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
  • F02D—CONTROLLING COMBUSTION ENGINES
  • F02D41/00—Electrical control of supply of combustible mixture or its constituents
  • F02D41/02—Circuit arrangements for generating control signals
  • F02D41/04—Introducing corrections for particular operating conditions
  • F02D41/12—Introducing corrections for particular operating conditions for deceleration
  • F02D41/123—Introducing corrections for particular operating conditions for deceleration the fuel injection being cut-off
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
  • F02D—CONTROLLING COMBUSTION ENGINES
  • F02D41/00—Electrical control of supply of combustible mixture or its constituents
  • F02D41/02—Circuit arrangements for generating control signals
  • F02D41/14—Introducing closed-loop corrections
  • F02D41/1497—With detection of the mechanical response of the engine
• • 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
  • F02D2200/0612—Fuel type, fuel composition or fuel quality determined by estimation
• • 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
  • F02D2200/1002—Output torque

Definitions

• the invention relates to an engine fuel property estimation apparatus that injects fuel at the time of engine fuel cut and that estimates the ignition quality of the fuel from the engine torque produced by combustion of the injected fuel.
• a second aspect of the invention provides an engine fuel property estimation apparatus that injects fuel of an engine at a time of fuel cut of the engine and that estimates ignition quality of the fuel from magnitude of engine torque produced by combustion of the fuel injected.
• vehicle speed at a time of estimating the ignition quality of the fuel is a first speed
• the estimation apparatus causes an upper limit value of engine rotation speed for implementing a fuel injection for estimating the ignition quality of the fuel to be smaller than when the vehicle speed at the time of estimation of the ignition quality is a second speed that is lower than the first speed.
• the deterioration of the accuracy of the estimation due to variations of the cylinder wall temperature can be restrained by lessening the upper limit value of the engine rotation speed for implementing the fuel injection for estimating the ignition quality of the fuel.
• the upper limit value of the engine rotation speed for implementing the fuel injection for estimating the ignition quality of the fuel is lessened. Therefore, the deterioration of the estimation accuracy due to variations of the cylinder wall temperature is restrained, so that the ignition quality of the fuel can be estimated with improved accuracy.
• FIG. 6 is a graph showing a relation between the upper-limit intake air temperature and the vehicle speed in the embodiment
• Each of the thus-constructed injectors 16 operates as follows.
• the pressure-electric actuator 39 when not energized with drive voltage, assumes a contracted state in which the entire length of the pressure-electric actuator 39 is reduced, so as to position the valve body 40 at such a position that the pressure chamber 34 communicates with the communication passageway 37 and is shut off from the discharge passageway 38.
• the nozzle chamber 33 and the pressure chamber 34 communicate with each other, so that the pressures in the two chambers are substantially equal. Therefore, at this time, the needle valve 31 has been disposed downward in FIG. 2 by the spring force of the spring 32 so that the injection holes 35 are closed. Hence, at this time, fuel is not injected from the injector 16.
• the electronic control unit 19 finds the rate of change of the fuel pressure (the time derivative of the fuel pressure) within each injector 16, and finds the aforementioned timings on the basis of the value of the rate of change.
• step SI 02 it is determined whether the present engine rotation speed NE is less than or equal to the upper-limit rotation speed NEmax and the present intake air temperature THA is less than or equal to the upper-limit intake air temperature THAmax. If the present engine rotation speed NE is greater than the upper-limit rotation speed NEmax or the present intake air temperature THA is greater than the upper-limit intake air temperature THAmax (NO), the present process immediately ends. On the other hand, if the present engine, rotation speed NE less than or equal to the upper-limit rotation speed NEmax and the present intake air temperature THA is less than or equal to the upper-limit intake air temperature THAmax (YES), the process proceeds to step S I 03.
• FIG. 8 An upper section of FIG. 8 shows transition of the engine rotation speed before and after execution of the fuel injection for detection of the cetane number, and a lower section of FIG. 8 shows transition of the rotation speed difference ⁇ at that time.
• the engine rotation speed increases or the rate of decrease in the engine rotation speed decreases, so that the rotation speed difference ⁇ increases.
• the time integrated value of the increase in the rotation speed difference ⁇ (which corresponds to the area of a hatched portion in FIG. 8) is larger as the produced torque is larger. Therefore, in this embodiment, the time integrated value of the increase in the rotation speed difference ⁇ is calculated as an amount of change in rotation ⁇ , and the value of the amount is used as an index value of the produced torque.
• the produced torque is larger, so that the amount of change in rotation ⁇ is more greatly reduced for correction. Furthermore, as the injection amount error to the side of increased amount is larger, the produced torque is larger, so that the amount of change in rotation ⁇ is more greatly reduced for correction.
• the estimation of the cetane number of the fuel in the ordinary mode is performed.
• the injection of a small amount of fuel for cetane number estimation is implemented at the time point at which the engine rotation speed NE decreases to or below the upper-limit rotation speed NEmax calculated on the basis of the vehicle speed.
• the value of the upper-limit rotation speed NEmax is made smaller as the vehicle speed SPD is higher, that is, as the engine load prior to the fuel cut is estimated to be higher. Therefore, when the vehicle speed SPD is high, the engine rotation speed needs to decrease to a lower rotation speed in order for the fuel injection for cetane number estimation to be implemented than when the vehicle speed SPD is low.
• the amount of fuel actually injected is found from change in the fuel pressure within an injector 16 detected by the fuel pressure sensor 17, and the found amount of fuel actually injected is fed back to the drive control of the injectors.
• the estimation of the cetane number (ignition quality of the fuel) in the foregoing embodiment can be applied in the same manner to a diesel engine that does not perform the above-described feedback.

Landscapes

• Engineering & Computer Science (AREA)
• Chemical & Material Sciences (AREA)
• Combustion & Propulsion (AREA)
• Mechanical Engineering (AREA)
• General Engineering & Computer Science (AREA)
• Combined Controls Of Internal Combustion Engines (AREA)
• Electrical Control Of Air Or Fuel Supplied To Internal-Combustion Engine (AREA)

Priority Applications (2)

Applications Claiming Priority (2)

Publications (2)

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ID=48095930

Family Applications (1)

Country Status (4)

Cited By (3)

Families Citing this family (2)

Citations (1)

Family Cites Families (14)

• 2012
  • 2012-03-30 JP JP2012080961A patent/JP5880219B2/ja not_active Expired - Fee Related
• 2013
  • 2013-03-11 CN CN201380017266.0A patent/CN104220733B/zh not_active Expired - Fee Related
  • 2013-03-11 DE DE112013001817.9T patent/DE112013001817T5/de not_active Ceased
  • 2013-03-11 WO PCT/IB2013/000355 patent/WO2013144694A2/fr not_active Ceased

Patent Citations (1)

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