Classifications

• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
  • F02P—IGNITION, OTHER THAN COMPRESSION IGNITION, FOR INTERNAL-COMBUSTION ENGINES; TESTING OF IGNITION TIMING IN COMPRESSION-IGNITION ENGINES
  • F02P17/00—Testing of ignition installations, e.g. in combination with adjusting; Testing of ignition timing in compression-ignition engines
  • F02P17/02—Checking or adjusting ignition timing
  • F02P17/04—Checking or adjusting ignition timing dynamically
• • 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
  • F02D41/24—Electrical control of supply of combustible mixture or its constituents characterised by the use of digital means
  • F02D41/26—Electrical control of supply of combustible mixture or its constituents characterised by the use of digital means using computer, e.g. microprocessor
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
  • F02P—IGNITION, OTHER THAN COMPRESSION IGNITION, FOR INTERNAL-COMBUSTION ENGINES; TESTING OF IGNITION TIMING IN COMPRESSION-IGNITION ENGINES
  • F02P5/00—Advancing or retarding ignition; Control therefor
  • F02P5/04—Advancing or retarding ignition; Control therefor automatically, as a function of the working conditions of the engine or vehicle or of the atmospheric conditions
  • F02P5/145—Advancing or retarding ignition; Control therefor automatically, as a function of the working conditions of the engine or vehicle or of the atmospheric conditions using electrical means
  • F02P5/15—Digital data processing
  • F02P5/1502—Digital data processing using one central computing unit
  • F02P5/151—Digital data processing using one central computing unit with means for compensating the variation of the characteristics of the engine or of a sensor, e.g. by ageing
• • 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

• This invention relates to the adjustment or 'tuning' of internal combustion engines.
• an apparatus for adjustment of an internal combustion engine comprising means for generating a performance signal representative of the angular acceleration of the engine in response to an acceleration test, means for effecting adjustment of at least one engine control and control means arranged in operation to carry out an adjustment sequence comprising: initiating an acceleration test; comparing the performance signal with a predetermined value; and, if the comparison indicates that the acceleration is less than the predetermined value, carrying out the further steps of adjusting the engine control in one sense, repeating the acceleration test and comparing the performance signal with a stored value of the performance signal previously measured to determine the sense for further adjustment, and repeating the steps of adjustment, test and comparison as necessary until the performance signal attains the predetermined value or the adjustment sequence is terminated. Where more than one control is to be adjusted, the sequence is carried out in respect of each such control.
• FIG. 1 is a block diagram of an adjustment apparatus embodying the invention
• Figure 2 is a flow chart showing the sequence of operation of the apparatus of Figure 1;
• FIGS 3 and 4 are flow charts showing in more detail certain of the steps shown in Figure 2.
• a microprocessor has input ports connected to a tachometer 2, and start button 3. Output ports control ignition timing circuitry 4 and fuel injection control 5.
• the apparatus should not be employed to control systems using mechanical ignition and/or a carburettor it is assumed that electronic ignition and fuel injection are employed and, indeed, the test arrangement described here can be particularly conveniently employed in cases where microprocessor fuel injection is already employed (as described in our co-pending International application PCT/GB82/00199).Although the apparatus could be used as a remote service tool, it is assumed to be permanently installed in.
• the microprocessor may also serve for other engine and vehicle management and control functions although these form no part of the present invention and will not be described here. Further output ports of the microprocessor drive indicator lamps 6, 7,8 which serve respectively to request the driver to depress the throttle, to indicate that the tune is complete, and to signal the necessity for a service.
• the principle of operation of the apparatus is that, when, with the engine at working temperature and at tickover, it is instructed to carry out a tuning procedure, it will firstly carry out a test to establish whether the performance of the engine meets a pre-set standard. It instructs the driver to open the throttle, and establishes the comparative efficiency of the engine by measuring the time taken to accelerate the engine from tickover. or a somewhat higher speed, to a predetermined point in the engine speed range as measured by the tachometer 2 - i.e., the time taken to overcome the inertia of the moving parts - this providing a measure of the acceleration of the engine. This is compared with a standard time previously established by the engine manufacture and stored in the microprocessor memory.
• the first run will indicate whether the performance meets the set standard, and, if so, the driver is informed "tune complete” and no further action is taken. If the performance is below this limit, the apparatus carries out further tests, making variations in ignition timing and fuelling, to optimise these variables, as will be further described below. If the test sequence fails to result in the expected performance, the driver is informed that a service is required, to identify other adjustments or faults requiring attention.
• test sequence is indicated in Figure 2 as a flow chart. It is assumed that it is entered at 10 from a sequence including other control functions carried out by the microprocessor. If (11) "tune" mode has been selected, i.e. the start button 3 has been depressed, a test sequence is commenced.
• the test can be carried out at any time, although, in a preferred arrangement the apparatus can be arranged to provide visual warning to the driver that tuning is due, when a predetermined time (in terms of so many miles or engine revolutions) has elapsed since the last adjustment.
• a test (12) is then initiated, as detailed in Figure 3.
• the light 6 is illuminated (20) to instruct the driver to open the throttle, and a wait sequence 21 is entered until the engine speed as measured by the tachometer is rising, and (22) reaches 2000 r.p.m.
• the time (T) is then measured (23) for the speed to reach 5000, and T is stored (24).
• a check 25 is made for an engine speed greater than say 6000 r.p.m. and if this occurs, the ignition is cut (26) until the speed falls below this figure. This check continues until (27) the throttle angle is less than 10o - i.e. the driver has released the throttle.
• the ignition is then reinstated (28).
• the time T 1 for the first test is compared (13) with the reference time T N (times for successive tests are designated (T 1 ,T 2 , ....T x .etc). If the time is less than or equal to the reference, the "tune complete" indicator 7 is illuminated (14). Otherwise an adjustment sequence 15 is entered, following which it is checked whether (16) the time is now less than or equal to the standard T N , whereupon the sequence is terminated: otherwise the adjust sequence is repeated, unless (17) the number of tests has exceeded a predetermined maximum. In this case the tuna is abandoned, as it is assumed that there is a mechanical fault, and the driver is instructed, by illuminating (18) the warning light 8, that a service is required.
• One possible adjustment sequence 14 is shown in Figure 4.
• the test is then run (33) to establish the time (T x ) for the new setting (the test sequence being as in Figure 3).
• the time is then compared (34) with the previous time, to see if an improvement has occurred. If it has, or there is no change, the sequence is repeated (35) to advance the ignition timing further, until a deterioration in performance is noted, whereupon the sequence is repeated with Q negative, to retard the ignition timing until again a deterioration is noted. As this implies that the ignition has been retarded too far, it is advanced again (36), to the optimum.
• the apparatus searches on both sides of the existing ignition timing setting, to find a minimum in T x .
• the test of Q (37) serves to identify the end of the second run round the loop.
• the apparatus could also be arranged to display the figures measured, as acceleration times, or converted to an efficiency or horsepower figure, plus the actual ignition and fuel settings. These could be displayed digitally, and in the case of an external unit a printed record could also be made available.

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• Engineering & Computer Science (AREA)
• Chemical & Material Sciences (AREA)
• Combustion & Propulsion (AREA)
• Mechanical Engineering (AREA)
• General Engineering & Computer Science (AREA)
• Theoretical Computer Science (AREA)
• Signal Processing (AREA)
• Computer Hardware Design (AREA)
• Microelectronics & Electronic Packaging (AREA)
• Combined Controls Of Internal Combustion Engines (AREA)
• Electrical Control Of Ignition Timing (AREA)

Applications Claiming Priority (2)

Publications (1)

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ID=10528119

Family Applications (1)

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Family Cites Families (6)

• 1983
  • 1983-02-04 WO PCT/GB1983/000030 patent/WO1983002803A1/en unknown
  • 1983-02-04 EP EP83900645A patent/EP0101463A1/de not_active Withdrawn

Non-Patent Citations (1)

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