JPS592152B2 - Method for manufacturing spark plugs for internal combustion engines - Google Patents
Method for manufacturing spark plugs for internal combustion enginesInfo
- Publication number
- JPS592152B2 JPS592152B2 JP56068758A JP6875881A JPS592152B2 JP S592152 B2 JPS592152 B2 JP S592152B2 JP 56068758 A JP56068758 A JP 56068758A JP 6875881 A JP6875881 A JP 6875881A JP S592152 B2 JPS592152 B2 JP S592152B2
- Authority
- JP
- Japan
- Prior art keywords
- tip
- center electrode
- welding
- spark plug
- noble metal
- 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
Links
Landscapes
- Spark Plugs (AREA)
Description
【発明の詳細な説明】
本発明は火花放電部となる中心電極の先端に貴金属チッ
プを設けた内燃機関用点火プラグ（以下単に点火プラグ
という）の製造方法に関する。DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for manufacturing a spark plug for an internal combustion engine (hereinafter simply referred to as a spark plug) in which a noble metal tip is provided at the tip of a center electrode that serves as a spark discharge portion.
貴金属チップを火花放電部に設けた従来周知の点火プラ
グの製造方法では、例えば特開昭５１−６６９４５号公
報に見られるように、チップ自体に大径部と小径部を設
け、且つ上記公報の方法ではその大径部を中心電極の先
端に設けた穴ぐり部に挿入し、通電してジュール熱で加
熱し且つ加圧してかしめるものであり、または単に抵抗
溶接によってチップを固定することが行なわれ、いずれ
の場合も貴金属チップに大径部と小径部が在るため、非
常に大きなチップを必要とした。In a conventionally well-known manufacturing method of a spark plug in which a noble metal tip is provided in the spark discharge portion, the tip itself is provided with a large diameter portion and a small diameter portion, as shown in, for example, Japanese Patent Application Laid-Open No. 51-66945, and the method described in the above publication is The method involves inserting the large diameter part into a hole provided at the tip of the center electrode, applying electricity to heat it with Joule heat, and applying pressure to caulk it, or simply fixing the tip by resistance welding. In both cases, the noble metal tip had a large diameter part and a small diameter part, so a very large tip was required.
そのため、耐消耗性および飛火、着火性という基本的性
能にはすぐれているが、チップの体積が大きいことから
高価格となり、例えば数百刃７月という大量生産向きで
はなく、そして火花消耗に不必要な部分にまで貴金属が
使用されているため過剰品質となり、資源の無１駄使い
になる。Therefore, it has excellent basic performance such as wear resistance, flying sparks, and ignitability, but the large volume of the tip makes it expensive, and it is not suitable for mass production of several hundred blades, for example, and is not suitable for spark consumption. Precious metals are used even in the necessary parts, resulting in excessive quality and a waste of resources.
さらに大径部と小径部の存在により貴金属チップの加工
コストが高くなる等の欠点があった。Furthermore, the presence of the large-diameter portion and the small-diameter portion has the disadvantage that the machining cost of the noble metal tip increases.
本発明は上記従来技術の欠点を克服するものであって、
それ数本発明の目的は従来に比し著しく小さい貴金属チ
ップを用いて、従来のものと同様な性能が得られる点火
プラグの製造方法を提供することである。The present invention overcomes the drawbacks of the prior art described above, and comprises:
It is therefore an object of the present invention to provide a method of manufacturing a spark plug that uses a precious metal tip that is significantly smaller than that of the conventional spark plug, and that provides performance similar to that of the conventional spark plug.
上記目的を達成するため、本発明による点火プラグの製
造方法の特徴は中心電極の先端に貴金属チップを溶接し
た後に発火部となる中心電極の先端の部分をその胴部よ
り小径に加工することであり、これによって中心電極先
端へのチップの溶接を好適な条件のもとで行なえるよう
にしたものである。In order to achieve the above object, the method for manufacturing a spark plug according to the present invention is characterized by welding a noble metal tip to the tip of the center electrode and then processing the tip of the center electrode, which will become the ignition part, to have a smaller diameter than the body. This allows the tip to be welded to the tip of the center electrode under suitable conditions.
次に図面を参照のもとに本発明の実施例について説明す
る。Next, embodiments of the present invention will be described with reference to the drawings.
第１図および第２図は本発明によって製造された点火プ
ラグを示し、１は耐熱性、耐蝕性および導通性のある卑
金属、例えばＮｉ−Ｃｕ等からなる中心電極であり、中
心電極１０発火部となる先端部分は絶縁碍子３に保持さ
れている胴部１ａより小径に形成されている。1 and 2 show a spark plug manufactured according to the present invention, in which 1 is a center electrode made of a heat-resistant, corrosion-resistant and conductive base metal, such as Ni-Cu, and the center electrode 10 is a ignition part. The tip end portion is formed to have a smaller diameter than the body portion 1a held by the insulator 3.
その小径部１ｂの先端に、好ましくは白金チップである
貴金属チップ２が溶接されており、このチップ２は例え
ば直径０．７ｒｒｔＩｆｔ、厚さ０．３ｒＭｎの微小な
円板からなっている。A noble metal tip 2, preferably a platinum tip, is welded to the tip of the small diameter portion 1b, and this tip 2 is made of a minute disk with a diameter of 0.7 rrtIft and a thickness of 0.3 rMn, for example.
円錐部１Ｃが胴部１ａと小径部１ｂの間に設けられてい
る。A conical portion 1C is provided between the body portion 1a and the small diameter portion 1b.
絶縁碍子３の軸穴３ａの上部には炭素鋼からなる中軸４
が挿通しており、中軸４の頭部には黄銅等からなる端子
５がねじ込み固定されている。At the top of the shaft hole 3a of the insulator 3 is a center shaft 4 made of carbon steel.
is inserted through the center shaft 4, and a terminal 5 made of brass or the like is screwed and fixed to the head of the center shaft 4.
６は円筒状のノ・ウジングであつて、耐熱性、耐蝕性お
よび導電性のある金属で構成され、ハウジング６の内側
にはリング状の気密パツキン７およびかしめリング８を
介して絶縁碍子３が固定されている。Reference numeral 6 denotes a cylindrical housing made of heat-resistant, corrosion-resistant, and conductive metal. Inside the housing 6, an insulator 3 is attached via a ring-shaped airtight packing 7 and a caulking ring 8. Fixed.
なお、ハウジング６はエンジンブロックに固定するため
のねじ部６ａを備えている。Note that the housing 6 includes a threaded portion 6a for fixing to the engine block.
ハウジング６の下端面には接地電極９が溶接により固定
され、この接地電極も耐熱性耐蝕性および導電性のある
金属からなっている。A ground electrode 9 is fixed to the lower end surface of the housing 6 by welding, and this ground electrode is also made of heat-resistant, corrosion-resistant, and electrically conductive metal.
１０は絶縁碍子３の軸穴３ａ内に封着された導電性グラ
スシール層であって、銅粉末と低融点ガラスから構成さ
れており、このシール層１０で中軸４と中心電極１とを
電気的に接続すると共に、両者を絶縁碍子３の軸穴３ａ
に固定する役割を果している。A conductive glass seal layer 10 is sealed in the shaft hole 3a of the insulator 3, and is made of copper powder and low-melting glass. and connect them both through the shaft hole 3a of the insulator 3.
It plays the role of fixing the
本発明による点火プラグの製造方法は中心電極１の先端
に対する貴金属チップ２の溶接に関し、中心電極１の先
端部分を小径に加工する前に、チップ２を中心電極１の
先端に溶接することを特徴としている。The spark plug manufacturing method according to the present invention relates to welding the noble metal tip 2 to the tip of the center electrode 1, and is characterized in that the tip 2 is welded to the tip of the center electrode 1 before the tip of the center electrode 1 is processed to have a small diameter. It is said that
即ち、第３図はチップ２を溶接する前の中心電極１であ
って、点火プラグに組付けられる前の単一部品の状態を
示し、このような状態で貴金属チップ２を中心電極１の
先端に溶接して第４図の状態にする。That is, FIG. 3 shows the state of the center electrode 1 before the tip 2 is welded to it as a single component before it is assembled into a spark plug. In this state, the noble metal tip 2 is attached to the tip of the center electrode 1. Weld it to the state shown in Figure 4.
なお、その溶接は好ましくは抵抗溶接であるが、一般に
は溶接部を加熱し且つ圧力を加えた状態で溶接が行なわ
れる。The welding is preferably resistance welding, but generally the welding is carried out with the welded part heated and pressure applied.
そのように貴金属チップ２を中心電極１の先端に溶接し
た後に、着火性および飛火性を向上するため中心電極１
の先端の部分を、好ましくは旋削などの切削により加工
して胴部１ａより小径にする。After welding the noble metal tip 2 to the tip of the center electrode 1, the center electrode 1 is welded to improve ignitability and spark flying properties.
The distal end portion is preferably processed by cutting such as turning to have a diameter smaller than that of the body portion 1a.
第５図はそのように中心電極１の先端部分が小径にされ
た状態を示している。FIG. 5 shows the state in which the tip portion of the center electrode 1 is made small in diameter.
本発明は上記のように貴金属チップ２を溶接した後に中
心電極１の先端部分を小径にすることによって、チップ
２の良好な溶接を実現したものである。The present invention realizes good welding of the tip 2 by reducing the diameter of the tip of the center electrode 1 after welding the noble metal tip 2 as described above.
もし、中心電極１を冷間鍛造などにより、第６図に示す
ように、チップの溶接の前に先細形状に加工し、その後
に白金等のチップ２を溶接したのでは充分に信頼性のあ
る接合面積がとれず、使用中において高温および燃焼ガ
スという腐食ガス中にさらされるので、高温酸化腐食に
より貴金属チップ２が剥離する現象を呈する。If the center electrode 1 is processed into a tapered shape by cold forging or the like before welding the tip, as shown in Fig. 6, and then the tip 2 made of platinum or the like is welded, the reliability will be insufficient. Since the bonding area is not sufficient and the noble metal tip 2 is exposed to high temperature and corrosive gas such as combustion gas during use, the noble metal tip 2 exhibits a phenomenon of peeling due to high temperature oxidation corrosion.
そのため充分に信頼性のある溶接面積（合金層が形成さ
れている面積）が必要とされるが、それを確保しようと
すると溶接による熱により先端の小径部が座屈してしま
い製品としての形状を保つことができない。Therefore, a sufficiently reliable welding area (area where the alloy layer is formed) is required, but if this is attempted, the small diameter part of the tip will buckle due to the heat from welding, resulting in the shape of the product being deteriorated. I can't keep it.
本発明によれば、充分な信頼性のある溶接面積を確保す
ることができ、そのため使用中に貴金属チップ２の脱落
や剥離が生じることのない高品質の点火プラグが得られ
る。According to the present invention, a sufficiently reliable welding area can be secured, and therefore a high-quality spark plug can be obtained in which the noble metal tip 2 does not fall off or peel off during use.
第７図はチップが溶接されろ中心電極先端の小径部の座
屈を実験的に示したもので、横軸は溶接電流を示し、縦
軸は溶接面積（接合面積）を係で示したもので、パラメ
ータとして電極先端の直径を用いている。Figure 7 shows experimentally the buckling of the small diameter part at the tip of the center electrode when the tip is welded.The horizontal axis shows the welding current, and the vertical axis shows the welding area (joint area) in terms of the ratio. The diameter of the electrode tip is used as a parameter.
なお、ここで使用した貴金属は白金であり、直径０．７
ｍ、厚さ０．３ｍｙｎのものを用いた。The precious metal used here is platinum, and the diameter is 0.7
A material having a thickness of 0.3 mym and a thickness of 0.3 myn was used.
この図からも明らかなように、小径部にチップを溶接す
れば座屈することがわかる。As is clear from this figure, if the tip is welded to the small diameter part, it will buckle.
第８図はそのような座屈について更に詳しく実験し、そ
の結果を小径部の直径りと長さ１との関係で示したもの
であって、図中に斜線を施した領域が接合面積１００係
をとれない領域であって、従ってその範囲内のものでは
溶接後に切削等により小径に加工する本発明の方法が極
めて有効なものとなる。Figure 8 shows the results of a more detailed experiment on such buckling in terms of the relationship between the diameter of the small diameter part and the length 1, and the shaded area in the figure is the area where the joint area is 100. Therefore, for objects within this range, the method of the present invention, in which the diameter is reduced by cutting or the like after welding, is extremely effective.
なお、貴金属チップ２としては白金のように貴金属単品
でもよいが、Ｐｔ−Ｉ ｒ、 Ｐｔ−Ｒｈのように合金
であってもよいことは云うまでもない。Note that the noble metal chip 2 may be a single noble metal such as platinum, but it goes without saying that it may be an alloy such as Pt-Ir or Pt-Rh.
また、中心電極１の先端の加工法は切削に限られるもの
ではなく、絞り加工や冷間鍛造等でもよい。Furthermore, the method of processing the tip of the center electrode 1 is not limited to cutting, but may also be drawing, cold forging, or the like.
さらに本発明は中心電極先端と対向する接地電極に貴金
属を接合した点火プラグの中心電極に適用することもで
きない。Further, the present invention cannot be applied to the center electrode of a spark plug in which a noble metal is bonded to the ground electrode facing the tip of the center electrode.
従って、本発明によれば、従来のものに比し著しく小さ
い貴金属チップを中心電極の先端に好適に溶接すること
ができ、従来のものと同様な性能が得られる点火プラグ
を極めて安価に提供し得るという著しい効果がある。Therefore, according to the present invention, a precious metal tip that is significantly smaller than conventional ones can be suitably welded to the tip of the center electrode, and a spark plug that can obtain the same performance as conventional ones can be provided at an extremely low cost. There is a significant effect of gaining.
第１図は本発明によって製造された点火プラグの部分断
面側面図、第２図は第１図の点火プラグの要部拡大断面
図、第３図は貴金属チップを溶接する前の中心電極の側
面図、第４図はチップ溶接。
後の中心電極の側面図、第５図はチップ溶接後に先端部
を加工した中心電極の側面図、第６図は一般的な中心電
極の側面図、第７図は中心電極の先端にチップを溶接す
る際の座屈挙動を示すグラフ、そして第８図は中心電極
の先端形状とチップの溶接面積の関係を示すグラフであ
る。
図中、１・・・中心電極、１ａ・・・中心電極の胴部、
１ｂ・・・小径部、２・・・貴金属チップ。Fig. 1 is a partially sectional side view of a spark plug manufactured according to the present invention, Fig. 2 is an enlarged sectional view of the main part of the spark plug shown in Fig. 1, and Fig. 3 is a side view of the center electrode before welding the noble metal tip. Figure 4 shows chip welding. Figure 5 is a side view of the center electrode with the tip processed after tip welding, Figure 6 is a side view of a typical center electrode, and Figure 7 is a side view of the center electrode with a tip at the tip. A graph showing the buckling behavior during welding, and FIG. 8 is a graph showing the relationship between the tip shape of the center electrode and the welding area of the tip. In the figure, 1...center electrode, 1a...body of center electrode,
1b...Small diameter part, 2...Precious metal tip.
Claims (1)
径になっており且つその小径部の先端には貴金属もしく
はその合金からなるチップが熱および圧力を加えること
により溶接されている点火プラグの製造方法において、 前記中心電極の前記小径部を前記チップが前記中心電極
の先端に溶接された後に加工することを特徴とする内燃
機関用点火プラグの製造方法。 ２、特許請求の範囲第１項に記載の製造方法において、
前記小径部を切削によって加工する内燃機関用点火プラ
グの製造方法。[Scope of Claims] 1. The tip of the center electrode has a smaller diameter than the body of the center electrode, and a tip made of a noble metal or an alloy thereof is attached to the tip of the small diameter portion by applying heat and pressure. A method for manufacturing a welded spark plug for an internal combustion engine, characterized in that the small diameter portion of the center electrode is processed after the tip is welded to the tip of the center electrode. 2. In the manufacturing method according to claim 1,
A method of manufacturing a spark plug for an internal combustion engine, comprising machining the small diameter portion by cutting.
Priority Applications (5)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP56068758A JPS592152B2 (en) | 1981-05-07 | 1981-05-07 | Method for manufacturing spark plugs for internal combustion engines |
| US06/620,484 US4699600A (en) | 1981-04-30 | 1984-06-14 | Spark plug and method of manufacturing the same |
| US06/712,917 US4893051A (en) | 1981-04-30 | 1985-03-18 | Spark plug and the method of manufacturing the same |
| US08/073,706 USRE35429E (en) | 1981-04-30 | 1993-06-09 | Spark plug and the method of manufacturing the same |
| US08/073,713 USRE34778E (en) | 1981-04-30 | 1993-06-09 | Spark plug and method of manufacturing the same |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP56068758A JPS592152B2 (en) | 1981-05-07 | 1981-05-07 | Method for manufacturing spark plugs for internal combustion engines |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS57182990A JPS57182990A (en) | 1982-11-11 |
| JPS592152B2 true JPS592152B2 (en) | 1984-01-17 |
Family
ID=13382964
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP56068758A Expired JPS592152B2 (en) | 1981-04-30 | 1981-05-07 | Method for manufacturing spark plugs for internal combustion engines |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS592152B2 (en) |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS59230282A (en) * | 1983-06-13 | 1984-12-24 | 株式会社デンソー | Spark plug for internal combustion engine |
Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US2296033A (en) * | 1941-01-18 | 1942-09-15 | Gen Motors Corp | Spark plug |
| JPS50157733A (en) * | 1974-01-31 | 1975-12-19 | ||
| JPS5187637A (en) * | 1975-01-30 | 1976-07-31 | Ngk Spark Plug Co | TENKASENDENKYOKUJIKUNIKINZOKUCHITSUPUDENKYOKUOSETSUGOSURUHOHO |
| JPS51140034A (en) * | 1975-05-09 | 1976-12-02 | Bosch Gmbh Robert | Ignition plug for internal combustion engine |
| JPS5338046U (en) * | 1976-09-08 | 1978-04-03 |
Family Cites Families (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS504132U (en) * | 1973-05-12 | 1975-01-17 |
-
1981
- 1981-05-07 JP JP56068758A patent/JPS592152B2/en not_active Expired
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US2296033A (en) * | 1941-01-18 | 1942-09-15 | Gen Motors Corp | Spark plug |
| JPS50157733A (en) * | 1974-01-31 | 1975-12-19 | ||
| JPS5187637A (en) * | 1975-01-30 | 1976-07-31 | Ngk Spark Plug Co | TENKASENDENKYOKUJIKUNIKINZOKUCHITSUPUDENKYOKUOSETSUGOSURUHOHO |
| JPS51140034A (en) * | 1975-05-09 | 1976-12-02 | Bosch Gmbh Robert | Ignition plug for internal combustion engine |
| JPS5338046U (en) * | 1976-09-08 | 1978-04-03 |
Also Published As
| Publication number | Publication date |
|---|---|
| JPS57182990A (en) | 1982-11-11 |
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