US3498281A - Small engine capacitor discharge ignition system - Google Patents

Small engine capacitor discharge ignition system Download PDF

Info

Publication number
US3498281A
US3498281A US754874A US3498281DA US3498281A US 3498281 A US3498281 A US 3498281A US 754874 A US754874 A US 754874A US 3498281D A US3498281D A US 3498281DA US 3498281 A US3498281 A US 3498281A
Authority
US
United States
Prior art keywords
capacitor
magnet
core
spark plug
firing
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.)
Expired - Lifetime
Application number
US754874A
Other languages
English (en)
Inventor
Joseph R Harmness
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.)
Briggs and Stratton Corp
Original Assignee
Briggs and Stratton Corp
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by Briggs and Stratton Corp filed Critical Briggs and Stratton Corp
Application granted granted Critical
Publication of US3498281A publication Critical patent/US3498281A/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

Links

Images

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
    • F02P1/00—Installations having electric ignition energy generated by magneto- or dynamo- electric generators without subsequent storage
    • F02P1/08—Layout of circuits
    • F02P1/086—Layout of circuits for generating sparks by discharging a capacitor into a coil circuit
    • 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

Definitions

  • the core of the step-up transformer or ignition coil is juxtaposed to the orbit of a flywheel-carriedmagnet, whereby a current is induced in the secondary that provides for continuance of plug firing after condenser discharge.
  • a separate coil connected in series with the secondary and the plug, is arranged to cooperate with the magnet in generating such current.
  • This invention pertains to solid state capacitor discharge ignition systems for reciprocating internal combustion engines, and relates more particularly to a capacitor discharge ignition system which is especially suited for small engines and which performs well under extreme cold starting conditions and when the engine has been choked excessively during cranking.
  • a capacitor discharge ignition system is one in which the discharge of a previously charged capacitor is relied upon to provide the energy for spark plug firing.
  • the capacitor is charged during a part of each engine cycle which precedes spark plug firing, and its discharge at the time when firing of the spark plug is to be effected is controlled by suitable switching means, usually an electronic switching element such as an SCR.
  • suitable switching means usually an electronic switching element such as an SCR.
  • the switch ing element is connected in series between the capacitor and the primary of a step-up transformer or ignition coil, so that the capacitor discharges into the primary when the switching element becomes conductive.
  • the secondary of the transformer or coil is of course connected with the spark plug.
  • charging of the capacitor can be effected by means of a permanent magnet that is mounted for orbital motion on the engine flywhel or on some other rotating engine part, in cooperation with a charging coil that is wound on a core mounted adjacent to the magnet orbit.
  • the magnet is carried orbitally past the core of the charging coil to thereby induce in the charging coil an by which the capacitor is charged.
  • a suitable rectifier arrangement prevents discharge of the capacitor back into the charging coil.
  • the switching element comprises an SCR or other triode
  • its triggering current can be produced by means of a triggering coil which is connected with the gate of the triode and is wound on a second core mounted adjacent to the orbit of the flywheel-carried magnet, in a position to be swept by the magnet at the time when firing of the plug is to take place, so that as the magnet moves past the second core a current is induced in the triggering coil that renders the triode conductive.
  • Another object of this invention is to provide a capacitor discharge type of ignition apparatus that is especially suitable for small engines, comprising a magnet which is carried by the engine flywheel for orbital motion in timed relation to the engine cycle, and Winding means cooperating with the magnet for generating a first current by which a capacitor is charged, a second current by which a capacitor discharging switching element is triggered, and a third current that can effect a prolongation of spark plug firing after the capacitor is discharged; and wherein the winding means for producing said third current can comprise the secondary of the step-up transformer conventionally used in such apparatus.
  • FIGURE 1 is a more or less diagrammatic view in elevation of ignition apparatus embodying the principles of this invention.
  • FIGURE 2 is a similar type of view but illustrating a modified embodiment of the invention.
  • the numeral 5 designates generally a rotating part of a reciprocating internal combustion engine upon which is mounted a permanent magnet 6 that is moved orbitally in timed relation to the engine cycle.
  • the permanent magnet is the only moving part in an ignition system of this invention, by which firing of a spark plug 7 is effected at the proper time in each engine cycle.
  • the remainder of the ignition apparatus comprises, in general, a charging coil 8, a capacitor 9 that is connected with the charging coil through rectifiers 10 and 11, a step-up transformer or ignition coil 12 having a primary winding 13 and a secondary winding 14 on a core 15, a triode 16 that is connected in series circuit with the capacitor and the primary 13, and a triggering coil 17 which is connected with the gate element of the triode.
  • the rotating part 5 can be assumed to be a crankshaft mounted flywheel, and it will be hereinafter so designated, so that the magnet 6 can be assumed to complete two orbits during each engine cycle if the flywheel is mounted on a four-cycle engine, or one orbit during each engine cycle in the case of a two-stroke engine.
  • the invention is applicable to either type of engine, and in the case of a single cylinder fourcycle engine it will be understood that one unneeded firing of the plug will occur during each engine cycle, as is often the case with simple four-cycle engines.
  • the charging coil 8 is wound on the bight portion of a.
  • U-shaped magnetically permeable core 18 that is mounted adjacent to the orbit of the magnet 6, in a location to be swept by the magnet during a time in the engine cycle prior to firing of the spark plug.
  • the magnet 6 is of the flat ceramic type. It is mounted on the flywheel perimeter with one of its poles (illustrated as the north pole) radially outermost and its opposite pole radially innermost and in contact with a broad, U-shaped magnetically permeable pole shoe 19 that has its legs projecting radially outwardly at opposite sides of the magnet, with the extremity of each leg providing (in this case) a south magnetic pole.
  • the legs of the U-shaped core 18 on which the charging coilis wound extend toward the magnet orbit and are spaced apart in the orbital direction by a distance somewhat less than that between the legs of the pole shoe 19.
  • a center tap 20 of the charging coil is connected with one terminal of the capacitor 9, while the other terminal of the capacitor is connected, through diode rectifiers 10 and 11, with the end terminals of the charging coil.
  • the charging coil end terminals are connected with like terminals of the diode rectifiers 10 and 11 so that those rectifiers provide full wave rectification of the A.C. induced in the charging coil to permit both phases of it to be utilized for charging the capacitor 9.
  • the diodes also prevent the capacitor from discharging back into the charging coil.
  • the triode 16 which is preferably an SCR, controls discharge of the capacitor 9 into the primary 13 of the step-up transformer or ignition coil 12 and is in turn controlled by the small triggering coil 17, which is wound on its own core 21.
  • the core 21 is U-shaped, and has its legs extending toward the magnet orbit to be swept by the magnet, but its legs are spaced apart by a relatively small distance so that a rapid build-up of flux occurs in the core 21 as a pair of opposite poles of the magnet structure come into alignment with its legs.
  • the core 21 is mounted in a location to be swept by the magnet during a part of the engine cycle that follows charging of the capacitor, at a time when firing of the spark plug is to occur.
  • the flux charged into the core 21 by the moving magnet 6 first builds rapidly to a peak of one polarity, then drops to zero for a short interval while the magnet itself is under both of its legs, then builds rapidly to a peak of opposite polarity, and finally drops back to zero.
  • the current induced in the triggering coil 17 by the first flux peak is utilized to fire the triode 16. Since the SCR cannot withstand a high back current, a small diode rectifier 22 is connected across the terminals of the triggering coil to short circuit current of the undesired phase that is induced therein.
  • the capacitor 9 When the SCR is rendered conductive, the capacitor 9 discharges through it into the primary 13 of the step-up transformer 12, thus inducing in the secondary 14 a voltage high enough to fire the spark plug 7.
  • a diode rectifier 24 is connected across the terminals of the primary 13 in the direction to conduct when the voltage across the primary reverses after the capacitor 9 has discharged, so as to prevent charging of the capacitor in the opposite sense and maintain a flow of current through the primary winding for some time, thereby producing a somewhat more prolonged firing of the spark plug than would be obtained without the diode 24.
  • the core 15 of the transformer 12 has legs which project toward the magnet orbit to be swept by the magnet at the time the spark plug is to fire.
  • the spacing of said legs in the orbital direction is substantially the same as that between the legs of the core 18 on which the charging coil 8 is wound.
  • Firing of the SCR 16 occurs near the beginning of the flux reversal in core 15, and for proper timing of condenser discharge the core 21 of the triggering coil can be mounted on that leg of the core 15 which is last swept by the magnet in its orbital motion, the core 21 being slightly offset from said leg in the direction counter to that of flywheel motion but being adjacent to it in the direction of the flywheel axis.
  • the current induced in the secondary is a function not only of the discharge of the capacitor through the primary 13, but also of the rapidly changing flux field charged into that core by the orbitally moving permanent magnet, and therefore the voltage across the secondary is somewhat higher than what it would be if it were due to discharge of the capacitor alone. Consequently, when the capacitor discharges there will be a brief but very high voltage spike that will assuredly initiate firing of the plug.
  • the step-up transformer 12 comprising the windings 13 and 14 and the core 15 may be somewhat ineflicient if the core 15 is made of steel laminations, due to hysteresis effects.
  • the core 15 is made of the soft ferrite class of core materials which afford good transformer action, the flux density of the core at saturation may be too low for induction of a sufficientl high voltage to sustain plug firing during the part of the cycle when flux charged into the core from the permanent magnet is relied upon to provide the energy for plug firing.
  • FIGURE 2 escapes this dilemma by reason of the provision of a separate winding 25, having its own core 115, in which is developed the magnet produced energy for the prolongation of plug firing.
  • the primary 13 and secondary 14' of the step-up transformer or ignition coil 12 are wound on a separate core 215, which can be of a material selected solely with regard to its efiiciency as a transformer core and situated in any convenient location.
  • the core 115 for the winding is of course mounted adjacent to the orbit of the magnet 6, in the same relative location as the core 15 in the FIGURE 1 embodiment, to be swept by the magnet during that portion of the engine cycle in which plug firing is to occur. That core can be selected solely on the basis of its etficiency for cooperation with the magnet 6 in generating an in the winding 25.
  • the winding 25 is connected in series with the secondary 14' and the spark plug, so that during that portion of the cycle in which discharge of the capacitor 9 occurs, the voltage across the spark plug is the sum of the voltages across the secondary 14' and across the winding 25.
  • the charging coil 8' has no center tap and has one of its terminals connected directly with a terminal of the condenser 9 by means of a conductor 29 while its other terminal is connected with the opposite condenser terminal through a diode rectifier 10'.
  • This arrangement which provides for half-wave rectification, utilizes for condenser charging only current of one phase that is induced in the charging coil, and may be very satisfactory in some cases.
  • the half-wave rectifier charging arrangement could be used in the FIG- URE 1 embodiment in place of the full-wave rectifier charging apparatus there illustrated, and vice versa.
  • FIGURE 2 corresponds to that shown in FIGURE 1.
  • this invention provides capacitor discharge ignition apparatus which is especially suitable for a single cylinder internal combustion engine and whereby greatly improved engine staring performance is obtained in extremely cold weather and when the engine has been choked excessively, by reason of the fact that the apparatus of this invention provides for spark plug firing during a substantially long portion of each cycle when liquid fuel is present in the combustion chamber.
  • Ignition apparatus for firing a spark plug of a reciprocating internal combustion engine, comprising a magnet that moves orbitally in timed relation to the engine cycle, a capacitor, means for charging the capacitor as the magnet moves through a first part of its orbit, first winding means, and switching means connected in series with the capacitor and the first winding means and arranged to be rendered conductive as the magnet moves through a second part of its orbit to provide for discharge of the capacitor through the first winding means, said ignition apparatus being characterized by:
  • Ignition apparatus for firing a spark plug of a reciprocating internal combustion engine of the type comprising a capacitor, first winding means, and a triode that is connected in series between the capacitor and the first winding means and has a gate element to which current can be applied to render the triode conductive so that'the capacitor can discharge through the first winding means, said ignition apparatus being characterized by:
  • the ignition apparatus of claim 2 further characterized by:
  • said first winding means and said second winding means respectively comprising the primary and secondary of a step-up transformer, and both being in fiux linking relation to said core.
  • the ignition apparatus of claim 2 further characterized by:
  • said first winding means comprising the primary of a step-up transformer
  • said second winding means having (1) a first portion which is inductively coupled with the first winding means to provide the secondary of the step-up transformer, and
  • Ignition apparatus for firing a spark plug of a reciprocating internal combustion engine in a predetermined portion of the engine cycle comprising a capacitor, means for charging the capacitor during a part of the engine cycle prior to that in which the spark plug is to be fired, inductance means connected with the spark plug, and switching means connected between the capacitor and the inductance means to control the time of discharge of the capacitor into the inductance means and thereby control the initiation of spark plug firing, said ignition apparatus being characterized by:
  • said current generating means comprising (A), a magnet carried by a movable part of the engine for orbital motion in timed relation to the engine cycle;
  • (C) winding means in flux linking relationship with said core means and operatively associated with the inductance means.
  • Ignition apparatus for firing a spark plug of a reciprocating internal combustion engine in a predetermined portion of the engine cycle comprising a capacitor, means for charging the capacitor during a part of the engine cycle which precedes said portion thereof in which spark plug firing occurs, inductance means connected with the spark plug, and switching means connected between the capacitor and the inductance means to control the time of discharge of the capacitor into the inductance means and thereby control the initiation of spark plug firing, said ignition apparatus being characterized by:
  • Ignition apparatus for firing a spark plug of a reciprocating internal combustion engine, comprising a magnet that moves orbitally in timed relation to the engine cycle, a capacitor, means for charging the capacitor as the magnet moves through a first part of its orbit, a step-up transformer having a core, a primary wound on the core and connectable with the capacitor through switching means rendered conductive as the magnet moves through a second part of its orbit, and a secondary connected with a spark plug, said ignition apparatus being characterized by:
  • magnetically permeable means on the core of the stepup transformer providing a pair of legs that project toward the magnet orbit, said legs being in orbitally spaced relationship and being arranged to be swept by the magnet in said second part of its orbit and to cooperate with it in producing a changing flux in the core by which a voltage is induced in the secondary that can prolong firing of the spark plug beyond discharge of the capacitor when the voltage required to maintain spark plug firing is low.

Landscapes

  • Engineering & Computer Science (AREA)
  • Chemical & Material Sciences (AREA)
  • Combustion & Propulsion (AREA)
  • Mechanical Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Physics & Mathematics (AREA)
  • Plasma & Fusion (AREA)
  • Ignition Installations For Internal Combustion Engines (AREA)
  • Permanent Magnet Type Synchronous Machine (AREA)
US754874A 1968-08-23 1968-08-23 Small engine capacitor discharge ignition system Expired - Lifetime US3498281A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
US75487468A 1968-08-23 1968-08-23

Publications (1)

Publication Number Publication Date
US3498281A true US3498281A (en) 1970-03-03

Family

ID=25036750

Family Applications (1)

Application Number Title Priority Date Filing Date
US754874A Expired - Lifetime US3498281A (en) 1968-08-23 1968-08-23 Small engine capacitor discharge ignition system

Country Status (7)

Country Link
US (1) US3498281A (de)
JP (1) JPS4814454B1 (de)
BE (1) BE733181A (de)
CH (1) CH501833A (de)
DE (1) DE1926952B2 (de)
FR (1) FR2016230A1 (de)
GB (1) GB1265677A (de)

Cited By (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3612948A (en) * 1969-10-09 1971-10-12 Brunswick Corp Electrical pulse triggered systems
US3667441A (en) * 1969-05-16 1972-06-06 Outboard Marine Corp Capacitor discharge ignition system with automatic spark advance
US3746901A (en) * 1972-02-18 1973-07-17 Bosch Gmbh Robert Magneto generator for ignition systems of internal combustion engines
US3828754A (en) * 1971-09-01 1974-08-13 Svenska Electromagneter Flywheel magneto ignition device with capacitor-thyristor ignition combined with generator
US3941111A (en) * 1973-09-10 1976-03-02 Syncro Corporation Ignition system
US4019485A (en) * 1971-12-03 1977-04-26 Aktiebolaget Svenska Electromagneter Flywheel magneto having capacitive ignition system
EP0600016A1 (de) * 1991-08-23 1994-06-08 Massachusetts Institute Of Technology Zündsystem mit dualer energiezuführung
US20210017946A1 (en) * 2017-03-30 2021-01-21 Mahle Electric Drives Japan Corporation Engine ignition method and engine ignition device

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
IT1160556B (it) * 1978-07-28 1987-03-11 Fiat Spa Impianto di accensione a scarica capacitiva alimentato a corrente trifase per motori a combustione interna destinati ad impianti fissi

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3280809A (en) * 1962-03-10 1966-10-25 Bosch Gmbh Robert Ignition arrangement for internal combustion engines
US3326199A (en) * 1964-08-10 1967-06-20 Bosch Arma Corp Magneto ignition system for internal combustion engines and the like
US3447521A (en) * 1967-06-22 1969-06-03 Phelon Co Inc Breakerless ignition system with automatic spark advance using triggering coil

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3280809A (en) * 1962-03-10 1966-10-25 Bosch Gmbh Robert Ignition arrangement for internal combustion engines
US3326199A (en) * 1964-08-10 1967-06-20 Bosch Arma Corp Magneto ignition system for internal combustion engines and the like
US3447521A (en) * 1967-06-22 1969-06-03 Phelon Co Inc Breakerless ignition system with automatic spark advance using triggering coil

Cited By (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3667441A (en) * 1969-05-16 1972-06-06 Outboard Marine Corp Capacitor discharge ignition system with automatic spark advance
US3612948A (en) * 1969-10-09 1971-10-12 Brunswick Corp Electrical pulse triggered systems
US3828754A (en) * 1971-09-01 1974-08-13 Svenska Electromagneter Flywheel magneto ignition device with capacitor-thyristor ignition combined with generator
US4019485A (en) * 1971-12-03 1977-04-26 Aktiebolaget Svenska Electromagneter Flywheel magneto having capacitive ignition system
US3746901A (en) * 1972-02-18 1973-07-17 Bosch Gmbh Robert Magneto generator for ignition systems of internal combustion engines
US3941111A (en) * 1973-09-10 1976-03-02 Syncro Corporation Ignition system
EP0600016A1 (de) * 1991-08-23 1994-06-08 Massachusetts Institute Of Technology Zündsystem mit dualer energiezuführung
EP0600016A4 (de) * 1991-08-23 1994-08-31 Massachusetts Institute Of Technology
US20210017946A1 (en) * 2017-03-30 2021-01-21 Mahle Electric Drives Japan Corporation Engine ignition method and engine ignition device
US11692502B2 (en) * 2017-03-30 2023-07-04 Mahle International Gmbh Engine ignition method and engine ignition device

Also Published As

Publication number Publication date
DE1926952A1 (de) 1970-02-26
GB1265677A (de) 1972-03-01
CH501833A (de) 1971-01-15
FR2016230A1 (de) 1970-05-08
BE733181A (de) 1969-11-03
JPS4814454B1 (de) 1973-05-08
DE1926952B2 (de) 1977-07-14

Similar Documents

Publication Publication Date Title
US3464397A (en) Ignition system for internal combustion engines and the like
US3498281A (en) Small engine capacitor discharge ignition system
US4538586A (en) Capacitive discharge ignition with long spark duration
US3545420A (en) Capacitor discharge ignition system
US3955549A (en) CD ignition system with anti-reverse feature
US4170207A (en) Ignition system for a multicylinder internal combustion engine
US3034018A (en) Transistorized breakerless ignition system
US3677253A (en) Capacitor discharge type ignition system for internal combustion engines
US3661132A (en) Ignition circuit with automatic spark advance
US3515109A (en) Solid state ignition with automatic timing advance
US3723809A (en) Magneto-dynamo-operated ingition device for multi-cylinder engines
US2980822A (en) Ignition system
US3842817A (en) Capacitive discharge ignition system
US3718125A (en) Capacitor discharge ignition system
JPS6252147B2 (de)
US3491281A (en) Blocking oscillator power supply
US3612023A (en) Ignition arrangement for internal combustion engines
US3140423A (en) Spark ignition apparatus for internal combustion engine
CA1107346A (en) Ignition system for internal combustion engines with a magneto generator
US3620200A (en) Booster circuit for ignition systems
GB2027120A (en) Breakerless flywheel magneto ignition system
US3504230A (en) Solid-state ionizing ignition system
US3720194A (en) Ignition system
US6588407B2 (en) Discharge ignition apparatus for internal combustion engine having automatic spark advance
US6799557B2 (en) Processor controlled discharge ignition with fixed firing angle at startup