EP0131905A2 - Contactless magnet ignition system - Google Patents
Contactless magnet ignition system Download PDFInfo
- Publication number
- EP0131905A2 EP0131905A2 EP84108142A EP84108142A EP0131905A2 EP 0131905 A2 EP0131905 A2 EP 0131905A2 EP 84108142 A EP84108142 A EP 84108142A EP 84108142 A EP84108142 A EP 84108142A EP 0131905 A2 EP0131905 A2 EP 0131905A2
- Authority
- EP
- European Patent Office
- Prior art keywords
- core
- winding
- primary winding
- ignition system
- carrying
- 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.)
- Withdrawn
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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
- F02P1/00—Installations having electric ignition energy generated by magneto- or dynamo- electric generators without subsequent storage
- F02P1/02—Installations having electric ignition energy generated by magneto- or dynamo- electric generators without subsequent storage the generator rotor being characterised by forming part of the engine flywheel
-
- 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
- F02P1/083—Layout of circuits for generating sparks by opening or closing a coil circuit
Definitions
- the present invention relates to a contactless magnetic- induction ignition system for internal combustion engines.
- Magnet ignition systems are generally based on the principle of the generation of a voltage in a conductor subjected to a variable magnetic flux. More particularly, a sudden decrease of the magnetic flux in a core carrying an electric conductor is effective to induce a high voltage which may be applied to a spark plug, resulting in the generation of a spark, and thus in ignition of the combustion mixture.
- Known contactless magnet ignition systems for internal combustion engines normally employ electronic circuits for interrupting the current flow in the primary winding so as to induce in the secondary winding a high voltage effective to generate a spark at the proper instant during the operating cycle of the engine.
- This auxiliary coil is normally mounted together with the ignition coil proper on a single magnetic core, so that the voltage generated in the auxiliary winding is induced by a part of the magnetic flux which is thus unable to contribute to the current flow in the short-circuited primary winding.
- this object is attained in a contactless magnet ignition system comprising a first core of U-shaped cross-sectional configuration carrying a primary winding on its central portion defined between the legs of said U-shape.
- a second core carries a control winding, while a rotor carrying at least one permanent magnet is adapted to generate a variable flux in said cores for inducing respective voltages at the terminals of the windings.
- Control means are controleld by the voltage induced in said control winding for interrupting the current flow in a closing circuit of said primary winding.
- This ignition system is essentially characterized in that said second core is disposed outside of said primary winding with its axis substantially perpendicular to the main axis of said first core and spaced therefrom within the space enclosed between said legs.
- the ignition system comprises a rotatory component having two magnetic poles and formed of a rotor 3 proper made of a ferromagnetic material (constituting one polarity) and carrying a permanent magnet 4 provided with a pole shoe member 5 mace of a ferromagnetic material (constituting the other polarity).
- the rotatory component shown in fig. 1 is adapted to rotate in the clockwise direction and is driven by the shaft of an internal combustion engine.
- the stationary component of the ignition system comprises a first magnetic core 6 of U-shaped cross-sectional configuration includign a central portion 7 defined between two legs 8 extending towards rotor 3..
- the ignition coil of the system comprising a primary winding 10 and a secondary winding 11 connected to the electrodes of a spark plug 12 (fig. 2).
- the ignition system comprises an electronic circuit 13 for short-circuiting primary winding 10, circuit 13 being of a per se known type and essentially including two Darlington-connected transistors 14, 15, resistors 16, 17 a polarization diode 18.
- the collector of transistor 19 is connected to the base of transistor 14, while its base is connected via a resistor 21 and a rectifier diode 22 to a terminal of a control winding 23.
- the other terminal of control wincing 23 is grounded, and the base of transistor 19 is also connected to ground through a capacitor 24.
- capacitor 24 and resistor 21 together form a time constant circuit having a double function as will be explained.
- control winding 23 is disposed on a second core 9 separate from first core 6 and disposed outside of primary winding 10.
- second core 9 is disposed with its axis substantially perpendicular to the main axis of first core 6 and at a substantial distance therefrom within the space defined between legs 8.
- Second core 9 and the associated control winding 23 are preferably mounted on a base plate (not shown) carrying the main electronic components of the circuit shown in fig. 2.
- second core 9 and control winding 23 are disposed at a slightly offset location with respect to first core 6 and ignition coil 10, 11 (taking into account the direction of rotation of rotor 3).
- a voltage pulse is generated in ccntrol winding 23 when the current flowing through primary winding 10 is substantially at its maximum value.
- the operation of the circuit shown in fig. 2 is per se known.
- the electronic circuit 13 is normally made conductive by the voltage generated in primary winding 10, so that the latter is practically short-circuited.
- rotor 3. 4, 5 acts to induce in control winding 23 a voltage pulse which is applied through diode 22 and time constant circuit 21, 24 to transistor 19 to render the latter conductive.
- RC circuit 21, 24 By suitably dimensioning RC circuit 21, 24 it is possible to adjust (in combination with the physical location of control winding 23) the blocking instant of electronic circuit 13 and thus the instant at which the spark is dis- charegd across spark plug 12.
- RC circuit 21, 24 controls the switching speed of transistor 19 so as to limit the value of the overvoltage at the terminals of the electronoc circuit 13 as the latter is blocked. In this manner it is avoided that the overvoltage at the terminals cf electronic circuit 13 exceeds the breakdown voltage, whereby the reliability of the entire ignition system is improved.
- the particular positioning of cores 6 and 9 and the respective windigns 10, 11 and 23 relative to one another minimizes the possibility of interference signals being induced in control winding 23 (particularly on short-circuiting primary winding 10).
- the ignition system functions in a highly accurate manner so as to attain the above stated object of the invention.
Landscapes
- Engineering & Computer Science (AREA)
- Chemical & Material Sciences (AREA)
- Combustion & Propulsion (AREA)
- Mechanical Engineering (AREA)
- General Engineering & Computer Science (AREA)
- Ignition Installations For Internal Combustion Engines (AREA)
Abstract
Description
- The present invention relates to a contactless magnetic- induction ignition system for internal combustion engines.
- Magnet ignition systems are generally based on the principle of the generation of a voltage in a conductor subjected to a variable magnetic flux. More particularly, a sudden decrease of the magnetic flux in a core carrying an electric conductor is effective to induce a high voltage which may be applied to a spark plug, resulting in the generation of a spark, and thus in ignition of the combustion mixture.
- Known contactless magnet ignition systems for internal combustion engines normally employ electronic circuits for interrupting the current flow in the primary winding so as to induce in the secondary winding a high voltage effective to generate a spark at the proper instant during the operating cycle of the engine.
- For controlling the timing of this interruption it is known to employ an auxiliary coil adapted to control the electronic circuit.
- This auxiliary coil is normally mounted together with the ignition coil proper on a single magnetic core, so that the voltage generated in the auxiliary winding is induced by a part of the magnetic flux which is thus unable to contribute to the current flow in the short-circuited primary winding.
- The performance of these nagnet ignition systems are unsatisfactory, particularly due to the fact that the ignition spark is unstable and of irregular strength.
- These shortcomings may be minimized by mounting the primary and auxiliary windings on separate cores, as described for example in British Patent 1,602,?29. In particular, the auxiliary winding and the respective core are disposed closely adjacent the core of the primary winding interiorly of the latter.
- This solution is not either fully satisfactory because, due to the relative positioning of the various components, the short-circuiting of the primary winding is effective to induce disturbances in the auxiliary winding which alter the operation of the entire ignition system, and paticularly interfere with the synchronism of the ignition spark.
- It is an object of the present invention to provide a contactless magnet ignition system capable of ensuring reliable, regular and accurate operation.
- According to the invention, this object is attained in a contactless magnet ignition system comprising a first core of U-shaped cross-sectional configuration carrying a primary winding on its central portion defined between the legs of said U-shape.
- A second core carries a control winding, while a rotor carrying at least one permanent magnet is adapted to generate a variable flux in said cores for inducing respective voltages at the terminals of the windings. Control means are controleld by the voltage induced in said control winding for interrupting the current flow in a closing circuit of said primary winding.
- This ignition system is essentially characterized in that said second core is disposed outside of said primary winding with its axis substantially perpendicular to the main axis of said first core and spaced therefrom within the space enclosed between said legs.
- The characteristics and advantages of the invention will become more clearly evident from the following description, given by way of a non-limiting example with referecne to the accompanying drawings, wherein:
- fig. 1 shows a diagrammatic cross-sectional view of the main parts of an ignition system according to the invention, and
- fig. 2 shows the electronic circuit of the ignition system of fig. 1 in a preferred embodiment of the invention.
- With reference to fig. 1, the ignition system comprises a rotatory component having two magnetic poles and formed of a
rotor 3 proper made of a ferromagnetic material (constituting one polarity) and carrying a permanent magnet 4 provided with apole shoe member 5 mace of a ferromagnetic material (constituting the other polarity). - The rotatory component shown in fig. 1 is adapted to rotate in the clockwise direction and is driven by the shaft of an internal combustion engine.
- The stationary component of the ignition system comprises a first
magnetic core 6 of U-shaped cross-sectional configuration includign a central portion 7 defined between twolegs 8 extending towardsrotor 3.. - Disposed on central portion 7 of
core 6 is the ignition coil of the system comprising aprimary winding 10 and a secondary winding 11 connected to the electrodes of a spark plug 12 (fig. 2). - With particular reference to fig. 2, the ignition system comprises an electronic circuit 13 for short-circuiting
primary winding 10, circuit 13 being of a per se known type and essentially including two Darlington-connectedtransistors 14, 15,resistors 16, 17 a polarization diode 18. - Additionally connecte'd in parallel to
primary winding 10 is atransistor 19 in series with apolarization resistor 20. - The collector of
transistor 19 is connected to the base of transistor 14, while its base is connected via aresistor 21 and arectifier diode 22 to a terminal of a control winding 23. The other terminal ofcontrol wincing 23 is grounded, and the base oftransistor 19 is also connected to ground through acapacitor 24. According to one aspect of the invention,capacitor 24 andresistor 21 together form a time constant circuit having a double function as will be explained. - According to another aspect of the invention, control winding 23 is disposed on a second core 9 separate from
first core 6 and disposed outside ofprimary winding 10. - As particularly shown in fig. 1, second core 9 is disposed with its axis substantially perpendicular to the main axis of
first core 6 and at a substantial distance therefrom within the space defined betweenlegs 8. Second core 9 and the associatedcontrol winding 23 are preferably mounted on a base plate (not shown) carrying the main electronic components of the circuit shown in fig. 2. - In a per se known manner, second core 9 and
control winding 23 are disposed at a slightly offset location with respect tofirst core 6 andignition coil 10, 11 (taking into account the direction of rotation of rotor 3). As a result, a voltage pulse is generated in ccntrol winding 23 when the current flowing throughprimary winding 10 is substantially at its maximum value. The operation of the circuit shown in fig. 2 is per se known. The electronic circuit 13 is normally made conductive by the voltage generated inprimary winding 10, so that the latter is practically short-circuited. As the current flowing throughprimary winding 10 is substantially at its maximum value,rotor 3. 4, 5 acts to induce in control winding 23 a voltage pulse which is applied throughdiode 22 and timeconstant circuit transistor 19 to render the latter conductive. As a result, electronic circuit 13 is abruptly brought to the non-conducting state, causing an overvoltage to appear at the terminals ofprimary winding 10, such cvervoltage being transmitted to secondary winding 11 for causing an ignition spark to be generated across the electrodes ofspark plug 12. - By suitably dimensioning
RC circuit spark plug 12. - In addition,
RC circuit transistor 19 so as to limit the value of the overvoltage at the terminals of the electronoc circuit 13 as the latter is blocked. In this manner it is avoided that the overvoltage at the terminals cf electronic circuit 13 exceeds the breakdown voltage, whereby the reliability of the entire ignition system is improved. - In any case, the particular positioning of
cores 6 and 9 and therespective windigns - The described ignition system may of course be modified in various manners within the scope of the characteristics set forth in the appended claims.
Claims (2)
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
IT45719/83A IT1195596B (en) | 1983-07-15 | 1983-07-15 | MAGNETIC IGNITION SYSTEM WITHOUT CONTACTS |
IT4571983 | 1983-07-15 |
Publications (2)
Publication Number | Publication Date |
---|---|
EP0131905A2 true EP0131905A2 (en) | 1985-01-23 |
EP0131905A3 EP0131905A3 (en) | 1986-02-26 |
Family
ID=11257654
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
EP84108142A Withdrawn EP0131905A3 (en) | 1983-07-15 | 1984-07-11 | Contactless magnet ignition system |
Country Status (3)
Country | Link |
---|---|
EP (1) | EP0131905A3 (en) |
ES (1) | ES533388A0 (en) |
IT (1) | IT1195596B (en) |
Cited By (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
WO1991001446A1 (en) * | 1989-07-25 | 1991-02-07 | Idm S.R.L. | Inductive discharge ignition system for internal combustion engines |
FR2713719A1 (en) * | 1993-12-09 | 1995-06-16 | Stihl Andreas | Magnetic ignition system for a machine with internal combustion engine, especially for motorized chain saw. |
EP0741445A2 (en) * | 1995-05-02 | 1996-11-06 | Oppama Industry Co., Ltd. | A magneto electric generator rotor and an implement for removing this rotor |
Citations (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US4090488A (en) * | 1972-12-30 | 1978-05-23 | Iida Denki Kogyo K.K. | Ignition circuit for the internal combustion engine and premature ignition prevention method in the ignition device |
GB1602329A (en) * | 1977-04-25 | 1981-11-11 | Mcculloch Corp | Breakerless magneto device |
US4336785A (en) * | 1980-04-28 | 1982-06-29 | Eltra Corporation | Magneto ignition with field-responsive biasing |
-
1983
- 1983-07-15 IT IT45719/83A patent/IT1195596B/en active
-
1984
- 1984-06-13 ES ES533388A patent/ES533388A0/en active Granted
- 1984-07-11 EP EP84108142A patent/EP0131905A3/en not_active Withdrawn
Patent Citations (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US4090488A (en) * | 1972-12-30 | 1978-05-23 | Iida Denki Kogyo K.K. | Ignition circuit for the internal combustion engine and premature ignition prevention method in the ignition device |
GB1602329A (en) * | 1977-04-25 | 1981-11-11 | Mcculloch Corp | Breakerless magneto device |
US4336785A (en) * | 1980-04-28 | 1982-06-29 | Eltra Corporation | Magneto ignition with field-responsive biasing |
Cited By (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
WO1991001446A1 (en) * | 1989-07-25 | 1991-02-07 | Idm S.R.L. | Inductive discharge ignition system for internal combustion engines |
US5265573A (en) * | 1989-07-25 | 1993-11-30 | I D M S.R.L. | Inductive discharge ignition system for internal combustion engines |
FR2713719A1 (en) * | 1993-12-09 | 1995-06-16 | Stihl Andreas | Magnetic ignition system for a machine with internal combustion engine, especially for motorized chain saw. |
EP0741445A2 (en) * | 1995-05-02 | 1996-11-06 | Oppama Industry Co., Ltd. | A magneto electric generator rotor and an implement for removing this rotor |
EP0741445A3 (en) * | 1995-05-02 | 1998-07-29 | Oppama Industry Co., Ltd. | A magneto electric generator rotor and an implement for removing this rotor |
Also Published As
Publication number | Publication date |
---|---|
IT8345719A0 (en) | 1983-07-15 |
IT1195596B (en) | 1988-10-19 |
ES8504341A1 (en) | 1985-04-01 |
ES533388A0 (en) | 1985-04-01 |
IT8345719A1 (en) | 1985-01-15 |
EP0131905A3 (en) | 1986-02-26 |
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Legal Events
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PUAI | Public reference made under article 153(3) epc to a published international application that has entered the european phase |
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AK | Designated contracting states |
Designated state(s): AT BE CH DE FR GB IT LI LU NL SE |
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PUAL | Search report despatched |
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RAP1 | Party data changed (applicant data changed or rights of an application transferred) |
Owner name: DUCATI ELETTROTECNICA SPA |
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AK | Designated contracting states |
Designated state(s): AT BE CH DE FR GB IT LI LU NL SE |
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RAP1 | Party data changed (applicant data changed or rights of an application transferred) |
Owner name: DUCATI ENERGIA S.P.A. |
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STAA | Information on the status of an ep patent application or granted ep patent |
Free format text: STATUS: THE APPLICATION IS DEEMED TO BE WITHDRAWN |
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18D | Application deemed to be withdrawn |
Effective date: 19861027 |
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RIN1 | Information on inventor provided before grant (corrected) |
Inventor name: SEVINI, PAOLO Inventor name: PIOMBINI, VINCENZO Inventor name: MARINO, PAOLO |