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WO2013077011A1 - Overlapping discharge-type ignition device for internal combustion engine - Google Patents

Overlapping discharge-type ignition device for internal combustion engine Download PDF

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Publication number
WO2013077011A1
WO2013077011A1 PCT/JP2012/062880 JP2012062880W WO2013077011A1 WO 2013077011 A1 WO2013077011 A1 WO 2013077011A1 JP 2012062880 W JP2012062880 W JP 2012062880W WO 2013077011 A1 WO2013077011 A1 WO 2013077011A1
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WO
WIPO (PCT)
Prior art keywords
voltage
output
superimposed
discharge
control means
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Ceased
Application number
PCT/JP2012/062880
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French (fr)
Japanese (ja)
Inventor
島田　直樹
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Hitachi Astemo Hanshin Ltd
Original Assignee
Hitachi Automotive Systems Hanshin Ltd
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Filing date
Publication date
Priority claimed from JP2011257296A external-priority patent/JP6041084B2/en
Priority claimed from JP2012011702A external-priority patent/JP6041085B2/en
Application filed by Hitachi Automotive Systems Hanshin Ltd filed Critical Hitachi Automotive Systems Hanshin Ltd
Publication of WO2013077011A1 publication Critical patent/WO2013077011A1/en
Anticipated expiration legal-status Critical
Ceased legal-status Critical Current

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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
    • F02P3/00—Other installations
    • F02P3/02—Other installations having inductive energy storage, e.g. arrangements of induction coils
    • F02P3/04—Layout of circuits
    • F02P3/0407—Opening or closing the primary coil circuit with electronic switching means
    • F02P3/0435—Opening or closing the primary coil circuit with electronic switching means with semiconductor devices
    • F02P3/0442—Opening or closing the primary coil circuit with electronic switching means with semiconductor devices using digital techniques
    • 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
    • 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
    • F02P3/00—Other installations
    • F02P3/02—Other installations having inductive energy storage, e.g. arrangements of induction coils
    • F02P3/04—Layout of circuits
    • F02P3/05—Layout of circuits for control of the magnitude of the current in the ignition coil
    • F02P3/051—Opening or closing the primary coil circuit with semiconductor devices
    • F02P3/053—Opening or closing the primary coil circuit with semiconductor devices using digital techniques
    • 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
    • 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
    • F02P9/007—Control of spark intensity, intensifying, lengthening, suppression by supplementary electrical discharge in the pre-ionised electrode interspace of the sparking plug, e.g. plasma jet ignition
    • 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
    • F02D41/20—Output circuits, e.g. for controlling currents in command coils
    • F02D2041/2003—Output circuits, e.g. for controlling currents in command coils using means for creating a boost voltage, i.e. generation or use of a voltage higher than the battery voltage, e.g. to speed up injector opening
    • F02D2041/2013—Output circuits, e.g. for controlling currents in command coils using means for creating a boost voltage, i.e. generation or use of a voltage higher than the battery voltage, e.g. to speed up injector opening by using a boost voltage source
    • 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
    • F02D41/20—Output circuits, e.g. for controlling currents in command coils
    • F02D2041/202—Output circuits, e.g. for controlling currents in command coils characterised by the control of the circuit
    • F02D2041/2058—Output circuits, e.g. for controlling currents in command coils characterised by the control of the circuit using information of the actual current value

Definitions

  • the present invention relates to an improvement of an ignition device for an internal combustion engine mounted on a motor vehicle, particularly an ignition device for a multi-discharge internal combustion engine.
  • the high voltage output of the DC-DC converter is superimposed on the secondary output of the ignition coil to superimpose the high voltage output of the DC-DC converter. It is necessary to select high voltage components for the transformer and the charge / discharge capacitor, and it is difficult to reduce the size of the DC-DC converter. For this reason, the DC-DC converter cannot be installed around the ignition coil, and the overlapping discharge function unit including the DC-DC converter must be installed at a site away from the ignition coil. In order to lead out the high voltage output to the ignition coil 2, high withstand voltage wiring is required. Therefore, the conventional ignition device for a multi-discharge internal combustion engine has problems in terms of cost and storage space.
  • the overlap time and overlap current are determined by the capacity of the charge / discharge capacitor. It is difficult to arbitrarily change the current.
  • the conventional overlap discharge type internal combustion engine ignition device retains the design overlap time and overlap current, and as a result, excessive discharge energy is supplied and unnecessary power consumption continues or ignition occurs. There is also a problem that the consumption of the plug electrode is accelerated.
  • the present invention can reduce the size of the apparatus at low cost, can be installed in a small in-vehicle space, can be diverted to a structure capable of controlling discharge time and discharge energy suitable for an internal combustion engine, and can stably discharge. It is an object of the present invention to provide an ignition device for a multi-discharge internal combustion engine that can maintain a supply of a super-multiple current necessary and sufficient.
  • the invention according to claim 1 is configured to block the current of the primary coil of the ignition coil in response to the ignition signal, induce a high voltage in the secondary coil, and have the same polarity as the high voltage.
  • an ignition device for a multi-discharge internal combustion engine that superimposes a voltage, causes a spark discharge in a discharge gap of an ignition plug, and ignites an air-fuel mixture in a combustion chamber, at the timing of high voltage induction of a secondary coil based on the ignition signal
  • a superimposed voltage generating operation control means for outputting a superimposed voltage generating alternating current of a required voltage / required frequency, and a voltage doubler rectifier circuit operating within a cycle of the superimposed voltage generating alternating current supplied from the superimposed voltage generating operation control means.
  • a multi-stage voltage doubler rectifier that combines multiple stages and outputs a DC high voltage that is several times the peak value of the input peak value, and outputs the DC high voltage output from the multi-stage voltage doubler rectifier.
  • the invention according to claim 2 interrupts the current of the primary coil of the ignition coil in response to the ignition signal, induces a high voltage in the secondary coil, and superimposes a voltage having the same polarity as the high voltage
  • an ignition device for a multi-discharge internal combustion engine that generates a spark discharge in a discharge gap of a plug and ignites an air-fuel mixture in a combustion chamber
  • the superimposed voltage generation AC and the superimposed voltage generation operation control means capable of increasing / decreasing the output power based on an external instruction, and the superimposed voltage generation AC supplied from the superimposed voltage generation operation control means.
  • a multi-stage voltage doubler rectifier that combines multiple voltage rectifier circuits operating in a cycle and outputs a DC high voltage that is multiple times the number of input voltages; and from the multi-stage voltage doubler rectifier
  • the DC high voltage to be applied is superposed with the same polarity as the high voltage induced in the secondary coil of the ignition coil, applied to the ignition plug to cause overlap discharge, and superposed by the multistage voltage doubler rectifier
  • While detecting the overlap current value it compares the preset overlap current set value with the actually detected overlap current detection value, and if the overlap current detection value is lower than the overlap current set value, the output increase instruction signal Is provided to the superimposed voltage generation operation control means, and when the overlap current detection value is higher than the overlap current set value, feedback control means is provided for outputting an output reduction instruction signal to the overlap voltage generation operation control means, and the feedback Adjusting the power output from the superimposed voltage generation operation control means to the multi-stage voltage doubler rectification means based on an output increase instruction signal or output reduction instruction signal from the control
  • the superimposed voltage generation operation control means receives an output increase instruction signal or an output reduction instruction signal from the feedback control means. The output is increased / decreased by a predetermined amount each time the signal is received.
  • the feedback control means increases or decreases the output according to the difference between the superposed current detection value and the superposed current set value.
  • an output increase instruction signal or an output decrease instruction signal including the determined output increase / decrease amount is transmitted to the superimposed voltage generation operation control means, and the superimposed voltage generation operation control means increases the output from the feedback control means.
  • the output power is increased or decreased according to the instruction signal or the output reduction instruction signal.
  • the superimposed voltage generation operation control means generates the superimposed voltage to be generated.
  • the power output to the multi-stage voltage doubler rectifying means is adjusted by changing the peak value of the AC for use.
  • the invention according to claim 6 is the ignition device for an overlap discharge type internal combustion engine according to any one of claims 2 to 4, wherein the superimposed voltage generation operation control means is a rectangular wave AC ON.
  • the power output to the multistage voltage doubler rectifier is adjusted by PWM control that changes the / OFF duty ratio.
  • PWM control that changes the / OFF duty ratio.
  • in the ignition apparatus for a supercharging internal combustion engine according to the first aspect by changing the voltage value of the superimposed voltage generating AC output from the superimposed voltage generating operation control means.
  • the voltage output from the multi-stage voltage doubler rectifier can be adjusted.
  • the invention according to claim 8 is the overlap time control means capable of arbitrarily controlling the drive time of the overlap voltage generation operation control means in the ignition device for the overlap discharge type internal combustion engine according to claim 1 or claim 7.
  • the superposition time of the DC high voltage generated by the multi-stage voltage doubler rectifier can be arbitrarily changed.
  • the invention according to claim 9 is the ignition device for a multiple discharge type internal combustion engine according to claim 1 or 7, wherein the multistage voltage doubler rectifier is housed in the same case as the ignition coil. It is characterized by doing so.
  • the superimposed voltage generating operation control means for outputting the superimposed voltage generating alternating current of the required voltage / required frequency at the timing of the high voltage induction of the secondary coil based on the ignition signal, and the superimposing Multi-stage voltage doubler that combines multiple voltage rectifier circuits that operate within the period of the superimposed voltage generation AC supplied from the voltage generation operation control means, and outputs a DC high voltage that is the number of stages of the input peak value.
  • the withstand voltage of the diode and capacitor used in each voltage doubler rectifier circuit constituting the multistage voltage doubler rectifier is sufficient to be about twice that of the superimposed voltage generating AC output. Because it is not necessary that a large capacity such as charging and discharging capacitor of a conventional lap discharge type ignition device for an internal combustion engine, enables miniaturization of cost containment and components, it can be installed to reasonably narrow automotive space.
  • the superimposed voltage generating alternating current of the required voltage / required frequency is output and output based on an instruction from the outside.
  • Superimposed voltage generation operation control means that can increase or decrease the power to be combined with a double voltage rectifier circuit that operates within the cycle of the superimposed voltage generation AC supplied from the superimposed voltage generation operation control means in multiple stages, and the number of input voltage stages And a multi-stage voltage doubler rectifier that outputs a double DC high voltage, and the DC high voltage output from the multi-stage voltage doubler rectifier is the same as the high voltage induced in the secondary coil of the ignition coil.
  • Overlap with polarity and apply to the spark plug to cause overlap discharge detect the overlap current value superimposed by the multistage voltage doubler rectifier, and When the overlap current detection value is lower than the overlap current set value, an output increase instruction signal is output to the superimposed voltage generation operation control means, and the overlap current detection value is overlapped.
  • feedback control means for outputting an output reduction instruction signal to the superimposed voltage generation operation control means when higher than the current set value, based on the output increase instruction signal or the output reduction instruction signal from the feedback control means, Feedback to increase or decrease the DC high voltage output from the multi-stage voltage doubler rectifier by adjusting the power output from the superposed voltage generation operation control means to the multi-stage voltage doubler rectifier, thereby bringing the overlap current detection value closer to the overlap current set value Since the control is performed, the withstand voltages of the diodes and capacitors used in each voltage doubler rectifier circuit constituting the multistage voltage doubler rectifier are superimposed voltage.
  • the feedback control by the feedback control means can increase or decrease the DC high voltage that is actually superimposed, and maintain the supply of sufficient overlap current necessary for stable discharge.
  • the superimposed voltage generation operation control means increases or decreases the output by a predetermined specified amount every time an output increase instruction signal or an output reduction instruction signal is received from the feedback control means. Since it did in this way, a feedback control means can be comprised comparatively easily.
  • the feedback control means determines the output increase / decrease amount according to the difference between the overlap current detection value and the overlap current set value, and the output increase includes the determined output increase / decrease amount.
  • An instruction signal or an output reduction instruction signal is transmitted to the superimposed voltage generation operation control means, and the superimposed voltage generation operation control means outputs power to be output in response to the output increase instruction signal or the output reduction instruction signal from the feedback control means. Since it is increased or decreased, it is possible to quickly cope with a sudden change in the detected overlap current value.
  • the superimposed voltage generation operation control means adjusts the power output to the multistage voltage doubler rectifier means by changing the peak value of the generated superimposed voltage generating alternating current.
  • the superimposed voltage generation operation control means adjusts the power output to the multistage voltage doubler rectification means by PWM control that changes the ON / OFF duty ratio of the rectangular wave AC. Therefore, it is possible to cope with output reduction or mainstream direct increase using a rectangular wave alternating current with a predetermined peak value.
  • the voltage output from the multi-stage voltage doubler rectifier can be adjusted by changing the voltage value of the superimposed voltage generating AC output from the superimposed voltage generating operation control unit. Since it did in this way, the discharge current which can perform the discharge of the characteristic suitable for the state of air-fuel mixture can be sent.
  • the superposition time control means capable of arbitrarily controlling the drive time of the superposition voltage generation operation control means is provided, and the superposition time of the DC high voltage generated by the multistage voltage doubler rectification means. Since the discharge current can be arbitrarily changed, the discharge current can be continued for an overlap time that allows discharge having characteristics suitable for the state of the air-fuel mixture.
  • the overlap time and the overlap current can be arbitrarily changed, the optimum discharge time and the optimum discharge energy are supplied to the mixture state. In addition, it is possible to avoid problems such as wasteful power consumption due to excessive discharge energy being supplied and rapid consumption of the spark plug electrode.
  • the multistage voltage doubler rectifier since the multistage voltage doubler rectifier is housed in the same case as the ignition coil, a high voltage supply line from the multistage voltage doubler rectifier to the ignition coil. Can be accommodated in the case, and it is not necessary to route the DC high-voltage line, and it is not necessary to secure a high-breakdown-voltage wiring material and wiring space.
  • FIG. 1 is a schematic configuration diagram of an ignition device for a multi-discharge internal combustion engine shown as an embodiment of the present invention.
  • FIG. 2 is an operation waveform diagram at the time of ignition in the ignition device for the multiple discharge internal combustion engine of FIG.
  • FIG. 1 shows a schematic configuration of an embodiment in which an ignition device for a multiple discharge type internal combustion engine according to the present invention is applied to an engine ignition device for a vehicle.
  • An ignition coil 1 (for example, a primary coil 1a, a secondary coil 1b) is shown.
  • the iron core 1c and the switching element 1d) cause a spark discharge in the discharge gap g of the spark plug 2, and ignites the air-fuel mixture in the combustion chamber of the vehicle engine (not shown).
  • the switching element 1d of the ignition coil 1 is turned on by an ignition signal from the engine control unit (ECU), a current flows to the primary coil 1a to which the DC voltage VB is supplied from a vehicle battery (not shown).
  • ECU engine control unit
  • the switching element 1d is turned off at the falling edge of the ignition signal, the current of the primary coil 1a is cut off, and a spark discharge is caused in the gap g between the discharges of the spark plug 2 by the high voltage induced in the secondary coil 1b. . Therefore, in the ignition apparatus for a multi-discharge internal combustion engine according to this embodiment, in order to generate a voltage to be superimposed on the high voltage induced in the secondary coil 1b, the “high voltage of the secondary coil based on the ignition signal” is generated.
  • DC-AC booster circuit 3 serving as a superimposed voltage generation operation control means that outputs alternating current for generating a superimposed voltage having a required voltage / required frequency at the induction timing and that can increase or decrease the output power based on an external instruction.
  • the superposition voltage generation AC for example, AC200V
  • the multi-stage voltage doubler rectifier circuit 4 serving as a “multi-stage voltage doubler rectifier that outputs a DC high voltage” is supplied to the multi-stage voltage doubler rectifier circuit 4 and the DC high voltage (for example, DC1.2 V) is output, by superimposing the DC high voltage to the induced voltage of the secondary coil 1b, is to adjust the size and the discharge time of the discharge current that causes the ignition plug 2.
  • a high voltage diode 5 is provided between the secondary coil 1b and the ground point so that the secondary coil 1b side is an anode and the ground side is a cathode, and the DC high voltage output from the multistage voltage doubler rectifier circuit 4 is provided.
  • the high voltage induced in the secondary coil 1 b is superimposed with the same polarity.
  • the DC-AC booster circuit 3 starts operating at the timing when the switching element 1d of the ignition coil 1 is turned off by the ignition signal (for example, the detection timing of the pulse falling of the ignition signal), and after a predetermined overlap time has elapsed, although the operation may be stopped by, for example, “the overlap time control means that can arbitrarily control the drive time of the overlap voltage generation operation control means so that the overlap time according to the combustion characteristics of the internal combustion engine can be easily adjusted.
  • the superposition time control circuit 6 is provided, and the superposition time (time for outputting the superposition voltage generation AC from the DC-AC booster circuit 3) can be arbitrarily changed by setting the superposition time control circuit 6. I made it.
  • a current detection resistor 7 is provided at an appropriate discharge path of the spark plug 2 (for example, between the high voltage diode 5 and the grounding point) so that the actually flowing discharge current can be detected by the overlapping current detection / comparison circuit 8.
  • This overlap current detection / comparison circuit 8 can store the overlap current setting value based on the overlap current setting signal input from the outside, and “detects the overlap current value superimposed by the multi-stage voltage doubler rectifier. At the same time, the preset overlap current setting value is compared with the actually detected overlap current detection value. When the overlap current detection value is lower than the overlap current set value, the output increase instruction signal is generated.
  • the overlap current detection value When the overlap current detection value is higher than the overlap current set value, it functions as feedback control means for outputting an output reduction instruction signal to the superimposed voltage generation operation control means ”. That is, based on the output increase instruction signal or the output decrease instruction signal from the overlap current detection / comparison circuit 8, the power (the peak value of the superimposed voltage generation AC) output from the DC-AC booster circuit 3 to the multistage voltage doubler rectifier circuit 4.
  • the discharge current detected by the overlap current detection / comparison circuit 8 includes a spike-like discharge current based on a high voltage induced in the secondary coil 1b. For example, a predetermined time has elapsed from the detection timing of the discharge current. A current value detected later may be taken in as an overlap current detection value and used for comparison with the overlap current set value.
  • the overlap time control signal output from the overlap time control circuit 6 to the DC-AC booster circuit 3 is turned ON at the timing when the secondary voltage is induced in the secondary coil 1b (timing of the pulse fall of the ignition signal). (For example, the signal level is changed from L to H), and output of the superimposed voltage generation AC by the DC-AC booster circuit 3 is started.
  • the DC-AC booster circuit 3 continues to output the superimposed voltage generation AC until the overlap time control signal from the overlap time control circuit 6 is turned off (the signal level changes from H to L).
  • a high DC voltage is output from the voltage doubler rectifier circuit 4.
  • the DC-AC booster circuit 3 is exemplified by a DC voltage VB (for example, DC12V) of the on-vehicle battery that is output with an AC voltage of 200V.
  • a DC voltage VB for example, DC12V
  • the multistage voltage doubler rectifier circuit 4 that receives the superimposed voltage generating alternating current from the DC-AC booster circuit 3 configured as described above is a voltage doubler rectifier circuit that outputs a direct current voltage that is twice the peak value of the input alternating current.
  • a DC high voltage of 1.2 kV DC which is 6 times higher than the AC 200 V input, can be obtained.
  • the voltage doubler rectifier circuit used for the multistage voltage doubler rectifier circuit 4 may be a known one.
  • the capacitor C1 is charged by the diode D1
  • the capacitor C2 is charged by the diode D2.
  • the capacitor C3, the capacitor C4, the capacitor C5, and the capacitor C6 by the diode D3, the diode D4, the diode D5, and the diode D6, the capacitor C2, the capacitor C4, and the capacitor C6 connected in series are Since each is charged to approximately twice the input peak value, a direct current of 6 times the voltage (capacitor charging voltage ⁇ 2 ⁇ number of stages) can be obtained.
  • the withstand voltages of the diodes D1 to D6 and the capacitors C1 to C6 of each voltage doubler rectifier circuit are all for generating a superimposed voltage. Since there is no problem if it is twice or more the AC voltage value, there is no need for a large capacity like the charge / discharge capacitor of the conventional ignition device for a multi-discharge internal combustion engine, and it is possible to reduce the size and cost of parts.
  • the multistage voltage doubler rectifier circuit 4 is not limited to three stages, and may be two stages or four stages or more.
  • the DC high voltage of 1.2 kV obtained from the multistage voltage doubler rectifier circuit 4 as described above continues until the overlap time control signal of the overlap time control circuit 6 is turned off (the signal level changes from H to L). Is output.
  • the DC high voltage obtained from the multi-stage voltage doubler rectifier circuit 4 is superimposed on the high voltage induced in the secondary coil 1b, it must be superimposed with the same polarity as the high voltage induced in the secondary coil 1b. Therefore, the superimposed voltage on the discharge electrode becomes an inverted waveform of the output of the multistage voltage doubler rectifier circuit.
  • the DC high voltage output from the multistage voltage doubler rectifier circuit 4 is the same as the high voltage induced in the secondary coil 1b of the ignition coil 1.
  • the discharge waveform of the spark plug 2 is superimposed with the DC high voltage from the multi-stage voltage doubler rectifier circuit 4 even after a large current at the beginning of ignition flows, as shown in FIG.
  • the discharge of the spark plug 2 continues until the overlap time controlled by the overlap time control circuit 6 elapses, and the overlap current equal to the overlap current set value continues to flow.
  • the DC-AC booster circuit 3 that outputs the superimposed voltage generating alternating current
  • the multistage that receives the superimposed voltage generating alternating current and generates a direct high voltage. Since the voltage doubler rectifier circuit 4 is used, the voltage value of the superimposed voltage generation AC output from the DC-AC booster circuit 3 serving as the superimposed voltage generation operation control means is increased or decreased.
  • the voltage output from the multi-stage voltage doubler rectifier circuit 4 as the multi-stage voltage doubler rectifier can be adjusted to be higher or lower, so that a discharge current capable of discharging with characteristics suitable for the state of the air-fuel mixture can flow. it can.
  • the driving time of the DC-AC booster circuit 3 as the superimposed voltage generation operation control means can be arbitrarily controlled by the overlap time control circuit 6 as the overlap time control means, the direct current generated by the multi-stage voltage doubler rectifier circuit 4 can be controlled.
  • the stacking time of the high voltage can be lengthened, shortened, or arbitrarily changed, and the discharge current can be continued for a stacking time that allows discharge having characteristics suitable for the state of the air-fuel mixture.
  • the discharge energy adjustment function by the DC-AC booster circuit 3 and the overlap time adjustment function by the overlap time control circuit 6 are used together, the discharge energy superimposed on the overlap time can be arbitrarily changed.
  • the multistage voltage doubler rectifier circuit 4 can be configured with small components, it can be easily housed in the same case as the ignition coil 1.
  • the multistage voltage doubler rectifier circuit 4 and the high voltage diode 5 are housed in the same case as the ignition coil 1, the high voltage supply line from the multistage voltage doubler rectifier circuit 4 can be housed in the case, and the direct current There is no need to route a high voltage line, and it is not necessary to secure a wiring material or wiring space with a high breakdown voltage.
  • an AC 200 V superimposed voltage generating alternating current is supplied from the DC-AC booster circuit 3 to the multistage voltage doubler rectifier circuit 4 and output from the multistage voltage doubler rectifier circuit 4.
  • the overlap current detection / comparison circuit 8 As a result of the overlap current detection / comparison circuit comparing the overlap current detection value and the overlap current setting value, the absolute value of the overlap current detection value is larger than the absolute value of the overlap current setting value. If it is smaller, the overlap current detection / comparison circuit 8 outputs an output increase instruction signal to the DC-AC booster circuit 3, and the DC-AC booster circuit 3 that has received this signal outputs a predetermined specified amount (for example, 1 V).
  • the peak value of the superimposed voltage generating AC is increased, the output voltage of the multi-stage voltage doubler rectifier circuit 4 is increased (for example, increased by about 6 V, which is 6 times the added voltage), and the superimposed voltage on the discharge electrode is increased and superimposed. Increase current.
  • the overlap current detection / comparison circuit 8 detects and compares the increased overlap current, and if the overlap current detection value is still less than the overlap current set value, the overlap current detection / comparison circuit 8 outputs an output increase instruction signal. Output to the DC-AC booster circuit 3 to further slightly increase the peak value of the superimposed voltage generating AC. If the overlap current detection value and the overlap current setting value match, the overlap increase detection / comparison circuit 8 does not output an output increase instruction signal to the DC-AC booster circuit 3. Since the output peak value of the superimposed voltage generating AC is maintained as it is, the superimposed voltage from the multistage voltage doubler rectifier circuit 4 to the discharge electrode is also maintained as it is, and the overlap current that matches the overlap current set value is maintained.
  • the overlap current detection / comparison circuit compares the overlap current detection value with the overlap current setting value and the absolute value of the overlap current detection value is greater than the absolute value of the overlap current setting value
  • the overlap current detection / comparison The circuit 8 outputs an output reduction instruction signal to the DC-AC booster circuit 3, and the DC-AC booster circuit 3 that has received this signal outputs the peak value of the superimposed voltage generating AC by a predetermined amount (for example, 1 V).
  • the output voltage of the multistage voltage doubler rectifier circuit 4 is reduced (for example, reduced by about 6 V, which is six times the added voltage), and the superimposed voltage on the discharge electrode is lowered to reduce the superimposed current.
  • the overlap current detection / comparison circuit 8 detects and compares the reduced overlap current, and if the overlap current detection value still exceeds the overlap current set value, the overlap current detection / comparison circuit 8 instructs the output reduction.
  • the signal is output to the DC-AC booster circuit 3 to further reduce the peak value of the superimposed voltage generating AC. If the overlap current detection value matches the overlap current setting value, the overlap reduction detection / comparison circuit 8 does not output an output reduction instruction signal to the DC-AC booster circuit 3, and therefore the DC-AC booster circuit 3 Since the output peak value of the superimposed voltage generating AC is maintained as it is, the superimposed voltage from the multistage voltage doubler rectifier circuit 4 to the discharge electrode is also maintained as it is, and the overlap current that matches the overlap current set value is maintained.
  • the overlap current set value which is the reference for feedback control by the overlap current detection / comparison circuit 8
  • the overlap current set value can be arbitrarily set by inputting an overlap current setting signal from the outside. Since the optimum overlap current value can be set according to the characteristics of the engine to which the device is applied, the versatility of the device can be enhanced.
  • the feedback control realized by the superimposed current detection / comparison circuit 8 and the DC-AC booster circuit 3 is not limited to the above-described method, and a known existing method may be appropriately used. For example, a correspondence table or an arithmetic expression in which the difference between the overlap current set value and the overlap current detection value and the output increase / decrease value instructed to the DC-AC booster circuit 3 to fill this difference is associated with the overlap current detection / comparison.
  • a signal (an output increase instruction signal or an output decrease instruction signal) including an output increase / decrease amount determined from the correspondence table or the arithmetic expression is stored in the circuit 8 from the overlap current detection / comparison circuit 8 to the DC-AC booster circuit 3.
  • the DC-AC booster circuit 3 that receives this signal changes the peak value of the superimposed voltage generating AC based on the instruction information, and increases or decreases the charging voltage from the multistage voltage doubler rectifier circuit 4 to the discharge electrode at once.
  • the overlap current may be brought close to the set value quickly. Further, in the above-described embodiment of the ignition device for the multi-discharge internal combustion engine, the power supplied to the multistage voltage doubler rectifier circuit 4 by changing the peak value of the superimposed voltage generating AC supplied from the DC-AC booster circuit 3.
  • the charging voltage of each of the capacitors C1 to C6 of the multistage voltage doubler rectifier circuit 4 is increased or decreased to increase or decrease the superimposed voltage on the discharge electrode, but the method of increasing or decreasing the charging voltage to the discharge electrode is as follows: It is not limited to this.
  • PWM control means 3a (configured by a chopper circuit or an inverter circuit) in the DC-AC booster circuit 3 and changing the ON / OFF duty ratio of the rectangular wave as the superimposed voltage generating AC, a multi-stage The power supplied to the voltage doubler rectifier circuit 4 may be changed.
  • the PWM control means 3a When the ON duty time of the superimposed voltage generating alternating current (rectangular wave) is changed by the PWM control means 3a, although the peak value of the rectangular wave input to the multistage voltage doubler rectifier circuit 4 does not change, it depends on the ON / OFF duty ratio. Since the charging voltage of each of the capacitors C1 to C6 increases or decreases, the DC voltage obtained from the multistage voltage doubler rectifier circuit 4 can be adjusted.
  • the PWM control means 3a may not be included as one function of the DC-AC booster circuit 3, but may be provided as an independent chopper circuit or the like on the output side of the DC-AC booster circuit 3.
  • an increase / decrease instruction from the overlap current detection / comparison circuit 8 is supplied to the PWM control means 3a, and the PWM control means 3a generates a predetermined peak value generated by the DC-AC booster circuit 3 based on this instruction.
  • the PWM control means 3a By performing control to change the ON / OFF duty ratio with respect to the rectangular wave (for example, 200 V), the superimposed voltage generation AC is output from the PWM control unit 3a.

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Abstract

Provided is a discharge-type ignition device for an internal combustion engine with which a low cost and a reduced size can be achieved, and which can be installed in a narrow mounting space, and with which it is possible to maintain the supply of overlapping current necessary for a stable discharge. An ignition device for an internal combustion engine, with which a discharge breakdown is produced in the discharge gap (g) of an ignition plug (2) and a discharge current flows by means of an ignition coil (1) that is operated on the basis of an ignition signal, is equipped with an overlapping discharge function. The configuration is such that an overlap time control circuit (6) causes a DC-AC booster circuit (3) to operate, and alternating current for generating an overlapping voltage is supplied to a multistage voltage-doubling rectifier circuit (4), and the obtained direct-current high voltage is overlapped with the same polarity with the induction voltage of a secondary coil (1b). The charge voltage to a discharge electrode is detected by an overlapping current detection/comparison circuit (8), and compared with an overlapping current set value. If the detected value for the overlapping current is lower than the set value, the value for the wave height of the alternating current from the DC-AC booster circuit (3) for generating the overlapping voltage is raised, and if the detected value is higher than the set value, the value for the wave height of the alternating current from the DC-AC booster circuit (3) for generating the charge voltage is lowered, thereby bringing the detected value for the overlapping current close to the set value.

Description

重ね放電型内燃機関用点火装置Ignition device for overlap discharge type internal combustion engine

　本発明は、自動車両に搭載される内燃機関の点火装置、特に重ね放電型内燃機関用点火装置の改良に関する。 The present invention relates to an improvement of an ignition device for an internal combustion engine mounted on a motor vehicle, particularly an ignition device for a multi-discharge internal combustion engine.

　最近では車両搭載の内燃機関として、燃費改善の為にリーンバーンエンジンや高ＥＧＲエンジンが採用されているが、これらのエンジンは着火効率が余り良くないため、点火装置には高エネルギー型のものが必要になる。そこで、従来からも、古典的な電流遮断原理により発生する点火コイル二次側出力にＤＣ−ＤＣコンバータの高圧出力を重畳する重ね放電型内燃機関用点火装置が提案されている（例えば、特許文献１を参照）。
　このような従来の重ね放電型内燃機関用点火装置では、点火コイルの一次電流を遮断することにより点火コイルの二次側に発生する数ｋＶの高圧電圧により、点火プラグの放電間隙に放電破壊を起こし、点火コイルの二次側から放電電流を流し始めた後に、当該放電状態を維持し得る放電維持電圧値以上の直流電圧（普通、５００Ｖ程度以上）を別途に設けた昇圧回路によって保ちながら、当該昇圧回路からの出力電流を点火コイル放電電流に加算的に重畳する。事実、このような重ね放電型内燃機関用点火装置によると、点火プラグに比較的長い時間に亘り大きな放電エネルギーを得ることができるため、燃料への着火性が向上し、ひいては燃費も向上する。 Recently, lean burn engines and high EGR engines have been adopted as internal combustion engines mounted on vehicles to improve fuel efficiency, but these engines are not very efficient in ignition. I need it. In view of this, an ignition device for a multi-discharge internal combustion engine that superimposes the high-voltage output of the DC-DC converter on the secondary output of the ignition coil generated by the classic current interruption principle has been proposed (for example, patent document). 1).
In such a conventional igniter for a multi-discharge internal combustion engine, by interrupting the primary current of the ignition coil, a high voltage of several kV generated on the secondary side of the ignition coil causes discharge breakdown in the discharge gap of the spark plug. Waking up and starting to flow a discharge current from the secondary side of the ignition coil, while maintaining a DC voltage (usually, about 500 V or more) higher than the discharge sustaining voltage value capable of maintaining the discharge state by a separately provided booster circuit, The output current from the booster circuit is additionally superimposed on the ignition coil discharge current. In fact, according to such an ignition device for a multi-discharge internal combustion engine, a large discharge energy can be obtained in the spark plug for a relatively long time, so that the ignitability to the fuel is improved and the fuel consumption is also improved.

特開平８−６８３７２号公報JP-A-8-68372

　しかしながら、上記特許文献１に記載された重ね放電型内燃機関用点火装置においては、点火コイル二次側出力にＤＣ−ＤＣコンバータの高圧出力を重畳するため、ＤＣ−ＤＣコンバータの高圧部、特に昇圧トランスと充放電用コンデンサには高耐圧の部品を選定する必要があり、ＤＣ−ＤＣコンバータの小型化は困難である。このため、ＤＣ−ＤＣコンバータを点火コイル周辺に設置するわけにはいかず、ＤＣ−ＤＣコンバータを含む重ね放電機能部を点火コイルから離れた部位に設置せざるを得ないため、重ね放電機能部からの高圧出力を点火コイル２へ導出するために高耐圧の配線が必要になる。よって、従来の重ね放電型内燃機関用点火装置では、コストや収納スペースの面で問題が生じる。
　また、リーンバーンエンジンや高ＥＧＲ等では、混合気の状態によって、同じ高エネルギーであっても短放電が望ましいケースや長放電が望ましいケースもあるため、混合気の状態に適した特性の放電を行えるような重ね放電型内燃機関用点火装置への要求があるものの、従来の重ね放電型内燃機関用点火装置では、重ね時間や重ね電流は充放電用コンデンサの容量で決まるため、重ね時間や重ね電流を任意に変更することは困難である。
　しかも、従来の重ね放電型内燃機関用点火装置は、設計上の重ね時間や重ね電流が保持されるため、結果的に、必要以上の放電エネルギーが供給されて無駄な電力消費が続いたり、点火プラグ電極の消耗を早めてしまうといった問題もある。逆に、無駄な電力消費を抑えるためにギリギリの重ね電流を重畳する設計とした場合は、重ね電流が不足して適正な燃焼状態を維持できなくなったり、最悪の場合は失火するなど、燃焼に悪影響を及ぼすおそれがある。
　そこで、本発明は、低コストで装置の小型化が可能で、狭小な車載スペースへ設置できると共に、内燃機関に適した放電時間や放電エネルギーの制御が可能な構造に転用でき、安定した放電を行うのに必要十分な重ね電流の供給を維持できる重ね放電型内燃機関用点火装置の提供を目的とする。 However, in the ignition device for the overlap discharge type internal combustion engine described in Patent Document 1 above, the high voltage output of the DC-DC converter, particularly the booster, is superimposed on the secondary output of the ignition coil to superimpose the high voltage output of the DC-DC converter. It is necessary to select high voltage components for the transformer and the charge / discharge capacitor, and it is difficult to reduce the size of the DC-DC converter. For this reason, the DC-DC converter cannot be installed around the ignition coil, and the overlapping discharge function unit including the DC-DC converter must be installed at a site away from the ignition coil. In order to lead out the high voltage output to the ignition coil 2, high withstand voltage wiring is required. Therefore, the conventional ignition device for a multi-discharge internal combustion engine has problems in terms of cost and storage space.
In lean burn engines, high EGR, etc., there are cases where short discharge is desirable and long discharge is desirable even with the same high energy depending on the state of the air-fuel mixture. Although there is a need for an ignition device for a multi-discharge internal combustion engine that can be performed, in the conventional multi-discharge internal combustion engine ignition device, the overlap time and overlap current are determined by the capacity of the charge / discharge capacitor. It is difficult to arbitrarily change the current.
Moreover, the conventional overlap discharge type internal combustion engine ignition device retains the design overlap time and overlap current, and as a result, excessive discharge energy is supplied and unnecessary power consumption continues or ignition occurs. There is also a problem that the consumption of the plug electrode is accelerated. On the other hand, if it is designed to superimpose a superlative current in order to reduce wasteful power consumption, it will not be possible to maintain an appropriate combustion state due to insufficient supercurrent, or in the worst case a misfire will occur. There is a risk of adverse effects.
Therefore, the present invention can reduce the size of the apparatus at low cost, can be installed in a small in-vehicle space, can be diverted to a structure capable of controlling discharge time and discharge energy suitable for an internal combustion engine, and can stably discharge. It is an object of the present invention to provide an ignition device for a multi-discharge internal combustion engine that can maintain a supply of a super-multiple current necessary and sufficient.

　上記課題を解決するために、請求項１に係る発明は、点火信号に応じて点火コイルの一次コイルの電流を遮断し、二次コイルに高電圧を誘起させると共に、該高電圧と同極性の電圧を重畳し、点火プラグの放電間隙に火花放電を起こして、燃焼室内の混合気に点火する重ね放電型内燃機関用点火装置において、前記点火信号に基づく二次コイルの高電圧誘起のタイミングで、所要電圧・所要周波数の重畳電圧生成用交流を出力する重畳電圧生成動作制御手段と、前記重畳電圧生成動作制御手段から供給される重畳電圧生成用交流の周期内で作動する倍電圧整流回路を多段に組み合わせ、入力尖頭値の段数倍の直流高電圧を出力するようにした多段倍電圧整流手段と、を備え、前記多段倍電圧整流手段から出力される直流高電圧を、前記点火コイルの二次コイルに誘起する高電圧と同極性で重畳し、点火プラグに印加することにより重ね放電を行わせるようにしたことを特徴とする。
　また、請求項２に係る発明は、点火信号に応じて点火コイルの一次コイルの電流を遮断し、二次コイルに高電圧を誘起させると共に、該高電圧と同極性の電圧を重畳し、点火プラグの放電間隙に火花放電を起こして、燃焼室内の混合気に点火する重ね放電型内燃機関用点火装置において、前記点火信号に基づく二次コイルの高電圧誘起のタイミングで、所要電圧・所要周波数の重畳電圧生成用交流を出力すると共に、外部よりの指示に基づいて出力する電力を増減可能な重畳電圧生成動作制御手段と、前記重畳電圧生成動作制御手段から供給される重畳電圧生成用交流の周期内で作動する倍電圧整流回路を多段に組み合わせ、入力電圧の段数倍の直流高電圧を出力するようにした多段倍電圧整流手段と、を備え、前記多段倍電圧整流手段から出力される直流高電圧を、前記点火コイルの二次コイルに誘起する高電圧と同極性で重畳し、点火プラグに印加することにより重ね放電を行わせ、前記多段倍電圧整流手段により重畳された重ね電流値を検出すると共に、予め設定された重ね電流設定値と実際に検出された重ね電流検出値とを比較し、重ね電流検出値が重ね電流設定値よりも低い場合には出力増加指示信号を前記重畳電圧生成動作制御手段へ出力し、重ね電流検出値が重ね電流設定値よりも高い場合には出力低減指示信号を前記重畳電圧生成動作制御手段へ出力するフィードバック制御手段を設け、前記フィードバック制御手段からの出力増加指示信号または出力低減指示信号に基づいて、前記重畳電圧生成動作制御手段が多段倍電圧整流手段へ出力する電力を調整することで、多段倍電圧整流手段から出力される直流高電圧を増減させ、重ね電流検出値を重ね電流設定値へ近づけるフィードバック制御を行うようにしたことを特徴とする。
　また、請求項３に係る発明は、前記請求項２に記載の重ね放電型内燃機関用点火装置において、前記重畳電圧生成動作制御手段は、前記フィードバック制御手段から出力増加指示信号もしくは出力低減指示信号を受ける毎に、予め定めた規定量だけ出力を増減させるようにしたことを特徴とする。
　また、請求項４に係る発明は、前記請求項２に記載の重ね放電型内燃機関用点火装置において、前記フィードバック制御手段は、重ね電流検出値と重ね電流設定値との差に応じて出力増減量を決定すると共に、決定した出力増減量を含む出力増加指示信号もしくは出力低減指示信号を前記重畳電圧生成動作制御手段へ送信し、前記重畳電圧生成動作制御手段は、フィードバック制御手段からの出力増加指示信号もしくは出力低減指示信号に応じて、出力する電力を増減するようにしたことを特徴とする。
　また、請求項５に係る発明は、前記請求項２~請求項４の何れか１項に記載の重ね放電型内燃機関用点火装置において、前記重畳電圧生成動作制御手段は、生成する重畳電圧生成用交流の波高値を変化させることで、多段倍電圧整流手段へ出力する電力を調整するようにしたことを特徴とする。
　また、請求項６に係る発明は、前記請求項２~請求項４の何れか１項に記載の重ね放電型内燃機関用点火装置において、前記重畳電圧生成動作制御手段は、矩形波交流のＯＮ／ＯＦＦデューティー比を変化させるＰＷＭ制御によって、多段倍電圧整流手段へ出力する電力を調整するようにしたことを特徴とする。
　また、請求項７に係る発明は、前記請求項１に記載の重ね放電型内燃機関用点火装置において、前記重畳電圧生成動作制御手段が出力する重畳電圧生成用交流の電圧値を変化させることにより、前記多段倍電圧整流手段より出力される電圧を調整できるようにしたことを特徴とする。
　また、請求項８に係る発明は、前記請求項１又は請求項７に記載の重ね放電型内燃機関用点火装置において、前記重畳電圧生成動作制御手段の駆動時間を任意に制御できる重ね時間制御手段を備え、前記多段倍電圧整流手段によって生成された直流高電圧の重ね時間を任意に変更できるようにしたことを特徴とする。
　また、請求項９に係る発明は、前記請求項１又は請求項７に記載の重ね放電型内燃機関用点火装置において、前記多段倍電圧整流手段は、前記点火コイルと同一のケース内へ収納するようにしたことを特徴とする。 In order to solve the above-described problem, the invention according to claim 1 is configured to block the current of the primary coil of the ignition coil in response to the ignition signal, induce a high voltage in the secondary coil, and have the same polarity as the high voltage. In an ignition device for a multi-discharge internal combustion engine that superimposes a voltage, causes a spark discharge in a discharge gap of an ignition plug, and ignites an air-fuel mixture in a combustion chamber, at the timing of high voltage induction of a secondary coil based on the ignition signal A superimposed voltage generating operation control means for outputting a superimposed voltage generating alternating current of a required voltage / required frequency, and a voltage doubler rectifier circuit operating within a cycle of the superimposed voltage generating alternating current supplied from the superimposed voltage generating operation control means. A multi-stage voltage doubler rectifier that combines multiple stages and outputs a DC high voltage that is several times the peak value of the input peak value, and outputs the DC high voltage output from the multi-stage voltage doubler rectifier. Superimposing a high voltage of the same polarity induced in Le of the secondary coil, characterized in that so as to perform overlapping discharge by applying to the spark plug.
The invention according to claim 2 interrupts the current of the primary coil of the ignition coil in response to the ignition signal, induces a high voltage in the secondary coil, and superimposes a voltage having the same polarity as the high voltage, In an ignition device for a multi-discharge internal combustion engine that generates a spark discharge in a discharge gap of a plug and ignites an air-fuel mixture in a combustion chamber, a required voltage and a required frequency at the timing of high voltage induction of a secondary coil based on the ignition signal Of the superimposed voltage generation AC and the superimposed voltage generation operation control means capable of increasing / decreasing the output power based on an external instruction, and the superimposed voltage generation AC supplied from the superimposed voltage generation operation control means. A multi-stage voltage doubler rectifier that combines multiple voltage rectifier circuits operating in a cycle and outputs a DC high voltage that is multiple times the number of input voltages; and from the multi-stage voltage doubler rectifier The DC high voltage to be applied is superposed with the same polarity as the high voltage induced in the secondary coil of the ignition coil, applied to the ignition plug to cause overlap discharge, and superposed by the multistage voltage doubler rectifier While detecting the overlap current value, it compares the preset overlap current set value with the actually detected overlap current detection value, and if the overlap current detection value is lower than the overlap current set value, the output increase instruction signal Is provided to the superimposed voltage generation operation control means, and when the overlap current detection value is higher than the overlap current set value, feedback control means is provided for outputting an output reduction instruction signal to the overlap voltage generation operation control means, and the feedback Adjusting the power output from the superimposed voltage generation operation control means to the multi-stage voltage doubler rectification means based on an output increase instruction signal or output reduction instruction signal from the control means. , Increase or decrease the DC high voltage output from the multistage voltage doubler rectifier unit, characterized in that to perform the feedback control to approximate to the current setting value repeatedly superimposed current detection value.
According to a third aspect of the present invention, in the ignition device for an overlapped discharge internal combustion engine according to the second aspect, the superimposed voltage generation operation control means receives an output increase instruction signal or an output reduction instruction signal from the feedback control means. The output is increased / decreased by a predetermined amount each time the signal is received.
According to a fourth aspect of the present invention, in the ignition device for a multi-discharge internal combustion engine according to the second aspect, the feedback control means increases or decreases the output according to the difference between the superposed current detection value and the superposed current set value. And an output increase instruction signal or an output decrease instruction signal including the determined output increase / decrease amount is transmitted to the superimposed voltage generation operation control means, and the superimposed voltage generation operation control means increases the output from the feedback control means. The output power is increased or decreased according to the instruction signal or the output reduction instruction signal.
Further, in the invention according to claim 5, in the ignition device for an overlap discharge type internal combustion engine according to any one of claims 2 to 4, the superimposed voltage generation operation control means generates the superimposed voltage to be generated. The power output to the multi-stage voltage doubler rectifying means is adjusted by changing the peak value of the AC for use.
The invention according to claim 6 is the ignition device for an overlap discharge type internal combustion engine according to any one of claims 2 to 4, wherein the superimposed voltage generation operation control means is a rectangular wave AC ON. The power output to the multistage voltage doubler rectifier is adjusted by PWM control that changes the / OFF duty ratio.
According to a seventh aspect of the present invention, in the ignition apparatus for a supercharging internal combustion engine according to the first aspect, by changing the voltage value of the superimposed voltage generating AC output from the superimposed voltage generating operation control means. The voltage output from the multi-stage voltage doubler rectifier can be adjusted.
The invention according to claim 8 is the overlap time control means capable of arbitrarily controlling the drive time of the overlap voltage generation operation control means in the ignition device for the overlap discharge type internal combustion engine according to claim 1 or claim 7. And the superposition time of the DC high voltage generated by the multi-stage voltage doubler rectifier can be arbitrarily changed.
The invention according to claim 9 is the ignition device for a multiple discharge type internal combustion engine according to claim 1 or 7, wherein the multistage voltage doubler rectifier is housed in the same case as the ignition coil. It is characterized by doing so.

　請求項１に係る発明によれば、前記点火信号に基づく二次コイルの高電圧誘起のタイミングで、所要電圧・所要周波数の重畳電圧生成用交流を出力する重畳電圧生成動作制御手段と、前記重畳電圧生成動作制御手段から供給される重畳電圧生成用交流の周期内で作動する倍電圧整流回路を多段に組み合わせ、入力尖頭値の段数倍の直流高電圧を出力するようにした多段倍電圧整流手段と、を備え、前記多段倍電圧整流手段から出力される直流高電圧を、前記点火コイルの二次コイルに誘起する高電圧と同極性で重畳し、点火プラグに印加することにより重ね放電を行わせるようにしたので、多段倍電圧整流手段を構成する各倍電圧整流回路に用いるダイオードおよびコンデンサの耐圧は重畳電圧生成用交流出力の２倍程度で十分であり、また、従来の重ね放電型内燃機関用点火装置の充放電用コンデンサの様な大容量のものは必要ないことから、コスト抑制および部品の小型化が可能になり、無理なく狭小な車載スペースへ設置できる。
　請求項２に係る発明によれば、前記点火信号に基づく二次コイルの高電圧誘起のタイミングで、所要電圧・所要周波数の重畳電圧生成用交流を出力すると共に、外部よりの指示に基づいて出力する電力を増減可能な重畳電圧生成動作制御手段と、前記重畳電圧生成動作制御手段から供給される重畳電圧生成用交流の周期内で作動する倍電圧整流回路を多段に組み合わせ、入力電圧の段数倍の直流高電圧を出力するようにした多段倍電圧整流手段と、を備え、前記多段倍電圧整流手段から出力される直流高電圧を、前記点火コイルの二次コイルに誘起する高電圧と同極性で重畳し、点火プラグに印加することにより重ね放電を行わせ、前記多段倍電圧整流手段により重畳された重ね電流値を検出すると共に、予め設定された重ね電流設定値と実際に検出された重ね電流検出値とを比較し、重ね電流検出値が重ね電流設定値よりも低い場合には出力増加指示信号を前記重畳電圧生成動作制御手段へ出力し、重ね電流検出値が重ね電流設定値よりも高い場合には出力低減指示信号を前記重畳電圧生成動作制御手段へ出力するフィードバック制御手段を設け、前記フィードバック制御手段からの出力増加指示信号または出力低減指示信号に基づいて、前記重畳電圧生成動作制御手段が多段倍電圧整流手段へ出力する電力を調整することで、多段倍電圧整流手段から出力される直流高電圧を増減させ、重ね電流検出値を重ね電流設定値へ近づけるフィードバック制御を行うようにしたので、多段倍電圧整流手段を構成する各倍電圧整流回路に用いるダイオードおよびコンデンサの耐圧は重畳電圧生成用交流出力の２倍程度で十分であり、また、従来の重ね放電型内燃機関用点火装置の充放電用コンデンサの様な大容量のものは必要ないことから、コスト抑制および部品の小型化が可能になり、無理なく狭小な車載スペースへ設置できる。しかも、フィードバック制御手段によるフィードバック制御により、実際に重畳する直流高電圧を増減させて、安定した放電を行うのに必要十分な重ね電流の供給を維持できる。
　また、請求項３に係る発明によれば、前記重畳電圧生成動作制御手段は、前記フィードバック制御手段から出力増加指示信号もしくは出力低減指示信号を受ける毎に、予め定めた規定量だけ出力を増減させるようにしたので、フィードバック制御手段を比較的簡易に構成できる。
　また、請求項４に係る発明によれば、前記フィードバック制御手段は、重ね電流検出値と重ね電流設定値との差に応じて出力増減量を決定すると共に、決定した出力増減量を含む出力増加指示信号もしくは出力低減指示信号を前記重畳電圧生成動作制御手段へ送信し、前記重畳電圧生成動作制御手段は、フィードバック制御手段からの出力増加指示信号もしくは出力低減指示信号に応じて、出力する電力を増減するようにしたので、急激に生じた重ね電流検出値の変化に対しても迅速に対応できる。
　また、請求項５に係る発明によれば、前記重畳電圧生成動作制御手段は、生成する重畳電圧生成用交流の波高値を変化させることで、多段倍電圧整流手段へ出力する電力を調整するようにしたので、交流生成用の昇圧機能を使って出力低減もしくは出力増加に対応できる。
　また、請求項６に係る発明によれば、前記重畳電圧生成動作制御手段は、矩形波交流のＯＮ／ＯＦＦデューティー比を変化させるＰＷＭ制御によって、多段倍電圧整流手段へ出力する電力を調整するようにしたので、所定波高値の矩形波交流を使って出力低減もしくは主流直増加に対応できる。
　また、請求項７に係る発明によれば、前記重畳電圧生成動作制御手段が出力する重畳電圧生成用交流の電圧値を変化させることにより、前記多段倍電圧整流手段より出力される電圧を調整できるようにしたので、混合気の状態に適した特性の放電を行えるような放電電流を流すことができる。
　また、請求項８に係る発明によれば、前記重畳電圧生成動作制御手段の駆動時間を任意に制御できる重ね時間制御手段を備え、前記多段倍電圧整流手段によって生成された直流高電圧の重ね時間を任意に変更できるようにしたので、混合気の状態に適した特性の放電を行えるような重ね時間だけ放電電流を継続させることができる。
　加えて、請求項７および請求項８の構成を併せて採用した発明によれば、重ね時間と重ね電流を任意に変更できるので、混合気の状態に最適な放電時間および最適な放電エネルギーを供給でき、必要以上の放電エネルギーが供給されて無駄な電力消費が続いたり、点火プラグ電極の消耗を早めてしまうといった問題を回避できる。
　また、請求項９に係る発明によれば、前記多段倍電圧整流手段は、前記点火コイルと同一のケース内へ収納するようにしたので、多段倍電圧整流手段から点火コイルへの高電圧供給線をケース内に納めることができ、直流高電圧線の引き回しが不要になって高耐圧の配線材料や配線スペースの確保も不要になる。 According to the first aspect of the present invention, the superimposed voltage generating operation control means for outputting the superimposed voltage generating alternating current of the required voltage / required frequency at the timing of the high voltage induction of the secondary coil based on the ignition signal, and the superimposing Multi-stage voltage doubler that combines multiple voltage rectifier circuits that operate within the period of the superimposed voltage generation AC supplied from the voltage generation operation control means, and outputs a DC high voltage that is the number of stages of the input peak value. Rectifying means, and the DC high voltage output from the multi-stage voltage doubler rectifying means is superimposed with the same polarity as the high voltage induced in the secondary coil of the ignition coil, and applied to the spark plug for overlap discharge Therefore, the withstand voltage of the diode and capacitor used in each voltage doubler rectifier circuit constituting the multistage voltage doubler rectifier is sufficient to be about twice that of the superimposed voltage generating AC output. Because it is not necessary that a large capacity such as charging and discharging capacitor of a conventional lap discharge type ignition device for an internal combustion engine, enables miniaturization of cost containment and components, it can be installed to reasonably narrow automotive space.
According to the second aspect of the present invention, at the timing of inducing the high voltage of the secondary coil based on the ignition signal, the superimposed voltage generating alternating current of the required voltage / required frequency is output and output based on an instruction from the outside. Superimposed voltage generation operation control means that can increase or decrease the power to be combined with a double voltage rectifier circuit that operates within the cycle of the superimposed voltage generation AC supplied from the superimposed voltage generation operation control means in multiple stages, and the number of input voltage stages And a multi-stage voltage doubler rectifier that outputs a double DC high voltage, and the DC high voltage output from the multi-stage voltage doubler rectifier is the same as the high voltage induced in the secondary coil of the ignition coil. Overlap with polarity and apply to the spark plug to cause overlap discharge, detect the overlap current value superimposed by the multistage voltage doubler rectifier, and When the overlap current detection value is lower than the overlap current set value, an output increase instruction signal is output to the superimposed voltage generation operation control means, and the overlap current detection value is overlapped. Provided with feedback control means for outputting an output reduction instruction signal to the superimposed voltage generation operation control means when higher than the current set value, based on the output increase instruction signal or the output reduction instruction signal from the feedback control means, Feedback to increase or decrease the DC high voltage output from the multi-stage voltage doubler rectifier by adjusting the power output from the superposed voltage generation operation control means to the multi-stage voltage doubler rectifier, thereby bringing the overlap current detection value closer to the overlap current set value Since the control is performed, the withstand voltages of the diodes and capacitors used in each voltage doubler rectifier circuit constituting the multistage voltage doubler rectifier are superimposed voltage. Twice as much as the AC output for generation is sufficient, and it is not necessary to have a large capacity like the charge / discharge capacitor of the conventional ignition device for a multi-discharge internal combustion engine. Can be installed in a narrow vehicle space without difficulty. In addition, the feedback control by the feedback control means can increase or decrease the DC high voltage that is actually superimposed, and maintain the supply of sufficient overlap current necessary for stable discharge.
According to a third aspect of the invention, the superimposed voltage generation operation control means increases or decreases the output by a predetermined specified amount every time an output increase instruction signal or an output reduction instruction signal is received from the feedback control means. Since it did in this way, a feedback control means can be comprised comparatively easily.
According to the invention of claim 4, the feedback control means determines the output increase / decrease amount according to the difference between the overlap current detection value and the overlap current set value, and the output increase includes the determined output increase / decrease amount. An instruction signal or an output reduction instruction signal is transmitted to the superimposed voltage generation operation control means, and the superimposed voltage generation operation control means outputs power to be output in response to the output increase instruction signal or the output reduction instruction signal from the feedback control means. Since it is increased or decreased, it is possible to quickly cope with a sudden change in the detected overlap current value.
According to the invention of claim 5, the superimposed voltage generation operation control means adjusts the power output to the multistage voltage doubler rectifier means by changing the peak value of the generated superimposed voltage generating alternating current. Therefore, it is possible to cope with output reduction or output increase using the boost function for AC generation.
According to the invention of claim 6, the superimposed voltage generation operation control means adjusts the power output to the multistage voltage doubler rectification means by PWM control that changes the ON / OFF duty ratio of the rectangular wave AC. Therefore, it is possible to cope with output reduction or mainstream direct increase using a rectangular wave alternating current with a predetermined peak value.
According to the seventh aspect of the invention, the voltage output from the multi-stage voltage doubler rectifier can be adjusted by changing the voltage value of the superimposed voltage generating AC output from the superimposed voltage generating operation control unit. Since it did in this way, the discharge current which can perform the discharge of the characteristic suitable for the state of air-fuel mixture can be sent.
Further, according to the invention according to claim 8, the superposition time control means capable of arbitrarily controlling the drive time of the superposition voltage generation operation control means is provided, and the superposition time of the DC high voltage generated by the multistage voltage doubler rectification means. Since the discharge current can be arbitrarily changed, the discharge current can be continued for an overlap time that allows discharge having characteristics suitable for the state of the air-fuel mixture.
In addition, according to the invention adopting the configurations of claim 7 and claim 8 together, since the overlap time and the overlap current can be arbitrarily changed, the optimum discharge time and the optimum discharge energy are supplied to the mixture state. In addition, it is possible to avoid problems such as wasteful power consumption due to excessive discharge energy being supplied and rapid consumption of the spark plug electrode.
According to the invention of claim 9, since the multistage voltage doubler rectifier is housed in the same case as the ignition coil, a high voltage supply line from the multistage voltage doubler rectifier to the ignition coil. Can be accommodated in the case, and it is not necessary to route the DC high-voltage line, and it is not necessary to secure a high-breakdown-voltage wiring material and wiring space.

　図１は、本発明の実施形態として示す重ね放電型内燃機関用点火装置の概略構成図である。
　図２は、図１の重ね放電型内燃機関用点火装置における点火時の動作波形図である。 FIG. 1 is a schematic configuration diagram of an ignition device for a multi-discharge internal combustion engine shown as an embodiment of the present invention.
FIG. 2 is an operation waveform diagram at the time of ignition in the ignition device for the multiple discharge internal combustion engine of FIG.

　次に、添付図面に基づいて、本発明に係る重ね放電型内燃機関用点火装置の実施形態を詳細に説明する。 Next, an embodiment of an ignition device for a multiple discharge internal combustion engine according to the present invention will be described in detail with reference to the accompanying drawings.

　図１は、本発明に係る重ね放電型内燃機関用点火装置を車両のエンジン点火装置に適用した一実施形態の概略構成を示すもので、点火コイル１（例えば、一次コイル１ａ、二次コイル１ｂ、鉄心１ｃ、スイッチング素子１ｄより成る）によって、点火プラグ２の放電間隙ｇに火花放電を起こし、図示を省略した車両エンジンの燃焼室の混合気に点火するものである。
　例えば、エンジン制御装置（ＥＣＵ）からの点火信号により、点火コイル１のスイッチング素子１ｄがＯＮになることで、図示を省略した車載バッテリーから直流電圧ＶＢが供給されている一次コイル１ａに電流が流れ、その後、点火信号のパルス立ち下がりでスイッチング素子１ｄがオフとなり、一次コイル１ａの電流を遮断し、二次コイル１ｂに誘起される高電圧によって点火プラグ２の放電間隙間ｇに火花放電を起こす。
　しかして、本実施形態に係る重ね放電型内燃機関用点火装置においては、上記二次コイル１ｂに誘起される高電圧に重畳する電圧を生成するため、「点火信号に基づく二次コイルの高電圧誘起のタイミングで、所要電圧・所要周波数の重畳電圧生成用交流を出力すると共に、外部よりの指示に基づいて出力する電力を増減可能な重畳電圧生成動作制御手段」としてのＤＣ−ＡＣ昇圧回路３から重畳電圧生成用交流（例えば、ＡＣ２００Ｖ）を「重畳電圧生成動作制御手段から供給される重畳電圧生成用交流の周期内で作動する倍電圧整流回路を多段に組み合わせ、入力電圧の段数倍の直流高電圧を出力するようにした多段倍電圧整流手段」としての多段倍電圧整流回路４へ供給し、多段倍電圧整流回路４から直流高電圧（例えば、ＤＣ１．２ｋＶ）を出力させ、この直流高電圧を二次コイル１ｂの誘起電圧に重畳することで、点火プラグ２に生じさせる放電電流の大きさや放電時間を調整するのである。なお、二次コイル１ｂと接地点の間には、二次コイル１ｂ側がアノード、接地側がカソードとなるように高圧ダイオード５を設けてあり、多段倍電圧整流回路４から出力される直流高電圧のプラス側を高圧ダイオード５のカソード側に、マイナス側を高圧ダイオード５のアノード側に接続することで、二次コイル１ｂに誘起する高電圧と同極性で重畳するようにした。
　上記ＤＣ−ＡＣ昇圧回路３は、点火信号によって点火コイル１のスイッチング素子１ｄがオフになるタイミング（例えば、点火信号のパルス立ち下がりの検出タイミング）で動作を開始し、所定の重ね時間経過後にタイマ等で動作を停止するものでも良いが、内燃機関の燃焼特性に応じた重ね時間に調整することが容易なように、「重畳電圧生成動作制御手段の駆動時間を任意に制御できる重ね時間制御手段」としての重ね時間制御回路６を設け、この重ね時間制御回路６に対する設定により、重ね時間（ＤＣ−ＡＣ昇圧回路３から重畳電圧生成用交流を出力させる時間）を任意に変化させることが出来るようにした。
　また、点火プラグ２の放電経路適所（例えば、高圧ダイオード５と接地点との間）に電流検出用抵抗７を設け、実際に流れた放電電流を重ね電流検出・比較回路８にて検出できるようにする。この重ね電流検出・比較回路８は、外部から入力される重ね電流設定信号に基づいて重ね電流設定値を記憶しておくことができ、「多段倍電圧整流手段により重畳された重ね電流値を検出すると共に、予め設定された重ね電流設定値と実際に検出された重ね電流検出値とを比較し、重ね電流検出値が重ね電流設定値よりも低い場合には出力増加指示信号を前記重畳電圧生成動作制御手段へ出力し、重ね電流検出値が重ね電流設定値よりも高い場合には出力低減指示信号を前記重畳電圧生成動作制御手段へ出力するフィードバック制御手段」として機能する。
　すなわち、重ね電流検出・比較回路８からの出力増加指示信号または出力低減指示信号に基づいて、ＤＣ−ＡＣ昇圧回路３が多段倍電圧整流回路４へ出力する電力（重畳電圧生成用交流の波高値）を調整（例えば、ＡＣ２００Ｖを基準値として、±αＶの範囲で増減）することで、多段倍電圧整流回路４から出力される直流高電圧を増減（例えば、１２００−６αＶ~１２００＋６αｋＶの範囲で増減）させ、重ね電流検出値を重ね電流設定値へ近づけるフィードバック制御を行うのである。
　なお、重ね電流検出・比較回路８が検出する放電電流には、二次コイル１ｂに誘起する高電圧に基づくスパイク状の放電電流も含んでいるので、例えば、放電電流の検出タイミングから所定時間経過後に検出される電流値を重ね電流検出値として取り込み、重ね電流設定値との比較に用いるようにすれば良い。 FIG. 1 shows a schematic configuration of an embodiment in which an ignition device for a multiple discharge type internal combustion engine according to the present invention is applied to an engine ignition device for a vehicle. An ignition coil 1 (for example, a primary coil 1a, a secondary coil 1b) is shown. , The iron core 1c and the switching element 1d) cause a spark discharge in the discharge gap g of the spark plug 2, and ignites the air-fuel mixture in the combustion chamber of the vehicle engine (not shown).
For example, when the switching element 1d of the ignition coil 1 is turned on by an ignition signal from the engine control unit (ECU), a current flows to the primary coil 1a to which the DC voltage VB is supplied from a vehicle battery (not shown). Thereafter, the switching element 1d is turned off at the falling edge of the ignition signal, the current of the primary coil 1a is cut off, and a spark discharge is caused in the gap g between the discharges of the spark plug 2 by the high voltage induced in the secondary coil 1b. .
Therefore, in the ignition apparatus for a multi-discharge internal combustion engine according to this embodiment, in order to generate a voltage to be superimposed on the high voltage induced in the secondary coil 1b, the “high voltage of the secondary coil based on the ignition signal” is generated. DC-AC booster circuit 3 serving as a superimposed voltage generation operation control means that outputs alternating current for generating a superimposed voltage having a required voltage / required frequency at the induction timing and that can increase or decrease the output power based on an external instruction. From the superposition voltage generation AC (for example, AC200V) "combining multiple voltage rectifier circuits that operate within the superposition voltage generation AC cycle supplied from the superposition voltage generation operation control means in multiple stages, The multi-stage voltage doubler rectifier circuit 4 serving as a “multi-stage voltage doubler rectifier that outputs a DC high voltage” is supplied to the multi-stage voltage doubler rectifier circuit 4 and the DC high voltage (for example, DC1.2 V) is output, by superimposing the DC high voltage to the induced voltage of the secondary coil 1b, is to adjust the size and the discharge time of the discharge current that causes the ignition plug 2. A high voltage diode 5 is provided between the secondary coil 1b and the ground point so that the secondary coil 1b side is an anode and the ground side is a cathode, and the DC high voltage output from the multistage voltage doubler rectifier circuit 4 is provided. By connecting the positive side to the cathode side of the high-voltage diode 5 and the negative side to the anode side of the high-voltage diode 5, the high voltage induced in the secondary coil 1 b is superimposed with the same polarity.
The DC-AC booster circuit 3 starts operating at the timing when the switching element 1d of the ignition coil 1 is turned off by the ignition signal (for example, the detection timing of the pulse falling of the ignition signal), and after a predetermined overlap time has elapsed, Although the operation may be stopped by, for example, “the overlap time control means that can arbitrarily control the drive time of the overlap voltage generation operation control means so that the overlap time according to the combustion characteristics of the internal combustion engine can be easily adjusted. The superposition time control circuit 6 is provided, and the superposition time (time for outputting the superposition voltage generation AC from the DC-AC booster circuit 3) can be arbitrarily changed by setting the superposition time control circuit 6. I made it.
Further, a current detection resistor 7 is provided at an appropriate discharge path of the spark plug 2 (for example, between the high voltage diode 5 and the grounding point) so that the actually flowing discharge current can be detected by the overlapping current detection / comparison circuit 8. To. This overlap current detection / comparison circuit 8 can store the overlap current setting value based on the overlap current setting signal input from the outside, and “detects the overlap current value superimposed by the multi-stage voltage doubler rectifier. At the same time, the preset overlap current setting value is compared with the actually detected overlap current detection value. When the overlap current detection value is lower than the overlap current set value, the output increase instruction signal is generated. When the overlap current detection value is higher than the overlap current set value, it functions as feedback control means for outputting an output reduction instruction signal to the superimposed voltage generation operation control means ”.
That is, based on the output increase instruction signal or the output decrease instruction signal from the overlap current detection / comparison circuit 8, the power (the peak value of the superimposed voltage generation AC) output from the DC-AC booster circuit 3 to the multistage voltage doubler rectifier circuit 4. ) (For example, increase / decrease within the range of ± αV with AC200V as the reference value), increase / decrease the DC high voltage output from the multistage voltage doubler rectifier circuit 4 (for example, increase / decrease within the range of 1200-6αV to 1200 + 6αkV) ) And feedback control is performed to bring the overlap current detection value closer to the overlap current set value.
The discharge current detected by the overlap current detection / comparison circuit 8 includes a spike-like discharge current based on a high voltage induced in the secondary coil 1b. For example, a predetermined time has elapsed from the detection timing of the discharge current. A current value detected later may be taken in as an overlap current detection value and used for comparison with the overlap current set value.

　ここで、図２の動作波形を参照しつつ、本実施形態に係る重ね放電型内燃機関用点火装置の各部動作を説明する。
　先ず、点火信号として所定幅のパルスが点火コイル１に入力されると、パルス立ち上がりによってスイッチング素子１ｄがＯＮとなり、一次コイル１ａに一次電流が流れ始めるが、点火信号のパルス立ち下がりによってスイッチング素子１ｄがオフになると、一次コイル１ａに電流が流れなくなるため、点火コイル１の二次コイル１ｂには瞬時的に大きな二次電圧が誘起される。
　上記のように、二次コイル１ｂに二次電圧が誘起されるタイミング（点火信号のパルス立ち下がりのタイミング）で重ね時間制御回路６がＤＣ−ＡＣ昇圧回路３へ出力する重ね時間制御信号をＯＮにし（例えば、信号レベルをＬからＨに変更し）、ＤＣ−ＡＣ昇圧回路３による重畳電圧生成用交流の出力を開始させる。ＤＣ−ＡＣ昇圧回路３は、重ね時間制御回路６からの重ね時間制御信号がＯＦＦになる（信号レベルがＨからＬに変わる）まで重畳電圧生成用交流の出力を続けるので、その間継続して多段倍電圧整流回路４から直流高電圧が出力されることとなる。
　なお、ＤＣ−ＡＣ昇圧回路３は、車載バッテリーの直流電圧ＶＢ（例えば、ＤＣ１２Ｖ）をＡＣ２００Ｖにして出力するものを例示したが、これに限定されるものではなく、重畳電圧生成用交流の電圧値は任意に設定して構わない。
　上記のように構成したＤＣ−ＡＣ昇圧回路３からの重畳電圧生成用交流を受ける多段倍電圧整流回路４は、入力された交流の尖頭値の２倍の直流電圧を出力する倍電圧整流回路を３段としたもので、ＡＣ２００Ｖの入力に対して６倍圧となるＤＣ１．２ｋＶの直流高電圧を得ることができる。
　なお、多段倍電圧整流回路４に用いる倍電圧整流回路は既知のもので良く、図１に示す３段倍電圧整流回路においては、ダイオードＤ１によりキャパシタＣ１に充電し、ダイオードＤ２によりキャパシタＣ２に充電し、以下同様にしてダイオードＤ３、ダイオードＤ４，ダイオードＤ５，ダイオードＤ６によりキャパシタＣ３，キャパシタＣ４，キャパシタＣ５，キャパシタＣ６に充電された結果、直列に接続されているキャパシタＣ２，キャパシタＣ４，キャパシタＣ６は、それぞれ入力尖頭値のおよそ２倍に充電されるので、６倍圧（キャパシタの充電電圧×２×段数）の直流を得ることができる。
　すなわち、図１に示すような多段倍電圧整流回路４を用いて直流高電圧を取得する場合、各倍電圧整流回路のダイオードＤ１~Ｄ６およびキャパシタＣ１~Ｃ６の耐圧は、何れも重畳電圧生成用交流の電圧値の２倍以上あれば問題ないので、従来の重ね放電型内燃機関用点火装置の充放電用コンデンサの様な大容量は必要なく、部品の小型化およびコスト低減が可能になる。なお、多段倍電圧整流回路４は３段のものに限定されず、２段あるいは４段以上でも構わない。
　上記のようにして多段倍電圧整流回路４から得られるＤＣ１．２ｋＶの直流高電圧は、重ね時間制御回路６の重ね時間制御信号がＯＦＦになる（信号レベルがＨからＬに変わる）まで継続して出力される。但し、多段倍電圧整流回路４から得られた直流高電圧を二次コイル１ｂに誘起される高電圧に重畳するとき、二次コイル１ｂに誘起される高電圧と同極性で重畳する必要があるため、放電電極への重畳電圧は、多段倍電圧整流回路出力の反転波形となる。
　以上のように、本実施形態に係る重ね放電型内燃機関用点火装置においては、多段倍電圧整流回路４から出力される直流高電圧を点火コイル１の二次コイル１ｂに誘起する高電圧と同極性で重畳することで、点火プラグ２の放電波形は、図２に示すように、点火初期の大電流が流れた後も、多段倍電圧整流回路４からの直流高電圧が重畳されていることで、重ね時間制御回路６により制御される重ね時間が経過するまで点火プラグ２の放電が継続し、重ね電流設定値に等しい重ね電流が流れ続ける。
　しかも、本実施形態に係る重ね放電型内燃機関用点火装置においては、重畳電圧生成用交流を出力するＤＣ−ＡＣ昇圧回路３と、この重畳電圧生成用交流を受けて直流高電圧を生成する多段倍電圧整流回路４とを用いる構成としたので、重畳電圧生成動作制御手段としてのＤＣ−ＡＣ昇圧回路３が出力する重畳電圧生成用交流の電圧値を高くしたり、或いは低くしたりすることにより、多段倍電圧整流手段としての多段倍電圧整流回路４より出力される電圧を高くしたり低くしたり調整できるので、混合気の状態に適した特性の放電を行えるような放電電流を流すことができる。
　さらに、重畳電圧生成動作制御手段としてのＤＣ−ＡＣ昇圧回路３の駆動時間は、重ね時間制御手段としての重ね時間制御回路６によって任意に制御できるので、多段倍電圧整流回路４によって生成された直流高電圧の重ね時間を長くしたり、短くしたり、任意に変更でき、混合気の状態に適した特性の放電を行えるような重ね時間だけ放電電流を継続させることができる。
　加えて、ＤＣ−ＡＣ昇圧回路３による放電エネルギーの調整機能と、重ね時間制御回路６による重ね時間の調整機能を併せて使えば、重ね時間と重畳する放電エネルギーを任意に変更できるので、混合気の状態に最適な放電時間および最適な放電エネルギーを供給でき、必要以上の放電エネルギーが供給されて無駄な電力消費が続いたり、点火プラグ２の電極の消耗を早めてしまうといった問題を回避できる。
　また、多段倍電圧整流回路４は、小型の部品で構成することが出来るので、点火コイル１と同一のケース内へ収納することが容易である。しかも、多段倍電圧整流回路４と高圧ダイオード５を点火コイル１と同一のケース内へ収納しておけば、多段倍電圧整流回路４からの高電圧供給線をケース内に納めることができ、直流高電圧線の引き回しが不要になって高耐圧の配線材料や配線スペースの確保も不要になる。
　なお、重ね放電型内燃機関用点火装置の設計上は、ＡＣ２００Ｖの重畳電圧生成用交流をＤＣ−ＡＣ昇圧回路３から多段倍電圧整流回路４へ供給することで多段倍電圧整流回路４から出力されるＤＣ１．２ｋＶを放電電極へ重畳すると、重ね電流設定値にほぼ等しい重ね電流が検出されるはずであるが、回路上の器差やパーツの経年劣化等に起因して重ね電流設定値と同一とはみなせない程に検出電圧が低かったり、高かったりする可能性もある。このように、ＤＣ−ＡＣ昇圧回路３から基準となる重畳電圧生成用交流を多段倍電圧整流回路４へ供給しても重ね電流検出値が重ね電流設定値と一致しない場合（例えば、予め定めた許容誤差を超える差が生じていた場合）には、重ね電流検出・比較回路８がこれを検知し、フィードバック制御を行うことで、重ね電流検出値を重ね電流設定値へ近づけるのである。
　このフィードバック制御の一例を具体的に説明すると、重ね電流検出・比較回路が重ね電流検出値と重ね電流設定値を比較した結果、重ね電流検出値の絶対値が重ね電流設定値の絶対値よりも小さかった場合、重ね電流検出・比較回路８がＤＣ−ＡＣ昇圧回路３へ出力増加指示信号を出力し、これを受けたＤＣ−ＡＣ昇圧回路３は、予め定めた規定量（例えば、１Ｖ）だけ重畳電圧生成用交流の波高値を高くし、多段倍電圧整流回路４の出力電圧を増加（例えば、加算電圧の６倍となる約６Ｖだけ増加）させ、放電電極への重畳電圧を高めて重ね電流を増加させる。これによって増加した重ね電流を重ね電流検出・比較回路８が検出・比較し、未だ重ね電流検出値が重ね電流設定値に満たない場合には、重ね電流検出・比較回路８が出力増加指示信号をＤＣ−ＡＣ昇圧回路３へ出力して重畳電圧生成用交流の波高値を更に微増させる。重ね電流検出値と重ね電流設定値とが一致すれば、重ね電流検出・比較回路８からＤＣ−ＡＣ昇圧回路３へ出力増加指示信号が出力されることはないため、ＤＣ−ＡＣ昇圧回路３から出力される重畳電圧生成用交流の波高値はそのまま保持されるので、多段倍電圧整流回路４から放電電極への重畳電圧もそのまま保持され、重ね電流設定値と一致した重ね電流が保持される。
　逆に、重ね電流検出・比較回路が重ね電流検出値と重ね電流設定値を比較した結果、重ね電流検出値の絶対値が重ね電流設定値の絶対値よりも大きかった場合、重ね電流検出・比較回路８がＤＣ−ＡＣ昇圧回路３へ出力低減指示信号を出力し、これを受けたＤＣ−ＡＣ昇圧回路３は、予め定めた規定量（例えば、１Ｖ）だけ重畳電圧生成用交流の波高値を低くし、多段倍電圧整流回路４の出力電圧を低減（例えば、加算電圧の６倍となる約６Ｖだけ低減）させ、放電電極への重畳電圧を下げて重ね電流を低減させる。これによって低減された重ね電流を重ね電流検出・比較回路８が検出・比較し、未だ重ね電流検出値が重ね電流設定値を上回っていた場合には、重ね電流検出・比較回路８が出力低減指示信号をＤＣ−ＡＣ昇圧回路３へ出力して重畳電圧生成用交流の波高値を更に微減させる。重ね電流検出値と重ね電流設定値とが一致すれば、重ね電流検出・比較回路８からＤＣ−ＡＣ昇圧回路３へ出力低減指示信号が出力されることはないため、ＤＣ−ＡＣ昇圧回路３から出力される重畳電圧生成用交流の波高値はそのまま保持されるので、多段倍電圧整流回路４から放電電極への重畳電圧もそのまま保持され、重ね電流設定値と一致した重ね電流が保持される。
　なお、重ね電流検出・比較回路８によるフィードバック制御の基準となる重ね電流設定値は、外部から重ね電流設定信号を入力することで任意に設定変更できるようにしたので、重ね放電型内燃機関用点火装置が適用されるエンジンの特性に応じた最適の重ね電流値を設定できるので、装置としての汎用性を高められる。
　また、重ね電流検出・比較回路８とＤＣ−ＡＣ昇圧回路３とで実現されるフィードバック制御は、上述した手法に限らず、公知既存の手法を適宜に使用して構わない。例えば、重ね電流設定値と重ね電流検出値との差分と、この差分を埋めるためにＤＣ−ＡＣ昇圧回路３に指示する出力増減値とを対応付けた対応表あるいは演算式を重ね電流検出・比較回路８に記憶させておき、この対応表あるいは演算式から決定した出力増減量を含む信号（出力増加指示信号もしくは出力低減指示信号）を重ね電流検出・比較回路８からＤＣ−ＡＣ昇圧回路３へ送信し、これを受けたＤＣ−ＡＣ昇圧回路３が指示情報に基づいて重畳電圧生成用交流の波高値を変化させ、多段倍電圧整流回路４から放電電極への充電電圧を一気に増減させることで、迅速に重ね電流を設定値へ近づけるようにしても構わない。
　さらに、上述した重ね放電型内燃機関用点火装置の実施形態においては、ＤＣ−ＡＣ昇圧回路３から供給する重畳電圧生成用交流の波高値を変化させることで多段倍電圧整流回路４への供給電力を変化させ、多段倍電圧整流回路４の各キャパシタＣ１~Ｃ６の充電電圧を増減させて、放電電極への重畳電圧を増減するものとしたが、放電電極への充電電圧を増減させる手法は、これに限定されるものではない。
　例えば、ＤＣ−ＡＣ昇圧回路３内にＰＷＭ制御手段３ａ（チョッパ回路やインバータ回路で構成）を設けておき、重畳電圧生成用交流としての矩形波のＯＮ／ＯＦＦデューティー比を変化させることで、多段倍電圧整流回路４への供給電力を変化させるようにしても良い。ＰＷＭ制御手段３ａにより重畳電圧生成用交流（矩形波）のＯＮデューティー時間を変更すると、多段倍電圧整流回路４に入力される矩形波の波高値は変わらないものの、ＯＮ／ＯＦＦデューティー比に応じて各キャパシタＣ１~Ｃ６の充電電圧が増減するので、多段倍電圧整流回路４から得られる直流電圧を調整することができる。
　なお、ＰＷＭ制御手段３ａは、ＤＣ−ＡＣ昇圧回路３の一機能として含ませず、ＤＣ−ＡＣ昇圧回路３の出力側に独立したチョッパ回路等として設けるようにしても構わない。斯くする場合は、重ね電流検出・比較回路８からの増減指示をＰＷＭ制御手段３ａへ供給するものとし、この指示に基づいてＰＷＭ制御手段３ａがＤＣ−ＡＣ昇圧回路３により生成された所定波高値（例えば、２００Ｖ）の矩形波に対するＯＮ／ＯＦＦデューティー比を変化させる制御を行うことで、ＰＷＭ制御手段３ａから重畳電圧生成用交流が出力されることとなる。
　以上、本発明に係る重ね放電型内燃機関用点火装置の実施形態を添付図面に基づいて説明したが、本発明は、本実施形態に限定されるものではなく、特許請求の範囲に記載の構成を変更しない範囲で、公知既存の等価な技術手段を転用することにより実施しても構わない。 Here, the operation of each part of the ignition device for the multi-discharge internal combustion engine according to the present embodiment will be described with reference to the operation waveform of FIG.
First, when a pulse having a predetermined width is input to the ignition coil 1 as an ignition signal, the switching element 1d is turned on by the rising edge of the pulse, and the primary current starts to flow through the primary coil 1a, but the switching element 1d is started by the falling edge of the ignition signal. When is turned off, no current flows through the primary coil 1a, so that a large secondary voltage is instantaneously induced in the secondary coil 1b of the ignition coil 1.
As described above, the overlap time control signal output from the overlap time control circuit 6 to the DC-AC booster circuit 3 is turned ON at the timing when the secondary voltage is induced in the secondary coil 1b (timing of the pulse fall of the ignition signal). (For example, the signal level is changed from L to H), and output of the superimposed voltage generation AC by the DC-AC booster circuit 3 is started. The DC-AC booster circuit 3 continues to output the superimposed voltage generation AC until the overlap time control signal from the overlap time control circuit 6 is turned off (the signal level changes from H to L). A high DC voltage is output from the voltage doubler rectifier circuit 4.
The DC-AC booster circuit 3 is exemplified by a DC voltage VB (for example, DC12V) of the on-vehicle battery that is output with an AC voltage of 200V. However, the DC-AC booster circuit 3 is not limited to this and is not limited to this. May be set arbitrarily.
The multistage voltage doubler rectifier circuit 4 that receives the superimposed voltage generating alternating current from the DC-AC booster circuit 3 configured as described above is a voltage doubler rectifier circuit that outputs a direct current voltage that is twice the peak value of the input alternating current. , And a DC high voltage of 1.2 kV DC, which is 6 times higher than the AC 200 V input, can be obtained.
The voltage doubler rectifier circuit used for the multistage voltage doubler rectifier circuit 4 may be a known one. In the three-stage voltage doubler rectifier circuit shown in FIG. 1, the capacitor C1 is charged by the diode D1, and the capacitor C2 is charged by the diode D2. Similarly, as a result of charging the capacitor C3, the capacitor C4, the capacitor C5, and the capacitor C6 by the diode D3, the diode D4, the diode D5, and the diode D6, the capacitor C2, the capacitor C4, and the capacitor C6 connected in series are Since each is charged to approximately twice the input peak value, a direct current of 6 times the voltage (capacitor charging voltage × 2 × number of stages) can be obtained.
That is, when a DC high voltage is acquired using the multistage voltage doubler rectifier circuit 4 as shown in FIG. 1, the withstand voltages of the diodes D1 to D6 and the capacitors C1 to C6 of each voltage doubler rectifier circuit are all for generating a superimposed voltage. Since there is no problem if it is twice or more the AC voltage value, there is no need for a large capacity like the charge / discharge capacitor of the conventional ignition device for a multi-discharge internal combustion engine, and it is possible to reduce the size and cost of parts. Note that the multistage voltage doubler rectifier circuit 4 is not limited to three stages, and may be two stages or four stages or more.
The DC high voltage of 1.2 kV obtained from the multistage voltage doubler rectifier circuit 4 as described above continues until the overlap time control signal of the overlap time control circuit 6 is turned off (the signal level changes from H to L). Is output. However, when the DC high voltage obtained from the multi-stage voltage doubler rectifier circuit 4 is superimposed on the high voltage induced in the secondary coil 1b, it must be superimposed with the same polarity as the high voltage induced in the secondary coil 1b. Therefore, the superimposed voltage on the discharge electrode becomes an inverted waveform of the output of the multistage voltage doubler rectifier circuit.
As described above, in the ignition device for a multi-discharge internal combustion engine according to the present embodiment, the DC high voltage output from the multistage voltage doubler rectifier circuit 4 is the same as the high voltage induced in the secondary coil 1b of the ignition coil 1. As shown in FIG. 2, the discharge waveform of the spark plug 2 is superimposed with the DC high voltage from the multi-stage voltage doubler rectifier circuit 4 even after a large current at the beginning of ignition flows, as shown in FIG. Thus, the discharge of the spark plug 2 continues until the overlap time controlled by the overlap time control circuit 6 elapses, and the overlap current equal to the overlap current set value continues to flow.
In addition, in the ignition apparatus for the overlap discharge type internal combustion engine according to the present embodiment, the DC-AC booster circuit 3 that outputs the superimposed voltage generating alternating current, and the multistage that receives the superimposed voltage generating alternating current and generates a direct high voltage. Since the voltage doubler rectifier circuit 4 is used, the voltage value of the superimposed voltage generation AC output from the DC-AC booster circuit 3 serving as the superimposed voltage generation operation control means is increased or decreased. The voltage output from the multi-stage voltage doubler rectifier circuit 4 as the multi-stage voltage doubler rectifier can be adjusted to be higher or lower, so that a discharge current capable of discharging with characteristics suitable for the state of the air-fuel mixture can flow. it can.
Further, since the driving time of the DC-AC booster circuit 3 as the superimposed voltage generation operation control means can be arbitrarily controlled by the overlap time control circuit 6 as the overlap time control means, the direct current generated by the multi-stage voltage doubler rectifier circuit 4 can be controlled. The stacking time of the high voltage can be lengthened, shortened, or arbitrarily changed, and the discharge current can be continued for a stacking time that allows discharge having characteristics suitable for the state of the air-fuel mixture.
In addition, if the discharge energy adjustment function by the DC-AC booster circuit 3 and the overlap time adjustment function by the overlap time control circuit 6 are used together, the discharge energy superimposed on the overlap time can be arbitrarily changed. Thus, it is possible to supply the optimal discharge time and optimal discharge energy for the above-mentioned state, and it is possible to avoid the problem that unnecessary discharge of electric power continues due to excessive supply of the discharge energy or the consumption of the electrode of the spark plug 2 is accelerated.
Further, since the multistage voltage doubler rectifier circuit 4 can be configured with small components, it can be easily housed in the same case as the ignition coil 1. Moreover, if the multistage voltage doubler rectifier circuit 4 and the high voltage diode 5 are housed in the same case as the ignition coil 1, the high voltage supply line from the multistage voltage doubler rectifier circuit 4 can be housed in the case, and the direct current There is no need to route a high voltage line, and it is not necessary to secure a wiring material or wiring space with a high breakdown voltage.
In the design of the ignition device for the multi-discharge type internal combustion engine, an AC 200 V superimposed voltage generating alternating current is supplied from the DC-AC booster circuit 3 to the multistage voltage doubler rectifier circuit 4 and output from the multistage voltage doubler rectifier circuit 4. When DC 1.2 kV is superimposed on the discharge electrode, an overlap current almost equal to the overlap current setting value should be detected, but it is the same as the overlap current setting value due to instrumental differences on the circuit, aging of parts, etc. The detection voltage may be so low or high that it cannot be considered. As described above, when the superimposed voltage generation alternating current that is the reference from the DC-AC booster circuit 3 is supplied to the multistage voltage doubler rectifier circuit 4, the overlap current detection value does not match the overlap current setting value (for example, a predetermined value). When the difference exceeding the allowable error occurs), the overlap current detection / comparison circuit 8 detects this and performs feedback control to bring the overlap current detection value closer to the overlap current setting value.
An example of this feedback control will be described in detail. As a result of the overlap current detection / comparison circuit comparing the overlap current detection value and the overlap current setting value, the absolute value of the overlap current detection value is larger than the absolute value of the overlap current setting value. If it is smaller, the overlap current detection / comparison circuit 8 outputs an output increase instruction signal to the DC-AC booster circuit 3, and the DC-AC booster circuit 3 that has received this signal outputs a predetermined specified amount (for example, 1 V). The peak value of the superimposed voltage generating AC is increased, the output voltage of the multi-stage voltage doubler rectifier circuit 4 is increased (for example, increased by about 6 V, which is 6 times the added voltage), and the superimposed voltage on the discharge electrode is increased and superimposed. Increase current. The overlap current detection / comparison circuit 8 detects and compares the increased overlap current, and if the overlap current detection value is still less than the overlap current set value, the overlap current detection / comparison circuit 8 outputs an output increase instruction signal. Output to the DC-AC booster circuit 3 to further slightly increase the peak value of the superimposed voltage generating AC. If the overlap current detection value and the overlap current setting value match, the overlap increase detection / comparison circuit 8 does not output an output increase instruction signal to the DC-AC booster circuit 3. Since the output peak value of the superimposed voltage generating AC is maintained as it is, the superimposed voltage from the multistage voltage doubler rectifier circuit 4 to the discharge electrode is also maintained as it is, and the overlap current that matches the overlap current set value is maintained.
Conversely, if the overlap current detection / comparison circuit compares the overlap current detection value with the overlap current setting value and the absolute value of the overlap current detection value is greater than the absolute value of the overlap current setting value, the overlap current detection / comparison The circuit 8 outputs an output reduction instruction signal to the DC-AC booster circuit 3, and the DC-AC booster circuit 3 that has received this signal outputs the peak value of the superimposed voltage generating AC by a predetermined amount (for example, 1 V). The output voltage of the multistage voltage doubler rectifier circuit 4 is reduced (for example, reduced by about 6 V, which is six times the added voltage), and the superimposed voltage on the discharge electrode is lowered to reduce the superimposed current. The overlap current detection / comparison circuit 8 detects and compares the reduced overlap current, and if the overlap current detection value still exceeds the overlap current set value, the overlap current detection / comparison circuit 8 instructs the output reduction. The signal is output to the DC-AC booster circuit 3 to further reduce the peak value of the superimposed voltage generating AC. If the overlap current detection value matches the overlap current setting value, the overlap reduction detection / comparison circuit 8 does not output an output reduction instruction signal to the DC-AC booster circuit 3, and therefore the DC-AC booster circuit 3 Since the output peak value of the superimposed voltage generating AC is maintained as it is, the superimposed voltage from the multistage voltage doubler rectifier circuit 4 to the discharge electrode is also maintained as it is, and the overlap current that matches the overlap current set value is maintained.
Note that the overlap current set value, which is the reference for feedback control by the overlap current detection / comparison circuit 8, can be arbitrarily set by inputting an overlap current setting signal from the outside. Since the optimum overlap current value can be set according to the characteristics of the engine to which the device is applied, the versatility of the device can be enhanced.
Further, the feedback control realized by the superimposed current detection / comparison circuit 8 and the DC-AC booster circuit 3 is not limited to the above-described method, and a known existing method may be appropriately used. For example, a correspondence table or an arithmetic expression in which the difference between the overlap current set value and the overlap current detection value and the output increase / decrease value instructed to the DC-AC booster circuit 3 to fill this difference is associated with the overlap current detection / comparison. A signal (an output increase instruction signal or an output decrease instruction signal) including an output increase / decrease amount determined from the correspondence table or the arithmetic expression is stored in the circuit 8 from the overlap current detection / comparison circuit 8 to the DC-AC booster circuit 3. The DC-AC booster circuit 3 that receives this signal changes the peak value of the superimposed voltage generating AC based on the instruction information, and increases or decreases the charging voltage from the multistage voltage doubler rectifier circuit 4 to the discharge electrode at once. The overlap current may be brought close to the set value quickly.
Further, in the above-described embodiment of the ignition device for the multi-discharge internal combustion engine, the power supplied to the multistage voltage doubler rectifier circuit 4 by changing the peak value of the superimposed voltage generating AC supplied from the DC-AC booster circuit 3. The charging voltage of each of the capacitors C1 to C6 of the multistage voltage doubler rectifier circuit 4 is increased or decreased to increase or decrease the superimposed voltage on the discharge electrode, but the method of increasing or decreasing the charging voltage to the discharge electrode is as follows: It is not limited to this.
For example, by providing PWM control means 3a (configured by a chopper circuit or an inverter circuit) in the DC-AC booster circuit 3 and changing the ON / OFF duty ratio of the rectangular wave as the superimposed voltage generating AC, a multi-stage The power supplied to the voltage doubler rectifier circuit 4 may be changed. When the ON duty time of the superimposed voltage generating alternating current (rectangular wave) is changed by the PWM control means 3a, although the peak value of the rectangular wave input to the multistage voltage doubler rectifier circuit 4 does not change, it depends on the ON / OFF duty ratio. Since the charging voltage of each of the capacitors C1 to C6 increases or decreases, the DC voltage obtained from the multistage voltage doubler rectifier circuit 4 can be adjusted.
Note that the PWM control means 3a may not be included as one function of the DC-AC booster circuit 3, but may be provided as an independent chopper circuit or the like on the output side of the DC-AC booster circuit 3. In such a case, an increase / decrease instruction from the overlap current detection / comparison circuit 8 is supplied to the PWM control means 3a, and the PWM control means 3a generates a predetermined peak value generated by the DC-AC booster circuit 3 based on this instruction. By performing control to change the ON / OFF duty ratio with respect to the rectangular wave (for example, 200 V), the superimposed voltage generation AC is output from the PWM control unit 3a.
As mentioned above, although the embodiment of the ignition device for the overlap discharge type internal combustion engine according to the present invention has been described based on the accompanying drawings, the present invention is not limited to this embodiment, and the configuration described in the claims. As long as the above is not changed, it may be carried out by diverting known equivalent technical means.

　１　　　点火コイル
　１ａ　　一次コイル
　１ｂ　　二次コイル
　１ｃ　　鉄心
　１ｄ　　スイッチング素子
　２　　　点火プラグ
　　ｇ　　放電間隙
　３　　　ＤＣ−ＡＣ昇圧回路
　３ａ　　ＰＷＭ制御手段
　４　　　多段倍電圧整流回路
　５　　　高圧ダイオード
　６　　　重ね時間制御回路
　７　　　電流検出用抵抗
　８　　　重ね電流検出・比較回路 DESCRIPTION OF SYMBOLS 1 Ignition coil 1a Primary coil 1b Secondary coil 1c Iron core 1d Switching element 2 Spark plug g Discharge gap 3 DC-AC booster circuit 3a PWM control means 4 Multistage voltage doubler rectifier circuit 5 High voltage diode 6 Overlap time control circuit 7 Current detection resistor 8 Overcurrent detection / comparison circuit

Claims (9)

　点火信号に応じて点火コイルの一次コイルの電流を遮断し、二次コイルに高電圧を誘起させると共に、該高電圧と同極性の電圧を重畳し、点火プラグの放電間隙に火花放電を起こして、燃焼室内の混合気に点火する重ね放電型内燃機関用点火装置において、
　前記点火信号に基づく二次コイルの高電圧誘起のタイミングで、所要電圧・所要周波数の重畳電圧生成用交流を出力する重畳電圧生成動作制御手段と、
　前記重畳電圧生成動作制御手段から供給される重畳電圧生成用交流の周期内で作動する倍電圧整流回路を多段に組み合わせ、入力尖頭値の段数倍の直流高電圧を出力するようにした多段倍電圧整流手段と、
　を備え、
　前記多段倍電圧整流手段から出力される直流高電圧を、前記点火コイルの二次コイルに誘起する高電圧と同極性で重畳し、点火プラグに印加することにより重ね放電を行わせるようにしたことを特徴とする重ね放電型内燃機関用点火装置。 In response to the ignition signal, the current of the primary coil of the ignition coil is cut off, a high voltage is induced in the secondary coil, a voltage having the same polarity as the high voltage is superimposed, and a spark discharge is generated in the discharge gap of the spark plug. In an ignition device for a multi-discharge internal combustion engine that ignites a mixture in a combustion chamber
Superimposed voltage generation operation control means for outputting a superimposed voltage generation alternating current of a required voltage and a required frequency at the timing of high voltage induction of the secondary coil based on the ignition signal;
A multi-stage voltage rectifier circuit that operates within the period of the superimposed voltage generation AC supplied from the superimposed voltage generation operation control means is combined in multiple stages, and a multi-stage that outputs a DC high voltage that is multiple times the input peak value. Voltage rectifying means;
With
The DC high voltage output from the multi-stage voltage doubler rectifier is superimposed with the same polarity as the high voltage induced in the secondary coil of the ignition coil and applied to the spark plug to cause overlap discharge. An ignition device for a multi-discharge internal combustion engine characterized by the above. 　点火信号に応じて点火コイルの一次コイルの電流を遮断し、二次コイルに高電圧を誘起させると共に、該高電圧と同極性の電圧を重畳し、点火プラグの放電間隙に火花放電を起こして、燃焼室内の混合気に点火する重ね放電型内燃機関用点火装置において、
　前記点火信号に基づく二次コイルの高電圧誘起のタイミングで、所要電圧・所要周波数の重畳電圧生成用交流を出力すると共に、外部よりの指示に基づいて出力する電力を増減可能な重畳電圧生成動作制御手段と、
　前記重畳電圧生成動作制御手段から供給される重畳電圧生成用交流の周期内で作動する倍電圧整流回路を多段に組み合わせ、入力電圧の段数倍の直流高電圧を出力するようにした多段倍電圧整流手段と、
　を備え、
　前記多段倍電圧整流手段から出力される直流高電圧を、前記点火コイルの二次コイルに誘起する高電圧と同極性で重畳し、点火プラグに印加することにより重ね放電を行わせ、
　前記多段倍電圧整流手段により重畳された重ね電流値を検出すると共に、予め設定された重ね電流設定値と実際に検出された重ね電流検出値とを比較し、重ね電流検出値が重ね電流設定値よりも低い場合には出力増加指示信号を前記重畳電圧生成動作制御手段へ出力し、重ね電流検出値が重ね電流設定値よりも高い場合には出力低減指示信号を前記重畳電圧生成動作制御手段へ出力するフィードバック制御手段を設け、
　前記フィードバック制御手段からの出力増加指示信号または出力低減指示信号に基づいて、前記重畳電圧生成動作制御手段が多段倍電圧整流手段へ出力する電力を調整することで、多段倍電圧整流手段から出力される直流高電圧を増減させ、重ね電流検出値を重ね電流設定値へ近づけるフィードバック制御を行うようにしたことを特徴とする重ね放電型内燃機関用点火装置。 In response to the ignition signal, the current of the primary coil of the ignition coil is cut off, a high voltage is induced in the secondary coil, a voltage having the same polarity as the high voltage is superimposed, and a spark discharge is generated in the discharge gap of the spark plug. In an ignition device for a multi-discharge internal combustion engine that ignites a mixture in a combustion chamber
Superimposed voltage generation operation capable of outputting superimposed voltage generation alternating current of required voltage and required frequency at the timing of high voltage induction of the secondary coil based on the ignition signal and increasing / decreasing the output power based on external instructions Control means;
Multi-stage voltage doubler that combines multiple voltage rectifier circuits that operate within the cycle of superimposed voltage generation AC supplied from the superimposed voltage generation operation control means to output a DC high voltage that is multiple times the input voltage. Rectifying means;
With
The DC high voltage output from the multi-stage voltage doubler rectifier is superimposed with the same polarity as the high voltage induced in the secondary coil of the ignition coil, and applied to the spark plug to cause overlap discharge,
The superimposed current value superimposed by the multi-stage voltage doubler rectifier is detected, the preset superimposed current set value is compared with the actually detected superimposed current detected value, and the superimposed current detected value is the superimposed current set value. Output increase instruction signal is output to the superimposed voltage generation operation control means, and when the overlap current detection value is higher than the overlap current set value, the output reduction instruction signal is output to the overlap voltage generation operation control means. Provide feedback control means to output,
Based on the output increase instruction signal or the output decrease instruction signal from the feedback control means, the superposed voltage generation operation control means adjusts the power output to the multi-stage voltage doubler rectifier, so that it is output from the multi-stage voltage doubler rectifier. An ignition device for a multi-discharge internal combustion engine, characterized in that feedback control is performed to increase or decrease the high DC voltage to bring the superposed current detection value closer to the superposed current set value. 　前記重畳電圧生成動作制御手段は、前記フィードバック制御手段から出力増加指示信号もしくは出力低減指示信号を受ける毎に、予め定めた規定量だけ出力を増減させるようにしたことを特徴とする請求項２に記載の重ね放電型内燃機関用点火装置。 3. The superposed voltage generation operation control means increases or decreases the output by a predetermined specified amount each time an output increase instruction signal or an output decrease instruction signal is received from the feedback control means. The ignition device for a multiple discharge internal combustion engine as described. 　前記フィードバック制御手段は、重ね電流検出値と重ね電流設定値との差に応じて出力増減量を決定すると共に、決定した出力増減量を含む出力増加指示信号もしくは出力低減指示信号を前記重畳電圧生成動作制御手段へ送信し、
　前記重畳電圧生成動作制御手段は、フィードバック制御手段からの出力増加指示信号もしくは出力低減指示信号に応じて、出力する電力を増減するようにしたことを特徴とする請求項２に記載の重ね放電型内燃機関用点火装置。 The feedback control means determines an output increase / decrease amount according to a difference between the overlap current detection value and the overlap current setting value, and generates an output increase instruction signal or an output decrease instruction signal including the determined output increase / decrease amount. Sent to the operation control means,
3. The superimposed discharge type according to claim 2, wherein the superimposed voltage generation operation control means increases or decreases the output power in accordance with an output increase instruction signal or an output decrease instruction signal from a feedback control means. Ignition device for internal combustion engine. 　前記重畳電圧生成動作制御手段は、生成する重畳電圧生成用交流の波高値を変化させることで、多段倍電圧整流手段へ出力する電力を調整するようにしたことを特徴とする請求項２~請求項４の何れか１項に記載の重ね放電型内燃機関用点火装置。 The superposition voltage generation operation control means adjusts the power output to the multistage voltage doubler rectification means by changing the peak value of the superposition voltage generation AC to be generated. Item 5. The ignition device for a multi-discharge internal combustion engine according to any one of Items 4 to 5. 　前記重畳電圧生成動作制御手段は、矩形波交流のＯＮ／ＯＦＦデューティー比を変化させるＰＷＭ制御によって、多段倍電圧整流手段へ出力する電力を調整するようにしたことを特徴とする請求項２~請求項４の何れか１項に記載の重ね放電型内燃機関用点火装置。 The superimposition voltage generation operation control means adjusts the power output to the multistage voltage doubler rectification means by PWM control that changes the ON / OFF duty ratio of the rectangular wave alternating current. Item 5. The ignition device for a multi-discharge internal combustion engine according to any one of Items 4 to 5. 　前記重畳電圧生成動作制御手段が出力する重畳電圧生成用交流の電圧値を変化させることにより、前記多段倍電圧整流手段より出力される電圧を調整できるようにしたことを特徴とする請求項１に記載の重ね放電型内燃機関用点火装置。 The voltage output from the multistage voltage doubler rectifier can be adjusted by changing the voltage value of the superimposed voltage generating AC output from the superimposed voltage generation operation control unit. The ignition device for a multiple discharge internal combustion engine as described. 　前記重畳電圧生成動作制御手段の駆動時間を任意に制御できる重ね時間制御手段を備え、前記多段倍電圧整流手段によって生成された直流高電圧の重ね時間を任意に変更できるようにしたことを特徴とする請求項１又は請求項７に記載の重ね放電型内燃機関用点火装置。 It is provided with an overlap time control means that can arbitrarily control the drive time of the superimposed voltage generation operation control means, and the overlap time of the DC high voltage generated by the multi-stage voltage doubler rectifier can be arbitrarily changed. The igniter for a multiple discharge internal combustion engine according to claim 1 or 7. 　前記多段倍電圧整流手段は、前記点火コイルと同一のケース内へ収納するようにしたことを特徴とする請求項１又は請求項７に記載の重ね放電型内燃機関用点火装置。 The igniter for a multi-discharge internal combustion engine according to claim 1 or 7, wherein the multistage voltage doubler rectifier is housed in the same case as the ignition coil.
PCT/JP2012/062880 2011-11-25 2012-05-14 Overlapping discharge-type ignition device for internal combustion engine Ceased WO2013077011A1 (en)

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