Classifications

• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
  • F02D—CONTROLLING COMBUSTION ENGINES
  • F02D41/00—Electrical control of supply of combustible mixture or its constituents
  • F02D41/02—Circuit arrangements for generating control signals
  • F02D41/04—Introducing corrections for particular operating conditions
  • F02D41/047—Taking into account fuel evaporation or wall wetting
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
  • F02P—IGNITION, OTHER THAN COMPRESSION IGNITION, FOR INTERNAL-COMBUSTION ENGINES; TESTING OF IGNITION TIMING IN COMPRESSION-IGNITION ENGINES
  • F02P5/00—Advancing or retarding ignition; Control therefor
  • F02P5/04—Advancing or retarding ignition; Control therefor automatically, as a function of the working conditions of the engine or vehicle or of the atmospheric conditions
  • F02P5/145—Advancing or retarding ignition; Control therefor automatically, as a function of the working conditions of the engine or vehicle or of the atmospheric conditions using electrical means
  • F02P5/15—Digital data processing
  • F02P5/1502—Digital data processing using one central computing unit
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
  • F02P—IGNITION, OTHER THAN COMPRESSION IGNITION, FOR INTERNAL-COMBUSTION ENGINES; TESTING OF IGNITION TIMING IN COMPRESSION-IGNITION ENGINES
  • F02P5/00—Advancing or retarding ignition; Control therefor
  • F02P5/04—Advancing or retarding ignition; Control therefor automatically, as a function of the working conditions of the engine or vehicle or of the atmospheric conditions
  • F02P5/145—Advancing or retarding ignition; Control therefor automatically, as a function of the working conditions of the engine or vehicle or of the atmospheric conditions using electrical means
  • F02P5/15—Digital data processing
  • F02P5/1502—Digital data processing using one central computing unit
  • F02P5/1512—Digital data processing using one central computing unit with particular means concerning an individual cylinder
• • 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 a technique for controlling a spark ignition type internal combustion engine.
• Japanese Patent Laid-Open No. 2003-328794 discloses that during the idle-up operation after a cold start of the internal combustion engine, by reducing the expansion ratio due to the reduction of the compression ratio and significantly retarding the ignition timing, A technique for increasing the exhaust temperature is disclosed. Disclosure of the invention
• an object of the present invention is to provide a technique suitable for reducing exhaust emission in a spark ignition type internal combustion engine control system.
• the control system for an internal combustion engine according to the present invention aims to reduce the unburned fuel component discharged from the cylinder by over-igniting the ignition timing. Since the unburned fuel component discharged from the cylinder is considered to decrease as the peak of the cylinder pressure and the cylinder temperature increases, the control system for the internal combustion engine according to the present invention performs internal combustion when the ignition timing is over-advanced. A high compression ratio of the engine was also attempted.
• control system for an internal combustion engine includes an over-advance angle means for advancing the ignition timing of the spark ignition type internal combustion engine ahead of MBT, and a variable compression ratio for changing the compression ratio of the internal combustion engine.
• an over-advance angle means for advancing the ignition timing of the spark ignition type internal combustion engine ahead of MBT
• variable compression ratio for changing the compression ratio of the internal combustion engine.
• the control system for an internal combustion engine according to the present invention can suitably reduce the exhaust emission of the internal combustion engine by using both the ignition timing over-advance angle and the high compression ratio of the internal combustion engine. Further, if the ignition timing is over-advanced, the torque of the internal combustion engine may decrease, but it is also possible to compensate for the decrease in torque by increasing the compression ratio. Furthermore, since the peak of the in-cylinder pressure and the in-cylinder temperature is increased by increasing the compression ratio, it is possible to reduce the amount of advance at the time of over-advance.
• variable compression ratio mechanism can change the ratio (mechanical compression ratio) between the combustion chamber volume (the cylinder volume when the piston is at top dead center) and the cylinder volume when the piston is at bottom dead center. It may be a mechanism.
• the variable compression ratio mechanism according to the present invention is a mechanism that changes the ratio (effective compression ratio) between the combustion chamber volume and the cylinder volume when the intake valve is closed by changing the closing timing of the intake valve. May be.
• the control system for an internal combustion engine may further include first acquisition means for acquiring the in-cylinder attached fuel amount.
• the control means performs an advance angle of the ignition timing by the advance angle means when the amount of adhered fuel acquired by the first acquisition means is equal to or greater than a predetermined amount, and a compression ratio by the variable compression ratio mechanism. You may try to raise the.
• the ignition timing is reduced.
• the advance angle and the compression ratio are increased. Therefore, the unburned fuel component discharged from the cylinder is suitably reduced under the condition that the in-cylinder attached fuel amount increases.
• the first acquisition means a sensor that optically measures the thickness of the liquid film, a sensor that measures the electrical conductivity that changes depending on the thickness of the liquid film, and the like can be used.
• the first acquisition means it is also possible to use ECU that estimates and calculates the in-cylinder attached fuel amount from engine operating conditions.
• the control system for an internal combustion engine may further include second acquisition means for acquiring an air-fuel ratio of an air-fuel mixture used for combustion in a cylinder of the internal combustion engine.
• the control means may cancel the increase in the compression ratio by the variable compression ratio mechanism when the air-fuel ratio acquired by the second acquisition means is lean.
• the temperature of the exhaust gas increases.
• the reaction between the unburned fuel component and oxygen in the catalyst is promoted.
• the catalyst is activated early. If the catalyst is activated early, the unburned fuel component discharged from the cylinder is purified by the catalyst, so that a large amount of unburned fuel component is not discharged into the atmosphere.
• control unit cancels the increase in the compression ratio by the variable compression ratio mechanism and You may make it reduce the amount of advance of the time.
• an air-fuel ratio sensor disposed in the exhaust passage of the internal combustion engine An oxygen concentration sensor can be used. Further, as the second acquisition means, an ECU that calculates an air-fuel ratio from the intake air amount and the fuel injection amount can be used.
• Fig. 2 is a diagram showing the relationship between the unburned fuel component (HC) discharged from the cylinder and the ignition timing.
• FIG. 4 is a graph showing the relationship between the peak value of the in-cylinder pressure and the compression ratio.
• FIG. 5 is a graph showing the relationship between the peak value of the in-cylinder temperature and the compression ratio.
• Fig. 6 is a schematic diagram of the method for changing the compression ratio.
• FIG. 7 is a timing chart showing the execution procedure of the attached fuel reduction control.
• FIG. 8 is a flowchart showing a routine for determining the ignition timing and the compression ratio in the adhered fuel reduction control.
• FIG. 1 is a diagram illustrating a schematic configuration of an internal combustion engine control system according to the present embodiment.
• An internal combustion engine 1 shown in FIG. 1 is a four-stroke cycle spark ignition type internal combustion engine (gasoline engine) having a plurality of cylinders 2.
• the cylinder 2 of the internal combustion engine 1 communicates with the intake passage 30 through the intake port 3 and also communicates with the exhaust passage 40 through the exhaust port 4.
• the intake port 3 is provided with a fuel injection valve 5 that injects fuel into the cylinder 2.
• the intake passage 30 is provided with a throttle valve 6 that controls the amount of air flowing through the intake passage 30.
• An intake pressure sensor 7 for measuring the pressure (intake pressure) in the intake passage 30 is provided in the intake passage 30 downstream of the throttle valve 6.
• An air flow meter 8 that measures the amount of air flowing through the intake passage 30 is provided in the intake passage 30 upstream of the throttle valve 6.
• an exhaust purification device 9 is disposed in the exhaust passage 40.
• the exhaust purification device 9 includes a three-way catalyst, a storage reduction type NOx catalyst, and the like, and purifies exhaust when it is in a predetermined activation temperature range.
• the internal combustion engine 1 is provided with an intake valve 10 that opens and closes an open end of an intake port 3 that faces the inside of the cylinder 2, and an exhaust valve 11 that opens and closes an open end of the exhaust port 4 that faces the inside of the cylinder 2. ing.
• intake valve 10 and exhaust valve 11 are driven to open and close by an intake camshaft 12 and an exhaust camshaft 13, respectively.
• a spark plug 14 for igniting the air-fuel mixture in the cylinder 2 is arranged at the upper part of the cylinder 2.
• a piston 15 is slidably inserted into the cylinder 2.
• the piston 15 is connected to the crankshaft 17 through a connecting rod 16.
• a crank position sensor 18 for detecting the rotation angle of the crankshaft 17 is disposed in the vicinity of the crankshaft 17. Further, a water temperature sensor 19 for measuring the temperature of the cooling water circulating through the internal combustion engine 1 is attached to the internal combustion engine 1.
• the intake side camshaft 12 is provided with a variable valve mechanism 120 that changes the phase of the intake side camshaft 12 relative to the crankshaft 17.
• the internal combustion engine 1 configured as described above is provided with an ECU 20.
• the ECU 20 is an electronic control unit that includes a CPU, ROM, RAM, and the like. This ECU 20 is electrically connected to various sensors such as the intake pressure sensor 7, air flow meter 8, crank position sensor 18, and water temperature sensor 19 described above, and the measured values of various sensors can be input. ing.
• the ECU 20 electrically controls the fuel injection valve 5, the throttle valve 6, the spark plug 14, and the variable valve mechanism 120 based on the measurement values of the various sensors described above. For example, the ECU 20 performs attached fuel reduction control for reducing the fuel attached to the wall surface in the cylinder 2.
• the fuel tends to adhere to the wall surface in the cylinder. Most of the fuel adhering to the wall surface in the cylinder (in-cylinder attached fuel) is discharged from the cylinder without being burned without being used for combustion. At that time, if the exhaust purification device 9 is not heated to the activation temperature range, the unburned fuel component described above is discharged into the atmosphere without being purified.
• the ECU 20 advances the operation timing (ignition timing) of the spark plug 14 from the MBT when the amount of in-cylinder attached fuel is expected to increase. did.
• a sensor that optically measures the thickness of the liquid film is placed in the cylinder 2 and a sensor that measures the electrical conductivity is placed in the cylinder 2.
• a method for converting the measured value of the sensor into the in-cylinder attached fuel amount can be exemplified.

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• Engineering & Computer Science (AREA)
• Chemical & Material Sciences (AREA)
• Combustion & Propulsion (AREA)
• Mechanical Engineering (AREA)
• General Engineering & Computer Science (AREA)
• Theoretical Computer Science (AREA)
• Signal Processing (AREA)
• Output Control And Ontrol Of Special Type Engine (AREA)
• Combined Controls Of Internal Combustion Engines (AREA)
• Electrical Control Of Ignition Timing (AREA)

Applications Claiming Priority (2)

Publications (1)

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Family Applications (1)

Country Status (2)

Cited By (2)

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Citations (3)

• 2007
  • 2007-01-31 JP JP2007021432A patent/JP4353252B2/ja not_active Expired - Fee Related
• 2008
  • 2008-01-31 WO PCT/JP2008/051985 patent/WO2008099741A1/ja not_active Ceased

Patent Citations (3)

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