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
  • 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
  • F02P15/10—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 continuous electric sparks
• • 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
  • F02P9/00—Electric spark ignition control, not otherwise provided for
  • F02P9/002—Control of spark intensity, intensifying, lengthening, suppression

Definitions

• This invention pertains to an electronic ignition system and more particularly to an electronic ignition system which provides plurality of individual ignition sparks per each compression cycle of an internal combustion engine.
• the internal combustion engine is an inherently inefficient device, characterized by less than desirable fuel efficiency and problematic exhaust emissions.
• the primary source is the inefficient combustion of the air fuel mixture within the cylinder of the internal combus- tion engine. It is known that the fuel air mixture in the combustion chamber does not exist in a homogeneous state and thus the mixture's ignition, via an external ignition source, results in uneven and incomplete combustion of the fuel. Incomplete combustion implies a less than stoichiometric conversion of the fuel into energy and increased levels of unburned hydrocarbons in the side-reaction by-products in the exhaust emissions.
• a first approach focuses on the fuel and fuel error mixture and, more particularly, the distribution of the fuel/air mixture within the combustion chamber. Such modifications are the subject of carburetion and fuel injection technology.
• a second approach focuses on the ignition means utilized to initiate combustion of the fuel/air mixture.
• Conventional ignition systems both electronic and mechanical, provide for a single high energy spark per cylinder per compression stroke. Improvements in efficiency are achieved by adjusting parameters such as timing of the spark in relation to the compression stroke, the energy of the spark, duration of the spark, etc.
• OMPI enhancing efficiency are subject to certain ' limitations.
• TDC top dead center
• This problem is avoided in conventional ignition systems by lowering the compression ratio of the cylinder by firing the ignition spark below TDC, i.e. , before TDC.
• combusion temperatures in the cylinder do not exceed the 982°C level.
• Improved efficiency is also restricted by the physical limitations of the spark plug electrodes and more significantly, by the stratifica- tions of the fuel/air mixture within the cylinder chamber.
• This stratification effect occurs when the fuel/air mixture forms layers of varying temperature due to the various temperature regions present in the surrounding cylinder and piston.
• the effect of stratification on performance is most clearly evident when the engine is cold and the temperature variations are the greatest. Although the consequences of the stratification effect become less noticeable as the engine reaches normal operating temperatures, the stratification effect is still present and contributes to reduced fuel efficiency and increased exhaust emissions.
• a second system set forth in U.S. Patent 3,554,178, Boyer et al., provides a capacitor discharge ignition system which produces two sparks per cylinder per compression stroke in response to each half cycle of alternating current ignition signals.
• This system merely provides for a switching means by which two capacitors charge and discharge during each one half cycle of the ignition signal cycle.
• the timing of the ignition signals is fixed by the circuitry and does not adjust with changes in the revolutions per minute (RPM) of the engine.
• Other prior art ignition systems provide for multiple spark ignition wherein the number of sparks per cylinder compression stroke varyies directly in number in response to changes in the engine RPM. In these systems the relative relationship between the discrete spark outputs is fixed and the only adjustment is in the number of sparks per compression cycle.
• the prior art systems provide for a second and subsequent ignition sparks for reignition of the residual uncombusted air/fuel mixture, they all lack the ability to adjust the timing relationship between the individual spark signals in response to the rapid changes and fluctuations in the engine operating conditions or RPM.
• t is another object of this inventio " to provide a multiple spark electronic ignition system which is capable of producing a plurality of ignition sparks and electronically maintaining their relative relationship to each other as a function of the engine RPM.
• control means within the electronic ignition system which is designed to provide a timed sequence of ignition sparks, preferably
• OMH 3 to 20 sparks, per compression cycle is also capable of rapidly regulating and adjusting proportion ⁇ ally the timing of each sequence of sparks in response to the dynamic fluctuations in engine RPM.
• the number of individual ignitions, for each sequence is Q advantageously selected in accordance with one or more operating characteristics of the particular internal combustion engine. Once selected, however, the number of ignition sparks per compression cycle is fixed and the number of sparks per sequence cannot be changed 5 without replacing the control circuit.
• the timing control circuit operates under the same principle regardless of the number of ignition sparks selected and can regulate the time interval between each individual spark in the timed sequence as detected by changes in Q the engine RPM.
• the relative time intervals between each individual ignition signals are separately adjustable. These time intervals 5 can be altered either by manual adjustment of individual potentiometers that determine the relative reference voltage level, or by automatic electronic adjustments of the voltage levels applied to the negative input terminals of the plurality of comparator delays in Q response to engine operating conditions, i.e. , ambient temperature, ambient humidity, engine temperature, exhaust emission composition, etc.
• the automatic adjustments can be made by an electronic monitoring means which is programmed to alter the relative, not 5 just proportional, timing relationship of the sequence of pulse signals in response to input from sensors of the engine operating conditions.
• the ignition system of the present invention includes, but is not limited to the following features.
• a source of trigger pulse ignition signals produced in timed relation with the RPM of the engine which can either be a conventional cam/contact points distributor or the so called “electronic ignition” distributors which utilize magnetic induction transducers to provide trigger pulse ignition signals.
• Either trigger pulse ignition means is acceptable in the present invention.
• the present system can best be understood by following a single trigger pulse signal through the circuitry of the present invention. Once the initial trigger pulse is produced, it is feed to a non-inverting voltage comparator and converted into a wave signal. The wave signal is then transmitted to a discrete transistor which is used to isolate the rest of the components of the ignition system and prevent loading of the non-inverting voltage comparator. The wave signal is then fed to three independent components of the ignition system.
• the wave signal is fed to a multiple stage OR gate where the wave signal is converted into a voltage pulse.
• the voltage pulse is then used to trigger a onostable multivibrator which in turn enables or disables a high voltage/high current switching transistor thus delivering a high energy spark through the ignition coil.
• the second component of the system fed by the initial wave signal is a digital to analog generator.
• This digital to analog generator is triggered by the wave signal and produces an analog voltage proportional to the frequency of the input wave signal.
• the frequency of the input wave signal is a function of the RPM of the engine.
• the analog voltage is then fed to an inverting amplifier which responds to increasing input voltage with decreasing output voltage.
• OMPI Therefore, as the frequency of the input ' wave signal increases, in response to increasing engine RPM, the voltage taken from the inverter amplifier decreases.
• This inverting relationship and the subsequent use thereof provides the electronic control that regulates the time intervals between sparks and in response to changes in the engine RPM.
• the inverted voltage is then fed through two or more variable voltage dividers and to the negative input terminals of two or more input
• the negative input terminals of the comparators supply the reference voltage which must be exceeded by the positive input terminal voltage to initiate an output voltage.
• the variable voltage divider is positioned between the inverted voltage and ,5 the negative input terminals of the voltage comparators and are independently adjustable so that the reference voltage for each comparator can be set separately, either manually or automatically by a monitoring means.
• the initial wave signal is a sweep voltage ramp generator which converts the wave signal into a sweep voltage.
• a ramp voltage is an example of a sweep voltage.
• the sweep voltage is fed to the positive input terminals of the previously mentioned voltage
• the sweep voltage ramp is thus the triggering source for the voltage comparators and as the reference voltage level of each comparator is reached by the sweep voltage the comparators are sequencially triggered.
• the triggered output of each comparator is
• the present invention provides the electronic control means for producing a plurality of timed ignition signals from each of the trigger pulses.
• a timed sequence is produced by adjusting the real time (microseconds) between each of the ignition signals in said sequence; the adjustments are made in response to fluctuations in the engine RPM.
• the compression cycle time frame is decreased (increased) and therefore the time interval between the first, second and subsequent ignition sparks must be decreased (increased) in order to achieve completion of the timed sequence of sparks and maximum combustion of the air/- fuel mixture.
• the present invention achieves this result by providing an ignition system which generates second and subsequent ignition sparks from the sequential firing of a plurality of comparator delays which are characterized by having individually adjustable reference voltages that are inversely proportional to the engine RPM and positive input voltages in the form of a sweep voltage that is proportional to the engine RPM.
• Fig. 1 is a simplified block diagram of the multi-spark ignition system of the present invention and shows the various operational components of a triple spark ignition system;
• Fig. 2 is a schematic diagram of one of the preferred emobodiments of the present invention and provides for a triple spark ignition system.
• Fig. 3 (a-k) is a series of voltage verses time plots at different junctions within the multiple spark electronic ignition system.
• a multiple spark ignition system 20 including, a pulse means 3 for producing a plurality of trigger pulse signals; a control means 21, responsive to said trigger pulses, for generating a plurality of timed ignition signals for each of said trigger pulses and for controlling the frequency of said plurality of timed ignition signals as a function of engine RPM; an amplifying means 15 for transforming said sequence of timed ignition signals into a timed series of high energy ignition sparks. Pulse means 3 and control means
• Fig. 1 shows a trigger pulse source 2 and power supply 4, which may be the usual automobile battery.
• Input comparator 6 converts the trigger pulse into square waves and feeds them to isolator amplifier 8, the output of which is divided and fed to OR gate 10, digital to analog generator 12, and ramp generator 14.
• OR gate 10 converts the square wave from isolator amplifier 8 into an ignition pulse which is fed to amplifier 16 which converts each wave form from OR gate 10 into an output pulse.
• the output pulse is fed to monostable multivibrator 18 which is normally in the off state but is triggered into a conductive state by the pulse signal from amplifier 16.
• the conduction at monostable multivibrator 18 cuts off the normal current flow in output switching amplifier 20 and the primary ignition coil current rapidly decreases to 0 volts. As the current through output switching amplifier 20 decreases, a high voltage high current spark is generated in the secondary coil 22 and upon discharge provides a high energy ignition spark.
• the divided square wave of isolator amplifier 8 is also fed to digital to analog generator 12 which converts the digital square wave form into an analog voltage signal.
• the analog voltage is then inverted by inverter amplifier 24.
• the inverted analog voltage is fed to the negative or reference terminals of voltage delay 26 and 28.
• the third path for the square wave of isolator amplifier 8 is to ramp generator 14 which, converts the input square wave into a positive logarithmic ramp voltage.
• the ramp voltage is then ted to the positive or triggering terminals comparator delays 26 and 28.
• the reference voltage of comparator delays 26 and 28 can be independently adjusted even though it comes from the same source, inverter amplifier 24.
• comparator delay 26 is adjusted to provide a lower reference voltage than comparator delay 28; therefore comparator delay 26 is the first to be triggered by the raising ramp voltage from ramp generator 14.
• the output from comparator delay 26 is fed to OR gate 10 and through the amplification and switching means provided by amplifier 16, monostable multivibrator 18 and output switching amplifier 20 to produce the second high energy ignition spark.
• the ramp voltage from ramp generator 14 reaches the somewhat higher reference voltage of comparator delay 28 changes state, feeds its output signal to OR gate 10 and on to produce the third high energy -ignition spark.
• Fig. 1 provides for a triple spark ignition sequence, however, additional comparator delays can be incorporated into the circuit to produce any number of ignition sparks in sequence.
• Fig. 2 is a complete schematic diagram of a multi-spark ignition system which provides a timed sequence of three ignition sparks per cylinder compression cycle.
• OMPI I WIPO The system illustrated by Fig. 2 is comprised of integrated circuits 2 and discrete components.
• the trigger pulse 2 generated by either distributor cam/contact point or a magnetic induction transducer is sensed by comparator 4 at the positive (+) input terminal 6 through resistor 8.
• the negative (-) input terminal 10 of comparator 4 is ground referenced so that as the trigger pulse 2 voltage decreases from a negative potential, passing through zero voltage, then increases to its positive potential (See Fig. 3b) , comparator 4 responds by rapidly changing its output state as the input voltage positive terminal 6 exceeds the reference voltage at negative terminal 10.
• Resistors 8, 12, and 14 are fixed, as dictated by the operating requirements of comparator 4.
• Resistor 16 is a variable voltage divider provided for the purpose of fine tuning of distributor position relative to its advance/retard requirements.
• the output wave form of comparator 4 is sensed at the base of transistor 18 through resistor 20, a current limiting resistor. Upon sensing this positive voltage, transistor 18 is driven into conduction and a replica of the input wave form is reproduced between the emitter of transistor 18 and resistor 22 (See, Fig. 3b) .
• the function of transistor 18 is to provide isolation between comparator 4, capacitor 24, capacitor 26, and resistor 28. From the emitter of transistor 18 the wave form is fed to capacitor 24, capacitor 26, and resistor 28. Upon passing through current limiting resistor 28, the wave form is sensed at the positive (+) terminal 30 of ramp generator 32.
• a reference voltage is produced from between voltage dividers, resistors 34 and 36.
• Resistor 38 is fixed as dictated by the operating requirements of ramp generator 32.
• the output of ramp generator 32 rapidly changes state. For example, a change from a zero voltage level to ramp generator 32 supply voltage level, i.e. , 11.6 volts.
• Capacitor 40 starts an exponential charge through 42, producing a positive logarithmic voltage ramp (See Fig. 3d) which in turn is connected to resistors 44 and 46.
• the wave form produced at the emitter of transistor 18 is fed to capacitor 24, resistor 48, then to the input terminal 49 of digital to analog generator 50.
• Resistors 52, 54, 56, 58, capacitors 60, 62, 64, and diode 66 provide the necessary biasing as dictated by the operating requirement of digital to analog generator 50.
• Resistor 56 is adjusted for different voltage output, as determined by the number of cylinders of the internal combustion engine. For example, a 4 cylinder engine would require one value, while a 6 cylinder engine another, and an 8 cylinder engine yet another.
• the wave form to the input terminal of digital to analog generator 50 produces a voltage at its output 68 that is directly proportional to the frequency of the input wave forms.
• a 6 -cylinder engine has a idling RPM of 600.
• the input wave forms frequency at this RPM would be approximately 30 pulses per second.
• the output at this frequency would be approximately 30 pulses per second.
• the output at this frequency would be approximately +.25 volts.
• the output voltage would increase to approximately +1.5 volts.
• the output voltage would be approximately +3. volts.
• Digital to analog generator 50 works somewhat like a pump; the greater the input pulse frequency, the higher the output voltage.
• the resulting output voltage of digital to analog generator 50 is fed to the inverting transistor 70 and the biasing network resistor 72, resistor 74, resistor
• Resistors 78 and 80 form a voltage divider that sets the level of transistor 70 output voltage swing.
• the inverted output voltage produced from between the collector of transistor 70 and resistor 80 is fed to two separate variable voltage dividers resistor 82 and resistor 84, which function as potentiometers, to 86 and then to ground. Varying these potentiometers reduces or increases the level of voltage produced by digital to analog generator 50 and inverted by transistor 70. This voltage is then fed to the negative (-) terminals 88 and
• comparator delay 90 and comparator delay 92 is thereby used as a variable reference voltage.
• the positive logarithmic ramp voltage produced by ramp generator 32, resistor 42, and capacitor 40 is fed to the positive (+) terminals 94 and 96 of comparator delays 90 and 92 through current limiting resistors 44 and 46.
• Resistors 98, 100, 102, and 104 provide the necessary biasing as dictated by the operating requirements of comparator delays 90 and 92.
• Potentiometers, resistors 82 and 84 are adjusted to set specific reference levels at the negative (-) input terminals 88 and 89 of comparator delay 90 and comparator delay 92, so that as the logarithmic ramp voltage exceeds these reference levels, comparator delay
• comparator delay 90 and comparator delay 92 will change states in sequence. Consequently, as the engine RPM increases or decreases, comparator delay 90 and comparator delay 92 will change states because the reference voltage levels shift up and down, but will always maintain a fixed relationship to each other due to the potentiometer settings, resistors 82 and 84.
• the logarithmic ramp voltage then provides the trigger voltage and the constant time relationship between the first, second, and third pulse is preserved.
• the wave form from between the emitter of 18 and resistor 22 is fed to the integrating network, capacitor 26 and resistor 106, then to the diode 108, through the biasing network, resistors 110 and 112, to the base of the amplifier configuration of transistors 114 and 116.
• This wave form will initiate the first of the three sparks. (See, Fig. 3g) .
• the output wave forms from comparator delay 90 and comparator delay 92 are fed through the integrating network, capacitor 118, and resistor 120, capacitor 122 and resistor 124, to the diodes 126 and 128, through the biasing network, resistors 110 and 112, to the base of the amplifier configuration of transistors 114 and 116. See, Figs. 3h and 3i) .
• the OR gate network of diode 108, 126, 128, and resistors 110 and 112 provide three paths for the first, second, and third spark initiating components.
• the output pulses are then taken from between the emitter of transistor 116 and resistor 130, through coupling capacitor 132 to the base of transistor 134 biased by resistors 136 and 138.
• the circuit transistors 134, 140, resistors 136, 138, 142, 144, 146, 147, capacitor 148 and diode 150 form a monostable multivibrator in which transistor 134 is normally off and transistor 140 is normally conducting the supplying current to the ignition coil through transistor 152.
• a positive pulse from between the emitter of transistor 116 and resistor 130 fed through coupling capacitor 132 to the base transistor 134 causes transistor 134 to conduct for a period of time determined by resistor 146 and capacitor 148.
• transistor 134 While transistor 134 conducts, transistor 140 and 152 are cut off and the ignition primary coil current rapidly decreases to zero volts. As the current decreases, a high voltage, high current spark is generated in the secondary.
• the voltage supplied to 134 is held constant by zener diode regulator 154 and resistors 156 and 158.
• An anti-ringing zener 160 is connected between the collector of transistor 152 and ground to prevent this transistor's VCE rating from being exceeded due to a high voltage ring out after each spark is generated.

Landscapes

• Engineering & Computer Science (AREA)
• Chemical & Material Sciences (AREA)
• Combustion & Propulsion (AREA)
• Mechanical Engineering (AREA)
• General Engineering & Computer Science (AREA)
• Ignition Installations For Internal Combustion Engines (AREA)
• Spark Plugs (AREA)

Priority Applications (1)

Applications Claiming Priority (2)

Publications (1)

Family

ID=24227414

Family Applications (1)

Country Status (6)

Cited By (1)

Families Citing this family (3)

Citations (4)

Family Cites Families (6)

• 1984
  • 1984-12-03 EP EP84114676A patent/EP0147678A3/en not_active Withdrawn
  • 1984-12-05 KR KR1019850700148A patent/KR850700151A/ko not_active Application Discontinuation
  • 1984-12-05 AU AU37420/85A patent/AU3742085A/en not_active Abandoned
  • 1984-12-05 JP JP59504437A patent/JPS61500623A/ja active Pending
  • 1984-12-05 WO PCT/US1984/001983 patent/WO1985002657A1/en unknown
  • 1984-12-05 ZA ZA849480A patent/ZA849480B/xx unknown

Patent Citations (4)

Also Published As

Similar Documents

Legal Events