WO2022153611A1 - Internal combustion engine control device - Google Patents

Internal combustion engine control device Download PDF

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Publication number
WO2022153611A1
WO2022153611A1 PCT/JP2021/035058 JP2021035058W WO2022153611A1 WO 2022153611 A1 WO2022153611 A1 WO 2022153611A1 JP 2021035058 W JP2021035058 W JP 2021035058W WO 2022153611 A1 WO2022153611 A1 WO 2022153611A1
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WIPO (PCT)
Prior art keywords
jet
internal combustion
combustion engine
ignition
control device
Prior art date
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PCT/JP2021/035058
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French (fr)
Japanese (ja)
Inventor
直樹 米谷
英一郎 大畠
敦史 島田
健太 光藤
義寛 助川
賢吾 熊野
Original Assignee
日立Astemo株式会社
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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 CN202180077865.6A priority Critical patent/CN116472399A/en
Publication of WO2022153611A1 publication Critical patent/WO2022153611A1/en

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    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
    • F02B—INTERNAL-COMBUSTION PISTON ENGINES; COMBUSTION ENGINES IN GENERAL
    • F02B19/00—Engines characterised by precombustion chambers
    • F02B19/12—Engines characterised by precombustion chambers with positive ignition
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
    • F02D—CONTROLLING COMBUSTION ENGINES
    • F02D45/00—Electrical control not provided for in groups F02D41/00 - F02D43/00
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02T—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO TRANSPORTATION
    • Y02T10/00—Road transport of goods or passengers
    • Y02T10/10—Internal combustion engine [ICE] based vehicles
    • Y02T10/40—Engine management systems

Definitions

  • the present invention relates to an internal combustion engine control device.
  • a gasoline engine in which a mixture of fuel and air is formed in a combustion chamber and burned by ignition or self-ignition.
  • a sub-chamber type flame jet ignition hereinafter, sub-chamber combustion
  • an air-fuel mixture is ignited in a sub-combustion chamber, which is a minute space of several cc, and a flame jet is injected into the main combustion chamber.
  • sub-chamber combustion a sub-chamber type flame jet ignition
  • a spark plug In a general gasoline engine, a spark plug is fixed to the upper part of the main combustion chamber so that the tip is exposed to the combustion chamber. Then, at the start of combustion, sparks due to electric discharge are generated from the spark plug to directly ignite the air-fuel mixture in the main combustion chamber.
  • a sub-chamber is provided in the upper part of the combustion chamber, and the spark plug is fixed so as to be exposed in the sub-chamber.
  • This sub-chamber is provided with a sub-chamber injection hole that communicates with the main combustion chamber.
  • the air-fuel mixture is first ignited in the sub-chamber.
  • a jet containing a high temperature and unburned air-fuel mixture is ejected from the sub-chamber injection hole toward the main combustion chamber side, and the air-fuel mixture on the main combustion chamber side is ignited by this jet.
  • ignition occurs at multiple points at the same time, and combustion progresses more rapidly than when the sub chamber is not used, so combustion stability is improved.
  • the sub-chamber combustion makes it possible to carry out lean combustion, which burns an air-fuel mixture whose fuel is thinner than the theoretical air-fuel ratio, in a higher dilution state.
  • the reduction improves thermal efficiency.
  • the combustion gas can reach the abnormal combustion generation region before the abnormal combustion such as knocking occurs, and as a result, the knocking suppression effect can be obtained.
  • the optimum ignition timing can be taken even in a high load region, the exhaust loss is reduced, and the thermal efficiency is further improved as compared with the case where the sub chamber is not used.
  • Patent Document 1 includes a technology including a pressure sensor that detects the pressure in the sub-combustion chamber and an ignition control unit that controls ignition of the spark plug according to the operating state of the internal combustion engine and the detected pressure in the sub-combustion chamber. Is described.
  • Patent Document 1 has a problem that a pressure sensor for detecting the pressure in the sub-chamber is required and the system cost increases.
  • the higher the strength of the jet ejected from the sub chamber the more stable ignition of the air-fuel mixture becomes possible.
  • the jet strength is too high, the heat loss to the wall surface of the sub chamber and the wall surface of the main combustion chamber increases. As a result, fuel consumption may increase and the effect of reducing fuel consumption due to combustion in the sub-chamber may decrease. If the jet strength is further increased, the pressure fluctuation in the main combustion chamber due to the jet ejection may induce knocking. Therefore, it is required to accurately estimate the jet strength in order to adjust the jet strength to an appropriate range while balancing combustion stability and heat loss.
  • the purpose of this object is to provide an internal combustion engine control device that can estimate the jet strength without using a pressure sensor that detects the pressure in the sub chamber in consideration of the above problems.
  • the internal combustion engine control device includes a main combustion chamber facing the piston, a sub-combustion chamber, a spark plug, a crank shaft, a crank angle sensor, a cylinder, and a knock sensor. And controls an internal combustion engine equipped with.
  • the sub-combustion chamber communicates with the main combustion chamber.
  • the spark plug is mounted inside the sub-combustion chamber.
  • the crank shaft is connected to the piston.
  • the crank angle sensor detects the rotation angle of the crank shaft.
  • the cylinder forms the main combustion chamber.
  • the knock sensor detects the vibration of the cylinder.
  • the internal combustion engine control device includes an ignition time estimation unit, a crank angle information acquisition unit, a rotation fluctuation acquisition unit, and a jet intensity estimation unit.
  • the ignition time estimation unit estimates the ignition time of the air-fuel mixture in the main combustion chamber by the jet injected from the sub-combustion chamber based on the knock sensor signal detected by the knock sensor.
  • the crank angle information acquisition unit acquires the crank angle information detected by the crank angle sensor.
  • the rotation fluctuation acquisition unit calculates the amount of rotation speed change that occurs after the ignition time based on the crank angle information.
  • the jet intensity estimation unit estimates the jet intensity by calculating the rotation speed change rate that occurs after the ignition time based on the rotation speed change amount calculated by the rotation fluctuation acquisition unit and the ignition time estimated by the ignition time estimation unit. ..
  • the jet strength can be accurately estimated without using a pressure sensor that detects the pressure in the sub chamber.
  • FIG. 1 It is a schematic block diagram which shows the system structure of the internal combustion engine equipped with the internal combustion engine control device which concerns on the 1st Embodiment example. It is a schematic block diagram which shows the structure around the cylinder of the internal combustion engine which mounted the internal combustion engine control device which concerns on the 1st Embodiment example. It is a block diagram which shows the structure of the internal combustion engine control device which concerns on the 1st Embodiment example. It is a block diagram which shows the structure of the jet intensity estimation processing in the internal combustion engine control device which concerns on the 1st Embodiment example. It is a figure explaining the combustion consumption amount and the heat loss amount by the difference of a jet intensity, and FIG.
  • FIG. 5A is a figure which shows the difference between the pressure of a sub chamber and the pressure of a main combustion chamber by a difference of a jet intensity.
  • FIG. 5B is a diagram showing the relationship between the difference in jet intensity and the combustion consumption rate
  • FIG. 5C is a diagram showing the relationship between the difference in jet intensity and the amount of heat loss.
  • the changes in pressure, pressure difference, rotation speed and vibration (acceleration) of the auxiliary chamber and the main combustion chamber per one combustion cycle are shown.
  • FIG. 6 (a) shows the pressure in the auxiliary chamber
  • FIG. 6 (b) shows the main combustion.
  • the pressure in the chamber, FIG. 6 (c) is the pressure difference,
  • FIG. 6 (d) is the rotation speed, and
  • FIG. 6 (e) is the vibration (acceleration).
  • FIG. 8A shows a waveform showing an output value of the knock sensor
  • FIG. 8B shows a knock sensor signal.
  • FIG. 8C is a diagram showing an absolute value of the filter output value. It is a graph which shows the accuracy of the estimation result of the jet intensity estimated by the internal combustion engine control device which concerns on the 1st Embodiment example of the estimation result of the conventional jet intensity.
  • FIG. 11A is a graph showing an example of the increase / decrease process
  • FIG. 11B is a graph showing another example of the increase / decrease process, showing the jet intensity increase / decrease process in the internal combustion engine control device according to the first embodiment
  • FIG. 12A is a graph showing an example of the increase / decrease process
  • FIG. 12B is a graph showing another example of the increase / decrease process, showing the jet intensity increase / decrease process in the internal combustion engine control device according to the first embodiment.
  • FIG. 1 is a schematic configuration diagram showing a system configuration of the internal combustion engine of this example.
  • FIG. 2 is a schematic configuration diagram showing a configuration around a cylinder of an internal combustion engine.
  • the internal combustion engine 100 shown in FIG. 1 is an in-cylinder injection type internal combustion engine (direct injection engine) that directly injects fuel made of gasoline into the cylinder.
  • the internal combustion engine 100 is a four-cycle engine that repeats four strokes of an intake stroke, a compression stroke, a combustion (expansion) stroke, and an exhaust stroke. Further, the internal combustion engine 100 is, for example, a multi-cylinder engine including four cylinders (cylinders). The number of cylinders of the internal combustion engine 100 is not limited to four, and may have six or eight or more cylinders.
  • the internal combustion engine 100 includes an air flow sensor 1, an electronically controlled throttle valve 2, an intake pressure sensor 3, a supercharger 4, an intercooler 7, and a cylinder 14.
  • the air flow sensor 1, the electronically controlled throttle valve 2, the intake pressure sensor 3, the compressor 4a of the supercharger 4, and the intercooler 7 are arranged at positions up to the cylinder 14 in the intake pipe 6.
  • the air flow sensor 1 measures the intake air amount and the intake air temperature.
  • the electronically controlled throttle valve 2 is driven so as to be openable and closable by a drive motor (not shown). Then, the opening degree of the electronically controlled throttle valve 2 is adjusted based on the accelerator operation of the driver. As a result, the amount of air taken into the intercooler 7 and the cylinder 14 is adjusted.
  • the compressor 4a is a supercharger that supercharges the intake air.
  • a rotational force is transmitted to the compressor 4a by a turbine 4b, which will be described later.
  • the intercooler 7 is arranged on the upstream side of the cylinder 14, and is arranged on the downstream side of the electronically controlled throttle valve 2 and the airflow sensor 1. Then, the intercooler 7 cools the intake air.
  • the internal combustion engine 100 includes an injector 13 for injecting fuel into the cylinder of the cylinder 14, an ignition device 16 including an ignition coil 16 for supplying ignition energy, and an ignition plug 17, and a sub.
  • a chamber 8 and a knock sensor 47 are provided for each cylinder 14.
  • the ignition coil 16 generates a high voltage under the control of the internal combustion engine control device 20 and applies it to the spark plug 17. As a result, sparks are generated in the spark plug 17.
  • the spark plug 17 is arranged in the sub chamber 8 provided in the cylinder 14.
  • the hollow sub chamber 8 is inserted into the cylinder of the cylinder 14. Therefore, the internal combustion engine 100 of this example is divided into a main combustion chamber 14a formed in the cylinder of the cylinder 14 and a sub-combustion chamber formed by the sub chamber 8.
  • the sub chamber 8 is fixed to the cylinder head with its tip exposed in the main combustion chamber 14a.
  • a sub-chamber injection hole 8a communicating with the main combustion chamber 14a is formed at the tip of the sub-chamber 8.
  • the sub-combustion chamber and the main combustion chamber 14a formed by the sub-chamber 8 are. It communicates with the auxiliary chamber injection hole 8a. Then, the air-fuel mixture is taken into the sub-chamber 8 from the main combustion chamber 14a via the sub-chamber injection hole 8a.
  • the air-fuel mixture in the sub-combustion chamber is burned by the spark generated in the spark plug 17.
  • the flame generated in the sub chamber 8 passes through the sub chamber injection hole 8a and is ejected as a plurality of flame jets into the main combustion chamber 14a, ignites the air-fuel mixture in the main combustion chamber 14a, and the main combustion is performed.
  • the flame jet injected from the sub-chamber injection hole 8a is simply referred to as a jet.
  • ignition occurs at multiple points at the same time, combustion proceeds more rapidly than in the case where the sub chamber 8 is not used, and the stability of combustion is improved.
  • the flame jet injected from the sub-chamber injection hole 8a is simply referred to as a jet.
  • a voltage sensor (not shown) is attached to the ignition coil 16.
  • the voltage sensor measures the primary side voltage or the secondary side voltage of the ignition coil 16. Then, the voltage information measured by the voltage sensor is sent to the internal combustion engine control device 20 which is an ECU (Engine Control Unit).
  • ECU Engine Control Unit
  • the cylinder head of the cylinder 14 is provided with a variable valve 5. As shown in FIG. 2, it has an intake side timing mechanism 5a, an exhaust side timing mechanism 5b, an intake valve 31, and an exhaust valve 32.
  • the intake valve 31 is arranged at the intake port to which the intake pipe 6 of the cylinder 14 is connected, and the exhaust valve 32 is arranged at the exhaust port of the cylinder 14 to which the exhaust pipe 15 described later is connected.
  • the variable valve 5 adjusts the valve opening and closing magnetism of the intake valve 31 and the exhaust valve 32 by the intake side timing mechanism 5a and the exhaust side timing mechanism 5b. As a result, the air-fuel mixture flowing into the cylinder of the cylinder 14 or the exhaust gas discharged from the cylinder is adjusted. By adjusting the variable valve 5, the intake amount and the internal EGR amount of all the cylinders 14 are adjusted.
  • the piston 18 is slidably arranged in the cylinder of the cylinder 14.
  • the piston 18 compresses the mixture of fuel and gas that has flowed into the cylinder of the cylinder 14. Then, the piston 18 reciprocates in the cylinder of the cylinder 14 due to the combustion pressure generated in the cylinder.
  • a crank shaft 48 is connected to the piston 18 via a connecting rod.
  • crank angle sensor 49 is provided to detect the angle of the crank shaft 48.
  • the crank angle sensor 49 detects teeth provided at predetermined angular intervals (for example, 6 deg) in the circumferential direction of the crank shaft 48.
  • the knock sensor 47 is attached to the side surface portion of the cylinder 14 or the cylinder head.
  • the knock sensor 47 is an acceleration sensor that detects the vibration of the cylinder 14.
  • the position where the knock sensor 47 is provided is not limited to the side surface portion of the cylinder 14, and may be any position where vibration of the cylinder 14 can be detected, such as the upper part of the cylinder head.
  • the vibration signal (acceleration information) of the cylinder 14 detected by the knock sensor 47 is output to the internal combustion engine control unit (ECU) 20, which will be described later. Then, when the ECU 20 determines that the vibration signal from the knock sensor 47 exceeds the preset knock threshold value, the ECU 20 detects the occurrence of knocking.
  • ECU internal combustion engine control unit
  • the injector 13 is controlled by an internal combustion engine control unit (ECU) 20, which will be described later, to inject fuel into the cylinder of the cylinder 14.
  • ECU internal combustion engine control unit
  • a high-pressure fuel pump (not shown) is connected to the injector 13.
  • the fuel whose pressure has been increased by the high-pressure fuel pump is supplied to the injector 13.
  • a fuel pressure sensor for measuring the fuel injection pressure is provided in the fuel pipe connecting the injector 13 and the high-pressure fuel pump.
  • the port injection injector 13B may be attached to the intake pipe 6, and fuel may be injected from the port injection injector 13B into the intake port.
  • the exhaust pipe 15 is provided with a turbine 4b, an electronically controlled wastegate valve 11, a three-way catalyst 10, and an air-fuel ratio sensor 9.
  • the turbine 4b is rotated by the exhaust gas passing through the exhaust pipe 15 and transmits the rotational force to the compressor 4a.
  • the electronically controlled wastegate valve 11 adjusts the exhaust flow path flowing through the turbine 4b.
  • the three-way catalyst 10 purifies harmful substances contained in the exhaust gas by an oxidation / reduction reaction. Further, the air-fuel ratio sensor 9 is arranged on the upstream side of the three-way catalyst 10. Then, the air-fuel ratio sensor 9 detects the air-fuel ratio of the exhaust gas passing through the exhaust pipe 15.
  • the internal combustion engine 100 includes an EGR flow path tube 40 that recirculates exhaust gas (EGR gas) from the downstream side of the three-way catalyst 10 to the upstream side of the compressor 4a and the downstream side of the air flow sensor 1. ..
  • the EGR flow path tube 40 is provided with an EGR cooler 42, an EGR valve 41, and a differential pressure sensor 43.
  • the EGR cooler 42 cools the EGR gas.
  • the EGR valve 41 controls the EGR flow rate that regulates the flow rate of the EGR gas passing through the EGR flow path pipe 40.
  • a differential pressure sensor 43 that detects the differential pressure before and after the EGR valve 41 is attached in the vicinity of the EGR valve 41.
  • the differential pressure before and after the EGR valve 41 is the difference between the pressure on the upstream side and the pressure on the downstream side of the EGR valve 41 in the EGR flow path pipe 40.
  • the EGR temperature sensor 44 is arranged downstream of the EGR valve 41. The EGR temperature sensor 44 detects the temperature of the EGR gas flowing through the EGR flow path tube 40.
  • a part of the exhaust gas purified by the three-way catalyst 10 flows into the EGR flow path pipe 40 without being discharged to the outside, and is used as EGR gas.
  • the EGR gas After passing through the EGR cooler 42 and the EGR valve 41, the EGR gas joins the fresh air taken in upstream of the compressor 4a. After that, the mixed gas of EGR gas and fresh air flows into the cylinder 14 after passing through the intercooler 7 and the electronically controlled throttle valve 2.
  • the signals detected by each sensor such as the air flow sensor 1, the intake pressure sensor 3, and the knock sensor 47 are sent to the internal combustion engine control device 20 which is an ECU (Engine Control Unit). Further, the amount of depression of the accelerator pedal, that is, the signal detected by the accelerator opening sensor 12 that detects the accelerator opening is also sent to the internal combustion engine control device 20.
  • the internal combustion engine control device 20 calculates the required torque based on the main signal of the accelerator opening sensor 12. That is, the accelerator opening degree sensor 12 is used as a required torque detection sensor for detecting the required torque for the internal combustion engine 100. Further, the internal combustion engine control device 20 calculates the rotation speed of the internal combustion engine 100 based on the output signal of a crank angle sensor (not shown). Then, the internal combustion engine control device 20 optimally optimizes the main operating amounts of the internal combustion engine 100 such as air flow rate, fuel injection amount, ignition timing, and fuel pressure, based on the operating state of the internal combustion engine 100 obtained from the outputs of various sensors. Calculate.
  • the fuel injection amount calculated by the internal combustion engine control device 20 is converted into a valve opening pulse signal and output to the injector 13. Further, the ignition timing calculated by the internal combustion engine control device 20 is output to the spark plug 17 as an ignition signal. Further, the throttle opening calculated by the internal combustion engine control device 20 is output to the electronically controlled throttle valve 2 as a throttle drive signal. Further, the EGR valve opening degree calculated by the internal combustion engine control device 20 is output to the EGR valve 41 as an EGR valve opening degree driving signal.
  • FIG. 3 is a block diagram showing the configuration of the internal combustion engine control device 20.
  • the internal combustion engine control device 20 which is an ECU (Engine Control Unit) includes an input circuit 21, an input / output port 22, a RAM (RandomAccessMemory) 23c, and a ROM (ReadOnlyMemory) 23b. , CPU (Central Processing Unit) 23a. Further, the internal combustion engine control device 20 has an ignition control unit 24.
  • ECU Engine Control Unit
  • RAM RandomAccessMemory
  • ROM ReadOnlyMemory
  • CPU Central Processing Unit
  • the suction flow rate from the air flow sensor 1, the intake pressure from the intake pressure sensor 3, and the coil primary voltage or secondary voltage from the voltage sensor are input to the input circuit 21. Further, information measured by various sensors such as accelerator opening degree, rotation speed, humidity, air amount, crank angle, ignition device information, and knock sensor information is input to the input circuit 21.
  • the input circuit 21 performs signal processing such as noise reduction on the input signal and sends it to the input / output port 22.
  • the value input to the input port of the input / output port 22 is stored in the RAM 23c.
  • the ROM 23b stores a control program that describes the contents of various arithmetic processes executed by the CPU 23a, a MAP, a data table, and the like used for each process.
  • the RAM 23c is provided with a storage area for storing the value input to the input port of the input / output port 22 and the value representing the operation amount of each actuator calculated according to the control program. Further, a value representing the operation amount of each actuator stored in the RAM 23c is sent to the output port of the input / output port 22.
  • the ignition signal set in the output port of the input / output port 22 is sent to the ignition coil 16 via the ignition control unit 24.
  • the ignition control unit 24 controls the energization timing and energization time of the ignition coil 16. Further, the ignition control unit 24 controls the discharge energy at the spark plug 17.
  • the present invention is not limited to this.
  • a part of the ignition control unit 24 or all of the ignition control unit 24 may be mounted on a control device different from the internal combustion engine control device 20.
  • the internal combustion engine control device 20 estimates the intensity of the jet injected from the sub-chamber injection hole 8a of the sub-chamber 8 based on the output signals from various sensors, and controls the ignition timing at the spark plug 17.
  • FIG. 4 is a block diagram showing a configuration of jet intensity estimation processing in the internal combustion engine control device 20.
  • the internal combustion engine control device 20 includes a knock sensor signal acquisition unit 101, a bandwidth / threshold acquisition unit 102, a crank angle information acquisition unit 103, a rotation fluctuation acquisition unit 104, and an ignition time estimation unit. It has 105 and a crank shaft acceleration start time estimation unit 106. Further, the internal combustion engine control device 20 includes a jet intensity estimation unit 107, a jet intensity comparison unit 108, an ignition timing output unit 109, and a jet intensity upper limit value / lower limit value calculation unit 110.
  • the knock sensor signal acquisition unit 101 is connected to the knock sensor 47 and acquires the knock sensor signal from the knock sensor 47 and the vibration information of the cylinder 14, that is, the acceleration information.
  • the knock sensor signal acquisition unit 101 is connected to the ignition time estimation unit 105, and outputs the acquired knock sensor signal to the ignition time estimation unit 105.
  • Bandwidth / threshold value acquisition unit 102 is input with engine speed information, engine shape information, and the like.
  • the shape information of the engine is the number of cylinders 14 mounted on the engine, that is, the number of cylinders.
  • the bandwidth / threshold acquisition unit 102 sets the bandwidth set value when filtering the knock sensor signal in the ignition time estimation unit 105, and the threshold used for the ignition time estimation process is used for engine speed information. And the shape information of the engine.
  • the bandwidth / threshold value acquisition unit 102 outputs the acquired bandwidth and threshold value to the ignition time estimation unit 105.
  • the bandwidth / threshold value acquisition unit 102 sets the low frequency side of the bandwidth so that the natural frequency of the engine and the mechanical vibration due to rotation are not included. That is, the higher the engine speed, the higher the natural frequency, so the lower limit of the bandwidth is set larger.
  • the natural frequency varies depending on the number of cylinders of the engine, that is, a 4-cylinder engine or a 3-cylinder engine. Therefore, the bandwidth / threshold value acquisition unit 102 changes the lower limit of the bandwidth based on the number of cylinders of the engine to be controlled so that the natural frequency is not included in the set value of the bandwidth.
  • the bandwidth / threshold value acquisition unit 102 is set so that the threshold value becomes smaller as the engine speed and the engine load become smaller.
  • the ignition time estimation unit 105 filters the knock sensor signal output from the knock sensor signal acquisition unit 101 based on the bandwidth output from the bandwidth / threshold value acquisition unit 102, and extracts the combustion component. .. Further, the ignition time estimation unit 105 estimates the ignition time by the jet (jet start time t jet ) based on the extracted combustion component and the threshold value output from the bandwidth / threshold value acquisition unit 102. Then, the ignition time estimation unit 105 outputs the estimated ignition time to the crank shaft acceleration start time estimation unit 106.
  • the crank shaft acceleration start time estimation unit 106 indicating the ignition time correction unit accelerates the crank shaft 48 based on the ignition time output from the ignition time estimation unit 105 and the time delay caused by the piston mechanism stored in advance. Is estimated, that is, the crank shaft acceleration start timing t acc is estimated. That is, the rank axis acceleration start time estimation unit 106 corrects the ignition time based on the time delay caused by the piston mechanism. Then, the crank shaft acceleration start time estimation unit 106 outputs the estimated crank shaft acceleration start timing to the jet intensity estimation unit 107.
  • the crank angle information acquisition unit 103 is connected to the crank angle sensor 49, and acquires crank angle information from the crank angle sensor 49. Then, the crank angle information acquisition unit 103 outputs the acquired crank angle information to the rotation fluctuation acquisition unit 104.
  • the rotation fluctuation acquisition unit 104 acquires (calculates) the amount of rotation change that occurs after the ignition time based on the crank angle information.
  • the rotation fluctuation acquisition unit 104 acquires the amount of change in the rotation speed for each distance between the teeth provided on the crank shaft 48. Further, the rotation fluctuation acquisition unit 104 outputs the acquired rotation speed change amount to the jet intensity estimation unit 107.
  • the jet strength estimation unit 107 estimates the jet strength based on the crank shaft acceleration start timing and the fluctuation amount of the rotation speed. Then, the jet intensity estimation unit 107 outputs the estimated jet intensity to the jet intensity comparison unit 108.
  • the jet intensity comparison unit 108 compares the jet intensity estimated by the jet intensity estimation unit 107 with the upper limit value and the lower limit value calculated by the jet intensity upper limit value / lower limit value calculation unit 110. Then, the jet intensity comparison unit 108 outputs the comparison result to the ignition timing output unit 109.
  • the ignition timing output unit 109 controls the ignition timing based on the result of comparison by the jet intensity comparison unit 108.
  • FIG. 5A shows the difference (pressure difference) between the pressure in the sub chamber 8 and the pressure in the main combustion chamber 14a due to the difference in jet strength.
  • the vertical axis shows the pressure difference [MPa] and the horizontal axis shows the crank angle.
  • FIG. 5B is a diagram showing the relationship between the difference in jet intensity and the combustion consumption rate
  • FIG. 5C is a diagram showing the relationship between the difference in jet intensity and the amount of heat loss to the wall surface of the main combustion chamber 14a.
  • the vertical axis in FIG. 5B shows the heat consumption rate ISFC [g / kWh]
  • the vertical axis in FIG. 5C shows the heat loss amount [W].
  • the horizontal axis in FIGS. 5B and 5C indicates the jet intensity.
  • the pressure difference becomes the maximum value when the sub chamber injection hole 8a ejects from the sub chamber 8 to the main combustion chamber 14a. Then, the maximum value of this pressure difference is defined as the jet intensity. Further, the higher the jet intensity ejected from the sub chamber 8, the more stable the ignition of the air-fuel mixture is. However, when the jet strength is high, as shown in FIG. 5C, the heat loss to the wall surface of the sub chamber 8 and the main combustion chamber 14a increases. As a result, as shown in FIG. 5B, the fuel consumption rate (fuel consumption) may increase, and the fuel consumption reduction effect of the sub-combustion chamber may decrease.
  • FIG. 6 shows the pressure in the sub chamber 8
  • FIG. 6 (b) shows the pressure in the main combustion chamber 14a
  • FIG. 6 (c) shows the pressure difference
  • FIG. 6 (d) shows the number of revolutions
  • FIG. 6 (e) shows the acceleration. That is, the output value of the knock sensor is shown.
  • the data shown in FIGS. 6 (a) and 6 (b) directly plot the measured waveforms.
  • the data shown in FIG. 6 (c) is data obtained by filtering the data obtained by taking the difference between the data shown in FIGS. 6 (a) and 6 (b) and performing noise reduction processing. ..
  • the pressure in the sub-chamber 8 reaches its first peak at top dead center. After that, the pressure rises again due to combustion and reaches the second peak. Then, as shown in FIG. 6B, the pressure behavior of the main combustion chamber 14a is almost the same as the pressure behavior of the sub chamber 8. However, as shown in FIGS. 6 (a) and 6 (b), a slight phase difference occurs between the two. Therefore, immediately after the pressure in the sub chamber 8 starts to rise due to combustion, the pressure difference between the sub chamber 8 and the main combustion chamber 14a reaches a peak as shown in FIG. 6 (c). The moment when the peak of this pressure difference is reached is the timing at which the jet is injected from the sub chamber 8 into the main combustion chamber 14a, and is regarded as the start time of the jet.
  • FIG. 6D is a diagram in which the engine speed is calculated based on the signal detected by the crank angle sensor 49.
  • the crank angle sensor 49 having a crank angle detection interval of 6 deg is used. That is, the crank angle sensor 49 detects the teeth provided on the crank shaft 48 at every 6 deg crank angle. Then, the crank angle information acquisition unit 103 detects a time difference from the time when one previous tooth is detected, obtains the time required for the crank shaft 48 to advance 6 deg based on the time difference, and obtains the time required for the crank shaft 48 to advance by 6 deg from this time. The number of rotations is calculated.
  • the engine speed constantly fluctuates by several tens of rpm in one combustion cycle.
  • a negative torque is generated, so that the rotation speed decreases.
  • the piston 18 is pressed by the combustion pressure, so that the top dead center is 360 deg. 450 deg. From after ATDC to the middle of the expansion process. The number of revolutions increases toward ATDC.
  • the frequency of the vibration waveform is changed at the start time of the jet, but there are many scenes where vibration is generated other than the combustion time. It is considered that this is mainly the load fluctuation on the engine side and the mechanical vibration when opening and closing the valve. Therefore, these effects can be eliminated by performing appropriate filtering.
  • the relationship between the engine speed and the pressure in the main combustion chamber 14a will be described.
  • the torque generated during combustion that is, the combustion torque ⁇ comb
  • the torque generated during combustion is the following number 1 from the friction torque ⁇ fric , the inertia torque ⁇ inner , the load torque ⁇ load , and the inertia J of the engine rotation system. It is represented by.
  • the combustion torque ⁇ comb in order to obtain the combustion torque ⁇ comb , it is necessary to calculate the differential value d ⁇ of the angular velocity ⁇ .
  • the angular velocity ⁇ measured by the crank angle sensor 49 contains various noises. Therefore, when normal differentiation is performed, this noise is emphasized and an accurate torque waveform cannot be reproduced. Therefore, in order to avoid the emphasis of noise due to differentiation, the combustion torque ⁇ comb may be estimated using the result of cutting the high frequency component included in the angular velocity ⁇ .
  • the differential value d ⁇ of the angular velocity ⁇ is referred to as a rotation speed change rate.
  • the estimated combustion ⁇ comb includes an offset due to the friction torque ⁇ fric and the load torque ⁇ load . Therefore, this offset amount is estimated and corrected by pre-adaptation.
  • the geometric features of the connecting rod of the 4-cylinder engine can be used to cancel this offset and obtain the corrected estimated torque ⁇ compression .
  • the relationship between the estimated torque ⁇ compression after this correction and the engine speed, that is, the angular velocity ⁇ is the following equation 2.
  • the pressure in the main combustion chamber 14a that is, the in-cylinder pressure Pcomb is calculated from the obtained estimated torque ⁇ compression .
  • the relationship between the estimated torque ⁇ compression and the in-cylinder pressure P comb is determined by the piston mechanism, and is therefore represented by the following equation 3.
  • a coil indicates the cross-sectional area of the main combustion chamber 14a
  • R indicates the length of the crank arm
  • ⁇ indicates the angle between the crank arm and the central axis.
  • FIG. 7 is an image diagram showing a method of estimating the rotation speed change rate d ⁇ .
  • the horizontal axis represents the time and the vertical axis represents the engine speed (angular velocity ⁇ ).
  • the black circles shown in FIG. 7 indicate the detection signal of the crank angle sensor 49 (crank angle sensor signal).
  • the clan angle sensor signal is a discrete value whose output value is updated for each tooth spacing.
  • the engine speed between the teeth is calculated by linearly interpolating the engine speed in the front and rear sections thereof, so that the line graph is as shown in the solid lines A1 and A2 shown in FIG.
  • the solid line A1 shows the estimation method of this example, and the solid line A2 shows the conventional estimation method.
  • the dotted line shown in FIG. 7 shows the actual rotation speed behavior.
  • the rotation speed change amount ⁇ in the section (t x + 1 ⁇ t x ) where acceleration is generated by the jet after the ignition timing is calculated by the rotation speed fluctuation acquisition unit 104 based on the following equation 5.
  • the rotation speed change rate d ⁇ is calculated using only the signal of the crank angle sensor 49. That is, the rotation speed change rate d ⁇ is calculated by dividing the rotation speed change amount ⁇ by the length of the section (t x + 1 ⁇ t x ), as shown in Equation 6 below.
  • the rotation speed change rate d ⁇ calculated by Equation 6 represents the change in the average rotation speed in the section of the crank angle of 6 deg, and corresponds to the slope of the solid line A2 shown in FIG.
  • the influence is smoothed and sufficient estimation accuracy cannot be obtained.
  • the rotation speed change rate d ⁇ is calculated using the signal of the knock sensor 47, which is an acceleration sensor, and the crank angle signal of the crank angle sensor 49.
  • the knock sensor signal acquisition unit 101 acquires the signal of the knock sensor 47 shown in FIG. 6 (e).
  • the ignition time estimation unit 105 processes the knock sensor signal acquired by the knock sensor signal acquisition unit 101.
  • FIG. 8A is a waveform showing an output value (knock sensor signal) of the knock sensor 47
  • FIG. 8B is a waveform showing a filter output value obtained by filtering the knock sensor signal
  • FIG. 8C is a diagram showing an absolute value of the filter output value.
  • the ignition time estimation unit 105 filters the knock sensor signal shown in FIG. 8A to obtain the filter output value shown in FIG. 8B. That is, the ignition time estimation unit 105 extracts the vibration component caused by combustion by filtering the knock sensor signal.
  • the ignition time estimation unit 105 performs a bandpass filter on the knock sensor signal using the bandwidth output from the bandwidth / threshold value acquisition unit 102 as a filter process.
  • the band region of the bandpass filter was set to 1.0 kHz to 2.0 kHz.
  • the lower limit of the band region is set to 1.0 kHz.
  • the upper limit of the band region is set to 2.0 kHz.
  • the bandwidth that is, the bandwidth is not limited to the above-mentioned 1.0 kHz to 2.0 kHz, and as described above, the bandwidth / threshold value acquisition unit 102 provides engine speed information and engine shape information. It is set appropriately based on the above.
  • the ignition time estimation unit 105 converts the filter output value shown in FIG. 8B into an absolute value, and obtains the waveform shown in FIG. 8C, that is, the amplitude of vibration. Then, the ignition time estimation unit 105 determines the timing at which the vibration amplitude exceeds the threshold value output from the bandwidth / threshold value acquisition unit 102 as the jet start timing, and obtains the jet start time t jet .
  • the threshold value is appropriately set by the bandwidth / threshold value acquisition unit 102 based on the engine speed.
  • the crank shaft acceleration start time estimation unit 106 estimates the crank shaft acceleration start timing t acc based on the jet start time t jet . As shown in Equation 4 above, there is a response delay due to the inertial mass of the piston mechanism and the crank shaft 48 from the increase in pressure in the main combustion chamber 14a to the increase in rotation speed. Therefore, the crank shaft acceleration start time estimation unit 106 is provided with a plurality of profiles of the in-cylinder pressure Pcomb ( ⁇ ) of the main combustion chamber 14a at which the pressure increase start timing by the jet is changed.
  • the response of the rotation speed change rate d ⁇ ( ⁇ ) to those profiles is calculated, and the time delay ⁇ t ( ⁇ ) from the increase in pressure in the main combustion chamber 14a to the occurrence of the increase in rotation speed is used as a table for the crank shaft. It is stored in the acceleration start time estimation unit 106.
  • crank shaft acceleration start timing t acc is calculated by the following equation 7.
  • crank shaft acceleration start time estimation unit 106 corrects the response delay caused by the piston mechanism, so that the actual acceleration start timing of the crank shaft 48 is accurate from the ignition time by the jet based on the knock sensor signal. It can be detected well.
  • the jet intensity estimation unit 107 calculates the rotation speed change rate d ⁇ using the rotation speed detected by the crank angle sensor 49, starting from the acceleration start timing of the crank shaft 48. That is, the jet intensity estimation unit 107 uses the rotation speed change amount ⁇ calculated in the above-mentioned equation 5 and the crank shaft acceleration start timing tac calculated in the equation 7, and the rotation speed change rate based on the equation 8. Calculate ⁇ .
  • ⁇ calculated by Equation 8 corresponds to the slope of the solid line A1 shown in FIG.
  • the calculation start point of the rotation speed change rate ⁇ is the crank shaft estimated by the knock sensor 47 from the detection time tx of the teeth of the crank angle sensor 49. It can be seen that the acceleration start timing is changed to tacc .
  • the solid line A1 obtained by the estimation method of this example can be closer to the actual rotation speed behavior shown by the dotted line than the solid line A2 obtained by the conventional estimation method.
  • the rotation speed change rate ⁇ is calculated with the calculation start point always set to the time tx regardless of the ignition timing by the jet. As a result, it is not possible to obtain a time resolution finer than the tooth spacing detected by the crank angle sensor 49.
  • the rotation speed change rate ⁇ is calculated with the crank shaft acceleration start timing tac as the calculation start point, the rotation speed change rate considering the jet start timing that fluctuates depending on the engine state. ⁇ can be calculated.
  • the jet intensity I_jet can be calculated indirectly based on the following equation tens using the rotation speed change rate ⁇ .
  • P pre is the pressure of the auxiliary combustion chamber.
  • the jet intensity I_jet can be estimated by estimating the rotation speed change rate ⁇ .
  • FIG. 9 is a graph showing the accuracy of the conventional jet intensity estimation result and the jet intensity estimation result of this example.
  • the horizontal axis of each graph shows the rotation speed change rate d ⁇ .
  • the vertical axis of each graph in FIG. 9 shows the pressure difference between the sub-combustion chamber and the main combustion chamber 14a, that is, the jet intensity.
  • the maximum value of the pressure difference is set to 0 deg. ATC, 3deg. ATC, 6deg. It is a plot of averaging 5 consecutive cycles with ATC.
  • the correlation coefficient between the rotation speed change rate d ⁇ and the jet intensity is 0.68.
  • the correlation coefficient between the rotation speed change rate d ⁇ and the jet strength is 0.87. It has become.
  • the accuracy of the jet strength estimation result of this example is higher than the accuracy of the conventional jet strength estimation result using only the crank angle sensor 49. That is, by using the information of the knock sensor 47 together, the time resolution of the rotation speed change rate d ⁇ can be improved, and the jet intensity can be estimated accurately without using the pressure sensor that detects the pressure in the sub chamber. can.
  • FIG. 10 is a flowchart showing a jet intensity correction control operation.
  • the internal combustion engine control device 20 determines whether or not the warming up of the engine is completed (step S11).
  • the jet strength is significantly reduced, and the combustion on the main combustion chamber 14a side may become unstable. Therefore, when it is determined in the process of step S11 that the warming up of the engine is not completed (NO determination in step S11), the internal combustion engine control device 20 ends the process without performing the jet strength correction process.
  • step S11 When it is determined in the process of step S11 that the warming up of the engine is completed (YES determination in step S11), the knock sensor signal acquisition unit 101 acquires knock sensor information from the knock sensor 47 (step S12). Then, the knock sensor signal acquisition unit 101 outputs the acquired knock sensor information (knock sensor signal) to the ignition time estimation unit 105.
  • the ignition time estimation unit 105 filters the knock sensor signal and extracts the combustion component (step S13).
  • the ignition time estimation unit 105 performs a bandpass filter on the knock sensor signal using the bandwidth output from the bandwidth / threshold value acquisition unit 102.
  • the filter output value shown in FIG. 8B can be obtained from the knock sensor signal shown in FIG. 8A.
  • the ignition time estimation unit 105 estimates the ignition time t jet by the jet based on the filter output value from which the combustion component is extracted (step S14). That is, the ignition time estimation unit 105 converts the filter output value into an absolute value as described above, and obtains the waveform shown in FIG. 8C, that is, the amplitude of vibration. Then, the ignition time estimation unit 105 estimates the timing when the threshold value output from the bandwidth / threshold value acquisition unit 102 is exceeded as the ignition time t jet by the jet. Further, the ignition time estimation unit 105 outputs the estimated ignition time t jet by the jet to the crank shaft acceleration start time estimation unit 106.
  • crank angle information acquisition unit 103 acquires crank angle information from the crank angle sensor 49 (step S15). Then, the crank angle information acquisition unit 103 outputs the acquired crank angle information to the rotation fluctuation acquisition unit 104. Further, the rotation speed change acquisition unit 104 calculates the rotation speed change amount ⁇ from the equation 5, and outputs the calculated rotation speed change amount ⁇ to the jet intensity estimation unit 107.
  • crank shaft acceleration start time estimation unit 106 estimates the crank shaft acceleration start timing (time) t acc based on the jet start time t jet and the equation 6 (step 16). Then, the crank shaft acceleration start time estimation unit 106 outputs the estimated crank shaft acceleration start time tac to the jet intensity estimation unit 107.
  • the jet intensity estimation unit 107 estimates the jet intensity I_jet from the rotation speed change rate d ⁇ that occurs after the acceleration start time tacc , based on the rotation speed change amount ⁇ and the crank shaft acceleration start time tacc. (Step S17). That is, the jet intensity estimation unit 107 calculates the rotation speed change rate d ⁇ based on the equation 8, and estimates the rotation speed change rate d ⁇ as the jet intensity I_jet. Then, the jet intensity estimation unit 107 outputs the estimated jet intensity I_jet to the jet intensity comparison unit 108.
  • the jet intensity comparison unit 108 determines whether or not the jet intensity I_jet is equal to or greater than the lower limit value Imin output from the jet intensity upper limit value / lower limit value calculation unit 110 (step S18). When it is determined in the process of step S18 that the jet intensity I_jet is smaller than the lower limit value Imin (NO determination in step S18), the internal combustion engine control device 20 performs the jet intensity increase process (step S19). When the jet intensity increasing process in step S19 is completed, the process returns to step S12 again.
  • step S18 when it is determined that the jet intensity I_jet is equal to or higher than the lower limit value Imin (YES determination in step S18), the process proceeds to the process of step S20.
  • the jet intensity comparison unit 108 determines whether or not the jet intensity I_jet is equal to or greater than the upper limit value Imax output from the jet intensity upper limit value / lower limit value calculation unit 110.
  • step S20 when it is determined that the jet intensity I_jet is larger than the upper limit value Imax (NO determination in step S20), the internal combustion engine control device 20 executes the jet intensity reduction process (step S21). When the jet intensity increasing process in step S21 is completed, the process returns to step S12 again.
  • step S20 When it is determined in the process of step S20 that the jet intensity I_jet is equal to or less than the upper limit value Imax (YES determination in step S20), the internal combustion engine control device 20 determines that the jet intensity I_jet is within an appropriate range. , End control.
  • FIG. 11A is a graph showing an example of jet intensity increase / decrease processing, in which the horizontal axis represents the jet intensity and the vertical axis represents the ignition timing.
  • the ignition timing output unit 109 corrects the ignition timing in the retard direction as the jet intensity I_jet becomes stronger. By retarding the ignition timing, the center of gravity of combustion is delayed, so that the combustion temperature in the sub chamber 8 is lowered. Thereby, the jet intensity I_jet can be reduced.
  • the ignition timing output unit 109 corrects the ignition timing in the advance angle direction. By advancing the ignition timing, the center of gravity of combustion is advanced and the combustion temperature in the sub chamber 8 rises. Thereby, the jet intensity I_jet can be increased.
  • FIG. 11B is a graph showing another example of jet intensity increase / decrease processing, in which the horizontal axis represents the jet intensity and the vertical axis represents the EGR rate target value [%].
  • the internal combustion engine control device 20 controls the EGR rate target value according to the jet intensity I_jet. That is, the stronger the jet intensity I_jet, the higher the EGR rate target value is corrected.
  • Increasing the EGR rate increases the dilution rate of the air-fuel mixture. As a result, the combustion temperature in the sub chamber 8 is lowered, and the jet intensity I_jet can be reduced.
  • the EGR rate target value is corrected to be low.
  • the dilution rate of the air-fuel mixture becomes low.
  • the combustion temperature in the sub chamber 8 rises, and the jet intensity I_jet can be increased.
  • FIG. 12A is a graph showing another example of jet intensity increase / decrease processing, in which the horizontal axis represents the jet intensity and the vertical axis represents the A / F target value.
  • the internal combustion engine control device 20 controls the A / F target value according to the jet intensity I_jet. That is, the stronger the jet intensity I_jet, the higher the A / F target value is corrected.
  • the dilution ratio of the air-fuel mixture is increased.
  • the combustion temperature in the sub chamber 8 is lowered, and the jet intensity I_jet can be reduced.
  • the jet intensity I_jet is weak, the A / F target value is corrected to be low.
  • the dilution ratio of the air-fuel mixture becomes low.
  • the combustion temperature in the sub chamber 8 rises, and the jet intensity I_jet can be increased.
  • FIG. 12B is a graph showing another example of the jet intensity increase / decrease process, in which the horizontal axis represents the jet intensity and the vertical axis represents the ignition energy [mJ].
  • the internal combustion engine control device 20 controls the ignition energy according to the jet intensity I_jet. That is, the stronger the jet intensity I_jet, the lower the ignition energy.
  • the ignition delay timing is increased, the combustion center of gravity is delayed, and the combustion temperature in the sub chamber 8 is lowered, as in the case of retarding the ignition timing.
  • the jet intensity I_jet can be reduced.
  • the jet intensity I_jet is weak, it is corrected so that the ignition energy becomes high.
  • the ignition delay timing is reduced, the combustion center of gravity is advanced, and the combustion temperature in the sub chamber 8 rises, as in the case of advancing the ignition timing.
  • the jet intensity I_jet can be increased.
  • the jet strength increase / decrease process is not limited to the above-mentioned example, and various other methods for increasing / decreasing the jet strength are applied.
  • FIG. 13 is a block diagram showing a configuration of jet strength estimation processing of the internal combustion engine control device according to the second embodiment.
  • FIG. 14 is a map showing the knock sensor amplitude reliability at the time of jet intensity estimation for each engine operating condition.
  • FIG. 15 is a diagram showing a method of estimating the jet strength by the second jet strength estimation unit of the internal combustion engine control device according to the second embodiment.
  • the parts common to the internal combustion engine control device 20 in the first embodiment are designated by the same reference numerals, and duplicate description will be omitted.
  • the internal combustion engine control device 20B includes a knock sensor signal acquisition unit 101, a bandwidth / threshold acquisition unit 102, a crank angle information acquisition unit 103, a rotation fluctuation acquisition unit 104, and an ignition time estimation unit. It has 105 and a crank shaft acceleration start time estimation unit 106. Further, the internal combustion engine control device 20B has a jet intensity comparison unit 108 and an ignition timing output unit 109. Since the configuration of these processing units is the same as that of the processing unit according to the first embodiment, the description thereof will be omitted.
  • the internal combustion engine control device 20B includes a first jet intensity estimation unit 207A, a second jet intensity estimation unit 207B, a jet intensity selection unit 201, a reliability rate ⁇ calculation unit 202, and a jet intensity upper limit value / lower limit value calculation. It has a unit 210. Since the configuration of the first jet intensity estimation unit 207A is the same as that of the jet intensity estimation unit 107 according to the first embodiment, the description thereof will be omitted. Further, the first jet intensity estimation unit 207A outputs the estimated first jet intensity to the jet intensity selection unit 201.
  • the second jet intensity estimation unit 207B is connected to the knock sensor 47 and acquires a knock sensor signal from the knock sensor 47.
  • the second jet intensity estimation unit 207B estimates the second jet intensity based on the knock sensor signal. The method of estimating the second jet intensity by the second jet intensity estimation unit 207B will be described later. Then, the second jet intensity estimation unit 207B outputs the estimated second jet intensity to the jet intensity selection unit 201.
  • the jet strength selection unit 201 is connected to the reliability rate ⁇ calculation unit 202, and the reliability rate ⁇ is output from the reliability rate ⁇ calculation unit 202. Then, the jet intensity selection unit 201 selects the jet intensity to be used as an index among the first jet intensity and the second jet intensity according to the reliability ⁇ . The jet intensity selection unit 201 outputs the selected jet intensity to the jet intensity comparison unit 108.
  • the jet intensity selection unit 201 determines that the reliability of the first jet intensity estimated by the first jet intensity estimation unit 207A is high, and selects the first jet intensity. Further, when the reliability rate ⁇ is equal to or higher than a predetermined value, the jet intensity selection unit 201 determines that the reliability of the second jet intensity estimated by the second jet intensity estimation unit 207B is high, and selects the second jet intensity.
  • the reliability rate ⁇ calculation unit 202 is connected to the accelerator opening sensor 12. Then, the throttle opening degree and the engine speed information are input from the accelerator opening degree sensor 12 to the reliability rate ⁇ calculation unit 202.
  • the reliability ⁇ calculation unit 202 has a map showing the knock sensor amplitude reliability ⁇ at the time of jet intensity estimation for each engine operating condition shown in FIG. In FIG. 14, the horizontal axis represents the engine speed [rpm], and the vertical axis represents the engine load IMEP [rpm].
  • the reliability ⁇ calculation unit 202 calculates the reliability ⁇ from the map shown in FIG. 14 based on the operating conditions of the engine, and outputs the calculation to the jet intensity selection unit 201.
  • the jet intensity upper limit value / lower limit value calculation unit 210 calculates the upper limit value and the lower limit value for the first jet intensity estimation unit 207A and the second jet intensity estimation unit 207B. That is, the jet intensity upper limit value / lower limit value calculation unit 210 calculates the upper limit value and the lower limit value according to the jet intensity selected by the jet intensity selection unit 201. Then, the jet intensity upper limit value / lower limit value calculation unit 210 outputs the calculated upper limit value and lower limit value to the jet intensity comparison unit 108.
  • the first jet intensity estimation unit 207A uses the knock sensor signal only for estimating the ignition time by the jet, and does not use the amplitude information of the knock sensor signal.
  • the amplitude information of the knock sensor signal also includes vibration at the time of ignition. Therefore, the knock sensor signal is used at low rotation where the mechanical vibration of the engine is relatively small, or at low load when the rotation fluctuation of the engine is small and the detection accuracy of the rotation fluctuation (rotation change amount ⁇ ) of the crank angle sensor 49 deteriorates.
  • the amplitude information of can be used to estimate the jet intensity.
  • the second jet intensity estimation unit 207B performs a filter process on the knock sensor signal in the same manner as the ignition time estimation unit 105, and sets the filter output value to absolute value. Convert to a value and get the amplitude of the vibration. Then, as shown in FIG. 15 (c), the second jet intensity estimation unit 207B sets the maximum amplitude value of the knock sensor signal in the range after the ignition timing and before the exhaust valve opening timing. -Estimated as kick sensor.
  • the internal combustion engine control device 20B having such a configuration can also obtain the same operation and effect as the internal combustion engine control device 20 according to the first embodiment described above.
  • the reliability of each sensor is set according to the operating state, and the sensor information used when estimating the jet intensity is determined. As a result, the performance of each sensor provided in the internal combustion engine 100 can be maximized, and the accuracy of estimating the jet strength can be improved.
  • the first jet intensity estimated by the first jet intensity estimation unit 207A and the second jet intensity estimation unit are used as the threshold value of the reliability ⁇ .
  • An example of switching between the second jet intensity estimated by the 207B and the second jet intensity has been described, but the present invention is not limited to this.
  • the jet intensities estimated by the jet intensities estimation units 207A and 207B may be weighted and the average value may be used as the jet intensities.
  • the estimation error of the jet intensity estimated from the specifications of the knock sensor 47 and the crank angle sensor 49 may be calculated in advance as the prior error distribution ⁇ , and this prior error distribution ⁇ may be used for the calculation of the reliability rate ⁇ .
  • FIG. 16 is a graph showing the correlation between the jet intensity and the initial combustion engine.
  • the horizontal axis shows the initial combustion engine (ignition timing-MFB02) obtained by a combustion analyzer based on the in-cylinder pressure of the main combustion chamber 14a.
  • the vertical axis shows the jet strength (maximum value of the differential pressure between the sub-combustion chamber and the main combustion chamber).
  • the method of estimating the jet intensity can be read as the method of estimating the initial combustion rate in jet ignition. Therefore, in the internal combustion engine control device according to the third embodiment, not only the jet intensity is estimated but also the initial combustion engine is estimated. As a result, by estimating the jet intensity, the initial combustion engine can be estimated and applied to overall engine control.
  • FIG. 17 is a diagram showing fluctuations in the in-cylinder pressure and torque of the main combustion chamber 14a in one combustion cycle.
  • the vertical axis shows the torque [Nm] and the in-cylinder pressure [MPa], and the horizontal axis shows the rotation angle of the crank shaft 48 in one combustion cycle.
  • the rotation speed change rate d ⁇ is estimated as the jet intensity.
  • the acceleration start timing of the crank shaft 48 is close to the top dead center, the combustion pressure is hardly converted into torque, and the torque value is zero. As a result, the pressure fluctuation may not be detected as the rotation fluctuation.
  • the jet intensity estimation unit 107 estimates the rotation speed change rate d ⁇ using the equation 8. After that, the jet strength estimation unit 107 calculates the in-cylinder pressure Pcomb of the main combustion chamber 14a in consideration of the pressure-torque conversion relationship by the piston mechanism based on Equation 4, and estimates the jet strength. Alternatively, the jet strength is estimated by calculating the in-cylinder pressure P comb using Equation 4 at each crank angle and calculating the slope dP / d ⁇ from the result.
  • the jet intensity estimation unit 107 uses the equation 4 only when it is determined that the jet generation timing is close to the top dead center, and the in-cylinder pressure P comb or its inclination dP / d ⁇ is used. May be calculated. As a result, the calculation load can be reduced.
  • the internal combustion engine control device 20 detects the end timing of the jet based on the crank information of the crank angle sensor 49.
  • the jet end timing is detected based on the signal of the ignition coil 16.
  • FIG. 18 is a diagram showing a state of change of the flame jet and an example of the pressure difference ⁇ P.
  • a graph of the pressure difference ⁇ P with respect to the crank angle is shown.
  • the reference numerals of explanatory views (a) to (c) showing the state of change of the flame jet shown in the upper part of FIG. 18 are added to the graph of the pressure difference ⁇ P.
  • the sub-combustion chamber is abbreviated as "sub-combustion chamber”
  • the main combustion chamber 14a is abbreviated as "main chamber”.
  • the arrows shown in the explanatory views (a) to (c) indicate the propagation direction of the flame.
  • the piston 18 begins to descend through the top dead center, but a flame is ejected from the sub-combustion chamber to the main combustion chamber 14a.
  • the pressure difference ⁇ P shows a positive value.
  • the flame jet ejected into the main combustion chamber 14a burns the air-fuel mixture in the main combustion chamber 14a, and the piston 18 descends. Then, the pressure in the sub-combustion chamber becomes a negative pressure. At this time, it can be seen from the graph at the bottom of FIG. 18 that the pressure difference ⁇ P shows a negative value. Therefore, a phenomenon occurs in which a flame blows back from the main combustion chamber 14a to the sub-combustion chamber. The fact that the blowback has occurred suggests that the jet has already ignited the air-fuel mixture in the main combustion chamber 14a. Therefore, the calculation of the rotation speed change rate d ⁇ is stopped at the time when this blowback is detected, that is, at the jet end time tburn . Therefore, the rotation speed change rate d ⁇ is calculated by the following equation 11.
  • the jet intensity estimation unit changes the rotation speed based on the rotation speed change amount ⁇ between the acceleration start time t acc or the jet start time t jet and the jet end time t burn .
  • the rate d ⁇ is calculated.
  • crank angle is 0 to 20 [deg. It falls within the range of [ATDC].
  • crank angle is 0 to 20 [deg. When the angle is retarded from the range of [ATDC], the flame does not blow back from the main combustion chamber 14a to the sub-combustion chamber because it has already entered the expansion stroke.
  • the crank angle is 0 to 20 [deg. If the angle is advanced beyond the range of [ATDC], the pressure in the engine 100 becomes too high, which is a condition outside the applicable range.
  • FIG. 19 is a first control time chart for explaining the detection of the combustion timing. Changes in the ignition signal and the secondary discharge current are shown in order from the top of FIG. The horizontal axis in FIG. 8 represents time.
  • the internal combustion engine control device outputs an ignition signal to the ignition coil 16.
  • the pulse width of the ignition signal is expressed as the charge period ct, and the primary coil is energized during the charge period ct.
  • the internal combustion engine control device controls the start of discharge of the spark plug 17 by lowering the ignition signal after the lapse of the charge period tk. In the spark plug 17, discharge is performed between the electrodes over the discharge period td.
  • the internal combustion engine control device detects the current change timing of the secondary discharge current based on the value of the secondary discharge current at the time of discharge between the electrodes fed back from the spark plug 17. Crank angle is 0 to 20 [deg.
  • the flame blowback period represented as [ATDC] the flame blows back from the main combustion chamber 14 to the sub chamber 8, so that the value of the secondary discharge current changes drastically.
  • the internal combustion engine control device detects the time when the value of the secondary discharge current changes drastically as the blowback time tburn .
  • both the start and end timings of the jet can be accurately detected, and the rotation speed change rate d ⁇ is brought closer to the actual rotation speed behavior. Can be done. As a result, the accuracy of estimating the jet strength can be improved.
  • FIG. 20 is a schematic configuration diagram showing an enlarged configuration around the auxiliary chamber of the internal combustion engine according to the modified example.
  • the internal combustion engine 100 shown in FIG. 1 is a passive internal combustion engine in which an injector 13 is provided on a side surface of a cylinder 14 and only a spark plug 17 is installed in an auxiliary chamber 8.
  • the internal combustion engine to which the internal combustion engine control device of the present invention is applied is not limited to the passive type shown in FIG.
  • an active type internal combustion engine in which the injector 13C is installed in the sub chamber 8 as shown in FIG. 20 may be applied. Then, the injector 13C directly injects fuel into the sub chamber 8.
  • the air-fuel ratio in the sub chamber 8 is controlled so that the ignitability is good by the air supplied from the main combustion chamber 14a side through the sub chamber injection hole 8a and the fuel supplied from the injector 13C. Can be done. As a result, it becomes possible to improve the combustion rest.
  • each of the above-described embodiments describes the configurations of the apparatus and the system in detail and concretely in order to explain the present invention in an easy-to-understand manner, and is not necessarily limited to those including all the described configurations. Further, it is possible to replace a part of the configuration of the embodiment described here with the configuration of another embodiment, and further, it is possible to add the configuration of another embodiment to the configuration of one embodiment. It is possible. It is also possible to add, delete, or replace a part of the configuration of each embodiment with another configuration.
  • control lines and information lines indicate what is considered necessary for explanation, and not all control lines and information lines are necessarily shown on the product. In practice, it can be considered that almost all configurations are interconnected.

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Abstract

This internal combustion engine control device comprises: an ignition time estimation unit, a crank angle information acquisition unit, a rotation fluctuation acquisition unit, and a jet intensity acquisition unit. The ignition time estimation unit estimates an ignition time on the basis of a knock sensor signal detected by a knock sensor. The rotation fluctuation acquisition unit calculates, on the basis of crank angle information, a rotational speed variation that is generated later than the ignition time. The jet intensity estimation unit calculates a rotational speed change rate that is generated later than the ignition time on the basis of the rotational speed variation calculated by the rotation fluctuation acquisition unit and the ignition time estimated by the ignition time estimation unit, and estimates jet intensity.

Description

内燃機関制御装置Internal combustion engine controller
　本発明は、内燃機関制御装置に関するものである。 The present invention relates to an internal combustion engine control device.
　従来、燃焼室内で燃料と空気の混合気を形成させ、点火または自着火により燃焼させるガソリンエンジンが知られている。この種類のエンジンの熱効率を向上させる技術として、数ｃｃの微小空間である副燃焼室で混合気を点火し、火炎ジェットを主燃焼室に噴射させる副室式火炎ジェット点火（以降、副室燃焼と称す）システムがある。 Conventionally, a gasoline engine is known in which a mixture of fuel and air is formed in a combustion chamber and burned by ignition or self-ignition. As a technique for improving the thermal efficiency of this type of engine, a sub-chamber type flame jet ignition (hereinafter, sub-chamber combustion) in which an air-fuel mixture is ignited in a sub-combustion chamber, which is a minute space of several cc, and a flame jet is injected into the main combustion chamber. There is a system (called).
　一般的なガソリンエンジンでは，主燃焼室上部に点火プラグが、その先端を燃焼室に露出する形で固定されている。そして、燃焼開始時には、点火プラグから放電による火花を発生させて、主燃焼室内の混合気へ直接点火を行う。 In a general gasoline engine, a spark plug is fixed to the upper part of the main combustion chamber so that the tip is exposed to the combustion chamber. Then, at the start of combustion, sparks due to electric discharge are generated from the spark plug to directly ignite the air-fuel mixture in the main combustion chamber.
　一方、副室燃焼では、燃焼室上部に副室を設け、点火プラグは副室内に露出する形で固定される。この副室には、主燃焼室に連通する副室噴射孔が設けられている。燃焼開始時は、まず副室内部にて混合気への点火が行われる。そして、副室内の燃焼発生後、副室噴射孔から主燃焼室側に向けて高温かつ未燃混合気を含んだジェットが噴出し、このジェットにより主燃焼室側の混合気を着火させる。主燃焼室では多点で同時に着火が起き、副室を用いない場合に比べて急速に燃焼が進行するため、燃焼の安定性が向上する。 On the other hand, in the case of combustion in the sub-chamber, a sub-chamber is provided in the upper part of the combustion chamber, and the spark plug is fixed so as to be exposed in the sub-chamber. This sub-chamber is provided with a sub-chamber injection hole that communicates with the main combustion chamber. At the start of combustion, the air-fuel mixture is first ignited in the sub-chamber. Then, after combustion occurs in the sub-chamber, a jet containing a high temperature and unburned air-fuel mixture is ejected from the sub-chamber injection hole toward the main combustion chamber side, and the air-fuel mixture on the main combustion chamber side is ignited by this jet. In the main combustion chamber, ignition occurs at multiple points at the same time, and combustion progresses more rapidly than when the sub chamber is not used, so combustion stability is improved.
　副室燃焼により、理論空燃比よりも燃料が薄い混合気を燃焼させるリーン燃焼を、より高い希釈状態で実施することが可能となり、混合気の比熱比増加による理論熱効率の向上や、ポンプ損失の低下により、熱効率が向上する。また、ノッキングなどの異常燃焼が発生する前に、当該異常燃焼発生領域に燃焼ガスを到達させることができ、その結果ノッキング抑制効果も得られる。これにより高負荷領域でも最適な点火時期を取ることができ、副室を用いない場合に比べて排気損失が低減、熱効率が更に向上する。 The sub-chamber combustion makes it possible to carry out lean combustion, which burns an air-fuel mixture whose fuel is thinner than the theoretical air-fuel ratio, in a higher dilution state. The reduction improves thermal efficiency. Further, the combustion gas can reach the abnormal combustion generation region before the abnormal combustion such as knocking occurs, and as a result, the knocking suppression effect can be obtained. As a result, the optimum ignition timing can be taken even in a high load region, the exhaust loss is reduced, and the thermal efficiency is further improved as compared with the case where the sub chamber is not used.
　また、副燃焼室を備えた内燃機関を制御する技術としては、例えば、特許文献１に記載されているようなものがある。特許文献１には、副燃焼室の圧力を検出する圧力センサと、内燃機関の運転状態および検出された副燃焼室における圧力に応じて点火プラグの点火を制御する点火制御部とを備えた技術が記載されている。 Further, as a technique for controlling an internal combustion engine provided with an auxiliary combustion chamber, for example, there is a technique as described in Patent Document 1. Patent Document 1 includes a technology including a pressure sensor that detects the pressure in the sub-combustion chamber and an ignition control unit that controls ignition of the spark plug according to the operating state of the internal combustion engine and the detected pressure in the sub-combustion chamber. Is described.
特開２０１８－１７８９６６号公報JP-A-2018-178966
　しかしながら、特許文献１に記載された技術では、副室の圧力を検出する圧力センサが必要となり、システコストが増大する、という問題を有していた。 However, the technique described in Patent Document 1 has a problem that a pressure sensor for detecting the pressure in the sub-chamber is required and the system cost increases.
　また、副室から噴出するジェットの強度が高いほど、混合気への安定着火が可能となるが、ジェット強度が高過ぎると、副室壁面や主燃焼室壁面への熱損失が増加し、その結果、燃料消費量が増大し、副室燃焼による燃費低減効果が減少する恐れがある。そして、ジェット強度が更に増加すると、ジェット噴出による主燃焼室の圧力変動がノッキングを誘発してしまう恐れもある。したがって、燃焼安定性と熱損失のバランスを取りながら、ジェット強度を適切な範囲に調整するために、ジェット強度を正確に推定することが求められる。 Further, the higher the strength of the jet ejected from the sub chamber, the more stable ignition of the air-fuel mixture becomes possible. However, if the jet strength is too high, the heat loss to the wall surface of the sub chamber and the wall surface of the main combustion chamber increases. As a result, fuel consumption may increase and the effect of reducing fuel consumption due to combustion in the sub-chamber may decrease. If the jet strength is further increased, the pressure fluctuation in the main combustion chamber due to the jet ejection may induce knocking. Therefore, it is required to accurately estimate the jet strength in order to adjust the jet strength to an appropriate range while balancing combustion stability and heat loss.
　本目的は、上記の問題点を考慮し、副室の圧力を検出する圧力センサを用いることなくジェット強度を推定することができる内燃機関制御装置を提供することにある。 The purpose of this object is to provide an internal combustion engine control device that can estimate the jet strength without using a pressure sensor that detects the pressure in the sub chamber in consideration of the above problems.
　上記課題を解決し、目的を達成するため、内燃機関制御装置は、ピストンに面する主燃焼室と、副燃焼室と、点火プラグと、クランク軸と、クランク角センサと、シリンダと、ノックセンサと、を備えた内燃機関を制御する。また、副燃焼室は、主燃焼室に連通する。点火プラグは、副燃焼室の内部に取り付けられる。クランク軸は、ピストンに連結される。クランク角センサは、クランク軸の回転角度を検出する。シリンダは、主燃焼室を形成する。ノックセンサは、シリンダの振動を検出する。
　内燃機関制御装置は、着火時刻推定部と、クランク角情報取得部と、回転変動取得部と、ジェット強度推定部と、を備えている。
　着火時刻推定部は、ノックセンサが検出したノックセンサ信号に基づいて、副燃焼室から噴射されたジェットによる主燃焼室の混合気の着火時刻を推定する。クランク角情報取得部は、クランク角センサが検出したクランク角情報を取得する。回転変動取得部は、クランク角情報に基づいて、着火時刻よりも後に発生する回転数変化量を算出する。ジェット強度推定部は、回転変動取得部が算出した回転数変化量と着火時刻推定部が推定した着火時刻に基づいて、着火時刻より後に発生する回転数変化率を算出し、ジェット強度を推定する。 In order to solve the above problems and achieve the purpose, the internal combustion engine control device includes a main combustion chamber facing the piston, a sub-combustion chamber, a spark plug, a crank shaft, a crank angle sensor, a cylinder, and a knock sensor. And controls an internal combustion engine equipped with. In addition, the sub-combustion chamber communicates with the main combustion chamber. The spark plug is mounted inside the sub-combustion chamber. The crank shaft is connected to the piston. The crank angle sensor detects the rotation angle of the crank shaft. The cylinder forms the main combustion chamber. The knock sensor detects the vibration of the cylinder.
The internal combustion engine control device includes an ignition time estimation unit, a crank angle information acquisition unit, a rotation fluctuation acquisition unit, and a jet intensity estimation unit.
The ignition time estimation unit estimates the ignition time of the air-fuel mixture in the main combustion chamber by the jet injected from the sub-combustion chamber based on the knock sensor signal detected by the knock sensor. The crank angle information acquisition unit acquires the crank angle information detected by the crank angle sensor. The rotation fluctuation acquisition unit calculates the amount of rotation speed change that occurs after the ignition time based on the crank angle information. The jet intensity estimation unit estimates the jet intensity by calculating the rotation speed change rate that occurs after the ignition time based on the rotation speed change amount calculated by the rotation fluctuation acquisition unit and the ignition time estimated by the ignition time estimation unit. ..
　上記構成の内燃機関制御装置によれば、副室の圧力を検出する圧力センサを用いることなくジェット強度を正確に推定することができる。 According to the internal combustion engine control device having the above configuration, the jet strength can be accurately estimated without using a pressure sensor that detects the pressure in the sub chamber.
第１の実施の形態例にかかる内燃機関制御装置が搭載された内燃機関のシステム構成を示す概略構成図である。It is a schematic block diagram which shows the system structure of the internal combustion engine equipped with the internal combustion engine control device which concerns on the 1st Embodiment example. 第１の実施の形態例にかかる内燃機関制御装置が搭載された内燃機関のシリンダ周りの構成を示す概略構成図である。It is a schematic block diagram which shows the structure around the cylinder of the internal combustion engine which mounted the internal combustion engine control device which concerns on the 1st Embodiment example. 第１の実施の形態例にかかる内燃機関制御装置の構成を示すブロック図である。It is a block diagram which shows the structure of the internal combustion engine control device which concerns on the 1st Embodiment example. 第１の実施の形態例にかかる内燃機関制御装置におけるジェット強度の推定処理の構成を示すブロック図である。It is a block diagram which shows the structure of the jet intensity estimation processing in the internal combustion engine control device which concerns on the 1st Embodiment example. ジェット強度の違いによる燃焼消費量及び熱損失量を説明する図であり、図５Ａはジェット強度の違いによる副室の圧力と主燃焼室の圧力との差を示す図である。図５Ｂは、ジェット強度の違いと燃焼消費率の関係を示す図、図５Ｃは、ジェット強度の違いと熱損失量の関係を示す図である。It is a figure explaining the combustion consumption amount and the heat loss amount by the difference of a jet intensity, and FIG. 5A is a figure which shows the difference between the pressure of a sub chamber and the pressure of a main combustion chamber by a difference of a jet intensity. FIG. 5B is a diagram showing the relationship between the difference in jet intensity and the combustion consumption rate, and FIG. 5C is a diagram showing the relationship between the difference in jet intensity and the amount of heat loss. 燃焼１サイクル当たりの副室及び主燃焼室の圧力、圧力差、回転数及び振動（加速度）の変化について示すものである図６（ａ）は副室の圧力、図６（ｂ）は主燃焼室の圧力、図６（ｃ）は圧力差、図６（ｄ）は回転数、図６（ｅ）は振動（加速度）を締めている。The changes in pressure, pressure difference, rotation speed and vibration (acceleration) of the auxiliary chamber and the main combustion chamber per one combustion cycle are shown. FIG. 6 (a) shows the pressure in the auxiliary chamber, and FIG. 6 (b) shows the main combustion. The pressure in the chamber, FIG. 6 (c) is the pressure difference, FIG. 6 (d) is the rotation speed, and FIG. 6 (e) is the vibration (acceleration). 従来の回転数変化率の推定方法と、第１の実施の形態例にかかる内燃機関制御装置における回転数変化率の推定方法を示すイメージ図である。It is an image diagram which shows the conventional method of estimating the rotation speed change rate, and the method of estimating the rotation speed change rate in the internal combustion engine control device which concerns on 1st Embodiment example. 第１の実施の形態例にかかる内燃機関制御装置におけるノックセンサ信号の信号処理を示すもので、図８（ａ）はノックセンサの出力値を示す波形、図８（ｂ）はノックセンサ信号に対してフィルタ処理を行ったフィルタ出力値を示す波形である。図８（ｃ）は、フィルタ出力値の絶対値を示す図である。The signal processing of the knock sensor signal in the internal combustion engine control device according to the first embodiment is shown, FIG. 8A shows a waveform showing an output value of the knock sensor, and FIG. 8B shows a knock sensor signal. On the other hand, it is a waveform which shows the filter output value which performed the filter processing. FIG. 8C is a diagram showing an absolute value of the filter output value. 従来のジェット強度の推定結果と第１の実施の形態例にかかる内燃機関制御装置が推定したジェット強度の推定結果の精度を示すグラフである。It is a graph which shows the accuracy of the estimation result of the jet intensity estimated by the internal combustion engine control device which concerns on the 1st Embodiment example of the estimation result of the conventional jet intensity. 第１の実施の形態例にかかる内燃機関制御装置におけるジェット強度の補正制御動作を示すフローチャートである。It is a flowchart which shows the correction control operation of the jet strength in the internal combustion engine control device which concerns on the 1st Embodiment example. 第１の実施の形態例にかかる内燃機関制御装置におけるジェット強度の増減処理を示すもので、図１１Ａは増減処理の一例を示すグラフ、図１１Ｂは増減処理の他の例を示すグラフである。FIG. 11A is a graph showing an example of the increase / decrease process, and FIG. 11B is a graph showing another example of the increase / decrease process, showing the jet intensity increase / decrease process in the internal combustion engine control device according to the first embodiment. 第１の実施の形態例にかかる内燃機関制御装置におけるジェット強度の増減処理を示すもので、図１２Ａは増減処理の一例を示すグラフ、図１２Ｂは増減処理の他の例を示すグラフである。FIG. 12A is a graph showing an example of the increase / decrease process, and FIG. 12B is a graph showing another example of the increase / decrease process, showing the jet intensity increase / decrease process in the internal combustion engine control device according to the first embodiment. 第２の実施の形態例にかかる内燃機関制御装置におけるジェット強度の推定処理の構成を示すブロック図である。It is a block diagram which shows the structure of the jet intensity estimation processing in the internal combustion engine control device which concerns on the 2nd Embodiment example. 第２の実施の形態例にかかる内燃機関制御装置におけるエンジン運転条件ごとのジェット強度推定時のノックセンサ振幅信頼率を示すマップである。It is a map which shows the knock sensor amplitude reliability rate at the time of jet strength estimation for every engine operation condition in the internal combustion engine control device which concerns on 2nd Embodiment example. 第２の実施の形態例にかかる内燃機関制御装置の第２ジェット強度推定部によるジェット強度の推定方法を示す図である。It is a figure which shows the method of estimating the jet intensity by the 2nd jet intensity estimation part of the internal combustion engine control device which concerns on 2nd Embodiment example. ジェット強度と初期燃焼機関の相関関係を示すグラフである。It is a graph which shows the correlation of a jet intensity and an initial combustion engine. 燃焼１サイクルにおける主燃焼室の筒内圧及びトルクの変動を示す図である。It is a figure which shows the fluctuation of the cylinder pressure and torque of the main combustion chamber in one combustion cycle. 火炎ジェットの変化の様子と、圧力差ΔＰの例を示す図である。It is a figure which shows the state of the change of a flame jet, and the example of a pressure difference ΔP. 第５の実施の形態例にかかる内燃機関制御装置における燃焼タイミングの検出を説明するための制御タイムチャートである。It is a control time chart for demonstrating the detection of the combustion timing in the internal combustion engine control apparatus which concerns on 5th Embodiment example. 変形例にかかる内燃機関の副室周りの構成を拡大して示す概略構成図である。It is a schematic block diagram which shows the structure around the auxiliary chamber of the internal combustion engine which concerns on the modification by being enlarged.
　以下、実施の形態例にかかる内燃機関制御装置について、図１～図２０を参照して説明する。なお、各図において共通の部材には、同一の符号を付している。 Hereinafter, the internal combustion engine control device according to the embodiment will be described with reference to FIGS. 1 to 20. The common members in each figure are designated by the same reference numerals.
１．第１の実施の形態例
　まず、第１の実施の形態例（以下、「本例」という）にかかる内燃機関制御装置の構成例について説明する。 1. 1. Example of First Embodiment First, a configuration example of an internal combustion engine control device according to an example of the first embodiment (hereinafter, referred to as “this example”) will be described.
１－１．内燃機関の構成例
　まず、図１及び図２を参照して内燃機関の構成例について説明する。
　図１は、本例の内燃機関のシステム構成を示す概略構成図である。図２は、内燃機関のシリンダ周りの構成を示す概略構成図である。 1-1. Configuration Example of Internal Combustion Engine First, a configuration example of an internal combustion engine will be described with reference to FIGS. 1 and 2.
FIG. 1 is a schematic configuration diagram showing a system configuration of the internal combustion engine of this example. FIG. 2 is a schematic configuration diagram showing a configuration around a cylinder of an internal combustion engine.
　図１に示す内燃機関１００は、ガソリンからなる燃料を筒内に直接噴射する筒内噴射型の内燃機関（直噴エンジン）である。内燃機関１００は、吸入行程、圧縮行程、燃焼（膨張）行程、排気行程の４行程を繰り返す４サイクルエンジンである。さらに、内燃機関１００は、例えば、４つの気筒（シリンダ）を備えた多気筒エンジンである。なお、内燃機関１００が有する気筒の数は、４つに限定されるものではなく、６つ又は８つ以上の気筒を有していてもよい。 The internal combustion engine 100 shown in FIG. 1 is an in-cylinder injection type internal combustion engine (direct injection engine) that directly injects fuel made of gasoline into the cylinder. The internal combustion engine 100 is a four-cycle engine that repeats four strokes of an intake stroke, a compression stroke, a combustion (expansion) stroke, and an exhaust stroke. Further, the internal combustion engine 100 is, for example, a multi-cylinder engine including four cylinders (cylinders). The number of cylinders of the internal combustion engine 100 is not limited to four, and may have six or eight or more cylinders.
　図１に示すように、内燃機関１００は、エアフローセンサ１と、電子制御スロットル弁２と、吸気圧センサ３と、過給機４と、インタークーラ７と、シリンダ１４と、備えている。エアフローセンサ１、電子制御スロットル弁２、吸気圧センサ３、過給機４のコンプレッサ４ａ、インタークーラ７は、吸気管６におけるシリンダ１４までの位置に配置されている。 As shown in FIG. 1, the internal combustion engine 100 includes an air flow sensor 1, an electronically controlled throttle valve 2, an intake pressure sensor 3, a supercharger 4, an intercooler 7, and a cylinder 14. The air flow sensor 1, the electronically controlled throttle valve 2, the intake pressure sensor 3, the compressor 4a of the supercharger 4, and the intercooler 7 are arranged at positions up to the cylinder 14 in the intake pipe 6.
　エアフローセンサ１は、吸入空気量と、吸気温度を計測する。電子制御スロットル弁２は、不図示の駆動モータにより開閉可能に駆動する。そして、運転者のアクセル操作に基づいて、電子制御スロットル弁２の開度が調整される。これにより、インタークーラ７やシリンダ１４に吸気される空気量を調整する。 The air flow sensor 1 measures the intake air amount and the intake air temperature. The electronically controlled throttle valve 2 is driven so as to be openable and closable by a drive motor (not shown). Then, the opening degree of the electronically controlled throttle valve 2 is adjusted based on the accelerator operation of the driver. As a result, the amount of air taken into the intercooler 7 and the cylinder 14 is adjusted.
　コンプレッサ４ａは、吸気を過給する過給機である。このコンプレッサ４ａは、後述するタービン４ｂにより回転力が伝達される。インタークーラ７は、シリンダ１４の上流側に配置され、電子制御スロットル弁２、エアフローセンサ１よりも下流側に配置されている。そして、インタークーラ７は、吸気を冷却する。 The compressor 4a is a supercharger that supercharges the intake air. A rotational force is transmitted to the compressor 4a by a turbine 4b, which will be described later. The intercooler 7 is arranged on the upstream side of the cylinder 14, and is arranged on the downstream side of the electronically controlled throttle valve 2 and the airflow sensor 1. Then, the intercooler 7 cools the intake air.
　また、内燃機関１００は、図１及び図２に示すように、シリンダ１４の筒内に燃料を噴射するインジェクタ１３と、点火エネルギを供給する点火コイル１６及び点火プラグ１７からなる点火装置と、副室８と、ノックセンサ４７がシリンダ１４ごとに設けられている。点火コイル１６は、内燃機関制御装置２０の制御の下、高電圧を生成し、点火プラグ１７に印加する。これにより、点火プラグ１７に火花が発生する。 Further, as shown in FIGS. 1 and 2, the internal combustion engine 100 includes an injector 13 for injecting fuel into the cylinder of the cylinder 14, an ignition device 16 including an ignition coil 16 for supplying ignition energy, and an ignition plug 17, and a sub. A chamber 8 and a knock sensor 47 are provided for each cylinder 14. The ignition coil 16 generates a high voltage under the control of the internal combustion engine control device 20 and applies it to the spark plug 17. As a result, sparks are generated in the spark plug 17.
　また、図２に示すように、点火プラグ１７は、シリンダ１４に設けられた副室８内に配置されている。中空の副室８は、シリンダ１４の筒内に挿入されている。そのため、本例の内燃機関１００は、シリンダ１４の筒内に形成された主燃焼室１４ａと、副室８により形成される副燃焼室に分けられる。副室８は、その先端部が主燃焼室１４ａ内に露出する状態でシリンダヘッドに固定されている。副室８の先端部には、主燃焼室１４ａと連通する副室噴射孔８ａが形成されている。副室８により形成される副燃焼室と主燃焼室１４ａは。副室噴射孔８ａにより連通する。そして、副室８内には、副室噴射孔８ａを介して主燃焼室１４ａから混合気が取り込まれる。 Further, as shown in FIG. 2, the spark plug 17 is arranged in the sub chamber 8 provided in the cylinder 14. The hollow sub chamber 8 is inserted into the cylinder of the cylinder 14. Therefore, the internal combustion engine 100 of this example is divided into a main combustion chamber 14a formed in the cylinder of the cylinder 14 and a sub-combustion chamber formed by the sub chamber 8. The sub chamber 8 is fixed to the cylinder head with its tip exposed in the main combustion chamber 14a. A sub-chamber injection hole 8a communicating with the main combustion chamber 14a is formed at the tip of the sub-chamber 8. The sub-combustion chamber and the main combustion chamber 14a formed by the sub-chamber 8 are. It communicates with the auxiliary chamber injection hole 8a. Then, the air-fuel mixture is taken into the sub-chamber 8 from the main combustion chamber 14a via the sub-chamber injection hole 8a.
　また、点火プラグ１７に発生した火花により副燃焼室内の混合気が燃焼する。そして、副室８内で生じた火炎は、副室噴射孔８ａを通過して主燃焼室１４ａに複数の火炎ジェットとして噴出し、主燃焼室１４ａ内の混合気を着火し、主燃焼が行われる。以下、副室噴射孔８ａから噴射される火炎ジェットを単にジェットと称す。これにより、主燃焼室１４ａでは、同時に多点で着火が発生し、副室８を用いない場合に比べて急速に燃焼が進行し、燃焼の安定性が向上する。以下、副室噴射孔８ａから噴射される火炎ジェットを単にジェットと称す。 In addition, the air-fuel mixture in the sub-combustion chamber is burned by the spark generated in the spark plug 17. Then, the flame generated in the sub chamber 8 passes through the sub chamber injection hole 8a and is ejected as a plurality of flame jets into the main combustion chamber 14a, ignites the air-fuel mixture in the main combustion chamber 14a, and the main combustion is performed. Will be. Hereinafter, the flame jet injected from the sub-chamber injection hole 8a is simply referred to as a jet. As a result, in the main combustion chamber 14a, ignition occurs at multiple points at the same time, combustion proceeds more rapidly than in the case where the sub chamber 8 is not used, and the stability of combustion is improved. Hereinafter, the flame jet injected from the sub-chamber injection hole 8a is simply referred to as a jet.
　また、点火コイル１６には、不図示の電圧センサが取り付けられている。電圧センサは、点火コイル１６の一次側電圧又は二次側電圧を計測する。そして、電圧センサが計測した電圧情報は、ＥＣＵ（Engine Control Unit）である内燃機関制御装置２０に送られる。 Further, a voltage sensor (not shown) is attached to the ignition coil 16. The voltage sensor measures the primary side voltage or the secondary side voltage of the ignition coil 16. Then, the voltage information measured by the voltage sensor is sent to the internal combustion engine control device 20 which is an ECU (Engine Control Unit).
　また、シリンダ１４のシリンダヘッドには、可変バルブ５が設けられている。図２に示すように、吸気側タイミング機構５ａと、排気側タイミング機構５ｂと、吸気バルブ３１と、排気バルブ３２とを有している。吸気バルブ３１は、シリンダ１４における吸気管６が接続される吸気ポートに配置され、排気バルブ３２は、シリンダ１４における後述する排気管１５が接続される排気ポートに配置される。 Further, the cylinder head of the cylinder 14 is provided with a variable valve 5. As shown in FIG. 2, it has an intake side timing mechanism 5a, an exhaust side timing mechanism 5b, an intake valve 31, and an exhaust valve 32. The intake valve 31 is arranged at the intake port to which the intake pipe 6 of the cylinder 14 is connected, and the exhaust valve 32 is arranged at the exhaust port of the cylinder 14 to which the exhaust pipe 15 described later is connected.
　可変バルブ５は、吸気側タイミング機構５ａと排気側タイミング機構５ｂにより吸気バルブ３１と排気バルブ３２の開弁及び閉弁磁気を調整する。これにより、シリンダ１４の筒内に流入する混合気、または筒内から排出する排気ガスが調整される。可変バルブ５を調整することにより、全シリンダ１４の吸気量及び内部ＥＧＲ量が調整される。 The variable valve 5 adjusts the valve opening and closing magnetism of the intake valve 31 and the exhaust valve 32 by the intake side timing mechanism 5a and the exhaust side timing mechanism 5b. As a result, the air-fuel mixture flowing into the cylinder of the cylinder 14 or the exhaust gas discharged from the cylinder is adjusted. By adjusting the variable valve 5, the intake amount and the internal EGR amount of all the cylinders 14 are adjusted.
　さらに、シリンダ１４の筒内には、ピストン１８が摺動可能に配置されている。ピストン１８は、シリンダ１４の筒内に流入した燃料とガスの混合気を圧縮する。そして、ピストン１８は、筒内に生じた燃焼圧力によりシリンダ１４の筒内を往復運動する。ピストン１８は、コンロッドを介してクランク軸４８が連結されている。 Further, the piston 18 is slidably arranged in the cylinder of the cylinder 14. The piston 18 compresses the mixture of fuel and gas that has flowed into the cylinder of the cylinder 14. Then, the piston 18 reciprocates in the cylinder of the cylinder 14 due to the combustion pressure generated in the cylinder. A crank shaft 48 is connected to the piston 18 via a connecting rod.
　また，クランク軸４８の角度を検出するための、クランク角センサ４９が設けられている。クランク角センサ４９は、クランク軸４８の周方向に所定の角度間隔（例えば、６ｄｅｇ）に設けられた歯を検出する。 Further, a crank angle sensor 49 is provided to detect the angle of the crank shaft 48. The crank angle sensor 49 detects teeth provided at predetermined angular intervals (for example, 6 deg) in the circumferential direction of the crank shaft 48.
　また、ノックセンサ４７は、シリンダ１４の側面部またはシリンダヘッドに取り付けられている。ノックセンサ４７は、シリンダ１４の振動を検出する加速度センサである。ノックセンサ４７を設ける位置は、シリンダ１４の側面部に限定されるものではなく、例えば、シリンダヘッドの上部等のシリンダ１４の振動を検出できる位置であればよい。ノックセンサ４７が検出したシリンダ１４の振動信号（加速度情報）は、後述する内燃機関制御装置（ＥＣＵ）２０に出力される。そして、ＥＣＵ２０は、ノックセンサ４７からの振動信号が予め設定されたノック閾値を超えたと判断した場合、ノッキングの発生を検出する。 Further, the knock sensor 47 is attached to the side surface portion of the cylinder 14 or the cylinder head. The knock sensor 47 is an acceleration sensor that detects the vibration of the cylinder 14. The position where the knock sensor 47 is provided is not limited to the side surface portion of the cylinder 14, and may be any position where vibration of the cylinder 14 can be detected, such as the upper part of the cylinder head. The vibration signal (acceleration information) of the cylinder 14 detected by the knock sensor 47 is output to the internal combustion engine control unit (ECU) 20, which will be described later. Then, when the ECU 20 determines that the vibration signal from the knock sensor 47 exceeds the preset knock threshold value, the ECU 20 detects the occurrence of knocking.
　インジェクタ１３は、後述する内燃機関制御装置（ＥＣＵ）２０に制御されて、シリンダ１４の筒内に燃料を噴射する。これにより、シリンダ１４における主燃焼室１４ａには、空気の燃料が混合された混合ガスが生成される。また、インジェクタ１３には、不図示の高圧燃料ポンプが接続されている。高圧燃料ポンプにより圧力が高められた燃料がインジェクタ１３に供給される。さらに、インジェクタ１３と高圧燃料ポンプとを接続する燃料配管には、燃料噴射圧力を計測するための燃料圧力センサが設けられている。 The injector 13 is controlled by an internal combustion engine control unit (ECU) 20, which will be described later, to inject fuel into the cylinder of the cylinder 14. As a result, a mixed gas mixed with air fuel is generated in the main combustion chamber 14a of the cylinder 14. A high-pressure fuel pump (not shown) is connected to the injector 13. The fuel whose pressure has been increased by the high-pressure fuel pump is supplied to the injector 13. Further, a fuel pressure sensor for measuring the fuel injection pressure is provided in the fuel pipe connecting the injector 13 and the high-pressure fuel pump.
　なお、本例では、インジェクタ１３をシリンダ１４に設けた例を説明したが、これに限定されるものではない。例えば、吸気管６にポート噴射用インジェクタ１３Ｂを取り付け、ポート噴射用インジェクタ１３Ｂから吸気ポートに燃料を噴射させてもよい。 In this example, an example in which the injector 13 is provided on the cylinder 14 has been described, but the present invention is not limited to this. For example, the port injection injector 13B may be attached to the intake pipe 6, and fuel may be injected from the port injection injector 13B into the intake port.
　図１に示すように、排気管１５には、タービン４ｂ、電子制御ウエイストゲート弁１１、三元触媒１０、空燃比センサ９が設けられている。タービン４ｂは、排気管１５を通過する排気ガスにより回転し、コンプレッサ４ａに回転力を伝える。電子制御ウエイストゲート弁１１は、タービン４ｂに流れる排気流路を調整する。 As shown in FIG. 1, the exhaust pipe 15 is provided with a turbine 4b, an electronically controlled wastegate valve 11, a three-way catalyst 10, and an air-fuel ratio sensor 9. The turbine 4b is rotated by the exhaust gas passing through the exhaust pipe 15 and transmits the rotational force to the compressor 4a. The electronically controlled wastegate valve 11 adjusts the exhaust flow path flowing through the turbine 4b.
　三元触媒１０は、酸化・還元反応により排気ガスに含まれる有害物質を浄化する。また、空燃比センサ９は、三元触媒１０の上流側に配置されている。そして、空燃比センサ９は、排気管１５を通る排気ガスの空燃比を検出する。 The three-way catalyst 10 purifies harmful substances contained in the exhaust gas by an oxidation / reduction reaction. Further, the air-fuel ratio sensor 9 is arranged on the upstream side of the three-way catalyst 10. Then, the air-fuel ratio sensor 9 detects the air-fuel ratio of the exhaust gas passing through the exhaust pipe 15.
　また、内燃機関１００は、三元触媒１０の下流から、コンプレッサ４ａの上流で、かつエアフローセンサ１よりも下流側の位置に排気ガス（ＥＧＲガス）を還流させるＥＧＲ流路管４０を備えている。ＥＧＲ流路管４０には、ＥＧＲクーラ４２と、ＥＧＲバルブ４１と、差圧センサ４３が設けられている。 Further, the internal combustion engine 100 includes an EGR flow path tube 40 that recirculates exhaust gas (EGR gas) from the downstream side of the three-way catalyst 10 to the upstream side of the compressor 4a and the downstream side of the air flow sensor 1. .. The EGR flow path tube 40 is provided with an EGR cooler 42, an EGR valve 41, and a differential pressure sensor 43.
　ＥＧＲクーラ４２は、ＥＧＲガスを冷却する。ＥＧＲバルブ４１は、ＥＧＲ流路管４０を通るＥＧＲガスの流量を調節するＥＧＲ流量を制御する。ＥＧＲバルブ４１の近傍には、ＥＧＲバルブ４１の前後の差圧を検出する差圧センサ４３が取り付けられている。ここで、ＥＧＲバルブ４１の前後の差圧とは、ＥＧＲ流路管４０におけるＥＧＲバルブ４１の上流側の圧力と下流側の圧力との差である。ＥＧＲ温度センサ４４は、ＥＧＲバルブ４１の下流に配置されている。ＥＧＲ温度センサ４４は、ＥＧＲ流路管４０を流れるＥＧＲガスの温度を検出する。 The EGR cooler 42 cools the EGR gas. The EGR valve 41 controls the EGR flow rate that regulates the flow rate of the EGR gas passing through the EGR flow path pipe 40. A differential pressure sensor 43 that detects the differential pressure before and after the EGR valve 41 is attached in the vicinity of the EGR valve 41. Here, the differential pressure before and after the EGR valve 41 is the difference between the pressure on the upstream side and the pressure on the downstream side of the EGR valve 41 in the EGR flow path pipe 40. The EGR temperature sensor 44 is arranged downstream of the EGR valve 41. The EGR temperature sensor 44 detects the temperature of the EGR gas flowing through the EGR flow path tube 40.
　三元触媒１０で浄化された排気ガスの一部は、外部へ排出されずに、ＥＧＲ流路管４０へ流入し、ＥＧＲガスとして利用される。ＥＧＲガスは、ＥＧＲクーラ４２及びＥＧＲバルブ４１を通過後、コンプレッサ４ａの上流にて、吸気された新気と合流する。その後、ＥＧＲガスと新気の混合ガスは、インタークーラ７及び電子制御スロットル弁２を通過後に、シリンダ１４に流入する。 A part of the exhaust gas purified by the three-way catalyst 10 flows into the EGR flow path pipe 40 without being discharged to the outside, and is used as EGR gas. After passing through the EGR cooler 42 and the EGR valve 41, the EGR gas joins the fresh air taken in upstream of the compressor 4a. After that, the mixed gas of EGR gas and fresh air flows into the cylinder 14 after passing through the intercooler 7 and the electronically controlled throttle valve 2.
　また、エアフローセンサ１、吸気圧センサ３、ノックセンサ４７等の各センサが検出した信号は、ＥＣＵ（Engine Control Unit）である内燃機関制御装置２０に送られる。また、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アクセル開度センサ１２が検出した信号も内燃機関制御装置２０に送られる。 Further, the signals detected by each sensor such as the air flow sensor 1, the intake pressure sensor 3, and the knock sensor 47 are sent to the internal combustion engine control device 20 which is an ECU (Engine Control Unit). Further, the amount of depression of the accelerator pedal, that is, the signal detected by the accelerator opening sensor 12 that detects the accelerator opening is also sent to the internal combustion engine control device 20.
　内燃機関制御装置２０は、アクセル開度センサ１２の主力信号に基づいて、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１００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、内燃機関制御装置２０は、不図示のクランク角度センサの出力信号に基づいて、内燃機関１００の回転速度を演算する。そして、内燃機関制御装置２０は、各種センサの出力から得られる内燃機関１００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１００の主要な作動量を最適に演算する。 The internal combustion engine control device 20 calculates the required torque based on the main signal of the accelerator opening sensor 12. That is, the accelerator opening degree sensor 12 is used as a required torque detection sensor for detecting the required torque for the internal combustion engine 100. Further, the internal combustion engine control device 20 calculates the rotation speed of the internal combustion engine 100 based on the output signal of a crank angle sensor (not shown). Then, the internal combustion engine control device 20 optimally optimizes the main operating amounts of the internal combustion engine 100 such as air flow rate, fuel injection amount, ignition timing, and fuel pressure, based on the operating state of the internal combustion engine 100 obtained from the outputs of various sensors. Calculate.
　内燃機関制御装置２０により演算した燃料噴射量は、開弁パルス信号に変換され、インジェクタ１３に出力される。また、内燃機関制御装置２０により演算された点火時期は、点火信号として点火プラグ１７に出力される。さらに、内燃機関制御装置２０により演算されたスロットル開度は、スロットル駆動信号として電子制御スロットル弁２に出力される。また、内燃機関制御装置２０により演算されたＥＧＲバルブ開度は、ＥＧＲバルブ開度駆動信号として、ＥＧＲバルブ４１に出力される。 The fuel injection amount calculated by the internal combustion engine control device 20 is converted into a valve opening pulse signal and output to the injector 13. Further, the ignition timing calculated by the internal combustion engine control device 20 is output to the spark plug 17 as an ignition signal. Further, the throttle opening calculated by the internal combustion engine control device 20 is output to the electronically controlled throttle valve 2 as a throttle drive signal. Further, the EGR valve opening degree calculated by the internal combustion engine control device 20 is output to the EGR valve 41 as an EGR valve opening degree driving signal.
１－２．内燃機関制御装置２０の構成例
　次に、図３を参照して内燃機関制御装置２０の構成例について説明する。
　図３は、内燃機関制御装置２０の構成を示すブロック図である。 1-2. Configuration Example of Internal Combustion Engine Control Device 20 Next, a configuration example of the internal combustion engine control device 20 will be described with reference to FIG.
FIG. 3 is a block diagram showing the configuration of the internal combustion engine control device 20.
　図３に示すように、ＥＣＵ（Engine Control Unit）である内燃機関制御装置２０は、入力回路２１と、入出力ポート２２と、ＲＡＭ（Random Access Memory）２３ｃと、ＲＯＭ（Read Only Memory）２３ｂと、ＣＰＵ（Central Processing Unit）２３ａを有する。また、内燃機関制御装置２０は、点火制御部２４と、を有している。 As shown in FIG. 3, the internal combustion engine control device 20 which is an ECU (Engine Control Unit) includes an input circuit 21, an input / output port 22, a RAM (RandomAccessMemory) 23c, and a ROM (ReadOnlyMemory) 23b. , CPU (Central Processing Unit) 23a. Further, the internal combustion engine control device 20 has an ignition control unit 24.
　入力回路２１には、エアフローセンサ１からの吸入流量、吸気圧センサ３からの吸気圧、電圧センサからのコイル一次電圧又は二次電圧が入力される。また、入力回路２１には、アクセル開度、回転数、湿度、空気量、クランク角度、点火装置情報、ノックセンサ情報等の各種センサが計測した情報が入力される。 The suction flow rate from the air flow sensor 1, the intake pressure from the intake pressure sensor 3, and the coil primary voltage or secondary voltage from the voltage sensor are input to the input circuit 21. Further, information measured by various sensors such as accelerator opening degree, rotation speed, humidity, air amount, crank angle, ignition device information, and knock sensor information is input to the input circuit 21.
　入力回路２１は、入力された信号に対してノイズ除去等の信号処理を行って、入出力ポート２２へ送る。入出力ポート２２の入力ポートに入力された値はＲＡＭ２３ｃに格納される。 The input circuit 21 performs signal processing such as noise reduction on the input signal and sends it to the input / output port 22. The value input to the input port of the input / output port 22 is stored in the RAM 23c.
　ＲＯＭ２３ｂには、ＣＰＵ２３ａにより実行される各種演算処理の内容を記述した制御プログラムや、各処理に用いられるＭＡＰやデータテーブル等が記憶されている。ＲＡＭ２３ｃには、入出力ポート２２の入力ポートに入力された値や、制御プログラムに従って演算された各アクチュエータの操作量を表す値を格納する格納領域が設けられている。また、ＲＡＭ２３ｃに格納された各アクチュエータの操作量を表す値は、入出力ポート２２の出力ポートに送られる。 The ROM 23b stores a control program that describes the contents of various arithmetic processes executed by the CPU 23a, a MAP, a data table, and the like used for each process. The RAM 23c is provided with a storage area for storing the value input to the input port of the input / output port 22 and the value representing the operation amount of each actuator calculated according to the control program. Further, a value representing the operation amount of each actuator stored in the RAM 23c is sent to the output port of the input / output port 22.
　入出力ポート２２の出力ポートにセットされた点火信号は、点火制御部２４を経て、点火コイル１６に送られる。点火制御部２４は、点火コイル１６への通電時期や通電時間を制御する。さらに、点火制御部２４は、点火プラグ１７での放電エネルギ制御を行う。 The ignition signal set in the output port of the input / output port 22 is sent to the ignition coil 16 via the ignition control unit 24. The ignition control unit 24 controls the energization timing and energization time of the ignition coil 16. Further, the ignition control unit 24 controls the discharge energy at the spark plug 17.
　なお、本例では、内燃機関制御装置２０に点火制御部２４を設けた例を説明したが、これに限定されるものではない。例えば、点火制御部２４の一部、あるいは点火制御部２４の全てを内燃機関制御装置２０とは異なる制御装置に実装してもよい。 In this example, an example in which the internal combustion engine control device 20 is provided with the ignition control unit 24 has been described, but the present invention is not limited to this. For example, a part of the ignition control unit 24 or all of the ignition control unit 24 may be mounted on a control device different from the internal combustion engine control device 20.
　また、内燃機関制御装置２０は、各種センサからの出力信号に基づいて、副室８の副室噴射孔８ａから噴射されるジェットの強度を推定し、点火プラグ１７での点火時期を制御する。 Further, the internal combustion engine control device 20 estimates the intensity of the jet injected from the sub-chamber injection hole 8a of the sub-chamber 8 based on the output signals from various sensors, and controls the ignition timing at the spark plug 17.
１－３．内燃機関制御装置２０におけるジェット強度の推定処理の構成例
　次に、図４を参照して内燃機関制御装置２０におけるジェット強度の推定処理の構成例について説明する。
　図４は、内燃機関制御装置２０におけるジェット強度の推定処理の構成を示すブロック図である。 1-3. Configuration Example of Jet Intensity Estimating Process in Internal Combustion Engine Control Device 20 Next, a configuration example of jet intensity estimation processing in the internal combustion engine control device 20 will be described with reference to FIG.
FIG. 4 is a block diagram showing a configuration of jet intensity estimation processing in the internal combustion engine control device 20.
　図４に示すように、内燃機関制御装置２０は、ノックセンサ信号取得部１０１と、バンド幅・閾値取得部１０２と、クランク角情報取得部１０３と、回転変動取得部１０４と、着火時刻推定部１０５と、クランク軸加速開始時刻推定部１０６とを有している。さらに、内燃機関制御装置２０は、ジェット強度推定部１０７と、ジェット強度比較部１０８と、点火時期出力部１０９と、ジェット強度上限値・下限値計算部１１０とを有している。 As shown in FIG. 4, the internal combustion engine control device 20 includes a knock sensor signal acquisition unit 101, a bandwidth / threshold acquisition unit 102, a crank angle information acquisition unit 103, a rotation fluctuation acquisition unit 104, and an ignition time estimation unit. It has 105 and a crank shaft acceleration start time estimation unit 106. Further, the internal combustion engine control device 20 includes a jet intensity estimation unit 107, a jet intensity comparison unit 108, an ignition timing output unit 109, and a jet intensity upper limit value / lower limit value calculation unit 110.
　ノックセンサ信号取得部１０１は、ノックセンサ４７に接続されており、ノックセンサ４７からのノックセンサ信号、シリンダ１４の振動情報、すなわち加速度情報を取得する。ノックセンサ信号取得部１０１は、着火時刻推定部１０５に接続されており、取得したノックセンサ信号を着火時刻推定部１０５に出力する。 The knock sensor signal acquisition unit 101 is connected to the knock sensor 47 and acquires the knock sensor signal from the knock sensor 47 and the vibration information of the cylinder 14, that is, the acceleration information. The knock sensor signal acquisition unit 101 is connected to the ignition time estimation unit 105, and outputs the acquired knock sensor signal to the ignition time estimation unit 105.
　バンド幅・閾値取得部１０２は、エンジンの回転数情報や、エンジンの形状情報等が入力される。エンジンの形状情報は、エンジンに搭載されたシリンダ１４の数、すなわち気筒数である。バンド幅・閾値取得部１０２は、着火時刻推定部１０５において、ノックセンサ信号に対してフィルタ処理を行う際のバンド幅の設定値や、着火時刻の推定処理に用いる閾値を、エンジンの回転数情報やエンジンの形状情報等に基づいて取得する。バンド幅・閾値取得部１０２は、取得したバンド幅と閾値を着火時刻推定部１０５に出力する。 Bandwidth / threshold value acquisition unit 102 is input with engine speed information, engine shape information, and the like. The shape information of the engine is the number of cylinders 14 mounted on the engine, that is, the number of cylinders. The bandwidth / threshold acquisition unit 102 sets the bandwidth set value when filtering the knock sensor signal in the ignition time estimation unit 105, and the threshold used for the ignition time estimation process is used for engine speed information. And the shape information of the engine. The bandwidth / threshold value acquisition unit 102 outputs the acquired bandwidth and threshold value to the ignition time estimation unit 105.
　バンド幅・閾値取得部１０２は、エンジンの固有振動数や回転による機械振動が含まれないようにバンド幅の低周波側を設定する。すなわち、エンジンの回転数が高くなるほど、固有振動数も高くなるため、バンド幅の下限値は大きく設定される。また、固有振動数は、エンジンの気筒数、すなわち４気筒エンジンか３気筒エンジンによって変化する。そのため、バンド幅・閾値取得部１０２は、制御対象となるエンジンの気筒数に基づいて、バンド幅の設定値の中に固有振動数が含まれないように、バンド幅の下限値を変更する。 The bandwidth / threshold value acquisition unit 102 sets the low frequency side of the bandwidth so that the natural frequency of the engine and the mechanical vibration due to rotation are not included. That is, the higher the engine speed, the higher the natural frequency, so the lower limit of the bandwidth is set larger. The natural frequency varies depending on the number of cylinders of the engine, that is, a 4-cylinder engine or a 3-cylinder engine. Therefore, the bandwidth / threshold value acquisition unit 102 changes the lower limit of the bandwidth based on the number of cylinders of the engine to be controlled so that the natural frequency is not included in the set value of the bandwidth.
　また、エンジンの回転数が低くなるほど、またはエンジンの負荷が小さくなるほど、機械振動の振幅は、小さくなる。そのため、バンド幅・閾値取得部１０２は、エンジンの回転数やエンジンの負荷が小さくなるほど、閾値を小さくなるように設定する。 Also, the lower the engine speed or the smaller the engine load, the smaller the amplitude of mechanical vibration. Therefore, the bandwidth / threshold value acquisition unit 102 is set so that the threshold value becomes smaller as the engine speed and the engine load become smaller.
　着火時刻推定部１０５は、バンド幅・閾値取得部１０２から出力されたバンド幅に基づいて、ノックセンサ信号取得部１０１から出力されたノックセンサ信号に対してフィルタ処理を行い、燃焼成分を抽出する。さらに、着火時刻推定部１０５は、抽出した燃焼成分と、バンド幅・閾値取得部１０２から出力された閾値に基づいて、ジェットによる着火時刻（ジェット開始時刻ｔｊｅｔ）を推定する。そして、着火時刻推定部１０５は、推定した着火時刻をクランク軸加速開始時刻推定部１０６に出力する。 The ignition time estimation unit 105 filters the knock sensor signal output from the knock sensor signal acquisition unit 101 based on the bandwidth output from the bandwidth / threshold value acquisition unit 102, and extracts the combustion component. .. Further, the ignition time estimation unit 105 estimates the ignition time by the jet (jet start time t jet ) based on the extracted combustion component and the threshold value output from the bandwidth / threshold value acquisition unit 102. Then, the ignition time estimation unit 105 outputs the estimated ignition time to the crank shaft acceleration start time estimation unit 106.
　着火時刻補正部を示すクランク軸加速開始時刻推定部１０６は、着火時刻推定部１０５から出力された着火時刻と、予め記憶しているピストン機構に起因する時間遅れに基づいて、クランク軸４８の加速が開始される時刻、すなわちクランク軸加速開始タイミングｔａｃｃを推定する。すなわち、ランク軸加速開始時刻推定部１０６は、ピストン機構に起因する時間遅れに基づいて、着火時刻を補正する。そして、クランク軸加速開始時刻推定部１０６は、推定したクランク軸加速開始タイミングをジェット強度推定部１０７に出力する。 The crank shaft acceleration start time estimation unit 106 indicating the ignition time correction unit accelerates the crank shaft 48 based on the ignition time output from the ignition time estimation unit 105 and the time delay caused by the piston mechanism stored in advance. Is estimated, that is, the crank shaft acceleration start timing t acc is estimated. That is, the rank axis acceleration start time estimation unit 106 corrects the ignition time based on the time delay caused by the piston mechanism. Then, the crank shaft acceleration start time estimation unit 106 outputs the estimated crank shaft acceleration start timing to the jet intensity estimation unit 107.
　クランク角情報取得部１０３は、クランク角センサ４９に接続されており、クランク角センサ４９からクランク角情報を取得する。そして、クランク角情報取得部１０３は、取得したクランク角情報を、回転変動取得部１０４に出力する。 The crank angle information acquisition unit 103 is connected to the crank angle sensor 49, and acquires crank angle information from the crank angle sensor 49. Then, the crank angle information acquisition unit 103 outputs the acquired crank angle information to the rotation fluctuation acquisition unit 104.
　回転変動取得部１０４は、クランク角情報に基づいて、着火時刻より後に発生する回転変化量を取得（計算）する。なお、回転変動取得部１０４は、クランク軸４８に設けた歯と歯の間隔毎の回転数の変化量を取得する。また、回転変動取得部１０４は、取得した回転数変化量をジェット強度推定部１０７に出力する。 The rotation fluctuation acquisition unit 104 acquires (calculates) the amount of rotation change that occurs after the ignition time based on the crank angle information. The rotation fluctuation acquisition unit 104 acquires the amount of change in the rotation speed for each distance between the teeth provided on the crank shaft 48. Further, the rotation fluctuation acquisition unit 104 outputs the acquired rotation speed change amount to the jet intensity estimation unit 107.
　ジェット強度推定部１０７は、クランク軸加速開始タイミングと、回転数の変動量に基づいて、ジェット強度を推定する。そして、ジェット強度推定部１０７は、推定したジェット強度をジェット強度比較部１０８に出力する。 The jet strength estimation unit 107 estimates the jet strength based on the crank shaft acceleration start timing and the fluctuation amount of the rotation speed. Then, the jet intensity estimation unit 107 outputs the estimated jet intensity to the jet intensity comparison unit 108.
　ジェット強度比較部１０８には、ジェット強度推定部１０７が推定したジェット強度だけでなく、ジェット強度上限値・下限値計算部１１０が計算した上限値と下限値が出力される。ジェット強度比較部１０８は、ジェット強度推定部１０７が推定したジェット強度と、ジェット強度上限値・下限値計算部１１０が計算した上限値及び下限値と比較する。そして、ジェット強度比較部１０８は、比較した結果を、点火時期出力部１０９に出力する。点火時期出力部１０９は、ジェット強度比較部１０８が比較した結果に基づいて、点火時期を制御する。 Not only the jet intensity estimated by the jet intensity estimation unit 107 but also the upper limit value and the lower limit value calculated by the jet intensity upper limit value / lower limit value calculation unit 110 are output to the jet intensity comparison unit 108. The jet intensity comparison unit 108 compares the jet intensity estimated by the jet intensity estimation unit 107 with the upper limit value and the lower limit value calculated by the jet intensity upper limit value / lower limit value calculation unit 110. Then, the jet intensity comparison unit 108 outputs the comparison result to the ignition timing output unit 109. The ignition timing output unit 109 controls the ignition timing based on the result of comparison by the jet intensity comparison unit 108.
　なお、各処理部の詳細な処理方法については、後述する。 The detailed processing method of each processing unit will be described later.
１－４．ジェット強度の実例と、ジェット強度の違いによる燃料消費量及び熱損失量
　次に、図５Ａから図５Ｃを参照して、ジェット強度の実例と、ジェット強度の違いによる燃料消費量及び熱損失量について説明する。
　図５Ａは、ジェット強度の違いによる副室８の圧力と主燃焼室１４ａの圧力との差（圧力差）を示すもので、縦軸に圧力差［ＭＰａ］、横軸にクランク角度を示している。図５Ｂは、ジェット強度の違いと燃焼消費率の関係を示す図、図５Ｃはジェット強度の違いと主燃焼室１４ａの壁面への熱損失量の関係を示す図である。図５Ｂにおける縦軸は熱消費率ＩＳＦＣ［ｇ／ｋＷｈ］を示す、図５Ｃにおける縦軸は熱損失量［Ｗ］を示している。そして、図５Ｂ及び図５Ｃにおける横軸はジェット強度を示している。 1-4. Example of jet strength and fuel consumption and heat loss due to difference in jet strength Next, referring to FIGS. 5A to 5C, an example of jet strength and fuel consumption and heat loss due to difference in jet strength explain.
FIG. 5A shows the difference (pressure difference) between the pressure in the sub chamber 8 and the pressure in the main combustion chamber 14a due to the difference in jet strength. The vertical axis shows the pressure difference [MPa] and the horizontal axis shows the crank angle. There is. FIG. 5B is a diagram showing the relationship between the difference in jet intensity and the combustion consumption rate, and FIG. 5C is a diagram showing the relationship between the difference in jet intensity and the amount of heat loss to the wall surface of the main combustion chamber 14a. The vertical axis in FIG. 5B shows the heat consumption rate ISFC [g / kWh], and the vertical axis in FIG. 5C shows the heat loss amount [W]. The horizontal axis in FIGS. 5B and 5C indicates the jet intensity.
　図５Ａに示すように、副室噴射孔８ａが副室８から主燃焼室１４ａに噴出する際に圧力差は最大値となる。そして、この圧力差の最大値をジェット強度と定義する。また、副室８から噴出するジェット強度が高いほど、混合気への着火が安定する。しかしながら、ジェット強度が高い場合、図５Ｃに示すように、副室８や主燃焼室１４ａの壁面への熱損失が増加する。その結果、図５Ｂに示すように、燃料消費率（燃料消費量）が増大し、副燃焼室による燃費低減効果が減少するおそれがある。 As shown in FIG. 5A, the pressure difference becomes the maximum value when the sub chamber injection hole 8a ejects from the sub chamber 8 to the main combustion chamber 14a. Then, the maximum value of this pressure difference is defined as the jet intensity. Further, the higher the jet intensity ejected from the sub chamber 8, the more stable the ignition of the air-fuel mixture is. However, when the jet strength is high, as shown in FIG. 5C, the heat loss to the wall surface of the sub chamber 8 and the main combustion chamber 14a increases. As a result, as shown in FIG. 5B, the fuel consumption rate (fuel consumption) may increase, and the fuel consumption reduction effect of the sub-combustion chamber may decrease.
　また、ジェット強度が更に増加すると、ジェット噴出によって主燃焼室１４ａの圧力変動が増大し、ノッキングを誘発してしまうおそれがある。そのため、ジェット強度は、燃焼安定性と熱損失のバランスを取りながら、適切な範囲に調整することが必要となる。 Further, if the jet strength is further increased, the pressure fluctuation of the main combustion chamber 14a increases due to the jet ejection, which may induce knocking. Therefore, it is necessary to adjust the jet strength to an appropriate range while balancing combustion stability and heat loss.
１－５．燃焼１サイクル当たりの圧力、回転数及び振動（加速度）の変化
　次に、燃焼１サイクル当たりの副室及び主燃焼室の圧力、圧力差、回転数及び振動（加速度）の変化について図６を参照して説明する。図６（ａ）は副室８の圧力、図６（ｂ）は主燃焼室１４ａの圧力、図６（ｃ）は圧力差、図６（ｄ）は回転数、図６（ｅ）は加速度、すなわちノックセンサの出力値を示している。なお、図６（ａ）及び図６（ｂ）に示すデータは、測定した波形を直接プロットしている。そして、図６（ｃ）に示すデータは、図６（ａ）及び図６（ｂ）に示すデータの差分をとったデータに対して、フィルタ処理を行い、ノイズ軽減処理を行ったデータである。 1-5. Changes in pressure, rotation speed and vibration (acceleration) per combustion cycle Next, see FIG. 6 for changes in pressure, pressure difference, rotation speed and vibration (acceleration) in the auxiliary chamber and main combustion chamber per combustion cycle. I will explain. 6 (a) shows the pressure in the sub chamber 8, FIG. 6 (b) shows the pressure in the main combustion chamber 14a, FIG. 6 (c) shows the pressure difference, FIG. 6 (d) shows the number of revolutions, and FIG. 6 (e) shows the acceleration. That is, the output value of the knock sensor is shown. The data shown in FIGS. 6 (a) and 6 (b) directly plot the measured waveforms. The data shown in FIG. 6 (c) is data obtained by filtering the data obtained by taking the difference between the data shown in FIGS. 6 (a) and 6 (b) and performing noise reduction processing. ..
　図６（ａ）に示すように、副室８の圧力は、上死点において１度目のピークを迎える。その後、燃焼により圧力が再上昇し、２度目のピークを迎える。そして、図６（ｂ）に示すように、主燃焼室１４ａの圧力の挙動も、副室８の圧力の挙動とほぼ同じになる。しかしながら、図６（ａ）及び図６（ｂ）に示すように、両者の間には、若干の位相差が発生する。そのため、副室８の圧力が燃焼により上昇し始めた直後に、図６（ｃ）に示すように、副室８と主燃焼室１４ａの圧力差は、ピークを迎える。この圧力差のピークを迎えた瞬間が、ジェットが副室８から主燃焼室１４ａに噴射されるタイミングであり、ジェットの開始時期とみなされる。 As shown in FIG. 6A, the pressure in the sub-chamber 8 reaches its first peak at top dead center. After that, the pressure rises again due to combustion and reaches the second peak. Then, as shown in FIG. 6B, the pressure behavior of the main combustion chamber 14a is almost the same as the pressure behavior of the sub chamber 8. However, as shown in FIGS. 6 (a) and 6 (b), a slight phase difference occurs between the two. Therefore, immediately after the pressure in the sub chamber 8 starts to rise due to combustion, the pressure difference between the sub chamber 8 and the main combustion chamber 14a reaches a peak as shown in FIG. 6 (c). The moment when the peak of this pressure difference is reached is the timing at which the jet is injected from the sub chamber 8 into the main combustion chamber 14a, and is regarded as the start time of the jet.
　図６（ｄ）は、クランク角センサ４９が検出した信号に基づいて、エンジンの回転数を算出した図である。本例では、上述したうように、クランク角の検出間隔が６ｄｅｇのクランク角センサ４９を用いている。すなわち、クランク角センサ４９は、クランク角６ｄｅｇおきに、クランク軸４８に設けた歯を検出する。そして、クランク角情報取得部１０３は、１つの前の歯を検出した時間からの時間差を検出し、その時間差に基づいてクランク軸４８が６ｄｅｇ進むのにかかった時間を求め、この時間からエンジンの回転数を算出している。 FIG. 6D is a diagram in which the engine speed is calculated based on the signal detected by the crank angle sensor 49. In this example, as described above, the crank angle sensor 49 having a crank angle detection interval of 6 deg is used. That is, the crank angle sensor 49 detects the teeth provided on the crank shaft 48 at every 6 deg crank angle. Then, the crank angle information acquisition unit 103 detects a time difference from the time when one previous tooth is detected, obtains the time required for the crank shaft 48 to advance 6 deg based on the time difference, and obtains the time required for the crank shaft 48 to advance by 6 deg from this time. The number of rotations is calculated.
　図６（ｄ）に示すように、エンジンの回転数は、燃焼１サイクルの中で数十ｒｐｍ常時変動している。圧縮行程では、負のトルクが発生するため、回転速度は低下する。また、膨張行程において燃焼が発生すると、燃焼圧によりピストン１８が押圧されるため、上死点３６０ｄｅｇ．ＡＴＤＣ後から膨張行程中盤の４５０ｄｅｇ．ＡＴＤＣにかけて、回転数の増加が発生する。 As shown in FIG. 6D, the engine speed constantly fluctuates by several tens of rpm in one combustion cycle. In the compression stroke, a negative torque is generated, so that the rotation speed decreases. Further, when combustion occurs in the expansion stroke, the piston 18 is pressed by the combustion pressure, so that the top dead center is 360 deg. 450 deg. From after ATDC to the middle of the expansion process. The number of revolutions increases toward ATDC.
　また、図６（ｅ）に示すように、ジェットの開始時期には、振動波形の周波数に変化が見られるが、燃焼時期以外にも多々振動が発生している場面が見られる。これは、主にエンジン側の負荷変動や、バルブ開閉時の機械振動であると考えられる。そのため、適切なフィルタ処理を行うことで、これらの影響を除去することができる。 Further, as shown in FIG. 6 (e), the frequency of the vibration waveform is changed at the start time of the jet, but there are many scenes where vibration is generated other than the combustion time. It is considered that this is mainly the load fluctuation on the engine side and the mechanical vibration when opening and closing the valve. Therefore, these effects can be eliminated by performing appropriate filtering.
　ここで、エンジンの回転数と主燃焼室１４ａの圧力の関係について説明する。クランク角センサ４９により、角速度ω得られた場合、燃焼時に生じるトルク、すなわち燃焼トルクτｃｏｍｂは、摩擦トルクτｆｒｉｃ、慣性トルクτｉｎｎｅｒ、負荷トルクτｌｏａｄ及びエンジン回転系の慣性Ｊから下記数１で表される。 Here, the relationship between the engine speed and the pressure in the main combustion chamber 14a will be described. When the angular velocity ω is obtained by the crank angle sensor 49, the torque generated during combustion, that is, the combustion torque τ comb , is the following number 1 from the friction torque τ fric , the inertia torque τ inner , the load torque τ load , and the inertia J of the engine rotation system. It is represented by.
Figure JPOXMLDOC01-appb-M000001
Figure JPOXMLDOC01-appb-M000001
　数１に示すように、燃焼トルクτｃｏｍｂを求めるには、角速度ωの微分値ｄωを計算する必要がある。しかしながら、クランク角センサ４９により測定される角速度ωには、様々なノイズが含まれている。そのため、通常の微分を行うと、このノイズが強調され、正確なトルク波形を再現することができない。したがって、微分によるノイズの強調を避けるために、角速度ωに含まれる高周波成分をカットした結果を用いて燃焼トルクτｃｏｍｂを推定してもよい。以下、角速度ωの微分値ｄωを、回転数変化率と称す。 As shown in Equation 1, in order to obtain the combustion torque τ comb , it is necessary to calculate the differential value dω of the angular velocity ω. However, the angular velocity ω measured by the crank angle sensor 49 contains various noises. Therefore, when normal differentiation is performed, this noise is emphasized and an accurate torque waveform cannot be reproduced. Therefore, in order to avoid the emphasis of noise due to differentiation, the combustion torque τ comb may be estimated using the result of cutting the high frequency component included in the angular velocity ω. Hereinafter, the differential value dω of the angular velocity ω is referred to as a rotation speed change rate.
　また、推定された燃焼τｃｏｍｂには、摩擦トルクτｆｒｉｃや負荷トルクτｌｏａｄによるオフセットが含まれている。そのため、事前適合により、このオフセット量を推定して補正する。または、４気筒エンジンのコネクティングロッドの幾何学的な特徴を用いて、このオフセットを打ち消し、補正後の推定トルクτｃｏｍｐｅｎｓａｔｉｏｎを得ることができる。この補正後の推定トルクτｃｏｍｐｅｎｓａｔｉｏｎと、エンジンの回転数、すなわち角速度ωの関係は、下記数２となる。 Further, the estimated combustion τ comb includes an offset due to the friction torque τ fric and the load torque τ load . Therefore, this offset amount is estimated and corrected by pre-adaptation. Alternatively, the geometric features of the connecting rod of the 4-cylinder engine can be used to cancel this offset and obtain the corrected estimated torque τ compression . The relationship between the estimated torque τ compression after this correction and the engine speed, that is, the angular velocity ω is the following equation 2.
Figure JPOXMLDOC01-appb-M000002
Figure JPOXMLDOC01-appb-M000002
　次に、得られた推定トルクτｃｏｍｐｅｎｓａｔｉｏｎから主燃焼室１４ａ内の圧力、すなわち筒内圧Ｐｃｏｍｂを算出する。推定トルクτｃｏｍｐｅｎｓａｔｉｏｎと、筒内圧Ｐｃｏｍｂの関係は、ピストン機構学的に定まるため、下記数３で表される。ここで、Ａｃｙｌは、主燃焼室１４ａの断面積、Ｒはクランクアームの長さ、φは、クランクアームと中心軸の間の角度を示す。 Next, the pressure in the main combustion chamber 14a, that is, the in-cylinder pressure Pcomb is calculated from the obtained estimated torque τcompression . The relationship between the estimated torque τ compression and the in-cylinder pressure P comb is determined by the piston mechanism, and is therefore represented by the following equation 3. Here, A coil indicates the cross-sectional area of the main combustion chamber 14a, R indicates the length of the crank arm, and φ indicates the angle between the crank arm and the central axis.
Figure JPOXMLDOC01-appb-M000003
Figure JPOXMLDOC01-appb-M000003
　そして、上記数２と数３を合わせることで、回転数変化率ｄωと、主燃焼室１４ａの筒内圧Ｐｃｏｍｂの関係は、以下の数４で表される。 Then, by combining the above equations 2 and 3, the relationship between the rotation speed change rate dω and the in-cylinder pressure Pcomb of the main combustion chamber 14a is represented by the following equation 4.
Figure JPOXMLDOC01-appb-M000004
Figure JPOXMLDOC01-appb-M000004
　図６（ｄ）に示すように、ジェット発生直後の３７０ｄｅｇＡＴＤＣ付近に、エンジンの回転数がクランク角度の歯１区間（すなわち、６ｄｅｇ）の間で急上昇している区間が見られる。この回転数の上昇は、副燃焼室にて毎サイクル、特定の区間にて発生することが確認されている。そして、この回転数の上昇は、ジェット点火による急速な主燃焼室１４ａの圧力の上昇ｄＰ／ｄθによりもたらされたものであると考えられる。そのため、回転数変化率ｄωを推定することで、主燃焼室１４ａの圧力の上昇ｄＰ／ｄθを求めることができ、ジェット強度も推定することができる。 As shown in FIG. 6 (d), in the vicinity of 370 deg ATDC immediately after the jet is generated, a section in which the engine speed rapidly rises between one tooth section (that is, 6 deg) of the crank angle can be seen. It has been confirmed that this increase in the number of revolutions occurs in a specific section every cycle in the auxiliary combustion chamber. It is considered that this increase in the number of revolutions is caused by a rapid increase in the pressure of the main combustion chamber 14a due to jet ignition, dP / dθ. Therefore, by estimating the rotation speed change rate dω, the pressure rise dP / dθ of the main combustion chamber 14a can be obtained, and the jet intensity can also be estimated.
１－６．回転数変化率の推定方法
　次に、図７を算出して従来の回転数変化率ｄωの推定方法と、本例の回転数変化率ｄωの推定方法について説明する。
　図７は、回転数変化率ｄωの推定方法を示すイメージ図である。図７における横軸は時刻、縦軸はエンジンの回転数（角速度ω）を示している。そして、図７に示す黒丸は、クランク角センサ４９の検出信号を（クランク角センサ信号）示している。そして、クラン角センサ信号は、歯の間隔ごとに出力値が更新される離散値である。そのため、歯と歯の間におけるエンジンの回転数は、その前後区間におけるエンジンの回転数を線形補間して算出されるため、図７に示す実線Ａ１、Ａ２のような折れ線グラフとなる。そして、実線Ａ１は、本例の推定方法を示し、実線Ａ２は従来の推定方法を示している。また、図７に示す点線は、実際の回転数挙動を示している。 1-6. Method for Estimating Rotational Speed Change Rate Next, FIG. 7 will be calculated to explain the conventional method for estimating the rotational speed change rate dω and the method for estimating the rotational speed change rate dω in this example.
FIG. 7 is an image diagram showing a method of estimating the rotation speed change rate dω. In FIG. 7, the horizontal axis represents the time and the vertical axis represents the engine speed (angular velocity ω). The black circles shown in FIG. 7 indicate the detection signal of the crank angle sensor 49 (crank angle sensor signal). The clan angle sensor signal is a discrete value whose output value is updated for each tooth spacing. Therefore, the engine speed between the teeth is calculated by linearly interpolating the engine speed in the front and rear sections thereof, so that the line graph is as shown in the solid lines A1 and A2 shown in FIG. The solid line A1 shows the estimation method of this example, and the solid line A2 shows the conventional estimation method. The dotted line shown in FIG. 7 shows the actual rotation speed behavior.
　また、点火時期後にジェットにより加速が発生する区間（ｔｘ+１－ｔｘ）における回転数変化量Δωは、回転変動取得部１０４により下記数５に基づいて算出される。 Further, the rotation speed change amount Δω in the section (t x + 1 −t x ) where acceleration is generated by the jet after the ignition timing is calculated by the rotation speed fluctuation acquisition unit 104 based on the following equation 5.
Figure JPOXMLDOC01-appb-M000005
Figure JPOXMLDOC01-appb-M000005
　まず、従来の回転数変化率ｄωの推定方法について説明する。従来の推定方法では、クランク角センサ４９の信号のみを用いて回転数変化率ｄωを算出している。すなわち、回転数変化率ｄωは、下記数６に示すように、回転数変化量Δωを区間の長さである（ｔｘ+１－ｔｘ）を割ることで算出される。 First, a conventional method for estimating the rotation speed change rate dω will be described. In the conventional estimation method, the rotation speed change rate dω is calculated using only the signal of the crank angle sensor 49. That is, the rotation speed change rate dω is calculated by dividing the rotation speed change amount Δω by the length of the section (t x + 1 −t x ), as shown in Equation 6 below.
Figure JPOXMLDOC01-appb-M000006
Figure JPOXMLDOC01-appb-M000006
　ここで、数６により算出される回転数変化率ｄωは、クランク角６ｄｅｇの区間における平均回転速度の変化を表すことになり、図７に示す実線Ａ２の傾きに相当する。しかしながら、短時間で発生するジェットに起因する回転数の変化を捉えようとした場合、その影響が平滑化され、十分な推定精度を得ることができない。 Here, the rotation speed change rate dω calculated by Equation 6 represents the change in the average rotation speed in the section of the crank angle of 6 deg, and corresponds to the slope of the solid line A2 shown in FIG. However, when trying to capture the change in the number of revolutions caused by the jet generated in a short time, the influence is smoothed and sufficient estimation accuracy cannot be obtained.
　次に、本例の回転数変化率ｄωの推定方法について説明する。本例の内燃機関制御装置２０では、加速度センサであるノックセンサ４７の信号と、クランク角センサ４９のクランク角信号を用いて回転数変化率ｄωを算出している。まず、ノックセンサ信号取得部１０１により、図６（ｅ）に示すノックセンサ４７の信号を取得する。そして、着火時刻推定部１０５により、ノックセンサ信号取得部１０１が取得したノックセンサの信号を処理する。 Next, the method of estimating the rotation speed change rate dω of this example will be described. In the internal combustion engine control device 20 of this example, the rotation speed change rate dω is calculated using the signal of the knock sensor 47, which is an acceleration sensor, and the crank angle signal of the crank angle sensor 49. First, the knock sensor signal acquisition unit 101 acquires the signal of the knock sensor 47 shown in FIG. 6 (e). Then, the ignition time estimation unit 105 processes the knock sensor signal acquired by the knock sensor signal acquisition unit 101.
　ここで、図８（ａ）から図８（ｃ）を参照してノックセンサ信号の信号処理について説明する。
　図８（ａ）は、ノックセンサ４７の出力値（ノックセンサ信号）を示す波形であり、図８（ｂ）はノックセンサ信号に対してフィルタ処理を行ったフィルタ出力値を示す波形である。図８（ｃ）は、フィルタ出力値の絶対値を示す図である。 Here, signal processing of the knock sensor signal will be described with reference to FIGS. 8 (a) to 8 (c).
FIG. 8A is a waveform showing an output value (knock sensor signal) of the knock sensor 47, and FIG. 8B is a waveform showing a filter output value obtained by filtering the knock sensor signal. FIG. 8C is a diagram showing an absolute value of the filter output value.
　図８（ａ）に示すノックセンサ信号に対して着火時刻推定部１０５がフィルタ処理を行うことで、図８（ｂ）に示すフィルタ出力値を得ることができる。すなわち、着火時刻推定部１０５は、ノックセンサ信号に対して、フィルタ処理を行うことで、燃焼に起因する振動成分を抽出する。なお、着火時刻推定部１０５は、フィルタ処理として、バンド幅・閾値取得部１０２から出力されたバンド幅を用いてノックセンサ信号に対してバンドパスフィルタを行う。 The ignition time estimation unit 105 filters the knock sensor signal shown in FIG. 8A to obtain the filter output value shown in FIG. 8B. That is, the ignition time estimation unit 105 extracts the vibration component caused by combustion by filtering the knock sensor signal. The ignition time estimation unit 105 performs a bandpass filter on the knock sensor signal using the bandwidth output from the bandwidth / threshold value acquisition unit 102 as a filter process.
　図８（ｂ）に示す例では、バンドパスフィルタのバンド領域として、１．０ｋＨｚから２．０ｋＨｚとした。バンド領域が１．０ｋＨｚよりも小さい領域をバンド領域に含めた場合、機械振動などに起因する低周波成分がフィルタ出力値に乗ってしまい、燃焼による振動成分として不適切な結果となる。そのため、バンド領域の下限値を１．０ｋＨｚとしている。また、バンド領域として、２．０ｋＨｚよりも大きい領域をバンド領域に含めた場合、燃焼開始前から高周波成分がフィルタ出力値に現れるようになり、こちらも燃焼に起因する振動成分を抽出するには不適切な波形となる。そのため、バンド領域の上限値を２．０ｋＨｚとしている。 In the example shown in FIG. 8B, the band region of the bandpass filter was set to 1.0 kHz to 2.0 kHz. When a region in which the band region is smaller than 1.0 kHz is included in the band region, a low frequency component caused by mechanical vibration or the like gets on the filter output value, resulting in an inappropriate result as a vibration component due to combustion. Therefore, the lower limit of the band region is set to 1.0 kHz. In addition, when a region larger than 2.0 kHz is included in the band region as the band region, high-frequency components will appear in the filter output value even before the start of combustion, and this is also a method for extracting vibration components caused by combustion. The waveform will be inappropriate. Therefore, the upper limit of the band region is set to 2.0 kHz.
　なお、バンド領域、すなわちバンド幅は、上述した１．０ｋＨｚから２．０ｋＨｚに限定されるものではなく、上述したように、バンド幅・閾値取得部１０２によりエンジンの回転数情報やエンジンの形状情報等に基づいて適宜設定される。 The bandwidth, that is, the bandwidth is not limited to the above-mentioned 1.0 kHz to 2.0 kHz, and as described above, the bandwidth / threshold value acquisition unit 102 provides engine speed information and engine shape information. It is set appropriately based on the above.
　また、着火時刻推定部１０５は、図８（ｂ）に示すフィルタ出力値を絶対値に変換し、図８（ｃ）に示す波形、すなわち振動の振幅を得る。そして、着火時刻推定部１０５は、振動の振幅が、バンド幅・閾値取得部１０２から出力された閾値を上回ったタイミングをジェットの開始タイミングとして判定し、ジェット開始時刻ｔｊｅｔを得る。 Further, the ignition time estimation unit 105 converts the filter output value shown in FIG. 8B into an absolute value, and obtains the waveform shown in FIG. 8C, that is, the amplitude of vibration. Then, the ignition time estimation unit 105 determines the timing at which the vibration amplitude exceeds the threshold value output from the bandwidth / threshold value acquisition unit 102 as the jet start timing, and obtains the jet start time t jet .
　なお、閾値は、上述したように、バンド幅・閾値取得部１０２がエンジンの回転数に基づいて適宜設定される。 As described above, the threshold value is appropriately set by the bandwidth / threshold value acquisition unit 102 based on the engine speed.
　このように、ノックセンサ４７から出力されたノックセンサ信号に対してフィルタ処理を行うことで、機械振動や高周波ノイズを適切に除去することができる。その結果、ジェットによる着火タイミングを精度よく検出することができる。 In this way, by performing filter processing on the knock sensor signal output from the knock sensor 47, mechanical vibration and high frequency noise can be appropriately removed. As a result, the ignition timing by the jet can be detected accurately.
　次に、ジェット開始時刻ｔｊｅｔに基づいて、クランク軸加速開始時刻推定部１０６がクランク軸加速開始タイミングｔａｃｃを推定する。上述した数４に示すように、主燃焼室１４ａにおける圧力上昇から回転数の増加が発生するまでには、ピストン機構やクランク軸４８の慣性質量に起因する応答遅れがある。そのため、クランク軸加速開始時刻推定部１０６には、ジェットによる圧力増加開始タイミングを振った主燃焼室１４ａの筒内圧Ｐｃｏｍｂ（θ）のプロファイルが複数用意されている。また、それらのプロファイルに対する回転数変化率ｄω（θ）の応答を計算し、主燃焼室１４ａにおける圧力の上昇から回転数の増加が発生するまでの時間遅れΔｔ（θ）がテーブルとして、クランク軸加速開始時刻推定部１０６には、記憶されている。 Next, the crank shaft acceleration start time estimation unit 106 estimates the crank shaft acceleration start timing t acc based on the jet start time t jet . As shown in Equation 4 above, there is a response delay due to the inertial mass of the piston mechanism and the crank shaft 48 from the increase in pressure in the main combustion chamber 14a to the increase in rotation speed. Therefore, the crank shaft acceleration start time estimation unit 106 is provided with a plurality of profiles of the in-cylinder pressure Pcomb (θ) of the main combustion chamber 14a at which the pressure increase start timing by the jet is changed. Further, the response of the rotation speed change rate dω (θ) to those profiles is calculated, and the time delay Δt (θ) from the increase in pressure in the main combustion chamber 14a to the occurrence of the increase in rotation speed is used as a table for the crank shaft. It is stored in the acceleration start time estimation unit 106.
　そして、この時間遅れΔｔ（θ）と、ジェット開始時刻ｔｊｅｔからクランク軸加速開始タイミングｔａｃｃは、下記数７により算出される。 Then, from this time delay Δt (θ) and the jet start time t jet , the crank shaft acceleration start timing t acc is calculated by the following equation 7.
Figure JPOXMLDOC01-appb-M000007
Figure JPOXMLDOC01-appb-M000007
　このようにして、クランク軸加速開始時刻推定部１０６によりピストン機構に起因する応答遅れを補正することで、ノックセンサ信号に基づいて、ジェットによる着火時刻から実際のクランク軸４８の加速開始タイミングを精度よく検出することができる。 In this way, the crank shaft acceleration start time estimation unit 106 corrects the response delay caused by the piston mechanism, so that the actual acceleration start timing of the crank shaft 48 is accurate from the ignition time by the jet based on the knock sensor signal. It can be detected well.
　次に、ジェット強度推定部１０７は、クランク軸４８の加速開始タイミングを起点に、クランク角センサ４９で検出される回転数を用いて、回転数変化率ｄωを算出する。すなわち、ジェット強度推定部１０７は、上述した数５で算出された回転数変化量Δωと、数７で算出されたクランク軸加速開始タイミングｔａｃｃを用いて、数８に基づいて回転数変化率Δωを算出する。 Next, the jet intensity estimation unit 107 calculates the rotation speed change rate dω using the rotation speed detected by the crank angle sensor 49, starting from the acceleration start timing of the crank shaft 48. That is, the jet intensity estimation unit 107 uses the rotation speed change amount Δω calculated in the above-mentioned equation 5 and the crank shaft acceleration start timing tac calculated in the equation 7, and the rotation speed change rate based on the equation 8. Calculate Δω.
Figure JPOXMLDOC01-appb-M000008
Figure JPOXMLDOC01-appb-M000008
　ここで、数８で算出されたΔωは、図５に示す実線Ａ１の傾きに相当する。図５に示すように、本例の回転数変化率Δωの推定方法では、回転数変化率Δωの計算開始点がクランク角センサ４９の歯の検出時刻ｔｘからノックセンサ４７により推定されたクランク軸加速開始タイミングｔａｃｃに変更していることが分かる。また、図５に示すように、本例の推定方法で得られた実線Ａ１を、従来の推定方法で得られる実線Ａ２よりも、点線で示す実際の回転数挙動に近づけることができる。 Here, Δω calculated by Equation 8 corresponds to the slope of the solid line A1 shown in FIG. As shown in FIG. 5, in the method of estimating the rotation speed change rate Δω of this example, the calculation start point of the rotation speed change rate Δω is the crank shaft estimated by the knock sensor 47 from the detection time tx of the teeth of the crank angle sensor 49. It can be seen that the acceleration start timing is changed to tacc . Further, as shown in FIG. 5, the solid line A1 obtained by the estimation method of this example can be closer to the actual rotation speed behavior shown by the dotted line than the solid line A2 obtained by the conventional estimation method.
　従来の推定方法では、ジェットによる着火タイミングに関係なく、計算開始点が常に時刻ｔｘとして回転数変化率Δωが計算される。その結果、クランク角センサ４９が検出する歯の間隔より細かい時間分解能を得ることができない。これに対して、本例の推定方法では、クランク軸加速開始タイミングｔａｃｃを計算開始点として回転数変化率Δωを計算するため、エンジンの状態により変動するジェット開始タイミングを考慮した回転数変化率Δωを算出することができる。 In the conventional estimation method, the rotation speed change rate Δω is calculated with the calculation start point always set to the time tx regardless of the ignition timing by the jet. As a result, it is not possible to obtain a time resolution finer than the tooth spacing detected by the crank angle sensor 49. On the other hand, in the estimation method of this example, since the rotation speed change rate Δω is calculated with the crank shaft acceleration start timing tac as the calculation start point, the rotation speed change rate considering the jet start timing that fluctuates depending on the engine state. Δω can be calculated.
１－７．ジェット強度の推定方法
　次に、上述した回転数変化率Δωを用いたジェット強度の推定方法について説明する。　上述した数４により、ごく短い時間の間では、θの項は定数とみなされるため、主燃焼室１４ａの筒内圧Ｐｃｏｍｂと、回転数変化率Δωには、下記数９に示すような比例関係が成り立つ。なお、数９に示すτはトルクである。 1-7. Jet strength estimation method Next, a jet strength estimation method using the above-mentioned rotation speed change rate Δω will be described. According to the above-mentioned equation 4, since the term θ is regarded as a constant for a very short time, the in-cylinder pressure Pcomb of the main combustion chamber 14a and the rotation speed change rate Δω are proportional to each other as shown in the following equation 9. The relationship holds. Note that τ shown in Equation 9 is torque.
Figure JPOXMLDOC01-appb-M000009
Figure JPOXMLDOC01-appb-M000009
　また、内燃機関では、一般的に、ｄＰ／ｄθが大きく急峻な圧力上昇が見られる場合に、主燃焼室１４ａの筒内圧Ｐｃｏｍｂも増加する。そのため、ジェット強度I＿ｊｅｔは、間接的に回転数変化率Δωを用いて下記数１０に基づいて算出することができる。なお、Ｐｐｒｅは、副燃焼室の圧力である。 Further, in an internal combustion engine, generally, when dP / dθ is large and a steep pressure increase is observed, the in-cylinder pressure P comb of the main combustion chamber 14a also increases. Therefore, the jet intensity I_jet can be calculated indirectly based on the following equation tens using the rotation speed change rate Δω. In addition, P pre is the pressure of the auxiliary combustion chamber.
Figure JPOXMLDOC01-appb-M000010
Figure JPOXMLDOC01-appb-M000010
　このように、回転数変化率Δωを推定することで、ジェット強度I＿ｊｅｔを推定することができる。 In this way, the jet intensity I_jet can be estimated by estimating the rotation speed change rate Δω.
　次に、従来のジェット強度の推定結果と本例のジェット強度の推定結果の精度について図９を参照して説明する。
　図９は、従来のジェット強度の推定結果と本例のジェット強度の推定結果の精度を示すグラフである。図９に各グラフの横軸は、回転数変化率ｄωを示している。また、図９における各グラフの縦軸は、副燃焼室と主燃焼室１４ａの圧力差、すなわちジェット強度を示している。そして、圧力差の最大値を、点火時期を０ｄｅｇ．ＡＴＣ、３ｄｅｇ．ＡＴＣ、６ｄｅｇ．ＡＴＣと変化させて、連続する５サイクルを平均化してプロットしたものである。 Next, the accuracy of the conventional jet intensity estimation result and the jet intensity estimation result of this example will be described with reference to FIG.
FIG. 9 is a graph showing the accuracy of the conventional jet intensity estimation result and the jet intensity estimation result of this example. In FIG. 9, the horizontal axis of each graph shows the rotation speed change rate dω. The vertical axis of each graph in FIG. 9 shows the pressure difference between the sub-combustion chamber and the main combustion chamber 14a, that is, the jet intensity. Then, the maximum value of the pressure difference is set to 0 deg. ATC, 3deg. ATC, 6deg. It is a plot of averaging 5 consecutive cycles with ATC.
　図９に示すように、クランク角センサ４９のみを使用して回転数変化率ｄωを推定した従来の推定結果では、回転数変化率ｄωとジェット強度との相関係数が０．６８となっている。これに対して、クランク角センサ４９とノックセンサ４７を併用して回転数変化率ｄωを推定した本例の推定結果では、回転数変化率ｄωとジェット強度との相関係数が０．８７となっている。このように、本例のジェット強度の推定結果の精度は、クランク角センサ４９のみを使用した従来のジェット強度の推定結果の精度よりも向上していることが分かる。すなわち、ノックセンサ４７の情報を併用することで、回転数変化率ｄωの時間分解能を向上させることができ、副室の圧力を検出する圧力センサを用いることなくジェット強度を精度よく推定することができる。 As shown in FIG. 9, in the conventional estimation result in which the rotation speed change rate dω is estimated using only the crank angle sensor 49, the correlation coefficient between the rotation speed change rate dω and the jet intensity is 0.68. There is. On the other hand, in the estimation result of this example in which the rotation speed change rate dω is estimated by using the crank angle sensor 49 and the knock sensor 47 together, the correlation coefficient between the rotation speed change rate dω and the jet strength is 0.87. It has become. As described above, it can be seen that the accuracy of the jet strength estimation result of this example is higher than the accuracy of the conventional jet strength estimation result using only the crank angle sensor 49. That is, by using the information of the knock sensor 47 together, the time resolution of the rotation speed change rate dω can be improved, and the jet intensity can be estimated accurately without using the pressure sensor that detects the pressure in the sub chamber. can.
１－８．ジェット強度の補正制御動作例
　次に、上述した構成を有する内燃機関制御装置２０におけるジェット強度の補正制御の動作例を図１０から図１２を参照して説明する。
　図１０は、ジェット強度の補正制御動作を示すフローチャートである。 1-8. Example of Jet Strength Correction Control Operation Next, an operation example of jet strength correction control in the internal combustion engine control device 20 having the above configuration will be described with reference to FIGS. 10 to 12.
FIG. 10 is a flowchart showing a jet intensity correction control operation.
　図１０に示すように、まず、内燃機関制御装置２０は、エンジンの暖気が完了しているか否かを判断する（ステップＳ１１）。エンジンが冷機状態である場合、ジェット強度が大幅に低下し、主燃焼室１４ａ側の燃焼が不安定になるおそれがある。そのため、ステップＳ１１の処理において、エンジンの暖気が完了していないと判断した場合（ステップＳ１１のＮＯ判定）、内燃機関制御装置２０は、ジェット強度の補正処理は行わずに処理を終了する。 As shown in FIG. 10, first, the internal combustion engine control device 20 determines whether or not the warming up of the engine is completed (step S11). When the engine is in a cold state, the jet strength is significantly reduced, and the combustion on the main combustion chamber 14a side may become unstable. Therefore, when it is determined in the process of step S11 that the warming up of the engine is not completed (NO determination in step S11), the internal combustion engine control device 20 ends the process without performing the jet strength correction process.
　ステップＳ１１の処理において、エンジンの暖気が完了していると判断した場合（ステップＳ１１のＹＥＳ判定）、ノックセンサ信号取得部１０１は、ノックセンサ４７からノックセンサ情報を取得する（ステップＳ１２）。そして、ノックセンサ信号取得部１０１は、取得したノックセンサ情報（ノックセンサ信号）を着火時刻推定部１０５に出力する。 When it is determined in the process of step S11 that the warming up of the engine is completed (YES determination in step S11), the knock sensor signal acquisition unit 101 acquires knock sensor information from the knock sensor 47 (step S12). Then, the knock sensor signal acquisition unit 101 outputs the acquired knock sensor information (knock sensor signal) to the ignition time estimation unit 105.
　次に、着火時刻推定部１０５は、ノックセンサ信号に対してフィルタ処理を行い、燃焼成分を抽出する（ステップＳ１３）。ステップＳ１３の処理では、着火時刻推定部１０５は、バンド幅・閾値取得部１０２から出力されたバンド幅を用いてノックセンサ信号に対してバンドパスフィルタを行う。これにより、上述したように、図８（ａ）に示すノックセンサ信号から図８（ｂ）に示すフィルタ出力値を得ることができる。 Next, the ignition time estimation unit 105 filters the knock sensor signal and extracts the combustion component (step S13). In the process of step S13, the ignition time estimation unit 105 performs a bandpass filter on the knock sensor signal using the bandwidth output from the bandwidth / threshold value acquisition unit 102. As a result, as described above, the filter output value shown in FIG. 8B can be obtained from the knock sensor signal shown in FIG. 8A.
　次に、着火時刻推定部１０５は、燃焼成分を抽出したフィルタ出力値に基づいて、ジェットよる着火時刻ｔｊｅｔを推定する（ステップＳ１４）。すなわち、着火時刻推定部１０５は、上述したように、フィルタ出力値を値絶対値に変換し、図８（ｃ）に示す波形、すなわち振動の振幅を得る。そして、着火時刻推定部１０５は、バンド幅・閾値取得部１０２から出力された閾値を上回ったタイミングをジェットによる着火時刻ｔｊｅｔとして推定する。また、着火時刻推定部１０５は、推定したジェットによる着火時刻ｔｊｅｔをクランク軸加速開始時刻推定部１０６に出力する。 Next, the ignition time estimation unit 105 estimates the ignition time t jet by the jet based on the filter output value from which the combustion component is extracted (step S14). That is, the ignition time estimation unit 105 converts the filter output value into an absolute value as described above, and obtains the waveform shown in FIG. 8C, that is, the amplitude of vibration. Then, the ignition time estimation unit 105 estimates the timing when the threshold value output from the bandwidth / threshold value acquisition unit 102 is exceeded as the ignition time t jet by the jet. Further, the ignition time estimation unit 105 outputs the estimated ignition time t jet by the jet to the crank shaft acceleration start time estimation unit 106.
　次に、クランク角情報取得部１０３は、クランク角センサ４９からクランク角情報を取得する（ステップＳ１５）。そして、クランク角情報取得部１０３は、取得したクランク角情報を、回転変動取得部１０４に出力する。また、回転変動取得部１０４は、数５から回転数変化量Δωを算出し、算出した回転数変化量Δωをジェット強度推定部１０７に出力する。 Next, the crank angle information acquisition unit 103 acquires crank angle information from the crank angle sensor 49 (step S15). Then, the crank angle information acquisition unit 103 outputs the acquired crank angle information to the rotation fluctuation acquisition unit 104. Further, the rotation speed change acquisition unit 104 calculates the rotation speed change amount Δω from the equation 5, and outputs the calculated rotation speed change amount Δω to the jet intensity estimation unit 107.
　また、クランク軸加速開始時刻推定部１０６は、ジェット開始時刻ｔｊｅｔと数６に基づいて、クランク軸加速開始タイミング（時刻）ｔａｃｃを推定する（ステップ１６）。そして、クランク軸加速開始時刻推定部１０６は、推定したクランク軸加速開始時刻ｔａｃｃをジェット強度推定部１０７に出力する。 Further, the crank shaft acceleration start time estimation unit 106 estimates the crank shaft acceleration start timing (time) t acc based on the jet start time t jet and the equation 6 (step 16). Then, the crank shaft acceleration start time estimation unit 106 outputs the estimated crank shaft acceleration start time tac to the jet intensity estimation unit 107.
　次に、ジェット強度推定部１０７は、回転数変化量Δωと、クランク軸加速開始時刻ｔａｃｃに基づいて、加速開始時刻ｔａｃｃよりも後に発生する回転数変化率ｄωからジェット強度Ｉ＿ｊｅｔを推定する（ステップＳ１７）。すなわち、ジェット強度推定部１０７は、数８に基づいて、回転数変化率ｄωを算出し、この回転数変化率ｄωをジェット強度Ｉ＿ｊｅｔとして推定する。そして、ジェット強度推定部１０７は、推定したジェット強度Ｉ＿ｊｅｔをジェット強度比較部１０８に出力する。 Next, the jet intensity estimation unit 107 estimates the jet intensity I_jet from the rotation speed change rate dω that occurs after the acceleration start time tacc , based on the rotation speed change amount Δω and the crank shaft acceleration start time tacc. (Step S17). That is, the jet intensity estimation unit 107 calculates the rotation speed change rate dω based on the equation 8, and estimates the rotation speed change rate dω as the jet intensity I_jet. Then, the jet intensity estimation unit 107 outputs the estimated jet intensity I_jet to the jet intensity comparison unit 108.
　ジェット強度比較部１０８は、ジェット強度Ｉ＿ｊｅｔが、ジェット強度上限値・下限値計算部１１０から出力された下限値Ｉｍｉｎ以上であるか否かを判断する（ステップＳ１８）。ステップＳ１８の処理において、ジェット強度Ｉ＿ｊｅｔが下限値Ｉｍｉｎよりも小さいと判断した場合（ステップＳ１８のＮＯ判定）、内燃機関制御装置２０は、ジェット強度の増加処理を実施する（ステップＳ１９）。ステップＳ１９によるジェット強度の増加処理が完了すると、再びステップＳ１２の処理に戻る。 The jet intensity comparison unit 108 determines whether or not the jet intensity I_jet is equal to or greater than the lower limit value Imin output from the jet intensity upper limit value / lower limit value calculation unit 110 (step S18). When it is determined in the process of step S18 that the jet intensity I_jet is smaller than the lower limit value Imin (NO determination in step S18), the internal combustion engine control device 20 performs the jet intensity increase process (step S19). When the jet intensity increasing process in step S19 is completed, the process returns to step S12 again.
　また、ステップＳ１８の処理において、ジェット強度Ｉ＿ｊｅｔが下限値Ｉｍｉｎ以上であると判断した場合（ステップＳ１８のＹＥＳ判定）、ステップＳ２０の処理に移行する。ステップＳ２０の処理では、ジェット強度比較部１０８は、ジェット強度Ｉ＿ｊｅｔが、ジェット強度上限値・下限値計算部１１０から出力された上限値Ｉｍａｘ以上であるか否かを判断する。 Further, in the process of step S18, when it is determined that the jet intensity I_jet is equal to or higher than the lower limit value Imin (YES determination in step S18), the process proceeds to the process of step S20. In the process of step S20, the jet intensity comparison unit 108 determines whether or not the jet intensity I_jet is equal to or greater than the upper limit value Imax output from the jet intensity upper limit value / lower limit value calculation unit 110.
　ステップＳ２０の処理において、ジェット強度Ｉ＿ｊｅｔが上限値Ｉｍａｘよりも大きいと判断した場合（ステップＳ２０のＮＯ判定）、内燃機関制御装置２０は、ジェット強度の低減処理を実施する（ステップＳ２１）。ステップＳ２１によるジェット強度の増加処理が完了すると、再びステップＳ１２の処理に戻る。 In the process of step S20, when it is determined that the jet intensity I_jet is larger than the upper limit value Imax (NO determination in step S20), the internal combustion engine control device 20 executes the jet intensity reduction process (step S21). When the jet intensity increasing process in step S21 is completed, the process returns to step S12 again.
　ステップＳ２０の処理において、ジェット強度Ｉ＿ｊｅｔが上限値Ｉｍａｘ以下であると判断した場合（ステップＳ２０のＹＥＳ判定）、内燃機関制御装置２０は、ジェット強度Ｉ＿ｊｅｔが適切な範囲内に収まっていると判断し、制御を終了する。 When it is determined in the process of step S20 that the jet intensity I_jet is equal to or less than the upper limit value Imax (YES determination in step S20), the internal combustion engine control device 20 determines that the jet intensity I_jet is within an appropriate range. , End control.
　次に、図１１Ａから図１２Ｂを参照してステップＳ１９及びステップＳ２０に示すジェット強度の増減処理の一例について説明する。
　図１１Ａは、ジェット強度の増減処理の一例を示すグラフであり、横軸はジェット強度、縦軸は点火時期を示している。
　図１１Ａに示すように、ジェット強度Ｉ＿ｊｅｔが強くなるほど、点火時期出力部１０９は、点火時期を遅角方向に補正する。点火時期を遅角することにより、燃焼重心が遅れるため、副室８内の燃焼温度が低下する。これにより、ジェット強度Ｉ＿ｊｅｔを低減させることができる。 Next, an example of the jet intensity increase / decrease processing shown in steps S19 and S20 will be described with reference to FIGS. 11A to 12B.
FIG. 11A is a graph showing an example of jet intensity increase / decrease processing, in which the horizontal axis represents the jet intensity and the vertical axis represents the ignition timing.
As shown in FIG. 11A, the ignition timing output unit 109 corrects the ignition timing in the retard direction as the jet intensity I_jet becomes stronger. By retarding the ignition timing, the center of gravity of combustion is delayed, so that the combustion temperature in the sub chamber 8 is lowered. Thereby, the jet intensity I_jet can be reduced.
　また、ジェット強度Ｉ＿ｊｅｔが弱い場合、点火時期出力部１０９は、点火時期を進角方向に補正する。点火時期を進角することにより、燃焼重心が早まり、副室８内の燃焼温度が上昇する。これにより、ジェット強度Ｉ＿ｊｅｔを増加させることができる。 Further, when the jet intensity I_jet is weak, the ignition timing output unit 109 corrects the ignition timing in the advance angle direction. By advancing the ignition timing, the center of gravity of combustion is advanced and the combustion temperature in the sub chamber 8 rises. Thereby, the jet intensity I_jet can be increased.
　図１１Ｂは、ジェット強度の増減処理の他の例を示すグラフであり、横軸はジェット強度、縦軸はＥＧＲ率目標値［％］を示している。
　図１１Ｂに示すように、内燃機関制御装置２０は、ジェット強度Ｉ＿ｊｅｔに応じてＥＧＲ率目標値を制御する。すなわち、ジェット強度Ｉ＿ｊｅｔが強いほど、ＥＧＲ率目標値が高くなるように補正する。ＥＧＲ率を増加させることにより、混合気の希釈率が高まる。その結果、副室８内の燃焼温度が低下し、ジェット強度Ｉ＿ｊｅｔを低減させることができる。 FIG. 11B is a graph showing another example of jet intensity increase / decrease processing, in which the horizontal axis represents the jet intensity and the vertical axis represents the EGR rate target value [%].
As shown in FIG. 11B, the internal combustion engine control device 20 controls the EGR rate target value according to the jet intensity I_jet. That is, the stronger the jet intensity I_jet, the higher the EGR rate target value is corrected. Increasing the EGR rate increases the dilution rate of the air-fuel mixture. As a result, the combustion temperature in the sub chamber 8 is lowered, and the jet intensity I_jet can be reduced.
　また、ジェット強度Ｉ＿ｊｅｔが弱い場合、ＥＧＲ率目標値が低くなるように補正する。ＥＧＲ率を低下させることにより、混合気の希釈率が低くなる。その結果、副室８内の燃焼温度が上昇し、ジェット強度Ｉ＿ｊｅｔを増加させることができる。 If the jet intensity I_jet is weak, the EGR rate target value is corrected to be low. By lowering the EGR rate, the dilution rate of the air-fuel mixture becomes low. As a result, the combustion temperature in the sub chamber 8 rises, and the jet intensity I_jet can be increased.
　図１２Ａは、ジェット強度の増減処理の他の例を示すグラフであり、横軸はジェット強度、縦軸はＡ／Ｆ目標値を示している。
　図１２Ａに示すように、内燃機関制御装置２０は、ジェット強度Ｉ＿ｊｅｔに応じてＡ／Ｆ目標値を制御する。すなわち、ジェット強度Ｉ＿ｊｅｔが強いほど、Ａ／Ｆ目標値が高くなるように補正する。Ａ／Ｆを増加させることにより、混合気の希釈率が高まる。その結果、副室８内の燃焼温度が低下し、ジェット強度Ｉ＿ｊｅｔを低減させることができる。 FIG. 12A is a graph showing another example of jet intensity increase / decrease processing, in which the horizontal axis represents the jet intensity and the vertical axis represents the A / F target value.
As shown in FIG. 12A, the internal combustion engine control device 20 controls the A / F target value according to the jet intensity I_jet. That is, the stronger the jet intensity I_jet, the higher the A / F target value is corrected. By increasing the A / F, the dilution ratio of the air-fuel mixture is increased. As a result, the combustion temperature in the sub chamber 8 is lowered, and the jet intensity I_jet can be reduced.
　また、ジェット強度Ｉ＿ｊｅｔが弱い場合、Ａ／Ｆ目標値が低くなるように補正する。Ａ／Ｆを低下させることにより、混合気の希釈率が低くなる。その結果、副室８内の燃焼温度が上昇し、ジェット強度Ｉ＿ｊｅｔを増加させることができる。 Also, if the jet intensity I_jet is weak, the A / F target value is corrected to be low. By lowering the A / F, the dilution ratio of the air-fuel mixture becomes low. As a result, the combustion temperature in the sub chamber 8 rises, and the jet intensity I_jet can be increased.
　図１２Ｂは、ジェット強度の増減処理の他の例を示すグラフであり、横軸はジェット強度、縦軸は点火エネルギ［ｍＪ］を示している。
　図１２Ｂに示すように、内燃機関制御装置２０は、ジェット強度Ｉ＿ｊｅｔに応じて点火エネルギを制御する。すなわち、ジェット強度Ｉ＿ｊｅｔが強いほど、点火エネルギが低くなるように補正する。点火エネルギを低下させることにより、着火遅れ時期が増加して、点火時期を遅角した際と同様に、燃焼重心が遅れて、副室８内の燃焼温度が低下する。その結果、ジェット強度Ｉ＿ｊｅｔを低減させることができる。 FIG. 12B is a graph showing another example of the jet intensity increase / decrease process, in which the horizontal axis represents the jet intensity and the vertical axis represents the ignition energy [mJ].
As shown in FIG. 12B, the internal combustion engine control device 20 controls the ignition energy according to the jet intensity I_jet. That is, the stronger the jet intensity I_jet, the lower the ignition energy. By lowering the ignition energy, the ignition delay timing is increased, the combustion center of gravity is delayed, and the combustion temperature in the sub chamber 8 is lowered, as in the case of retarding the ignition timing. As a result, the jet intensity I_jet can be reduced.
　また、ジェット強度Ｉ＿ｊｅｔが弱い場合、点火エネルギが高くなるように補正する。点火エネルギを増加させることにより、着火遅れ時期を減少させ、点火時期を進角した際と同様に、燃焼重心が早まり、副室８内の燃焼温度が上昇する。その結果、ジェット強度Ｉ＿ｊｅｔを増加させることができる。 Also, if the jet intensity I_jet is weak, it is corrected so that the ignition energy becomes high. By increasing the ignition energy, the ignition delay timing is reduced, the combustion center of gravity is advanced, and the combustion temperature in the sub chamber 8 rises, as in the case of advancing the ignition timing. As a result, the jet intensity I_jet can be increased.
　なお、ジェット強度の増減処理は、上述した例に限定されるものではなく、その他各種の増減方法が適用されるものである。 The jet strength increase / decrease process is not limited to the above-mentioned example, and various other methods for increasing / decreasing the jet strength are applied.
２．第２の実施の形態例
　次に、図１３から図１５を参照して第２の実施の形態例にかかる内燃機関制御装置について説明する。
　図１３は、第２の実施の形態例にかかる内燃機関制御装置のジェット強度の推定処理の構成を示すブロック図である。図１４は、エンジン運転条件ごとのジェット強度推定時のノックセンサ振幅信頼率を示すマップである。図１５は、第２の実施の形態例にかかる内燃機関制御装置の第２ジェット強度推定部によるジェット強度の推定方法を示す図である。なお、第１の実施の形態例に内燃機関制御装置２０と共通する部分には、同一の符号を付して重複した説明を省略する。 2. Second Embodiment Example Next, the internal combustion engine control device according to the second embodiment will be described with reference to FIGS. 13 to 15.
FIG. 13 is a block diagram showing a configuration of jet strength estimation processing of the internal combustion engine control device according to the second embodiment. FIG. 14 is a map showing the knock sensor amplitude reliability at the time of jet intensity estimation for each engine operating condition. FIG. 15 is a diagram showing a method of estimating the jet strength by the second jet strength estimation unit of the internal combustion engine control device according to the second embodiment. The parts common to the internal combustion engine control device 20 in the first embodiment are designated by the same reference numerals, and duplicate description will be omitted.
　図１３に示すように、内燃機関制御装置２０Ｂは、ノックセンサ信号取得部１０１と、バンド幅・閾値取得部１０２と、クランク角情報取得部１０３と、回転変動取得部１０４と、着火時刻推定部１０５と、クランク軸加速開始時刻推定部１０６とを有している。また、内燃機関制御装置２０Ｂは、ジェット強度比較部１０８と、点火時期出力部１０９とを有している。これらの処理部の構成は、第１の実施の形態例にかかる処理部と同様であるため、その説明は省略する。 As shown in FIG. 13, the internal combustion engine control device 20B includes a knock sensor signal acquisition unit 101, a bandwidth / threshold acquisition unit 102, a crank angle information acquisition unit 103, a rotation fluctuation acquisition unit 104, and an ignition time estimation unit. It has 105 and a crank shaft acceleration start time estimation unit 106. Further, the internal combustion engine control device 20B has a jet intensity comparison unit 108 and an ignition timing output unit 109. Since the configuration of these processing units is the same as that of the processing unit according to the first embodiment, the description thereof will be omitted.
　さらに、内燃機関制御装置２０Ｂは、第１ジェット強度推定部２０７Ａと、第２ジェット強度推定部２０７Ｂと、ジェット強度選択部２０１と、信頼率β計算部２０２と、ジェット強度上限値・下限値計算部２１０とを有している。第１ジェット強度推定部２０７Ａの構成は、第１の実施の形態例にかかるジェット強度推定部１０７と同様であるため、その説明は省略する。また、第１ジェット強度推定部２０７Ａは、推定した第１ジェット強度をジェット強度選択部２０１に出力する。 Further, the internal combustion engine control device 20B includes a first jet intensity estimation unit 207A, a second jet intensity estimation unit 207B, a jet intensity selection unit 201, a reliability rate β calculation unit 202, and a jet intensity upper limit value / lower limit value calculation. It has a unit 210. Since the configuration of the first jet intensity estimation unit 207A is the same as that of the jet intensity estimation unit 107 according to the first embodiment, the description thereof will be omitted. Further, the first jet intensity estimation unit 207A outputs the estimated first jet intensity to the jet intensity selection unit 201.
　第２ジェット強度推定部２０７Ｂは、ノックセンサ４７に接続されており、ノックセンサ４７からノックセンサ信号を取得する。第２ジェット強度推定部２０７Ｂは、ノックセンサ信号に基づいて、第２ジェット強度を推定する。なお、第２ジェット強度推定部２０７Ｂによる第２ジェット強度の推定方法については、後述する。そして、第２ジェット強度推定部２０７Ｂは、推定した第２ジェット強度をジェット強度選択部２０１に出力する。 The second jet intensity estimation unit 207B is connected to the knock sensor 47 and acquires a knock sensor signal from the knock sensor 47. The second jet intensity estimation unit 207B estimates the second jet intensity based on the knock sensor signal. The method of estimating the second jet intensity by the second jet intensity estimation unit 207B will be described later. Then, the second jet intensity estimation unit 207B outputs the estimated second jet intensity to the jet intensity selection unit 201.
　ジェット強度選択部２０１は、信頼率β計算部２０２に接続されており、信頼率β計算部２０２から信頼率βが出力される。そして、ジェット強度選択部２０１は、信頼率βに応じて、第１ジェット強度と第２ジェット強度のうち指標として用いるジェット強度を選択する。ジェット強度選択部２０１は、選択したジェット強度をジェット強度比較部１０８に出力する。 The jet strength selection unit 201 is connected to the reliability rate β calculation unit 202, and the reliability rate β is output from the reliability rate β calculation unit 202. Then, the jet intensity selection unit 201 selects the jet intensity to be used as an index among the first jet intensity and the second jet intensity according to the reliability β. The jet intensity selection unit 201 outputs the selected jet intensity to the jet intensity comparison unit 108.
　例えば、ジェット強度選択部２０１は、信頼率βが所定値以下の場合、第１ジェット強度推定部２０７Ａが推定した第１ジェット強度の信頼性が高いと判断し、第１ジェット強度を選択する。また、ジェット強度選択部２０１は、信頼率βが所定値以上の場合、第２ジェット強度推定部２０７Ｂが推定した第２ジェット強度の信頼性が高いと判断し、第２ジェット強度を選択する。 For example, when the reliability rate β is equal to or less than a predetermined value, the jet intensity selection unit 201 determines that the reliability of the first jet intensity estimated by the first jet intensity estimation unit 207A is high, and selects the first jet intensity. Further, when the reliability rate β is equal to or higher than a predetermined value, the jet intensity selection unit 201 determines that the reliability of the second jet intensity estimated by the second jet intensity estimation unit 207B is high, and selects the second jet intensity.
　信頼率β計算部２０２は、アクセル開度センサ１２に接続されている。そして、信頼率β計算部２０２には、アクセル開度センサ１２からスロットル開度やエンジンの回転数情報が入力される。そして、信頼率β計算部２０２は、図１４に示すエンジン運転条件ごとのジェット強度推定時のノックセンサ振幅信頼率βを示すマップを有している。図１４における横軸はエンジンの回転数［ｒｐｍ］、縦軸はエンジン負荷ＩＭＥＰ［ｒｐｍ］を示している。信頼率β計算部２０２は、エンジンの運転条件に基づいて、図１４に示すマップから信頼率βを計算し、ジェット強度選択部２０１に出力する。 The reliability rate β calculation unit 202 is connected to the accelerator opening sensor 12. Then, the throttle opening degree and the engine speed information are input from the accelerator opening degree sensor 12 to the reliability rate β calculation unit 202. The reliability β calculation unit 202 has a map showing the knock sensor amplitude reliability β at the time of jet intensity estimation for each engine operating condition shown in FIG. In FIG. 14, the horizontal axis represents the engine speed [rpm], and the vertical axis represents the engine load IMEP [rpm]. The reliability β calculation unit 202 calculates the reliability β from the map shown in FIG. 14 based on the operating conditions of the engine, and outputs the calculation to the jet intensity selection unit 201.
　第２の実施の形態例にかかるジェット強度上限値・下限値計算部２１０は、第１ジェット強度推定部２０７Ａと第２ジェット強度推定部２０７Ｂに対する上限値及び下限値を計算する。すなわち、ジェット強度上限値・下限値計算部２１０は、ジェット強度選択部２０１が選択したジェット強度に応じて、上限値及び下限値を計算する。そして、ジェット強度上限値・下限値計算部２１０は、計算した上限値及び下限値をジェット強度比較部１０８に出力する。 The jet intensity upper limit value / lower limit value calculation unit 210 according to the second embodiment calculates the upper limit value and the lower limit value for the first jet intensity estimation unit 207A and the second jet intensity estimation unit 207B. That is, the jet intensity upper limit value / lower limit value calculation unit 210 calculates the upper limit value and the lower limit value according to the jet intensity selected by the jet intensity selection unit 201. Then, the jet intensity upper limit value / lower limit value calculation unit 210 outputs the calculated upper limit value and lower limit value to the jet intensity comparison unit 108.
　次に、第２ジェット強度推定部２０７Ｂによる第２ジェット強度の推定方法について図１５を参照して説明する。
　ここで、第１ジェット強度推定部２０７Ａでは、上述したように、ノックセンサ信号をジェットによる着火時刻の推定のみに使用し、ノックセンサ信号の振幅情報は使用していない。しかしながら、ノックセンサ信号の振幅情報にも、着火時の振動が含まれている。そのため、エンジンの機械振動が比較的少ない低回転時や、エンジンの回転変動が少なく、クランク角センサ４９の回転変動（回転変化量Δω）の検知精度が悪化する低負荷時などでは、ノックセンサ信号の振幅情報をジェット強度の推定に用いることができる。 Next, a method of estimating the second jet intensity by the second jet intensity estimation unit 207B will be described with reference to FIG.
Here, as described above, the first jet intensity estimation unit 207A uses the knock sensor signal only for estimating the ignition time by the jet, and does not use the amplitude information of the knock sensor signal. However, the amplitude information of the knock sensor signal also includes vibration at the time of ignition. Therefore, the knock sensor signal is used at low rotation where the mechanical vibration of the engine is relatively small, or at low load when the rotation fluctuation of the engine is small and the detection accuracy of the rotation fluctuation (rotation change amount Δω) of the crank angle sensor 49 deteriorates. The amplitude information of can be used to estimate the jet intensity.
　図１５（ａ）から図１５（ｃ）に示すように、第２ジェット強度推定部２０７Ｂは、着火時刻推定部１０５と同様に、ノックセンサ信号に対してフィルタ処理を行い、フィルタ出力値を絶対値に変換し、振動の振幅を取得する。そして、第２ジェット強度推定部２０７Ｂは、図１５（ｃ）に示すように、点火時期より後、かつ排気弁開時期より前の範囲でノックセンサ信号の振幅最大値を第２ジェット強度Ｉｊｅｔ－ｋｏｃｋｓｅｎｓｏｒとして推定する。 As shown in FIGS. 15 (a) to 15 (c), the second jet intensity estimation unit 207B performs a filter process on the knock sensor signal in the same manner as the ignition time estimation unit 105, and sets the filter output value to absolute value. Convert to a value and get the amplitude of the vibration. Then, as shown in FIG. 15 (c), the second jet intensity estimation unit 207B sets the maximum amplitude value of the knock sensor signal in the range after the ignition timing and before the exhaust valve opening timing. -Estimated as kick sensor.
　その他の構成は、第１の実施の形態例にかかる内燃機関制御装置２０と同様であるため、それらの説明は省略する。このような構成を有する内燃機関制御装置２０Ｂによっても、上述した第１の実施の形態例にかかる内燃機関制御装置２０と同様の作用効果を得ることができる。 Since other configurations are the same as those of the internal combustion engine control device 20 according to the first embodiment, the description thereof will be omitted. The internal combustion engine control device 20B having such a configuration can also obtain the same operation and effect as the internal combustion engine control device 20 according to the first embodiment described above.
　また、第２の実施の形態例にかかる内燃機関制御装置２０Ｂによれば、運転状態に応じて各センサの信頼度を設定し、ジェット強度を推定する際に用いるセンサ情報を決定している。これにより、内燃機関１００に設けた各センサの性能を最大限発揮することができ、ジェット強度の推定精度の向上を図ることができる。 Further, according to the internal combustion engine control device 20B according to the second embodiment, the reliability of each sensor is set according to the operating state, and the sensor information used when estimating the jet intensity is determined. As a result, the performance of each sensor provided in the internal combustion engine 100 can be maximized, and the accuracy of estimating the jet strength can be improved.
　なお、第２の実施の形態例にかかる内燃機関制御装置２０Ｂでは、信頼率βを閾値として用いることで、第１ジェット強度推定部２０７Ａが推定した第１ジェット強度と、第２ジェット強度推定部２０７Ｂが推定した第２ジェット強度とを切り替える例を説明したが、これに限定されるものではない。例えば、各ジェット強度推定部２０７Ａ、２０７Ｂが推定したジェット強度に重み付けを行い平均した値をジェット強度として用いてもよい。さらに、ノックセンサ４７及びクランク角センサ４９の仕様から推定されるジェット強度の推定誤差を事前誤差分布σとして予め計算し、この事前誤差分布σを信頼率βの計算に用いてもよい。 In the internal combustion engine control device 20B according to the second embodiment, the first jet intensity estimated by the first jet intensity estimation unit 207A and the second jet intensity estimation unit are used as the threshold value of the reliability β. An example of switching between the second jet intensity estimated by the 207B and the second jet intensity has been described, but the present invention is not limited to this. For example, the jet intensities estimated by the jet intensities estimation units 207A and 207B may be weighted and the average value may be used as the jet intensities. Further, the estimation error of the jet intensity estimated from the specifications of the knock sensor 47 and the crank angle sensor 49 may be calculated in advance as the prior error distribution σ, and this prior error distribution σ may be used for the calculation of the reliability rate β.
３．第３の実施の形態例
　次に、第３の実施の形態例にかかる内燃機関制御装置について図１６を参照して説明する。
　図１６は、ジェット強度と初期燃焼機関の相関関係を示すグラフである。横軸は主燃焼室１４ａの筒内圧に基づいた燃焼解析装置により求めた初期燃焼機関（点火時期－ＭＦＢ０２）を示している。また、縦軸はジェット強度（副燃焼室と主燃焼室の差圧の最大値）を示している。 3. 3. Example of Third Embodiment Next, the internal combustion engine control device according to the third embodiment will be described with reference to FIG.
FIG. 16 is a graph showing the correlation between the jet intensity and the initial combustion engine. The horizontal axis shows the initial combustion engine (ignition timing-MFB02) obtained by a combustion analyzer based on the in-cylinder pressure of the main combustion chamber 14a. The vertical axis shows the jet strength (maximum value of the differential pressure between the sub-combustion chamber and the main combustion chamber).
　図１６に示すように、初期燃焼機関とジェット強度には、高い相関があることが分かる。すなわち、ジェット強度の推定方法は、ジェット点火における初期燃焼速度の推定方法と読み替えることが可能である。そのため、第３の実施の形態例にかかる内燃機関制御装置では、ジェット強度の推定だけでなく、初期燃焼機関の推定を行う。これにより、ジェット強度の推定を行うことで、初期燃焼機関を推定し、エンジン制御全般に適用することができる。 As shown in FIG. 16, it can be seen that there is a high correlation between the initial combustion engine and the jet intensity. That is, the method of estimating the jet intensity can be read as the method of estimating the initial combustion rate in jet ignition. Therefore, in the internal combustion engine control device according to the third embodiment, not only the jet intensity is estimated but also the initial combustion engine is estimated. As a result, by estimating the jet intensity, the initial combustion engine can be estimated and applied to overall engine control.
４．第４の実施の形態例
　次に、第４の実施の形態例にかかる内燃機関制御装置について図１７を参照して説明する。
　図１７は、燃焼１サイクルにおける主燃焼室１４ａの筒内圧及びトルクの変動を示す図である。縦軸にトルク［Ｎｍ］と筒内圧［ＭＰａ］を示し、横軸に燃焼１サイクルのクランク軸４８の回転角度を示している。 4. Example of Fourth Embodiment Next, the internal combustion engine control device according to the fourth embodiment will be described with reference to FIG.
FIG. 17 is a diagram showing fluctuations in the in-cylinder pressure and torque of the main combustion chamber 14a in one combustion cycle. The vertical axis shows the torque [Nm] and the in-cylinder pressure [MPa], and the horizontal axis shows the rotation angle of the crank shaft 48 in one combustion cycle.
　第１の実施の形態例にかかる内燃機関制御装置２０では、回転数変化率ｄωをジェット強度として推定している。しかしながら、図１７に示すように、クランク軸４８の加速開始タイミングが上死点に近い場合、燃焼圧がトルクにほとんど変換されず、トルクの値がゼロとなっている。その結果、圧力変動が回転変動として検知できなくなるおそれがある。 In the internal combustion engine control device 20 according to the first embodiment, the rotation speed change rate dω is estimated as the jet intensity. However, as shown in FIG. 17, when the acceleration start timing of the crank shaft 48 is close to the top dead center, the combustion pressure is hardly converted into torque, and the torque value is zero. As a result, the pressure fluctuation may not be detected as the rotation fluctuation.
　そのため、第４の実施の形態例にかかる内燃機関制御装置では、ジェット強度推定部１０７が数８を用いて回転数変化率ｄωを推定する。その後、ジェット強度推定部１０７は、数４に基づいて、ピストン機構による圧力－トルク変換の関係性が考慮された主燃焼室１４ａの筒内圧Ｐｃｏｍｂを算出し、ジェット強度を推定する。または、各クランク角度において数４を用いて筒内圧Ｐｃｏｍｂを算出し、その結果から傾きｄＰ／ｄθを算出することで、ジェット強度を推定する。 Therefore, in the internal combustion engine control device according to the fourth embodiment, the jet intensity estimation unit 107 estimates the rotation speed change rate dω using the equation 8. After that, the jet strength estimation unit 107 calculates the in-cylinder pressure Pcomb of the main combustion chamber 14a in consideration of the pressure-torque conversion relationship by the piston mechanism based on Equation 4, and estimates the jet strength. Alternatively, the jet strength is estimated by calculating the in-cylinder pressure P comb using Equation 4 at each crank angle and calculating the slope dP / dθ from the result.
　これにより、第４の実施の形態例にかかる内燃機関制御装置によれば、上死点付近のピストン機構の特異点によりジェット強度が正しく検知できなくなることを防ぐことができ、ジェット強度の推定精度の向上を図ることができる。また、第４の実施の形態例にかかるジェット強度推定部１０７は、ジェットの発生タイミングが上死点に近いと判定された時のみ、数４を用いて筒内圧Ｐｃｏｍｂまたはその傾きｄＰ／ｄθを算出してもよい。これにより、計算負荷の軽減を図ることができる。 As a result, according to the internal combustion engine control device according to the fourth embodiment, it is possible to prevent the jet intensity from being unable to be detected correctly due to the singular point of the piston mechanism near the top dead center, and the estimation accuracy of the jet intensity can be prevented. Can be improved. Further, the jet intensity estimation unit 107 according to the fourth embodiment uses the equation 4 only when it is determined that the jet generation timing is close to the top dead center, and the in-cylinder pressure P comb or its inclination dP / dθ is used. May be calculated. As a result, the calculation load can be reduced.
５．第５の実施の形態例
　次に、図１８から図１９を参照して第５の実施の形態例にかかる内燃機関制御装置について説明する。 5. Example of Fifth Embodiment Next, the internal combustion engine control device according to the fifth embodiment will be described with reference to FIGS. 18 to 19.
　上述した第１の実施の形態例にかかる内燃機関制御装置２０では、クランク角センサ４９のクランク情報に基づいて、ジェットの終了タイミングを検出している。これに対して、第５の実施の形態例にかかる内燃機関制御装置では、点火コイル１６の信号に基づいて、ジェットの終了タイミングを検出している。 The internal combustion engine control device 20 according to the first embodiment described above detects the end timing of the jet based on the crank information of the crank angle sensor 49. On the other hand, in the internal combustion engine control device according to the fifth embodiment, the jet end timing is detected based on the signal of the ignition coil 16.
　図１８は、火炎ジェットの変化の様子と、圧力差ΔＰの例を示す図である。図１８の下部には、クランク角度に対する圧力差ΔＰのグラフが示される。そして、図１８の上部に示す火炎ジェットの変化の様子を示す説明図（ａ）～（ｃ）の符号が、圧力差ΔＰのグラフに付加される。なお、図中では、副燃焼室を「副室」と略記し、主燃焼室１４ａを「主室」と略記する。また、説明図（ａ）～（ｃ）内に示す矢印は、火炎の伝播方向を表す。 FIG. 18 is a diagram showing a state of change of the flame jet and an example of the pressure difference ΔP. At the bottom of FIG. 18, a graph of the pressure difference ΔP with respect to the crank angle is shown. Then, the reference numerals of explanatory views (a) to (c) showing the state of change of the flame jet shown in the upper part of FIG. 18 are added to the graph of the pressure difference ΔP. In the figure, the sub-combustion chamber is abbreviated as "sub-combustion chamber", and the main combustion chamber 14a is abbreviated as "main chamber". Further, the arrows shown in the explanatory views (a) to (c) indicate the propagation direction of the flame.
　図１８の説明図（ａ）に示すように、ピストン１８が上昇中に、点火プラグ１７による点火が行われる。そして、副燃焼室内に火炎が形成され、副燃焼室内を火炎が伝播する。この時、図１８の下部のグラフより、圧力差ΔＰが正の値を示すことが分かる。 As shown in the explanatory view (a) of FIG. 18, ignition is performed by the spark plug 17 while the piston 18 is rising. Then, a flame is formed in the sub-combustion chamber, and the flame propagates in the sub-combustion chamber. At this time, it can be seen from the graph at the bottom of FIG. 18 that the pressure difference ΔP shows a positive value.
　次に、図１８の説明図（ｂ）に示すように、ピストン１８が上死点を経て下降し始めるが、副燃焼室から主燃焼室１４ａに火炎が噴出する。この時にも、図１８の下部のグラフより、圧力差ΔＰが正の値を示すことが分かる。 Next, as shown in the explanatory view (b) of FIG. 18, the piston 18 begins to descend through the top dead center, but a flame is ejected from the sub-combustion chamber to the main combustion chamber 14a. At this time as well, it can be seen from the graph at the bottom of FIG. 18 that the pressure difference ΔP shows a positive value.
　次に、図１８の説明図（ｃ）に示すように、主燃焼室１４ａに噴出した火炎ジェットにより、主燃焼室１４ａの混合気が燃焼し、ピストン１８が下降する。そして、副燃焼室内の圧力が負圧になる。この時、図１８の下部のグラフより、圧力差ΔＰが負の値を示すことが分かる。このため、主燃焼室１４ａから副燃焼室へ火炎が吹き戻る現象が発生する。なお、吹き戻りが発生しているということは、すでにジェットによる主燃焼室１４ａ内の混合気への点火が完了していることを示唆している。そのため、この吹き戻りを検知した時刻、すなわちジェット終了時刻ｔｂｕｒｎにて、回転数変化率ｄωの計算を打ち切る。そのため、回転数変化率ｄωは、下記数１１により算出される Next, as shown in the explanatory view (c) of FIG. 18, the flame jet ejected into the main combustion chamber 14a burns the air-fuel mixture in the main combustion chamber 14a, and the piston 18 descends. Then, the pressure in the sub-combustion chamber becomes a negative pressure. At this time, it can be seen from the graph at the bottom of FIG. 18 that the pressure difference ΔP shows a negative value. Therefore, a phenomenon occurs in which a flame blows back from the main combustion chamber 14a to the sub-combustion chamber. The fact that the blowback has occurred suggests that the jet has already ignited the air-fuel mixture in the main combustion chamber 14a. Therefore, the calculation of the rotation speed change rate dω is stopped at the time when this blowback is detected, that is, at the jet end time tburn . Therefore, the rotation speed change rate dω is calculated by the following equation 11.
Figure JPOXMLDOC01-appb-M000011
Figure JPOXMLDOC01-appb-M000011
　すなわち、第５の実施の形態例にかかるジェット強度推定部は、加速開始時刻ｔａｃｃ又はジェット開始時刻ｔｊｅｔからジェット終了時刻ｔｂｕｒｎまでの間の回転数変化量Δωに基づいて、回転数変化率ｄωを算出している。 That is, the jet intensity estimation unit according to the fifth embodiment changes the rotation speed based on the rotation speed change amount Δω between the acceleration start time t acc or the jet start time t jet and the jet end time t burn . The rate dω is calculated.
　図１８の説明図（ｂ）から説明図（ｃ）に示すように、副燃焼室内における混合気の流動が大きく変化する。そして、点火プラグ１７の電極間の乱れが大きく変化すると共に、電極間の抵抗Ｒｓｐも変化する。 As shown in the explanatory views (b) to (c) of FIG. 18, the flow of the air-fuel mixture in the sub-combustion chamber changes significantly. Then, the turbulence between the electrodes of the spark plug 17 changes significantly, and the resistance Rsp between the electrodes also changes.
　図１８の説明図（ｃ）に示した吹き戻りのタイミングは、クランク角度が０～２０［ｄｅｇ．ＡＴＤＣ］の範囲に収まる。また、クランク角度が０～２０［ｄｅｇ．ＡＴＤＣ］の範囲より遅角化した場合は、既に膨張行程に入っているため、主燃焼室１４ａから副燃焼室へ火炎が吹き戻ることはない。一方、クランク角度が０～２０［ｄｅｇ．ＡＴＤＣ］の範囲より進角化した場合は、エンジン１００内の圧力が高くなり過ぎるため、適用範囲外の条件となる。 The timing of blowback shown in the explanatory view (c) of FIG. 18 is such that the crank angle is 0 to 20 [deg. It falls within the range of [ATDC]. In addition, the crank angle is 0 to 20 [deg. When the angle is retarded from the range of [ATDC], the flame does not blow back from the main combustion chamber 14a to the sub-combustion chamber because it has already entered the expansion stroke. On the other hand, the crank angle is 0 to 20 [deg. If the angle is advanced beyond the range of [ATDC], the pressure in the engine 100 becomes too high, which is a condition outside the applicable range.
　次に、図１９を参照して吹き戻りのタイミングの検出方法について説明する。
　図１９は、燃焼タイミングの検出を説明するための第１の制御タイムチャートである。図１９の上から順に、点火信号、放電２次電流の変化が示される。また、図８の横軸は時間を表す。 Next, a method of detecting the timing of blowback will be described with reference to FIG.
FIG. 19 is a first control time chart for explaining the detection of the combustion timing. Changes in the ignition signal and the secondary discharge current are shown in order from the top of FIG. The horizontal axis in FIG. 8 represents time.
　第５の実施の形態例にかかる内燃機関制御装置は、点火信号を点火コイル１６に出力する。点火信号のパルス幅は、チャージ期間ｔｃとして表され、チャージ期間ｔｃに、１次コイルが通電される。 The internal combustion engine control device according to the fifth embodiment outputs an ignition signal to the ignition coil 16. The pulse width of the ignition signal is expressed as the charge period ct, and the primary coil is energized during the charge period ct.
　内燃機関制御装置は、チャージ期間ｔｃの経過後、点火信号を立下げることで、点火プラグ１７の放電開始を制御する。点火プラグ１７では、放電期間ｔｄにわたって電極間で放電される。内燃機関制御装置は、点火プラグ１７からフィードバックされる電極間の放電時における放電２次電流の値に基づいて、放電２次電流の電流変化タイミングを検出する。クランク角度が０～２０［ｄｅｇ．ＡＴＤＣ］として表される火炎の吹き戻り期間には、主燃焼室１４から副室８に火炎が吹き戻るので、放電２次電流の値が激しく変化する。そして、内燃機関制御装置は、放電２次電流の値が激しく変化した時刻を、吹き戻り時刻ｔｂｕｒｎとして検出する。 The internal combustion engine control device controls the start of discharge of the spark plug 17 by lowering the ignition signal after the lapse of the charge period tk. In the spark plug 17, discharge is performed between the electrodes over the discharge period td. The internal combustion engine control device detects the current change timing of the secondary discharge current based on the value of the secondary discharge current at the time of discharge between the electrodes fed back from the spark plug 17. Crank angle is 0 to 20 [deg. During the flame blowback period represented as [ATDC], the flame blows back from the main combustion chamber 14 to the sub chamber 8, so that the value of the secondary discharge current changes drastically. Then, the internal combustion engine control device detects the time when the value of the secondary discharge current changes drastically as the blowback time tburn .
　このように、第５の実施の形態例にかかる内燃機関制御装置では、ジェットの開始と終了タイミングの両方を正確に検出することができ、回転数変化率ｄωを実際の回転数挙動に近づけることができる。その結果、ジェット強度の推定精度の向上を図ることができる。 As described above, in the internal combustion engine control device according to the fifth embodiment, both the start and end timings of the jet can be accurately detected, and the rotation speed change rate dω is brought closer to the actual rotation speed behavior. Can be done. As a result, the accuracy of estimating the jet strength can be improved.
６．内燃機関の変形例
　次に、図２０を参照して内燃機関の変形例について説明する。
　図２０は、変形例にかかる内燃機関の副室周りの構成を拡大して示す概略構成図である。 6. Modification example of the internal combustion engine Next, a modification of the internal combustion engine will be described with reference to FIG.
FIG. 20 is a schematic configuration diagram showing an enlarged configuration around the auxiliary chamber of the internal combustion engine according to the modified example.
　図１に示す内燃機関１００は、インジェクタ１３がシリンダ１４の側面部に設けられ、副室８内には点火プラグ１７のみが設置されるパッシブ型の内燃機関である。なお、本発明の内燃機関制御装置が適用される内燃機関としては、図１に示すパッシブ型に限定されるものではない。 The internal combustion engine 100 shown in FIG. 1 is a passive internal combustion engine in which an injector 13 is provided on a side surface of a cylinder 14 and only a spark plug 17 is installed in an auxiliary chamber 8. The internal combustion engine to which the internal combustion engine control device of the present invention is applied is not limited to the passive type shown in FIG.
　本発明の内燃機関制御装置が適用される内燃機関としては、例えば、図２０に示すような、インジェクタ１３Ｃが副室８内に設置されるアクティブ型の内燃機関を適用してもよい。そして、インジェクタ１３Ｃは、副室８内に燃料を直接噴射する。アクティブ型の場合、副室噴射孔８ａを通じて主燃焼室１４ａ側から供給される空気とインジェクタ１３Ｃから供給される燃料によって、副室８内の空燃比を着火性が良好となるように制御することができる。その結果、燃焼安静性を向上させることが可能となる。 As the internal combustion engine to which the internal combustion engine control device of the present invention is applied, for example, an active type internal combustion engine in which the injector 13C is installed in the sub chamber 8 as shown in FIG. 20 may be applied. Then, the injector 13C directly injects fuel into the sub chamber 8. In the case of the active type, the air-fuel ratio in the sub chamber 8 is controlled so that the ignitability is good by the air supplied from the main combustion chamber 14a side through the sub chamber injection hole 8a and the fuel supplied from the injector 13C. Can be done. As a result, it becomes possible to improve the combustion rest.
　なお、上述しかつ図面に示した実施の形態に限定されるものではなく、特許請求の範囲に記載した発明の要旨を逸脱しない範囲内で種々の変形実施が可能である。 It should be noted that the embodiment is not limited to the embodiment described above and shown in the drawings, and various modifications can be carried out within a range that does not deviate from the gist of the invention described in the claims.
　例えば、上述した各実施の形態は本発明を分かりやすく説明するために装置及びシステムの構成を詳細かつ具体的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ない。また、ここで説明した実施の形態の構成の一部を他の実施の形態の構成に置き換えることは可能であり、さらにはある実施の形態の構成に他の実施の形態の構成を加えることも可能である。また、各実施の形態の構成の一部について、他の構成の追加、削除、置換をすることも可能である。 For example, each of the above-described embodiments describes the configurations of the apparatus and the system in detail and concretely in order to explain the present invention in an easy-to-understand manner, and is not necessarily limited to those including all the described configurations. Further, it is possible to replace a part of the configuration of the embodiment described here with the configuration of another embodiment, and further, it is possible to add the configuration of another embodiment to the configuration of one embodiment. It is possible. It is also possible to add, delete, or replace a part of the configuration of each embodiment with another configuration.
　また、制御線や情報線は説明上必要と考えられるものを示しており、製品上必ずしも全ての制御線や情報線を示しているとは限らない。実際には殆ど全ての構成が相互に接続されていると考えてもよい。 In addition, the control lines and information lines indicate what is considered necessary for explanation, and not all control lines and information lines are necessarily shown on the product. In practice, it can be considered that almost all configurations are interconnected.
　　２…電子制御スロットル弁、　３…吸気圧センサ、　４…過給機、　５…可変バルブ、　６…吸気管、　８…副室、　８ａ…副室噴射孔、　１３、１３Ｂ、１３Ｃ…インジェクタ、　１４…シリンダ、　１４ａ…主燃焼室、　１５…排気管、　１６…点火コイル、　１７…点火プラグ、　１８…ピストン、　２０、２０Ｂ…ＥＣＵ（内燃機関制御装置）、　２１…入力回路、　２２…入出力ポート、　２３ａ…ＣＰＵ、　２３ｂ…ＲＯＭ、　２３ｃ…ＲＡＭ、　２４…点火制御部、　４７…ノックセンサ、　４８…クランク軸、　４９…クランク角センサ、　１００…エンジン（内燃機関）、　１０１…ノックセンサ信号取得部、　１０２…バンド幅・閾値取得部、　１０３…クランク角情報取得部、　１０４…回転変動取得部、　１０５…着火時刻推定部、　１０６…クランク軸加速開始時刻推定部（着火時刻補正部）、　１０７…ジェット強度推定部、　１０８…ジェット強度比較部、　１０９…点火時期出力部、　１１０、２１０…ジェット強度上限値・下限値計算部、　２０１…ジェット強度選択部、　２０２…信頼率β計算部、　２０７Ａ…第１ジェット強度推定部、　２０７Ｂ…第２ジェット強度推定部 2 ... Electronically controlled throttle valve, 3 ... Intake pressure sensor, 4 ... Supercharger, 5 ... Variable valve, 6 ... Intake pipe, 8 ... Sub chamber, 8a ... Sub chamber injection hole, 13, 13B, 13C ... Injector, 14 ... cylinder, 14a ... main combustion chamber, 15 ... exhaust pipe, 16 ... ignition coil, 17 ... spark plug, 18 ... piston, 20, 20B ... ECU (internal combustion engine control device), 21 ... input circuit, 22 ... input / output port , 23a ... CPU, 23b ... ROM, 23c ... RAM, 24 ... ignition control unit, 47 ... knock sensor, 48 ... crank shaft, 49 ... crank angle sensor, 100 ... engine (internal combustion engine), 101 ... knock sensor signal acquisition unit , 102 ... Band width / threshold acquisition unit, 103 ... Crank angle information acquisition unit, 104 ... Rotation fluctuation acquisition unit, 105 ... Ignition time estimation unit, 106 ... Crank shaft acceleration start time estimation unit (ignition time correction unit), 107 ... Jet intensity estimation unit, 108 ... Jet intensity comparison unit, 109 ... Ignition timing output unit, 110, 210 ... Jet intensity upper limit / lower limit calculation unit, 201 ... Jet intensity selection unit, 202 ... Reliability β calculation unit, 207A ... 1st jet strength estimation unit, 207B ... 2nd jet strength estimation unit

Claims (8)

  1. 　ピストンに面する主燃焼室と、前記主燃焼室に連通する副燃焼室と、前記副燃焼室の内部に取り付けられる点火プラグと、前記ピストンに連結されるクランク軸と、クランク軸の回転角度を検出するクランク角センサと、前記主燃焼室を形成するシリンダと、前記シリンダの振動を検出するノックセンサと、を備えた内燃機関を制御する内燃機関制御装置において、
    　前記ノックセンサが検出したノックセンサ信号に基づいて、前記副燃焼室から噴射されたジェットによる主燃焼室の混合気の着火時刻を推定する着火時刻推定部と、
    前記クランク角センサが検出したクランク角情報を取得するクランク角情報取得部と、
    　前記クランク角情報に基づいて、前記着火時刻よりも後に発生する回転数変化量を算出する回転変動取得部と、
    　前記回転変動取得部が算出した前記回転数変化量と前記着火時刻推定部が推定した前記着火時刻に基づいて、前記着火時刻より後に発生する回転数変化率を算出し、ジェット強度を推定するジェット強度推定部と、
    　を備えた内燃機関制御装置。     The main combustion chamber facing the piston, the sub-combustion chamber communicating with the main combustion chamber, the ignition plug installed inside the sub-combustion chamber, the crank shaft connected to the piston, and the rotation angle of the crank shaft. In an internal combustion engine control device that controls an internal combustion engine including a crank angle sensor for detection, a cylinder forming the main combustion chamber, and a knock sensor for detecting vibration of the cylinder.
    An ignition time estimation unit that estimates the ignition time of the air-fuel mixture in the main combustion chamber by the jet injected from the sub-combustion chamber based on the knock sensor signal detected by the knock sensor.
    A crank angle information acquisition unit that acquires crank angle information detected by the crank angle sensor, and a crank angle information acquisition unit.
    Based on the crank angle information, a rotation fluctuation acquisition unit that calculates the amount of rotation speed change that occurs after the ignition time, and a rotation fluctuation acquisition unit.
    A jet that estimates the jet intensity by calculating the rotation speed change rate that occurs after the ignition time based on the rotation speed change amount calculated by the rotation fluctuation acquisition unit and the ignition time estimated by the ignition time estimation unit. Strength estimation unit and
    Internal combustion engine control device equipped with.
  2. 　前記着火時刻推定部は、前記ノックセンサ信号に対してフィルタ処理を行い、フィルタ処理を行ったフィルタ出力値から前記着火時刻を推定する
    　請求項１に記載の内燃機関制御装置。     The internal combustion engine control device according to claim 1, wherein the ignition time estimation unit performs filter processing on the knock sensor signal and estimates the ignition time from the filtered output value of the filter.
  3. 　ピストン機構に基づいて、前記着火時刻推定部が推定した前記着火時刻を補正する着火時刻補正部をさらに備え、
    　前記ジェット強度推定部は、前記着火時刻補正部が補正した着火時刻と、前記回転数変化量に基づいて、前記回転数変化率を算出し、前記ジェット強度を推定する
    　請求項１に記載の内燃機関制御装置。     An ignition time correction unit for correcting the ignition time estimated by the ignition time estimation unit based on the piston mechanism is further provided.
    The internal combustion engine according to claim 1, wherein the jet intensity estimation unit calculates the rotation speed change rate based on the ignition time corrected by the ignition time correction unit and the rotation speed change amount, and estimates the jet intensity. Engine control device.
  4. 　前記回転数変化量と前記着火時刻に基づいて、前記回転数変化率を算出し、第１ジェット強度を推定する第１ジェット強度推定部と、
    　前記ノックセンサ信号に基づいて、第２ジェット強度を推定する第２ジェット強度推定部と、
    　備えた請求項１に記載の内燃機関制御装置。     A first jet strength estimation unit that calculates the rotation speed change rate based on the rotation speed change amount and the ignition time and estimates the first jet strength, and
    A second jet strength estimation unit that estimates the second jet strength based on the knock sensor signal, and a second jet strength estimation unit.
    The internal combustion engine control device according to claim 1.
  5. 　前記第１ジェット強度と前記第２ジェット強度のうち指標として用いるジェット強度を選択するジェット強度選択部を
    　さらに備えた請求項４に記載の内燃機関制御装置。     The internal combustion engine control device according to claim 4, further comprising a jet strength selection unit that selects a jet strength to be used as an index among the first jet strength and the second jet strength.
  6. 　前記ジェット強度推定部は、前記回転数変化率から前記主燃焼室の筒内圧を推定し、前記筒内圧から前記ジェット強度を推定する
    　請求項１に記載の内燃機関制御装置。     The internal combustion engine control device according to claim 1, wherein the jet strength estimation unit estimates the in-cylinder pressure of the main combustion chamber from the rotation speed change rate, and estimates the jet strength from the in-cylinder pressure.
  7. 　前記ジェット強度推定部は、
    　前記点火プラグの点火動作を制御するに点火コイルの信号に基づいて、ジェット終了時刻を検出し、
    　前記回転数変化率は、前記着火時刻から前記ジェット終了時刻の間の前記回転数変化量に基づいて、前記回転数変化率を算出する
    　請求項１に記載の内燃機関制御装置。     The jet strength estimation unit
    The jet end time is detected based on the signal of the ignition coil to control the ignition operation of the spark plug.
    The internal combustion engine control device according to claim 1, wherein the rotation speed change rate calculates the rotation speed change rate based on the rotation speed change amount between the ignition time and the jet end time.
  8. 　前記ジェット強度推定部が推定した前記ジェット強度に基づいて、点火時期、燃料噴射量、点火エネルギ及びＥＧＲバルブ開度のうち少なくとの一つ以上のパラメータを補正する
    　請求項１に記載の内燃機関制御装置。     The internal combustion engine according to claim 1, wherein one or more parameters of ignition timing, fuel injection amount, ignition energy, and EGR valve opening degree are corrected based on the jet intensity estimated by the jet intensity estimation unit. Control device.
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JP2017120035A (en) * 2015-12-28 2017-07-06 川崎重工業株式会社 Gas engine system
JP2018178966A (en) * 2017-04-21 2018-11-15 株式会社デンソー Device for controlling internal combustion engine and method for controlling internal combustion engine

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