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
  • F02D41/009—Electrical control of supply of combustible mixture or its constituents using means for generating position or synchronisation signals
• • 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
  • F02P15/00—Electric spark ignition having characteristics not provided for in, or of interest apart from, groups F02P1/00 - F02P13/00 and combined with layout of ignition circuits
  • F02P15/08—Electric spark ignition having characteristics not provided for in, or of interest apart from, groups F02P1/00 - F02P13/00 and combined with layout of ignition circuits having multiple-spark ignition, i.e. ignition occurring simultaneously at different places in one engine cylinder or in two or more separate engine cylinders
• • 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
  • F02P17/12—Testing characteristics of the spark, ignition voltage or current
• • 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
  • F02P7/00—Arrangements of distributors, circuit-makers or -breakers, e.g. of distributor and circuit-breaker combinations or pick-up devices
  • F02P7/02—Arrangements of distributors, circuit-makers or -breakers, e.g. of distributor and circuit-breaker combinations or pick-up devices of distributors
  • F02P7/03—Arrangements of distributors, circuit-makers or -breakers, e.g. of distributor and circuit-breaker combinations or pick-up devices of distributors with electrical means
  • F02P7/035—Arrangements of distributors, circuit-makers or -breakers, e.g. of distributor and circuit-breaker combinations or pick-up devices of distributors with electrical means without mechanical switching means
• • 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
  • F02B1/00—Engines characterised by fuel-air mixture compression
  • F02B1/02—Engines characterised by fuel-air mixture compression with positive ignition
  • F02B1/04—Engines characterised by fuel-air mixture compression with positive ignition with fuel-air mixture admission into cylinder
• • 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
  • F02P17/12—Testing characteristics of the spark, ignition voltage or current
  • F02P2017/125—Measuring ionisation of combustion gas, e.g. by using ignition circuits

Definitions

• the present invention relates generally to synchronisation devices without cam-position sensors for combustion engines, particularly internal combustion engines for motor vehicles.
• the object of the present invention is to provide a synchronisation device which enables all the problems indicated above to be resolved satisfactorily.
• the essential idea on which the present invention is based is that of using an engine reference angle of 360° as the precise reference and of discriminating between odd and even 360° phases of a reference cylinder (which may be any one of the engine's cylinders) by using signals already available to the electronic engine management unit.
• Ionisation detection circuits supply a signal proportional (in duration or amplitude) to the duration of the spark.
• the voltage for triggering and maintaining the combustion varies widely according to the pressure in the combustion chamber of the cylinder (approximately proportional to this) while the arc current of the spark is about constant. This means that, for a given energy supplied to the primary winding of the coil (for a given coil efficiency) the duration of the spark varies considerably.
• the spark lasts for a normal period of time if the cylinder is in compression while it lasts much longer if the cylinder is in the exhaust stroke.
• the strategy explained above may be improved to increase the certainty of discrimination by using several different cylinders as successive references (still during the first revolution of the engine and possibly fractions of the next revolution).
• the additional information thus obtained may confirm the first result or indicate the need for further monitoring if the results do not agree.
• the strategy may be carried out by using other signals which may be available to the engine's electronic management unit.
• One signal which is always available, or can be deduced, is typically the correlation of the engine acceleration (positive or negative) with the throttle valve angle.
• This information can well be used in symmetrical engines instead of the said signal indicative of ionisation.
• a four- or six-cylinder engine with pairs of cylinders out of phase by 360° (or even by 370-380°) is considered.
• the engine may be started with two half-injections of fuel into almost opposed cylinders and with almost simultaneous firing of their ignitions.
• ignitions are lost in the cylinder on the exhaust stroke but these ignitions (with the valve timing overlap typical of engines in current production) are not harmful. In these conditions the engine starts effectively.
• throttle valve angle greater than ⁇ O which corresponds, in practice, to a specific required torque, with the engine already started (rotational speed greater than Y revolutions/sec for given ⁇ O and Y)
• a search strategy may be undertaken to effect discrimination between even and odd 360° angles.
• This strategy may comprise effecting ignition every 720° for all cylinders, with a random choice of association with the 720° reference, that is, a random choice between even 360° angles and odd 360° angles. If the engine decelerates beyond a predetermined limit, the opposite association is tested, that is the choice between even 360° angles and odd 360° angles is reversed. At the end of this test, the correct reference is thus identified.
• This strategy may cause a gap in the engine operation but this situation is not dangerous and is scarcely perceptible to the driver since the engine is being started.
• a strategy for recognising the even 360° angles and odd 360° angles may be carried out independently of the position of the throttle valve when the engine is in the transitional stage between the disconnection of the starter motor and the attainment of idling conditions (about 400-600 revolutions per minute).
• both the injection and the ignition are controlled with the use of all this information (thus injection may be phased). Even then, one of the above-mentioned strategies may possibly be repeated with the engine running should the engine speed drop inexplicably.
• Another source of information which can be used to determine the 720° phase reference is provided by pressure sensors in the cylinder, if these are present, since these enable direct determination of whether the reference cylinder is in compression or exhaust.

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)
• Ignition Installations For Internal Combustion Engines (AREA)

Applications Claiming Priority (2)

Publications (3)

Family

ID=11412795

Family Applications (1)

Country Status (4)

Cited By (6)

Families Citing this family (1)

Family Cites Families (6)

• 1994
  • 1994-09-30 IT IT94TO000766A patent/IT1268605B1/it active IP Right Grant
• 1995
  • 1995-09-28 DE DE69532493T patent/DE69532493T2/de not_active Expired - Lifetime
  • 1995-09-28 ES ES95115292T patent/ES2211891T3/es not_active Expired - Lifetime
  • 1995-09-28 EP EP95115292A patent/EP0704621B1/de not_active Expired - Lifetime

Non-Patent Citations (1)

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