US3882341A - Spark plug with inductive suppressor - Google Patents

Spark plug with inductive suppressor Download PDF

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Publication number
US3882341A
US3882341A US436079A US43607974A US3882341A US 3882341 A US3882341 A US 3882341A US 436079 A US436079 A US 436079A US 43607974 A US43607974 A US 43607974A US 3882341 A US3882341 A US 3882341A
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US
United States
Prior art keywords
suppressor
core
spark plug
wire
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
US436079A
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English (en)
Inventor
Sam J Green
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.)
Federal Mogul Ignition LLC
Original Assignee
Champion Spark Plug Co
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 Champion Spark Plug Co filed Critical Champion Spark Plug Co
Priority to US436079A priority Critical patent/US3882341A/en
Priority to ZA00747295A priority patent/ZA747295B/xx
Priority to BE152037A priority patent/BE823981A/xx
Priority to FR7500065A priority patent/FR2259457B1/fr
Priority to IT47603/75A priority patent/IT1026291B/it
Application granted granted Critical
Publication of US3882341A publication Critical patent/US3882341A/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
    • H01T13/40—Sparking plugs structurally combined with other devices
    • H01T13/41—Sparking plugs structurally combined with other devices with interference suppressing or shielding means

Definitions

  • ABSTRACT Disclosed herein is a spark plug having a wire wound inductive suppressor in its center bore for suppressing radio frequency interference.
  • the suppressor utilizes a conductive, rather than a resistive wire as in many prior art suppressors.
  • the suppressor employs a core of ferromagnetic materials rather than a ceramic or insulative core. This facilitates the attainment of high inductance values with relatively large diameter wire of comparatively few winding turns, with resistance kept at low values.
  • the inductance produced by the suppressor tends to damp out radio frequency oscillations produced by the ignition system of which the spark plug is a part.
  • the invention relates to ignition circuit radio frequency interference suppressors, and more particularly to inductive suppressors of low resistance for use in the central bore of a spark plug.
  • Radio frequency interference (RFI) suppressors either in the high voltage ignition cable or in the spark plug of an automotive ignition circuit, have been known for many years.
  • the suppressors until recently, comprised resistance elements with carbon resistors being generally used.
  • High resistance carbon resistors and other high resistance suppressors cannot be depended upon in many capacitor discharge (CD) ignition systems, which are in increasing use particularly in two-cycle engines, because the high resistance may inhibit plug firing.
  • CD capacitor discharge
  • a fast ignition pulse risetime across the spark plug gap is typical of CD systems. Accordingly, RFI suppression in CD systems is often difficult.
  • many CD systems cannot tolerate a high resistance in the secondary circuit. The most significant effect of a high resistance in these systems is a reduction in magnitude of current flow through the spark plug gap.
  • High resistance suppressors such as carbon resistors have thus been found to have the effect of limiting current flow across the spark gap as well as slowing the ignition risetime.
  • Increased inductance increases the impedance of the ignition circuit without increasing resistance.
  • the effect of the impedance is to impede or damp out high frequency oscillations MHz to 1000 MHz).
  • US. Pat. No. 3,267,325 is concerned with the generation of oscillations across a spark plug gap by means of multiple spark gaps and added capacitance and inductance.
  • a wire winding embedded in a ferritic core is shown inside the bore of a spark plug, to produce inductance.
  • the purpose of the inductor is to generate high frequency oscillations across the spark plug gap, with the addition of added capacitance and internal spark gaps. This would produce a strong RFI, so that such inductor usage directly opposes the object of the instant invention, as will be seen below.
  • the present invention is an improved RFI suppressor spark plug including a conductive wire wound suppressor of low resistance connected in series in the center electrode of the spark plug.
  • the suppressor has a ferromagnetic core to facilitate the attainment of high inductance values with relatively few wire winding turns.
  • the wire may be of comparatively large diameter.
  • an inductor coil must be insulated from a conductive core to eliminate flashover or shorting through the core.
  • a ferromagnetic or ferritic core may have sufficient insulative properties without a separate insulative shield if an appropriate binder is used in the core.
  • an RFI suppressor spark plug according to the present invention may comprise a conductive wire wound directly on a ferromagnetic core, connected in series in the center electrode assembly of a spark plug.
  • FIG. 1 is a partially sectioned elevational view of a spark plug according to the invention
  • FIG. 2 is a perspective view of an inductive suppressor incorporated in the spark plug of FIG. 1;
  • FIG. 3 is a sectional view taken along the line 33 of FIG. 2;
  • FIG. 4 is a sectional elevational view of a spark plug including a modified form of the inductive suppressor.
  • a spark plug 10 having a ceramic insulator 11 with a central bore 12 therein and a metallic outer body or shell portion 13 encasing the ceramic insulator 11 and having secured to it a ground electrode 14.
  • a center electrode assembly generally indicated by the reference number 15 extending through the length of the plug.
  • an external terminal 16 which extends outside the spark plug 10 for contact with a high voltage ignition cable.
  • a wire wound RFI inductive suppressor 17 is included within the center electrode assembly 15 extending through the length of the plug.
  • the suppressor 17 is engaged either above or below (as shown) by a spring 18 which makes electrical contact with the suppressor l7 and as sures the maintanence of good contact or electrical continuity in the center electrode assembly 15 during thermal expansion and contraction of the spark plug 10. Also in contact with the spring 18 is a lower electrode portion 19 which extends to and outside of the lower end or nose of the ceramic insulator 11 to define a spark gap 20 with the ground electrode 14.
  • the suppressor 17 includes terminal caps 21, each being in electrical contact with an end of a wound wire 22.
  • the wire winding 22 is a core 23, the composition of which includes ferromagnetic materials.
  • An insulation sheath 24 may be provided around the core 23 to insulate the wire winding 22 from the core 23, thereby preventing flashover along the core 23.
  • the terminal caps 21 may likewise be insulated from the core 23.
  • the ends 25 of the wire 22 are secured in electrical contact with the respective terminal caps 21 by soldering, welding, or any other suitable electrical connection.
  • the winding 22 is preferably of a conductive wire 1 such as copper. Its size is preferably about 40 gauge or larger.
  • the insulation sheath 24 may be of any suitable material and may comprise a total continuous enclosure of the ferromagnetic core 23 to provide the required insulation between the core 23 and the terminal caps 21 as well as between the core 23 and the wire winding 22.
  • the composition of the ferromagnetic core 23 may be such that the need for an insulation sheath 24 is obviated.
  • Such a composition would include a suitable binder material mixed with the ferromagnetic particles before pressing to provide the needed insulative quality.
  • the binding material may, for example, be a solution of polyvinyl alcohol, a phenol formaldehyde resin, polystyrene, or a glass.
  • the use of ferromagnetic materials in the core 23 gives the inductor l7 sufficient flux to facilitate the attainment of high inductance values with comparatively few turns of wire winding.
  • the relatively large diameter wire discussed above is suitable, and this highinductance suppressor may be made compact enough to fit in the small space afforded in the central bore 12 of the spark plug, such as the spark plug of FIG. 1.
  • an inductive suppressor 31 may be constructed and assembled within a spark plug 32 as shown in FIG. 4.
  • the wire winding of the suppressor 31 may comprise a coil of relatively heavy wire 33, with coils 34 and 35 extending beyond both ends of a core 36.
  • the ferromagnetic core 36 may be assembled within the wound coil 33 or cast in situ therein.
  • the wire winding 33 would act as a coil spring of greater length than the core 36, engaging the lower electrode portion 19 and the external terminal 16, and the suppressor 31 would also serve as a spring. Assembly and material costs would be thereby reduced, decreasing the cost of producing the spark plug.
  • the winding was approximately 293 turns of 0.00157 diameter copper wire.
  • the coil had a length of 0.450 inches between terminal caps and a diameter of 0.1 1 1V inches.
  • the ceramic core suppressor had a known inductance and resistance of 39 microhenries and 40 ohms, respectively.
  • p... is the effective a-c permeability of the core and air gap (CGS units), and
  • 1,. is the length of the core in inches.
  • a ferromagnetic core according to this invention was prepared and tested in a simpler inductive suppressor. Using the above equation, its permeability was found to be 44.8. Using this permeability figure, the inductance of a suppressor similar to that above but having the tested ferromagnetic core was calculated, again using the above equation. The calculation indicated an inductance of 2750 microhenries for the same 293 turns of wire, compared with the above inductance figure of 39 microhenries without the ferromagnetic core.
  • Permeability figures for ferromagnetic cores are known in the inductor art to vary from about 16 to about 4000. From the above equation it can be seen that if a core were used having a permeability of 4000, the inductance of the example inductive suppressor would be increased nearly one hundred fold. Regardless of the core used, the coils resistance would remain at about 40 ohms.
  • inductance may vary anywhere from about 40 or 50 microhenries upward.
  • Ferromagnetic core inductive suppressors according to the invention having inductance of 160 microhenries and a resistance of about 4 ohms have been prepared. Suppressors of well over 200 microhenries, with little difference in resistance also may be prepared for use in a spark plug.
  • a spark plug having a ceramic insulator with a central bore therein, a center electrode assembly within said bore, and a wire wound radio interference inductive suppressor within such center electrode assembly, said suppressor comprising a core of ferromagnetic materials and a conductive wire wound around said core and connected in series in such center electrode assembly.
  • wound wire defines a coil spring extending longitudinally within such center electrode assembly, said spring being of greater length than said core.

Landscapes

  • Chemical & Material Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Combustion & Propulsion (AREA)
  • Spark Plugs (AREA)
  • Ignition Installations For Internal Combustion Engines (AREA)
US436079A 1974-01-24 1974-01-24 Spark plug with inductive suppressor Expired - Lifetime US3882341A (en)

Priority Applications (5)

Application Number Priority Date Filing Date Title
US436079A US3882341A (en) 1974-01-24 1974-01-24 Spark plug with inductive suppressor
ZA00747295A ZA747295B (en) 1974-01-24 1974-11-13 Spark plug with inductive suppressor
BE152037A BE823981A (fr) 1974-01-24 1974-12-30 Bougie d'allumage a dispositif anti-parasite inductif
FR7500065A FR2259457B1 (fi) 1974-01-24 1975-01-02
IT47603/75A IT1026291B (it) 1974-01-24 1975-01-09 Perfezionamento nelle can ele di accensione per motori a scoppio munite di soppressore per interferenze radio

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
US436079A US3882341A (en) 1974-01-24 1974-01-24 Spark plug with inductive suppressor

Publications (1)

Publication Number Publication Date
US3882341A true US3882341A (en) 1975-05-06

Family

ID=23731027

Family Applications (1)

Application Number Title Priority Date Filing Date
US436079A Expired - Lifetime US3882341A (en) 1974-01-24 1974-01-24 Spark plug with inductive suppressor

Country Status (5)

Country Link
US (1) US3882341A (fi)
BE (1) BE823981A (fi)
FR (1) FR2259457B1 (fi)
IT (1) IT1026291B (fi)
ZA (1) ZA747295B (fi)

Cited By (16)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4224554A (en) * 1978-05-20 1980-09-23 Ngk Spark Plug Co., Ltd. Spark plug having a low noise level
US5463267A (en) * 1993-07-06 1995-10-31 Caterpillar Inc. Spark plug with automatically adjustable gap
DE10004424A1 (de) * 2000-02-02 2001-08-09 Beru Ag Zündkerze
US6427673B2 (en) 2000-02-04 2002-08-06 Visteon Global Technologies, Inc. Ignition coil assembly
US6559578B1 (en) * 1998-07-24 2003-05-06 Robert Bosch Gmbh Spark plug for an internal combustion engine
US6604736B1 (en) 2002-02-07 2003-08-12 Barnes Group Inc. Spring assembly with captured core
US20060089024A1 (en) * 2004-10-22 2006-04-27 Markus Kraus Spark plug connector
US20070293064A1 (en) * 2006-06-16 2007-12-20 Dennis Steinhardt Spark plug boot
US20090050123A1 (en) * 2005-06-23 2009-02-26 Xavier Jaffrezic Spark plug for an internal combustion engine
US20090091232A1 (en) * 2005-11-14 2009-04-09 Renault S.A.S. Sparkplug for an internal combustion engine
DE102010055570B3 (de) * 2010-12-21 2012-03-15 Borgwarner Beru Systems Gmbh Korona-Zündeinrichtung
DE102013203002B3 (de) * 2013-02-25 2014-07-10 Continental Automotive Gmbh Zündvorrichtung
EP2950406A1 (en) * 2014-05-29 2015-12-02 NGK Spark Plug Co., Ltd. Spark plug
EP3089290A4 (en) * 2013-12-25 2017-10-11 NGK Spark Plug Co., Ltd. Spark plug
US10270228B2 (en) * 2017-08-22 2019-04-23 Ngk Spark Plug Co., Ltd. Spark plug
US11742636B1 (en) * 2022-10-18 2023-08-29 Ford Global Technologies, Llc Spark plug for boosted engine

Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2597978A (en) * 1948-07-16 1952-05-27 Sylvania Electric Prod Spark plug
US2896120A (en) * 1955-12-23 1959-07-21 Bosch Gmbh Robert Ignition noise suppressor
US3191133A (en) * 1961-04-25 1965-06-22 Texsier Leon Interference suppressor for internal combustion engines
US3267325A (en) * 1962-12-06 1966-08-16 Gen Motors Corp Combined spark plugs and oscillatory circuit
US3504228A (en) * 1967-07-31 1970-03-31 Champion Spark Plug Co Spark plug with an internal resistor
US3771006A (en) * 1972-02-14 1973-11-06 N Berry Ignition circuit radiation suppression structure

Patent Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2597978A (en) * 1948-07-16 1952-05-27 Sylvania Electric Prod Spark plug
US2896120A (en) * 1955-12-23 1959-07-21 Bosch Gmbh Robert Ignition noise suppressor
US3191133A (en) * 1961-04-25 1965-06-22 Texsier Leon Interference suppressor for internal combustion engines
US3267325A (en) * 1962-12-06 1966-08-16 Gen Motors Corp Combined spark plugs and oscillatory circuit
US3504228A (en) * 1967-07-31 1970-03-31 Champion Spark Plug Co Spark plug with an internal resistor
US3771006A (en) * 1972-02-14 1973-11-06 N Berry Ignition circuit radiation suppression structure

Cited By (29)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4224554A (en) * 1978-05-20 1980-09-23 Ngk Spark Plug Co., Ltd. Spark plug having a low noise level
US5463267A (en) * 1993-07-06 1995-10-31 Caterpillar Inc. Spark plug with automatically adjustable gap
US6559578B1 (en) * 1998-07-24 2003-05-06 Robert Bosch Gmbh Spark plug for an internal combustion engine
DE10004424A1 (de) * 2000-02-02 2001-08-09 Beru Ag Zündkerze
DE10004424C2 (de) * 2000-02-02 2003-10-23 Beru Ag Zündkerze
US6427673B2 (en) 2000-02-04 2002-08-06 Visteon Global Technologies, Inc. Ignition coil assembly
US6604736B1 (en) 2002-02-07 2003-08-12 Barnes Group Inc. Spring assembly with captured core
EP1335146A1 (en) 2002-02-07 2003-08-13 Barnes Group, Inc. Spring assembly with captured core
US20060089024A1 (en) * 2004-10-22 2006-04-27 Markus Kraus Spark plug connector
US7252078B2 (en) * 2004-10-22 2007-08-07 Ge Jenbacher Gmbh & Co Ohg Spark plug connector
US7652414B2 (en) * 2005-06-23 2010-01-26 Renault S.A.S. Spark plug having an inductive upper portion incorporating a coil wound around an elastically deformable core element
US20090050123A1 (en) * 2005-06-23 2009-02-26 Xavier Jaffrezic Spark plug for an internal combustion engine
US20090091232A1 (en) * 2005-11-14 2009-04-09 Renault S.A.S. Sparkplug for an internal combustion engine
US7915795B2 (en) * 2005-11-14 2011-03-29 Renault S.A.S. Sparkplug for an internal combustion engine
US7455537B2 (en) 2006-06-16 2008-11-25 Briggs & Stratton Corporation Spark plug boot
US20070293064A1 (en) * 2006-06-16 2007-12-20 Dennis Steinhardt Spark plug boot
DE102010055570B3 (de) * 2010-12-21 2012-03-15 Borgwarner Beru Systems Gmbh Korona-Zündeinrichtung
US8767372B2 (en) 2010-12-21 2014-07-01 Borgwarner Beru Systems Gmbh Corona ignition device
US9147999B2 (en) 2013-02-25 2015-09-29 Continental Automotive Gmbh Ignition apparatus
DE102013203002B3 (de) * 2013-02-25 2014-07-10 Continental Automotive Gmbh Zündvorrichtung
EP3089290A4 (en) * 2013-12-25 2017-10-11 NGK Spark Plug Co., Ltd. Spark plug
EP2950406A1 (en) * 2014-05-29 2015-12-02 NGK Spark Plug Co., Ltd. Spark plug
JP2015225793A (ja) * 2014-05-29 2015-12-14 日本特殊陶業株式会社 スパークプラグ
CN105281203A (zh) * 2014-05-29 2016-01-27 日本特殊陶业株式会社 火花塞
US9281662B2 (en) 2014-05-29 2016-03-08 Ngk Spark Plug Co., Ltd. Spark plug
CN105281203B (zh) * 2014-05-29 2017-05-03 日本特殊陶业株式会社 火花塞
US10270228B2 (en) * 2017-08-22 2019-04-23 Ngk Spark Plug Co., Ltd. Spark plug
US11742636B1 (en) * 2022-10-18 2023-08-29 Ford Global Technologies, Llc Spark plug for boosted engine
US11942764B1 (en) 2022-10-18 2024-03-26 Ford Global Technologies, Llc Spark plug for boosted engine

Also Published As

Publication number Publication date
FR2259457A1 (fi) 1975-08-22
ZA747295B (en) 1975-11-26
IT1026291B (it) 1978-09-20
FR2259457B1 (fi) 1980-11-07
BE823981A (fr) 1975-04-16

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