US3870918A - Ignition plug with auxiliary electrode - Google Patents

Ignition plug with auxiliary electrode Download PDF

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Publication number
US3870918A
US3870918A US394523A US39452373A US3870918A US 3870918 A US3870918 A US 3870918A US 394523 A US394523 A US 394523A US 39452373 A US39452373 A US 39452373A US 3870918 A US3870918 A US 3870918A
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US
United States
Prior art keywords
spark gap
ignition plug
electrode
auxiliary
center electrode
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
US394523A
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English (en)
Inventor
Katsuyuki Senda
Mamoru Kobashi
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.)
Toyota Motor Corp
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Toyota Motor 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 Toyota Motor Corp filed Critical Toyota Motor Corp
Application granted granted Critical
Publication of US3870918A publication Critical patent/US3870918A/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

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Classifications

    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01T—SPARK GAPS; OVERVOLTAGE ARRESTERS USING SPARK GAPS; SPARKING PLUGS; CORONA DEVICES; GENERATING IONS TO BE INTRODUCED INTO NON-ENCLOSED GASES
    • H01T13/00—Sparking plugs
    • H01T13/46—Sparking plugs having two or more spark gaps
    • H01T13/467—Sparking plugs having two or more spark gaps in parallel connection

Definitions

  • the present invention relates to an improved spark plug for use in internal combustion engines.
  • the object of the present invention is to provide an ignition plug which has asufficient ignition performance even in the case where the plug is in a carbon fouled condition, and which will not fail to ignite the gas mixture.
  • FIG. 7 is a graph showing differences in the degree of carbon fouling as well as the rate of ignition performance due to misfire for the conventional and the present ignition plugs.
  • the ignition plug comprises a center electrode 1, having a terminal 2.
  • An insulator 3 surrounds the center electrode 1, and a metal plug 4 surrounds the insulator 3 through a packing 5, plug 4 being formed with a threaded portion 6 to be screwed into a cylinder head (not shown).
  • a ground electrode 7, which is opposite the center electrode 1, is connected to the metal plug 4.
  • a primary spark gap 8 is provided between the center electrode 1 and the ground electrode 7.
  • a number of auxiliary ground electrodes 10 are provided, in the embodiment shown in FIGS. 1 and 2, on the periphery of the end surface at the threaded portion 6 on the metal plug 4.
  • the tip end of each auxiliary electrode 10 is pointed or rounded, as occasion demands.
  • the spark gap 9 for anti-fouling amounts to about 0.5 mm, which is selected to be smaller than spark gap 8.
  • auxiliary ground electrodes 10 are provided.
  • the electric field at the anti-fouling spark gap 9, between the insulator 3, on which carbon deposit 11 is formed, and the auxiliary electrode 10, is intensified, a spark is produced at the auxiliary gap, and the gas mixture is ignited.
  • a current flows at the portion 12 on the side of the packing 5 through carbon deposit 11 on the surface of the insulator to the metal plug 4
  • the voltage drop from the center electrode to the neighborhood of the anti-fouling spark gap 9 is very samll as compared with the voltage drop from the center electrode 1 to said portion 12
  • a sufficient spark discharge is provided at this anti-fouling spark gap 9.
  • the gas mixture is ignited, the carbon deposit 11 is burned with the combustion gas, and a self-cleaning of the ignition plug is obtained.
  • the discharge is provided more easily when the tip end of this auxiliary electrode 10 is pointed, and cooling effect on the flame kernel is small and it is advantageous to the ignition in this case. Also, since the auxiliary electrode discharges only under fouled conditions, less problem occurs as to the consumption of the auxiliary electrode even if the pointed tip is used. Furthermore, it is advantageous to arrange a number of auxiliary electrodes at the end of the threaded portion, because, in some cases, the carbon fouled condition on the insulator is not uniform. In this case, however, due consideration should be taken not to hinder the scavenging of burnt gas, and also not to increase the cooling of the flame kernel.
  • FIG. 5 shows an example where a teethshaped auxiliary ground electrode is provided at the tip end of the threaded portion 6 of the plug 4, and FIG. 6 shows an example where a projection 10" is formed on the side of the insulator 3, said projection serving as an auxiliary electrode.
  • FIG. 7 is a graph of the relationship between the insulation resistance between electrodes (or the degree of carbon fouling of a spark plug) and the concentration of the unburnt hydrocarbon in the exhaust gas (or the rate of misfiring); the larger the insulation resistance between the electrodes, the smaller the carbon fouling, and the larger the amount of unburnt hydrocarbon, the greater the rate of misfiring.
  • the concentration of the unburnt hydrocarbon does not change greatly even when the carbon fouling increases considerably, and there is little, if any, possibility of misfiring.
  • the ignition performance of the gas mixture will not be deteriorated; thus the amount of harmful exhaust gas, such as unburnt hydrocarbon, produced is considerably reduced. It is known that by providing an exhaust gas recirculation system or ignition time delaying device as the exhaust purifying means, the combustion temperature is lowered, and the carbon fouling condition is easily produced. In this case, however, even when carbon fouling may occur, the ignition of the gas mixture is always assured by the ignition plug of the present invention, so that overheating of the exhaust gas purifying catalyser is prevented, and the danger of vehicle fire or deterioration of the catalyser can be prevented.
  • the ignition performance to the gas mixture is excellent, and the carbon is burnt off by electric current flowing over the insulator, so that recovery from a carbon fouling condition of the ignition plug is improved remarkably. Since the auxiliary ground electrode is short, cooling is excellent and no abnormal combustion will be, produced.
  • An ignition plug comprising:
  • a mounting member surrounding at least a portion of said insulating member and adapted for mounting said ignition plug in an operating condition
  • a ground electrode coupled to said mounting memher and disposed adjacent to and spaced from an end portion of said center electrode to form a primary spark gap therewith; and an auxiliary electrode defining a secondary spark gap between the end portions of said insulating and mounting members adjacent said primary spark gap, wherein said secondary spark gap is selected to be smaller than said primary spark gap.
  • auxiliary electrode comprises a radially inwardly extending end portion of said mounting member, said secondary spark gap being defined between the tip of said radially extending end portion and said insulating member.
  • An ignition plug according to claim 2 further comprising a plurality of auxiliary electrodes defining said secondary spark gap, each of said auxiliary electrodes comprising radially inwardly extending end portions of said mounting member.
  • auxiliary electrode comprises a tooth-shaped radially inwardly extending end portion of said mounting member surrounding said insulator member and forming therewith said secondary spark gap.
  • auxiliary electrode comprises a radially inwardly extending end portion of said mounting member, said secondary spark gap being defined between the tip of said radially extending end portion and said insulating member such that a spark will occur in only one of said primary and secondary spark gaps at a given time.

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  • Spark Plugs (AREA)
US394523A 1972-12-22 1973-09-05 Ignition plug with auxiliary electrode Expired - Lifetime US3870918A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP47128262A JPS4985428A (fr) 1972-12-22 1972-12-22

Publications (1)

Publication Number Publication Date
US3870918A true US3870918A (en) 1975-03-11

Family

ID=14980482

Family Applications (1)

Application Number Title Priority Date Filing Date
US394523A Expired - Lifetime US3870918A (en) 1972-12-22 1973-09-05 Ignition plug with auxiliary electrode

Country Status (2)

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US (1) US3870918A (fr)
JP (1) JPS4985428A (fr)

Cited By (20)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0774812A1 (fr) * 1995-11-15 1997-05-21 Ngk Spark Plug Co., Ltd Bougie d'allumage à électrodes multiples
EP0774813A1 (fr) * 1995-11-16 1997-05-21 Ngk Spark Plug Co., Ltd Bougie d'allumage pour moteur à combustion interne
US5633557A (en) * 1992-09-28 1997-05-27 Lindsay; Maurice E. Anti-fouling spark plug
US5680002A (en) * 1995-02-09 1997-10-21 Ngk Spark Plug Co., Ltd. Multi-polarity type spark plug for use in an internal combustion engine
US5693999A (en) * 1995-03-16 1997-12-02 Nippondenso Co., Ltd. Multiple gap spark plug for internal combustion engine
US5818152A (en) * 1995-02-02 1998-10-06 General Motors Corporation Spark plug for an internal combustion engine
US6091185A (en) * 1997-04-15 2000-07-18 Ngk Spark Plug Co., Ltd. Lateral electrode type spark plug with geometrical relationships with ground electrode
WO2001063711A1 (fr) * 2000-02-25 2001-08-30 Robert Bosch Gmbh Bougie d'allumage
RU2176122C1 (ru) * 2000-12-21 2001-11-20 Лебедев Александр Сергеевич Свеча зажигания стримерная
US20050040749A1 (en) * 2003-08-20 2005-02-24 Lindsay Maurice E. Spark plug
US20050127809A1 (en) * 2003-08-20 2005-06-16 Lindsay Maurice E. Spark plug
US20060033411A1 (en) * 2003-08-20 2006-02-16 Lindsay Maurice E Spark plug
US20060055299A1 (en) * 2004-09-14 2006-03-16 Denso Corporation Spark plug with increased durability and carbon fouling resistance
US20060202599A1 (en) * 2005-03-08 2006-09-14 Ngk Spark Plug Co., Ltd. Spark plug
US20080093965A1 (en) * 2006-10-24 2008-04-24 Denso Corporation Spark plug designed to ensure stability of ignition of air-fuel mixture
US20090096345A1 (en) * 2007-10-16 2009-04-16 Thad Whitfield Posey Uniquely designed internal combustion engine spark plug that will produce two independent ignition sparks between the spark plug electrodes for each single electrical ignition coil discharge
WO2009059866A1 (fr) * 2007-11-09 2009-05-14 Robert Bosch Gmbh Bougie d'allumage à longue durée de vie
US20140015398A1 (en) * 2011-04-25 2014-01-16 Ngk Spark Plug Co., Ltd. Spark plug and production method therefor
WO2024167510A1 (fr) * 2020-08-07 2024-08-15 EcoPower Spark, LLC Bougie d'allumage avec électrode centrale à couplage mécanique et thermique
US12381374B2 (en) 2020-08-07 2025-08-05 EcoPower Spark, LLC Spark plug with electrode head shielding element

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US1322703A (en) * 1919-11-25 Sfark-plucf
US1425329A (en) * 1918-08-26 1922-08-08 Adolph A Mellblom Spark plug
US3725715A (en) * 1971-07-19 1973-04-03 C Krow Spark plug

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US1322703A (en) * 1919-11-25 Sfark-plucf
US1425329A (en) * 1918-08-26 1922-08-08 Adolph A Mellblom Spark plug
US3725715A (en) * 1971-07-19 1973-04-03 C Krow Spark plug

Cited By (30)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5633557A (en) * 1992-09-28 1997-05-27 Lindsay; Maurice E. Anti-fouling spark plug
US5818152A (en) * 1995-02-02 1998-10-06 General Motors Corporation Spark plug for an internal combustion engine
US5680002A (en) * 1995-02-09 1997-10-21 Ngk Spark Plug Co., Ltd. Multi-polarity type spark plug for use in an internal combustion engine
US5693999A (en) * 1995-03-16 1997-12-02 Nippondenso Co., Ltd. Multiple gap spark plug for internal combustion engine
EP0774812A1 (fr) * 1995-11-15 1997-05-21 Ngk Spark Plug Co., Ltd Bougie d'allumage à électrodes multiples
US6064143A (en) * 1995-11-15 2000-05-16 Ngk Spark Plug Co., Ltd. Multielectrode spark plug
US5929556A (en) * 1995-11-16 1999-07-27 Ngk Spark Plug Co., Ltd. Spark plug with center electrode having variable diameter portion retracted from front end on insulator
EP0774813A1 (fr) * 1995-11-16 1997-05-21 Ngk Spark Plug Co., Ltd Bougie d'allumage pour moteur à combustion interne
US6091185A (en) * 1997-04-15 2000-07-18 Ngk Spark Plug Co., Ltd. Lateral electrode type spark plug with geometrical relationships with ground electrode
WO2001063711A1 (fr) * 2000-02-25 2001-08-30 Robert Bosch Gmbh Bougie d'allumage
RU2176122C1 (ru) * 2000-12-21 2001-11-20 Лебедев Александр Сергеевич Свеча зажигания стримерная
US20050040749A1 (en) * 2003-08-20 2005-02-24 Lindsay Maurice E. Spark plug
US20050127809A1 (en) * 2003-08-20 2005-06-16 Lindsay Maurice E. Spark plug
US20060033411A1 (en) * 2003-08-20 2006-02-16 Lindsay Maurice E Spark plug
US20060055299A1 (en) * 2004-09-14 2006-03-16 Denso Corporation Spark plug with increased durability and carbon fouling resistance
US7554253B2 (en) * 2004-09-14 2009-06-30 Denso Corporation Spark plug with increased durability and carbon fouling resistance
US20060202599A1 (en) * 2005-03-08 2006-09-14 Ngk Spark Plug Co., Ltd. Spark plug
US7557496B2 (en) * 2005-03-08 2009-07-07 Ngk Spark Plug Co., Ltd. Spark plug which can prevent lateral sparking
US20080093965A1 (en) * 2006-10-24 2008-04-24 Denso Corporation Spark plug designed to ensure stability of ignition of air-fuel mixture
US7816846B2 (en) * 2006-10-24 2010-10-19 Denso Corporation Spark plug with slant peripheral surface
US7902733B2 (en) * 2007-10-16 2011-03-08 Thad Whitfield Posey Uniquely designed internal combustion engine spark plug that will produce two independent ignition sparks between the spark plug electrodes for each single electrical ignition coil discharge
US20090096345A1 (en) * 2007-10-16 2009-04-16 Thad Whitfield Posey Uniquely designed internal combustion engine spark plug that will produce two independent ignition sparks between the spark plug electrodes for each single electrical ignition coil discharge
WO2009059866A1 (fr) * 2007-11-09 2009-05-14 Robert Bosch Gmbh Bougie d'allumage à longue durée de vie
US20100320894A1 (en) * 2007-11-09 2010-12-23 Detlef Hartmann Spark plug having long service life
CN101855799B (zh) * 2007-11-09 2013-05-29 罗伯特.博世有限公司 长使用寿命的火花塞
US9608412B2 (en) 2007-11-09 2017-03-28 Robert Bosch Gmbh Spark plug having long service life
US20140015398A1 (en) * 2011-04-25 2014-01-16 Ngk Spark Plug Co., Ltd. Spark plug and production method therefor
US8981633B2 (en) * 2011-04-25 2015-03-17 Ngk Spark Plug Co., Ltd. Spark plug and production method therefor
WO2024167510A1 (fr) * 2020-08-07 2024-08-15 EcoPower Spark, LLC Bougie d'allumage avec électrode centrale à couplage mécanique et thermique
US12381374B2 (en) 2020-08-07 2025-08-05 EcoPower Spark, LLC Spark plug with electrode head shielding element

Also Published As

Publication number Publication date
JPS4985428A (fr) 1974-08-16

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