JPH01251574A - Spark plug - Google Patents
Spark plugInfo
- Publication number
- JPH01251574A JPH01251574A JP7597688A JP7597688A JPH01251574A JP H01251574 A JPH01251574 A JP H01251574A JP 7597688 A JP7597688 A JP 7597688A JP 7597688 A JP7597688 A JP 7597688A JP H01251574 A JPH01251574 A JP H01251574A
- Authority
- JP
- Japan
- Prior art keywords
- insulator
- tip
- ignition section
- spark plug
- flange
- 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.)
- Pending
Links
- 239000012212 insulator Substances 0.000 claims abstract description 38
- 229910002835 Pt–Ir Inorganic materials 0.000 claims abstract description 3
- 229910052697 platinum Inorganic materials 0.000 claims abstract 3
- 230000007797 corrosion Effects 0.000 claims description 2
- 238000005260 corrosion Methods 0.000 claims description 2
- 229910000510 noble metal Inorganic materials 0.000 claims description 2
- 238000003466 welding Methods 0.000 claims description 2
- 229910001260 Pt alloy Inorganic materials 0.000 claims 1
- 230000005465 channeling Effects 0.000 abstract description 7
- 230000035939 shock Effects 0.000 abstract description 6
- 229910045601 alloy Inorganic materials 0.000 abstract description 5
- 239000000956 alloy Substances 0.000 abstract description 5
- 230000000694 effects Effects 0.000 abstract description 4
- 229910002845 Pt–Ni Inorganic materials 0.000 abstract description 3
- 230000008646 thermal stress Effects 0.000 abstract description 3
- 238000010438 heat treatment Methods 0.000 abstract description 2
- 238000005245 sintering Methods 0.000 abstract 1
- 238000010304 firing Methods 0.000 description 12
- 238000002485 combustion reaction Methods 0.000 description 3
- 239000007788 liquid Substances 0.000 description 3
- 238000005336 cracking Methods 0.000 description 2
- 238000009760 electrical discharge machining Methods 0.000 description 2
- 229910052751 metal Inorganic materials 0.000 description 2
- 239000002184 metal Substances 0.000 description 2
- 229910001020 Au alloy Inorganic materials 0.000 description 1
- 229910000990 Ni alloy Inorganic materials 0.000 description 1
- 230000002159 abnormal effect Effects 0.000 description 1
- 230000002411 adverse Effects 0.000 description 1
- PNEYBMLMFCGWSK-UHFFFAOYSA-N aluminium oxide Inorganic materials [O-2].[O-2].[O-2].[Al+3].[Al+3] PNEYBMLMFCGWSK-UHFFFAOYSA-N 0.000 description 1
- 230000015572 biosynthetic process Effects 0.000 description 1
- 239000011521 glass Substances 0.000 description 1
- 239000003353 gold alloy Substances 0.000 description 1
- 229910052741 iridium Inorganic materials 0.000 description 1
- 238000004519 manufacturing process Methods 0.000 description 1
- 239000003566 sealing material Substances 0.000 description 1
Landscapes
- Spark Plugs (AREA)
Abstract
Description
【発明の詳細な説明】
（産業上の利用分野）
この発明は、内燃機関に使用されるセミ沿面、フル沿面
スパークプラグに関する。DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to semi-creeping and full-creeping spark plugs used in internal combustion engines.
（従来の技術）
従来、内燃機間に使用されるスパークプラグは、中心電
極の発火部の円周部を外側電極で囲んだセミ沿面スパー
クプラグや、さらに中心電極の発火部を上記円周部の外
側電極より外方に突出させたフル沿面スパークプラグが
主なものである。(Prior Art) Conventionally, spark plugs used between internal combustion engines include semi-climbing spark plugs in which the firing part of the center electrode is surrounded by an outer electrode, and spark plugs in which the firing part of the center electrode is surrounded by the circumferential part. The main type is a full creepage spark plug that protrudes outward from the outer electrode.
（発明が解決しようとする課題）
しかしながら、上記従来のものにおいて、内燃機関に使
用されるセミ沿面、フル沿面スパークプラグの場合には
、プラグの構造上、スパークプラグの発火部の周囲が液
状ガソリンに濡れ易くなり、このとき絶縁体が液状ガソ
リンに濡れると、発火による放電加工を受けることにな
り、絶縁体の表面に浅い溝ができるチャンネリングが発
生し易いものである。このため、このチャンネリングを
原因としてスパークプラグ自体の強度が著しく劣化して
しまったり、また発火による熱衝撃によって絶縁体の破
損等が起こってしまう欠点がある。そこで、この発明は
上記従来のものの持つ欠点を改善するものであり、チャ
ンネリング等に対する強度の強いスパークプラグを得よ
うとすると共に、熱応力による絶縁体の破損を防止しよ
うとするものである。(Problem to be Solved by the Invention) However, in the above-mentioned conventional spark plugs, in the case of semi-creeping and full-creeping spark plugs used in internal combustion engines, due to the structure of the plug, the area around the ignition part of the spark plug is liquid gasoline. At this time, if the insulator gets wet with liquid gasoline, it will be subjected to electrical discharge machining due to ignition, and channeling, which is the formation of shallow grooves on the surface of the insulator, is likely to occur. For this reason, there are disadvantages in that the strength of the spark plug itself is significantly deteriorated due to this channeling, and the insulator may be damaged due to thermal shock caused by ignition. Therefore, the present invention aims to improve the above-mentioned drawbacks of the conventional spark plug, and aims to provide a spark plug with strong resistance to channeling, etc., and to prevent damage to the insulator due to thermal stress.
（課題を解決するための手段）
そのために、セミ沿面又はフル沿面のスパークプラグに
おいて、中心電極の先端に鍔部に成形された発火部を設
けると共に、上記発火部を絶縁体と共に、同時焼結して
なるものである。(Means for solving the problem) For this purpose, in a semi-creeping or full-creeping spark plug, a firing part formed in the flange is provided at the tip of the center electrode, and the firing part is simultaneously sintered together with an insulator. This is what happens.
（作用）
上記構成を具えるので、発火部が中心電極の先端の鍔部
にのみ限定されることから、発火部周辺が液状ガソリン
によって濡れても、絶縁体部分には放電加工が受けにく
くなることからチャンネリングの発生を防ぐことができ
、さらに絶縁体の割れを生じやすい穴部を鍔部によって
覆ってしまい発火による被熱を最小限とすることができ
、しかも発火部が絶縁体と一体焼成されているため熱応
力が小さくなり、絶縁体の破損を防止することができる
。(Function) With the above configuration, the ignition part is limited to the flange at the tip of the center electrode, so even if the area around the ignition part gets wet with liquid gasoline, the insulator part is less susceptible to electrical discharge machining. Therefore, channeling can be prevented from occurring, and the flange covers the hole where cracks in the insulator are likely to occur, minimizing heat exposure due to ignition.Moreover, the ignition part is integrated with the insulator. Since it is fired, thermal stress is reduced and damage to the insulator can be prevented.
（実施例） この発明を図に示す実施例により更に説明する。(Example) This invention will be further explained with reference to embodiments shown in the drawings.
（１）は、この発明の実施例であるスパークプラグであ
り、このスパークプラグ（１）はアルミナ等からなる絶
縁体（２）、主体金具（３）、ネジ部（４）及び中心電
極（５）の端部の発火部（６）の周囲に設けられた外側
電極（７）から構成されているものである。このとき、
外側電極（７）に囲まれている発火部（６）の先端は鍔
部をしているものである。この鍔部をした発火部（６）
はＰＬ、ＰＬ−ＩｒあるいはＰｔ−Ｎｉ等の合金を用い
るものであり、発火部（６）に周設される絶縁体（２）
の焼成時に同時焼成することによって、絶縁体（２）の
焼成による熱収縮に伴って、絶縁体（２）の先端に保持
されるものである。このため、発火部（６）の先端が鍔
部であることから、火花の発生位置が鍔部となっている
発火部（６）の端縁に限定されることから、発火部（６
）に周設される絶縁体（２）の先端表面には火花が伝わ
りにくくなり、その結果、絶縁体（２〉に生じ易いチャ
ンネリングを防止することができると共に、熱衝撃の影
響を一番受は易い発火部（６）と絶縁体（２）の境界が
、鍔部によって被熱が低減させることになるため熱衝撃
に起因する絶縁体（２）の割れを防ぐことができるもの
である。なお、中心電極（５）の上には中間電極（８）
が載置されて電気的に接続され、この中間電極（８）上
に公知の抵抗体（９）が導電性ガラスシール材（ｌＯ）
によって挟持され端子電極（１１）と共に加熱封着され
ており、発火部（６）と外側電極（７）との間に絶縁体
先端面（１２）に沿って気中の火花間隔（１３）を形成
したセミ沿面スパークプラグである。又、第３図は第２
図において気中間隙をもたない絶縁体先端面に沿った火
花間隙（１４）を形成したフル沿面スパークプラグであ
る。さらに、発火部（６）の鍔部の製法としては第４図
に示すように、耐熱性、耐食性を有する、例えはＮ１合
金、Ｐｔ、ｒｒ、Ｐｔ−ｒｒ金合金はｐｔ−Ｎｉ合金等
からなるリング部材（１６）を、絶縁体（２）に一体焼
成されたｐｔ、Ｐｔ−Ｉｒ合金あるいはＰｔ−Ｎｉ合金
等の貴金属線（１５）の先端に嵌合した後、その嵌合部
をレーザー溶接（Ａ）を施して形成することができる。(1) is a spark plug that is an embodiment of the present invention, and this spark plug (1) includes an insulator (2) made of alumina or the like, a metal shell (3), a threaded portion (4), and a center electrode (5). ) consists of an outer electrode (7) provided around a firing section (6) at the end of the tube. At this time,
The tip of the firing part (6) surrounded by the outer electrode (7) is a flange. Ignition part with this flange (6)
uses an alloy such as PL, PL-Ir or Pt-Ni, and the insulator (2) surrounding the firing part (6)
By firing simultaneously with the firing of the insulator (2), it is held at the tip of the insulator (2) as the insulator (2) shrinks due to heat shrinkage. Therefore, since the tip of the ignition part (6) is the flange, the position where sparks are generated is limited to the edge of the ignition part (6), which is the flange.
), it becomes difficult for sparks to be transmitted to the tip surface of the insulator (2), and as a result, it is possible to prevent channeling that tends to occur in the insulator (2), and to minimize the effects of thermal shock. The boundary between the ignition part (6) and the insulator (2), which is easily susceptible to receiving heat, is reduced by the flange, which can prevent the insulator (2) from cracking due to thermal shock. Note that an intermediate electrode (8) is placed above the center electrode (5).
is mounted and electrically connected, and a known resistor (9) is placed on this intermediate electrode (8) with a conductive glass sealing material (lO).
It is sandwiched by the terminal electrode (11) and heat-sealed together with the terminal electrode (11), and an air spark interval (13) is created along the insulator tip surface (12) between the firing part (6) and the outer electrode (7). This is a semi-creeping spark plug. Also, Figure 3 shows the second
The figure shows a full creepage spark plug in which a spark gap (14) is formed along the tip surface of an insulator without an air gap. Furthermore, as shown in Figure 4, the flange of the ignition part (6) can be made from N1 alloy, Pt, rr, Pt-rr gold alloy, pt-Ni alloy, etc., which have heat resistance and corrosion resistance. After fitting the ring member (16) to the tip of the noble metal wire (15) such as PT, Pt-Ir alloy, or Pt-Ni alloy, which is integrally fired with the insulator (2), the fitting part is heated with a laser beam. It can be formed by welding (A).
かかる鍔部の形成においては、予め鍔部を具えてこれを
絶縁体（２）に埋設し焼成したものに比へて、絶縁体先
端面（１２）と鍔内面との間に隙間が生じなく、このた
め鍔の異常加熱を防止して耐電極消耗性に優れたものと
することができる。In forming such a flange, no gap is created between the insulator tip surface (12) and the inner surface of the flange, compared to the case where the flange is provided in advance, embedded in the insulator (2), and fired. Therefore, abnormal heating of the collar can be prevented and the electrode can have excellent wear resistance.
（発明の効果）
以上のとおり、発火部の先端を鍔部とすることにより、
絶縁体に悪影響を与えるチャンネリングや、熱衝撃によ
る割れを防ぐことができるので、高温になりやすいエン
ジン等に最適な耐久性に冨んだセミ沿面又はフル沿面の
スパークプラグを得ることのできる優れた効果を有する
ものである。(Effect of the invention) As described above, by making the tip of the firing part the flange part,
This feature prevents channeling, which adversely affects the insulator, and cracking due to thermal shock, making it possible to obtain semi-creeping or full-creeping spark plugs that are highly durable and ideal for engines that are prone to high temperatures. It has the following effects.
第１図はこの発明の第１実施例であるセミ沿面スパーク
プラグの部分断面図であり、第２図は第１図の要部拡大
断面図、第３図は第２実施例のフル沿面スパークプラグ
の要部拡大断面図、ざらに第４図は鍔部の製法を示す要
部拡大断面図である。
ｌ・・・スパークプラグ ２・・・絶縁体 ３・・・主
体金具 ４・・・ネジ部 ５・・・中心電極 ６・・・
発火部７・・・外側電極 １２・・・絶縁体先端面 １
６・・・リング状部材
特許出願人 代理人 弁理士 藤木三幸第１図
第２図
第３図
第４図Fig. 1 is a partial sectional view of a semi-creeping spark plug which is the first embodiment of the present invention, Fig. 2 is an enlarged sectional view of the main part of Fig. 1, and Fig. 3 is a full creeping spark plug of the second embodiment. FIG. 4 is an enlarged sectional view of the main part of the plug, roughly showing a method of manufacturing the flange. l... Spark plug 2... Insulator 3... Metal shell 4... Threaded portion 5... Center electrode 6...
Firing part 7...Outer electrode 12...Insulator tip surface 1
6... Ring-shaped member patent applicant Representative Patent attorney Miyuki Fujiki Figure 1 Figure 2 Figure 3 Figure 4
Claims (2)
設けてなるセミ沿面又はフル沿面スパークプラグにおい
て、上記発火部を絶縁体と共に、同時焼結してなるスパ
ークプラグ。(1) A semi-climbing or full-climbing spark plug comprising a flange-shaped igniting part at the tip of a center electrode, in which the igniting part is co-sintered together with an insulator.
−Ｎｉ等のＰｔ合金からなる貴金属線を絶縁体先端面か
ら突出するように埋設して焼成し、この突出部に耐熱性
、耐食性からなるリング状部材を嵌合して、その嵌合部
をレーザー溶接にて接合した発火部を具えてなる請求項
（１）記載のスパークプラグ。(2) Pt or Pt-Ir, Pt in the small diameter hole at the tip of the insulator
- A noble metal wire made of a Pt alloy such as Ni is embedded and fired so as to protrude from the tip surface of the insulator, and a heat-resistant and corrosion-resistant ring-shaped member is fitted to this protrusion, and the fitted part is The spark plug according to claim 1, comprising an ignition portion joined by laser welding.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP7597688A JPH01251574A (en) | 1988-03-31 | 1988-03-31 | Spark plug |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP7597688A JPH01251574A (en) | 1988-03-31 | 1988-03-31 | Spark plug |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH01251574A true JPH01251574A (en) | 1989-10-06 |
Family
ID=13591786
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP7597688A Pending JPH01251574A (en) | 1988-03-31 | 1988-03-31 | Spark plug |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH01251574A (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2008021643A (en) * | 2006-06-14 | 2008-01-31 | Ngk Spark Plug Co Ltd | Semi-creepage spark plug |
| US9030086B2 (en) | 2012-05-07 | 2015-05-12 | Federal-Mogul Ignition Company | Shrink-fit ceramic center electrode |
-
1988
- 1988-03-31 JP JP7597688A patent/JPH01251574A/en active Pending
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2008021643A (en) * | 2006-06-14 | 2008-01-31 | Ngk Spark Plug Co Ltd | Semi-creepage spark plug |
| US9030086B2 (en) | 2012-05-07 | 2015-05-12 | Federal-Mogul Ignition Company | Shrink-fit ceramic center electrode |
| US9502865B2 (en) | 2012-05-07 | 2016-11-22 | Federal-Mogul Ignition Company | Shrink fit ceramic center electrode |
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