A).
  • an ignition coil 16 primary coil, secondary coil and tertiary coil
  • a spark plug 17 Fig. 2A.
  • the processor (CPU 23a), as shown in FIGS. 8A and 8B, when the target ignition total energy is larger than a predetermined range (the target total energy is medium) (that is, when the target total energy is large), and when the target ignition total energy is When the target total energy is within a predetermined range (medium target total energy) and the flow velocity is less than the threshold value, the primary coil and the tertiary coil generate energy corresponding to the target ignition total energy in the secondary coil.
  • the processor determines whether the target ignition total energy is within a predetermined range (target total energy is medium). If less (ie target total energy is small), the primary coil alone will cause the secondary coil to generate energy corresponding to the target ignition total energy (FIGS. 8A and 8B).
  • the timing of energizing the tertiary coil is advanced as the flow velocity increases (FIGS. 8A and 8B).
  • the processor increases the flow velocity when the target ignition total energy is within a predetermined range (target total energy is medium) and when the target ignition total energy is smaller than the predetermined range (target total energy is small).
  • the energization period to the primary coil is lengthened accordingly.
  • the processor (CPU 23a) calculates the maximum generateable energy of the ignition device based on the voltage (eg, battery voltage) of the charging power source of the ignition device (maximum generateable energy calculator 44a, FIG. 4).
  • the processor (CPU 23a) decreases the target value of the dilution of the air-fuel mixture as the maximum generateable energy decreases (target dilution correction unit 44b, FIG. 4). As a result, deterioration in efficiency of the internal combustion engine due to changes in the power supply voltage can be suppressed.
  • the present invention is not limited to the above-described embodiments, and includes various modifications.
  • the above-described embodiments have been described in detail in order to explain the present invention in an easy-to-understand manner, and are not necessarily limited to those having all the described configurations.
  • part of the configuration of one embodiment can be replaced with the configuration of another embodiment, and the configuration of another embodiment can be added to the configuration of one embodiment.
  • each of the above configurations, functions, etc. may be realized by hardware, for example, by designing a part or all of them with an integrated circuit.
  • each of the above configurations, functions, etc. may be realized by software by a processor interpreting and executing a program for realizing each function.
  • Information such as programs, tables, and files that implement each function can be stored in a recording device such as a memory, a hard disk, an SSD (Solid State Drive), or a recording medium such as an IC card, SD card, or DVD.
  • a control device for an internal combustion engine that controls an internal combustion engine having an ignition device, wherein the ignition device has a mechanism for assisting the discharge current during the discharge period, and the target ignition total energy is determined based on the operating conditions and the dilution state of the air-fuel mixture. and a target ignition energy realization part for realizing the target ignition total energy by assisting the current based on a parameter correlated with the flow velocity inside the internal combustion engine at the ignition timing.
  • a control device for an internal combustion engine that controls an internal combustion engine having an ignition device, wherein the ignition device has a mechanism for assisting the discharge current during the discharge period, and the target ignition total energy is determined based on the operating conditions and the dilution state of the air-fuel mixture. and a target ignition energy realization part for realizing the target ignition total energy by assisting the current based on a parameter correlated with the flow velocity inside the internal combustion engine at the ignition timing.
  • an ignition timing flow velocity estimator for estimating a flow velocity at the ignition timing based on an operating condition and an operation amount of an actuator for controlling a flow state inside the internal combustion engine and ignition timing, wherein a parameter correlated with the flow velocity is the ignition timing flow velocity
  • the control device characterized in that the flow velocity estimated value estimated by the estimation unit.
  • control device flow velocity generalization of correlation parameters and manipulated variables.
  • the actuator for controlling the flow state of the internal engine is an engine tumble control valve provided in the intake pipe of the internal combustion engine, and the degree of opening of the tumble control valve and the period until the assist are positively correlated.
  • (5) (small opening of tumble control valve ( large flow velocity) ⁇ short period until assist).
  • the actuator for controlling the flow state of the internal combustion engine is a variable valve mechanism of the internal combustion engine.
  • control device (10) The control device according to (1) or (4), characterized in that the parameter correlated with the flow velocity is the elongation velocity of the discharge plasma at the ignition timing.
  • control device characterized in that the expansion speed of the discharge plasma and the time from the start of discharge to the start of current assist have a negative correlation.
  • the target ignition total energy is calculated based on an engine operating condition parameter and a parameter indicating the dilution state of the air-fuel mixture, at least one of the operating condition parameters is an index correlated with engine torque, and the air-fuel mixture At least one of the parameters indicating the dilution state of is an index that correlates with the dilution rate of the air-fuel mixture, the greater the engine torque, the greater the total energy is set, and the greater the dilution rate, the greater the total energy is set.
  • the control device according to (1) to (11) characterized by:
  • a maximum possible energy calculation unit that calculates the maximum possible energy of the ignition device based on the charging power source of the ignition device; and a target dilution correction unit that corrects the target value of the mixture dilution based on the maximum possible energy.
  • the current can be added to the basic current waveform at an appropriate timing after considering the flow velocity around the spark plug at the ignition timing.
  • the discharge energy can be reduced from the required discharge energy of the system, which is determined by the ignition retard conditions, so that the heat generation of the ignition coil and the wear of the spark plug can be suppressed, and the durability of the system can be improved. can be done.

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  • Chemical & Material Sciences (AREA)
  • Combustion & Propulsion (AREA)
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  • General Engineering & Computer Science (AREA)
  • Electrical Control Of Ignition Timing (AREA)
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Abstract

A processor of an internal combustion engine control device according to the present invention calculates a target ignition total energy representing a target value of the energy required for ignition of an air-fuel mixture in a cylinder of the internal combustion engine, on the basis of an operating condition of the internal combustion engine and a dilution state of the air-fuel mixture (target ignition total energy calculating unit 41). On the basis of a parameter of the internal combustion engine correlated to the flow rate of the air-fuel mixture in the cylinder of the internal combustion engine at the ignition timing, the processor causes an ignition device to assist a discharge current, and causes the ignition device to generate ignition energy corresponding to the target ignition total energy (target ignition energy realizing unit 43).

Description

内燃機関の制御装置Control device for internal combustion engine
　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.
　自動車の燃費性能を向上するためには種々の方法があるが、内燃機関の燃料消費量を低減することが重要である。燃料消費量の低減には、内燃機関の運転中に発生するポンプ損失、冷却損失、排気損失、といった各種損失の低減が有効であり、ポンプ損失、冷却損失の低減手段として、燃料と空気の比率を量論混合比（理論混合比）に比べて希薄にして燃焼させる希薄燃焼や、燃焼ガスの一部を吸気側に戻して燃料と空気の混合気を希釈するＥＧＲ（Ｅｘｈａｕｓｔ　Ｇａｓ　Ｒｅｃｉｒｃｕｌａｔｉｏｎ）ガスを活用した燃焼方式がある。以下では、希薄燃焼やＥＧＲガスを活用した燃焼方式をまとめて「希釈燃焼」と記載する。 There are various ways to improve the fuel efficiency of automobiles, but it is important to reduce the fuel consumption of internal combustion engines. In order to reduce fuel consumption, it is effective to reduce various losses such as pump loss, cooling loss, and exhaust loss that occur during operation of the internal combustion engine. lean combustion compared to the stoichiometric mixture ratio (stoichiometric mixture ratio), and EGR (Exhaust Gas Recirculation) gas that dilutes the mixture of fuel and air by returning part of the combustion gas to the intake side. There is a combustion method that is utilized. Hereinafter, the lean combustion and the combustion method utilizing EGR gas are collectively referred to as "dilution combustion".
　この希釈燃焼を用いると、希釈燃焼を用いない場合に比べて吸気管圧力を上げることができるので、内燃機関の負荷の低い条件でのポンプ損失の低減ができる。また、希釈燃焼を用いない場合に比べて、同一燃料量を燃焼させる際の熱容量を増加させることができるため、混合気の燃焼温度を低下して冷却損失の低減を図ることができる。また、内燃機関の負荷の高い条件では、ＥＧＲガスを導入することによる自着火反応に至る反応進行が抑制されることで、異常燃焼の発生が抑制できる。これによって点火時期を最適時期に近づけるように進角することができるため、排気損失の低減ができるようになる。 By using this dilution combustion, the intake pipe pressure can be increased compared to when dilution combustion is not used, so it is possible to reduce the pump loss under low load conditions of the internal combustion engine. In addition, compared to the case where dilution combustion is not used, the heat capacity when burning the same amount of fuel can be increased, so the combustion temperature of the air-fuel mixture can be lowered and the cooling loss can be reduced. In addition, under conditions where the load of the internal combustion engine is high, the occurrence of abnormal combustion can be suppressed by suppressing the reaction progress leading to the self-ignition reaction due to the introduction of the EGR gas. As a result, the ignition timing can be advanced so as to approach the optimum timing, so that the exhaust loss can be reduced.
　さて、燃料消費量を低減するためには、運転条件に応じて適切な混合気の希釈度（以下に示すガス燃料比）を設定する必要が有る。混合気の希釈度は、空気やＥＧＲガスからなる混合ガスの質量和と燃料の質量の比（ガス燃料比Ｇ／Ｆ）、空気と燃料の質量比（空燃比Ａ／Ｆ）、吸気ガス中のＥＧＲの割合（ＥＧＲ率）で評価することが多い。 Now, in order to reduce fuel consumption, it is necessary to set an appropriate mixture dilution (gas fuel ratio shown below) according to the operating conditions. The degree of dilution of the air-fuel mixture is the ratio of the mass sum of the mixed gas consisting of air and EGR gas to the fuel mass (gas-fuel ratio G/F), the air-to-fuel mass ratio (air-fuel ratio A/F), the intake gas EGR ratio (EGR rate) is often evaluated.
　希釈度の大きな条件（希薄な混合気の状態）で失火を避けて燃焼を実現するためには、燃料の相対的な濃度が小さくなっているので、火花点火時に点火プラグから気筒内の混合気に供給する放電エネルギ量を増加させる必要が有る。また、供給する放電エネルギ量に対して影響を与える因子として、点火時期におけるプラグ周囲の混合気の流速がある。例えば、点火時期におけるプラグ周囲の混合気の流速が大きいと、放電の吹き消えが発生し、失火につながることが良く知られている。 In order to achieve combustion while avoiding misfiring under conditions of high dilution (state of lean air-fuel mixture), the relative concentration of the fuel is low, so the air-fuel mixture in the cylinder is released from the spark plug during spark ignition. It is necessary to increase the amount of discharge energy supplied to the Further, the flow velocity of the air-fuel mixture around the plug at the ignition timing is a factor that affects the amount of discharge energy to be supplied. For example, it is well known that if the flow velocity of the air-fuel mixture around the plug at the ignition timing is high, the discharge will blow out, leading to misfiring.
　このため、筒内の流れの状態に応じて、点火プラグから気筒内の混合気に供給する放電エネルギ量を増加することが有効であることが知られており、例えば、特開２０１９－１６３７４５号公報（特許文献１）に記載されている内燃機関制御装置がある。この特許文献１は、放電電流波形の与え方を筒内の流速に応じて変更することを提案している。具体的には、放電電流波形において、電流値を所定値に維持する期間を設ける場合に、初期値から当該所定値までの変化率を流速に応じて設定する点火装置を提案している。 Therefore, it is known that it is effective to increase the amount of discharge energy supplied to the air-fuel mixture in the cylinder from the spark plug according to the state of the flow in the cylinder. There is an internal combustion engine control device described in a publication (Patent Document 1). This patent document 1 proposes changing how to give the discharge current waveform according to the flow velocity in the cylinder. Specifically, in the discharge current waveform, when providing a period during which the current value is maintained at a predetermined value, an ignition device is proposed in which the rate of change from the initial value to the predetermined value is set according to the flow velocity.
特開２０１９－１６３７４５号公報JP 2019-163745 A
　特許文献１においては、初期電流に対して、維持する所定値が大きい場合に、流速に応じて初期値から当該所定値までの変化率を設定することで、火花放電の吹き消えの防止と、確実な点火を実現しつつ、無駄なエネルギ供給を抑制することができる。しかしながら、特許文献１では、点火プラグの摩耗について考慮されていない。 In Patent Document 1, when the predetermined value to be maintained is large with respect to the initial current, by setting the rate of change from the initial value to the predetermined value according to the flow velocity, the spark discharge is prevented from blowing out, Wasteful energy supply can be suppressed while achieving reliable ignition. However, Patent Document 1 does not consider wear of the spark plug.
　本発明の目的は、内燃機関の着火不良を抑制しつつ、点火プラグの摩耗を抑制することができる内燃機関の制御装置を提供することにある。 An object of the present invention is to provide a control device for an internal combustion engine that can suppress wear of spark plugs while suppressing ignition failure of the internal combustion engine.
　上記目的を達成するために、本発明の内燃機関の制御装置は、内燃機関の運転条件及び混合気の希釈状態に基づいて、前記内燃機関の筒内の混合気の点火に必要なエネルギの目標値を示す目標点火トータルエネルギを算出し、点火時期における前記内燃機関の筒内の混合気の流速に相関を持つ前記内燃機関のパラメータに基づいて、点火装置に放電電流をアシストさせるとともに、前記点火装置に前記目標点火トータルエネルギに応じた点火エネルギを発生させるプロセッサを備える。 In order to achieve the above object, the control apparatus for an internal combustion engine of the present invention provides a target energy required for ignition of an air-fuel mixture in a cylinder of the internal combustion engine based on the operating conditions of the internal combustion engine and the dilution state of the air-fuel mixture. A target ignition total energy indicating a value is calculated, and based on the parameter of the internal combustion engine that has a correlation with the flow velocity of the air-fuel mixture in the cylinder of the internal combustion engine at the ignition timing, the ignition device is caused to assist the discharge current, and the ignition The device includes a processor for generating ignition energy corresponding to the target ignition total energy.
　本発明によれば、内燃機関の着火不良を抑制しつつ、点火プラグの摩耗を抑制することができる。上記した以外の課題、構成及び効果は、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 suppress wear of the spark plug while suppressing ignition failure of the internal combustion engine. Problems, configurations, and effects other than those described above will be clarified by the following description of the embodiments.
内燃機関のシステム構成を示す構成図である。1 is a configuration diagram showing a system configuration of an internal combustion engine; FIG. 点火コイルの構成図である。It is a block diagram of an ignition coil. 点火コイルに発生する電流を説明する図である。It is a figure explaining the electric current which generate|occur|produces in an ignition coil. 本発明が適用される内燃機関の制御装置の構成図である。1 is a configuration diagram of a control device for an internal combustion engine to which the present invention is applied; FIG. 本発明の実施形態の制御ブロック図である。It is a control block diagram of an embodiment of the present invention. 本発明の実施形態の制御ブロックで実行する制御ステップを説明するための制御フローチャートである。4 is a control flow chart for explaining control steps executed by a control block according to an embodiment of the present invention; 当量比と基準エネルギの関係を示す特性図である。FIG. 4 is a characteristic diagram showing the relationship between equivalence ratio and reference energy; ＥＧＲ率と補正係数の関係を示す特性図である。FIG. 4 is a characteristic diagram showing the relationship between an EGR rate and a correction coefficient; 点火時期圧力と補正係数の関係を示す特性図である。FIG. 5 is a characteristic diagram showing the relationship between ignition timing pressure and correction coefficient; 点火時期温度と補正係数の関係を示す特性図である。FIG. 5 is a characteristic diagram showing the relationship between ignition timing temperature and correction coefficient; 運転条件と基準流速の関係を示す特性図である。FIG. 4 is a characteristic diagram showing the relationship between operating conditions and reference flow velocity; 可変バルブと補正係数の関係を示す特性図である。FIG. 4 is a characteristic diagram showing the relationship between a variable valve and a correction coefficient; タンブル制御弁と補正係数の関係を示す特性図である。FIG. 4 is a characteristic diagram showing the relationship between a tumble control valve and a correction coefficient; 点火時期と補正係数の関係を示す特性図である。FIG. 4 is a characteristic diagram showing the relationship between ignition timing and correction coefficient; 目標点火トータルエネルギごとの流速に応じた１次通電期間と放電開始後の電流アシストタイミングの関係を示す特性図である。FIG. 5 is a characteristic diagram showing the relationship between the primary energization period and the current assist timing after the start of discharge according to the flow velocity for each target ignition total energy. 実現される電流波形を示す特性図である。FIG. 4 is a characteristic diagram showing a current waveform that is realized; 回転数が変わった場合の各種アクチュエータの状態を示すタイミングチャートである。4 is a timing chart showing states of various actuators when the number of revolutions changes. 可変バルブ操作量が変わった場合の各種アクチュエータの状態を示すタイミングチャートである。4 is a timing chart showing states of various actuators when a variable valve operation amount changes; タンブル制御弁とスロットルバルブ開度が変わった場合の各種アクチュエータの状態を示すタイミングチャートである。4 is a timing chart showing the states of various actuators when the tumble control valve and throttle valve opening are changed. 点火時期が変わった場合の各種アクチュエータの状態を示すタイミングチャートである。4 is a timing chart showing states of various actuators when ignition timing is changed; 本発明の実施形態の制御ブロックで実行する制御ステップを説明するための制御フローチャートである。4 is a control flow chart for explaining control steps executed by a control block according to an embodiment of the present invention; バッテリ電圧が変わった場合の希釈度の目標値、実値の状態を示すタイミングチャートである。4 is a timing chart showing target values and actual values of dilution when the battery voltage changes. 本発明の第２の実施形態の制御ブロック図である。It is a control block diagram of the 2nd Embodiment of this invention. 本発明の実施形態の制御ブロックで実行する制御ステップを説明するための制御フローチャートである。4 is a control flow chart for explaining control steps executed by a control block according to an embodiment of the present invention; 運転条件と基準アシストまでの期間（アシスト遅れ）の関係を示す特性図である。FIG. 10 is a characteristic diagram showing the relationship between operating conditions and a period (assist delay) until reference assist. 可変バルブと補正係数の関係を示す特性図である。FIG. 4 is a characteristic diagram showing the relationship between a variable valve and a correction coefficient; タンブル制御弁の開度と補正係数の関係を示す特性図である。FIG. 4 is a characteristic diagram showing the relationship between the degree of opening of a tumble control valve and a correction coefficient; 点火時期と補正係数の関係を示す特性図である。FIG. 4 is a characteristic diagram showing the relationship between ignition timing and correction coefficient;
　以下、本発明の実施形態について図面を用いて詳細に説明するが、本発明は以下の実施形態に限定されることなく、本発明の技術的な概念の中で種々の変形例や応用例をもその範囲に含むものである。 Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. However, the present invention is not limited to the following embodiments, and various modifications and applications can be made within the technical concept of the present invention. is also included in the scope.
　本発明の実施形態は内燃機関の制御装置に係り、特に点火コイルを利用して点火プラグに火花放電を発生して混合気に着火する火花点火式の内燃機関に使用される内燃機関の制御装置に関するものである。本発明の実施形態の目的は、放電電流が、基本電流波形に対して、任意のタイミングで電流を加算できるような仕組みを対象に、点火時期におけるプラグ周囲の流速を考慮して、放電エネルギ波形を設定することができる内燃機関の制御装置を提供することにある。 Embodiments of the present invention relate to a control device for an internal combustion engine, and particularly to a control device for an internal combustion engine that is used in a spark ignition type internal combustion engine that uses an ignition coil to generate spark discharge in a spark plug to ignite an air-fuel mixture. It is about. The purpose of the embodiments of the present invention is to provide a mechanism in which the discharge current can be added to the basic current waveform at arbitrary timing. To provide a control device for an internal combustion engine that can set
　［第１の実施形態］
　以下、図面を参照しながら、本発明の実施形態について説明するが、以下に示す実施形態に共通の構成を図１乃至図３を用いて説明する。 [First embodiment]
Hereinafter, embodiments of the present invention will be described with reference to the drawings, and a configuration common to the embodiments shown below will be described with reference to FIGS. 1 to 3. FIG.
　図１は、自動車に使用される火花点火式内燃機関のシステム構成を示しており、ガソリン燃料を気筒内に直接噴射する筒内燃料噴射装置１３を備えている。 FIG. 1 shows the system configuration of a spark ignition type internal combustion engine used in automobiles, and includes an in-cylinder fuel injection device 13 that directly injects gasoline fuel into the cylinder.
　内燃機関ＥＮＧは、火花点火燃焼を実施する自動車用の筒内噴射式内燃機関である。吸入空気量及び吸気温度を計測するエアフローセンサ１と、吸気を過給するための過給機のコンプレッサ４ａと、吸気を冷却するためのインタークーラ７と、吸気管圧力を調整する電子制御スロットル２、不図示の湿度センサとタンブル制御弁が吸気管の各々の適宜位置に備えられている。 The internal combustion engine ENG is an in-cylinder injection internal combustion engine for automobiles that performs spark ignition combustion. An air flow sensor 1 for measuring the intake air amount and intake air temperature, a supercharger compressor 4a for supercharging the intake air, an intercooler 7 for cooling the intake air, and an electronically controlled throttle 2 for adjusting the intake pipe pressure. , a humidity sensor (not shown) and a tumble control valve are provided at appropriate positions in each of the intake pipes.
　ここで、湿度センサは相対湿度及び絶対湿度が検出可能なセンサである。また、内燃機関ＥＮＧには、各気筒のシリンダ１４の中に燃料を噴射する燃料噴射装置１３（インジェクタ）と、点火エネルギを供給する点火装置（以下、点火コイル１６、点火プラグ１７）が気筒ごとに備えられている。 Here, the humidity sensor is a sensor that can detect relative humidity and absolute humidity. In the internal combustion engine ENG, a fuel injection device 13 (injector) for injecting fuel into the cylinder 14 of each cylinder and an ignition device (hereinafter referred to as ignition coil 16 and spark plug 17) for supplying ignition energy are provided for each cylinder. provided for.
　また、気筒内に流入する混合気、又は気筒内から排出する排気ガスを調整する可変バルブ５が、シリンダヘッドに備えられている。可変バルブ５を調整することにより、全気筒の吸気量及び内部ＥＧＲ量を調整する。 Also, the cylinder head is provided with a variable valve 5 that adjusts the air-fuel mixture flowing into the cylinder or the exhaust gas discharged from the cylinder. By adjusting the variable valve 5, the intake air amount and the internal EGR amount of all cylinders are adjusted.
　また、図示していないが燃料噴射装置１３に高圧燃料を供給するための高圧燃料ポンプが燃料配管によって燃料噴射装置１３と接続されており、燃料配管中には、燃料噴射圧力を計測するための燃料圧力センサが備えられている。また、内燃機関のピストン位置を検知するためのクランク角度センサ１９が取り付けられている。クランク角度センサ１９の出力情報はＥＣＵ２０（Ｅｎｇｉｎｅ　Ｃｏｎｔｒｏｌ　Ｕｎｉｔ）に送られる。 A high-pressure fuel pump (not shown) for supplying high-pressure fuel to the fuel injection device 13 is connected to the fuel injection device 13 through a fuel pipe. A fuel pressure sensor is provided. Also, a crank angle sensor 19 is attached to detect the position of the piston of the internal combustion engine. Output information from the crank angle sensor 19 is sent to an ECU 20 (Engine Control Unit).
　更に、排気エネルギによって過給機のコンプレッサ４ａに回転力を与えるためのタービン４ｂと、タービン４ｂに流れる排気流量を調整するための電子制御ウェイストゲート弁１１と、排気を浄化する三元触媒１０と、空燃比検出器の一態様であって、三元触媒１０の上流側にて排気ガスの空燃比を検出する空燃比センサ９とが排気管１５の各々の適宜位置に備えられる。 Furthermore, a turbine 4b for applying rotational force to the compressor 4a of the supercharger by exhaust energy, an electronically controlled wastegate valve 11 for adjusting the flow rate of exhaust gas flowing to the turbine 4b, and a three-way catalyst 10 for purifying the exhaust gas. An air-fuel ratio sensor 9 for detecting the air-fuel ratio of the exhaust gas on the upstream side of the three-way catalyst 10 is provided at an appropriate position in each of the exhaust pipes 15 .
　また、図示していないが内燃機関を巡る冷却水の温度を計測する水温センサ１８が備えられている。さらに、図示していないが、排気管１５の三元触媒１０の下流から、吸気管のコンプレッサ４ａの上流に排気を還流させるためのＥＧＲ管を備えている。また、ＥＧＲ管には、ＥＧＲ流量を制御するためのＥＧＲバルブ（ＥＧＲ機構）が、ＥＧＲ管の各々の適宜位置に、取りつけられている。 Also, although not shown, a water temperature sensor 18 is provided to measure the temperature of cooling water that flows around the internal combustion engine. Further, although not shown, an EGR pipe is provided for recirculating exhaust gas from the exhaust pipe 15 downstream of the three-way catalyst 10 to the intake pipe upstream of the compressor 4a. EGR valves (EGR mechanism) for controlling the EGR flow rate are attached to the EGR pipes at appropriate positions.
　エアフローセンサ１、水温センサ１８と空燃比センサ９から得られる出力情報は、内燃機関を制御するコントロールユニット（ＥＣＵ２０）に送られる。また、アクセル開度センサ１２から得られる出力情報がＥＣＵ２０に送られている。アクセル開度センサ１２は、アクセルペダルの踏み込み量、すなわち、アクセル開度を検出する。 The output information obtained from the airflow sensor 1, the water temperature sensor 18 and the air-fuel ratio sensor 9 is sent to the control unit (ECU 20) that controls the internal combustion engine. Further, output information obtained from the accelerator opening sensor 12 is sent to the ECU 20 . The accelerator opening sensor 12 detects the depression amount of the accelerator pedal, that is, the accelerator opening.
　ＥＣＵ２０は、アクセル開度センサ１２の出力情報に基づいて、要求トルクを演算する。すなわち、アクセル開度センサ１２は、内燃機関への要求トルクを検出する要求トルク検出センサとして用いられる。また、ＥＣＵ２０は、クランク角度センサ１９の出力情報に基づいて、内燃機関の回転速度を演算する。ＥＣＵ２０は、上記各種センサの出力情報から得られる内燃機関の運転状態に基づき、空気流量、燃料噴射量、点火時期、燃料圧力等の内燃機関の主要な作動量を最適に演算する。 The ECU 20 calculates the required torque based on the output information from the accelerator opening sensor 12 . That is, the accelerator opening sensor 12 is used as a required torque detection sensor that detects the required torque to the internal combustion engine. The ECU 20 also calculates the rotation speed of the internal combustion engine based on output information from the crank angle sensor 19 . The ECU 20 optimally calculates main operating variables of the internal combustion engine, such as air flow rate, fuel injection amount, ignition timing, and fuel pressure, based on the operating conditions of the internal combustion engine obtained from the output information of the various sensors.
　ＥＣＵ２０で演算された燃料噴射量は開弁パルス信号に変換され、燃料噴射装置１３に送られる。また、ＥＣＵ２０で演算された点火時期で点火されるように、点火信号が点火コイル１６に送られる。また、ＥＣＵ２０で演算されたスロットル開度（スロットルバルブ開度ともいう）は、スロットル駆動信号として電子制御スロットル２に送られる。 The fuel injection amount calculated by the ECU 20 is converted into a valve opening pulse signal and sent to the fuel injection device 13 . Also, an ignition signal is sent to the ignition coil 16 so that the engine is ignited at the ignition timing calculated by the ECU 20 . Further, the throttle opening (also referred to as throttle valve opening) calculated by the ECU 20 is sent to the electronically controlled throttle 2 as a throttle drive signal.
　吸気管から吸気バルブを経てシリンダ１４内に流入した空気に対し、燃料が噴射され、混合気を形成する。混合気は所定の点火時期で点火プラグ１７から発生される火花により爆発し、その燃焼圧によりピストンを押し下げて内燃機関の駆動力となる。更に、爆発後の排気ガスは排気管１５を経て、三元触媒１０に送りこまれ、排気成分は三元触媒１０内で浄化され、外部へと排出される。 Fuel is injected into the air that has flowed into the cylinder 14 from the intake pipe through the intake valve to form an air-fuel mixture. The air-fuel mixture is exploded by a spark generated from the ignition plug 17 at a predetermined ignition timing, and the combustion pressure pushes down the piston to provide driving force for the internal combustion engine. Further, the exhaust gas after the explosion passes through the exhaust pipe 15 and is sent to the three-way catalyst 10, and the exhaust components are purified in the three-way catalyst 10 and discharged to the outside.
　点火コイル１６は、低電圧側（バッテリ側）の１次コイルと高電圧側の２次コイルで構成され、高電圧を生成する仕組みとなっている。これらの２つのコイルに加えて、低電圧側に電流アシストを可能とする３次コイルを備える点火コイル１６を適用した構成とする。図２Ａ、２Ｂに本実施形態で適用するコイルの構成例と同コイルを用いた際に発生する放電電流を示す。なお、図２Ａ、２Ｂでは、点火コイル１６に通電するための具体的な回路は図示しない。 The ignition coil 16 is composed of a primary coil on the low voltage side (battery side) and a secondary coil on the high voltage side, and is designed to generate high voltage. In addition to these two coils, an ignition coil 16 having a tertiary coil that enables current assist on the low voltage side is applied. 2A and 2B show a configuration example of the coil applied in this embodiment and the discharge current generated when the same coil is used. 2A and 2B, a specific circuit for energizing the ignition coil 16 is not shown.
　図２Ａは点火コイル１６の構成、図２Ｂには放電電流、操作量である１次コイル通電状態、３次コイル通電状態の時間履歴を示す。通電状態は、通電が行われている状態をＯＮ、通電が行われていない状態をＯＦＦで表す指標である。１次コイル通電ＯＮからＯＦＦに切り替えた際に高電圧側で放電電流が流れ始める。３次コイルへの通電が行われない場合、２次コイルに蓄積された磁気エネルギが放出され、徐々に放電電流が小さくなるように変化する。途中、３次コイルへ通電することで、２次コイルへのエネルギ供給をアシストすると、単調減少ではなく、放電電流の維持、増加などが可能になる。以下では、３次電流を通電することを電流アシスト、放電開始から電流アシスト開始までの時間をアシスト遅れ、と呼ぶ。 FIG. 2A shows the configuration of the ignition coil 16, and FIG. 2B shows the time history of the discharge current, the energized state of the primary coil, which is the manipulated variable, and the energized state of the tertiary coil. The energized state is an index that indicates a state in which energization is being performed by ON, and a state in which energization is not being performed by OFF. When the primary coil energization is switched from ON to OFF, a discharge current begins to flow on the high voltage side. When the tertiary coil is not energized, the magnetic energy accumulated in the secondary coil is released, and the discharge current gradually decreases. If the supply of energy to the secondary coil is assisted by energizing the tertiary coil on the way, it becomes possible to maintain or increase the discharge current instead of monotonically decreasing it. Hereinafter, energization of the tertiary current will be referred to as current assist, and the time from the start of discharge to the start of current assist will be referred to as assist delay.
　このような内燃機関システムにおいて、次に本実施形態の詳細について説明する。図３は、本発明が適用される内燃機関の制御装置の構成を示す構成図である。エアフローセンサ１からの空気量情報、アクセル開度センサ１２からのアクセル踏込情報、クランク角度センサ１９からの角度情報等の入力信号は、制御部であるＥＣＵ２０の入力回路２１に入力される。但し、入力信号はこれらだけに限られるものではないので、適宜に追加して説明する。 In such an internal combustion engine system, the details of the present embodiment will be described next. FIG. 3 is a configuration diagram showing the configuration of an internal combustion engine control device to which the present invention is applied. Input signals such as air amount information from the air flow sensor 1, accelerator depression information from the accelerator opening sensor 12, and angle information from the crank angle sensor 19 are input to an input circuit 21 of the ECU 20, which is a control unit. However, since the input signals are not limited to these, additional description will be given as appropriate.
　入力された各センサの入力信号は、入出力ポート２２内の入力ポートに送られる。入力ポートに送られた入力情報は、ＲＡＭ２３ｃに一時保管され、ＣＰＵ２３ａで、所定の制御プログラムにしたがって演算処理される。演算処理の内容を記述した制御プログラムは、ＲＯＭ２３ｂに予め書き込まれている。 The input signal of each sensor is sent to the input port within the input/output port 22 . The input information sent to the input port is temporarily stored in the RAM 23c and processed by the CPU 23a according to a predetermined control program. A control program describing the contents of arithmetic processing is written in the ROM 23b in advance.
　制御プログラムにしたがって演算された内燃機関を制御する燃料噴射装置１３や点火コイル１６への作動量を示す出力情報は、ＲＡＭ２３ｃに一時保管された後、入出力ポート２２内の出力ポートに送られ、夫々の駆動回路を経て燃料噴射装置１３や点火コイル１６へ送られる。尚、内燃機関にはこれら以外のアクチュエータも使用されているが、ここでは説明を省略する。 Output information indicating the amount of operation of the fuel injection device 13 and the ignition coil 16 for controlling the internal combustion engine calculated according to the control program is temporarily stored in the RAM 23c and then sent to the output port in the input/output port 22. It is sent to the fuel injection device 13 and the ignition coil 16 through the respective drive circuits. Although other actuators are also used in internal combustion engines, their description is omitted here.
　本実施形態の場合は、駆動回路として点火制御部２４を示しており、点火制御部２４は、点火コイル１６への通電時期や放電エネルギ量等を制御する。本実施形態においては、ＥＣＵ２０内に点火コイル１６への通電時間や放電エネルギ量を制御するための点火制御部２４を備えているが、これに限るものではなく、点火制御部２４の一部、又は、点火制御部２４の全てがＥＣＵ２０とは別の装置に実装されていても差し支えないものである。 In the case of this embodiment, the ignition control section 24 is shown as the drive circuit, and the ignition control section 24 controls the timing of energizing the ignition coil 16, the amount of discharge energy, and the like. In this embodiment, the ECU 20 is provided with an ignition control section 24 for controlling the energization time of the ignition coil 16 and the amount of discharge energy. Alternatively, the entire ignition control unit 24 may be mounted in a device separate from the ECU 20.
　そして、ＥＣＵ２０は検出した空気量、クランク角、冷却水温、吸気温度、湿度等に応じて、点火プラグ１７の放電エネルギを演算して適切なタイミング（通流時間や点火時期）に点火コイル１６へ通電して、気筒内の混合気に着火するものである。 Then, the ECU 20 calculates the discharge energy of the spark plug 17 according to the detected air amount, crank angle, cooling water temperature, intake air temperature, humidity, etc., and discharges the energy to the ignition coil 16 at an appropriate timing (conduction time or ignition timing). When energized, the air-fuel mixture in the cylinder is ignited.
　図４は、本発明の実施形態の内燃機関の制御装置であるＥＣＵ２０内の点火制御部２４で実施される放電エネルギ制御の概要を示す制御ブロックである。 FIG. 4 is a control block showing an outline of the discharge energy control performed by the ignition control section 24 in the ECU 20, which is the control device for the internal combustion engine of the embodiment of the present invention.
　目標点火トータルエネルギ算出部４１は、アクセル開度センサ１２の出力情報から算出された要求トルクと、クランク角度センサ１９の出力情報から算出された内燃機関の回転速度に基づいて、目標点火トータルエネルギ量を算出する機能を備えている。目標点火トータルエネルギ算出部４１で算出された目標点火トータルエネルギ量は、次段の目標点火エネルギ実現部４３に入力される。 A target ignition total energy calculation unit 41 calculates a target ignition total energy amount based on the required torque calculated from the output information of the accelerator opening sensor 12 and the rotational speed of the internal combustion engine calculated from the output information of the crank angle sensor 19. It has a function to calculate The target ignition total energy amount calculated by the target ignition total energy calculation section 41 is input to the next-stage target ignition energy realization section 43 .
　点火時期流速算出部４２は、要求トルクと、回転速度及び可変バルブ、タンブル制御弁の操作量及び点火時期に基づいて、点火時期のプラグ周囲流速を算出する機能を備えている。点火時期流速算出部４２で算出された点火時期のプラグ周囲流速も、次段の目標点火エネルギ実現部４３に入力される。 The ignition timing flow velocity calculation unit 42 has a function of calculating the plug peripheral flow velocity at the ignition timing based on the required torque, the rotational speed, the operation amount of the variable valve, the tumble control valve, and the ignition timing. The plug-periphery flow velocity at the ignition timing calculated by the ignition timing flow velocity calculator 42 is also input to the next-stage target ignition energy realization section 43 .
　目標点火エネルギ実現部４３は、目標点火トータルエネルギ量と点火時期のプラグ周囲流速に基づき、点火装置の操作量を決める。目標点火エネルギ実現部４３は、基本電流波形を決める１次コイルの通電期間と、アシストのタイミング、期間を設定算出し、出力する。 The target ignition energy realization unit 43 determines the operation amount of the ignition device based on the target ignition total energy amount and the flow velocity around the plug at the ignition timing. The target ignition energy realization unit 43 sets, calculates, and outputs the energization period of the primary coil that determines the basic current waveform, the timing of the assist, and the period.
　操作量補正部４４は、点火装置が発生できるエネルギ量の実現可否を判断し、目標エネルギに影響する混合気の希釈度や、流速に影響するアクチュエータの操作量を補正するブロックである。最大発生可能エネルギ算出部４４ａでは、点火コイル１６の電源電圧に基づき発生することができる最大エネルギを算出する。算出した最大エネルギは目標希釈度補正部４４ｂに入力する。目標希釈度補正部４４ｂは、同最大発生可能エネルギで実現可能な希釈度を算出し、算出した実現可能な希釈度に基づき、新たな空燃比の目標値（目標空燃比）とＥＧＲ率の目標（目標ＥＧＲ率）を算出する。 The manipulated variable correction unit 44 is a block that determines whether or not the amount of energy that can be generated by the ignition device can be realized, and corrects the degree of dilution of the air-fuel mixture that affects the target energy and the manipulated variable of the actuator that affects the flow velocity. The maximum generateable energy calculator 44 a calculates the maximum energy that can be generated based on the power supply voltage of the ignition coil 16 . The calculated maximum energy is input to the target dilution correction section 44b. The target dilution correction unit 44b calculates a dilution that can be achieved with the same maximum generateable energy, and based on the calculated dilution that can be achieved, sets a new air-fuel ratio target value (target air-fuel ratio) and an EGR rate target. (Target EGR rate) is calculated.
　図５は、第１の実施形態における点火制御のための演算処理の制御フローを示す。ステップＳ５０１は、図４の目標点火トータルエネルギ算出部４１で実行される処理であり、ステップＳ５０２は点火時期流速算出部４２で実行される処理である。さらに、ステップＳ５０３は目標点火エネルギ実現部４３で実行される処理である。 FIG. 5 shows a control flow of arithmetic processing for ignition control in the first embodiment. Step S501 is a process executed by the target ignition total energy calculator 41 in FIG. 4, and step S502 is a process executed by the ignition timing flow velocity calculator 42. Furthermore, step S503 is a process executed by the target ignition energy realization section 43 .
　［ステップＳ５０１］
　ステップＳ５０１では、目標点火トータルエネルギを算出する。目標点火トータルエネルギは、例えば、混合気の当量比を基に算出する基準エネルギ、ＥＧＲ率に応じたエネルギ量補正のための補正係数、点火時期の圧力に応じたエネルギ量補正のための補正係数、点火時期の温度に応じたエネルギ量補正のための補正係数、の積で算出することができる。 [Step S501]
In step S501, a target ignition total energy is calculated. The target ignition total energy is, for example, a reference energy calculated based on the equivalence ratio of the air-fuel mixture, a correction coefficient for correcting the energy amount according to the EGR rate, and a correction coefficient for correcting the energy amount according to the ignition timing pressure. , and a correction coefficient for correcting the amount of energy according to the temperature of the ignition timing.
　続いて図６Ａ乃至６Ｄを用いて、当量比と基準エネルギの関係６１、ＥＧＲ率と補正係数の関係６２、点火時期圧力と補正係数の関係６３、点火時期温度と補正係数の関係６４、を説明する。 Next, with reference to FIGS. 6A to 6D, a relationship 61 between the equivalence ratio and the reference energy, a relationship 62 between the EGR rate and the correction coefficient, a relationship 63 between the ignition timing pressure and the correction coefficient, and a relationship 64 between the ignition timing temperature and the correction coefficient will be explained. do.
　特定の当量比範囲で着火に必要となるエネルギが最小化することが知られている。特定の当量比範囲は、燃料種や酸化剤の種類によって異なるが、ガソリンの場合は、量論混合比（ストイキオメトリ）に近い条件で最小化する。このため、基準エネルギは、当量比に対して下に凸の特性を持つような特性をしている（図６Ａ）。 It is known that the energy required for ignition is minimized in a specific equivalence ratio range. The specific equivalence ratio range varies depending on the fuel type and oxidant type, but in the case of gasoline, it is minimized under conditions close to the stoichiometric mixture ratio (stoichiometry). Therefore, the reference energy has a downwardly convex characteristic with respect to the equivalence ratio (FIG. 6A).
　同一トルク条件を想定した場合、ＥＧＲ率の増加に伴い、点火プラグギャップ間に存在する混合気の質量や熱容量が増加する。この結果、点火コイル１６が発生するエネルギが同一であっても、ＥＧＲ率の増加に伴い、混合気の到達温度が下がる。同一の温度条件に到達させるためには、ＥＧＲ率の増加に応じてエネルギ量を増加させる必要がある。このため、ＥＧＲ率の増加に伴い補正係数は増加する特性（正の相関）をしている（図６Ｂ）。 Assuming the same torque conditions, the mass and heat capacity of the air-fuel mixture existing between the spark plug gaps increase as the EGR rate increases. As a result, even if the energy generated by the ignition coil 16 is the same, the attained temperature of the air-fuel mixture decreases as the EGR rate increases. In order to reach the same temperature conditions, it is necessary to increase the amount of energy as the EGR rate increases. Therefore, there is a characteristic (positive correlation) that the correction coefficient increases as the EGR rate increases (FIG. 6B).
　圧力の増加に伴う密度の変化は、点火プラグギャップ間に存在する混合気の質量や熱容量の増加を引き起こす。このため、圧力の異なる条件で、同一の温度条件に到達させるためには、圧力の増加に応じてエネルギ量を増加させる必要がある。このため、点火時期の圧力の増加に伴い補正係数は増加する特性（正の相関）をしている（図６Ｃ）。 The change in density that accompanies the increase in pressure causes an increase in the mass and heat capacity of the air-fuel mixture that exists between the spark plug gaps. Therefore, in order to reach the same temperature condition under different pressure conditions, it is necessary to increase the amount of energy as the pressure increases. Therefore, there is a characteristic (positive correlation) that the correction coefficient increases as the ignition timing pressure increases (Fig. 6C).
　点火コイル１６によるエネルギ供給によりプラグギャップ間の混合気を所定の温度に到達させることを考えると、点火前の温度が高いほど、供給する必要のある温度が少なくて良いことは明らかである。このため、点火時期における温度が高いほど、補正係数は減少する特性（負の相関）をしている（図６Ｄ）。 Considering that the supply of energy by the ignition coil 16 causes the air-fuel mixture in the plug gap to reach a predetermined temperature, it is clear that the higher the temperature before ignition, the lower the temperature that needs to be supplied. Therefore, the higher the temperature at the ignition timing, the smaller the correction coefficient (negative correlation) (Fig. 6D).
　図６Ａ乃至６Ｄに示す特性を、予め実験やシミュレーションによりマップ化することで、図５のステップＳ５０１にて目標点火トータルエネルギを算出できる。当量比と基準エネルギの関係、ＥＧＲ率、圧力、温度と基準エネルギの関係と逆の特性を持つ指標として層流燃焼速度がある。 By mapping the characteristics shown in FIGS. 6A to 6D in advance through experiments and simulations, the target ignition total energy can be calculated in step S501 of FIG. There is a laminar combustion velocity as an index having characteristics opposite to the relationship between the equivalence ratio and the reference energy and the relationship between the EGR rate, pressure, temperature and the reference energy.
　層流燃焼速度は、混合気に着火した際に火炎が伝播する速度を示す指標であり、特定の当量比に対して最大値を持ち、ＥＧＲ率の増加と共に減少する特性（負の相関）を示し、圧力の増加とともに減少する特性（負の相関）を示し、温度の増加と共に増加する特性（正の相関）を示す。この関係から、式（１）のような関係を実験、シミュレーションにより構築し、目標点火トータルエネルギＥの算出に用いることもできる。
　Ｅ＝Ａ－Ｂ×（ＳＬ÷ＳＬ０）・・・（１） The laminar combustion velocity is an index that indicates the speed at which a flame propagates when an air-fuel mixture is ignited. , exhibiting the property of decreasing with increasing pressure (negative correlation) and exhibiting the property of increasing with increasing temperature (positive correlation). From this relationship, a relationship such as Equation (1) can be constructed through experiments and simulations, and used to calculate the target ignition total energy E.
E=AB×(SL÷SL0) (1)
　ここで、Ａ、Ｂは正の数であり、エンジンの特性に応じて、実験やシミュレーションにより適合が必要となるパラメータである。また、ＳＬは、点火時期の温度、圧力、当量比、及びＥＧＲ率に基づき決まる混合気の層流燃焼速度であり、ＳＬ０は基準条件の層流燃焼速度である。 Here, A and B are positive numbers, and are parameters that need to be adapted through experiments and simulations according to the characteristics of the engine. SL is the laminar combustion speed of the air-fuel mixture determined based on the ignition timing temperature, pressure, equivalence ratio, and EGR rate, and SL0 is the laminar combustion speed under the reference condition.
　例えば基準条件としては、大気温度、大気圧力条件下における量論混合比、ＥＧＲ率０％の条件を選定すればよい。また、層流燃焼速度ＳＬは、実験により予め取得する、又は、既存の提案されている式を用いても良い。式（１）において層流燃焼速度の項にはマイナスが掛けられているため、式（１）で算出した目標点火トータルエネルギＥは、特定の当量比に対して最小値を持つ、ＥＧＲ率に対して正の相関を持つ、圧力に対して正の相関を持つ、温度に対して負の相関を持つ、といった特性を満足する。 For example, as a reference condition, a stoichiometric mixture ratio under atmospheric temperature and atmospheric pressure conditions and an EGR rate of 0% may be selected. Also, the laminar burning velocity SL may be obtained in advance through experiments, or may be obtained using an existing proposed formula. Since the laminar combustion velocity term in equation (1) is multiplied by a negative value, the target ignition total energy E calculated by equation (1) is the EGR rate, which has a minimum value for a specific equivalence ratio. It has a positive correlation with pressure, a positive correlation with pressure, and a negative correlation with temperature.
　以上に示すような方法で、ステップＳ５０１における目標点火トータルエネルギの算出が可能である。このように目標点火トータルエネルギを設定することで、当量比、ＥＧＲ率、点火時期の圧力、点火時期の温度、といった着火性に影響するパラメータを踏まえて適切なエネルギ目標値の設定ができる。 It is possible to calculate the target ignition total energy in step S501 by the method described above. By setting the target ignition total energy in this way, it is possible to set an appropriate energy target value based on parameters that affect ignitability, such as the equivalence ratio, EGR rate, ignition timing pressure, and ignition timing temperature.
　［ステップＳ５０２］
　ステップＳ５０２では、点火時期の点火プラグ周囲の流速を算出する。点火時期におけるプラグ周囲の流速は、エンジンの運転条件（エンジントルク、回転速度）、空気流動に関連するアクチュエータの操作量である可変バルブ操作量やタンブル制御弁開度、点火を行うタイミングである点火時期、に依存する。 [Step S502]
In step S502, the flow velocity around the spark plug at the ignition timing is calculated. The flow velocity around the plug at the ignition timing depends on the operating conditions of the engine (engine torque, rotation speed), the variable valve operation amount and tumble control valve opening, which are the operation amounts of the actuators related to air flow, and the ignition timing, which is the ignition timing. Depends on the time.
　例えば、運転条件毎の基準流速と、可変バルブ操作量、タンブル制御弁開度、点火時期、のそれぞれに基づく流速の補正係数の積により流速を求める方法が一つある。本方法による流速を求める場合、運転条件と基準流速、並びに可変バルブ操作量、タンブル制御弁開度、点火時期のそれぞれと補正係数、がどのような関係にあるか図７Ａ乃至７Ｄを用いて説明する。図７Ａ乃至７Ｄに、運転条件と基準流速の関係７１、可変バルブ操作量と補正係数の関係７２、タンブル制御弁開度と補正係数の関係７３、点火時期と補正係数の関係７４、をそれぞれ示す。 For example, there is one method of obtaining the flow velocity by multiplying the standard flow velocity for each operating condition with the flow velocity correction coefficient based on each of the variable valve operation amount, tumble control valve opening, and ignition timing. When obtaining the flow velocity by this method, the relationship between the operating conditions, the reference flow velocity, the variable valve operation amount, the tumble control valve opening, the ignition timing, and the correction coefficient will be explained using FIGS. 7A to 7D. do. 7A to 7D show a relationship 71 between the operating conditions and the reference flow velocity, a relationship 72 between the variable valve operation amount and the correction coefficient, a relationship 73 between the tumble control valve opening and the correction coefficient, and a relationship 74 between the ignition timing and the correction coefficient, respectively. .
　運転条件としては、エンジンの回転速度とエンジンの発生するトルク（エンジントルク）がある。エンジン内部に形成される渦の角速度はエンジンの回転速度に応じて変化する傾向にあり、エンジンの回転速度が大きいほど点火時期の流速が大きくなる傾向にある（回転速度と流速は正の相関がある）。エンジントルクが大きいほど、多くの空気がエンジン筒内に導入されることで、エンジン筒内での運動量が大きくなり、流速の増加が生じる可能性がある（スロットル開度と流速は正の相関がある）。 The operating conditions include the rotational speed of the engine and the torque generated by the engine (engine torque). The angular velocity of the vortex formed inside the engine tends to change according to the engine rotation speed, and the higher the engine rotation speed, the higher the ignition timing flow velocity (there is a positive correlation between the rotation speed and the flow velocity). be). The greater the engine torque, the more air is introduced into the engine cylinder, which increases the momentum in the engine cylinder and may increase the flow velocity (there is a positive correlation between throttle opening and flow velocity). be).
　一般的に、エンジントルクが大きいほど、スロットルの開度は大きい傾向にあることから、このことは、スロットル開度が大きいほど、点火時期における流速が大きいことと同意となる。このため、基準流速マップでは、エンジントルクが大きいほど流速が大きく、回転速度が大きいほど流速が大きくなるような特性をしている（図７Ａ）。 Generally speaking, the larger the engine torque, the larger the opening of the throttle. Therefore, in the reference flow velocity map, the flow velocity increases as the engine torque increases, and the flow velocity increases as the rotation speed increases (Fig. 7A).
　可変バルブの操作量に対しては、流速は所定の範囲で極大値を持つような特性を持つことから、補正係数は可変バルブの操作量の所定の範囲で極大値を持つ特性となる（流速の最大となる可変バルブ機構の操作量（基準操作量）からの実操作量の差が大きいほど、流速が小さい。基準操作量と実操作の差と流速に負の相関がある）。 Since the flow velocity has the characteristic of having a maximum value in a predetermined range with respect to the operation amount of the variable valve, the correction coefficient has a characteristic of having a maximum value in the predetermined range of the operation amount of the variable valve (flow velocity The greater the difference between the actual operation amount and the operation amount (reference operation amount) of the variable valve mechanism that maximizes the flow velocity, the smaller the flow velocity.There is a negative correlation between the difference between the reference operation amount and the actual operation amount and the flow velocity).
　具体的には可変バルブを操作し吸気弁を極端に早く閉じる場合、エンジン筒内の流れが減衰し、点火時期における流速は小さくなる。一方で、吸気弁の閉じ時期が極端に遅い場合、エンジン筒内に導入された空気のうち一部が吸気管へと吹き戻り、エンジン筒内の運動量が減少し、点火時期における流速が小さくなる。 Specifically, when the variable valve is operated to close the intake valve extremely early, the flow in the engine cylinder is attenuated and the flow velocity at the ignition timing becomes smaller. On the other hand, if the closing timing of the intake valve is extremely late, part of the air introduced into the engine cylinder will blow back into the intake pipe, reducing the momentum in the engine cylinder and reducing the flow velocity at the ignition timing. .
　このことから、可変バルブの操作量に対する流速の変化は所定の範囲で極大値を持つ特性となる（図７Ｂ）。 Therefore, the change in flow velocity with respect to the operation amount of the variable valve has a characteristic that has a maximum value within a predetermined range (Fig. 7B).
　タンブル制御弁は、同制御弁の操作により流路の一部を閉じることで、エンジン内部に流れ込むガスの流速を増加するための仕組みである。タンブル制御弁開度が大きい状態は、流路の塞ぐ量が相対的に小さいことを示す。タンブル制御弁の開度が大きい状態では、流路を塞ぐ量が相対的に小さく、点火時期における流速は小さくなり、タンブル制御弁の開度が小さい状態では、流路を塞ぐ量が相対的に大きく、点火時期における流速は大きくなる。 The tumble control valve is a mechanism that increases the flow rate of gas flowing into the engine by closing part of the flow path by operating the control valve. A large degree of opening of the tumble control valve indicates that the flow path is blocked by a relatively small amount. When the opening of the tumble control valve is large, the amount that blocks the flow path is relatively small, and the flow velocity at the ignition timing becomes small. large, and the flow velocity at the ignition timing becomes large.
　このため、タンブル制御弁の開度に対して補正係数は負の相関を持つ（図７Ｃ）。筒内に形成される渦がタンブル渦である場合、ピストン上昇に伴い渦の半径が徐々に小さくなり、プラグ周囲の流速は小さくなる傾向がある。このため、点火時期が進角するに伴い補正係数が増加する特性となる（図７Ｄ）。これに基づく補正マップには、点火時期の進角化に伴い補正係数が大きくなるように設定されている。 Therefore, the correction coefficient has a negative correlation with the degree of opening of the tumble control valve (Fig. 7C). When the vortex formed in the cylinder is a tumble vortex, the radius of the vortex gradually decreases as the piston rises, and the flow velocity around the plug tends to decrease. Therefore, the correction coefficient increases as the ignition timing advances (Fig. 7D). A correction map based on this is set so that the correction coefficient increases as the ignition timing is advanced.
　図７Ａ乃至７Ｄに示す特性を予め実験やシミュレーションによりマップ化し用いることで、ステップＳ５０２にて点火時期における点火プラグ周囲流速を算出できる。また、点火時期における点火プラグ周囲流速Ｖを算出する方法としては、次に示すようなモデル式（２）、（３）による算出もできる。
　ＲＴ＝（０．２５×Ｖａｄｖ÷π）＾（１÷３）・・・（２）
　Ｖ＝π×ＲＴ×Ｎｅ×ＮＴ÷３０・・・（３） By previously mapping the characteristics shown in FIGS. 7A to 7D through experiments and simulations and using them, the flow velocity around the spark plug at the ignition timing can be calculated in step S502. Also, as a method of calculating the spark plug peripheral flow velocity V at the ignition timing, the following model equations (2) and (3) can be used.
RT=(0.25×Vadv÷π)^(1÷3) (2)
V=π×RT×Ne×NT÷30 (3)
　ここで、Ｖａｄｖは点火時期における筒内容積（ｍ３）、ＲＴはタンブル渦径（ｍ）、Ｎｅはエンジン回転速度（ｒｐｍ）、ＮＴはタンブル比、πは円周率である。 Here, Vadv is the cylinder internal volume (m 3 ) at the ignition timing, RT is the tumble vortex diameter (m), Ne is the engine speed (rpm), NT is the tumble ratio, and π is the circumference ratio.
　タンブル比は、エンジンの特性であり、シミュレーションや実験にて予め算出し、マップ又は関数化する。タンブル制御弁の状態に応じてタンブル比をマップ化しておくことで、タンブル比の影響を反映できる。式（３）では、エンジン回転速度、点火時期の違いを表現できるが、エンジントルク、可変バルブの操作量の影響を表現できていない。これらを表現するために、図７Ａ乃至７Ｄに示した可変バルブと補正量の関係のマップから算出する補正係数との積を求めることで流速の算出ができる。 The tumble ratio is a characteristic of the engine, calculated in advance through simulations and experiments, and mapped or functioned. By mapping the tumble ratio according to the state of the tumble control valve, the influence of the tumble ratio can be reflected. Equation (3) can express differences in engine rotation speed and ignition timing, but cannot express the effects of engine torque and variable valve operation amount. In order to express these, the flow velocity can be calculated by obtaining the product of the correction coefficient calculated from the map of the relationship between the variable valve and the correction amount shown in FIGS. 7A to 7D.
　このように点火時期における流速を算出することで、運転条件、空気流動に影響する各種アクチュエータ（可変バルブ、タンブル制御弁）、点火時期、といった流速に影響するパラメータを踏まえて適切な流速を算出できる。 By calculating the flow velocity at ignition timing in this way, it is possible to calculate an appropriate flow velocity based on parameters that affect flow velocity, such as operating conditions, various actuators (variable valves, tumble control valves) that affect air flow, and ignition timing. .
　［ステップＳ５０３］
　目標点火トータルエネルギＥと流速Ｖに基づき１次コイルの通電時間、アシストタイミングを算出する。これらは、例えば、目標点火トータルエネルギの水準に応じて１次コイルの通電時間、アシストタイミングの関係をあらかじめ決めておき、決めておいた関係に基づき設定することができる。 [Step S503]
Based on the target ignition total energy E and the flow velocity V, the energization time of the primary coil and the assist timing are calculated. For example, the relationship between the energization time of the primary coil and the assist timing can be determined in advance according to the level of the target ignition total energy, and can be set based on the determined relationship.
　図８Ａ及び８Ｂに、目標点火トータルエネルギと流速に応じた１次コイルの通電時間、アシストタイミングの関係を示す。図８Ａ及び８Ｂには目標トータルエネルギが大きい場合、目標トータルエネルギが中程度の場合、目標トータルエネルギが小さい場合、を示す。 　Figures 8A and 8B show the relationship between the energization time of the primary coil and the assist timing according to the target ignition total energy and the flow velocity. FIGS. 8A and 8B show a case where the target total energy is large, a case where the target total energy is medium, and a case where the target total energy is small.
　目標点火トータルエネルギが大きい場合は、目標点火トータルエネルギの発生を点火アシスト無しでは実現できない程度の範囲を想定した設定である。目標点火トータルエネルギが中程度の場合は、１次コイルの通電時間の設定範囲内で、流速条件によらず目標点火トータルエネルギを実現できる範囲を想定したものである。目標点火トータルエネルギが小さい場合は、流速条件が小さい条件では、１次コイルの通電時間を小さくすることで実現できる範囲を想定したものである。 When the target ignition total energy is large, the setting is based on the assumption that the target ignition total energy cannot be generated without ignition assistance. When the target ignition total energy is moderate, it is assumed that the target ignition total energy can be achieved within the setting range of the energization time of the primary coil, regardless of the flow velocity conditions. When the target ignition total energy is small, the range that can be realized by shortening the energization time of the primary coil is assumed under the condition where the flow velocity condition is small.
　目標点火トータルエネルギが大きい場合は、流速に応じてアシストタイミングを変更する。図８Ａに示すとおり、１次コイルの通電時間は流速条件によらず概ね一定に設定され、流速が大きいほど点火アシストタイミングが早期化するように設定される。 　When the target ignition total energy is large, the assist timing is changed according to the flow velocity. As shown in FIG. 8A, the energization time of the primary coil is set substantially constant regardless of the flow velocity conditions, and is set so that the greater the flow velocity, the earlier the ignition assist timing.
　これは、流速が大きいほど、点火プラグギャップ間に形成される放電路が早く伸び、放電路の再形成が行われ、一度形成された火炎へのエネルギ供給が停止してしまう時刻が早期化するからである。アシスト無しでは放電開始から早いタイミングで放電路の再形成が生じてしまい、目標点火トータルエネルギの供給が放電路の再形成前に実施できない可能性が発生する。アシストが無い場合に放電路の再形成が発生する時期に合わせて、電流をアシストすることで、放電路が再形成するタイミングを遅らせて火炎へのエネルギ共有を続けることができる。この結果、目標点火トータルエネルギが火炎に対して供給でき、着火性が向上する。 This is because the higher the flow velocity, the faster the discharge path formed between the spark plug gaps expands, the discharge path is re-formed, and the time at which the energy supply to the once-formed flame stops comes earlier. It is from. Without assistance, the discharge path will be re-formed at an early timing from the start of discharge, and there is a possibility that the target ignition total energy cannot be supplied before the discharge path is re-formed. By assisting the electric current in time with the timing at which the discharge path is reformed in the absence of the assist, the timing of the reformation of the discharge path can be delayed, and the energy sharing to the flame can be continued. As a result, the target ignition total energy can be supplied to the flame, improving ignitability.
　一方で、流速が小さい場合は、放電路の伸びが遅く、放電路の伸びが大きくなり、再形成が行われやすいタイミングが遅くなる。再形成が行われやすいタイミングに合わせてアシストを行うことで、放電路の再形成を防ぎ、継続的に加熱ができ、これにより目標点火トータルエネルギを火炎へと供給することができる。 On the other hand, when the flow velocity is low, the discharge path expands slowly, the discharge path expands more, and the timing at which the reformation is likely to occur is delayed. By performing the assist in accordance with the timing at which reformation is likely to occur, the reformation of the discharge path can be prevented, heating can be continued, and the target ignition total energy can be supplied to the flame.
　この結果、必要なタイミングにエネルギ供給ができ、着火性が向上する。また、アシストタイミングが早いと、放電初期の電流値が高い期間が続き、点火プラグ１７の摩耗進行が速くなるが、流速が遅い条件に限られるが、放電のアシストタイミングを遅く設定することで、放電初期の電流値が続くことを抑制でき、点火プラグ摩耗の抑制につながる。 As a result, energy can be supplied at the required timing, improving ignitability. Also, if the assist timing is early, the period in which the current value at the beginning of the discharge is high continues, and the wear progress of the spark plug 17 is accelerated. It is possible to suppress the continuation of the current value at the initial stage of discharge, leading to suppression of spark plug wear.
　以上の様に、点火プラグ周囲の流速に応じてアシストタイミングを操作することで、放電路の再形成の抑制による着火性向上、点火プラグ摩耗の抑制が実現できる。 As described above, by manipulating the assist timing according to the flow velocity around the spark plug, it is possible to improve ignitability and suppress wear of the spark plug by suppressing the re-formation of the discharge path.
　目標点火トータルエネルギが中程度の場合は、１次通電期間は、流速の増加に伴い大きく設定する。また、流速が小さい条件でアシストを実施し、アシストタイミングは、流速の増加に伴い早期化する。このように設定することで、所定の流速以上の条件では、アシストを用いることなく、１次コイルへの通電量の変更だけで対応する。一方で、流速が遅い条件では、２次コイル側に発生する電流の最大値を抑制し、流速が遅い条件で電流を必要とする放電後半での電流の確保ができる。これにより、流速条件によらず着火性の確保と、電流最大値の抑制による点火プラグ摩耗の抑制が可能となる。 When the target ignition total energy is medium, the primary energization period is set larger as the flow velocity increases. Also, the assist is performed under the condition that the flow velocity is small, and the assist timing is advanced as the flow velocity increases. By setting in this way, when the flow velocity is equal to or higher than a predetermined value, only the amount of energization to the primary coil is changed without using an assist. On the other hand, when the flow velocity is slow, the maximum value of the current generated in the secondary coil can be suppressed, and the current can be secured in the latter half of the discharge when the current is required under the condition where the flow velocity is slow. As a result, it is possible to ensure ignitability regardless of flow velocity conditions, and to suppress spark plug wear by suppressing the maximum current value.
　目標点火トータルエネルギが小さい場合は、流速が大きいほど一次コイルの通電量を大きくし、流速が小さいほど１次コイルの通電量を小さくする。このように設定することで、流速が早い条件では、放電後の前半で高い電流が必要となる目標を満たし、流速が遅い条件では、放電後前半の電流が不要という無駄を避けた設定ができる。ただし、１次通電量は、２次側で絶縁破壊電圧を生じるために最低限必要となる通電時間があるため、これを超えて短くすることはできない。 When the target ignition total energy is small, the larger the flow velocity, the larger the energization amount of the primary coil, and the smaller the flow velocity, the smaller the energization amount of the primary coil. By setting in this way, under conditions where the flow velocity is high, a high current is required in the first half after discharge. . However, the amount of primary energization cannot be shortened beyond the minimum required energization time for generating a dielectric breakdown voltage on the secondary side.
　図９に以上に示した処理の結果例を示す。上からエンジン回転速度、点火時期の流速、１次コイル通電期間、アシストタイミング（３次コイル通電開始時期）、及び１次コイル通電期間と電流アシストにより実現される電流波形を示す。図９では時間の経過とともにエンジン回転速度が増加する状況にあり、図中では４水準の回転速度における結果を示している。 FIG. 9 shows an example of the results of the above processing. From the top, the engine speed, flow rate at ignition timing, primary coil energization period, assist timing (tertiary coil energization start timing), and current waveform realized by the primary coil energization period and current assist are shown. In FIG. 9, the engine speed increases with the passage of time, and the figure shows the results at four levels of speed.
　左から回転速度の水準を１水準目、２水準目、３水準目、４水準目、と示す。１水準目から２水準目の回転速度変化に伴う流速変化の結果、１水準目に比べて１次コイル通電期間が増加し、電流波形の最大電流が増加している。さらに、３水準目に移行した際には、３次コイルの通電が行われる。回転速度が４水準目に移行した際には、回転速度が３水準目に回転速度条件の際に比べて、３次コイルの通電タイミングが早期化している。 From the left, the rotation speed levels are shown as 1st level, 2nd level, 3rd level, and 4th level. As a result of the change in flow velocity accompanying the change in rotation speed from the first level to the second level, the primary coil energization period is increased compared to the first level, and the maximum current of the current waveform is increased. Furthermore, when the level shifts to the third level, the tertiary coil is energized. When the rotational speed shifts to the fourth level, the energization timing of the tertiary coil is earlier than when the rotational speed is at the third level.
　エンジンの回転速度に対する点火時期の流速変化は、基本的に単調な相関関係にあるため、回転速度に対する点火アシストタイミングの変化は単調変化する可能性が高い。このように、エンジンの動作条件が変化し、筒内の流速の変化が生じた場合に、流速に応じた適切なタイミングで必要なエネルギを発生させることができ、着火性の確保、無駄なエネルギ供給の抑制が実現できる。 Since the flow speed change of the ignition timing with respect to the engine speed is basically monotonically correlated, there is a high possibility that the change in the ignition assist timing with respect to the engine speed will be monotonous. In this way, when the operating conditions of the engine change and the flow velocity in the cylinder changes, the necessary energy can be generated at an appropriate timing according to the flow velocity, ensuring ignitability and eliminating wasteful energy. Suppression of supply can be realized.
　図１０に以上に示した処理の結果例を示す。上から可変バルブ操作量、点火時期の流速、１次コイル通電期間、アシストタイミング（３次コイル通電開始時期）、及び１次コイル通電期間と電流アシストにより実現される電流波形を示す。図１０では時間の経過とともに可変バルブの操作量が進角側から遅角側へと操作されている状況にあり、図中では４水準の可変バルブ操作量における結果を示している。 FIG. 10 shows an example of the results of the above processing. From the top, the variable valve operation amount, the flow rate of the ignition timing, the primary coil energization period, the assist timing (tertiary coil energization start timing), and the current waveform realized by the primary coil energization period and current assist are shown. In FIG. 10, the operation amount of the variable valve is operated from the advance side to the retard side with the passage of time, and the figure shows the results for four levels of the variable valve operation amount.
　左から可変バルブ操作量の水準を１水準目、２水準目、３水準目、４水準目、と示す。１水準目から３水準目までの変化では、流速は増加し、３水準目から４水準目への変化では流速が減少している。図７Ｂで説明した通り、可変バルブの操作量に対しては、流速は必ずしも単調変化をしない特性があることから、図１０に示すような変化となる。 From the left, the levels of the variable valve operation amount are shown as 1st level, 2nd level, 3rd level, and 4th level. In the change from the 1st level to the 3rd level, the flow velocity increases, and in the change from the 3rd level to the 4th level, the flow velocity decreases. As described with reference to FIG. 7B, the flow velocity does not necessarily change monotonically with respect to the amount of operation of the variable valve, so the change is as shown in FIG.
　可変バルブの操作量が１水準目から３水準目までの変化では、同変化に伴い流速が増加するため、電流アシストタイミングが早期化する。一方で、３水準目から４水準目の変化では、流速が減少するため、アシストタイミングが遅くなる、という変化が生じる。 When the operation amount of the variable valve changes from the 1st level to the 3rd level, the flow velocity increases with the same change, so the current assist timing is advanced. On the other hand, in the change from the 3rd level to the 4th level, since the flow velocity decreases, there occurs a change in which the assist timing is delayed.
　以上の様に、可変バルブの操作に対する点火時期の流速の変化は単調な相関関係にないため、同動作操作量に対する点火アシストタイミングの変化は単調変化しない場合がある。このように、可変バルブの動作条件が変化し、筒内の流速の変化が生じた場合に、流速に応じた適切なタイミングで必要なエネルギを発生させることができ、着火性の確保、無駄なエネルギ供給の抑制が実現できる。 As described above, since there is no monotonous correlation between the change in ignition timing flow speed and the operation of the variable valve, the change in the ignition assist timing may not change monotonically with respect to the operation amount of the same operation. In this way, when the operating conditions of the variable valve change and the flow velocity in the cylinder changes, the necessary energy can be generated at an appropriate timing according to the flow velocity, ensuring ignitability and reducing waste. Suppression of energy supply can be realized.
　図１１に以上に示した処理の結果例を示す。上からタンブル制御弁操作量、スロットル開度、点火時期の流速、１次コイル通電期間、アシストタイミング（３次コイル通電開始時期）、及び１次コイル通電期間と電流アシストにより実現される電流波形を示す。図１１では時間の経過とともにまず、タンブル制御弁の操作量が、開状態と閉状態を繰り返している。また、タンブル制御弁の操作量が前半（１、２水準目）の開状態と閉状態を行う際は、スロットル開度が一定の開度に維持されており、後半（３、４水準目）の開状態と閉状態を行う際には、スロットル開度が大きくなっている。 FIG. 11 shows an example of the results of the processing described above. From the top, the tumble control valve operation amount, throttle opening, ignition timing flow rate, primary coil energization period, assist timing (tertiary coil energization start timing), and current waveform realized by primary coil energization period and current assist show. In FIG. 11, first, the operation amount of the tumble control valve alternates between the open state and the closed state as time elapses. In addition, when the operation amount of the tumble control valve changes between the open state and the closed state in the first half (1st and 2nd levels), the throttle opening is maintained at a constant opening, and in the second half (3rd and 4th levels) , the throttle opening is large.
　また、可変バルブの操作量が進角側から遅角側へと操作されている状況にあり、図中では４水準の可変バルブ操作量における結果を示している。同一のスロットル開度の条件で、タンブル制御弁の開閉で流速を比較すると、タンブル制御弁の閉じた状態で流速が大きく、同一のタンブル制御弁の状態で比較すると、スロットル開度が大きい状態で流速が大きい。 In addition, the operation amount of the variable valve is being operated from the advance side to the retard side, and the figure shows the results for four levels of variable valve operation amounts. Comparing the flow velocity when the tumble control valve is open and closed under the same throttle opening conditions, the flow velocity is large when the tumble control valve is closed. High velocity.
　タンブル制御弁の開いた状態に比べてタンブル制御弁が閉じた状態では流速が大きくなるため、アシストタイミングが早期化する。また、スロットル開度が大きい条件では、同開度が小さい条件に比べて流速が大きくなるため、アシストタイミングが早期化する設定となる。 　The flow velocity is higher when the tumble control valve is closed than when the tumble control valve is open, so the assist timing is earlier. Also, under conditions where the throttle opening is large, the flow velocity is greater than under conditions where the throttle opening is small, so the assist timing is set to be earlier.
　このように、スロットルの動作条件が変化し、筒内の流速の変化が生じた場合に、流速に応じた適切なタイミングで必要なエネルギを発生させることができ、着火性の確保、無駄なエネルギ供給の抑制が実現できる。 In this way, when the operating conditions of the throttle change and the flow velocity in the cylinder changes, the necessary energy can be generated at an appropriate timing according to the flow velocity, ensuring ignitability and saving energy. Suppression of supply can be realized.
　図１２に以上に示した処理の結果例を示す。上から点火時期、点火時期の流速、１次コイル通電期間、アシストタイミング（３次コイル通電開始時期）、及び１次コイル通電期間と電流アシストにより実現される電流波形を示す。図１２では時間の経過とともに点火時期が進角方向に変化している。点火時期が進角方向に変化するにつれて流速が大きくなる。このため、アシストタイミングは点火時期の進角とともに早期化する設定となる。 FIG. 12 shows an example of the results of the above processing. From the top, the ignition timing, the flow rate at the ignition timing, the primary coil energization period, the assist timing (tertiary coil energization start timing), and the current waveform realized by the primary coil energization period and current assist are shown. In FIG. 12, the ignition timing changes in the advance direction with the lapse of time. The flow velocity increases as the ignition timing advances. Therefore, the assist timing is set to advance as the ignition timing advances.
　このように、点火時期が変化し、筒内の流速の変化が生じた場合に、流速に応じた適切なタイミングで必要なエネルギを発生させることができ、着火性の確保、無駄なエネルギ供給の抑制が実現できる。 In this way, when the ignition timing changes and the flow velocity in the cylinder changes, the necessary energy can be generated at an appropriate timing according to the flow velocity. Suppression can be achieved.
　続いて、図４の操作量補正部４４が実施する処理について説明する。最大発生可能エネルギ算出部４４ａは、点火コイル１６の電源電圧に基づき発生可能な最大エネルギを算出する。点火コイル１６に蓄えることができるエネルギは、点火コイル１６に接続している電源の電圧の２乗に比例する。 Next, the processing performed by the manipulated variable correction unit 44 in FIG. 4 will be described. The maximum generateable energy calculator 44 a calculates the maximum generateable energy based on the power supply voltage of the ignition coil 16 . The energy that can be stored in ignition coil 16 is proportional to the square of the voltage of the power supply connected to ignition coil 16 .
　例えば、基準を１４Ｖとすると、１２Ｖで２７％、１０Ｖで５０％だけ蓄えられるエネルギが減少する。通常、点火コイル１６の電源はバッテリであることから、コイル電源電圧の変動は生じうる。バッテリ電圧（ＶＢ）と発生可能な最大エネルギの関係は、点火コイル１６の仕様であるため予め両者の関係を調査の上、発生可能な最大エネルギを電圧のマップとして持っておけばよい。同関係から、電源電圧に応じて発生可能なエネルギ量を算出する。 For example, if the reference is 14V, the stored energy will decrease by 27% at 12V and by 50% at 10V. Since the ignition coil 16 is normally powered by a battery, the coil power supply voltage may fluctuate. Since the relationship between the battery voltage (VB) and the maximum energy that can be generated depends on the specifications of the ignition coil 16, the relationship between the two should be investigated in advance and the maximum energy that can be generated should be stored as a voltage map. From the same relationship, the amount of energy that can be generated according to the power supply voltage is calculated.
　目標希釈度補正部４４ｂは、算出された発生可能なエネルギ量に基づき、希釈度（ＥＧＲ率や空燃比）を補正する制御を行う。 The target dilution correction unit 44b performs control to correct the dilution (EGR rate and air-fuel ratio) based on the calculated amount of energy that can be generated.
　図１３を用いて、目標希釈度補正部４４ｂで実行する処理を説明する。最初に、ガス燃料比（Ｇ／Ｆ）と実効Ｇ／Ｆを説明する。Ｇ／Ｆは、混合気中の燃料以外のガス成分（空気、ＥＧＲガス、水分（湿度分））の質量と燃料の質量の比である。例えば、Ｇ／Ｆが大きいほど着火が不安定になりやすい。 The processing executed by the target dilution correction unit 44b will be described using FIG. First, gas fuel ratio (G/F) and effective G/F will be explained. G/F is the ratio of the mass of gas components (air, EGR gas, moisture (humidity)) other than fuel in the air-fuel mixture to the mass of fuel. For example, the larger the G/F, the more likely the ignition becomes unstable.
　ガスの組成によって、着火が不安定になるＧ／Ｆが異なる。ＥＧＲガスによる混合気希釈を行った際に着火が不安定になるＧ／Ｆは、空気による混合気希釈を行った際に着火が不安定になるＧ／Ｆに比べて小さい。これは、空気は酸素を含むため、ＥＧＲガスに比べて反応性が高いために生じると考える。このように着火性に与える影響が異なるＥＧＲガスと空気を同一の指標で取り扱うため、実効Ｇ／Ｆを定義する。例えば、実効Ｇ／Ｆを次の式（４）で定義する。
　実効Ｇ／Ｆ＝（Ａ／Ｆ）×（１＋α×ＥＧＲ率）・・・（４） G/F at which ignition becomes unstable differs depending on the gas composition. The G/F at which ignition becomes unstable when the mixture is diluted with EGR gas is smaller than the G/F at which ignition becomes unstable when the mixture is diluted with air. This is thought to occur because air contains oxygen and is therefore more reactive than EGR gas. Effective G/F is defined in order to handle EGR gas and air, which have different effects on ignitability, with the same index. For example, the effective G/F is defined by the following equation (4).
Effective G/F=(A/F)×(1+α×EGR rate) (4)
　ここで、αは３程度の数値になる。通常のＧ／Ｆではαは１である。この式は、ＥＧＲガス１ｇが着火性に与える影響は、空気α（ｇ）分と同等であることを意図したものである。 Here, α is a numerical value of about 3. α is 1 in a normal G/F. This formula intends that the effect of 1 g of EGR gas on ignitability is equivalent to that of air α (g).
　［ステップＳ１３０１］
　最大発生可能エネルギ算出部４４ａにて算出した最大発生可能エネルギに基づき実現可能な実効（Ｇ／Ｆ）を算出する。コイル発生エネルギと実現可能な実効Ｇ／Ｆの関係はあらかじめ試験やシミュレーションで関係性を調査したうえで、マップ化しておき、制御装置上では、同マップと最大発生可能エネルギに基づき実現可能な実効Ｇ／Ｆを算出する。以下では、実現可能な実効Ｇ／Ｆは上限Ｇ／Ｆとする。 [Step S1301]
A realizable effective (G/F) is calculated based on the maximum possible energy calculated by the maximum possible energy calculation unit 44a. The relationship between the coil generated energy and the achievable effective G/F is investigated in advance by tests and simulations, and then mapped. Calculate G/F. In the following, the realizable effective G/F is the upper limit G/F.
　［ステップＳ１３０２］
　排気Ａ／Ｆ、ＥＧＲ率と、式（４）から算出される現時点における実効Ｇ／Ｆ（現実効Ｇ／Ｆ）がステップＳ１３０１で算出した上限Ｇ／Ｆよりも小さいか判断する。上限Ｇ／Ｆよりも現実効Ｇ／Ｆが小さい場合は、ステップＳ１３０７に進む。上限Ｇ／Ｆよりも現実効Ｇ／Ｆが大きい場合は、ステップＳ１３０３に進む。 [Step S1302]
It is determined whether the current effective G/F (actual effective G/F) calculated from the exhaust A/F, EGR rate, and equation (4) is smaller than the upper limit G/F calculated in step S1301. If the actual effective G/F is smaller than the upper limit G/F, the process proceeds to step S1307. If the actual effective G/F is larger than the upper limit G/F, the process proceeds to step S1303.
　［ステップＳ１３０３］
　排気Ａ／Ｆ（現Ａ／Ｆ）がリーンＡ／Ｆ下限よりも大きいか判断する。現Ａ／ＦがリーンＡ／Ｆ下限よりも大きい場合、ステップＳ１３０４に進む。一方で、現Ａ／ＦがリーンＡ／Ｆ下限よりも小さい場合、ステップＳ１３０６に進む。なお、この判定は、現在、リーン燃焼を実行しているかを判断することと同じである。 [Step S1303]
It is determined whether the exhaust A/F (current A/F) is greater than the lean A/F lower limit. If the current A/F is greater than the lean A/F lower limit, the process proceeds to step S1304. On the other hand, if the current A/F is smaller than the lean A/F lower limit, the process proceeds to step S1306. This determination is the same as determining whether lean combustion is currently being performed.
　具体的には、現Ａ／Ｆがリーン下限よりも大きい場合は、リーン燃焼を実行している場合と考える。逆に、現Ａ／ＦがリーンＡ／Ｆ下限よりも小さいのであれば、リーン燃焼を実行していない（ストイキ燃焼を実行している）場合と理解する。 Specifically, when the current A/F is greater than the lean lower limit, it is assumed that lean combustion is being performed. Conversely, if the current A/F is smaller than the lean A/F lower limit, it is understood that lean combustion is not being executed (stoichiometric combustion is being executed).
　［ステップＳ１３０４］
　上限Ｇ／Ｆが、リーン燃焼運転で許容されるＡ／Ｆの最小値（リーンＡ／Ｆ下限）よりも大きいか判断する。上限Ｇ／ＦがリーンＡ／Ｆ下限より大きい場合、つまり、リーンＡ／Ｆ下限を超えたＡ／Ｆが設定でき、リーン燃焼で運転が可能な場合は、ステップＳ１３０５に進む。 [Step S1304]
It is determined whether the upper limit G/F is greater than the minimum value of A/F (lean A/F lower limit) allowed for lean burn operation. If the upper limit G/F is greater than the lean A/F lower limit, that is, if an A/F exceeding the lean A/F lower limit can be set and lean combustion operation is possible, the process proceeds to step S1305.
　［ステップＳ１３０５］
　目標ＥＧＲ率を以下の関係式（５）から設定し、目標Ａ／ＦをリーンＡ／Ｆ下限に設定する。
　目標ＥＧＲ率＝（上限Ｇ／Ｆ－リーンＡ／Ｆ下限）÷α・・・（５） [Step S1305]
The target EGR rate is set from the following relational expression (5), and the target A/F is set to the lean A/F lower limit.
Target EGR rate = (upper limit G/F - lean A/F lower limit) ÷ α (5)
　目標値の変更が必要な状況であるため、できるだけＧ／Ｆを大きく設定し、燃焼温度を下げるため、希釈を空気のみで行う設定としてもよい（目標ＥＧＲ率＝０）。 Since the target value needs to be changed, the G/F may be set as large as possible, and dilution may be performed only with air in order to lower the combustion temperature (target EGR rate = 0).
　［ステップＳ１３０６］
　目標空燃比をストイキ空燃比に設定し、目標ＥＧＲ率を以下の関係式（６）から設定する。
　目標ＥＧＲ率＝（上限Ｇ／Ｆ－ストイキＡ／Ｆ）÷α・・・（６） [Step S1306]
The target air-fuel ratio is set to the stoichiometric air-fuel ratio, and the target EGR rate is set from the following relational expression (6).
Target EGR rate = (upper limit G/F - stoichiometric A/F) ÷ α (6)
　なお、図１３のＳ１３０６のＡ／Ｆｓｔは、ストイキＡ／Ｆ（ストイキ空燃比）を表す。 Note that A/Fst in S1306 of FIG. 13 represents the stoichiometric A/F (stoichiometric air-fuel ratio).
　［ステップＳ１３０７］
　目標ＥＧＲ率、目標Ａ／Ｆともに維持する。 [Step S1307]
Both the target EGR rate and target A/F are maintained.
　図１３に示した処理を実行した場合のＥＧＲ率、Ａ／Ｆの動きを図１４に示す。図１４は上から、点火コイル１６の電源電圧、最大発生可能エネルギ、実効Ｇ／Ｆ、Ａ／Ｆ、ＥＧＲ率を示す。点火コイル１６の電源電圧の減少に伴い最大発生可能エネルギが減少する。実効Ｇ／Ｆ及びＡ／Ｆには最大発生可能エネルギの変化に伴う上限Ｇ／Ｆの変化が破線で示されている。 FIG. 14 shows the EGR rate and A/F movement when the processing shown in FIG. 13 is executed. FIG. 14 shows, from the top, the power supply voltage of the ignition coil 16, maximum generateable energy, effective G/F, A/F, and EGR rate. As the power supply voltage of the ignition coil 16 decreases, the maximum generateable energy decreases. The dashed lines in the effective G/F and A/F indicate changes in the upper limit G/F associated with changes in the maximum generateable energy.
　時刻ｔ１で、上限Ｇ／Ｆが実効Ｇ／Ｆを下回り始める。この時点でのＡ／Ｆ、リーン限界Ａ／Ｆ（Ａ／Ｆグラフ上の一点鎖線）との関係から、リーン燃焼設定を維持しつつ、Ａ／Ｆ目標値がリーンＡ／Ｆ下限に設定される。また目標ＥＧＲ率が上限Ｇ／Ｆを満たすように設定される。このような目標設定を満足するように、各種アクチュエータ（スロットルバルブ、ＥＧＲバルブ）が操作されることでＡ／Ｆ、ＥＧＲ率が変化する。 At time t1, the upper limit G/F begins to fall below the effective G/F. Based on the relationship between the A/F at this point and the lean limit A/F (one-dot chain line on the A/F graph), the A/F target value is set to the lean A/F lower limit while maintaining the lean combustion setting. be. Also, the target EGR rate is set so as to satisfy the upper limit G/F. Various actuators (throttle valve, EGR valve) are operated to change the A/F and the EGR rate so as to satisfy such target setting.
　具体的には、時刻ｔ１でＡ／ＦがリーンＡ／Ｆ下限になるのと合わせ、ＥＧＲ率がＡ／Ｆの減少に合わせて変化した上で、上限Ｇ／Ｆの変化に合わせて時刻ｔ２まで減少を続ける。時刻ｔ２では、ＥＧＲ率が０％に達しており、上限Ｇ／Ｆの減少への対応がＥＧＲ率の減少で対応できない状況にある。この場合は、Ａ／Ｆの目標値をストイキＡ／Ｆ（Ａ／Ｆｓｔ）に設定し、実効Ｇ／Ｆが上限Ｇ／ＦとなるようにＥＧＲ率の目標値が設定されて各種アクチュエータが操作される。 Specifically, the A/F becomes the lean A/F lower limit at time t1, and after the EGR rate changes in accordance with the decrease in A/F, the upper limit G/F changes at time t2. continue to decrease until At time t2, the EGR rate reaches 0%, and the situation is such that the reduction in the upper limit G/F cannot be dealt with by reducing the EGR rate. In this case, the target value of A/F is set to stoichiometric A/F (A/Fst), and the target value of EGR rate is set so that the effective G/F becomes the upper limit G/F, and various actuators are operated. be done.
　以上の様に目標Ａ／Ｆや目標ＥＧＲ率を点火コイル１６が発生できるエネルギ上限に合わせて変化させることで、点火コイル１６及び電源電圧の状態に応じた適切な燃焼制御が可能となり、内燃機関の着火不良を抑制しながら、電源電圧の変化による内燃機関の効率悪化を抑制した運転ができる。 As described above, by changing the target A/F and the target EGR rate in accordance with the upper limit of the energy that can be generated by the ignition coil 16, appropriate combustion control according to the states of the ignition coil 16 and the power supply voltage becomes possible, and the internal combustion engine It is possible to operate the internal combustion engine while suppressing deterioration in efficiency of the internal combustion engine due to changes in the power supply voltage while suppressing poor ignition.
　［第２の実施形態］
　図１５は、本発明の第２の実施形態の内燃機関の制御装置であるＥＣＵ２０内の点火制御部２４で実施される放電エネルギ制御の概要を示す制御ブロックである。 [Second embodiment]
FIG. 15 is a control block showing an outline of the discharge energy control performed by the ignition control section 24 in the ECU 20, which is the control device for the internal combustion engine according to the second embodiment of the present invention.
　目標点火トータルエネルギ算出部１５１は、図４と同一である。 The target ignition total energy calculator 151 is the same as in FIG.
　目標点火エネルギ実現部１５２は、目標点火トータルエネルギ量と要求トルクと、回転速度、可変バルブ、タンブル制御弁の操作量及び点火時期に基づいて、点火プラグ１７の操作量を決める。基本電流波形を決める１次コイルの通電期間と、アシストのタイミング、期間を設定算出し、出力する。 The target ignition energy realization unit 152 determines the operation amount of the spark plug 17 based on the target ignition total energy amount, the required torque, the rotation speed, the operation amounts of the variable valve and the tumble control valve, and the ignition timing. The energization period of the primary coil, which determines the basic current waveform, and the timing and period of the assist are set, calculated, and output.
　図１６は、第１の実施形態における点火制御のための演算処理の制御フローを示す。ステップＳ１６０１は、図１５の目標点火トータルエネルギ算出部１５１で実行される処理であり、ステップＳ１６０２は目標点火エネルギ実現部１５２で実行される処理である。 FIG. 16 shows a control flow of arithmetic processing for ignition control in the first embodiment. Step S1601 is a process executed by target ignition total energy calculation section 151 in FIG. 15, and step S1602 is a process executed by target ignition energy realization section 152. FIG.
　［ステップＳ１６０１］
　ステップＳ１６０１の処理は、図５のステップＳ５０１と同一の処理である。 [Step S1601]
The processing of step S1601 is the same as that of step S501 in FIG.
　［ステップＳ１６０２］
　ステップＳ１６０２では、アシスト要否を判定する。例えば、目標点火トータルエネルギと運転条件毎に設定される１次電流の通電期間の基本設定からアシスト要否を判定する。本判定のために、運転条件として、エンジントルク、回転速度、また希釈度に応じた１次コイルの通電期間をマップ化しておき、同マップから現在の運転条件、希釈度に応じた１次コイルの通電量を決める。 [Step S1602]
In step S1602, it is determined whether assistance is required. For example, the necessity of assistance is determined from the target ignition total energy and the basic setting of the primary current supply period set for each operating condition. For this determination, as operating conditions, the engine torque, rotation speed, and primary coil energization period according to the dilution are mapped, and from the map, the current operating conditions and the primary coil according to the dilution determine the amount of current applied to the
　続いて、同通電量と電源電圧に応じた１次コイルの通電のみで点火コイル１６で発生可能なエネルギをマップ化しておくことで、１次コイルの通電により発生するエネルギを算出する。さらに、算出したエネルギが目標点火トータルエネルギを満足するか判定する。満足できないと判断した場合は、アシスト要、満足できる場合は、アシスト不要と判断する。他には、運転条件、希釈度毎にアシスト要否をマップ化しておき、同マップと実際の運転条件、希釈度に基づきアシスト要否を判断してもよい。 Next, the energy generated by the energization of the primary coil is calculated by mapping the energy that can be generated by the ignition coil 16 only by energizing the primary coil according to the same energization amount and the power supply voltage. Furthermore, it is determined whether the calculated energy satisfies the target ignition total energy. If it is determined that it is not satisfied, it is determined that assistance is required, and if it is determined that it is satisfied, it is determined that assistance is not required. Alternatively, the need for assistance may be mapped for each operating condition and degree of dilution, and the need for assistance may be determined based on the map, actual operating conditions, and degree of dilution.
　［ステップＳ１６０３］
　ステップＳ１６０３では、ステップＳ１６０２でアシスト要と判断した場合、アクチュエータの操作量からアシストタイミングを算出する。 [Step S1603]
In step S1603, when it is determined in step S1602 that assistance is required, an assist timing is calculated from the operation amount of the actuator.
　アシストタイミングは、点火時期におけるプラグ周囲の流速に応じた設定が必要である。本実施形態では、流速の推定は行わず、流速とアクチュエータの相関関係に応じたアシストタイミングの操作を行う。例えば、運転条件毎の基準アシスト遅れと、可変バルブ操作量、タンブル制御弁開度、点火時期、のそれぞれに基づくアシスト遅れの補正係数の積によりアシストタイミングを求める方法が一つある。 　The assist timing must be set according to the flow velocity around the plug at the ignition timing. In this embodiment, the flow velocity is not estimated, and the assist timing is operated according to the correlation between the flow velocity and the actuator. For example, there is a method of finding the assist timing by multiplying the standard assist delay for each operating condition and the assist delay correction coefficient based on each of the variable valve operation amount, the tumble control valve opening, and the ignition timing.
　本方法によるアシスト遅れを求める場合、運転条件と基準アシスト遅れ、並びに可変バルブ操作量、タンブル制御弁開度、点火時期のそれぞれと補正係数、がどのような関係にあるか図１７Ａ乃至１７Ｄを用いて説明する。図１７Ａ乃至１７Ｄには、運転条件と基準アシスト遅れの関係１７１、可変バルブ操作量と補正係数の関係１７２、タンブル制御弁開度と補正係数の関係１７３、点火時期と補正係数の関係１７４、を示す。 17A to 17D are used to determine the relationship between the operating conditions, the reference assist delay, the variable valve operation amount, the tumble control valve opening, and the ignition timing, and the correction coefficient when obtaining the assist delay by this method. to explain. 17A to 17D show a relationship 171 between the operating conditions and the reference assist delay, a relationship 172 between the variable valve operation amount and the correction coefficient, a relationship 173 between the tumble control valve opening and the correction coefficient, and a relation 174 between the ignition timing and the correction coefficient. show.
　運転条件としては、エンジンの回転速度とエンジンの発生するトルク（エンジントルク）がある。エンジン内部に形成される渦の角速度はエンジンの回転速度に応じて変化する傾向にあり、エンジンの回転速度が大きいほど点火時期の流速が大きくなる傾向にある。エンジントルクが大きいほど、多くの空気がエンジン筒内に導入されることで、エンジン筒内での運動量が大きくなり、流速の増加が生じる可能性がある。 The operating conditions include the rotational speed of the engine and the torque generated by the engine (engine torque). The angular velocity of the vortex formed inside the engine tends to change according to the rotational speed of the engine, and the higher the engine rotational speed, the greater the flow velocity at ignition timing. The greater the engine torque, the more air is introduced into the engine cylinder, which may increase the momentum in the engine cylinder and increase the flow velocity.
　なお、一般的に、エンジントルクが大きいほど、スロットルの開度は大きい傾向にあることから、このことは、スロットル開度が大きいほど、点火時期における流速が大きいことと同意となる。このため、基準アシスト遅れは、エンジントルクが大きいほど小さく（負の相関）、回転速度が大きいほど小さく（負の相関）なるような特性をしている（図１７Ａ）。 In general, the larger the engine torque, the larger the opening of the throttle. Therefore, the reference assist delay has a characteristic that it becomes smaller (negative correlation) as the engine torque increases and becomes smaller (negative correlation) as the rotational speed increases (Fig. 17A).
　可変バルブの操作量に対しては、流速は所定の範囲で極大値を持つような特性を持つことから、アシスト遅れの補正係数は可変バルブの操作量の所定の範囲で極小値を持つ特性となる。流速が最大となる可変バルブ機構の操作量（基準操作量）からの実操作量の差が大きいほど、アシスト遅れが大きくなる。つまり、基準操作量と実操作の差とアシスト遅れに正の相関がある。 Since the flow velocity has a characteristic of having a maximum value in a given range with respect to the operation amount of the variable valve, the assist delay correction coefficient has a characteristic of having a minimum value in a given range of the operation amount of the variable valve. Become. The greater the difference between the actual operation amount and the operation amount (reference operation amount) of the variable valve mechanism that maximizes the flow velocity, the greater the assist delay. That is, there is a positive correlation between the difference between the reference operation amount and the actual operation and the assist delay.
　例えば可変バルブを操作し吸気弁を極端に早く閉じる場合、エンジン筒内の流れが減衰し、点火時期における流速は小さくなるためアシスト遅れは小さくなる。また、吸気弁の閉じ時期が極端に遅い場合、エンジン筒内に導入された空気のうち一部が吸気管へと吹き戻り、エンジン筒内の運動量が減少し、点火時期における流速が小さくなるためアシスト遅れは小さくなる。 For example, when the variable valve is operated to close the intake valve extremely early, the flow in the engine cylinder is damped, and the flow velocity at the ignition timing becomes smaller, so the assist delay becomes smaller. Also, if the closing timing of the intake valve is extremely late, part of the air introduced into the engine cylinder will blow back into the intake pipe, reducing the momentum in the engine cylinder and reducing the flow velocity at the ignition timing. Assist delay becomes small.
　このことから、可変バルブの操作量に対するアシスト遅れの変化は所定の範囲で極小値を持つ特性となる（図１７Ｂ）。 Therefore, the change in the assist delay with respect to the operation amount of the variable valve has a characteristic that has a minimum value within a predetermined range (Fig. 17B).
　タンブル制御弁は、同制御弁の操作により流路の一部を閉じることで、エンジン内部に流れ込むガスの流速を増加するための仕組みである。タンブル制御弁開度が大きい状態は、流路の塞ぐ量が相対的に小さいことを示す。タンブル制御弁の開度が大きい状態では、流路を塞ぐ量が相対的に小さく、点火時期における流速は小さくなり、タンブル制御弁の開度が小さい状態では、流路を塞ぐ量が相対的に大きく、点火時期における流速は大きくなるためアシスト遅れは小さくなる。 The tumble control valve is a mechanism that increases the flow rate of gas flowing into the engine by closing part of the flow path by operating the control valve. A large degree of opening of the tumble control valve indicates that the flow path is blocked by a relatively small amount. When the opening of the tumble control valve is large, the amount that blocks the flow path is relatively small, and the flow velocity at the ignition timing becomes small. The assist delay becomes small because the flow velocity at the ignition timing becomes large.
　このため、タンブル制御弁の開度に対してアシスト遅れの補正係数は正の相関を持つ（図１７Ｃ）。筒内に形成される渦がタンブル渦である場合、ピストン上昇に伴い渦が減衰するため、プラグ周囲の流速は小さくなる傾向があるため、アシスト遅れは点火時期の遅角化に応じて大きくなる。このため、点火時期が進角するに伴いアシスト遅れの補正係数が減少する特性となる（図１７Ｄ）。点火時期に基づく補正マップには、点火時期の進角化に伴いアシスト遅れの補正係数が小さくなるように設定されている。 Therefore, the assist delay correction coefficient has a positive correlation with the opening of the tumble control valve (Fig. 17C). If the vortex formed in the cylinder is a tumble vortex, the vortex will attenuate as the piston rises, and the flow velocity around the plug will tend to decrease, so the assist delay will increase as the ignition timing is retarded. . Therefore, as the ignition timing advances, the assist delay correction coefficient decreases (FIG. 17D). The correction map based on the ignition timing is set so that the correction coefficient for the assist delay becomes smaller as the ignition timing is advanced.
　図１７Ａ乃至１７Ｄに示す特性を予め実験やシミュレーションによりマップ化し用いることで、ステップＳ１６０３にてアシスト遅れを算出できる。同ステップで操作した場合のアクチュエータとアシストの関係は、図９～図１２にて説明したものと同一となる。 By previously mapping the characteristics shown in FIGS. 17A to 17D through experiments and simulations and using them, the assist delay can be calculated in step S1603. The relationship between the actuator and the assist when operated in the same steps is the same as that described with reference to FIGS.
　第１及び第２の実施形態の主な特徴は、以下のようにまとめることもできる。 The main features of the first and second embodiments can also be summarized as follows.
　内燃機関の制御装置（ＥＣＵ２０、図３）のプロセッサ（ＣＰＵ２３ａ、図３）は、内燃機関の運転条件（例えば、要求トルク、回転速度）及び混合気の希釈状態（例えば、ＥＧＲ率、空燃比）に基づいて、内燃機関の筒内の混合気の点火に必要なエネルギの目標値を示す目標点火トータルエネルギを算出する（目標点火トータルエネルギ算出部４１、図４）。 The processor (CPU 23a, FIG. 3) of the control device (ECU 20, FIG. 3) of the internal combustion engine determines the operating conditions of the internal combustion engine (e.g., required torque, rotational speed) and the dilution state of the air-fuel mixture (e.g., EGR rate, air-fuel ratio). (target ignition total energy calculation unit 41, FIG. 4).
　プロセッサ（ＣＰＵ２３ａ）は、点火時期における内燃機関の筒内の混合気の流速に相関を持つ内燃機関のパラメータ（例えば、タンブル制御弁の開度、可変バルブ機構の操作量、スロットルの開度、点火時期）に基づいて、点火装置に放電電流をアシストさせるとともに、点火装置に目標点火トータルエネルギに応じた点火エネルギを発生させる（目標点火エネルギ実現部４３、図４）。 The processor (CPU 23a) calculates the parameters of the internal combustion engine (for example, the opening of the tumble control valve, the amount of operation of the variable valve mechanism, the opening of the throttle, the ignition Based on the timing), the ignition device is caused to assist the discharge current, and the ignition device is caused to generate ignition energy corresponding to the target ignition total energy (target ignition energy realization section 43, FIG. 4).
　これにより、流速に相関を持つ内燃機関のパラメータに応じて放電電流がアシストされ、放電路の再形成が抑制される。その結果、内燃機関の着火不良を抑制することができる。また、流速が遅い場合に放電電流をアシストするタイミングを遅くすることで、放電初期の放電電流を抑制することができる。その結果、点火プラグ１７の摩耗を抑制することができる。 As a result, the discharge current is assisted according to the parameters of the internal combustion engine that are correlated with the flow velocity, and the reformation of the discharge path is suppressed. As a result, ignition failure of the internal combustion engine can be suppressed. Further, by delaying the timing of assisting the discharge current when the flow velocity is slow, the discharge current at the beginning of the discharge can be suppressed. As a result, wear of the spark plug 17 can be suppressed.
　プロセッサ（ＣＰＵ２３ａ）は、例えば、内燃機関の運転条件（例えば、要求トルク、回転速度）、内燃機関の筒内の混合気の流れ状態を制御するアクチュエータの操作量（例えば、タンブル制御弁の開度、可変バルブ機構の操作量）、及び点火時期に基づいて、点火時期における前記内燃機関の筒内の混合気の流速を推定する（点火時期流速算出部４２、図４）。 The processor (CPU 23a), for example, determines the operating conditions of the internal combustion engine (e.g., required torque, rotational speed), the operation amount of an actuator that controls the flow state of the air-fuel mixture in the cylinder of the internal combustion engine (e.g., the opening of the tumble control valve , operation amount of the variable valve mechanism) and the ignition timing, the flow velocity of the air-fuel mixture in the cylinder of the internal combustion engine at the ignition timing is estimated (ignition timing flow velocity calculator 42, FIG. 4).
　流速に相関を持つ内燃機関のパラメータは、例えば、プロセッサ（ＣＰＵ２３ａ）によって推定された流速の値を示す流速推定値である。プロセッサ（ＣＰＵ２３ａ）は、流速推定値が大きくなるにつれて、放電開始タイミングから放電電流のアシストを開始するタイミングまでの時間を示すアシスト遅れを小さくする（図８Ａ、８Ｂ等）。 A parameter of the internal combustion engine that correlates with the flow velocity is, for example, a flow velocity estimated value that indicates the value of the flow velocity estimated by the processor (CPU 23a). The processor (CPU 23a) reduces the assist delay, which indicates the time from the discharge start timing to the timing at which the discharge current assist is started, as the flow velocity estimated value increases (FIGS. 8A, 8B, etc.).
　これにより、流速推定値に応じたタイミングで放電電流がアシストされる。また、筒内流速センサ（流量センサ）を用いずに、流速を推定することができる。 As a result, the discharge current is assisted at the timing according to the estimated flow velocity. Further, the flow velocity can be estimated without using an in-cylinder flow velocity sensor (flow rate sensor).
　プロセッサ（ＣＰＵ２３ａ）は、流速に相関を持つ内燃機関のパラメータ（例えば、タンブル制御弁の開度、可変バルブ機構の操作量、スロットルの開度、点火時期）の変化により流速が大きくなるにつれて、アシスト遅れを小さくする（図１７Ａ乃至１７Ｄ）。 The processor (CPU 23a) increases the flow speed due to changes in parameters of the internal combustion engine (for example, the opening of the tumble control valve, the amount of operation of the variable valve mechanism, the opening of the throttle, and the ignition timing) that are correlated with the flow speed. Decrease the delay (FIGS. 17A-17D).
　これにより、流速に相関を持つ内燃機関のパラメータに応じたタイミングで放電電流がアシストされる。 As a result, the discharge current is assisted at the timing according to the parameters of the internal combustion engine that are correlated with the flow velocity.
　流速に相関を持つ内燃機関のパラメータは、例えば、内燃機関の筒内の混合気の流れ状態を制御するアクチュエータ（例えば、タンブル制御弁、可変バルブ機構、スロットルバルブ）の操作量である。これにより、流速に相関を持つアクチュエータの操作量に応じたタイミングで放電電流がアシストされる（図１７Ａ、１７Ｂ、１７Ｃ等）。 A parameter of the internal combustion engine that correlates with the flow velocity is, for example, the manipulated variable of the actuator (eg, tumble control valve, variable valve mechanism, throttle valve) that controls the flow state of the air-fuel mixture in the cylinder of the internal combustion engine. As a result, the discharge current is assisted at the timing according to the operation amount of the actuator that correlates with the flow velocity (FIGS. 17A, 17B, 17C, etc.).
　アクチュエータは、例えば、タンブル制御弁である。プロセッサ（ＣＰＵ２３ａ）は、タンブル制御弁の開度が大きくなるにつれて、アシスト遅れを大きくする（図１７Ｃ等）。これにより、タンブル制御弁の開度に応じたタイミングで放電電流がアシストされる。 The actuator is, for example, a tumble control valve. The processor (CPU 23a) increases the assist delay as the opening of the tumble control valve increases (FIG. 17C, etc.). As a result, the discharge current is assisted at a timing corresponding to the degree of opening of the tumble control valve.
　アクチュエータは、例えば、吸気弁を閉じるタイミングを調整する可変バルブ機構（可変バルブ５、図１）である。プロセッサ（ＣＰＵ２３ａ）は、可変バルブ機構の操作量と、流速が最大となる可変バルブ機構の操作量を示す基準操作量との差が大きくなるにつれて、アシスト遅れを大きくする（図１７Ｂ等）。これにより、可変バルブ機構の操作量と基準操作量との差に応じたタイミングで放電電流がアシストされる。 The actuator is, for example, a variable valve mechanism (variable valve 5, FIG. 1) that adjusts the timing of closing the intake valve. The processor (CPU 23a) increases the assist delay as the difference between the operation amount of the variable valve mechanism and the reference operation amount indicating the operation amount of the variable valve mechanism that maximizes the flow velocity increases (FIG. 17B, etc.). Thereby, the discharge current is assisted at the timing according to the difference between the operation amount of the variable valve mechanism and the reference operation amount.
　アクチュエータは、例えば、スロットルバルブ（電子制御スロットル２、図１）である。プロセッサ（ＣＰＵ２３ａ）は、スロットルの開度（エンジントルク）が大きくなるにつれて、アシスト遅れを小さくする（図１７Ａ等）。これにより、スロットルの開度に応じたタイミングで放電電流がアシストされる。 The actuator is, for example, a throttle valve (electronic control throttle 2, Fig. 1). The processor (CPU 23a) reduces the assist delay as the throttle opening (engine torque) increases (FIG. 17A, etc.). As a result, the discharge current is assisted at a timing corresponding to the opening of the throttle.
　流速に相関を持つ前記内燃機関のパラメータは、例えば、点火時期である。プロセッサ（ＣＰＵ２３ａ）は、点火時期が進角するにつれて、アシスト遅れを小さくする（図１７Ｄ等）。これにより、点火時期に応じたタイミングで放電電流がアシストされる。 A parameter of the internal combustion engine that correlates with flow velocity is, for example, ignition timing. The processor (CPU 23a) reduces the assist delay as the ignition timing advances (FIG. 17D, etc.). As a result, the discharge current is assisted at a timing corresponding to the ignition timing.
　なお、流速に相関を持つ前記内燃機関のパラメータは、点火時期における放電プラズマの伸長速度であってもよい。流速が大きくなるほど、放電プラズマの伸長速度は大きくなる。そこで、プロセッサ（ＣＰＵ２３ａ）は、伸長速度が大きくなるにつれて、アシスト遅れを小さくする。これにより、放電プラズマの伸長速度に応じたタイミングで放電電流がアシストされる。 It should be noted that the parameter of the internal combustion engine that correlates with the flow velocity may be the expansion speed of the discharge plasma at the ignition timing. The higher the flow velocity, the higher the discharge plasma elongation velocity. Therefore, the processor (CPU 23a) reduces the assist delay as the decompression speed increases. As a result, the discharge current is assisted at a timing corresponding to the expansion speed of the discharge plasma.
　点火装置は、点火コイル１６（１次コイル、２次コイル及び３次コイル）、及び点火プラグ１７を備える（図２Ａ）。１次コイルへの通電を遮断することにより、点火プラグ１７の電極間に放電電流が流れ、放電期間内に３次コイルへ通電することにより、放電電流が増加する（図２Ｂ）。 The ignition device includes an ignition coil 16 (primary coil, secondary coil and tertiary coil) and a spark plug 17 (Fig. 2A). By interrupting the energization of the primary coil, a discharge current flows between the electrodes of the spark plug 17, and by energizing the tertiary coil during the discharge period, the discharge current increases (FIG. 2B).
　プロセッサ（ＣＰＵ２３ａ）は、図８Ａ及び８Ｂに示すように、目標点火トータルエネルギが所定範囲（目標トータルエネルギが中程度）より大きい場合（すなわち、目標トータルエネルギが大きい場合）、及び目標点火トータルエネルギが所定範囲（目標トータルエネルギが中程度）内であり、かつ流速が閾値未満である場合、１次コイルと３次コイルによって、２次コイルに目標点火トータルエネルギに相当するエネルギを発生させる。 The processor (CPU 23a), as shown in FIGS. 8A and 8B, when the target ignition total energy is larger than a predetermined range (the target total energy is medium) (that is, when the target total energy is large), and when the target ignition total energy is When the target total energy is within a predetermined range (medium target total energy) and the flow velocity is less than the threshold value, the primary coil and the tertiary coil generate energy corresponding to the target ignition total energy in the secondary coil.
　プロセッサ（ＣＰＵ２３ａ）は、目標点火トータルエネルギが所定範囲（目標トータルエネルギが中程度）内であり、かつ流速が閾値以上である場合、及び目標点火トータルエネルギが所定範囲（目標トータルエネルギが中程度）より小さい場合（すなわち、目標トータルエネルギが小さい場合）、１次コイルのみによって、２次コイルに前記目標点火トータルエネルギに相当するエネルギを発生させる（図８Ａ及び８Ｂ）。 When the target ignition total energy is within a predetermined range (target total energy is medium) and the flow velocity is equal to or greater than a threshold value, the processor (CPU 23a) determines whether the target ignition total energy is within a predetermined range (target total energy is medium). If less (ie target total energy is small), the primary coil alone will cause the secondary coil to generate energy corresponding to the target ignition total energy (FIGS. 8A and 8B).
　プロセッサ（ＣＰＵ２３ａ）は、目標点火トータルエネルギが所定範囲より大きい場合（目標トータルエネルギが大きい場合）、及び目標点火トータルエネルギが所定範囲（目標トータルエネルギが中程度）内であり、かつ流速が閾値未満である場合、流速が大きくなるにつれて３次コイルへ通電するタイミングを早くする（図８Ａ及び８Ｂ）。 If the target ignition total energy is greater than a predetermined range (the target total energy is large), the target ignition total energy is within the predetermined range (the target total energy is intermediate), and the flow velocity is less than the threshold , the timing of energizing the tertiary coil is advanced as the flow velocity increases (FIGS. 8A and 8B).
　プロセッサ（ＣＰＵ２３ａ）は、目標点火トータルエネルギが所定範囲（目標トータルエネルギが中程度）内である場合、及び目標点火トータルエネルギが所定範囲より小さい場合（目標トータルエネルギが小さい場合）、流速が大きくなるにつれて１次コイルへの通電期間を長くする。 The processor (CPU 23a) increases the flow velocity when the target ignition total energy is within a predetermined range (target total energy is medium) and when the target ignition total energy is smaller than the predetermined range (target total energy is small). The energization period to the primary coil is lengthened accordingly.
　このように点火装置の１次コイルと３次コイルへの通電を制御することで、内燃機関の着火不良を抑制しつつ、点火プラグ１７の摩耗を抑制することができる。 By controlling the energization of the primary coil and the tertiary coil of the ignition device in this way, it is possible to suppress the wear of the spark plug 17 while suppressing the ignition failure of the internal combustion engine.
　プロセッサ（ＣＰＵ２３ａ）は、点火装置の充電電源の電圧（例えば、バッテリ電圧）に基づき点火装置の最大発生可能エネルギを算出する（最大発生可能エネルギ算出部４４ａ、図４）。プロセッサ（ＣＰＵ２３ａ）は、最大発生可能エネルギが小さくなるにつれて混合気の希釈度の目標値を小さくする（目標希釈度補正部４４ｂ、図４）。これにより、電源電圧の変化による内燃機関の効率悪化を抑制することができる。 The processor (CPU 23a) calculates the maximum generateable energy of the ignition device based on the voltage (eg, battery voltage) of the charging power source of the ignition device (maximum generateable energy calculator 44a, FIG. 4). The processor (CPU 23a) decreases the target value of the dilution of the air-fuel mixture as the maximum generateable energy decreases (target dilution correction unit 44b, FIG. 4). As a result, deterioration in efficiency of the internal combustion engine due to changes in the power supply voltage can be suppressed.
　なお、本発明は上記した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、上述した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、あ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、あ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。 It should be noted that the present invention is not limited to the above-described embodiments, and includes various modifications. For example, the above-described embodiments have been described in detail in order to explain the present invention in an easy-to-understand manner, and are not necessarily limited to those having all the described configurations. Also, part of the configuration of one embodiment can be replaced with the configuration of another embodiment, and the configuration of another embodiment can be added to the configuration of one embodiment. Moreover, it is possible to add, delete, or replace part of the configuration of each embodiment with another configuration.
　また、上記の各構成、機能等は、それらの一部又は全部を、例えば集積回路で設計する等によりハードウェアで実現してもよい。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で実現してもよい。各機能を実現するプログラム、テーブル、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。 In addition, each of the above configurations, functions, etc. may be realized by hardware, for example, by designing a part or all of them with an integrated circuit. Moreover, each of the above configurations, functions, etc. may be realized by software by a processor interpreting and executing a program for realizing each function. Information such as programs, tables, and files that implement each function can be stored in a recording device such as a memory, a hard disk, an SSD (Solid State Drive), or a recording medium such as an IC card, SD card, or DVD.
　なお、本発明の実施形態は、以下の態様であってもよい。 It should be noted that the embodiment of the present invention may have the following aspects.
　（１）．点火装置を備える内燃機関を制御する内燃機関の制御装置において、前記点火装置が放電電流を放電期間中に電流をアシストする仕組みを備え、運転条件や混合気の希釈状態に基づき目標点火トータルエネルギを算出する目標点火トータルエネルギ算出部、点火時期の内燃機関内部の流速に相関を持つパラメータに基づき電流をアシストし、前記目標点火トータルエネルギを実現する目標点火エネルギ実現部、を備えることを特徴とする内燃機関の制御装置。 (1). A control device for an internal combustion engine that controls an internal combustion engine having an ignition device, wherein the ignition device has a mechanism for assisting the discharge current during the discharge period, and the target ignition total energy is determined based on the operating conditions and the dilution state of the air-fuel mixture. and a target ignition energy realization part for realizing the target ignition total energy by assisting the current based on a parameter correlated with the flow velocity inside the internal combustion engine at the ignition timing. A control device for an internal combustion engine.
　（２）．運転条件と内燃機関内部の流れ状態を制御するアクチュエータの操作量と点火時期に基づき前記点火時期における流速を推定する点火時期流速推定部を備え、前記流速に相関を持つパラメータが、前記点火時期流速推定部で推定した流速推定値、であることを特徴とする（１）の制御装置。 (2). an ignition timing flow velocity estimator for estimating a flow velocity at the ignition timing based on an operating condition and an operation amount of an actuator for controlling a flow state inside the internal combustion engine and ignition timing, wherein a parameter correlated with the flow velocity is the ignition timing flow velocity The control device according to (1), characterized in that the flow velocity estimated value estimated by the estimation unit.
　（３）．前記点火時期の流速推定値と放電開始から電流のアシストを開始するタイミングまでの時間が負の相関を持つことを特徴とする（２）の制御装置（補足：流速大→放電開始からアシスト開始までの期間小、流速小→放電開始からアシスト開始までの期間大）。 (3). The control device of (2), characterized in that the estimated value of the flow velocity of the ignition timing and the time from the start of discharge to the start of assist current have a negative correlation (Supplement: high flow velocity → from start of discharge to start of assist period is short, flow velocity is small → period from the start of discharge to the start of assist is long).
　（４）．前記流速に相関を持つパラメータが示す点火時期の内燃機関内部の流速と放電開始から電流のアシストを開始するタイミングまでの時間が負の相関を持つことを特徴とする（１）の制御装置（流速相関パラメータと操作量の一般化）。 (4). The control device (flow velocity generalization of correlation parameters and manipulated variables).
　（５）．前記流速に相関を持つパラメータが、内燃機関内部の流れ状態を制御するアクチュエータの操作量であることを特徴とする（１）、（４）の制御装置（流速相関パラメータの具体化）。 (5). The control device according to (1) or (4) (embodiment of the flow velocity correlation parameter), wherein the parameter correlated with the flow velocity is the manipulated variable of an actuator that controls the flow state inside the internal combustion engine.
　（６）．前記内部機関の流れ状態を制御するアクチュエータは、前記内燃機関の吸気管内に設けられたエンジンタンブル制御弁であり、タンブル制御弁の開度と前記アシストまでの期間が正の相関を持つことを特徴とする（５）の制御装置（タンブル制御弁の開度小（＝流速大）→アシストまでの期間小）。 (6). The actuator for controlling the flow state of the internal engine is an engine tumble control valve provided in the intake pipe of the internal combustion engine, and the degree of opening of the tumble control valve and the period until the assist are positively correlated. (5) (small opening of tumble control valve (=large flow velocity)→short period until assist).
　（７）．前記内燃機関の流れ状態を制御するアクチュエータは、前記内燃機関の可変バルブ機構であり、点火時期における流速が最も大きくなる吸気弁閉じ位置となる可変バルブ機構の操作量と実操作量の差と前記アシストまでの期間が正の相関を持つことを特徴とする（５）の制御装置（バルブ機構の基準操作量からの差大（＝流速小）→アシストまでの期間大）。 (7). The actuator for controlling the flow state of the internal combustion engine is a variable valve mechanism of the internal combustion engine. The control device of (5) characterized in that the period until the assist has a positive correlation (large difference from the reference operation amount of the valve mechanism (=small flow velocity)→long period until the assist).
　（８）．前記アクチュエータがスロットルバルブであり、前記スロットルバルブの開度と前記アシストまでの期間が負の相関を持つことを特徴とする（５）の制御装置。 (8). The control device according to (5), wherein the actuator is a throttle valve, and the degree of opening of the throttle valve and the period until the assist is negatively correlated.
　（９）．前記流速に相関を持つパラメータが、点火時期であり、点火時期の進角量と放電開始から電流のアシストを開始するタイミングまでの時間が負の相関を持つことを特徴とする（１）、（４）の制御装置（点火進角量大（＝流速大）→アシストまでの期間小）。 (9). The parameter correlated with the flow velocity is the ignition timing, and the advance amount of the ignition timing and the time from the start of discharge to the timing of starting the current assist are negatively correlated (1), ( 4) Control device (large ignition advance amount (=large flow velocity) → short period until assist).
　（１０）．前記流速に相関を持つパラメータが、点火時期における放電プラズマの伸長速度であることを特徴とする（１）、（４）の制御装置。 (10). The control device according to (1) or (4), characterized in that the parameter correlated with the flow velocity is the elongation velocity of the discharge plasma at the ignition timing.
　（１１）．前記放電プラズマの伸長速度と放電開始から電流のアシストを開始するタイミングまでの時間が負の相関を持つことを特徴とする（１０）の制御装置。 (11). The control device according to (10), characterized in that the expansion speed of the discharge plasma and the time from the start of discharge to the start of current assist have a negative correlation.
　（１２）．前記目標点火トータルエネルギは、エンジンの運転条件のパラメータ、混合気の希釈状態を示すパラメータに基づき算出され、前記運転条件のパラメータの少なくとも一つはエンジントルクと相関を持つ指標であり、前記混合気の希釈状態を示すパラメータの少なくとも一つは混合気の希釈率と相関を持つ指標であり、前記エンジントルクが大きいほど前記トータルエネルギは大きく設定され、前記希釈率が大きいほど前記トータルエネルギが大きく設定されること、を特徴とする（１）～（１１）の制御装置。 (12). The target ignition total energy is calculated based on an engine operating condition parameter and a parameter indicating the dilution state of the air-fuel mixture, at least one of the operating condition parameters is an index correlated with engine torque, and the air-fuel mixture At least one of the parameters indicating the dilution state of is an index that correlates with the dilution rate of the air-fuel mixture, the greater the engine torque, the greater the total energy is set, and the greater the dilution rate, the greater the total energy is set. The control device according to (1) to (11) characterized by:
　（１３）．アシスト前の放電電流を前記目標点火トータルエネルギと前記点火時期の内燃機関内部の流速に相関を持つパラメータに基づき操作することを特徴とする（１）～（１２）の制御装置。 (13). The control device according to any one of (1) to (12), wherein the discharge current before assist is controlled based on a parameter having a correlation with the target ignition total energy and the flow velocity inside the internal combustion engine at the ignition timing.
　（１４）．前記流速に相関を持つパラメータが示す流速と放電開始時の放電電流が正の相関を持つことを特徴とする（１３）の制御装置。 (14). The control device according to (13), characterized in that the flow velocity indicated by the parameter correlated with the flow velocity and the discharge current at the start of discharge have a positive correlation.
　（１５）．点火装置の充電電源に基づき点火装置の最大発生可能エネルギを算出する最大発生可能エネルギ算出部を備え、前記最大発生可能エネルギに基づき混合気の希釈度の目標値を補正する目標希釈度補正部を備えることを特徴とする（１）～（１４）の制御装置。 (15). a maximum possible energy calculation unit that calculates the maximum possible energy of the ignition device based on the charging power source of the ignition device; and a target dilution correction unit that corrects the target value of the mixture dilution based on the maximum possible energy. The control device according to (1) to (14), characterized by comprising:
　（１６）．前記最大発生可能エネルギと前記補正後の希釈度の目標値が正の相関を持つことを特徴とする（１５）の制御装置（最大発生可能エネルギ大→希釈度目標値大）。 (16). The control device according to (15), characterized in that the maximum possible energy and the corrected target value of dilution have a positive correlation (large maximum possible energy→large target value of dilution).
　（１）～（１６）によれば、点火時期における点火プラグ周囲の流速を考慮した上で、基本電流波形に対して適切なタイミングで電流を加算することができる。また、点火進角時に点火遅角条件から決まるシステムの要求放電エネルギから放電エネルギを減少させることが出来るので、点火コイルの発熱や、点火プラグの磨耗を抑制し、システムの耐久性を向上することができる。 According to (1) to (16), the current can be added to the basic current waveform at an appropriate timing after considering the flow velocity around the spark plug at the ignition timing. In addition, when the ignition is advanced, the discharge energy can be reduced from the required discharge energy of the system, which is determined by the ignition retard conditions, so that the heat generation of the ignition coil and the wear of the spark plug can be suppressed, and the durability of the system can be improved. can be done.
　１…エアフローセンサ、２…電子制御スロットル、４…過給機、４ａ…コンプレッサ、４ｂ…タービン、５…可変バルブ、６…吸気マニホールド、７…インタークーラ、９…空燃比センサ、１０…三元触媒、１１…電子制御ウェイストゲート弁、１２…アクセル開度センサ、１３…燃料噴射装置、１４…シリンダ、１５…排気管、１６…点火コイル、１７…点火プラグ、１８…水温センサ、１９…クランク角度センサ、２０…ＥＣＵ、２１…入力回路、２２…入出力ポート、２３ａ…ＣＰＵ、２３ｂ…ＲＯＭ、２３ｃ…ＲＡＭ、２４…点火制御部、２５…基本放電エネルギ算出部、２６…要求放電エネルギ算出部、２７…エネルギ得失算出部、２８…最終放電エネルギ算出部、２９…放電エネルギ制御部、３０…ガス燃料比Ｇ／Ｆ制御部 REFERENCE SIGNS LIST 1 airflow sensor 2 electronically controlled throttle 4 supercharger 4a compressor 4b turbine 5 variable valve 6 intake manifold 7 intercooler 9 air-fuel ratio sensor 10 ternary Catalyst 11 Electronically controlled wastegate valve 12 Accelerator opening sensor 13 Fuel injector 14 Cylinder 15 Exhaust pipe 16 Ignition coil 17 Spark plug 18 Water temperature sensor 19 Crank Angle sensor 20 ECU 21 input circuit 22 input/output port 23a CPU 23b ROM 23c RAM 24 ignition control section 25 basic discharge energy calculation section 26 required discharge energy calculation Section, 27...Energy gain/loss calculation section, 28...Final discharge energy calculation section, 29...Discharge energy control section, 30...Gas fuel ratio G/F control section

Claims (11)

  1. 　内燃機関の運転条件及び混合気の希釈状態に基づいて、前記内燃機関の筒内の混合気の点火に必要なエネルギの目標値を示す目標点火トータルエネルギを算出し、
    　点火時期における前記内燃機関の筒内の混合気の流速に相関を持つ前記内燃機関のパラメータに基づいて、点火装置に放電電流をアシストさせるとともに、前記点火装置に前記目標点火トータルエネルギに応じた点火エネルギを発生させるプロセッサを備える
    　ことを特徴とする内燃機関の制御装置。     calculating a target ignition total energy indicating a target value of energy required for ignition of an air-fuel mixture in a cylinder of the internal combustion engine, based on an operating condition of the internal combustion engine and a dilution state of the air-fuel mixture;
    Based on the parameters of the internal combustion engine that correlate with the flow velocity of the air-fuel mixture in the cylinder of the internal combustion engine at the ignition timing, the ignition device is caused to assist the discharge current, and the ignition device performs ignition according to the target ignition total energy. A control device for an internal combustion engine, comprising a processor that generates energy.
  2. 　請求項１に記載の内燃機関の制御装置であって、
    　前記プロセッサは、
    　前記内燃機関の運転条件、前記内燃機関の筒内の混合気の流れ状態を制御するアクチュエータの操作量、及び前記点火時期に基づいて、前記点火時期における前記内燃機関の筒内の混合気の流速を推定し、
    　前記流速に相関を持つ前記内燃機関のパラメータは、前記プロセッサによって推定された流速の値を示す流速推定値であり、
    　前記プロセッサは、
    　前記流速推定値が大きくなるにつれて、放電開始タイミングから放電電流のアシストを開始するタイミングまでの時間を示すアシスト遅れを小さくする
    　ことを特徴とする内燃機関の制御装置。     The control device for an internal combustion engine according to claim 1,
    The processor
    The flow rate of the air-fuel mixture in the cylinder of the internal combustion engine at the ignition timing based on the operating conditions of the internal combustion engine, the operation amount of an actuator that controls the flow state of the air-fuel mixture in the cylinder of the internal combustion engine, and the ignition timing. , and
    the parameter of the internal combustion engine correlated with the flow velocity is a flow velocity estimated value indicating the value of the flow velocity estimated by the processor;
    The processor
    A control device for an internal combustion engine, characterized in that, as the estimated flow velocity increases, an assist delay indicating a time from a discharge start timing to a discharge current assist start timing is reduced.
  3. 　請求項１に記載の内燃機関の制御装置であって、
    　前記プロセッサは、
    　前記流速に相関を持つ前記内燃機関のパラメータの変化により前記流速が大きくなるにつれて、放電開始タイミングから放電電流のアシストを開始するタイミングまでの時間を示すアシスト遅れを小さくする
    　ことを特徴とする内燃機関の制御装置。     The control device for an internal combustion engine according to claim 1,
    The processor
    An internal combustion engine characterized in that, as the flow speed increases due to changes in parameters of the internal combustion engine that correlate with the flow speed, an assist delay indicating a time from a discharge start timing to a discharge current assist start timing is reduced. controller.
  4. 　請求項３に記載の内燃機関の制御装置であって、
    　前記流速に相関を持つ前記内燃機関のパラメータは、前記内燃機関の筒内の混合気の流れ状態を制御するアクチュエータの操作量である
    　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 according to claim 3,
    A control device for an internal combustion engine, wherein the parameter of the internal combustion engine that correlates with the flow velocity is an operation amount of an actuator that controls a flow state of air-fuel mixture in a cylinder of the internal combustion engine.
  5. 　請求項４に記載の内燃機関の制御装置であって、
    　前記アクチュエータは、タンブル制御弁であり、
    　前記プロセッサは、
    　前記タンブル制御弁の開度が大きくなるにつれて、放電開始タイミングから放電電流のアシストを開始するタイミングまでの時間を示すアシスト遅れを大きくする
    　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 according to claim 4,
    the actuator is a tumble control valve,
    The processor
    A control device for an internal combustion engine, characterized in that, as the opening degree of the tumble control valve increases, an assist delay indicating a time from a discharge start timing to a discharge current assist start timing is increased.
  6. 　請求項４に記載の内燃機関の制御装置であって、
    　前記アクチュエータは、吸気弁を閉じるタイミングを調整する可変バルブ機構であり、
    　前記プロセッサは、
    　前記可変バルブ機構の操作量と、前記流速が最大となる可変バルブ機構の操作量を示す基準操作量との差が大きくなるにつれて、放電開始タイミングから放電電流のアシストを開始するタイミングまでの時間を示すアシスト遅れを大きくする
    　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 according to claim 4,
    The actuator is a variable valve mechanism that adjusts the timing of closing the intake valve,
    The processor
    As the difference between the operation amount of the variable valve mechanism and the reference operation amount indicating the operation amount of the variable valve mechanism that maximizes the flow velocity increases, the time from the discharge start timing to the discharge current assist start timing increases. A control device for an internal combustion engine, characterized by increasing an assist delay indicated.
  7. 　請求項４に記載の内燃機関の制御装置であって、
    　前記アクチュエータは、スロットルバルブであり、
    　前記プロセッサは、
    　前記スロットルバルブの開度が大きくなるにつれて、放電開始タイミングから放電電流のアシストを開始するタイミングまでの時間を示すアシスト遅れを小さくする
    　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 according to claim 4,
    the actuator is a throttle valve,
    The processor
    A control device for an internal combustion engine, characterized in that, as the opening of the throttle valve increases, an assist delay indicating a time from a discharge start timing to a discharge current assist start timing is reduced.
  8. 　請求項１に記載の内燃機関の制御装置であって、
    　前記流速に相関を持つ前記内燃機関のパラメータは、点火時期であり、
    　前記プロセッサは、
    　前記点火時期が進角するにつれて、放電開始タイミングから放電電流のアシストを開始するタイミングまでの時間を示すアシスト遅れを小さくする
    　ことを特徴とする内燃機関の制御装置。     The control device for an internal combustion engine according to claim 1,
    the parameter of the internal combustion engine that correlates with the flow velocity is ignition timing;
    The processor
    A control device for an internal combustion engine, wherein as the ignition timing advances, an assist delay indicating a time from a discharge start timing to a discharge current assist start timing is reduced.
  9. 　請求項１に記載の内燃機関の制御装置であって、
    　前記流速に相関を持つ前記内燃機関のパラメータは、
    　点火時期における放電プラズマの伸長速度であり、
    　前記プロセッサは、
    　前記伸長速度が大きくなるにつれて、放電開始タイミングから放電電流のアシストを開始するタイミングまでの時間を示すアシスト遅れを小さくする
    　ことを特徴とする内燃機関の制御装置。     The control device for an internal combustion engine according to claim 1,
    A parameter of the internal combustion engine having a correlation with the flow velocity is
    is the elongation speed of the discharge plasma at the ignition timing,
    The processor
    A control device for an internal combustion engine, characterized in that, as the extension speed increases, an assist delay indicating a time from a discharge start timing to a discharge current assist start timing is reduced.
  10. 　請求項１に記載の内燃機関の制御装置であって、
    　前記点火装置は、１次コイル、２次コイル、３次コイル、及び点火プラグを備え、
    　前記１次コイルへの通電を遮断することにより、前記点火プラグの電極間に放電電流が流れ、放電期間内に前記３次コイルへ通電することにより、前記放電電流が増加し、
    　前記プロセッサは、
    　前記目標点火トータルエネルギが所定範囲より大きい場合、及び前記目標点火トータルエネルギが前記所定範囲内であり、かつ前記流速が閾値未満である場合、前記１次コイルと前記３次コイルによって、前記２次コイルに前記目標点火トータルエネルギに相当するエネルギを発生させ、
    　前記目標点火トータルエネルギが前記所定範囲内であり、かつ前記流速が前記閾値以上である場合、及び前記目標点火トータルエネルギが前記所定範囲より小さい場合、前記１次コイルのみによって、前記２次コイルに前記目標点火トータルエネルギに相当するエネルギを発生させ、
    　前記目標点火トータルエネルギが所定範囲より大きい場合、及び前記目標点火トータルエネルギが前記所定範囲内であり、かつ前記流速が前記閾値未満である場合、前記流速が大きくなるにつれて前記３次コイルへ通電するタイミングを早くし、
    　前記目標点火トータルエネルギが所定範囲内である場合、及び前記目標点火トータルエネルギが所定範囲より小さい場合、前記流速が大きくなるにつれて前記１次コイルへの通電期間を長くする
    　ことを特徴とする内燃機関の制御装置。     The control device for an internal combustion engine according to claim 1,
    The ignition device includes a primary coil, a secondary coil, a tertiary coil, and a spark plug,
    By interrupting the energization of the primary coil, a discharge current flows between the electrodes of the spark plug, and by energizing the tertiary coil during the discharge period, the discharge current increases,
    The processor
    When the target ignition total energy is greater than a predetermined range and when the target ignition total energy is within the predetermined range and the flow velocity is less than a threshold value, the secondary coil is controlled by the primary coil and the tertiary coil. causing the coil to generate energy corresponding to the target ignition total energy;
    When the target ignition total energy is within the predetermined range and the flow velocity is equal to or greater than the threshold value, and when the target ignition total energy is smaller than the predetermined range, the secondary coil is driven by the primary coil alone. generating energy equivalent to the target ignition total energy;
    When the target ignition total energy is greater than the predetermined range and when the target ignition total energy is within the predetermined range and the flow velocity is less than the threshold value, the tertiary coil is energized as the flow velocity increases. speed up the timing
    When the target ignition total energy is within a predetermined range and when the target ignition total energy is smaller than the predetermined range, the energization period of the primary coil is lengthened as the flow velocity increases. controller.
  11. 　請求項１から１０のいずれかに記載の内燃機関の制御装置であって、
    　前記プロセッサは、
    　前記点火装置の充電電源の電圧に基づき前記点火装置の最大発生可能エネルギを算出し、前記最大発生可能エネルギが小さくなるにつれて混合気の希釈度の目標値を小さくする
    　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 according to any one of claims 1 to 10,
    The processor
    Calculating the maximum possible energy of the ignition device based on the voltage of the charging power source of the ignition device, and reducing the target value of the degree of dilution of the air-fuel mixture as the maximum possible energy becomes smaller. Control device.
PCT/JP2022/003976 2021-06-21 2022-02-02 Internal combustion engine control device WO2022269976A1 (en)

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Citations (13)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH01273838A (en) * 1988-04-26 1989-11-01 Toyota Motor Corp Air-fuel ratio controller for internal combustion engine
JP2015090133A (en) * 2013-11-07 2015-05-11 トヨタ自動車株式会社 Control system of spark ignition type internal combustion engine
JP2015166572A (en) * 2014-03-04 2015-09-24 株式会社デンソー Ignition control device for engine
JP2015175283A (en) * 2014-03-14 2015-10-05 トヨタ自動車株式会社 Control device for internal combustion engine
US20150300312A1 (en) * 2012-11-29 2015-10-22 Advanced Fuel And Ignition System, Inc. Multi-spark and continuous spark ignition module, system, and method
JP2016053312A (en) * 2014-09-03 2016-04-14 日産自動車株式会社 Internal combustion engine igniter and internal combustion engine ignition method
JP2016217190A (en) * 2015-05-15 2016-12-22 株式会社日本自動車部品総合研究所 Ignition device
JP2017002791A (en) * 2015-06-09 2017-01-05 株式会社日本自動車部品総合研究所 Ignition control device
JP2017190677A (en) * 2016-04-11 2017-10-19 株式会社Ｓｏｋｅｎ Control device of internal combustion engine
WO2019181293A1 (en) * 2018-03-20 2019-09-26 日立オートモティブシステムズ株式会社 Internal combustion engine control device
WO2020121375A1 (en) * 2018-12-10 2020-06-18 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
WO2020235219A1 (en) * 2019-05-23 2020-11-26 日立オートモティブシステムズ株式会社 Control device for internal combustion engine
JP2021092226A (en) * 2021-03-18 2021-06-17 株式会社Ｓｏｋｅｎ Ignition control device of internal combustion engine

Patent Citations (13)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH01273838A (en) * 1988-04-26 1989-11-01 Toyota Motor Corp Air-fuel ratio controller for internal combustion engine
US20150300312A1 (en) * 2012-11-29 2015-10-22 Advanced Fuel And Ignition System, Inc. Multi-spark and continuous spark ignition module, system, and method
JP2015090133A (en) * 2013-11-07 2015-05-11 トヨタ自動車株式会社 Control system of spark ignition type internal combustion engine
JP2015166572A (en) * 2014-03-04 2015-09-24 株式会社デンソー Ignition control device for engine
JP2015175283A (en) * 2014-03-14 2015-10-05 トヨタ自動車株式会社 Control device for internal combustion engine
JP2016053312A (en) * 2014-09-03 2016-04-14 日産自動車株式会社 Internal combustion engine igniter and internal combustion engine ignition method
JP2016217190A (en) * 2015-05-15 2016-12-22 株式会社日本自動車部品総合研究所 Ignition device
JP2017002791A (en) * 2015-06-09 2017-01-05 株式会社日本自動車部品総合研究所 Ignition control device
JP2017190677A (en) * 2016-04-11 2017-10-19 株式会社Ｓｏｋｅｎ Control device of internal combustion engine
WO2019181293A1 (en) * 2018-03-20 2019-09-26 日立オートモティブシステムズ株式会社 Internal combustion engine control device
WO2020121375A1 (en) * 2018-12-10 2020-06-18 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
WO2020235219A1 (en) * 2019-05-23 2020-11-26 日立オートモティブシステムズ株式会社 Control device for internal combustion engine
JP2021092226A (en) * 2021-03-18 2021-06-17 株式会社Ｓｏｋｅｎ Ignition control device of internal combustion engine

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