JP6113044B2 - Fuel injection control device and fuel injection control method for internal combustion engine - Google Patents

Fuel injection control device and fuel injection control method for internal combustion engine Download PDF

Info

Publication number
JP6113044B2
JP6113044B2 JP2013211195A JP2013211195A JP6113044B2 JP 6113044 B2 JP6113044 B2 JP 6113044B2 JP 2013211195 A JP2013211195 A JP 2013211195A JP 2013211195 A JP2013211195 A JP 2013211195A JP 6113044 B2 JP6113044 B2 JP 6113044B2
Authority
JP
Japan
Prior art keywords
fuel injection
fuel
internal combustion
combustion engine
injection
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Active
Application number
JP2013211195A
Other languages
Japanese (ja)
Other versions
JP2015075023A (en
Inventor
助川　義寛
義寛 助川
岡本　多加志
多加志 岡本
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Hitachi Astemo Ltd
Original Assignee
Hitachi Automotive Systems Ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Hitachi Automotive Systems Ltd filed Critical Hitachi Automotive Systems Ltd
Priority to JP2013211195A priority Critical patent/JP6113044B2/en
Priority to PCT/JP2014/075775 priority patent/WO2015053101A1/en
Publication of JP2015075023A publication Critical patent/JP2015075023A/en
Application granted granted Critical
Publication of JP6113044B2 publication Critical patent/JP6113044B2/en
Active legal-status Critical Current
Anticipated expiration legal-status Critical

Links

Images

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
    • F02D41/0025—Controlling engines characterised by use of non-liquid fuels, pluralities of fuels, or non-fuel substances added to the combustible mixtures
    • 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
    • F02B23/00—Other engines characterised by special shape or construction of combustion chambers to improve operation
    • F02B23/08—Other engines characterised by special shape or construction of combustion chambers to improve operation with positive ignition
    • F02B23/10—Other engines characterised by special shape or construction of combustion chambers to improve operation with positive ignition with separate admission of air and fuel into cylinder
    • F02B23/101—Other engines characterised by special shape or construction of combustion chambers to improve operation with positive ignition with separate admission of air and fuel into cylinder the injector being placed on or close to the cylinder centre axis, e.g. with mixture formation using spray guided concepts
    • 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
    • F02B23/00—Other engines characterised by special shape or construction of combustion chambers to improve operation
    • F02B23/08—Other engines characterised by special shape or construction of combustion chambers to improve operation with positive ignition
    • F02B23/10—Other engines characterised by special shape or construction of combustion chambers to improve operation with positive ignition with separate admission of air and fuel into cylinder
    • F02B23/104—Other engines characterised by special shape or construction of combustion chambers to improve operation with positive ignition with separate admission of air and fuel into cylinder the injector being placed on a side position of the cylinder
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
    • F02D—CONTROLLING COMBUSTION ENGINES
    • F02D19/00—Controlling engines characterised by their use of non-liquid fuels, pluralities of fuels, or non-fuel substances added to the combustible mixtures
    • F02D19/06—Controlling engines characterised by their use of non-liquid fuels, pluralities of fuels, or non-fuel substances added to the combustible mixtures peculiar to engines working with pluralities of fuels, e.g. alternatively with light and heavy fuel oil, other than engines indifferent to the fuel consumed
    • F02D19/0602—Control of components of the fuel supply system
    • F02D19/0607—Control of components of the fuel supply system to adjust the fuel mass or volume flow
    • F02D19/061—Control of components of the fuel supply system to adjust the fuel mass or volume flow by controlling fuel injectors
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
    • F02D—CONTROLLING COMBUSTION ENGINES
    • F02D19/00—Controlling engines characterised by their use of non-liquid fuels, pluralities of fuels, or non-fuel substances added to the combustible mixtures
    • F02D19/06—Controlling engines characterised by their use of non-liquid fuels, pluralities of fuels, or non-fuel substances added to the combustible mixtures peculiar to engines working with pluralities of fuels, e.g. alternatively with light and heavy fuel oil, other than engines indifferent to the fuel consumed
    • F02D19/0663—Details on the fuel supply system, e.g. tanks, valves, pipes, pumps, rails, injectors or mixers
    • F02D19/0686—Injectors
    • F02D19/0689—Injectors for in-cylinder direct injection
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
    • F02D—CONTROLLING COMBUSTION ENGINES
    • F02D19/00—Controlling engines characterised by their use of non-liquid fuels, pluralities of fuels, or non-fuel substances added to the combustible mixtures
    • F02D19/06—Controlling engines characterised by their use of non-liquid fuels, pluralities of fuels, or non-fuel substances added to the combustible mixtures peculiar to engines working with pluralities of fuels, e.g. alternatively with light and heavy fuel oil, other than engines indifferent to the fuel consumed
    • F02D19/08—Controlling engines characterised by their use of non-liquid fuels, pluralities of fuels, or non-fuel substances added to the combustible mixtures peculiar to engines working with pluralities of fuels, e.g. alternatively with light and heavy fuel oil, other than engines indifferent to the fuel consumed simultaneously using pluralities of fuels
    • F02D19/082—Premixed fuels, i.e. emulsions or blends
    • F02D19/084—Blends of gasoline and alcohols, e.g. E85
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
    • F02D—CONTROLLING COMBUSTION ENGINES
    • F02D19/00—Controlling engines characterised by their use of non-liquid fuels, pluralities of fuels, or non-fuel substances added to the combustible mixtures
    • F02D19/06—Controlling engines characterised by their use of non-liquid fuels, pluralities of fuels, or non-fuel substances added to the combustible mixtures peculiar to engines working with pluralities of fuels, e.g. alternatively with light and heavy fuel oil, other than engines indifferent to the fuel consumed
    • F02D19/08—Controlling engines characterised by their use of non-liquid fuels, pluralities of fuels, or non-fuel substances added to the combustible mixtures peculiar to engines working with pluralities of fuels, e.g. alternatively with light and heavy fuel oil, other than engines indifferent to the fuel consumed simultaneously using pluralities of fuels
    • F02D19/082—Premixed fuels, i.e. emulsions or blends
    • F02D19/085—Control based on the fuel type or composition
    • F02D19/087—Control based on the fuel type or composition with determination of densities, viscosities, composition, concentration or mixture ratios of fuels
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
    • F02D—CONTROLLING COMBUSTION ENGINES
    • F02D41/00—Electrical control of supply of combustible mixture or its constituents
    • F02D41/30—Controlling fuel injection
    • F02D41/3094—Controlling fuel injection the fuel injection being effected by at least two different injectors, e.g. one in the intake manifold and one in the cylinder
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
    • F02D—CONTROLLING COMBUSTION ENGINES
    • F02D41/00—Electrical control of supply of combustible mixture or its constituents
    • F02D41/30—Controlling fuel injection
    • F02D41/38—Controlling fuel injection of the high pressure type
    • F02D41/40—Controlling fuel injection of the high pressure type with means for controlling injection timing or duration
    • F02D41/402—Multiple injections
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
    • F02M—SUPPLYING COMBUSTION ENGINES IN GENERAL WITH COMBUSTIBLE MIXTURES OR CONSTITUENTS THEREOF
    • F02M45/00—Fuel-injection apparatus characterised by having a cyclic delivery of specific time/pressure or time/quantity relationship
    • F02M45/02—Fuel-injection apparatus characterised by having a cyclic delivery of specific time/pressure or time/quantity relationship with each cyclic delivery being separated into two or more parts
    • F02M45/04—Fuel-injection apparatus characterised by having a cyclic delivery of specific time/pressure or time/quantity relationship with each cyclic delivery being separated into two or more parts with a small initial part, e.g. initial part for partial load and initial and main part for full load
    • F02M45/08—Injectors peculiar thereto
    • 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
    • F02B23/00—Other engines characterised by special shape or construction of combustion chambers to improve operation
    • F02B23/08—Other engines characterised by special shape or construction of combustion chambers to improve operation with positive ignition
    • F02B23/10—Other engines characterised by special shape or construction of combustion chambers to improve operation with positive ignition with separate admission of air and fuel into cylinder
    • F02B2023/103—Other engines characterised by special shape or construction of combustion chambers to improve operation with positive ignition with separate admission of air and fuel into cylinder the injector having a multi-hole nozzle for generating multiple sprays
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
    • F02D—CONTROLLING COMBUSTION ENGINES
    • F02D41/00—Electrical control of supply of combustible mixture or its constituents
    • F02D41/30—Controlling fuel injection
    • F02D41/38—Controlling fuel injection of the high pressure type
    • F02D41/3809—Common rail control systems
    • F02D2041/3881—Common rail control systems with multiple common rails, e.g. one rail per cylinder bank, or a high pressure rail and a low pressure rail
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
    • F02D—CONTROLLING COMBUSTION ENGINES
    • F02D2200/00—Input parameters for engine control
    • F02D2200/02—Input parameters for engine control the parameters being related to the engine
    • F02D2200/021—Engine temperature
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
    • F02D—CONTROLLING COMBUSTION ENGINES
    • F02D2200/00—Input parameters for engine control
    • F02D2200/02—Input parameters for engine control the parameters being related to the engine
    • F02D2200/06—Fuel or fuel supply system parameters
    • F02D2200/0602—Fuel pressure
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
    • F02D—CONTROLLING COMBUSTION ENGINES
    • F02D2200/00—Input parameters for engine control
    • F02D2200/02—Input parameters for engine control the parameters being related to the engine
    • F02D2200/06—Fuel or fuel supply system parameters
    • F02D2200/0611—Fuel type, fuel composition or fuel quality
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
    • F02D—CONTROLLING COMBUSTION ENGINES
    • F02D2200/00—Input parameters for engine control
    • F02D2200/02—Input parameters for engine control the parameters being related to the engine
    • F02D2200/10—Parameters related to the engine output, e.g. engine torque or engine speed
    • F02D2200/101—Engine speed
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
    • F02D—CONTROLLING COMBUSTION ENGINES
    • F02D2250/00—Engine control related to specific problems or objectives
    • F02D2250/31—Control of the fuel pressure
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
    • F02D—CONTROLLING COMBUSTION ENGINES
    • F02D41/00—Electrical control of supply of combustible mixture or its constituents
    • F02D41/30—Controlling fuel injection
    • F02D41/38—Controlling fuel injection of the high pressure type
    • F02D41/3809—Common rail control systems
    • F02D41/3836—Controlling the fuel pressure
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
    • F02M—SUPPLYING COMBUSTION ENGINES IN GENERAL WITH COMBUSTIBLE MIXTURES OR CONSTITUENTS THEREOF
    • F02M2200/00—Details of fuel-injection apparatus, not otherwise provided for
    • F02M2200/95—Fuel injection apparatus operating on particular fuels, e.g. biodiesel, ethanol, mixed fuels
    • F02M2200/956—Ethanol
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
    • F02M—SUPPLYING COMBUSTION ENGINES IN GENERAL WITH COMBUSTIBLE MIXTURES OR CONSTITUENTS THEREOF
    • F02M51/00—Fuel-injection apparatus characterised by being operated electrically
    • F02M51/06—Injectors peculiar thereto with means directly operating the valve needle
    • F02M51/0603—Injectors peculiar thereto with means directly operating the valve needle using piezoelectric or magnetostrictive operating means
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
    • F02M—SUPPLYING COMBUSTION ENGINES IN GENERAL WITH COMBUSTIBLE MIXTURES OR CONSTITUENTS THEREOF
    • F02M61/00—Fuel-injectors not provided for in groups F02M39/00 - F02M57/00 or F02M67/00
    • F02M61/04—Fuel-injectors not provided for in groups F02M39/00 - F02M57/00 or F02M67/00 having valves, e.g. having a plurality of valves in series
    • F02M61/06—Fuel-injectors not provided for in groups F02M39/00 - F02M57/00 or F02M67/00 having valves, e.g. having a plurality of valves in series the valves being furnished at seated ends with pintle or plug shaped extensions
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
    • F02M—SUPPLYING COMBUSTION ENGINES IN GENERAL WITH COMBUSTIBLE MIXTURES OR CONSTITUENTS THEREOF
    • F02M61/00—Fuel-injectors not provided for in groups F02M39/00 - F02M57/00 or F02M67/00
    • F02M61/04—Fuel-injectors not provided for in groups F02M39/00 - F02M57/00 or F02M67/00 having valves, e.g. having a plurality of valves in series
    • F02M61/08—Fuel-injectors not provided for in groups F02M39/00 - F02M57/00 or F02M67/00 having valves, e.g. having a plurality of valves in series the valves opening in direction of fuel flow
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
    • F02M—SUPPLYING COMBUSTION ENGINES IN GENERAL WITH COMBUSTIBLE MIXTURES OR CONSTITUENTS THEREOF
    • F02M61/00—Fuel-injectors not provided for in groups F02M39/00 - F02M57/00 or F02M67/00
    • F02M61/04—Fuel-injectors not provided for in groups F02M39/00 - F02M57/00 or F02M67/00 having valves, e.g. having a plurality of valves in series
    • F02M61/10—Other injectors with elongated valve bodies, i.e. of needle-valve type
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
    • F02M—SUPPLYING COMBUSTION ENGINES IN GENERAL WITH COMBUSTIBLE MIXTURES OR CONSTITUENTS THEREOF
    • F02M61/00—Fuel-injectors not provided for in groups F02M39/00 - F02M57/00 or F02M67/00
    • F02M61/16—Details not provided for in, or of interest apart from, the apparatus of groups F02M61/02 - F02M61/14
    • F02M61/18—Injection nozzles, e.g. having valve seats; Details of valve member seated ends, not otherwise provided for
    • F02M61/1806—Injection nozzles, e.g. having valve seats; Details of valve member seated ends, not otherwise provided for characterised by the arrangement of discharge orifices, e.g. orientation or size
    • 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
    • Y02T10/12—Improving ICE efficiencies
    • 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
    • Y02T10/30—Use of alternative fuels, e.g. biofuels
    • 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

Landscapes

  • Engineering & Computer Science (AREA)
  • Chemical & Material Sciences (AREA)
  • Combustion & Propulsion (AREA)
  • Mechanical Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Oil, Petroleum & Natural Gas (AREA)
  • Output Control And Ontrol Of Special Type Engine (AREA)
  • Electrical Control Of Air Or Fuel Supplied To Internal-Combustion Engine (AREA)
  • Combined Controls Of Internal Combustion Engines (AREA)
  • Fuel-Injection Apparatus (AREA)

Description

本発明は、内燃機関の燃料噴射制御装置および燃料噴射制御方法に関する。   The present invention relates to a fuel injection control device and a fuel injection control method for an internal combustion engine.

内燃機関の性能を確保するための技術として、例えば、特許文献１に記載されたものがある。この特許文献１には、「アルコール混合燃料が使用される筒内直噴式のエンジンを備える内燃機関であって、前記エンジンに供給される燃料のアルコール濃度に応じて燃料噴射時期が設定されると共に、当該燃料噴射時期を制御量として前記エンジンの燃料噴射制御が行われることを特徴とし、燃料のアルコール濃度が増加すると燃料噴射時期が進角側に設定され、且つ、燃料のアルコール濃度が減少すると燃料噴射時期が遅角側に設定される」と記載されている。   As a technique for ensuring the performance of an internal combustion engine, for example, there is one described in Patent Document 1. This patent document 1 discloses an “internal combustion engine having an in-cylinder direct injection type engine in which alcohol mixed fuel is used, and the fuel injection timing is set according to the alcohol concentration of fuel supplied to the engine. The fuel injection control of the engine is performed using the fuel injection timing as a control amount. When the alcohol concentration of the fuel increases, the fuel injection timing is set to the advance side, and when the alcohol concentration of the fuel decreases. The fuel injection timing is set to the retard side ”.

特開２００９−４７０５５号公報JP 2009-47055 A

ところで、筒内直噴式のエンジンでは、筒内に噴射された燃料がピストン冠面や燃焼室ボア壁面などに付着し、機関温度が低いときには、これら付着燃料によって、粒子状物質（Ｐａｒｔｉｃｕｌａｔｅ Ｍａｔｔｅｒ、ＰＭ）の生成や、潤滑油に燃料が溶解する所謂オイル希釈が発生することが知られている。   By the way, in an in-cylinder direct injection engine, fuel injected into the cylinder adheres to a piston crown surface, a combustion chamber bore wall surface, and the like, and when the engine temperature is low, particulate matter (Particulate Matter, PM ) And so-called oil dilution in which the fuel dissolves in the lubricating oil.

一方、ＣＯ２排出の削減のために、近年の内燃機関ではガソリンとアルコール（主にエタノール）とを混ぜた混合燃料が使われるようになってきている。アルコールの混合比率が様々に変化しても走行可能な車両は、フレックス燃料車（Ｆｌｅｘｉｂｌｅ−Ｆｕｅｌ Ｖｅｈｉｃｌｅ、ＦＦＶ）として知られている。 On the other hand, in order to reduce CO 2 emissions, in recent internal combustion engines, a mixed fuel in which gasoline and alcohol (mainly ethanol) are mixed has been used. A vehicle that can run even when the mixing ratio of alcohol varies is known as a flex-fuel vehicle (FFV).

ここで、冷機運転時におけるＰＭの発生量とオイル希釈の程度は、燃料性状によって変化するため、ＰＭとオイル希釈を同時に低減するには、燃料性状に応じた最適なエンジン制御が必要である。このため、特許文献１に記載の技術では、燃料のアルコール濃度が増加すると、燃料噴射時期を進角側に設定し、且つ、燃料のアルコール濃度が減少すると、燃料噴射時期が遅角側に設定することで対応している。   Here, since the amount of PM generated and the degree of oil dilution during cold operation vary depending on the fuel properties, optimal engine control in accordance with the fuel properties is required to simultaneously reduce PM and oil dilution. For this reason, in the technique described in Patent Document 1, when the alcohol concentration of the fuel increases, the fuel injection timing is set to the advance side, and when the alcohol concentration of the fuel decreases, the fuel injection timing is set to the retard side. It corresponds by doing.

燃料噴射のタイミングは、ＰＭとオイル希釈の原因となる壁面付着量のみでなく、エンジン燃焼室内での燃料と空気の混合にも影響する。特許文献１に記載されたように、アルコール濃度に応じて、燃料噴射時期を進角側に設定、もしくは遅角側に設定する方法では、燃料と空気の混合が不十分となる虞がある。   The timing of fuel injection affects not only the amount of wall surface adhesion that causes PM and oil dilution, but also the mixing of fuel and air in the engine combustion chamber. As described in Patent Document 1, in the method of setting the fuel injection timing to the advance side or the retard side according to the alcohol concentration, there is a possibility that the mixing of fuel and air may be insufficient.

本発明の目的は、燃料と空気の混合を良好に保ちつつ、内燃機関の冷機時におけるＰＭとオイル希釈とを低減可能な内燃機関の燃料噴射制御装置および燃料噴射制御方法を実現することである。   An object of the present invention is to realize a fuel injection control device and a fuel injection control method for an internal combustion engine that can reduce PM and oil dilution when the internal combustion engine is cold while maintaining good mixing of fuel and air. .

上記目的を達成するため、次のように構成される。   In order to achieve the above object, the following structure is provided.

本発明の内燃機関の燃料噴射制御装置は、ガソリンとアルコールとの混合燃料のアルコール濃度を検出するアルコール濃度センサと、内燃機関の温度を検出する温度センサと、上記混合燃料を筒内に噴射する筒内噴射式の燃料噴射弁と、制御部とを備える。 A fuel injection control device for an internal combustion engine according to the present invention includes an alcohol concentration sensor that detects an alcohol concentration of a mixed fuel of gasoline and alcohol, a temperature sensor that detects a temperature of the internal combustion engine , and injects the mixed fuel into a cylinder. An in-cylinder fuel injection valve and a control unit are provided.

制御部は、上記温度センサが検出した温度に従って内燃機関が冷機状態であると判断した場合には、内燃機関の吸気行程を複数の燃料噴射期間に分割し、分割した燃料噴射期間の内の初期の燃料噴射期間の燃料噴射量を、上記アルコール濃度センサが検出したアルコール濃度が高くなるに従って多くし、上記分割した期間の内の後期の燃料噴射期間の燃料噴射量を、上記アルコール濃度センサが検出したアルコール濃度が高くなるに従って少なくして、上記燃料噴射弁が噴射する混合燃料の噴射量を制御する。 When the control unit determines that the internal combustion engine is in the cold state according to the temperature detected by the temperature sensor, the control unit divides the intake stroke of the internal combustion engine into a plurality of fuel injection periods, and the initial of the divided fuel injection periods The fuel injection amount in the fuel injection period is increased as the alcohol concentration detected by the alcohol concentration sensor increases, and the alcohol concentration sensor detects the fuel injection amount in the later fuel injection period in the divided period. The amount of the mixed fuel injected by the fuel injection valve is controlled to decrease as the alcohol concentration increases.

また、本発明の内燃機関の燃料噴射制御方法は、ガソリンとアルコールとの混合燃料のアルコール濃度を検出し、内燃機関の温度を検出する。そして、検出した温度に従って内燃機関が冷機状態であると判断した場合には、内燃機関の吸気行程を複数の燃料噴射期間に分割し、分割した燃料噴射期間の内の初期の燃料噴射期間の燃料噴射量を、上記検出したアルコール濃度が高くなるに従って多くし、上記分割した期間の内の後期の燃料噴射期間の燃料噴射量を、上記検出したアルコール濃度が高くなるに従って少なくして、筒内噴射式の燃料噴射弁が噴射する混合燃料の噴射量を制御する。 In the fuel injection control method for an internal combustion engine according to the present invention, the alcohol concentration of the mixed fuel of gasoline and alcohol is detected to detect the temperature of the internal combustion engine. When it is determined that the internal combustion engine is in a cold state according to the detected temperature , the intake stroke of the internal combustion engine is divided into a plurality of fuel injection periods, and the fuel in the initial fuel injection period among the divided fuel injection periods the injection quantity, and number in accordance with the alcohol concentration of the above-mentioned detection is increased, the fuel injection amount of the late fuel injection period of the period and the divided, and decreases as the alcohol concentration above the detection is high, in-cylinder injection The fuel injection amount of the mixed fuel injected by the fuel injection valve of the type is controlled.

本発明によれば、燃料と空気の混合を良好に保ちつつ、内燃機関の冷機時におけるＰＭとオイル希釈とを低減可能な内燃機関の燃料噴射制御装置および燃料噴射制御方法を実現することができる。   According to the present invention, it is possible to realize a fuel injection control device and a fuel injection control method for an internal combustion engine that can reduce PM and oil dilution when the internal combustion engine is cold while maintaining good mixing of fuel and air. .

本発明の実施例が適用される内燃機関の概略構成図である。1 is a schematic configuration diagram of an internal combustion engine to which an embodiment of the present invention is applied. 本発明の実施例に使用されるアルコール濃度センサの出力例を示したグラフである。It is the graph which showed the example of an output of the alcohol concentration sensor used for the Example of this invention. 本発明の実施例１における内燃機関のシリンダの概略縦断面図である。It is a schematic longitudinal cross-sectional view of the cylinder of the internal combustion engine in Example 1 of this invention. 本発明の実施例１における内燃機関の概略斜視図である。1 is a schematic perspective view of an internal combustion engine in Embodiment 1 of the present invention. 本発明の実施例１における燃料噴射弁のノズルの部分断面図である。It is a fragmentary sectional view of the nozzle of the fuel injection valve in Example 1 of the present invention. 本発明の実施例１における燃料噴射弁のノズルの概略平面図である。It is a schematic plan view of the nozzle of the fuel injection valve in Example 1 of the present invention. 本発明の実施例１における燃料噴射弁の噴射量特性であり、噴射期間（噴射パルス幅）と噴射量との関係を示したグラフである。It is the injection quantity characteristic of the fuel injection valve in Example 1 of this invention, and is the graph which showed the relationship between injection period (injection pulse width) and injection quantity. 本発明の実施例１における燃料噴射弁から噴射される噴霧の形態を示した図である。It is the figure which showed the form of the spray injected from the fuel injection valve in Example 1 of this invention. 本発明の実施例１における燃料噴射弁から噴射される噴霧の横断面を示した図である。It is the figure which showed the cross section of the spray injected from the fuel injection valve in Example 1 of this invention. 内燃機関において、燃料を吸気行程前期に噴射したときの噴霧の挙動例を示した図である。In an internal combustion engine, it is the figure which showed the example of behavior of the spray when fuel is injected in the first half of the intake stroke. 内燃機関において、燃料を吸気行程後期に噴射したときの噴霧の挙動例を示した図である。In an internal combustion engine, it is the figure which showed the example of the behavior of the spray when fuel is injected in the latter half of the intake stroke. 本発明の実施例１におけるエンジン始動後の運転モード切替え手順を示したフローチャートである。It is the flowchart which showed the operation mode switching procedure after the engine start in Example 1 of this invention. 本発明の実施例１におけるＥＣＵ内のエンジン始動後の運転モード切替についての機能ブロックを示す図である。It is a figure which shows the functional block about the operation mode switching after the engine start in ECU in Example 1 of this invention. 本発明の実施例１における噴射時期を示したタイミングチャートである。It is a timing chart which showed the injection timing in Example 1 of this invention. 本発明の実施例１における、アルコール濃度と初段噴射比率の関係の一例を示したグラフである。It is the graph which showed an example of the relationship between alcohol concentration and the first stage injection ratio in Example 1 of this invention. 本発明の実施例１における、アルコール濃度と初段噴射比率の関係の別の一例を示したグラフである。It is the graph which showed another example of the relationship between alcohol concentration and the first stage injection ratio in Example 1 of this invention. 本発明の実施例１における、アルコール濃度が低い場合の、ピストン冠面位置と噴射タイミングとの関係を示した図である。It is the figure which showed the relationship between the piston crown surface position and injection timing in Example 1 of this invention when alcohol concentration is low. 本発明の実施例１における、アルコール濃度が高い場合の、ピストン冠面位置と噴射タイミングとの関係を示した図である。It is the figure in Example 1 of this invention which showed the relationship between a piston crown surface position and injection timing when alcohol concentration is high. 本発明の実施例１における、アルコール濃度に対する燃料のピストン付着量とシリンダボア付着量の変化を示したグラフである。It is the graph which showed the change of the piston adhesion amount of a fuel with respect to alcohol concentration, and the cylinder bore adhesion amount in Example 1 of this invention. 本発明の実施例１の効果を示し、アルコール濃度に対するＰＭ排出量、オイル希釈率の変化を示すグラフである。It is a graph which shows the effect of Example 1 of this invention, and shows the change of PM discharge | emission amount with respect to alcohol concentration, and an oil dilution rate. 分割噴射と１回噴射における筒内混合気均質性の履歴の一例を示したグラフである。It is the graph which showed an example of the log | history of the in-cylinder mixture homogeneity in a division | segmentation injection and one injection. 分割噴射と１回噴射における筒内当量比の履歴の一例を示したグラフである。It is the graph which showed an example of the log | history of the in-cylinder equivalence ratio in split injection and single injection. アルコール濃度が低い場合の、分割噴射における筒内混合気均質性の履歴の一例を示したグラフである。It is the graph which showed an example of the log | history of the in-cylinder mixture homogeneity in division | segmentation injection in case alcohol concentration is low. アルコール濃度が低い場合の、分割噴射における筒内等量比の履歴の一例を示したグラフである。It is the graph which showed an example of the history of in-cylinder equivalence ratio in divided injection when alcohol concentration is low. アルコール濃度が高い場合の、分割噴射における筒内混合気均質性の履歴の一例を示したグラフである。It is the graph which showed an example of the log | history of the in-cylinder mixture homogeneity in division | segmentation injection in case alcohol concentration is high. アルコール濃度が高い場合の、分割噴射における筒内等量比の履歴の一例を示したグラフである。It is the graph which showed an example of the log | history of the cylinder equivalence ratio in division | segmentation injection when alcohol concentration is high. 本発明の実施例１における、噴射時期の別の一例を示したタイミングチャートである。It is the timing chart which showed another example of the injection timing in Example 1 of this invention. 本発明の実施例１における、噴射時期の別の一例を示したタイミングチャートである。It is the timing chart which showed another example of the injection timing in Example 1 of this invention. 本発明において、アルコール濃度と初段噴射比率の関係を、機関回転速度に対して変化させる例を示したグラフである。In this invention, it is the graph which showed the example which changes the relationship between alcohol concentration and first stage injection ratio with respect to engine speed. 本発明において、アルコール濃度と初段噴射比率の関係を、燃料の噴射圧に対して変化させる例を示したグラフである。In this invention, it is the graph which showed the example which changes the relationship between alcohol concentration and a first stage injection ratio with respect to the injection pressure of a fuel. 本発明において、初段噴射率の上限値、下限値に制限を設ける例を示したグラフである。In this invention, it is the graph which showed the example which provides a restriction | limiting in the upper limit of a first stage injection rate, and a lower limit. 本発明において、最小噴射パルス幅Ｔｍｉｎを示すための、噴射パルス幅と噴射量の関係の例を示したグラフである。In this invention, it is the graph which showed the example of the relationship between the injection pulse width and the injection quantity for showing the minimum injection pulse width Tmin. 本発明の実施例１における、要求噴射量による噴射制御の切り換えを説明するための、噴射時期のタイミングチャートである。It is a timing chart of the injection timing for demonstrating switching of the injection control by the request | requirement injection quantity in Example 1 of this invention. 本発明の実施例２における燃料噴射弁の縦断面図である。It is a longitudinal cross-sectional view of the fuel injection valve in Example 2 of this invention. 本発明の実施例２における燃料噴射弁のノズルの部分断面図である。It is a fragmentary sectional view of the nozzle of the fuel injection valve in Example 2 of the present invention. 本発明の実施例２における燃料噴射弁の弁体リフト履歴の例を示す図である。It is a figure which shows the example of the valve body lift log | history of the fuel injection valve in Example 2 of this invention. 本発明の実施例２における燃料噴射弁の弁リフト高さと噴射量の関係を示すグラフである。It is a graph which shows the relationship between the valve lift height of the fuel injection valve in Example 2 of this invention, and the injection quantity. 本発明の実施例２における、弁リフト時期を示したタイミングチャートである。It is a timing chart which showed valve lift time in Example 2 of the present invention. 本発明の実施例２における、アルコール濃度と初段噴射の弁リフト比の関係の一例を示したグラフである。It is the graph which showed an example of the relationship between the alcohol concentration and the valve lift ratio of the first stage injection in Example 2 of the present invention. 本発明の実施例２における、アルコール濃度と初段噴射の弁リフト比の関係の別の一例を示したグラフである。It is the graph which showed another example of the relationship between the alcohol concentration and the valve lift ratio of the first stage injection in Example 2 of the present invention. 本発明の実施例３における内燃機関の概略構成図である。It is a schematic block diagram of the internal combustion engine in Example 3 of this invention. 本発明の実施例３における燃料噴射弁と燃料噴射弁から噴射される噴霧のザウター平均粒径と噴射圧の関係を示すグラフである。It is a graph which shows the relationship between the fuel injection valve in Example 3 of this invention, the Sauter average particle diameter of the spray injected from a fuel injection valve, and injection pressure. 本発明の実施例３における噴射時期を示したタイミングチャートである。It is a timing chart which showed the injection timing in Example 3 of this invention. 本発明の実施例３におけるアルコール濃度と噴射圧の関係を示したグラフである。It is the graph which showed the relationship between the alcohol concentration and injection pressure in Example 3 of this invention. 本発明の実施例３における、噴射時期を示したタイミングチャートである。It is a timing chart which showed the injection timing in Example 3 of this invention. 本発明が適用される直上噴射式筒内噴射エンジンの構成図である。It is a lineblock diagram of the direct injection type in-cylinder injection engine to which the present invention is applied. 直上噴射式筒内噴射エンジンにおいて、吸気行程前期に燃料を噴射したときの噴霧挙動の例を示した図である。FIG. 5 is a diagram showing an example of spray behavior when fuel is injected in the first half of the intake stroke in a direct injection type in-cylinder injection engine. 直上噴射式筒内噴射エンジンにおいて、吸気行程後期に燃料を噴射したときの噴霧挙動の例を示した図である。In a direct injection type in-cylinder injection engine, it is a figure showing an example of spray behavior when fuel is injected in the latter half of the intake stroke.

以下、添付図面を用いて本発明の実施例について説明する。   Embodiments of the present invention will be described below with reference to the accompanying drawings.

（実施例１）
図１は、本発明の実施例１が適用される内燃機関における制御系の概略構成図である。図１において、内燃機関１は、シリンダヘッドに燃料噴射弁（インジェクタ）１０６と点火プラグ１０７とを備えた筒内噴射式点火機関である。内燃機関１は、ガソリンとアルコールの混合燃料を使用し、任意のアルコール濃度で運転可能なように内燃機関の構成部品やエンジン仕様、制御仕様が決められている。 Example 1
FIG. 1 is a schematic configuration diagram of a control system in an internal combustion engine to which Embodiment 1 of the present invention is applied. In FIG. 1, an internal combustion engine 1 is a cylinder injection type ignition engine having a fuel injection valve (injector) 106 and a spark plug 107 in a cylinder head. The internal combustion engine 1 uses a mixed fuel of gasoline and alcohol, and the components, engine specifications, and control specifications of the internal combustion engine are determined so that it can be operated at an arbitrary alcohol concentration.

燃料タンク３内には、ガソリンとアルコールの混合燃料６が充填されている。混合燃料６のアルコール濃度は固定されたものではなく、ユーザーが補給する燃料仕様、補給時のタンク３内の残存燃料の仕様、残存量などによって０〜１００％の範囲で変化する。   The fuel tank 3 is filled with a mixed fuel 6 of gasoline and alcohol. The alcohol concentration of the mixed fuel 6 is not fixed, but varies in the range of 0 to 100% depending on the fuel specification supplied by the user, the specification of the remaining fuel in the tank 3 at the time of supply, the remaining amount, and the like.

燃料タンク３内の混合燃料６はフィードポンプ５によって３００ｋＰａ程度に加圧され、燃料配管７ａを通って高圧燃料ポンプ２に送られる。混合燃料は高圧燃料ポンプ２によって更に５〜２０ＭＰａ程度に加圧され、高圧燃料配管７ｂを通って燃料噴射弁１０６に送られる。高圧燃料配管７ｂ内の燃料圧力（噴射圧）は噴射圧力センサ９によって検出され、噴射圧信号Ｓ５がＥＣＵ（制御部）１１２に取り込まれる。ＥＣＵ１１２は、噴射圧信号Ｓ５をフィードバックしながら高圧燃料ポンプ２に送る噴射圧指令値Ｓ２を調整することで高圧燃料配管７ｂ内の噴射圧が所定目標値に設定される。   The mixed fuel 6 in the fuel tank 3 is pressurized to about 300 kPa by the feed pump 5 and sent to the high-pressure fuel pump 2 through the fuel pipe 7a. The mixed fuel is further pressurized to about 5 to 20 MPa by the high pressure fuel pump 2 and sent to the fuel injection valve 106 through the high pressure fuel pipe 7b. The fuel pressure (injection pressure) in the high-pressure fuel pipe 7b is detected by the injection pressure sensor 9, and the injection pressure signal S5 is taken into the ECU (control unit) 112. The ECU 112 adjusts the injection pressure command value S2 sent to the high pressure fuel pump 2 while feeding back the injection pressure signal S5, thereby setting the injection pressure in the high pressure fuel pipe 7b to a predetermined target value.

混合燃料のアルコール濃度は燃料タンク３内に設けたアルコール濃度センサ４によって検出される。アルコール濃度センサ４によって検出されたアルコール濃度信号Ｓ１がＥＣＵ１１２に取り込まれる。   The alcohol concentration of the mixed fuel is detected by an alcohol concentration sensor 4 provided in the fuel tank 3. The alcohol concentration signal S1 detected by the alcohol concentration sensor 4 is taken into the ECU 112.

アルコール濃度センサ４は燃料の誘電率、もしくは光の屈折率からアルコール濃度を検出し、電圧値として出力するものである。   The alcohol concentration sensor 4 detects the alcohol concentration from the dielectric constant of fuel or the refractive index of light and outputs it as a voltage value.

図２に燃料のアルコール濃度に対するアルコール濃度センサ４の出力電圧の変化の一例を示す。アルコール濃度センサ４の出力電圧はアルコール濃度と１対１の相関があり、アルコール濃度センサ４の出力電圧値から図２の相関を用いて燃料のアルコール濃度を求めることができる。   FIG. 2 shows an example of the change in the output voltage of the alcohol concentration sensor 4 with respect to the alcohol concentration of the fuel. The output voltage of the alcohol concentration sensor 4 has a one-to-one correlation with the alcohol concentration, and the alcohol concentration of the fuel can be obtained from the output voltage value of the alcohol concentration sensor 4 using the correlation of FIG.

図１において、ＥＣＵ１１２から燃料噴射弁１０６に噴射信号Ｓ３を送ることで、所定のタイミング、期間で燃料噴射弁１０６から内燃機関１の燃焼室内へ燃料が噴射される。また、ＥＣＵ１１２から点火プラグ１０７に点火信号Ｓ４を送ることで、所定のタイミングにおいて、燃焼室内の混合気が点火プラグ１０７によって点火される。   In FIG. 1, by sending an injection signal S3 from the ECU 112 to the fuel injection valve 106, fuel is injected from the fuel injection valve 106 into the combustion chamber of the internal combustion engine 1 at a predetermined timing and period. Further, by sending an ignition signal S4 from the ECU 112 to the ignition plug 107, the air-fuel mixture in the combustion chamber is ignited by the ignition plug 107 at a predetermined timing.

内燃機関１の吸気ポート１０９内には燃焼室内へ吸入する空気の量を調整するためのスロットル弁１０が設けられている。スロットル弁１０の開度はＥＣＵ１１２からスロットル弁１０に送られるスロットル弁開度信号Ｓ６により所定の開度に設定される。   A throttle valve 10 for adjusting the amount of air taken into the combustion chamber is provided in the intake port 109 of the internal combustion engine 1. The opening of the throttle valve 10 is set to a predetermined opening by a throttle valve opening signal S6 sent from the ECU 112 to the throttle valve 10.

内燃機関１のシリンダは、図示しない冷却水によって冷却されており、その水温は冷却水温センサ１１によって検出され、冷却水温信号Ｓ７がＥＣＵ１１２に送られる。   The cylinder of the internal combustion engine 1 is cooled by cooling water (not shown), the water temperature is detected by the cooling water temperature sensor 11, and a cooling water temperature signal S7 is sent to the ECU 112.

更にＥＣＵ１１２には、クランク角信号、アクセル開度信号、トランスミッションのギアポジション信号等の信号Ｓ８が取り込まれ、内燃機関１の回転数、負荷（トルク）の検出、冷機／暖機状態の識別等、機関運転状態の種々の判定がＥＣＵ１１２によって行われる。   Further, the ECU 112 receives signals S8 such as a crank angle signal, an accelerator opening signal, a transmission gear position signal, etc., and detects the number of revolutions of the internal combustion engine 1, a load (torque), identification of a cold / warm-up state, etc. Various determinations of the engine operating state are made by the ECU 112.

次に、図３、図４を参照して、内燃機関１のシリンダの構成を説明する。図３は本発明の実施例１が適用される筒内噴射エンジンの中央断面図であり、図４は筒内噴射エンジンの概略斜視図である。   Next, the configuration of the cylinder of the internal combustion engine 1 will be described with reference to FIGS. 3 and 4. FIG. 3 is a central sectional view of a direct injection engine to which the first embodiment of the present invention is applied, and FIG. 4 is a schematic perspective view of the direct injection engine.

図３、図４において、シリンダヘッド１５と、シリンダブロック１６と、シリンダブロック１６に挿入されたピストン１２とにより燃焼室が形成され、燃焼室の中心上部に点火プラグ１０７が設けられている。燃焼室に吸気管１０９と排気管１１０とがそれぞれ開口しており、吸気管１０９の開口部を開閉する吸気弁１３と、排気管１１０の開口部を開閉する排気弁１４が設けられている。シリンダヘッド１５の上部側方部には、燃焼室に直接燃料が噴射できるように燃料噴射弁１０６が設けられている。   3 and 4, a combustion chamber is formed by the cylinder head 15, the cylinder block 16, and the piston 12 inserted into the cylinder block 16, and a spark plug 107 is provided at the upper center of the combustion chamber. An intake pipe 109 and an exhaust pipe 110 are opened in the combustion chamber, and an intake valve 13 for opening and closing the opening of the intake pipe 109 and an exhaust valve 14 for opening and closing the opening of the exhaust pipe 110 are provided. A fuel injection valve 106 is provided on the upper side portion of the cylinder head 15 so that fuel can be directly injected into the combustion chamber.

燃料噴射弁１０６は，概ね５〜２０ＭＰａに加圧された燃料を燃料噴射弁１０６のノズル先端に設けた微細な孔から高速に噴出することで微粒化した燃料を燃焼室に噴射するものである。燃料噴射弁１０６はＥＣＵ１１２からの指令を受けて任意のタイミングと時間幅で燃料を噴射することができる。 The fuel injection valve 106 injects atomized fuel into the combustion chamber by injecting fuel pressurized to approximately 5 to 20 MPa at high speed from a fine hole provided at the nozzle tip of the fuel injection valve 106. . The fuel injection valve 106 can inject fuel at an arbitrary timing and time width upon receiving a command from the ECU 112.

図５は燃料噴射弁１０６のノズル部の中央断面図であり、図６は燃料噴射弁１０６のノズル部を下から見たときの平面図である。また、図７は燃料噴射弁１０６の噴射期間と噴射量との関係を示すグラフであり、図８、図９は燃料噴射弁１０６から噴射される噴霧形状の例を示す図である。   5 is a central sectional view of the nozzle portion of the fuel injection valve 106, and FIG. 6 is a plan view of the nozzle portion of the fuel injection valve 106 as viewed from below. FIG. 7 is a graph showing the relationship between the injection period of the fuel injection valve 106 and the injection amount, and FIGS. 8 and 9 are diagrams showing examples of spray shapes injected from the fuel injection valve 106.

図５及び図６に示されるように、燃料噴射弁１０６のノズル先端には円周上に複数の微細な噴口２１が設けられている。噴口２１の数は例えば６個であり、直径は例えば２００μｍである。この微細な噴口２１から，高圧（例えば５〜２０ＭＰａ）に加圧された燃料を噴射することで、ザウター平均粒径が５〜３０μｍ程度の液滴から構成される噴霧を形成する。燃料の噴射開始、噴射終了は、ノズル内の弁体２０を図示しない電磁石（ソレノイド）、圧電（ピエゾ）素子、磁歪素子等で上下に駆動することで行われる。   As shown in FIGS. 5 and 6, a plurality of fine nozzle holes 21 are provided on the circumference of the nozzle tip of the fuel injection valve 106. The number of the nozzle holes 21 is, for example, six, and the diameter is, for example, 200 μm. By spraying fuel pressurized to a high pressure (for example, 5 to 20 MPa) from the fine nozzle 21, a spray composed of droplets having a Sauter average particle size of about 5 to 30 μm is formed. The start and end of fuel injection are performed by driving the valve body 20 in the nozzle up and down by an electromagnet (solenoid), a piezoelectric (piezo) element, a magnetostrictive element or the like (not shown).

図７は上述したように、噴射期間と噴射量との関係の一例を示している。ここで、噴射期間はＥＣＵ１１２から燃料噴射弁１０６に送られる噴射パルス幅に等しい。噴射期間と噴射量とにはほぼ比例関係があり、噴射期間によって噴射量を調整することができる。 FIG. 7 shows an example of the relationship between the injection period and the injection amount as described above. Here, the injection period is equal to the injection pulse width sent from the ECU 112 to the fuel injection valve 106. There is a substantially proportional relationship between the injection period and the injection amount, and the injection amount can be adjusted by the injection period.

図８は静止大気中に噴射した時の噴霧外観形状の一例を示しており、図９は図８のＡＡ線に沿った断面位置での噴霧形状を示している。前述したように、燃料噴射弁１０６の先端には円周上に複数の噴口２１が設けられており、各噴口２１から例えば１０ａ〜１０ｆで示されるような噴霧が形成される。   FIG. 8 shows an example of the appearance of the spray when it is injected into still air, and FIG. 9 shows the spray at the cross-sectional position along the line AA in FIG. As described above, a plurality of injection holes 21 are provided on the circumference of the tip of the fuel injection valve 106, and sprays such as those indicated by 10 a to 10 f are formed from the injection holes 21.

次に、図１０及び図１１を用いて、本発明の実施例１における内燃機関の燃焼室内に噴射された噴霧挙動について説明する。   Next, the behavior of the spray injected into the combustion chamber of the internal combustion engine in the first embodiment of the present invention will be described with reference to FIGS.

図１０は燃料噴射開始タイミングが吸気行程の前期、例えば吸気上死点後３０ｄｅｇＣＡの場合の噴霧挙動を示す図である。吸気行程の前期ではピストン１２は高い位置（上死点に近い位置）にあるため、噴霧１０ａ〜１０ｆの殆どは、ピストン１２の冠面に衝突する。内燃機関が冷機状態のときは、ピストン１２の冠面の温度が低いため、冠面に衝突した液滴の多くは、ピストン１２の冠面上に液膜を形成する。   FIG. 10 is a diagram showing the spray behavior when the fuel injection start timing is in the first half of the intake stroke, for example, 30 deg CA after the intake top dead center. Since the piston 12 is at a high position (position close to top dead center) in the first half of the intake stroke, most of the sprays 10a to 10f collide with the crown surface of the piston 12. When the internal combustion engine is in a cold state, the temperature of the crown surface of the piston 12 is low, so that most of the droplets that collide with the crown surface form a liquid film on the crown surface of the piston 12.

図１１は燃料噴射終了タイミングが吸気行程の後期、例えば吸気上死点後１２０ｄｅｇＣＡの場合の噴霧挙動を示す図である。吸気行程の後期ではピストン１２は低い位置（上死点から離れた位置）にあるため、噴霧の一部が燃焼室ボア壁面に衝突し、噴霧の他の一部は、ピストン１２の冠面に衝突する。内燃機関が冷機状態のときは、燃焼室ボア壁面の温度が低いため、燃焼室ボア壁面に衝突した液滴の多くは、燃焼室ボア壁面上に液膜を形成する。また、ピストン１２に衝突した液滴も同様にピストン１２の冠面上に液膜を形成する。   FIG. 11 is a diagram showing the spray behavior when the fuel injection end timing is in the later stage of the intake stroke, for example, 120 deg CA after the intake top dead center. In the latter stage of the intake stroke, the piston 12 is in a low position (a position away from the top dead center), so that a part of the spray collides with the combustion chamber bore wall surface and the other part of the spray hits the crown surface of the piston 12. collide. When the internal combustion engine is in a cold state, the temperature of the combustion chamber bore wall surface is low, so that many of the droplets that collide with the combustion chamber bore wall surface form a liquid film on the combustion chamber bore wall surface. Similarly, the liquid droplet that collided with the piston 12 forms a liquid film on the crown surface of the piston 12.

次に、本発明の実施例１におけるエンジン始動後の運転モード切替フローを図１２、図１３を参照して説明する。図１２は、エンジン始動後の運転モード切替の動作フローを示す図であり、図１３はＥＣＵ１１２内のエンジン始動後の運転モード切替についての機能ブロックを示す図である。   Next, the operation mode switching flow after engine start in Embodiment 1 of the present invention will be described with reference to FIGS. FIG. 12 is a diagram showing an operation flow of operation mode switching after engine startup, and FIG. 13 is a functional block diagram for operation mode switching after engine startup in ECU 112.

図１２、図１３において、エンジン始動後（ステップＳ１）、ＥＣＵ１１２のアルコール濃度判断部１１２ａはアルコール濃度センサ４の検出信号Ｓ１により燃料タンク３内の燃料のアルコール濃度Ｘｅを判断（算出）する（ステップＳ２）。次に、ＥＣＵ１１２の冷機状態判断部１１２ｂは冷却水温センサ１１の検出信号Ｓ７により冷却水温Ｔｗを取得し（ステップＳ３）、予め設定された温度閾値Ｔｗｃ（例えば５０°Ｃ）とＴｗとを比較する（ステップＳ４）。冷機状態判断部１１２ｂは冷却水温ＴｗがＴｗｃより低い場合には内燃機関は冷機状態と判断し、冷機状態であることを燃料噴射制御部１１２ｄに伝達する。燃料噴射制御部１１２ｄは、メモリ１１２ｃに格納されたアルコール濃度と燃料噴射期間との関係を示すデータと、アクセル開度等を示す信号Ｓ８とに基づいてインジェクタ１０６等に指令信号を送り、冷機モードでの機関運転の制御を実施する（ステップＳ５）。   12 and 13, after the engine is started (step S1), the alcohol concentration determination unit 112a of the ECU 112 determines (calculates) the alcohol concentration Xe of the fuel in the fuel tank 3 based on the detection signal S1 of the alcohol concentration sensor 4 (step S1). S2). Next, the cold state determination unit 112b of the ECU 112 acquires the coolant temperature Tw from the detection signal S7 of the coolant temperature sensor 11 (step S3), and compares a preset temperature threshold value Twc (for example, 50 ° C.) with Tw. (Step S4). When the cooling water temperature Tw is lower than Twc, the cold machine state determination unit 112b determines that the internal combustion engine is in the cold state, and transmits the fact that it is in the cold state to the fuel injection control unit 112d. The fuel injection control unit 112d sends a command signal to the injector 106 or the like based on the data indicating the relationship between the alcohol concentration stored in the memory 112c and the fuel injection period, and the signal S8 indicating the accelerator opening, etc. The engine operation is controlled at (Step S5).

ステップＳ４において、冷機状態判断部１１２ｂは冷却水温ＴｗがＴｗｃより以上の場合には内燃機関は暖機状態と判断し、暖機状態であることを燃料噴射制御部１１２ｄに伝達する。燃料噴射制御部１１２ｄは、アクセル開度等を示す信号Ｓ８に基づいて燃料噴射弁（インジェクタ）１０６等に指令信号を送り、暖機モードでの機関運転の制御を実施する（ステップＳ６）。   In step S4, when the cooling water temperature Tw is equal to or higher than Twc, the cold state determination unit 112b determines that the internal combustion engine is in a warm state, and notifies the fuel injection control unit 112d that the internal combustion engine is in a warm state. The fuel injection control unit 112d sends a command signal to the fuel injection valve (injector) 106 and the like based on the signal S8 indicating the accelerator opening, etc., and controls the engine operation in the warm-up mode (step S6).

冷機モードは冷却水温ＴｗがＴｗｃに到達するまで継続し、Ｔｗ≧Ｔｗｃになったら、冷機モードから暖機モードに移行する。   The cool-down mode is continued until the coolant temperature Tw reaches Twc, and when Tw ≧ Twc, the cool-down mode is shifted to the warm-up mode.

次に、本発明の実施例１による、冷機モードにおける燃料噴射の制御方法について説明する。   Next, a fuel injection control method in the cold machine mode according to the first embodiment of the present invention will be described.

図１４は、本発明の実施例１による冷機モードにおける燃料の噴射タイミングのチャートを示す図である。図１４において、冷機モードでは、燃料は吸気行程内に２回に分割して噴射する。ここで、２回に分割した前側の燃料噴射期間を初段噴射（初期の燃料噴射期間）とし、その噴射期間（噴射パルス幅）をＴ１と定義する。また２回に分割した後側の燃料噴射期間を終段噴射（後期の燃料噴射期間）とし、その噴射期間（噴射パルス幅）をＴ２と定義する。   FIG. 14 is a chart showing a fuel injection timing chart in the cold machine mode according to the first embodiment of the present invention. In FIG. 14, in the cold machine mode, the fuel is divided and injected twice in the intake stroke. Here, the front side fuel injection period divided into two times is defined as first stage injection (initial fuel injection period), and the injection period (injection pulse width) is defined as T1. Further, the rear fuel injection period divided into two times is defined as final stage injection (late fuel injection period), and the injection period (injection pulse width) is defined as T2.

初段噴射は吸気行程の前期に実施され、その噴射開始時期は例えば吸気上死点後３０ｄｅｇＣＡである。一方、終段噴射は吸気行程の後期に実施され、その噴射終了時期は例えば１２０ｄｅｇＣＡである。   The first stage injection is performed in the first half of the intake stroke, and the injection start timing is, for example, 30 deg CA after the intake top dead center. On the other hand, the final stage injection is performed later in the intake stroke, and the injection end timing is, for example, 120 degCA.

図１４に示すように、本発明の実施例１では、アルコール濃度を低（例えば、０〜３３％）、中（３４〜６６％）、高（６７〜１００％）に分割し、噴射期間Ｔ１とＴ２の長さを燃料のアルコール濃度によって変化させ、アルコール濃度が高いほど、Ｔ１を長く、Ｔ２を短く設定する。即ちアルコール濃度が高いほど、初段噴射の噴射量比率を高く、終段噴射の噴射量比率を低く設定する。   As shown in FIG. 14, in Example 1 of the present invention, the alcohol concentration is divided into low (for example, 0 to 33%), medium (34 to 66%), and high (67 to 100%), and the injection period T1. The length of T2 is changed according to the alcohol concentration of the fuel, and as the alcohol concentration is higher, T1 is set longer and T2 is set shorter. That is, the higher the alcohol concentration, the higher the injection amount ratio of the first-stage injection and the lower the injection amount ratio of the final-stage injection.

例えば、アルコール濃度が低では、噴射期間Ｔ１とＴ２との比を１対３、アルコール濃度が中は、噴射期間Ｔ１とＴ２との比を１対１、アルコール濃度が高では、噴射期間Ｔ１とＴ２との比を３対１とする。   For example, when the alcohol concentration is low, the ratio between the injection periods T1 and T2 is 1: 3. When the alcohol concentration is medium, the ratio between the injection periods T1 and T2 is 1: 1. When the alcohol concentration is high, the ratio is the injection period T1. The ratio with T2 is 3: 1.

なお、図１５に示すように、アルコール濃度の増加に対して、初段噴射の比率Ｔ１／（Ｔ１＋Ｔ２）を連続的に増やしても良い。また、図１６に示すように、アルコール濃度の増加に対して、初段噴射の比率Ｔ１／（Ｔ１＋Ｔ２）を段階的に増やしても良い。   As shown in FIG. 15, the first-stage injection ratio T1 / (T1 + T2) may be continuously increased with respect to the increase in alcohol concentration. Further, as shown in FIG. 16, the ratio T1 / (T1 + T2) of the first stage injection may be increased stepwise as the alcohol concentration increases.

噴射時期Ｔ１とＴ２との間の空白期間は、使用するエンジン仕様等により、決定することができる。   The blank period between the injection timings T1 and T2 can be determined according to the engine specifications used.

ここで、吸気行程の前期と後期との２つに分割して、燃料を噴射する構成とせずに、吸気行程の前期又は後期に燃料を噴射せず、後期又は前期に連続して燃料を噴射することも考えられるが、後述するように、混合気均質性の観点から、吸気行程期間を分割して、燃料を噴射する構成としている。   Here, the fuel is not injected in the first or second half of the intake stroke without being divided into two parts, the first and second half of the intake stroke, and the fuel is injected continuously in the second or first half of the intake stroke. However, as will be described later, from the viewpoint of air-fuel mixture homogeneity, the intake stroke period is divided and fuel is injected.

図１７、図１８は、冷機モードにおける燃料噴射タイミングとピストン１２の冠面位置との関係を示す図である。図１７は、アルコール濃度が低い場合の燃料噴射タイミングとピストン１２の冠面位置との関係を示しており、図１８は、アルコール濃度が高い場合の燃料噴射タイミングとピストン１２の冠面位置との関係を示している。   17 and 18 are diagrams showing the relationship between the fuel injection timing in the cold machine mode and the crown surface position of the piston 12. FIG. 17 shows the relationship between the fuel injection timing when the alcohol concentration is low and the crown surface position of the piston 12, and FIG. 18 shows the relationship between the fuel injection timing and the crown surface position of the piston 12 when the alcohol concentration is high. Showing the relationship.

図１７、図１８において、ピストン１２の冠面位置は、吸気上死点で最も高く（シリンダヘッドに近く）、吸気下死点に向けて低くなっていく。   17 and 18, the crown surface position of the piston 12 is the highest at the intake top dead center (close to the cylinder head) and decreases toward the intake bottom dead center.

初段噴射の噴射時期ではピストン１２の冠面位置は高いため、初段噴射で噴射された燃料は図１０に示したように、多くがピストン１２の冠面に衝突、付着する。このため、初段噴射の燃料は、シリンダボア壁には殆ど付着しない。   Since the crown surface position of the piston 12 is high at the injection timing of the first stage injection, most of the fuel injected by the first stage injection collides with and adheres to the crown surface of the piston 12 as shown in FIG. For this reason, the fuel of the first stage injection hardly adheres to the cylinder bore wall.

一方、終段噴射の噴射時期ではピストン１２の冠面位置は低いため、終段噴射で噴射された燃料の一部が図１１に示したように、ピストン１２の冠面とシリンダボア壁に衝突し、付着する。   On the other hand, since the crown surface position of the piston 12 is low at the injection timing of the final injection, a part of the fuel injected by the final injection collides with the crown surface of the piston 12 and the cylinder bore wall as shown in FIG. ,Adhere to.

本発明の実施例１による噴射制御においては、アルコール濃度が低い場合には、図１７に示すように、ピストン１２の位置が高い時期に噴射される初段噴射量が少なく、ピストン１２の位置が低い時期に噴射される終段噴射量が多くなるように噴射量が設定される。   In the injection control according to the first embodiment of the present invention, when the alcohol concentration is low, as shown in FIG. 17, the first-stage injection amount injected when the position of the piston 12 is high is small and the position of the piston 12 is low. The injection amount is set so that the final injection amount injected at the time increases.

一方、本発明の実施例１による噴射制御においては、アルコール濃度が高い場合には、図１８に示すように、ピストン１２の位置が高い時期に噴射される初段噴射量が多く、ピストン１２の位置が低い時期に噴射される終段噴射量が少なくなるように噴射量が設定される。このため、図１９に示すように、アルコール濃度が低い場合には、ピストン冠面への燃料付着が少なく、シリンダボア壁面への付着が多くなる。一方、アルコール濃度が高い場合には、ピストン１２の冠面への燃料付着が多く、シリンダボア壁面への付着が少なくなる。   On the other hand, in the injection control according to the first embodiment of the present invention, when the alcohol concentration is high, as shown in FIG. 18, the first-stage injection amount injected when the position of the piston 12 is high is large, and the position of the piston 12 The injection amount is set so that the final injection amount injected at a low time becomes small. For this reason, as shown in FIG. 19, when the alcohol concentration is low, the amount of fuel adhering to the piston crown surface is small and the amount of adhering to the cylinder bore wall surface is increased. On the other hand, when the alcohol concentration is high, the fuel adheres to the crown surface of the piston 12 more and adheres to the cylinder bore wall surface.

ガソリンは一般に芳香族炭化水素の成分を多く含んでいる。芳香族炭化水素はＰＭの発生要因物質の１つであり、芳香族炭化水素が多いとＰＭ発生量が多くなる事が知られている。従って、ガソリンがピストン１２の冠面に付着するとＰＭが発生しやすい。一方、ガソリンは低温での気化性が良いため、シリンダボア壁へ付着しても比較的短時間に気化して、潤滑オイルへの溶解はし難い。   Gasoline generally contains many aromatic hydrocarbon components. Aromatic hydrocarbons are one of the factors that generate PM, and it is known that the amount of PM generated increases when there are many aromatic hydrocarbons. Therefore, when gasoline adheres to the crown surface of the piston 12, PM is likely to be generated. On the other hand, since gasoline has good vaporization properties at low temperatures, even if it adheres to the cylinder bore wall, it vaporizes in a relatively short time and is difficult to dissolve in lubricating oil.

従って、アルコール濃度が低い（ガソリン濃度が高い）燃料では、ピストン１２の冠面への燃料付着を少なくすることでＰＭを低く抑えることができる。また、アルコール濃度が低い燃料では、シリンダボア壁面への燃料付着が多くてもオイル希釈は起こり難い。   Therefore, in fuel with low alcohol concentration (high gasoline concentration), PM can be suppressed low by reducing fuel adhesion to the crown surface of the piston 12. In addition, in a fuel with a low alcohol concentration, oil dilution is unlikely to occur even if the fuel adheres to the cylinder bore wall surface.

これに対して、アルコールは芳香族炭化水素の成分を殆ど含んでいないため、ピストン１２の冠面に付着してもＰＭは発生しにくい。   On the other hand, since alcohol contains almost no aromatic hydrocarbon component, PM hardly occurs even if it adheres to the crown surface of the piston 12.

一方、アルコールは低温での気化性がガソリンに比べて低いため、シリンダボア壁へ付着すると気化し難く、オイルへ溶解し易い。従って、アルコール濃度が高い燃料では、シリンダボア壁面への燃料付着を少なくすることで、オイル希釈を低減できる。また、アルコール濃度が高い燃料では、ピストン１２の冠面への燃料付着が多くてもＰＭの発生量は少ない。

On the other hand, since alcohol has a lower vaporization property at a low temperature than gasoline, if it adheres to the cylinder bore wall, it is difficult to vaporize and easily dissolves in oil. Therefore, in a fuel having a high alcohol concentration, oil dilution can be reduced by reducing fuel adhesion to the cylinder bore wall surface. In addition, when the fuel has a high alcohol concentration, the amount of PM generated is small even if the amount of fuel adhering to the crown surface of the piston 12 is large.

本発明による実施例１の燃料噴射制御によって、アルコール濃度が低い場合には、ピストン１２の冠面への燃料付着が少なく、シリンダボア壁面への付着が多くなり、アルコール濃度が高い場合には、ピストン１２の冠面への燃料付着が多く、シリンダボア壁面への付着が少なくなる。よって、図２０に示すように、アルコール濃度が変化しても、内燃機関冷機時のＰＭ排出量、オイル希釈率（オイル中に溶解した燃料の比率）の双方を低減することができる。   According to the fuel injection control of the first embodiment according to the present invention, when the alcohol concentration is low, the fuel adhesion to the crown surface of the piston 12 is small, the adhesion to the cylinder bore wall surface increases, and when the alcohol concentration is high, the piston The fuel adheres to the crown surface of 12 and the adherence to the cylinder bore wall surface decreases. Therefore, as shown in FIG. 20, even if the alcohol concentration changes, both the PM emission amount and the oil dilution rate (ratio of fuel dissolved in oil) when the internal combustion engine is cold can be reduced.

ところで、燃料を吸気行程内で複数回に分割して噴射すると、燃料と空気の混合を促進できることが知られている。この理由について図２１、図２２を用いて説明する。   By the way, it is known that the fuel and air can be mixed when the fuel is divided and injected several times in the intake stroke. The reason for this will be described with reference to FIGS.

図２１は、吸気行程中に２回に分割して噴射した場合と、１回のみの噴射をした場合の、混合気均質性の履歴の一例を示す図である。ここで、混合気均質性とは、燃料と空気が筒内でどれだけ均一に混ざっているかを示す指標であり、値が大きいほど燃料と空気の混合が良いことを示す。混合気均質性は、例えば筒内の当量比空間分布の標準偏差の逆数で定義される。   FIG. 21 is a diagram showing an example of the air-fuel mixture homogeneity history when the fuel is divided into two injections during the intake stroke and when only one injection is performed. Here, the air-fuel mixture homogeneity is an index indicating how uniformly the fuel and air are mixed in the cylinder, and the larger the value, the better the mixing of fuel and air. The air-fuel mixture homogeneity is defined by, for example, the reciprocal of the standard deviation of the equivalence ratio spatial distribution in the cylinder.

図２２は、図２１に対応した最大当量比の履歴を示す図である。ここで最大当量比とは、筒内の局所当量比の最大値である。   FIG. 22 is a diagram showing a history of maximum equivalent ratios corresponding to FIG. Here, the maximum equivalent ratio is the maximum value of the local equivalent ratio in the cylinder.

１回噴射の場合には、吸気行程内の短期間に燃料が集中して供給されるため、噴射直後に当量比の大きな混合気が形成され、均質性は大幅に低下する。   In the case of a single injection, since fuel is concentrated and supplied in a short period of time in the intake stroke, an air-fuel mixture with a large equivalence ratio is formed immediately after injection, and the homogeneity is greatly reduced.

これに対して２回噴射の場合には、１回あたりの噴射量が少ないため、噴射直後の当量比ピーク値は１回噴射に比べて低い。従って、噴射後の均質性の低下が１回噴射に比べて少なくなる。また、１回目と２回目の噴射の間の期間でも、空気と燃料との混合が進むため、圧縮行程後期の点火時期付近では２回噴射の均質性は１回噴射に比べ良くなる。   On the other hand, in the case of two injections, since the injection amount per injection is small, the equivalent ratio peak value immediately after the injection is lower than that in the single injection. Accordingly, the decrease in homogeneity after injection is reduced compared to single injection. Also, since the mixing of air and fuel proceeds during the period between the first and second injections, the homogeneity of the two injections is better than that of the one injection near the ignition timing in the latter half of the compression stroke.

このように、分割噴射は、筒内の局所当量比が過度に高くならないように、時間方向に分散して燃料を投入することで、筒内混合気の均質性を向上できるものである。筒内混合気の均質性が良いと不完全燃焼による損失が減るため、エンジンの燃費、出力、排出ガスが改善される。   As described above, the split injection can improve the homogeneity of the in-cylinder air-fuel mixture by dispersing the fuel in the time direction so that the local equivalent ratio in the cylinder does not become excessively high. If the in-cylinder air-fuel mixture has good homogeneity, the loss due to incomplete combustion is reduced, improving the fuel efficiency, output, and exhaust gas of the engine.

本発明による噴射制御は、ＰＭとオイル希釈の低減のみでなく、混合気の均質性も改善できるものである。以下では、本発明による均質性向上の理由について図２３〜図２６を用いて説明する。   The injection control according to the present invention can not only reduce PM and oil dilution but also improve the homogeneity of the air-fuel mixture. Below, the reason of the homogeneity improvement by this invention is demonstrated using FIGS. 23-26.

図２３は冷機モードにおいて低アルコール濃度燃料を吸気行程内で分割噴射した場合の混合気均質性の履歴を示す図である。混合気均質性の履歴は、初段噴射の割合が低い噴射パターン（Ａ）と、初段噴射の割合が高い噴射パターン（Ｂ）との２つの場合について示している。また、図２４は図２３に示した混合気均質性対応した最大当量比の履歴を示す図である。   FIG. 23 is a diagram showing a history of air-fuel mixture homogeneity when a low alcohol concentration fuel is dividedly injected in the intake stroke in the cold mode. The history of air-fuel mixture homogeneity shows two cases of an injection pattern (A) in which the ratio of the first stage injection is low and an injection pattern (B) in which the ratio of the first stage injection is high. FIG. 24 is a diagram showing a history of the maximum equivalent ratio corresponding to the mixture homogeneity shown in FIG.

アルコール濃度が低い（ガソリン濃度が高い）場合には、低温での気化性が比較的良いため、初段噴射の割合が高い噴射パターン（Ｂ）では、初段噴射後の最大当量比が高くなる。筒内に燃料リッチな混合気が集中して生成される結果、初段噴射後の混合気均質性の低下が大きくなる。   When the alcohol concentration is low (gasoline concentration is high), the vaporization property at a low temperature is relatively good. Therefore, in the injection pattern (B) in which the ratio of the first stage injection is high, the maximum equivalent ratio after the first stage injection becomes high. As a result of the fuel-rich air-fuel mixture being concentrated in the cylinder, the homogeneity of the air-fuel mixture after the first stage injection is greatly reduced.

これに対し、初段噴射の割合が低い噴射パターン（Ａ）では初段噴射後の燃料リッチが緩和され、初段噴射後の混合気均質性の低下が抑制される。この結果、圧縮行程後期の点火時期近傍では、初段噴射の割合が低い噴射パターン（Ａ）の方が混合気均質性を向上できる。   On the other hand, in the injection pattern (A) in which the ratio of the first stage injection is low, the fuel rich after the first stage injection is alleviated, and the deterioration of the air-fuel mixture homogeneity after the first stage injection is suppressed. As a result, in the vicinity of the ignition timing in the latter half of the compression stroke, the mixture homogeneity can be improved in the injection pattern (A) in which the ratio of the first stage injection is low.

図２５は冷機モードにおいて高アルコール濃度燃料を吸気行程内で分割噴射した場合の混合気均質性の履歴を示す図である。混合気均質性の履歴は、初段噴射の割合が低い噴射パターン（Ａ）と、初段噴射の割合が高い噴射パターン（Ｂ）との２つのケースについて示している。また、図２６は図２５に示した混合気均質性に対応した最大当量比の履歴を示す図である。   FIG. 25 is a diagram showing a history of air-fuel mixture homogeneity when high alcohol concentration fuel is dividedly injected in the intake stroke in the cold mode. The air-fuel mixture homogeneity history shows two cases of an injection pattern (A) in which the ratio of the first stage injection is low and an injection pattern (B) in which the ratio of the first stage injection is high. FIG. 26 is a diagram showing a history of maximum equivalent ratios corresponding to the air-fuel mixture homogeneity shown in FIG.

アルコール濃度が高い場合には、低温での気化性がガソリンに比較して低いため、初段噴射の割合が低い噴射パターン（Ａ）では、初段噴射後の最大当量比が低く、終段噴射後の最大当量比が高くなる。これは、初段噴射で投入された燃料の気化が遅く、終段噴射が開始された後も多くの初段燃料が気化するためである。終段噴射後に燃料リッチな混合気が集中して生成される結果、噴射パターン（Ａ）では、終段噴射後の混合気均質性の低下が大きくなる。   When the alcohol concentration is high, the vaporization at low temperature is lower than that of gasoline. Therefore, in the injection pattern (A) where the ratio of the first stage injection is low, the maximum equivalent ratio after the first stage injection is low, The maximum equivalent ratio is increased. This is because the fuel injected in the first stage injection is slow to vaporize, and a lot of the first stage fuel is vaporized even after the final stage injection is started. As a result of the fuel-rich air-fuel mixture being concentrated and generated after the final stage injection, in the injection pattern (A), the homogeneity of the air-fuel mixture after the final stage injection is greatly reduced.

これに対して、初段噴射の割合が高い噴射パターン（Ｂ）では終段噴射後の燃料リッチが緩和され、終段噴射後の混合気均質性の低下が抑制される。この結果、圧縮行程後期の点火時期近傍では、初段噴射の割合が高い噴射パターン（Ｂ）の方が混合気均質性を向上できる。   On the other hand, in the injection pattern (B) in which the ratio of the first stage injection is high, the fuel rich after the final stage injection is alleviated, and the deterioration of the air-fuel mixture homogeneity after the final stage injection is suppressed. As a result, in the vicinity of the ignition timing in the latter half of the compression stroke, the air-fuel mixture homogeneity can be improved with the injection pattern (B) having a higher first-stage injection ratio.

すなわち、本発明によれば、エンジン冷機時において、吸気行程内で初段噴射と終段噴射に分割して噴射し、アルコール濃度が高くなると初段噴射の噴射割合を増やすことで、アルコール濃度が変化してもＰＭ排出とオイル希釈の双方を低減できるとともに、燃料と空気を良好に混合し、燃費、出力、排出ガスの改善が可能となる。   That is, according to the present invention, when the engine is cold, the injection is divided into the first-stage injection and the final-stage injection in the intake stroke, and when the alcohol concentration increases, the alcohol concentration changes by increasing the injection ratio of the first-stage injection. However, both PM emission and oil dilution can be reduced, and fuel and air can be mixed well to improve fuel consumption, output, and exhaust gas.

なお、本発明の実施例１では、吸気行程に、２回に分割して燃料を噴射する例を示したが、燃料分割噴射回数は２回に限定されるものではない。吸気行程で３回以上に分割して燃料を噴射する場合や、吸気行程に加えて他の行程にも燃料が噴射される場合においても、吸気行程の最初の噴射量と、吸気行程の最後の噴射量とがそれぞれピストン１２の冠面への付着量とシリンダボア付着量とを決定付ける。従って、例えば、図２７に示すように、吸気行程で噴射を３回に分割し、圧縮行程にも噴射する場合においては、吸気行程の最初の噴射を初段噴射（噴射期間Ｔ１）、吸気行程の最後の噴射を終段噴射（噴射期間Ｔ２）として、アルコール濃度が高くなると初段噴射割合Ｔ１／（Ｔ１＋Ｔ２）を増やすことで、図１４に示した例と同様の効果が得られる。   In the first embodiment of the present invention, an example is shown in which fuel is injected in two divided portions in the intake stroke, but the number of fuel split injections is not limited to two. Even when fuel is injected in three or more times during the intake stroke, or when fuel is injected into other strokes in addition to the intake stroke, the first injection amount of the intake stroke and the last of the intake stroke The injection amount determines the adhesion amount on the crown surface of the piston 12 and the cylinder bore adhesion amount, respectively. Therefore, for example, as shown in FIG. 27, when the injection is divided into three in the intake stroke and is also injected in the compression stroke, the first injection in the intake stroke is the first stage injection (injection period T1), and the intake stroke The last injection is the final injection (injection period T2), and when the alcohol concentration is increased, the initial injection ratio T1 / (T1 + T2) is increased to obtain the same effect as the example shown in FIG.

また、初段噴射や終段噴射の噴射時期について限定するものではなく、例えば、図２８に示すように、初段噴射の噴射開始時期や終段噴射の噴射終了時期を変化させる例においても、アルコール濃度が高くなると初段噴射割合Ｔ１／（Ｔ１＋Ｔ２）を増やすことで、前記例と同様の効果が得られる。   Further, the injection timing of the first-stage injection and the final-stage injection is not limited. For example, as shown in FIG. 28, the alcohol concentration is also changed in the example of changing the injection start timing of the first-stage injection and the injection end timing of the final-stage injection. When becomes higher, the same effect as in the above example can be obtained by increasing the first stage injection ratio T1 / (T1 + T2).

また、アルコール濃度に対する初段噴射比率の変化方法は一定である必要は無く、内燃機関の運転条件によって変えても良い。例えば、図２９に示すように内燃機関の回転速度が高い時には内燃機関の回転速度が低い時に比べて、同一アルコール濃度における初段噴射の比率が高くなるようにすると良い。回転速度が速い場合にはピストンが高速で下降するため、回転速度が遅い場合に比べて初段噴射がピストンに付着し難くなる。一方、終段噴射は、ピストンの下降が速くなるためシリンダボア壁に付着しやすくなる。   Further, the method of changing the first-stage injection ratio with respect to the alcohol concentration is not necessarily constant, and may be changed depending on the operating conditions of the internal combustion engine. For example, as shown in FIG. 29, when the rotational speed of the internal combustion engine is high, the ratio of the first-stage injection at the same alcohol concentration may be higher than when the rotational speed of the internal combustion engine is low. When the rotational speed is high, the piston descends at a high speed, and therefore, the first-stage injection is less likely to adhere to the piston than when the rotational speed is slow. On the other hand, the final stage injection tends to adhere to the cylinder bore wall because the piston descends faster.

このため、回転速度が速い場合には、回転速度が遅い場合に比べて初段噴射の割合を増やした方が良い。   For this reason, when the rotational speed is fast, it is better to increase the ratio of the first stage injection than when the rotational speed is slow.

また、例えば、図３０に示すように、燃料の噴射圧が低い時には噴射圧が高い時に比べて、同一アルコール濃度における初段噴射の比率が高くなるようにすると良い。燃料噴射圧が低い場合には噴霧の貫徹力（ペネトレーション）が小さくなるので、噴射圧が高い場合に比べて初段噴射がピストン１２の冠面に付着し難くなる。   For example, as shown in FIG. 30, the ratio of the first stage injection at the same alcohol concentration may be higher when the fuel injection pressure is low than when the fuel injection pressure is high. When the fuel injection pressure is low, the penetration force (penetration) of the spray is small, so that the first-stage injection is less likely to adhere to the crown surface of the piston 12 than when the injection pressure is high.

一方、燃料噴射圧が低い場合には、噴霧の粒径が大きくなるので、終段噴射によってシリンダボア壁に付着した燃料の気化性が低くなる。このため、噴射圧が低い場合には、噴射圧が高い場合に比べて初段噴射の割合を増やした方が良い。   On the other hand, when the fuel injection pressure is low, the particle size of the spray becomes large, and the vaporization property of the fuel adhering to the cylinder bore wall by the final stage injection becomes low. For this reason, when the injection pressure is low, it is better to increase the ratio of the first stage injection than when the injection pressure is high.

また、図３１に示すように、アルコール濃度に対して初段噴射の割合に制限を設けても良い。例えばＴ１、Ｔ２の最小値は、使用される燃料噴射弁に許容される最小パルス幅Ｔｍｉｎに制限される。ここでＴｍｉｎは、図３２に示すように、噴射パルス幅と噴射量の関係が線形となる最小噴射パルス幅である。   Moreover, as shown in FIG. 31, you may provide a restriction | limiting in the ratio of the first stage injection with respect to alcohol concentration. For example, the minimum values of T1 and T2 are limited to the minimum pulse width Tmin allowed for the fuel injector used. Here, Tmin is a minimum injection pulse width in which the relationship between the injection pulse width and the injection amount is linear, as shown in FIG.

また、吸気行程内に分割して噴射することで、初段噴射の開始から終段噴射の終了までの期間は１回噴射に比べて長くなる。この噴射期間が長くなりすぎると、燃料の気化や混合時間が減るため、空気と燃料の混合が低下する虞がある。これを防止するために、内燃機関の要求噴射量が予め定めた閾値Ｑｃ以下の場合には、分割噴射をして、アルコール濃度が高いほど前期噴射の割合を増やすように制御して、内燃機関の要求噴射量が予め定めた閾値Ｑｃより多い場合には、吸気行程内の噴射を１回噴射に切り替えてもよい。   Further, by dividing and injecting within the intake stroke, the period from the start of the first stage injection to the end of the final stage injection becomes longer than that of the single injection. If the injection period is too long, the fuel vaporization and mixing time is reduced, which may reduce the mixing of air and fuel. In order to prevent this, when the required injection amount of the internal combustion engine is equal to or less than a predetermined threshold value Qc, divided injection is performed, and control is performed such that the higher the alcohol concentration is, the higher the ratio of the previous injection is. When the required injection amount is greater than a predetermined threshold value Qc, the injection in the intake stroke may be switched to a single injection.

さらに、本発明の実施例１においては、アルコール濃度センサ４を用いて燃料タンク３内の燃料アルコール濃度を検出するようにしたが、アルコール濃度センサ４を用いずに、空燃比センサの出力、要求噴射量、機関回転速度などから、アルコール濃度を推定しても良い。   Furthermore, in Embodiment 1 of the present invention, the alcohol concentration sensor 4 is used to detect the fuel alcohol concentration in the fuel tank 3, but without using the alcohol concentration sensor 4, the output and demand of the air-fuel ratio sensor are detected. The alcohol concentration may be estimated from the injection amount, engine speed, and the like.

また、内燃機関の始動直後のアルコール濃度を取得するには、例えば、前回の機関運転時に推定されたアルコール濃度をメモリ等に記憶しておき、この値を始動直後に読み出し、アルコール濃度として用いてもよい。   In order to obtain the alcohol concentration immediately after starting the internal combustion engine, for example, the alcohol concentration estimated during the previous engine operation is stored in a memory or the like, and this value is read out immediately after starting and used as the alcohol concentration. Also good.

以上のように、本発明の実施例１によれば、アルコールとガソリンとの混合燃料を噴射する燃料噴射制御装置において、混合燃料のアルコール濃度と内燃機関のピストンの上下運動とに応じて適切に燃料噴射弁からの燃料噴射期間を調節することにより、燃料と空気との混合を良好に維持しつつ、内燃機関冷機時のＰＭの生成とオイル希釈とを低減することが可能となる。   As described above, according to the first embodiment of the present invention, in the fuel injection control device that injects the mixed fuel of alcohol and gasoline, the fuel injection control device appropriately according to the alcohol concentration of the mixed fuel and the vertical movement of the piston of the internal combustion engine. By adjusting the fuel injection period from the fuel injection valve, it is possible to reduce the generation of PM and the oil dilution when the internal combustion engine is cold while maintaining good mixing of fuel and air.

つまり、内燃機関の吸気行程における燃料噴射期間を複数の期間に分割し、アルコールとガソリンとの混合燃料のアルコール濃度に応じて初段噴射期間及び終段噴射期間を変更し、アルコール濃度が低の場合は、初段噴射期間を短く、終段噴射期間を長くし、アルコール濃度が高くなるにつれて、初段噴射期間を長くし、終段噴射期間を短くして、ピストンの冠面と、シリンダボア壁面への燃料噴射量を調整する。これは、分割噴射の初段の噴射量をＱ１、分割噴射の終段の噴射量をＱ２としたときに、Ｑ１／（Ｑ１＋Ｑ２）を混合燃料のアルコール濃度が高いほど大きくすることである。   That is, when the fuel injection period in the intake stroke of the internal combustion engine is divided into a plurality of periods, the first injection period and the final injection period are changed according to the alcohol concentration of the mixed fuel of alcohol and gasoline, and the alcohol concentration is low Shortens the initial stage injection period, lengthens the final stage injection period, and as the alcohol concentration increases, increases the initial stage injection period and shortens the final stage injection period to reduce the fuel to the piston crown and cylinder bore wall surfaces. Adjust the injection amount. This is to increase Q1 / (Q1 + Q2) as the alcohol concentration of the mixed fuel increases, where Q1 is the initial injection amount of the divided injection and Q2 is the final injection amount of the divided injection.

これによって、ガソリン濃度が高い場合のピストン冠面への燃料付着と、アルコール濃度が高い場合の、シリンダボア壁面への燃料付着を抑制でき、内燃機関冷機時のＰＭの生成とオイル希釈とを低減することが可能となる。また、燃料噴射期間を複数の期間に分割することによって、燃料と空気との混合を良好に維持することが可能となる。   As a result, fuel adhesion to the piston crown when the gasoline concentration is high and fuel adhesion to the cylinder bore wall surface when the alcohol concentration is high can be suppressed, reducing PM generation and oil dilution when the internal combustion engine is cold. It becomes possible. Further, by dividing the fuel injection period into a plurality of periods, it is possible to maintain good mixing of fuel and air.

（実施例２）
次に、本発明の実施例２について説明する。上述した実施例１は、燃料噴射期間を変更して噴射量を調整する例であるが、混合燃料のアルコール濃度に応じて、初段噴射と終段噴射の噴射量を調整するには、噴射期間を変える代わりに、燃料噴射弁の弁リフト高さを変えてもよい。本発明の実施例２は、燃料噴射弁の弁リフト高さによって、冷機モードにおける燃料噴射料を制御する例である。 (Example 2)
Next, a second embodiment of the present invention will be described. The first embodiment described above is an example in which the injection amount is adjusted by changing the fuel injection period, but in order to adjust the injection amount of the first stage injection and the final stage injection according to the alcohol concentration of the mixed fuel, the injection period Instead of changing the above, the valve lift height of the fuel injection valve may be changed. Embodiment 2 of the present invention is an example in which the fuel injection fee in the cold machine mode is controlled by the valve lift height of the fuel injection valve.

なお、本発明の実施例２が適用される内燃機関における制御系は、図１に示した実施例１の制御系と同様であるので、図示及び説明は省略する。   The control system in the internal combustion engine to which the second embodiment of the present invention is applied is the same as the control system of the first embodiment shown in FIG.

図３４は、本発明の実施例２における燃料噴射弁１０６の内部構造を示す概略断面図であり、図３５は、図３４に示した燃料噴射弁１０６の絞り部３０の拡大概略断面図である。   FIG. 34 is a schematic cross-sectional view showing the internal structure of the fuel injection valve 106 according to the second embodiment of the present invention, and FIG. 35 is an enlarged schematic cross-sectional view of the throttle portion 30 of the fuel injection valve 106 shown in FIG. .

図３４、図３５において、ノズル２５は円筒状でその内部に弁体２６が挿入されており、弁体２６はノズル２５に対して軸方向に動く構造になっている。そして、弁体２６とノズル２５には、弁体２６の軸方向の動きを案内するための弁体側ガイド部２７とノズル側ガイド部２８が設けられている。弁体２６はノズル２５の内径よりも細くなっており、弁体２６とノズル２７との間の隙間が燃料流路２８となっている。   34 and 35, the nozzle 25 is cylindrical and has a valve body 26 inserted therein, and the valve body 26 is structured to move in the axial direction with respect to the nozzle 25. The valve body 26 and the nozzle 25 are provided with a valve body side guide portion 27 and a nozzle side guide portion 28 for guiding the axial movement of the valve body 26. The valve body 26 is thinner than the inner diameter of the nozzle 25, and a gap between the valve body 26 and the nozzle 27 serves as a fuel flow path 28.

通常の状態では、弁体２６は閉弁用ばね２９により上方向に引っ張られているため、弁体２６とノズル２５は絞り部３０において接触し燃料は噴射されない。弁体２６の上側には、弁体２６の軸方向のリフト量を制御するためのピエゾユニット３２が設けられている。ピエゾユニット３２からはリード線３３が噴射弁外部に引き出されている。   In a normal state, since the valve body 26 is pulled upward by the valve closing spring 29, the valve body 26 and the nozzle 25 come into contact with each other at the throttle portion 30, and fuel is not injected. A piezo unit 32 for controlling the lift amount of the valve body 26 in the axial direction is provided on the upper side of the valve body 26. A lead wire 33 is drawn from the piezo unit 32 to the outside of the injection valve.

リード線３３に電圧が印加されるとピエゾユニット３２が軸方向に伸び、弁体２６が押し下げられて絞り部３０に間隙が生じ、この隙間から燃料流路２８内の高圧燃料が燃料液膜３６として外部に噴出する。弁体２６及びノズル２５のテーパ面３２にそって燃料が流れるため、噴射される燃料液膜は中空円錐形状となる。液膜３６の厚さは噴口から離れるに従い薄くなり、その先端が***して微細な液滴３７が発生する。   When a voltage is applied to the lead wire 33, the piezo unit 32 extends in the axial direction, the valve body 26 is pushed down to create a gap in the throttle portion 30, and the high-pressure fuel in the fuel flow path 28 is transferred from the gap to the fuel liquid film 36. Erupt outside. Since fuel flows along the tapered surface 32 of the valve body 26 and the nozzle 25, the injected fuel liquid film has a hollow conical shape. The thickness of the liquid film 36 decreases as the distance from the nozzle hole increases, and the tip of the liquid film 36 is split to generate fine droplets 37.

弁体２６のリフト量はピエゾユニット３２に印加する電圧に比例し、印加電圧を変えることで図３６に示すように弁体２６のリフト高さを任意に変更することができる。また、図３７に示すように、噴射期間が一定であれば、噴射量は弁リフト高さにほぼ比例する。   The lift amount of the valve body 26 is proportional to the voltage applied to the piezo unit 32. By changing the applied voltage, the lift height of the valve body 26 can be arbitrarily changed as shown in FIG. As shown in FIG. 37, if the injection period is constant, the injection amount is substantially proportional to the valve lift height.

図３８は、本発明の実施例２による、冷機モードにおける燃料の噴射タイミングのチャートを示す図である。図３８において、冷機モードでは、燃料は吸気行程内に２回に分割して噴射する。ここでは、２回に分割した前側の噴射を初段噴射、その時の燃料噴射弁のリフト高さをｈ１と定義する。また２回に分割した後側の噴射を終段噴射、その時の燃料噴射弁のリフト高さをｈ２と定義する。   FIG. 38 is a diagram illustrating a chart of fuel injection timing in the cold machine mode according to the second embodiment of the present invention. In FIG. 38, in the cold mode, the fuel is divided and injected twice in the intake stroke. Here, the front injection divided into two times is defined as the first stage injection, and the lift height of the fuel injection valve at that time is defined as h1. Further, the rear injection divided into two is defined as final injection, and the lift height of the fuel injection valve at that time is defined as h2.

初段噴射は吸気行程の前半に実施され、その噴射開始時期は例えば吸気上死点後３０ｄｅｇＣＡである。一方、終段噴射は吸気行程の後半に実施され、その噴射終了時期は例えば１２０ｄｅｇＣＡである。   The first stage injection is performed in the first half of the intake stroke, and the injection start timing is, for example, 30 deg CA after the intake top dead center. On the other hand, the final stage injection is performed in the latter half of the intake stroke, and the injection end timing is, for example, 120 degCA.

図３８に示すように、本発明の実施例２では、リフト高さｈ１とｈ２とを燃料のアルコール濃度によって変化させ、アルコール濃度が高いほど、ｈ１を高く、ｈ２を低く設定する。また、初段噴射と終段噴射の噴射期間は、アルコール濃度が変化しても一定に保つ。これによってアルコール濃度が高いほど、初段噴射の噴射量比率が高く、終段噴射の噴射量比率が低く設定される。   As shown in FIG. 38, in the second embodiment of the present invention, the lift heights h1 and h2 are changed depending on the alcohol concentration of the fuel, and as the alcohol concentration is higher, h1 is set higher and h2 is set lower. Further, the injection period of the first stage injection and the last stage injection is kept constant even if the alcohol concentration changes. As a result, the higher the alcohol concentration, the higher the injection amount ratio of the first-stage injection and the lower the injection amount ratio of the final-stage injection.

このとき、図３９に示すように、アルコール濃度の増加に対して、初段噴射の比率ｈ１／（ｈ１＋ｈ２）を連続的に増やしても良い。また、図４０に示すように、アルコール濃度の増加に対して、初段噴射の比率ｈ１／（ｈ１＋ｈ２）を段階的に増やしても良い。   At this time, as shown in FIG. 39, the ratio h1 / (h1 + h2) of the first stage injection may be continuously increased with respect to the increase in the alcohol concentration. Further, as shown in FIG. 40, the ratio h1 / (h1 + h2) of the first stage injection may be increased stepwise as the alcohol concentration increases.

本発明の実施例２におけるエンジン始動後の運転モード切替フローは図１２に示したフローと同様であり、ＥＣＵ１１２内のエンジン始動後の運転モード切替についての機能ブロックは、図１３に示した機能ブロックと同様となる。ただし、燃料噴射制御部１１２ｄは、アルコール濃度と、燃料噴射時期（初段噴射又は後段噴射）とにより、メモリ１１２ｃに格納された噴射弁リフト高さを検索し、検索したデータに従って燃料噴射弁１０６の噴射弁リフト高さを制御する。   The operation mode switching flow after engine start in the second embodiment of the present invention is the same as the flow shown in FIG. 12, and the functional block for operation mode switching after engine start in the ECU 112 is the function block shown in FIG. It will be the same. However, the fuel injection control unit 112d searches for the injector lift height stored in the memory 112c based on the alcohol concentration and the fuel injection timing (first-stage injection or subsequent-stage injection), and determines the fuel injection valve 106 according to the searched data. Controls the lift height of the injection valve.

本発明の実施例２においても、実施例１と同様な効果を得ることができる。   In the second embodiment of the present invention, the same effect as in the first embodiment can be obtained.

また、本発明の実施例２では、燃料噴射量を燃料噴射弁１０６のリフト高さで変更するため、アルコール濃度変化に対して噴射期間を一定にすることができる。例えば、アルコール濃度が高く初段噴射の割合を増やしたいときに、初段噴射の噴射期間を長くすると、初段噴射の噴射終了時期が遅くなって、初段噴射がシリンダボアに付着する量が増大する虞がある。しかし、噴射期間を一定にして噴射量を噴射弁のリフト高さで変更すれば、この問題を回避できる。   Further, in the second embodiment of the present invention, the fuel injection amount is changed by the lift height of the fuel injection valve 106, so that the injection period can be made constant with respect to the alcohol concentration change. For example, when the alcohol concentration is high and it is desired to increase the ratio of the first-stage injection, if the injection period of the first-stage injection is lengthened, the injection end timing of the first-stage injection is delayed, and the amount of the first-stage injection attached to the cylinder bore may increase. . However, this problem can be avoided if the injection amount is changed by the lift height of the injection valve while making the injection period constant.

（実施例３）
次に、本発明の実施例３について説明する。上述した実施例１、２は、燃料噴射期間又は燃料噴射弁のリフト量を変更して噴射量を調整する例であるが、混合燃料のアルコール濃度に応じて、初段噴射と終段噴射の噴射量を調整するには噴射期間、噴射弁リフト量を変える代わりに、燃料噴射圧を変えることで、噴射量の比率を変えても良い。本発明の実施例３は、燃料噴射弁の燃料噴射圧を調整することによって、冷機モードにおける燃料噴射を制御する例である。 (Example 3)
Next, Embodiment 3 of the present invention will be described. In the first and second embodiments described above, the injection amount is adjusted by changing the fuel injection period or the lift amount of the fuel injection valve. However, the first-stage injection and the final-stage injection are performed according to the alcohol concentration of the mixed fuel. In order to adjust the amount, instead of changing the injection period and the injection valve lift amount, the ratio of the injection amount may be changed by changing the fuel injection pressure. Embodiment 3 of the present invention is an example of controlling fuel injection in the cold machine mode by adjusting the fuel injection pressure of the fuel injection valve.

図４１は、本発明の実施例３における筒内噴射式エンジンの概略構成図である。図４１において、筒内噴射エンジン１にはシリンダヘッドの側方に第一燃料弁１０６ａを備え、シリンダヘッドの上部中央部に第二燃料噴射弁１０６ｂを備えている。第一燃料噴射弁１０６ａには第一高圧燃料ポンプ２ａから高圧燃料配管７ｂａを介して燃料が供給され、第二燃料噴射弁１０６ｂには第二の高圧燃料ポンプ２ｂから高圧燃料配管７ｂｂを介して燃料が供給される。高圧燃料ポンプ２ａと高圧燃料ポンプ２ｂはＥＣＵ１１２から供給される噴射圧指令値信号Ｓ２ａ、Ｓ２ｂによってそれぞれ独立に噴射圧が設定される。   FIG. 41 is a schematic configuration diagram of a direct injection engine according to the third embodiment of the present invention. In FIG. 41, the in-cylinder injection engine 1 includes a first fuel valve 106a on the side of the cylinder head, and a second fuel injection valve 106b in the upper center portion of the cylinder head. Fuel is supplied to the first fuel injection valve 106a from the first high-pressure fuel pump 2a through the high-pressure fuel pipe 7ba, and to the second fuel injection valve 106b from the second high-pressure fuel pump 2b to the high-pressure fuel pipe 7bb. Fuel is supplied. The high pressure fuel pump 2a and the high pressure fuel pump 2b are independently set with injection pressures by injection pressure command value signals S2a and S2b supplied from the ECU 112.

一般に燃料噴射弁から噴射される噴霧の粒径は、噴射圧が高くなると小さく、噴射圧が低くなると大きくなる。噴射圧に対する粒径の感度は噴射弁の微粒化方式によって異なる。   In general, the particle size of the spray injected from the fuel injection valve decreases as the injection pressure increases, and increases as the injection pressure decreases. The sensitivity of the particle size to the injection pressure varies depending on the atomization method of the injection valve.

図４２は、燃料噴射弁１０６ａと１０６ｂの噴射圧に対する噴霧粒径の関係を示すグラフである。第二燃料噴射弁１０６ｂは噴射圧に対する粒径感度が小さいものが良く、例えば旋回流式噴射弁（スワール弁）や外開き式噴射弁などが適している。   FIG. 42 is a graph showing the relationship of the spray particle diameter to the injection pressure of the fuel injection valves 106a and 106b. The second fuel injection valve 106b preferably has a small particle size sensitivity with respect to the injection pressure. For example, a swirling flow type injection valve (swirl valve) or an externally open type injection valve is suitable.

第一燃料噴射弁１０６ａは、吸気弁などへの燃料付着を防ぐために、比較的噴霧角が狭いものが適しており、単孔式噴射弁や多孔式噴射弁（マルチホールインジェクタ）などが適している。一般に、単孔式噴射弁や多孔式噴射弁は、噴射圧に対する粒径感度は高い。   The first fuel injection valve 106a is suitable for a fuel having a relatively narrow spray angle in order to prevent fuel from adhering to the intake valve or the like, and a single-hole injection valve, a multi-hole injection valve (multi-hole injector) or the like is suitable. Yes. In general, a single-hole injection valve or a multi-hole injection valve has high particle size sensitivity to injection pressure.

第一燃料噴射弁１０６ａ及び第二燃料噴射弁１０６ｂは、ＥＣＵ１１２から供給される指令信号Ｓ３ａ、Ｓ３ｂによって動作が制御される。   The operations of the first fuel injection valve 106a and the second fuel injection valve 106b are controlled by command signals S3a and S3b supplied from the ECU 112.

図４３は、本発明の実施例３による、冷機モードにおける燃料の噴射タイミングチャートを示す図である。冷機モードでは、燃料は吸気行程内に２回に分割して噴射する。   FIG. 43 is a diagram showing a fuel injection timing chart in the cold machine mode according to the third embodiment of the present invention. In the cold machine mode, the fuel is divided and injected twice in the intake stroke.

初段噴射は燃料噴射弁１０６ａによって吸気行程の前半に実施され、その噴射開始時期は例えば吸気上死点後３０ｄｅｇＣＡである。一方、終段噴射は燃料噴射弁１０６ｂによって吸気行程の後半に実施され、その噴射終了時期は例えば１２０ｄｅｇＣＡである。   The first stage injection is performed in the first half of the intake stroke by the fuel injection valve 106a, and the injection start timing is, for example, 30 deg CA after the intake top dead center. On the other hand, the final stage injection is performed in the latter half of the intake stroke by the fuel injection valve 106b, and the injection end timing is, for example, 120 degCA.

図４４は、本発明の実施例３による、燃料のアルコール濃度に対する噴射圧の設定例を示す図である。初段噴射を実施する第一燃料噴射弁１０６ａの噴射圧はアルコール濃度の増加に伴って高くなるように設定する。一方、終段噴射を実施する第二燃料噴射弁１０６ｂの噴射圧は、アルコール濃度の増加に伴って低くなるように設定する。   FIG. 44 is a diagram illustrating a setting example of the injection pressure with respect to the alcohol concentration of the fuel according to the third embodiment of the present invention. The injection pressure of the first fuel injection valve 106a that performs the first-stage injection is set to increase as the alcohol concentration increases. On the other hand, the injection pressure of the second fuel injection valve 106b that performs the final stage injection is set so as to decrease as the alcohol concentration increases.

本発明の実施例３におけるエンジン始動後の運転モード切替フローは図１２に示したフローと同様であり、ＥＣＵ１１２内のエンジン始動後の運転モード切替についての機能ブロックは、図１３に示した機能ブロックと同様となる。ただし、燃料噴射制御部１１２ｄは、アルコール濃度と、燃料噴射時期（初段噴射又は後段噴射）、燃料噴射弁の区別により、メモリ１１２ｃに格納された燃料噴射圧力を検索し、検索したデータに従って燃料噴射弁１０６ａ、１０６ｂの燃料噴射圧力を制御する。また、図１３のインジェクタ１０６は、燃料ポンプ２ａ、２ｂに置き換えられる。   The operation mode switching flow after engine start in the third embodiment of the present invention is the same as the flow shown in FIG. 12, and the functional block for operation mode switching after engine start in the ECU 112 is the function block shown in FIG. It will be the same. However, the fuel injection control unit 112d searches for the fuel injection pressure stored in the memory 112c based on the alcohol concentration, the fuel injection timing (first-stage injection or subsequent-stage injection), and the fuel injection valve, and performs fuel injection according to the searched data. The fuel injection pressure of the valves 106a and 106b is controlled. Further, the injector 106 in FIG. 13 is replaced with the fuel pumps 2a and 2b.

このように、それぞれの燃料噴射弁１０６ａ、１０６ｂの噴射圧力を設定することで、アルコール濃度が高いほど、初段噴射の噴射量比率を高く、終段噴射の噴射量比率を低く設定することができる。   Thus, by setting the injection pressures of the respective fuel injection valves 106a and 106b, the higher the alcohol concentration, the higher the injection amount ratio of the first-stage injection and the lower the injection amount ratio of the final-stage injection. .

上述したように、噴射圧で燃料噴射量を制御すると、アルコール濃度変化に対して燃料噴射期間を一定にできるので、前述の噴射弁のリフト量による噴射量制御と同様の利点がある。   As described above, when the fuel injection amount is controlled by the injection pressure, the fuel injection period can be made constant with respect to the change in the alcohol concentration. Therefore, there is an advantage similar to the above-described injection amount control by the lift amount of the injection valve.

また、燃料噴射圧によって噴霧の貫徹力（ペネトレーション）が変化するので、この効果によって燃料の壁面付着をさらに減らすことができる。例えば、本発明の実施例３による燃料噴射制御では、アルコール濃度が低い場合には、初段噴射の噴射圧を低く設定する。噴射圧が低くなると噴霧の貫徹力が下がるので、初段噴射の噴霧のピストン１２の冠面への付着を減らすことができる。これによって、更にＰＭを低減できる。   Further, since the penetration force (penetration) of the spray changes depending on the fuel injection pressure, this effect can further reduce the fuel wall surface adhesion. For example, in the fuel injection control according to the third embodiment of the present invention, when the alcohol concentration is low, the injection pressure of the first stage injection is set low. Since the penetration force of the spray is lowered when the injection pressure is lowered, the adhesion of the spray of the first stage spray to the crown surface of the piston 12 can be reduced. Thereby, PM can be further reduced.

また、本発明の実施例３による燃料噴射制御では、アルコール濃度が高い場合には、終段噴射の燃料噴射圧を低く設定する。燃料噴射圧を低く設定すると、終段噴射の貫徹力が下がる。また、終段噴射を実施する噴射弁は、噴射圧に対して粒径感度が小さいので、噴射圧が低くても粒径はあまり増大しない。これらによって噴霧のシリンダボア壁への付着が減り、更にオイル希釈を低減することができる。   Further, in the fuel injection control according to the third embodiment of the present invention, when the alcohol concentration is high, the fuel injection pressure of the final stage injection is set low. When the fuel injection pressure is set low, the penetration force of the final stage injection is lowered. Further, since the injection valve that performs the final injection has a small particle size sensitivity with respect to the injection pressure, the particle size does not increase so much even if the injection pressure is low. As a result, adhesion of the spray to the cylinder bore wall is reduced, and oil dilution can be further reduced.

また、本発明の実施例３の筒内噴射エンジンのように、１つの気筒に２つの燃料噴射弁１０６ａ、１０６ｂが設けられている場合には、それぞれの噴射弁からの噴射期間を変えることでも、燃料噴射比率を変えることができる。具体的には、噴射弁１０６ｂの噴射圧と噴射弁１０６ａの噴射圧との比をアルコール濃度に対して一定とし、図４５に示すように、初段噴射を実施する第一燃料噴射弁１０６ａの噴射期間をアルコール濃度の増加に伴って長くなるように設定する。一方、終段噴射を実施する第二燃料噴射弁１０６ｂの噴射期間を、アルコール濃度の増加に伴って低くなるように設定する。   Further, when two fuel injection valves 106a and 106b are provided in one cylinder as in the in-cylinder injection engine of the third embodiment of the present invention, it is also possible to change the injection period from each injection valve. The fuel injection ratio can be changed. Specifically, the ratio of the injection pressure of the injection valve 106b and the injection pressure of the injection valve 106a is made constant with respect to the alcohol concentration, and as shown in FIG. 45, the injection of the first fuel injection valve 106a that performs the first stage injection The period is set to become longer as the alcohol concentration increases. On the other hand, the injection period of the second fuel injection valve 106b for carrying out the final stage injection is set so as to decrease as the alcohol concentration increases.

このように、それぞれの燃料噴射弁１０６ａ、１０６ｂの噴射期間を設定することで、アルコール濃度が高いほど、初段噴射の燃料噴射量比率を高く、終段噴射の燃料噴射量比率を低く設定することができる。   In this way, by setting the injection period of each of the fuel injection valves 106a and 106b, the higher the alcohol concentration, the higher the fuel injection amount ratio of the first stage injection and the lower the fuel injection amount ratio of the final stage injection. Can do.

なお、初段噴射と終段噴射を担当する燃料噴射弁を入れ替え、初段噴射を１０６ｂで実施し、終段噴射を１０６ａで実施してもよい。この場合には、初段噴射を実施する燃料噴射弁１０６ｂの噴射期間はアルコール濃度の増加に伴って長くなるように設定し、終段噴射を実施する燃料噴射弁１０６ａの噴射期間は、アルコール濃度の増加に伴って短くなるように設定する。   The fuel injection valves in charge of the first-stage injection and the final-stage injection may be exchanged, the first-stage injection may be performed at 106b, and the final-stage injection may be performed at 106a. In this case, the injection period of the fuel injection valve 106b that performs the first-stage injection is set to be longer as the alcohol concentration increases, and the injection period of the fuel injection valve 106a that performs the final-stage injection is the alcohol concentration. Set to be shorter as it increases.

また、燃料噴射期間、燃料噴射弁のリフト高さ、燃料噴射圧力を組み合わせて燃料噴射比率を変えても良い。これらを組み合わせることで、燃料噴射比率をより広い範囲で変更できるので、エンジンの運転条件に合わせてより柔軟な燃料噴射制御が可能になる。   Further, the fuel injection ratio may be changed by combining the fuel injection period, the lift height of the fuel injection valve, and the fuel injection pressure. By combining these, the fuel injection ratio can be changed in a wider range, so that more flexible fuel injection control can be performed according to the operating conditions of the engine.

なお、本発明の対象となる筒内直噴式のエンジンは、図４６に示すような直上噴射式エンジン１ｂであってもよい。直上噴射式エンジン１ｂは、燃料噴射弁１０６がピストン１２の冠面に対向する直上部に配置ざれている。   Note that the direct injection type engine 1b shown in FIG. 46 may be the in-cylinder direct injection type engine that is the subject of the present invention. In the direct injection type engine 1 b, the fuel injection valve 106 is arranged at an upper portion facing the crown surface of the piston 12.

直上噴射式エンジン１ｂにおいて、燃料噴射開始タイミングが吸気行程の前期、例えば吸気上死点後３０ｄｅｇＣＡの場合の噴霧挙動の例を図４７に示す。図４７において、吸気行程の前期ではピストン１２は高い位置（上死点に近い位置）にあるため、燃料噴射弁１０６からの燃料噴霧の殆どは、ピストン１２の冠面に衝突する。内燃機関が冷機状態のときは、ピストン１２の冠面の温度が低いため、冠面に衝突した液滴の多くは、ピストン１２の冠面上に液膜を形成する。   FIG. 47 shows an example of the spray behavior in the direct injection type engine 1b when the fuel injection start timing is in the first half of the intake stroke, for example, 30 deg CA after the intake top dead center. In FIG. 47, since the piston 12 is at a high position (position close to top dead center) in the first half of the intake stroke, most of the fuel spray from the fuel injection valve 106 collides with the crown surface of the piston 12. When the internal combustion engine is in a cold state, the temperature of the crown surface of the piston 12 is low, so that most of the droplets that collide with the crown surface form a liquid film on the crown surface of the piston 12.

図４８は、直上噴射式エンジン１ｂにおいて、燃料噴射開始タイミングが吸気行程の後期、例えば吸気上死点後１２０ｄｅｇＣＡの場合の噴霧挙動の例を示す図である。   FIG. 48 is a diagram showing an example of the spray behavior in the case of the direct injection type engine 1b when the fuel injection start timing is late in the intake stroke, for example, 120 deg CA after the intake top dead center.

吸気行程の後期ではピストン１２は低い位置（上死点から離れた位置）にあるため、燃料噴射弁１０６からの燃料噴霧の一部が燃焼室ボア壁面に衝突する。内燃機関が冷機状態のときは、燃焼室ボア壁面の温度が低いため、燃焼室ボア壁面に衝突した液滴の多くは、燃焼室ボア壁面上に液膜を形成する。   In the latter stage of the intake stroke, the piston 12 is in a low position (a position away from the top dead center), so that part of the fuel spray from the fuel injection valve 106 collides with the combustion chamber bore wall surface. When the internal combustion engine is in a cold state, the temperature of the combustion chamber bore wall surface is low, so that many of the droplets that collide with the combustion chamber bore wall surface form a liquid film on the combustion chamber bore wall surface.

このように、直上噴射式エンジン１ｂにおいても、シリンダヘッドの側方から燃料が噴射されるエンジンの場合と同様に、吸気行程の初期に噴射する燃料はピストン１２の冠面に多く付着し、吸気行程の後期に噴射すると燃料はシリンダボア壁面に多く付着する。   Thus, in the direct injection type engine 1b as well, in the case of the engine in which fuel is injected from the side of the cylinder head, a lot of fuel injected in the initial stage of the intake stroke adheres to the crown surface of the piston 12, and the intake air When injected later in the stroke, more fuel adheres to the cylinder bore wall.

従って、冷機モードにおける吸気行程期間内に、期間を分割して燃料を噴射し、アルコール濃度が高いほど、初段噴射量の割合を多くすることで、アルコール濃度が変化した場合にＰＭ排出とオイル希釈の双方を低減することができる。   Therefore, during the intake stroke period in the cold machine mode, fuel is injected in divided periods, and the higher the alcohol concentration, the greater the proportion of the first stage injection amount, so that when the alcohol concentration changes, PM emissions and oil dilution Both of them can be reduced.

なお、本発明は上記した実施例に限定されるものではなく、様々な変形例が含まれる。例えば、上記した実施例は本発明を分かりやすく説明するために詳細に説明したものであり、必ずしも説明した全ての構成を備えるものに限定されるものではない。   In addition, this invention is not limited to an above-described Example, Various modifications are included. For example, the above-described embodiments have been described in detail for easy understanding of the present invention, and are not necessarily limited to those having all the configurations described.

また、ある実施例の構成の一部を他の実施例の構成に置き換えることが可能であり、ある実施例の構成に他の実施例の構成を加えることも可能である。また、各実施例の構成の一部について、他の構成の追加・削除・置換をすることが可能である。   Further, a part of the configuration of one embodiment can be replaced with the configuration of another embodiment, and the configuration of another embodiment can be added to the configuration of one embodiment. Further, it is possible to add, delete, and replace other configurations for a part of the configuration of each embodiment.

また、上記の各構成、機能、処理部、処理手段等は、それらの一部または全部を、例えば集積回路で設計する等によりハードウェアで実現してもよい。また、上記の各構成、機能等は、プロセッサがそれぞれの機能を実現するプログラムを解釈し、実行することによりソフトウェアで実現してもよい。各機能を実現するプログラム、テーブル、ファイル等の情報は、メモリやハードディスク等の記憶装置、またはＩＣカード、ＳＤカード、ＤＶＤ等の記憶媒体に置くことができる。   Each of the above-described configurations, functions, processing units, processing means, and the like may be realized by hardware by designing a part or all of them with, for example, an integrated circuit. Each of the above-described configurations, functions, and the like may be realized by software by interpreting and executing a program that realizes each function by the processor. Information such as programs, tables, and files that realize each function can be stored in a storage device such as a memory or a hard disk, or a storage medium such as an IC card, an SD card, or a DVD.

また、制御線や情報線は説明上必要と考えられるものを示しており、製品上必ずしも全ての制御線や情報線を示しているとは限らない。実際には殆どの構成が相互に接続されていると考えてよい。   Further, the control lines and information lines indicate what is considered necessary for the explanation, and not all the control lines and information lines on the product are necessarily shown. In practice, it can be considered that most of the configurations are connected to each other.

１、１ｂ・・・内燃機関、２、２ａ、２ｂ・・・高圧燃料ポンプ、４・・・アルコール濃度センサ、５・・・フィードポンプ、６・・・混合燃料、７ａ、７ｂ・・・燃料配管、９・・・噴射圧力センサ、１０・・・スロットル弁、１１・・・冷却水温センサ、１２・・・ピストン、１３・・・吸気弁、１４・・・排気弁、１５・・・シリンダヘッド、１６・・・シリンダブロック、２０、２６・・・弁体、２１・・・噴口、２５・・・ノズル、２７・・・弁体側ガイド部、２８・・・ノズル側ガイド部、２９・・・開弁用ばね、３０・・・絞り部、３２・・・ピエゾユニット、１０６・・・燃料噴射弁、１０７・・・点火プラグ、１１２・・・ＥＣＵ、１１２ａ・・・アルコール濃度判断部、１１２ｂ・・・冷機状態判断部、１１２ｃ・・・メモリ、１１２ｄ・・・燃料噴射制御部   DESCRIPTION OF SYMBOLS 1, 1b ... Internal combustion engine, 2, 2a, 2b ... High pressure fuel pump, 4 ... Alcohol concentration sensor, 5 ... Feed pump, 6 ... Mixed fuel, 7a, 7b ... Fuel Piping, 9 ... Injection pressure sensor, 10 ... Throttle valve, 11 ... Cooling water temperature sensor, 12 ... Piston, 13 ... Intake valve, 14 ... Exhaust valve, 15 ... Cylinder Head, 16 ... Cylinder block, 20, 26 ... Valve element, 21 ... Injection hole, 25 ... Nozzle, 27 ... Valve element side guide part, 28 ... Nozzle side guide part, 29 ..Valve opening spring, 30 ... throttle part, 32 ... piezo unit, 106 ... fuel injection valve, 107 ... ignition plug, 112 ... ECU, 112a ... alcohol concentration determination part , 112b... Cold state determination unit, 112c. Mori, 112d ··· fuel injection control unit

Claims (18)

ガソリンとアルコールとの混合燃料のアルコール濃度を検出するアルコール濃度センサと、
内燃機関の温度を検出する温度センサと、
上記混合燃料を筒内に噴射する筒内噴射式の燃料噴射弁と、
上記温度センサが検出した温度に従って内燃機関が冷機状態であると判断した場合には、内燃機関の吸気行程を複数の燃料噴射期間に分割し、分割した燃料噴射期間の内の初期の燃料噴射期間の燃料噴射量を、上記アルコール濃度センサが検出したアルコール濃度が高くなるに従って多くし、上記分割した期間の内の後期の燃料噴射期間の燃料噴射量を、上記アルコール濃度センサが検出したアルコール濃度が高くなるに従って少なくして、上記燃料噴射弁が噴射する混合燃料の噴射量を制御する制御部と、
を備えること特徴とする内燃機関の燃料噴射制御装置。 An alcohol concentration sensor that detects the alcohol concentration of a mixed fuel of gasoline and alcohol;
A temperature sensor for detecting the temperature of the internal combustion engine;
An in- cylinder fuel injection valve that injects the mixed fuel into the cylinder ;
When it is determined that the internal combustion engine is in the cold state according to the temperature detected by the temperature sensor, the intake stroke of the internal combustion engine is divided into a plurality of fuel injection periods, and an initial fuel injection period among the divided fuel injection periods The fuel injection amount is increased as the alcohol concentration detected by the alcohol concentration sensor increases, and the fuel injection amount in the latter fuel injection period of the divided periods is determined by the alcohol concentration detected by the alcohol concentration sensor. A control unit that controls the injection amount of the mixed fuel that is injected by the fuel injection valve, which is decreased as it becomes higher;
A fuel injection control device for an internal combustion engine. 請求項１に記載の内燃機関の燃料噴射制御装置において、
上記制御部は、上記初期の燃料噴射期間の燃料噴射量をＱ１、上記後期の燃料噴射期間の燃料噴射量をＱ２としたときに、Ｑ１／（Ｑ１＋Ｑ２）を上記アルコール濃度センサが検出したアルコール濃度が高いほど大とすることを特徴とする内燃機関の燃料噴射制御装置。 The fuel injection control device for an internal combustion engine according to claim 1,
The controller controls the alcohol concentration detected by the alcohol concentration sensor as Q1 / (Q1 + Q2) when the fuel injection amount in the initial fuel injection period is Q1 and the fuel injection amount in the latter fuel injection period is Q2. A fuel injection control device for an internal combustion engine, characterized in that the larger the value is, the larger the value is. 請求項２に記載の内燃機関の燃料噴射制御装置において、
上記制御部は、上記初期の燃料噴射期間を、上記アルコール濃度センサが検出したアルコール濃度が高くなるに従って長くし、上記後期の燃料噴射期間を、上記アルコール濃度センサが検出したアルコール濃度が高くなるに従って短くすることにより、上記燃料噴射弁が噴射する混合燃料の噴射量を制御することを特徴とする内燃機関の燃料噴射制御装置。 The fuel injection control device for an internal combustion engine according to claim 2,
The control unit increases the initial fuel injection period as the alcohol concentration detected by the alcohol concentration sensor increases, and the late fuel injection period increases as the alcohol concentration detected by the alcohol concentration sensor increases. A fuel injection control device for an internal combustion engine, wherein the fuel injection amount of the mixed fuel injected by the fuel injection valve is controlled by shortening the fuel injection valve. 請求項２に記載の内燃機関の燃料噴射制御装置において、
上記燃料噴射弁は、弁体のリフト高さを変更して燃料噴射量を変更する燃料噴射弁であり、上記制御部は、上記燃料噴射量Ｑ１及びＱ２を、上記燃料噴射弁の上記弁体のリフト高さを変更することにより変更することを特徴とする内燃機関の燃料噴射制御装置。 The fuel injection control device for an internal combustion engine according to claim 2,
The fuel injection valve is a fuel injection valve that changes a fuel injection amount by changing a lift height of the valve body, and the control unit converts the fuel injection amounts Q1 and Q2 into the valve body of the fuel injection valve. A fuel injection control device for an internal combustion engine, which is changed by changing a lift height of the engine. 請求項２に記載の内燃機関の燃料噴射制御装置において、
上記燃料噴射弁は、上記初期の燃料噴射期間に燃料を噴射する第一の燃料噴射弁と、上記後期の燃料噴射期間に燃料を噴射する第二の燃料噴射弁とであることを特徴とする内燃機関の燃料噴射制御装置。 The fuel injection control device for an internal combustion engine according to claim 2,
The fuel injection valve is a first fuel injection valve that injects fuel during the initial fuel injection period and a second fuel injection valve that injects fuel during the latter fuel injection period. A fuel injection control device for an internal combustion engine. 請求項５に記載の内燃機関の燃料噴射制御装置において、
上記第一の燃料噴射弁に燃料を供給する第一の燃料ポンプと、上記第二の燃料噴射弁に燃料を供給する第二の燃料ポンプとを備え、上記制御部は、上記第一の燃料ポンプと第二の燃料ポンプの燃料噴射圧を変更し、上記第一の燃料噴射弁及び上記第二の燃料噴射弁の燃料噴射量を制御することを特徴とする内燃機関の燃料噴射制御装置。 The fuel injection control device for an internal combustion engine according to claim 5,
A first fuel pump that supplies fuel to the first fuel injection valve; and a second fuel pump that supplies fuel to the second fuel injection valve; and the control unit includes the first fuel pump. A fuel injection control device for an internal combustion engine, wherein fuel injection pressures of the first fuel injection valve and the second fuel injection valve are controlled by changing fuel injection pressures of the pump and the second fuel pump. 請求項６に記載の内燃機関の燃料噴射制御装置において、
上記第一の燃料噴射弁は、単孔式または多孔式の燃料噴射弁であり、上記第二の燃料噴射弁は、スワール式または外開き弁式の燃料噴射弁であることを特徴とする内燃機関の燃料噴射制御装置。 The fuel injection control device for an internal combustion engine according to claim 6,
The internal combustion engine characterized in that the first fuel injection valve is a single-hole or porous fuel injection valve, and the second fuel injection valve is a swirl type or an outward opening type fuel injection valve. Engine fuel injection control device. 請求項２に記載の内燃機関の燃料噴射制御装置において、
上記制御部は、内燃機関の回転速度に従って、Ｑ１／（Ｑ１＋Ｑ２）を変更し、内燃機関の回転速度が大となるに従ってＱ１／（Ｑ１＋Ｑ２）を大きくすることを特徴とする内燃機関の燃料噴射制御装置。 The fuel injection control device for an internal combustion engine according to claim 2,
The control unit in accordance with the rotational speed of the internal combustion engine, changes the Q1 / (Q1 + Q2), the fuel injection of an internal combustion engine, wherein the rotational speed of the internal combustion engine to increase the thus Q1 / (Q1 + Q2) to become large Control device. 請求項２に記載の内燃機関の燃料噴射制御装置において、
上記制御部は、上記燃料噴射弁の燃料噴射圧に従って、Ｑ１／（Ｑ１＋Ｑ２）を変更し、燃料噴射圧が高くなるに従ってＱ１／（Ｑ１＋Ｑ２）を小とすることを特徴とする内燃機関の燃料噴射制御装置。 The fuel injection control device for an internal combustion engine according to claim 2,
The control unit in accordance with the fuel injection pressure of the fuel injection valve, Q1 / (Q1 + Q2) to change the, the internal combustion engine, characterized in that the fuel injection pressure is increased thus to Q1 / a (Q1 + Q2) and sub-fuel Injection control device. ガソリンとアルコールとの混合燃料のアルコール濃度を検出し、
内燃機関の温度を検出し、
上記検出した温度に従って内燃機関が冷機状態であると判断した場合には、内燃機関の吸気行程を複数の燃料噴射期間に分割し、分割した燃料噴射期間の内の初期の燃料噴射期間の燃料噴射量を、上記検出したアルコール濃度が高くなるに従って多くし、上記分割した期間の内の後期の燃料噴射期間の燃料噴射量を、上記検出したアルコール濃度が高くなるに従って少なくして、筒内噴射式の燃料噴射弁が噴射する混合燃料の噴射量を制御すること特徴とする内燃機関の燃料噴射制御方法。 Detect the alcohol concentration of the mixed fuel of gasoline and alcohol,
Detecting the temperature of the internal combustion engine,
When it is determined that the internal combustion engine is in a cold state according to the detected temperature , the intake stroke of the internal combustion engine is divided into a plurality of fuel injection periods, and the fuel injection in the initial fuel injection period among the divided fuel injection periods the amount and number in accordance with the alcohol concentration of the above-mentioned detection is increased, the fuel injection amount of the late fuel injection period of the period and the divided, and decreases as the alcohol concentration above the detection is high, in-cylinder injection type A fuel injection control method for an internal combustion engine, comprising controlling an injection amount of a mixed fuel injected by the fuel injection valve. 請求項１０に記載の内燃機関の燃料噴射制御方法において、
上記初期の燃料噴射期間の燃料噴射量をＱ１、上記後期の燃料噴射期間の燃料噴射量をＱ２としたときに、Ｑ１／（Ｑ１＋Ｑ２）を上記検出したアルコール濃度が高いほど大とすることを特徴とする内燃機関の燃料噴射制御方法。 The fuel injection control method for an internal combustion engine according to claim 10,
When the fuel injection amount in the initial fuel injection period is Q1, and the fuel injection amount in the latter fuel injection period is Q2, Q1 / (Q1 + Q2) is increased as the detected alcohol concentration is higher. A fuel injection control method for an internal combustion engine. 請求項１１に記載の内燃機関の燃料噴射制御方法において、
上記初期の燃料噴射期間を、上記検出したアルコール濃度が高くなるに従って長くし、上記後期の燃料噴射期間を、上記検出したアルコール濃度が高くなるに従って短くすることにより、上記燃料噴射弁が噴射する混合燃料の噴射量を制御することを特徴とする内燃機関の燃料噴射制御方法。 The fuel injection control method for an internal combustion engine according to claim 11,
The initial fuel injection period is lengthened as the detected alcohol concentration is increased, and the latter fuel injection period is shortened as the detected alcohol concentration is increased. A fuel injection control method for an internal combustion engine, wherein the fuel injection amount is controlled. 請求項１１に記載の内燃機関の燃料噴射制御方法において、
上記燃料噴射弁は、弁体のリフト高さを変更して燃料噴射量を変更する燃料噴射弁であり、上記燃料噴射量Ｑ１及びＱ２を、上記燃料噴射弁の上記弁体のリフト高さを変更することにより変更することを特徴とする内燃機関の燃料噴射制御方法。 The fuel injection control method for an internal combustion engine according to claim 11,
The fuel injection valve is a fuel injection valve that changes the fuel injection amount by changing the lift height of the valve body, and the fuel injection amount Q1 and Q2 are set to the lift height of the valve body of the fuel injection valve. A fuel injection control method for an internal combustion engine, characterized by being changed by changing. 請求項１１に記載の内燃機関の燃料噴射制御方法において、
上記燃料噴射弁は、上記初期の燃料噴射期間に燃料を噴射する第一の燃料噴射弁と、上記後期の燃料噴射期間に燃料を噴射する第二の燃料噴射弁とであることを特徴とする内燃機関の燃料噴射制御方法。 The fuel injection control method for an internal combustion engine according to claim 11,
The fuel injection valve is a first fuel injection valve that injects fuel during the initial fuel injection period and a second fuel injection valve that injects fuel during the latter fuel injection period. A fuel injection control method for an internal combustion engine. 請求項１４に記載の内燃機関の燃料噴射制御方法において、
上記内燃機関は、上記第一の燃料噴射弁に燃料を供給する第一の燃料ポンプと、上記第二の燃料噴射弁に燃料を供給する第二の燃料ポンプとを備え、上記第一の燃料ポンプと第二の燃料ポンプの燃料噴射圧を変更し、上記第一の燃料噴射弁及び上記第二の燃料噴射弁の燃料噴射量を制御することを特徴とする内燃機関の燃料噴射制御方法。 The fuel injection control method for an internal combustion engine according to claim 14,
The internal combustion engine includes a first fuel pump that supplies fuel to the first fuel injection valve, and a second fuel pump that supplies fuel to the second fuel injection valve, and the first fuel A fuel injection control method for an internal combustion engine, wherein fuel injection pressures of the first fuel injection valve and the second fuel injection valve are controlled by changing fuel injection pressures of the pump and the second fuel pump. 請求項１５に記載の内燃機関の燃料噴射制御方法において、
上記第一の燃料噴射弁は、単孔式または多孔式の燃料噴射弁であり、上記第二の燃料噴射弁は、スワール式または外開き弁式の燃料噴射弁であることを特徴とする内燃機関の燃料噴射制御方法。 The fuel injection control method for an internal combustion engine according to claim 15,
The internal combustion engine characterized in that the first fuel injection valve is a single-hole or porous fuel injection valve, and the second fuel injection valve is a swirl type or an outward opening type fuel injection valve. Engine fuel injection control method. 請求項１１に記載の内燃機関の燃料噴射制御方法において、
上記内燃機関の回転速度に従って、Ｑ１／（Ｑ１＋Ｑ２）を変更し、内燃機関の回転速度が大となるに従ってＱ１／（Ｑ１＋Ｑ２）を大きくすることを特徴とする内燃機関の燃料噴射制御方法。 The fuel injection control method for an internal combustion engine according to claim 11,
According to the rotation speed of the internal combustion engine, Q1 / (Q1 + Q2) to change the fuel injection control method for an internal combustion engine, wherein the rotational speed of the internal combustion engine to increase the thus Q1 / (Q1 + Q2) to become large. 請求項１１に記載の内燃機関の燃料噴射制御方法において、
上記燃料噴射弁の燃料噴射圧に従って、Ｑ１／（Ｑ１＋Ｑ２）を変更し、燃料噴射圧が高くなるに従ってＱ１／（Ｑ１＋Ｑ２）を小とすることを特徴とする内燃機関の燃料噴射制御方法。 The fuel injection control method for an internal combustion engine according to claim 11,
Accordance fuel injection pressure of the fuel injection valve, Q1 / (Q1 + Q2) to change the, the thus Q1 / fuel injection pressure is increased (Q1 + Q2) fuel injection control method for an internal combustion engine, characterized in that and a small.
JP2013211195A 2013-10-08 2013-10-08 Fuel injection control device and fuel injection control method for internal combustion engine Active JP6113044B2 (en)

Priority Applications (2)

Application Number Priority Date Filing Date Title
JP2013211195A JP6113044B2 (en) 2013-10-08 2013-10-08 Fuel injection control device and fuel injection control method for internal combustion engine
PCT/JP2014/075775 WO2015053101A1 (en) 2013-10-08 2014-09-29 Internal-combustion-engine fuel-injection control device and fuel-injection control method

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP2013211195A JP6113044B2 (en) 2013-10-08 2013-10-08 Fuel injection control device and fuel injection control method for internal combustion engine

Publications (2)

Publication Number Publication Date
JP2015075023A JP2015075023A (en) 2015-04-20
JP6113044B2 true JP6113044B2 (en) 2017-04-12

Family

ID=52812920

Family Applications (1)

Application Number Title Priority Date Filing Date
JP2013211195A Active JP6113044B2 (en) 2013-10-08 2013-10-08 Fuel injection control device and fuel injection control method for internal combustion engine

Country Status (2)

Country Link
JP (1) JP6113044B2 (en)
WO (1) WO2015053101A1 (en)

Families Citing this family (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US9915215B2 (en) 2016-04-28 2018-03-13 Caterpillar Inc. Fuel injector for pulsed injections and system and method thereof
JP6670718B2 (en) 2016-09-28 2020-03-25 日立オートモティブシステムズ株式会社 Control device
KR102406145B1 (en) * 2017-05-22 2022-06-08 현대자동차 주식회사 Method and system for controlling injection of mixed fuel in an internal combustion engine
JP2023005304A (en) * 2021-06-28 2023-01-18 日立Astemo株式会社 Internal combustion engine control device

Family Cites Families (11)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH01240763A (en) * 1988-03-18 1989-09-26 Mitsubishi Heavy Ind Ltd Fuel injection valve
JP3924949B2 (en) * 1998-09-02 2007-06-06 株式会社デンソー Fuel injection nozzle
JP2001214744A (en) * 2000-02-03 2001-08-10 Toyota Motor Corp Cylinder injection type spark ignition internal combustion engine
JP2008223676A (en) * 2007-03-14 2008-09-25 Toyota Motor Corp Fuel injection control device for cylinder injection type engine
JP2008255907A (en) * 2007-04-05 2008-10-23 Toyota Motor Corp Fuel injection control device for cylinder injection engine
JP2008261231A (en) * 2007-04-10 2008-10-30 Toyota Motor Corp Fuel injection control device of cylinder injection type engine
JP2008267274A (en) * 2007-04-20 2008-11-06 Toyota Motor Corp Control system for direct injection engine
JP2009047055A (en) * 2007-08-17 2009-03-05 Toyota Motor Corp Internal combustion engine
JP2009062862A (en) * 2007-09-06 2009-03-26 Toyota Motor Corp Fuel injection control device of internal combustion engine
JP2011247110A (en) * 2010-05-24 2011-12-08 Toyota Motor Corp Control device of internal combustion engine
JP5837849B2 (en) * 2012-03-21 2015-12-24 日立オートモティブシステムズ株式会社 In-cylinder injection engine control device

Also Published As

Publication number Publication date
WO2015053101A1 (en) 2015-04-16
JP2015075023A (en) 2015-04-20

Similar Documents

Publication Publication Date Title
US7894973B2 (en) Method and device for operating an internal combustion engine
US10436134B2 (en) Control device for internal combustion engine
JP6113044B2 (en) Fuel injection control device and fuel injection control method for internal combustion engine
JP2007009815A (en) Control device for internal combustion engine
JP5781855B2 (en) Spray characteristic estimation device
JP5968771B2 (en) Fuel injection control device for internal combustion engine
US20100147261A1 (en) Gasoline engine
US20130192562A1 (en) Fuel injection control device and fuel injection method for internal combustion engine
JP2008208813A (en) Fuel injection valve of internal combustion engine, control method of fuel injection valve, control circuit device of fuel injection valve, and fuel injection device of direct fuel injection type internal combustion engine
CN109328263B (en) Control device
US20180010510A1 (en) Control device for internal combustion engine
CN107407223B (en) Fuel injection control device for direct injection engine
EP3460223A1 (en) Internal combustion engine control device
JP2009185687A (en) Direct-injection spark-ignition internal combustion engine
JP2008255907A (en) Fuel injection control device for cylinder injection engine
WO2015151945A1 (en) Controller for internal combustion engine
US8752529B2 (en) Spark ignition internal combustion engine
US20210293200A1 (en) Internal Combustion Engine Control Device, and Fuel Injection Valve
US20190040814A1 (en) Fuel Injection Valve Control Device
JP5837849B2 (en) In-cylinder injection engine control device
JP2011247110A (en) Control device of internal combustion engine
JP2011236834A (en) Fuel injection device
US9194323B2 (en) Fuel injection device
JPH0996241A (en) Combustion device for diesel engine
JP5803792B2 (en) Fuel injection device

Legal Events

Date Code Title Description
A621 Written request for application examination

Free format text: JAPANESE INTERMEDIATE CODE: A621

Effective date: 20160308

RD02 Notification of acceptance of power of attorney

Free format text: JAPANESE INTERMEDIATE CODE: A7422

Effective date: 20160308

A131 Notification of reasons for refusal

Free format text: JAPANESE INTERMEDIATE CODE: A131

Effective date: 20160906

A521 Request for written amendment filed

Free format text: JAPANESE INTERMEDIATE CODE: A523

Effective date: 20161027

TRDD Decision of grant or rejection written
A01 Written decision to grant a patent or to grant a registration (utility model)

Free format text: JAPANESE INTERMEDIATE CODE: A01

Effective date: 20170307

A61 First payment of annual fees (during grant procedure)

Free format text: JAPANESE INTERMEDIATE CODE: A61

Effective date: 20170314

R150 Certificate of patent or registration of utility model

Ref document number: 6113044

Country of ref document: JP

Free format text: JAPANESE INTERMEDIATE CODE: R150

S533 Written request for registration of change of name

Free format text: JAPANESE INTERMEDIATE CODE: R313533

R350 Written notification of registration of transfer

Free format text: JAPANESE INTERMEDIATE CODE: R350

R250 Receipt of annual fees

Free format text: JAPANESE INTERMEDIATE CODE: R250