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
  • F02D41/30—Controlling fuel injection
  • F02D41/32—Controlling fuel injection of the low pressure type
  • F02D41/34—Controlling fuel injection of the low pressure type with means for controlling injection timing or duration
  • F02D41/345—Controlling injection timing
• • 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
  • F02D41/18—Circuit arrangements for generating control signals by measuring intake air flow
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
  • Y02T—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO TRANSPORTATION
  • Y02T10/00—Road transport of goods or passengers
  • Y02T10/10—Internal combustion engine [ICE] based vehicles
  • Y02T10/40—Engine management systems

Definitions

• the amount of fuel to be injected is essentially formed from the quotient of the intake air mass and the speed.
• the air mass is measured in the air intake pipe and not directly in front of the intake manifold of the cylinder. If the intake pipe volume / displacement ratio is greater than two, this often results in unstable idling, which is due to the fact that the air mass , which is used to determine the amount of fuel to be injected, does not correspond to the air mass actually available in the intake stroke. The reason for this is that the air takes a finite time to cover the distance between the air mass sensor and the inlet valve.
• the invention is based on an arrangement for obtaining signals for the control unit of an electronic fuel injection. From DE-OS 24 55 482 an arrangement is known in which the analog signals from the engine speed sensor and the air measuring device are fed to a smoothing device with a low-pass character in order to dampen and smooth the AC voltage components that may occur in the analog voltage signals as a result of unintended influences.
• the object of the invention is to compensate for the phase shift resulting from finite running times of the air in the intake pipe and to counteract their influence on the idling of the internal combustion engine.
• the fuel metering device according to the invention with the characterizing features of the main claim has the advantage over the prior art of compensating for phase-related phase shifts of almost any size without the useful signal being damped, which means e.g. the susceptibility to failure is increased.
• the measures listed in the subclaims are advantageous, sometimes simpler developments of the fuel metering device specified in the main claim.
• the measures listed in the subclaim provide the possibility of using the device according to the invention in already existing control devices.
• FIG. 1 shows schematically the path causing the running time of the air between the air quantity / mass sensor in the intake pipe and the intake manifold
• FIG. 2 shows the signal generated by the air mass sensor and a signal corresponding to the air mass present on the intake manifold
• FIG. 3 shows the one for compensation
• the devices in the control device required for the runtime effects and some sensors connected to the control device
• FIG. 4 shows an embodiment of the phase shifter with the aid of low-pass filters with different rise times
• FIG. 5 deals with the possibility of compensating for runtime effects in the case of control devices already present.
• 10 denotes an internal combustion engine
• 11 denotes an intake manifold, through which the air mass sucked in through the intake pipe 14 is fed to the inlet valves of the internal combustion engine.
• An air mass / quantity sensor is designated by 12.
• air mass is used, also representative of the amount of air. It is generally known in what way the corresponding air mass signal is obtained from an air quantity signal.
• the air mass Q is plotted against time t. 20 identifies the air mass signal emitted by the air mass sensor 12, while 21 represents a signal shifted by the time t: (22), which corresponds to the air mass present on the intake manifold. Since the amount of fuel Q supplied to the internal combustion engine from the
• 30 denotes a part of the functions implemented in an electronic control unit.
• the signal 1 / n is formed from the signal of the speed sensor 34.
• 32 denotes a phase shifter, 33 a multiplication stage and 35 the air mass sensor.
• the sensors 36 for the machine temperature and 37 for the temperature of the intake air mass represent other possible sensors.
• Output lines of multiplication stage 33 are identified by 38 and 38a, and 39 the output line of the phase shifter.
• the described device according to FIG. 1 operates as follows:
• the signals from sensors 34, 35, 36 and 37 are fed to control unit 30.
• the compensation of the Lau time effects primarily affects the air mass signal 35, but can also be applied to the speed signal. For this reason, the processing of the other sensor signals (36, 37) is not considered below.
• the reciprocal value is formed in the device 31 from the speed signal.
• the air mass signal is fed to the phase shifter 32 known per se, which causes a delay of this signal which is dependent on the air mass sucked in.
• the output signal of the phase shifter reaches the multiplier 33 via line 39, in which it is multiplied by the reciprocal of the signal corresponding to the speed.
• a fuel quantity signal is available on line 38, with which a fuel metering device can be controlled. In the case of intermittently operating fuel injection, an output signal in the form of an injection duration is also conceivable (line 38a).
• the mode of operation of the runtime compensation shown and described here on the basis of individual blocks is of course not limited to control units with analog signal processing, but is also representative of each digitally working version of such a device.
• the air mass signal determined by the air mass sensor 12 reaches a threshold value stage 43 and a switch 44 via the line 35. With the aid of the switch, this signal is switched to a low-pass filter 41 and the other to a low-pass filter 42.
• Switch 45 connects via line 39 the output signal of the low-pass filter to a multiplier 33, the output signal of which is fed to a modulator stage 46.
• An injection duration corresponding to a quantity of fuel is available at the outlet thereof.
• the threshold level 43 brings the switches 44 and 45 into such a position when the air mass flow is less than, for example, 32 kg per hour that the air mass signal is fed to the low-pass filter 42, which for example has a rise time of 200 ms.
• the phase-shifted air mass signal is multiplied by the reciprocal 1 / n of the speed signal, which results in a fuel quantity signal.
• this signal is fed to the modulator 46, which e.g. converted into a pulse length modulated injection duration.
• the output signal of the modulator 46 is then used to control an output stage, which is not designated in any more detail and which supplies the current for operating the fuel injection device (solenoid valves).
• the arrangement according to FIG. 4 is a realization of a phase shifter that is dependent on the air mass flow and is produced using simple means.
• a first injection duration determined from the signals speed and air mass sucked in, reaches a multiplier 52 via a line 51.
• This signal which may have disruptive runtime effects, is converted back into the original air mass signal by multiplying it by the speed n ⁇ changes.
• This signal is fed to a phase shifter 50 to compensate for the runtime effects.
• a second injection duration 54 is determined, which, as already mentioned above, is then processed further.

Landscapes

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

Priority Applications (1)

Applications Claiming Priority (2)

Publications (1)

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ID=6308193

Family Applications (1)

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Citations (5)

• 1986
  • 1986-08-26 DE DE19863628962 patent/DE3628962A1/de not_active Withdrawn
• 1987
  • 1987-07-22 WO PCT/DE1987/000328 patent/WO1988001686A1/de unknown
• 1988
  • 1988-04-25 KR KR1019880700446A patent/KR880701821A/ko not_active Application Discontinuation

Patent Citations (5)

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