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
  • F02P17/12—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
  • F02D—CONTROLLING COMBUSTION ENGINES
  • F02D35/00—Controlling engines, dependent on conditions exterior or interior to engines, not otherwise provided for
  • F02D35/02—Controlling engines, dependent on conditions exterior or interior to engines, not otherwise provided for on interior conditions
  • F02D35/021—Controlling engines, dependent on conditions exterior or interior to engines, not otherwise provided for on interior conditions using an ionic current sensor
• • 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
  • F02D41/28—Interface circuits
• • 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
  • F02P5/153—Digital data processing dependent on combustion 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
  • F02D41/24—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
  • F02D41/28—Interface circuits
  • F02D2041/286—Interface circuits comprising means for signal processing
• • 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
  • F02D2200/1004—Estimation of the output torque
• • 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
  • F02D2200/1015—Engines misfires
• • 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
• • 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
  • F02P2017/128—Measuring ionisation of combustion gas, e.g. by using ignition circuits for knock detection
• • 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 present invention relates to a method more closely specified in accordance with the preamble of claim 1.
• Combustion engines are desirably designed in order to extract maximum obtainable work for each amount of fuel supplied.
• the start of combustion should take place at a point of time such that the combustion pressure is optimised with respect to amplitude and crankshaft position, obtaining maximum positive torque from the combustion engine.
• US,A,4417556 is previously known a method wherein the pressure peak position from the combustion is detected, using an ionisation sensor in the combustion chamber. The peak position of the ionisation current is argued to coincide with the position of the peak position of the combustion pressure.
• An object of the invention is, for a combustion engine having a measure gap arranged in the combustion chamber detecting ionisation current in the combustion chamber, which measure gap preferably consist of the spark plug gap of the combustion engine, utilising the ionisation current in the combustion chamber as a parameter representative of the cylinder pressure, and obtaining a more reliable ignition timing control dependent of the detected ionisation current.
• Another object is to obtain a method for ignition timing control adapted for mass produced Otto engines, which engines cause comparatively large variations between successive combustion's, where the sign of the first order derivative of the ion current could change several times during the so called post ionisation phase due to unstable combustion.
• Yet another object is to enable a feed back control of the ignition timing adapted for each individual engine and the conditions of the individual engine, obtaining optimum ignition timing.
• the inventive method is basically characterised by the characterising clause of claim 1.
• a parameter representative of the ion current By using an integrated value of a parameter representative of the ion current, is a method obtained for ignition timing control applicable for an increased number of operating cases.
• the value based on the integrated value is considerably more insensitive for short fluctuations of the ion current signal, which fluctuations often occur at low speeds(revs) and low load when the combustion is rather unstable from one combustion to another combustion.
• Use of the ionisation current for controlling the ignition timing could hence be applied in vehicle engines, which engines are subjected to large variations in speed and load, with a larger degree of reliability and larger regulating range within the operating range of the combustion engine.
• a first alternative method characterised by the characterising clause of claim 2 is the calculated mass centre of the integral used as base for control of the ignition timing.
• the mass centre of the integral corresponds to the pressure peak position of the combustion for an increased number of speed- and load ranges.
• a second alternative method characterised by the characterising clause of claim 4 is an integration used where also the mechanics of the combustion engine is a factor in the integration, in order to determine a representative integrated value of the torque transmitted to the crankshaft. Optimising this value result in a corresponding optimisation of the torque obtained.
• Figure 1 shows schematically a capacitive type of ignition system having an inventive arrangement for carrying out the inventive method
• Figure 2 shows the geometry of the combustion engine, which geometry is of use in an alternative embodiment in order to optimise the torque transmitted to the crankshaft dependent of the mechanics
• Figure 3 shows an alternative embodiment of the second optimising control circuit
• Figure 4 shows an idealised representation of the relationship between the ion current and the cylinder pressure.
• the ignition system principally illustrated in figure 1 is of the same capacitive type as shown in EP,B,188180 and SE,C,457831, and is applicable to a multi-cylinder ,Otto-type engine, although only two of the spark plugs 2,3 intended for the cylinders of the engine cylinders have been shown.
• a charging circuit 4 obtaining voltage supply from a low voltage source 5, e.g. a 12 volt battery. After transforming up, the charging circuit 4 supplies a voltage of approximately 400 volts to a line 10, to which there is also connected a wire 11 to a charging capacitor 15, in turn connected to ground.
• This capacitor is thus charged to about 400 volts and is in communication via line 10 with primary windings 12,13, coupled in parallel, of a number of ignition coils corresponding to the number of engine cylinders.
• Each primary winding 12, 13 is connected to a circuit 20,21 respectively, which circuit is in turn connected to ground across a thyristor 22,23, respectively.
• the thyristors 22,23 can open the ground connection 20,21 of the primary windings 12,13, respectively, the lines 24,25 coming from an ignition timing unit 6, hereinafter designated timing unit.
• the latter receives on lines 7,8,9,64 input signals relating to engine revolutions, load, crankshaft angular position and engine temperature, and generates, after processing said signals in a microcomputer-based system incorporated in the timing unit, output signals in response to said input signals.
• the capacitor When the ground connection of the primary windings 12,13 opens as a consequence of a timing signal being sent to the thyristor 22,23 respectively, the capacitor is discharged to ground via the line 20,21 respectively.
• the appropriate primary winding then induces a high ignition voltage (about 40 kVolt) in its corresponding secondary winding 30,31 respectively.
• the secondary winding is included in an ignition circuit 32,33 respectively, supplying voltage to the spark plug 2,3 respectively, for igniting the fuel-air mixture fed into the respective combustion chamber.
• the negative end of the secondary winding 30,31, respectively, is in communication with the central electrode of the spark plug 2,3, respectively, this electrode thus obtaining a first negative ignition pulse for sparking over to the grounded electrode of the spark plug.
• the other, positive, end 34,35 respectively, of the secondary winding 30,31, respectively, is grounded via a line 36, which includes a measuring device 29.
• a measuring capacitor 40 in series with three lines 37,38,39 connected in parallel, each of the latter completing the grounding connection and also co- acting, in a manner explained below, .with a first detector unit 50 and a second detector unit 70 included in the measuring device 29.
• a voltage is generated which is used for charging the capacitor.
• This voltage is used in a voltage divider having two resistors 60,61 connected in series between the charging circuit 4 and ground.
• the resistance of the resistors 60,61 is chosen in such a manner that a predetermined constant voltage in the interval 70-400 volts is obtained at a point of connection 62 between the resistors.
• the point of connection 62 is via a line 14 and a connected diode 15, connected to the line 36 for voltage supply of the measuring capacitor 40.
• the point of connection 62 is also connected to ground via a transistor 63, with the base gate of the transistor being connected to the timing unit 6.
• the line 37 includes a Schottky diode 27 with its cathode connected to the capacitor 40 and its anode to ground.
• the line 38 includes a diode 45 with its cathode connected to a voltage stabiliser 46 functioning as a low voltage source and connected to ground by line 44. Said voltage stabiliser is also via a line 47 connected to the low voltage source 5, which also serves the charging circuit 4.
• a line 49 from the voltage stabiliser is connected between the resistors 41,42, and between the resistors 42,43 there is a voltage transfer via line 51 to the first detector unit 50.
• the line 51 transfers a reference voltage to the first detector unit 50, while a line 52 takes the voltage between the capacitor 40 and resistor 41 as an actual value to the first detector unit 50 and the second detector unit 70.
• a comparison takes place between the reference value on the line 51 and the actual value on the line 52, the comparison takes place in a comparator included (not shown) in the first detector unit.
• a signal on a line 53 from a measurement window unit 17 is also fed to the first detector unit 50.
• the measurement window unit obtains on a line 18 from the timing unit 6 an input signal relating to the time for triggering the ignition pulse, and on a line 19 an input signal relating to the prevailing crankshaft angular position.
• the output signal of the unit 17 on line 53 represents those ranges of the crankshaft angle, the so-called measurement windows, over which the first detector unit 50 shall operate for deciding whether ionising current flows in the ignition circuits 32,33 or not.
• the first detector unit 50 thus sends on lines 54,55 output signals representing either "detected” or “undetected” ionising current during different measurement windows, thus indicating on line 54 for example preignition, and on line 55 combustion knock, which combustion knock occurs during the later phase of the ionising current, i.e. the so-called post-ionisation phase.
• the second detector unit 70 coupled in parallel with the first detector unit 50 to the line 52, at which line 52 the current actual value representative of a ion current parameter is present, in this case a reduced voltage potential, where the voltage reduction is proportional to the increase of the ion current.
• the second detector unit 70 is the ion current signal processed enabling correction of the ignition timing in order to maintain optimum performance.
• An integrator is used in the first part 71 of the second detector unit, which integrator perform an integration of the actual value when a signal at line 80 from the measurement window unit 17 indicates that the second detector unit should start the integration , i.e. that the proper crankshaft range is present.
• the mass centre of the integral is thereafter calculated, which in a first embodiment could correspond to the crankshaft angle where parts of the integrated value on both sides of the mass centre have equivalent values.
• the circuit 70 receiving an input signal at line 87.
• the mass centre in the circuit 70 is a signal corresponding to the current position of the mass centre emitted at line 81 to a comparator 72.
• a comparison is made in the comparator of the current position of the mass centre and a target value, which target value is obtained at line 82 from a circuit 74 containing a memory with a map having prestored optimal target values for the crankshaft position of the mass centre dependent of different engine parameters, which preferably are empirically determined target values for the present type of engine.
• the target value changes dependent of at least the present engine speed and engine load, which parameters are detected by the circuit 74 at input terminals 85,86.
• the comparator transmit a signal at line 83, which signal is proportional to the detected difference between the current position of the mass centre and the target value for the type of engine used, which target value is obtained from the circuit 74.
• the amount of correction of the ignition timing which should be initiated dependent of the signal at line 83 is thereafter determined in circuit 73.
• the circuit could include "intelligent" means for correction, where for example a mean value determination of the difference between the current value and the target value is established over a predetermined number of cycles, whereby a gradual and smoother regulation is obtained.
• the circuit 73 give a ignition correcting signal to the timing unit 6 at line 84, dependent of existing difference between the current value and the target value.
• the ignition map could either be updated by the ignition correcting signal, which is preferable if the system should adapt to gradual changes in the engine and its auxiliary systems, or alternatively that the ignition correcting signal is temporarily stored until engine shut-down and a new start of the engine should be initiated, possibly at new conditions such as change of fuel or new/adjusted spark plugs, as an adaptable ignition correcting value subjected to change which affects the timing of following ignitions as read from the basic ignition map.
• figure 2 is shown the geometry of the combustion engine, which geometry is of use in an alternative embodiment in order to optimise the torque transmitted to the crankshaft dependent of the mechanics.
• this alternative embodiment is not a function of the mass centre target value used, which target value is stored in an empirically determined map in the circuit 74 shown in figure 1.
• FIG 2 is illustrated schematically a combustion engine having a piston arranged in the combustion chamber with attached piston rod (L), crankshaft angle ( ⁇ ) and crank length (R).
• the pressure P prevailing in the combustion chamber have effect upon the upper top surface A of the piston, which leads to;
• M( ⁇ ) P-R»A- ( — • (sin( ⁇ )-cos( ⁇ ) + sin( ⁇ ) ⁇ l - ( - sin( ⁇ )) 2 ) / ⁇ l - ( . sin( ⁇ ))
• the ionisation current is measured as mentioned previously by application of a constant bias voltage between 70-400 volts over a measuring gap arranged in the combustion chamber, preferably the spark plug gap.
• a constant bias voltage between 70-400 volts over a measuring gap arranged in the combustion chamber, preferably the spark plug gap.
• a varying conductivity is obtained conducting a current across the measuring gap. This current is called the ionisation current. From figure 4 one could see that from 0 degrees (crankangle degrees), i.e. when the piston is occupying the top dead centre position, and onwards there is a very good correspondence with the pressure curve P.
• the spark is triggered and a flame is developed in the spark plug gap causing a very high degree of ionisation shortly thereafter at -10 degrees of crankshaft position.
• the ionisation current have, up to 0 degrees of crankshaft position, the pressure superposed upon the flame-ionisation, i.e. the actual spark, and the flame in the spark plug gap ionises the fuel- air mixture and increases the conductivity in the measuring gap and hence also increases the ionisation current.
• the starting point from where the ionisation current start to correspond to the pressure could be obtained by observing when the first order derivative of the ionisation current change its sign.
• a corrected ionisation current calculated numerically, dependent of the design of the engine, i.e. compression ratio and crankshaft angle ⁇ , and approximation to the amplitude of the ionisation current at the starting point.
• the ionisation current curve be approximated up and until the upper dead position, by interpolating backwards in time the ion current signal from a point shortly after the upper dead position to the ignition timing point, where the ionisation current could be considered having a zero value.
• the contribution from the numerically calculated or the approximated ionisation current before the upper dead position is of less importance due to that this contribution, after filtering out the disturbances, have an essentially lower level of amplitude compared with the amplitude of the ionisation current after the upper dead position, whereby the numerically calculated or the approximated ionisation current before the upper dead position give an acceptable approximatioa
• M( ⁇ ) P R A- ( -• (sin( ⁇ )-cos( ⁇ ) + sin( ⁇ )- ⁇ l - (r - • sin( ⁇ )) 2 ) / Jl - (- ⁇ sin( ⁇ )) 2
• crankshaft angle ⁇ i - ⁇ 2 i.e. the present measuring window
• the present measuring window ⁇ i - ⁇ 2 could in reality correspond to a range of crankshaft positions from 0° - ⁇ 2 , where ⁇ 2 is a crankshaft position between 30-90° degrees of crankshaft position after the upper dead position, with a previously described numerical calculation or approximation of the ionisation current in the range of crankshaft positions between ⁇ i - 0°, where ⁇ i is a crankshaft position between 90- 40 degrees before the upper dead position. Control of the ignition timing should be performed in such a way that the value of this integral is maximised;
• ⁇ i leading to that optimal amount of torque could be obtained from the engine.
• Some restrictive conditions could naturally be implemented in order to reduce the load on the engine, which increase the length of life, and reduce combustion noise. These restrictive conditions could set limits for the ignition advance. I.e. the maximum and minimum allowable ignition advance, which restrictive conditions could be dependent of engine parameters, for example dependent of engine speed, load and temperature.
• the circuit 90 is in the same manner as shown in figure 1 connected to the line 52 where the present actual value of the ionisation current is represented, here in form of a reduced bias voltage, where the reduction is proportional to the increase of the ionisation current.
• detector unit 70a is the ionisation current affecting the correction of the ignition timing in
• ⁇ , ⁇ have an increasing tendency, i.e. that the actual value of the integral is higher than the values from preceding ignition events.
• the integral ⁇ Jr M j ⁇ d ⁇ calculated, when a signal appearing at line 80 from the measuring window unit 17 ⁇ , indicates that the detector unit 70a should start integration, i.e. that the interesting crankshaft range is present.
• the circuit 90 also obtains information regarding the present crankshaft position at line 87, for the execution of this calculation.
• the value is stored in a memory 91 , where a dedicated memory address contains the most recent integrated value and other memory addresses contains values from a number n of preceding ignition events, which could be equivalent to 5-30 of the recent preceding ignition events.
• a dedicated memory address contains the most recent integrated value and other memory addresses contains values from a number n of preceding ignition events, which could be equivalent to 5-30 of the recent preceding ignition events.
• each value of the memory addresses is shifted on step of time order, whereby the oldest value disappear.
• the integrator 90 have calculated a new value and subsequently stored this value in the memory 91, is a signal generated at line 95 to the comparator 92, which comparator then compares the most recent calculated value with the values stored in the memory 91 from preceding ignition events.
• the values from preceding ignition events could in an alternative embodiment, instead of being stored in individual memory addresses, form a mean value being stored in one individual memory address. If the integrated value have increasing tendency, then a signal is emitted to the ignition timing adjuster 93 indicating that the ignition timing correction ⁇ IgnP performed should be maintained in order of direction (increasing or decreasing ignition advance) and possibly also in order of step size. If the integrated value instead have decreasing tendency, then a signal is emitted to the ignition timing adjuster 93 indicating that the ignition timing correction ⁇ IgnP performed should be changed in order of direction, i.e. if the ignition timing correction performed previously was performed in the advance direction, meaning increasing ignition advance, then the ignition timing correction is changed instead to decreasing ignition advance
• the ignition timing correction ⁇ IgnP performed is preferably initiated in incremental steps in the order of some tens of crankshaft degrees or parts thereof. Optimising the ignition timing to a crankshaft position with maximum obtainable torque, is then performed relatively slowly and will not be affected to any major extent if some occasional non-uniform combustion's occur. If for example the ignition timing correction is initiated in steps of 0.01 degrees of crankshaft angle, then more than a hundred combustion's is needed for obtaining a total correction of the ignition timing of 1 degree of crankshaft angle, on condition that the integral is continuously increasing during these combustion's and as a consequence of the ignition timing correction initiated.
• a capacitive type of ignition system is used in the embodiment shown, demonstrating how the ionisation current could be detected.
• the inventive method is however not limited to application in capacitive type of ignition systems, and could nevertheless be applied in inductive type of ignition systems, where the entire step-up voltage is obtained in one step from 12 volt up to 30-40.000 volt, with switches of the lGBT-type(lnsulated Gate Bipolar Transistor) managing the current regulation, which switches could withstand the high currents developed in inductive type of ignition systems having the corresponding fast rise time of the ignition voltage.
• Fast rise time of the ignition voltage is one prerequisite for a non-configurable spark, i.e. a spark having a constant spark energy, not interfering with the ionisation current after the upper dead position also at high speeds too.
• a configurable spark be used, which spark during lower revs will be given longer burn duration, possibly by repeated triggering of sparks.
• the circuits shown in figure 1 and 3 have for the sake of clarity been represented as separated modules, but could also be implemented as analogue or digital circuits specially designed for the respective function needed.
• the integration circuit could for example be made of discrete components where the integration is realised in a condenser-based circuit, where the successively stored energy corresponds to the accumulated value from the integration.
• the integration and storage of values is made continuously by the computer, possibly controlled by interrupt-routines initiated at the moment of activation of the measuring windows.
• crankshaft angle as a base for integration and correction.
• time be used as a base, where for example the ignition timing or other synchronising pulses from the crankshaft sensor could be used as references for initiating the start of integration or correction.
• the time constitute a value representative for a crankshaft angle, in the same manner as will be given from an actually detected crankshaft angle.

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

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• 1994
  • 1994-08-11 SE SE9402686A patent/SE503171C2/sv unknown
• 1995
  • 1995-08-08 WO PCT/SE1995/000912 patent/WO1996005427A1/en active Application Filing
  • 1995-08-08 US US08/628,606 patent/US5676113A/en not_active Expired - Lifetime
  • 1995-08-08 DE DE19581041T patent/DE19581041C2/de not_active Expired - Fee Related

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