USRE43758E1 - Spark plug with alloy chip - Google Patents

Spark plug with alloy chip Download PDF

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Publication number
USRE43758E1
USRE43758E1 US11/495,524 US49552406A USRE43758E US RE43758 E1 USRE43758 E1 US RE43758E1 US 49552406 A US49552406 A US 49552406A US RE43758 E USRE43758 E US RE43758E
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US
United States
Prior art keywords
central electrode
spark plug
chip
amount ranging
based alloy
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
US11/495,524
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English (en)
Inventor
Wataru Matsutani
Junichi Kagawa
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
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First worldwide family litigation filed litigation Critical https://patents.darts-ip.com/?family=26504866&utm_source=google_patent&utm_medium=platform_link&utm_campaign=public_patent_search&patent=USRE43758(E1) "Global patent litigation dataset” by Darts-ip is licensed under a Creative Commons Attribution 4.0 International License.
Priority claimed from US08/883,145 external-priority patent/US5793793A/en
Application filed by NGK Spark Plug Co Ltd filed Critical NGK Spark Plug Co Ltd
Priority to US11/495,524 priority Critical patent/USRE43758E1/en
Application granted granted Critical
Publication of USRE43758E1 publication Critical patent/USRE43758E1/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
    • H01T21/00—Apparatus or processes specially adapted for the manufacture or maintenance of spark gaps or sparking plugs
    • H01T21/02—Apparatus or processes specially adapted for the manufacture or maintenance of spark gaps or sparking plugs of sparking plugs
    • 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
    • H01T13/20—Sparking plugs characterised by features of the electrodes or insulation
    • H01T13/39—Selection of materials for electrodes

Definitions

  • the present invention relates to a spark plug for use in internal combustion engines.
  • Ir is easy to oxidize and evaporate in a high temperature range of 900° to 1,000° C. Therefore, if it is directly used in the igniting portion of the electrode, it is more consumed by oxidation and evaporation than by spark. Therefore, the spark plug using Ir in the igniting portion of an electrode is highly durable using low-temperature conditions as in driving on city roads but their endurance drops considerably during continuous running at high speed.
  • a spark plug according to the present invention is comprised of: a central electrode; an insulator provided exterior to the central electrode; a main metallic shell provided exterior to the insulator, a ground electrode coupled at one end to the main metallic shell and which has the other end disposed to face the central electrode; and an igniting portion that is secured to at least one of the central electrode and the ground electrode for forming a spark discharge gap; wherein the igniting portion is made of an alloy based on Ir which contains Rh in an amount ranging from 3 to 50 wt % (50 wt % being not inclusive).
  • the igniting portion of an electrode which forms a spark discharge gap is made of an alloy that is mainly made of Ir and which contains an amount of Rh in the stated range, Therefore, the consumption due to oxidation and evaporation of the Ir component at high temperatures is effectively retarded to thereby realize a highly durable spark plug.
  • FIG. 1 is a partial front sectional view of the spark plug of the invention
  • FIG. 2 is a sectional view showing enlarged the essential part of the same spark plug
  • FIG. 3 is a graph showing the relationship between the Rh content of the alloy forming the igniting portions of the spark plug and the increase in the spark discharge gap (in Example 1 under condition A);
  • FIG. 4 is a graph showing the relationship between the Rh content of the alloy forming the igniting portions of the spark plug and the increase in the spark discharge gap (in Example 1 under condition B);
  • FIG. 5 is a graph showing the relationship between the Rh content of the alloy forming the igniting portions of the park plug and the increase in the spark discharge gap (in Example 1 under condition C).
  • the spark plug according to the present invention has a central electrode, an insulator provided exterior to the central electrode, a main metallic shell provided exterior to the insulator, a ground electrode coupled at one end to the main metallic shell and which has the other end disposed to face the central electrode, and an igniting portion that is secured to either the central electrode or the ground electrode or both for forming a spark discharge gap, wherein the igniting portion is made of an alloy based on Ir which contains Rh in an amount ranging from 3 to 50 wt % (50 wt % being not inclusive).
  • the present inventors have found that if the igniting portion of an electrode which forms a spark discharge gap is made of an alloy that is mainly made of Ir and which contains an amount of Rh in the stated ranger the consumption due to oxidation and evaporation of the Ir component at high temperatures is effectively retarded to thereby realize a highly durable spark plug,
  • a chip made of a metal having the stated composition may be joined by welding to the ground electrode and/or the central electrode.
  • the term “igniting portion” as used herein shall refer to that part of the joined chip which has not been subject to the effect of the compositional change due to welding (e.g., the portion other than that which has been alloyed with the constituent material of the ground or central electrode upon welding),
  • the Rh content of the alloy is less than 3%, the effectiveness of Rh in retarding the oxidation and evaporation of Ir is insufficient to prevent premature consumption of the igniting portion. Hence, the endurance of the spark plug is reduced. In this case, the igniting portion is consumed primarily in the tip end face of the chip welded to the central electrode and/or the ground electrode. However, the lateral sides of the drip may also be consumed if the Rh content is reduced.
  • the Rh content of the alloy is desirably adjusted to lie within such a range that the consumption of the igniting portion is unlikely to occur not only in the tip end face of the chip but also on its lateral sides.
  • the Rh content of the alloy is 50 wt % or more, the melting point of the alloy will drop and the endurance of the spark plug will deteriorate accordingly.
  • the Rh content of the alloy is preferably adjusted to lie within the range of 3 to 50 wt % (50 wt % being not inclusive), desirably 7 to 30 wt %, more desirably 15 to 25 wt %, most desirably 18 to 22 wt %.
  • FIG. 1 shows an embodiment of the present invention.
  • a spark plug 100 has a tubular main metallic shell 1 , an insulator 2 fitted into the metallic shell 1 in such a way that the tip end 21 protrudes from the metallic shell 1 , a central electrode 3 provided within the insulator 2 in such a way that the igniting portion 31 formed at the tip end protrudes from the insulator 2 , and a ground electrode 4 coupled at one end to the main metallic shell 1 as by welding and which has the other end bent laterally such that its lateral aide faces the tip end of the central electrode 3 .
  • the ground electrode 4 has an igniting portion 32 formed in such a way that it faces the igniting portion 31 of the central electrode 3 ; the clearance between the two igniting portions 31 and 32 forms a spark discharge gap g.
  • the insulator 2 is a sintex of a ceramic material such as alumina or aluminum nitride as a main constituent, and it has an axial bore 6 through which the central electrode 3 is to be fitted.
  • the main metallic shell 1 is a cylinderical form made of a metal such as a lowcarbon steel and which provides is a housing for the spark plug 100 .
  • the circumference of the metallic shell 1 has a threaded portion 7 formed to assist in the mounting of the spark plug 100 on an engine block (not shown).
  • the main body 3 a of the central electrode 3 and the main body 4 a of the ground electrode 4 are both typically made of a Ni allloy.
  • the igniting portion 31 of the central electrode 3 and the opposed firing portion 32 of the ground electrode 4 are both made of an alloy based on Ir and which contains Rh in an amount ranging from 3 to 50 wt % (50 wt % being not inclusive).
  • the Rh content of the alloy is desirably adjusted to lie within a range of 7 to 30 wt %, more desirably 15 to 25 wt %, most desirably 18 to 22 wt %.
  • the main body 3 a of the central electrode 3 tapers at the tip end and its tip end face is formed flat
  • a disk-shaped chip having an alloy formula for the igniting portion 31 is placed on the flat tip end face and laser welding, electron beam welding, resistance welding or other suitable welding technique is applied to the periphery of the joined surfaces to form a weld line W, whereby the chip is securely fixed to the tip end face of the central electrode 3 to form the igniting portion 31 .
  • a similar chip is placed on the ground electrode 4 in registry with the position of the igniting portion 31 and a weld line W is similarly formed on the periphery of the joined surfaces, whereby the chip is securely fitted to the ground electrode 4 to form the igniting portion 32 .
  • the chips may be formed from a molten material obtained by mixing the necessary alloy ingredients to give the stated formula and melting the mixture, alternatively, the chips may be formed from a sinter obtained by shaping into a compact a suitable alloy powder or a mixture of the powders of elemental metal components in specified proportions and sintering the compact.
  • a raw material made of the molten alloy may be subjected to a working process including at least one of rolling, forging, drawing, cutting, shearing and blanking steps, whereby the chips are produced in a specified shape. Steps such as rolling, forging and cutting may be performed with the alloy being heated to a specified temperature (to effect “hot” or “warm” working). The temperature for these steps which is variable with the alloy composition may typically be at least 700° C.
  • a molten alloy may be hot rolled to a sheet, which is hot blanked to chips of a specified shape; alternatively, the molten alloy may be hot rolled or forged to a wire or rod shape, which is cut to chips of a specified length.
  • the iridium (Ir) which is the chief component of the chips has low ductility or malleability in its elemental form; however, in the presence of added Rh, the workability of the Ir is improved such that the resulting alloy can be rolled or forged into a sheet, a rod or a wire with great ease compared to the case where Rh is not added.
  • defects such as cracking are less likely to occur in the raw alloy material being in the process of rolling or forging and this in turn contributes to improvements in the efficiency of chip production and the materials yield. It should be noted here that the workability of the raw alloy material will increase with increasing Rn addition.
  • either one of the two opposed igniting portions 31 and 32 may be omitted. If this is the case, the spark discharge gap g is formed between the igniting portion 31 (or the opposed igniting portion 32 ) and the ground electrode 4 (or the central electrode 3 ).
  • the spark plug 100 operates according to the following mode of action,
  • the spark 100 is fitted on an engine block by means of the threaded portion 7 and used as a source to ignite an air-fuel mixture that is supplied into the combustion chamber.
  • the igniting portion 31 and the opposed igniting portion 32 define the spark discharge gap g; since both igniting portions are made of the aforementioned alloy, their consumption due to the oxidation and evaporation of Ir is sufficiently retarded to ensure that the spark discharge gap g will not increase for a prolonged period, thereby extending the life of the spark plug 100 .
  • the result is shown in FIG. 3 in terms of the relationship between the Rh content of the alloy and the increase in the spark discharge gap.
  • the result is shown in FIG. 4 in terms of the relationship between the Rh content of the alloy and the increase in the spark discharge gap.
  • the increase in the spark discharge gap decreased stepwise as the range of the Rh content varied from that of 3 to 50 wt % to 7 to 30 wt % and then to 15 to 25 wt %; in particular, the plugs using chips containing 15 to 25 wt % of Rh exhibited a very high level of endurance in spite of the hostile operating condition.
  • the result is shown in FIG. 5 in terms of the relationship between the Rh content of the alloy and the increase in the spark discharge gap.

Landscapes

  • Engineering & Computer Science (AREA)
  • Manufacturing & Machinery (AREA)
  • Spark Plugs (AREA)
  • Ignition Installations For Internal Combustion Engines (AREA)
US11/495,524 1996-06-28 2006-07-31 Spark plug with alloy chip Expired - Lifetime USRE43758E1 (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
US11/495,524 USRE43758E1 (en) 1996-06-28 2006-07-31 Spark plug with alloy chip

Applications Claiming Priority (7)

Application Number Priority Date Filing Date Title
JP18834796 1996-06-28
JP8-188347 1996-06-28
JP33511996A JP3461670B2 (ja) 1996-06-28 1996-11-28 スパークプラグ及びその製造方法
JP8-335119 1996-11-28
US08/883,145 US5793793A (en) 1996-06-28 1997-06-27 Spark plug
US51321500A 2000-02-23 2000-02-23
US11/495,524 USRE43758E1 (en) 1996-06-28 2006-07-31 Spark plug with alloy chip

Related Parent Applications (1)

Application Number Title Priority Date Filing Date
US08/883,145 Reissue US5793793A (en) 1996-06-28 1997-06-27 Spark plug

Publications (1)

Publication Number Publication Date
USRE43758E1 true USRE43758E1 (en) 2012-10-23

Family

ID=26504866

Family Applications (1)

Application Number Title Priority Date Filing Date
US11/495,524 Expired - Lifetime USRE43758E1 (en) 1996-06-28 2006-07-31 Spark plug with alloy chip

Country Status (6)

Country Link
US (1) USRE43758E1 (de)
EP (2) EP0817341B2 (de)
JP (1) JP3461670B2 (de)
KR (1) KR100355886B1 (de)
CN (1) CN1059293C (de)
DE (1) DE69703011T3 (de)

Families Citing this family (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2002231412A (ja) * 2001-01-31 2002-08-16 Ngk Spark Plug Co Ltd スパークプラグの製造方法及び製造装置
JP4121342B2 (ja) * 2001-11-13 2008-07-23 日本特殊陶業株式会社 クロメート被膜付きプラグ用金属部品及びその製造方法
CN101682175B (zh) * 2008-03-27 2012-06-27 日本特殊陶业株式会社 火花塞和制造火花塞的方法
DE102010032412B4 (de) * 2010-07-27 2012-03-08 Dkt Verwaltungs-Gmbh Verfahren zum Herstellen einer Zündelektrode für eine Vorkammerzündkerze und Vorkammerzündkerze
JP7057935B2 (ja) * 2016-12-22 2022-04-21 石福金属興業株式会社 耐熱性Ｉｒ合金

Citations (30)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US1850819A (en) 1931-03-06 1932-03-22 Wilson H A Co Alloy
GB479540A (en) 1936-09-30 1938-02-08 Alan Richard Powell Improvements in electrodes for sparking plugs
US4324588A (en) 1979-08-17 1982-04-13 Engelhard Corporation Arc erosion resistant composite materials and processes for their manufacture
JPS57130384A (en) 1981-02-04 1982-08-12 Nippon Denso Co Spark plug for internal combustion engine
JPS6258114A (ja) 1985-09-09 1987-03-13 Toshiba Corp ロ−ドサ−ベイシステム
US4700103A (en) 1984-08-07 1987-10-13 Ngk Spark Plug Co., Ltd. Spark plug and its electrode configuration
EP0243529A1 (de) 1986-03-28 1987-11-04 NGK Spark Plug Co. Ltd. Zündkerze
JPS6448891A (en) 1987-07-30 1989-02-23 Erdoelchemie Gmbh Removal of pure aromatics
US4893051A (en) 1981-04-30 1990-01-09 Nippondenso Co., Ltd. Spark plug and the method of manufacturing the same
EP0418055A1 (de) 1989-09-14 1991-03-20 Ngk Spark Plug Co., Ltd Zündkerze
JPH03110779A (ja) 1989-09-25 1991-05-10 Ngk Spark Plug Co Ltd 光センサ内蔵型スパークプラグ
JPH04329286A (ja) 1991-04-30 1992-11-18 Nippondenso Co Ltd スパークプラグの製造方法
JPH05159857A (ja) 1991-12-04 1993-06-25 Ngk Spark Plug Co Ltd 気体燃料機関用スパークプラグ
JPH05335066A (ja) 1992-06-01 1993-12-17 Nippondenso Co Ltd 内燃機関用スパークプラグ
EP0575163A1 (de) 1992-06-17 1993-12-22 Ngk Spark Plug Co., Ltd Zündkerze
EP0587446A1 (de) 1992-09-10 1994-03-16 Ngk Spark Plug Co., Ltd Herstellungsverfahren für Zündkerze
US5320569A (en) 1992-07-27 1994-06-14 Ngk Spark Plug Co., Ltd. Method of making a spark plug
EP0637113A1 (de) 1993-07-26 1995-02-01 Ngk Spark Plug Co., Ltd Zündkerze
JPH0737673A (ja) 1993-07-23 1995-02-07 Ngk Spark Plug Co Ltd スパークプラグ用電極
JPH07268574A (ja) 1994-03-25 1995-10-17 Tanaka Kikinzoku Kogyo Kk イリジウム線の製造方法
US5461275A (en) 1993-07-23 1995-10-24 Ngk Spark Plug Co., Ltd. Spark plug for use in an internal combustion engine
US5465022A (en) * 1992-08-12 1995-11-07 Nippondenso Co., Ltd. Spark plug for internal-combustion engine and manufacture method of the same
JPH0845643A (ja) 1994-08-03 1996-02-16 Nippondenso Co Ltd 内燃機関用スパークプラグ
EP0702093A1 (de) 1994-09-16 1996-03-20 Johnson Matthey Public Limited Company Hochtemperaturbeständiger Formkörper
JPH097733A (ja) 1995-06-15 1997-01-10 Nippondenso Co Ltd 内燃機関用スパークプラグ
GB2302367A (en) 1995-06-15 1997-01-15 Nippon Denso Co I.c. engine spark plug with noble metal chip of Ir-Rh alloy
JPH1032076A (ja) 1996-05-13 1998-02-03 Denso Corp スパークプラグ
US5973443A (en) 1996-05-06 1999-10-26 Alliedsignal Inc. Spark plug electrode tip for internal combustion engine
US6147441A (en) * 1995-12-06 2000-11-14 Denso Corporation Spark plug
GB2479540A (en) 2010-04-13 2011-10-19 Adam Ford Corrupting and erasing data on a storage device when computer casing is broken

Family Cites Families (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN1009840B (zh) * 1988-10-14 1990-10-03 中国有色金属工业总公司昆明贵金属研究所 火花塞用铂基合金

Patent Citations (37)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US1850819A (en) 1931-03-06 1932-03-22 Wilson H A Co Alloy
GB479540A (en) 1936-09-30 1938-02-08 Alan Richard Powell Improvements in electrodes for sparking plugs
US4324588A (en) 1979-08-17 1982-04-13 Engelhard Corporation Arc erosion resistant composite materials and processes for their manufacture
JPS57130384A (en) 1981-02-04 1982-08-12 Nippon Denso Co Spark plug for internal combustion engine
US4893051A (en) 1981-04-30 1990-01-09 Nippondenso Co., Ltd. Spark plug and the method of manufacturing the same
US4700103A (en) 1984-08-07 1987-10-13 Ngk Spark Plug Co., Ltd. Spark plug and its electrode configuration
JPS6258114A (ja) 1985-09-09 1987-03-13 Toshiba Corp ロ−ドサ−ベイシステム
EP0243529A1 (de) 1986-03-28 1987-11-04 NGK Spark Plug Co. Ltd. Zündkerze
JPS6448891A (en) 1987-07-30 1989-02-23 Erdoelchemie Gmbh Removal of pure aromatics
EP0418055A1 (de) 1989-09-14 1991-03-20 Ngk Spark Plug Co., Ltd Zündkerze
JPH03110779A (ja) 1989-09-25 1991-05-10 Ngk Spark Plug Co Ltd 光センサ内蔵型スパークプラグ
JPH04329286A (ja) 1991-04-30 1992-11-18 Nippondenso Co Ltd スパークプラグの製造方法
JPH05159857A (ja) 1991-12-04 1993-06-25 Ngk Spark Plug Co Ltd 気体燃料機関用スパークプラグ
JPH05335066A (ja) 1992-06-01 1993-12-17 Nippondenso Co Ltd 内燃機関用スパークプラグ
EP0575163A1 (de) 1992-06-17 1993-12-22 Ngk Spark Plug Co., Ltd Zündkerze
JPH0636856A (ja) 1992-06-17 1994-02-10 Ngk Spark Plug Co Ltd スパークプラグ
US5440198A (en) 1992-06-17 1995-08-08 Ngk Spark Plug Co., Ltd. Spark plug having a noble metal firing tip bonded to a front end of a center electrode
US5320569A (en) 1992-07-27 1994-06-14 Ngk Spark Plug Co., Ltd. Method of making a spark plug
US5465022A (en) * 1992-08-12 1995-11-07 Nippondenso Co., Ltd. Spark plug for internal-combustion engine and manufacture method of the same
EP0587446A1 (de) 1992-09-10 1994-03-16 Ngk Spark Plug Co., Ltd Herstellungsverfahren für Zündkerze
US5461275A (en) 1993-07-23 1995-10-24 Ngk Spark Plug Co., Ltd. Spark plug for use in an internal combustion engine
JPH0737673A (ja) 1993-07-23 1995-02-07 Ngk Spark Plug Co Ltd スパークプラグ用電極
EP0637113A1 (de) 1993-07-26 1995-02-01 Ngk Spark Plug Co., Ltd Zündkerze
JPH0737674A (ja) 1993-07-26 1995-02-07 Ngk Spark Plug Co Ltd スパークプラグ
US5578895A (en) 1993-07-26 1996-11-26 Ngk Spark Plug Co., Ltd. Spark plug having a noble metal electrode tip
JPH07268574A (ja) 1994-03-25 1995-10-17 Tanaka Kikinzoku Kogyo Kk イリジウム線の製造方法
JPH0845643A (ja) 1994-08-03 1996-02-16 Nippondenso Co Ltd 内燃機関用スパークプラグ
EP0702093A1 (de) 1994-09-16 1996-03-20 Johnson Matthey Public Limited Company Hochtemperaturbeständiger Formkörper
US5853904A (en) 1994-09-16 1998-12-29 Johnson Matthey Public Limited Company High temperature articles
GB2302367A (en) 1995-06-15 1997-01-15 Nippon Denso Co I.c. engine spark plug with noble metal chip of Ir-Rh alloy
JPH097733A (ja) 1995-06-15 1997-01-10 Nippondenso Co Ltd 内燃機関用スパークプラグ
US6094000A (en) 1995-06-15 2000-07-25 Nippondenso Co., Ltd. Spark plug for internal combustion engine
US6147441A (en) * 1995-12-06 2000-11-14 Denso Corporation Spark plug
US5973443A (en) 1996-05-06 1999-10-26 Alliedsignal Inc. Spark plug electrode tip for internal combustion engine
JPH1032076A (ja) 1996-05-13 1998-02-03 Denso Corp スパークプラグ
US5977695A (en) 1996-05-13 1999-11-02 Denso Corporation Spark plug having improved consumption resistance
GB2479540A (en) 2010-04-13 2011-10-19 Adam Ford Corrupting and erasing data on a storage device when computer casing is broken

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
European Search Report, European Application No. EP 99 12 2560, dated Dec. 14, 1999.

Also Published As

Publication number Publication date
JPH1074575A (ja) 1998-03-17
JP3461670B2 (ja) 2003-10-27
KR100355886B1 (ko) 2002-12-26
DE69703011D1 (de) 2000-10-12
EP0975075A3 (de) 2000-02-02
DE69703011T3 (de) 2004-05-27
CN1170980A (zh) 1998-01-21
EP0817341B1 (de) 2000-09-06
EP0817341A1 (de) 1998-01-07
EP0817341B2 (de) 2003-12-10
DE69703011T2 (de) 2001-01-11
CN1059293C (zh) 2000-12-06
KR980006677A (ko) 1998-03-30
EP0975075A2 (de) 2000-01-26

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