US3903453A - Spark plug incorporating a resistor for providing a low noise level - Google Patents

Spark plug incorporating a resistor for providing a low noise level Download PDF

Info

Publication number
US3903453A
US3903453A US509217A US50921774A US3903453A US 3903453 A US3903453 A US 3903453A US 509217 A US509217 A US 509217A US 50921774 A US50921774 A US 50921774A US 3903453 A US3903453 A US 3903453A
Authority
US
United States
Prior art keywords
resistor
spark plug
glass
aggregate
insulator
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
US509217A
Other languages
English (en)
Inventor
Kanemitsu Nishio
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.)
Niterra Co Ltd
Original Assignee
NGK Spark Plug Co Ltd
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 NGK Spark Plug Co Ltd filed Critical NGK Spark Plug Co Ltd
Application granted granted Critical
Publication of US3903453A publication Critical patent/US3903453A/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

Links

Images

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
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04B—TRANSMISSION
    • H04B15/00—Suppression or limitation of noise or interference
    • H04B15/02—Reducing interference from electric apparatus by means located at or near the interfering apparatus
    • H04B15/025—Reducing interference from ignition apparatus of fuel engines

Definitions

  • a spark plug incorporating a resistor comprises a ee- [22] Ffled' sept' 1974 ramic insulator, a metal shell for housing the insulator, an outer electrode connected to the shell and a center electrode opposed to the outer electrode and ex- 21 Appl. No.: 509,217
  • center electrode being composed of a discharge electrode portion, a conductive glass positioned at one end of the resistor, an auxiliary sealing resistor positioned at the other end of the resistor and a resistor.
  • the conductive glass, the carbonaceous resistor and the auxiliary resistor are placed between the discharge and the terminal electrode portions so as References C'ted to elongate an effective resistance portion of the resis- UNITED STATES PATENTS tor.
  • the present invention relates to a spark plug incorporating a resistor for providing a low noise level.
  • a spark plug comprising conductive glasses and a resistor sandwiched thereby which are positioned between a center electrode portion and a terminal electrode portion oppositely arranged each other in an insulator consisting of alumina porcelain, can suppress noises or radio frequency interferences generated upon its spark discharge and now has a tendency to be adopted broadly in various combustion engines.
  • the inventors made various experiments and investigations upon the resistor-incorporated spark plug so as to improve the effect for preventing the noises and as a result, one example in which a noise field intensity of the plug is made small by making the length of the resistor large, at least more than 7 mm, regardless of various values of the resistance and the diameter of the center bore of the insulator used for insertion of the resistor, has been provided (refer to Japanese laid open patent No. 45,725/73).
  • the composition of the resistor for use in the spark plug consists of a glass, a ceramic material such as mullite, zircon, alumina, Zirconia and clays as an aggregate, and carbonaceous materials such as glycerin, sugar and polyvinyl alcohol, the composition of the resistor is filled and heat-sealed with the conductive glass between the terminal electrode and discharge electrode portions opposing each other in the center bore of the insulator, and the length of the resultant in the bore is made more than 7 mm, an effective noise preventing effect shall be maintained for a long period of time, but the length of the insulator becomes too long.
  • An object of the present invention is to provide a spark plug incorporating a resistor which is so formed as to eliminate the above described defects.
  • the present invention is based on the recognition of the fact that the noise field intensity (the smaller, the better) rather corresponds to the length of the resistor and not to the resistance value thereof, so that if the space occupied by, the conductive glass is utilized as a part of resistor, the length of the effective resistance portion will be elongated without undesired elongation of the length of the insulator, and accordingly the noise field intensity caused by the spark discharge will be reduced.
  • a spark plug incorporating resistor comprises a ceramic insulator, a metal shell for housing the insulator, an outer electrode connected to the shell and a center electrode opposed to the outer electrode and extended through and sealed in a center bore provided in the insulator, said center electrode being composed of a discharge electrode portion, a terminal electrode portion, a carbonaceous resistor, a conductive glass positioned at one end of the resistor and an auxiliary sealing resistor positioned at the other end of the resistor.
  • the conductive glass, the carbonaceous resistor and the auxiliary resistor are placed between the discharge and the terminal electrode portions.
  • the conductive glass can be replaced by the auxiliary resistor, which mainly consists of a glass and a semiconductive material.
  • the auxiliary resistor may also be added an aggregate, if necessary.
  • the semiconductive material of the auxiliary resistor according to the invention consists of at least one metal oxide such as TiO, Nb O NiO, La O ZrO Th0 and ZnO and at least one metal carbide such as TiC, SiC and B ,C.
  • the aggregate is betonite, clay, zircon or the mixture thereof and the glass is preferably a borosilicate glass.
  • a preferred composition of the auxiliary resistor according to the invention includes 10-60% of the semiconductive material, up to 30% of the aggregate and 40-90% of the glass.
  • the carbonaceous resistor has a composition consisting of 0.24% of the carbonaceous material such as carbon black, glycerin or the like, 10-70% of the aggregate such as clay or zircon and the remainder of a barium borate glass and contains less than 20% of a semiconductive material such as a mixture of TiO and TiC, if necessary, so that the resistor shows a resistance value within the range of l-30 K!) which is necessary for effective preventing the noises.
  • the carbonaceous material such as carbon black, glycerin or the like
  • 10-70% of the aggregate such as clay or zircon and the remainder of a barium borate glass and contains less than 20% of a semiconductive material such as a mixture of TiO and TiC, if necessary, so that the resistor shows a resistance value within the range of l-30 K!) which is necessary for effective preventing the noises.
  • the drawing is a side elevational view, partly in a cross section of a spark plug in accordance with the invention.
  • reference numeral 1 indicates a spark plug ceramic insulator made of porcelain such as high 1 which comprises a small diameter bore 10 for retaining a discharge electrode portion 2 and a large diameterbore 1b for inserting athreaded terminal electrode portion 3, these bores being connected by a tapered shoulder 10.
  • a flange 2a at one end of the electrode portion 2 is retained by the tapered shoulder 10 of the insulator and a discharge end 2b thereof projects from the lower end of the insulator through the small bore 1a.
  • the threaded terminal electrode portion 3 comprises a rod 3a which is placed in the large bore lb of the insulator, a flange 3b which is fixed to the top end of the insulator, a screw portion 3c which is coupled with an external cable (not shown) and a threaded or knurled part 3d for preventing rotation of the terminal electrode portion 3.
  • Numeral 4 designates a carbonaceous resistor consisting of a glass, an aggregate and a carbonaceous material, the resistor being so located between the flange 2a of the discharge electrode portion 2 and the threaded part 3d of the terminal electrode portion 3 in the large bore 1b of the insulator 1 as not directly to contact them.
  • Numeral 5 shows a conductive glass consisting of a glass and a metal, which is inserted between the carbonaceous resistor 4 and the threaded part 3d of the terminal electrode portion 3.
  • Numeral 6 designates an auxiliary sealing resistor inserted between the carbonaceous resistor 4 and the flange 2a of the discharge electrode portion 2 and mainly consisting of a glass and a semiconductive material (or a glass, a semiconductive material and an aggregate).
  • the auxiliary resistor serves for elongation of the length of an effective resistance part in the insulator bore.
  • the auxiliary resistor 6 may be located between'the central resistor 4 and the terminal electrode portion 3, and the conductive glass 5 may in turn be placed between the resistor 4 and the discharge electrode portion 2.
  • the auxiliary resistor in accordance with the invention can be used between the resistor 4 and the terminal and the discharge electrode portions 2, 3 without the conventional conductive glass, and in this case the length of the effective resistance portion can be further elongated.
  • reference numeral 7 shows a metal shell caulked onto the insulator with the aid of an a caulking powder 8 such as talc and a metal packing 9 and numeral 10 designates an outer electrode (usually an earthed electrode) extending from the lower end face of the metal shell and forming a spark gap with the discharge end 2b of the discharge electrode portion therebetween.
  • a caulking powder 8 such as talc
  • metal packing 9 designates an outer electrode (usually an earthed electrode) extending from the lower end face of the metal shell and forming a spark gap with the discharge end 2b of the discharge electrode portion therebetween.
  • the discharge electrode 2 made of a Ni alloy is first inserted into the small bore 1a (diameter: 2.8 mm, length: 16 mm) through the large bore 1b of the center bore formed in the insulator and is engaged or retained by the tapered shoulder 1c, and an electrically conductive glass powder in which a lead borosilicate glass powder is mixed with a copper powder in the mixture ratio by weight of 1:] (refer as a first conductive glass hereinafter) is filled onto the flange 2a of the discharge electrode 2 in a height of 3 mm through the large bore 1b (diameter: 4.6 mm, length: 49.5 mm) and then the carbonaceous resistor powder consisting of 30 parts by weight of barium borate glass, 70 parts by weight of a mixture consisting of gairome-clay and zircon in the mixture ratio by weight of 1:1 and 4 parts by weight of glycerin is superimposed thereon in a height of l 1 mm, thereafter the same conductive glass powder as the
  • the ceramic insulator thus filled with the conductive glass and the resistor material is heated at 970C for 7 minutes to soften the conductive glass seal powders and the resistor composition and then a pressure of l2 Kg/cm is applied to the terminal electrode 3 to force it down into the center bore, whereby the bottom of the terminal electrode, the upper glass seal, the resistor composition, the lower glass seal and the top of the dis charge electrode are bonded and integrated.
  • the thus formed insulator assembly incorporating a resistor is then assembled in a metal shell 7 having 14 mm of a fitting thread. This process results in manufacture of a conventional glass sealed spark plug A incorporating a resistor.
  • a spark plug B in accordance with the invention is provided on the same conditions as those of the spark plug A described just above except that an auxiliary resistor powder consisting of 72 parts by weight of borosilicate glass powder, 5 parts by weight of bentonite, 18 parts by weight of TiO and 5 parts by weight of TiC is used instead of the first conductive glass between the resistor 4 and the discharge electrode portion 2.
  • Another spark plug C in accordance with the invention is provided on the same conditions as those of the spark plug A except that the same auxiliary resistor powder as that of the spark plug B is used instead of the second conductive glass between the resistor 4 and the electrode portion 3.
  • a spark plug D in accordance with the invention is provided in the same manner as the spark plug A except that the same auxiliary resistor powders as those of the spark plugs B and C are used instead of the first and the second conductive glasses between the resistor 4 and the discharge and the terminal electrode portions, respectively.
  • Each of the resultant spark plugs A, B, C and D is tested for the durable life property under load, the temperature property and the noise field intensity. The obtained results are shown in the following Table l.
  • the durable life property under load herein means the variation percentage (within t30%) of the resistance value after 250 hours defined in J IS D5 102-1960, 4, 4, l l and the temperature property means the following value.
  • the resistance value between the discharge and the terminal electrode portions is first determined at room temperature and then the spark plug is subjected to the spark test at 300C for 2 hours and then left to stand for 30 minutes at the room temperature, thereafter, the resistance value is again measured and the variation percentage is determined.
  • the noise field intensity means a measured value around the frequency of MHZ, obtained by the test defined by Japan Radio Technical Council.
  • the noise fieldintensity of the spark plug D having the longest effective resistance portion shows a minimum value, in the noise tions is maintained during the-use of the spark plug for a long period of time. Therefore, there is no fear that the burning or oxidation of carbonaceous matter occurs at the contacting faces of the resistor to the electrode, and hence the resistance value of the resistor becomes stable.
  • the aggregate such asbetonite or the like is used to further rise the noise preventing effect by suppressing the fluidity of the auxiliary resistor during the glass sealing operation and by making the joint'(the boundary) of the aggregate with the carbonaceous resistor linear.
  • the amount of the aggregate added is limited to 30% by weight in the total amount of the field intensity. 15 composition so that upon exceeding this limitation the Then, samples of spark plugs, D D2, 3.
  • the resistance value of the as Show" Table 2 and the auxlllal'y reslstors are auxiliary resistor mainly consisting of glass and semi-, inserted and sealed between the carbonaceous resistor 20 conductive i l referably e to h same value as and the discharge and the terminal electrode Portions or a certain value lower than that of the carbonaceous (without the conventional conductive glass), are proresistor, i to loo-3,000 Q/ Vided and tested and the performancfi of the thus
  • the metal carbide in the auxiliary resistor tamad Spark Plugs are Show" Table according to the invention serves as a kind of reducing Table 2 Semiconductive material Durable Borosilicate Metal oxide, Metal Aggregate life Temper- Noise glass carbide bentonite property ature field (
  • the auxiliary resistor when the mixture consisting of 40 to 90% by weight of glass, 10 to by weight of semiconductive material and up to 30% by-weight of aggregate, instead of the conductive glass is used as an auxiliary resistor to extend the effective resistance portion and a discharge voltage is applied across the discharge electrode portion and the terminal electrode portion, the low contact resistance between the resistor and the electrode porthe metal oxide serves to prevent the deterioration of the durable life property under load of the auxiliary resistor caused by the existence of the metal carbide after heat sealing. Therefore, the auxiliary resistor exhibits an excellent performance when the metal carbide is contained by 01-30% by weight, preferably 05-10% by weight in the total amount of the auxiliary resistor.
  • the resistor incorporating spark plug according to the invention constructed by sealing the carbonaceous resistor with the auxiliary resistor between the discharge and the terminal electrodes opposing each other in the center bore of the ceramic insulator, has sustantially elongated the length of the effective resistance portion, in the insulator bore, so that the noise field intensity produced from the present resistor-incorporated spark plug becomes very small, and thefurther durable life property under load and the temperature property become superior to those of the conventional one and then the effect for preventing noises is certainly maintained during the use of the present resistor-incorporated spark plug for a long period of time.
  • a spark plug comprising a ceramic insulator, a metal shell for housing the insulator, an outer electrode connected to the shell and a center electrode opposed to the outer electrode and extended through and sealed in a center bore provided in the insulator, said center electrode being composed of conductive glasses and a resistor sandwiched by the conductive glasses inserted between a discharge electrode portion and a terminal electrode portion, an improvement comprising using an auxiliary resistor consisting mainly of a glass and a semiconductive material instead of at least one of said conductive glasses, whereby the length of an effective resistance portion of the resistor is elongated.
  • a spark plug as claimed in claim 2, wherein said auxiliary resistor consists of at least one metal oxide and at least one metal carbide as a semiconductor material, an aggregate and a glass.
  • said metal carbide is selected from the group consisting of: TiC, SiC, or B C.
  • a spark plug as claimed in claim 3, wherein said aggregate is selected from the group consisting of: bentonite, clay or zircon.
  • said glass is borosilicate glass.
  • auxiliary resistor is a composition of 10-60% of the semiconductive material, O.130% of the aggregate and 40-90% of the glass.
  • a spark plug as claimed in claim 9, wherein the resistance value of the resistor is 1-30 KQ/cm.

Landscapes

  • Engineering & Computer Science (AREA)
  • Chemical & Material Sciences (AREA)
  • Combustion & Propulsion (AREA)
  • Computer Networks & Wireless Communication (AREA)
  • Signal Processing (AREA)
  • Spark Plugs (AREA)
  • Non-Adjustable Resistors (AREA)
US509217A 1973-09-28 1974-09-25 Spark plug incorporating a resistor for providing a low noise level Expired - Lifetime US3903453A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP10835773A JPS5520355B2 (enrdf_load_stackoverflow) 1973-09-28 1973-09-28

Publications (1)

Publication Number Publication Date
US3903453A true US3903453A (en) 1975-09-02

Family

ID=14482661

Family Applications (1)

Application Number Title Priority Date Filing Date
US509217A Expired - Lifetime US3903453A (en) 1973-09-28 1974-09-25 Spark plug incorporating a resistor for providing a low noise level

Country Status (6)

Country Link
US (1) US3903453A (enrdf_load_stackoverflow)
JP (1) JPS5520355B2 (enrdf_load_stackoverflow)
DE (1) DE2446365A1 (enrdf_load_stackoverflow)
FR (1) FR2246997B1 (enrdf_load_stackoverflow)
GB (1) GB1488677A (enrdf_load_stackoverflow)
ZA (1) ZA746080B (enrdf_load_stackoverflow)

Cited By (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4173731A (en) * 1977-03-02 1979-11-06 Ngk Spark Plug Co., Ltd. Resistor composition for spark plug having a resistor enclosed therein
US4460847A (en) * 1981-07-27 1984-07-17 Champion Spark Plug Company Spark plug
US5760533A (en) * 1995-03-31 1998-06-02 Ngk Spark Plug Co., Ltd. Spark plug for an internal combustion engine
US6557508B2 (en) * 2000-12-18 2003-05-06 Savage Enterprises, Inc. Robust torch jet spark plug electrode
US6583537B1 (en) * 1998-01-28 2003-06-24 Ngk Spark Plug Co., Ltd. Spark plug with built-in resistor
US20110121711A1 (en) * 2009-11-24 2011-05-26 Andreas Benz Spark plug for an internal combustion engine
US9407069B2 (en) 2014-08-10 2016-08-02 Federal-Mogul Ignition Company Spark plug with improved seal
US9751797B2 (en) 2014-08-10 2017-09-05 Federal-Mogul Ignition Company Corona ignition device with improved seal
US10418789B2 (en) * 2016-07-27 2019-09-17 Federal-Mogul Ignition Llc Spark plug with a suppressor that is formed at low temperature

Families Citing this family (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4112330A (en) * 1977-05-20 1978-09-05 General Motors Corporation Metallized glass seal resistor compositions and resistor spark plugs
US4193012A (en) * 1978-10-10 1980-03-11 Champion Spark Plug Company Spark plug seal
JPS6018621B2 (ja) * 1981-05-21 1985-05-11 日本碍子株式会社 エンジン部品
WO1987005006A1 (en) * 1986-02-19 1987-08-27 Dumesnil Maurice E A LOW MELTING GLASS COMPOSITION CONTAINING PbO AND V2O5
DE3905315A1 (de) * 1989-02-21 1990-08-23 Beru Werk Ruprecht Gmbh Co A Elektrisch leitende glaszusammensetzung
DE102018221690A1 (de) * 2018-12-13 2020-06-18 Robert Bosch Gmbh Zündkerzenwiderstandselement und Zündkerze

Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2864884A (en) * 1954-01-25 1958-12-16 Gen Motors Corp Resistor and spark plug embodying same

Patent Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2864884A (en) * 1954-01-25 1958-12-16 Gen Motors Corp Resistor and spark plug embodying same

Cited By (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4173731A (en) * 1977-03-02 1979-11-06 Ngk Spark Plug Co., Ltd. Resistor composition for spark plug having a resistor enclosed therein
US4460847A (en) * 1981-07-27 1984-07-17 Champion Spark Plug Company Spark plug
US5760533A (en) * 1995-03-31 1998-06-02 Ngk Spark Plug Co., Ltd. Spark plug for an internal combustion engine
US6583537B1 (en) * 1998-01-28 2003-06-24 Ngk Spark Plug Co., Ltd. Spark plug with built-in resistor
US6557508B2 (en) * 2000-12-18 2003-05-06 Savage Enterprises, Inc. Robust torch jet spark plug electrode
US20110121711A1 (en) * 2009-11-24 2011-05-26 Andreas Benz Spark plug for an internal combustion engine
US8384278B2 (en) * 2009-11-24 2013-02-26 Robert Bosch Gmbh Leadless package housing having an insulator and composition
US9407069B2 (en) 2014-08-10 2016-08-02 Federal-Mogul Ignition Company Spark plug with improved seal
US9751797B2 (en) 2014-08-10 2017-09-05 Federal-Mogul Ignition Company Corona ignition device with improved seal
US10418789B2 (en) * 2016-07-27 2019-09-17 Federal-Mogul Ignition Llc Spark plug with a suppressor that is formed at low temperature

Also Published As

Publication number Publication date
JPS5059635A (enrdf_load_stackoverflow) 1975-05-23
JPS5520355B2 (enrdf_load_stackoverflow) 1980-06-02
ZA746080B (en) 1975-10-29
GB1488677A (en) 1977-10-12
FR2246997A1 (enrdf_load_stackoverflow) 1975-05-02
FR2246997B1 (enrdf_load_stackoverflow) 1977-11-10
DE2446365A1 (de) 1975-04-17

Similar Documents

Publication Publication Date Title
US3903453A (en) Spark plug incorporating a resistor for providing a low noise level
CA1096605A (en) Resistor composition for spark plug having a resistor enclosed therein
EP1784370B1 (en) Ceramic with improved high temperature electrical properties for use as a spark plug insulator
EP0805534A1 (en) Spark plug for internal combustion engine
JPH0141241B2 (enrdf_load_stackoverflow)
KR101515271B1 (ko) 내연기관용 스파크 플러그
US4001145A (en) Glassy resistor composition for use in a resistor incorporated spark plug
US4144474A (en) Low noise resistance containing spark plug
US5008584A (en) Spark plug having a built-in resistor for suppressing noise signals
US2864884A (en) Resistor and spark plug embodying same
JPS62132765A (ja) 高絶縁性高アルミナ質磁器組成物の製造方法
JP5325302B2 (ja) 内燃機関用スパークプラグ
JP2020534665A (ja) 非導電性微粒子を含んだ点火プラグ・抵抗要素
US2926275A (en) Pgras
US2380579A (en) Spark plug
US3408524A (en) Sparkplug and seal therefor
US2988662A (en) Spark plug with improved auxiliary spark gap
US3349275A (en) Spark plug with a conductive glass seal electrode of glass, copper and zinc
US3659137A (en) Low voltage spark plugs
RU2138090C1 (ru) Композиционный материал для изготовления резистора для свечи зажигания
JP7223851B2 (ja) 点火プラグ抵抗素子および点火プラグ
KR102628082B1 (ko) ZrSiO₄ 상 비율이 증가한 점화 플러그 저항 요소
US3328621A (en) Spark plug with improved intensifier spark gap in the center electrode
JPS62143866A (ja) 高絶縁性高アルミナ質磁器組成物の製造方法
JP2019091646A (ja) スパークプラグ