JPS61230282A - Spark plug - Google Patents

Abstract

(57)【要約】本公報は電子出願前の出願データであるた
め要約のデータは記録されません。(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

【発明の詳細な説明】 （産業上の利用分野） 本発明は自動車などの内燃機関に用いて耐消耗性に優れ
た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 a spark plug that is used in internal combustion engines such as automobiles and has excellent wear resistance.

（従来の技術） 従来よりスパークプラグの中心電極及び接地電極の火花
放電部に耐熱耐消耗性に優れｔＰｔ合金例えばＰ　ｔ−
Ｉ　ｒ　、　Ｐ　ｔ−Ｒｈ　、　Ｐ　ｔ−Ｎｉ　。(Prior Art) Conventionally, the spark discharge part of the center electrode and ground electrode of a spark plug is made of tPt alloy, such as Pt- alloy, which has excellent heat and wear resistance.
Ir, Pt-Rh, Pt-Ni.

Ｐｔ−Ｐｄ＝Ｐｔ−Ｒｕ等の貴金属材から成る薄板（チ
ップ）ないしは貴金属塊を電気溶接等で接合し、スパー
クプラグの長寿命化を図ることが知られている。このう
ち、特にＰｔ−Ｎｉ系合金はＮｉ系合金、母材金属との
線膨張係数が近く、燃焼がヌの繰返し加熱、冷却により
生ずる熱応力が引起す白金チップ、白金塊の母材からの
剥離が軽減され、スパークプラグ用白金電極として適し
穴材料である。It is known to extend the life of a spark plug by joining thin plates (chips) or precious metal blocks made of noble metal materials such as Pt-Pd=Pt-Ru by electric welding or the like. Among these, the Pt-Ni alloy has a coefficient of linear expansion close to that of the Ni-based alloy and the base metal, and thermal stress caused by repeated heating and cooling without combustion causes platinum chips and platinum ingots from the base metal. It reduces peeling and is a suitable hole material for platinum electrodes for spark plugs.

（発明が解決しようとする問題点） しかし、このＰｔ−Ｎｉ系合金は使用温度が１０００℃
以上と非常に高くなると結晶粒の粗大化現象が容易に生
じ、繰返し冷熱サイクルで生ずる熱歪による結晶粒界の
脆化及び粒界割れが起り侵蝕されるという問題があり、
甚しい場合には貴粗大化抑制が必要で６る。(Problem to be solved by the invention) However, this Pt-Ni alloy has a working temperature of 1000°C.
If the temperature is extremely high, the coarsening of crystal grains will easily occur, and the thermal strain caused by repeated cooling and heating cycles will cause grain boundary embrittlement and grain boundary cracking, leading to erosion.
In severe cases, it is necessary to suppress the growth of nobles.

（問題点を解決するための手段〕 本発明はＰｔ−Ｎｉ系合金における高温時の強度を向上
し結晶粒粗大を抑制して結晶粒の微細化を保ち、粒界割
れの間Ｎｔ−解決し１つとするものであって、Ｎｉ系合
金を母材金属とする電極の火花放電部又は母材と接合す
る中間層としてＰｔ−Ｎｉ系合金を用い、その組成をＮ
ｉ５〜４０重量％ｓｃａ＊Ｂａ＊Ｔｉ　ｅＮｂｅＭｇか
ら成る元素の１種を０．０５〜１重竜％と残部Ｐｔとす
ることにより、耐久性に優れてブラダの長寿命化をなし
たスパークプラグを提供しようとするものである。(Means for Solving the Problems) The present invention improves the strength of Pt-Ni alloys at high temperatures, suppresses grain coarsening, maintains grain refinement, and resolves Nt-Ni during intergranular cracking. A Pt-Ni alloy is used as the spark discharge part of an electrode having a Ni alloy as a base metal or as an intermediate layer to be bonded to the base metal, and its composition is N.
A spark plug with excellent durability and a long bladder life has been created by adding one of the elements consisting of i5 to 40% by weight sca*Ba*Ti eNbeMg to 0.05 to 1% by weight and the balance being Pt. This is what we are trying to provide.

ま九本発明は上記Ｐｔ−Ｎｉ系合金がＮｉ５〜４０重１
％＊ＣａｔＢａｔＴｉ　ｅＮｂｅＭｇから成るから合金
材を使用することにより、同様に耐久性に優れてブラダ
の長寿命化をなしたスパークプラグを提供しようとする
ものである。9. The present invention is characterized in that the above Pt-Ni alloy contains 5 to 40% Ni.
By using an alloy material consisting of %*CatBatTi eNbeMg, the present invention aims to provide a spark plug which is also excellent in durability and has a long bladder life.

（実施例） 以下本発明全具体的に詳述する。(Example) The present invention will be described in detail below.

第１図及びｇ！ｇ２図は本発明の代表的なスパークプラ
グの発火部の要部断面図であり、図中１は機関取付ねじ
を具え几主体金具、２は前記主体金具１の内腔内に封入
固定された高アルミナ磁器等から成る絶縁体、３は前記
絶縁体２の軸孔内にその先端面より突出して封着され比
内部にＣｕ芯を配したＮｉ系合金、例えばＮｉ−８ｉ−
Ｃｒ−ＡＩ合金ＩＮＩ　　Ｃｒ　　Ｆｅ合金（インコネ
ル）などの母材金属から成る中心電極、４は前記中心電
極３の先端８ａに接合されｔ火花放電部でＰｔ−Ｎｉ系
合金材で構成されている。５に前記主体金具ｌの端面１
ａ！ｖ突設さａ友前記中心電極母材と同様なＮｉ系合金
の母材金属から成る接地電極、６は前記接地電極５の火
花放電部で同様にＰｔ−Ｎｉ系合金材で構成されており
、この火花放電部６は前記中心電極３の火花放電部４と
の間に火花ギヤラグ７を形成し几スパークブッダである
。Figure 1 and g! Figure g2 is a cross-sectional view of the main parts of the ignition part of a typical spark plug of the present invention, in which 1 is a metal shell equipped with an engine mounting screw, and 2 is a metal shell sealed and fixed in the inner cavity of the metal shell 1. An insulator 3 made of high alumina porcelain or the like is sealed in a shaft hole of the insulator 2 so as to protrude from its tip surface, and is made of a Ni-based alloy such as Ni-8i-
A center electrode 4 made of a base metal such as Cr-AI alloy INI CrFe alloy (Inconel) is connected to the tip 8a of the center electrode 3 and is made of a Pt-Ni alloy material at a spark discharge portion. 5, the end surface 1 of the metal shell l
a! A ground electrode 6 is made of a Ni-based alloy base metal similar to the center electrode base material, and 6 is a spark discharge part of the ground electrode 5, which is also made of a Pt-Ni alloy material. This spark discharge part 6 forms a spark gear lug 7 between the center electrode 3 and the spark discharge part 4, and is a spark Buddha.

また本発明は第２図に示すように、中心電極８及び接地
電極５の夫々の火花放電部８及び９を耐消耗性に優れ２
Ｐｔ−Ｉｒ（２０％Ｉｒ）、Ｐｔ−ＰｄｌＯ％Ｐｄ）等
で形成し、夫々の母材との接合する中間層１０及び１１
にＰｔ−Ｎｉ系合金で構成されたスパークプラグである
。なおこれら実施例には貴金属材は中心電極と接地電極
の両者に形成されているが、郷関の特性、電極温度及び
電源極性に応じていずれか一方のみに貴金属材を、又は
いずれが一方にＰｔ−Ｎｉ系合金材と他方に耐消耗性に
優れたＰｔ合合金材総組せ使用することができる。Furthermore, as shown in FIG.
Intermediate layers 10 and 11 formed of Pt-Ir (20% Ir), Pt-PdlO%Pd, etc., and bonded to the respective base materials.
This spark plug is made of a Pt-Ni alloy. In these examples, the noble metal material is formed on both the center electrode and the ground electrode, but depending on the characteristics of the electrode, the electrode temperature, and the power supply polarity, the noble metal material may be formed only on one of them, or Pt may be formed on either one of the electrodes. -Ni alloy material and Pt alloy material with excellent wear resistance can be used in combination.

母材金属電極の火花放電部４．６又は母材金属との接合
面である中間Ｎ１１０，１１に用いる本発明のＰ　ｔ　
−Ｎ　ｉ系合金材としては、Ｎｉ５〜４０重量％ｅｃａ
＊ＢａｅＴｔ　ｅＮｂｅＭｇから成る元素の１種ｔ−０
，０５〜１．０重量％と残部Ｐｔから成る合金管使用す
るか、又はＮｉ５〜４０重′１に％。Pt of the present invention used for the spark discharge part 4.6 of the base metal electrode or the intermediate N110, 11 which is the joint surface with the base metal
-Ni-based alloy material includes Ni5 to 40% by weight eca
*One type of element t-0 consisting of BaeTt eNbeMg
, 05-1.0% by weight and the balance Pt, or Ni 5-40% by weight'1.

Ｃａ＊ＢａｔＴｉ＊Ｎｂ＊Ｍｇから成る元素の１種とＲ
ｅ＊Ｙ＋Ｚｒ＊ＨｆｔＡｌから硯る元素の１種との和が
０．０５〜１．０重量％と残部Ｐｔから成る合金を使用
することにより、高温時の結晶粒粗大化抑制、粒界割れ
防止に有効であることｔ−見出したものである。One of the elements consisting of Ca*BatTi*Nb*Mg and R
By using an alloy consisting of a sum of 0.05 to 1.0% by weight of one of the elements obtained from e*Y+Zr*HftAl and the balance Pt, grain coarsening at high temperatures is suppressed and intergranular cracking is prevented. This is what we found to be effective.

本発明において、Ｐｔ−Ｎｉ系合金のＮｉの添加量を５
〜４０重量％に限定し念のは５重量％以下ではＮｉ系合
金母材との熱膨張差が大きく、４０重ｔ％以上では熱膨
張差が小さぐ接着性が良好となるが、Ｎｉ増加によって
合金自体の耐酸化性が著しく劣化するためである。また
結晶粒粗大化抑制としてのＣａｔＢａｔＴｉ　ｔＮｂｐ
Ｍｇの元素の１種Ｔｈ０．０５〜１．０重量％又は前記
Ｃａ　ｅ　Ｂ　ａ　ｅＴｉｔＮｂ、Ｍｇの元素の１種と
ＲｅｔＹｔＺｒ＊Ｈｆ、ＡＩの元素の１種とを複合して
０．０５〜１．０重量％に添加量を規定し九のは０．０
５重量％より少ないと十分な結晶粒微細化効果が得られ
なく、１．０重世％より多いと極端に加工性（伸線、圧
延性）が悪化し、製品の安定したものが得られなくなる
ｔめである。In the present invention, the amount of Ni added to the Pt-Ni alloy is 5
It is limited to ~40% by weight, and it is important to note that if it is less than 5% by weight, the difference in thermal expansion with the Ni-based alloy base material will be large, and if it is more than 40% by weight, the difference in thermal expansion will be small and the adhesion will be good, but the Ni increase This is because the oxidation resistance of the alloy itself is significantly deteriorated. In addition, CatBatTi tNbp as a grain coarsening control
Th0.05 to 1.0% by weight of one kind of Mg element or 0.05 to 1% by composite of one kind of element of Ca e Ba e TitNb, Mg and one kind of element of RetYtZr*Hf, AI The amount added is specified as .0% by weight, and the ninth is 0.0.
If it is less than 5% by weight, a sufficient grain refining effect cannot be obtained, and if it is more than 1.0% by weight, workability (wire drawability, rollability) deteriorates extremely, making it difficult to obtain a stable product. It's about to disappear.

（実施例１） 表１に示すようにＰｔ−Ｎｉ合金にＣａ　ｅ　Ｂ　ａ　
ｅＴｉ＃Ｎｂ＃Ｍｇの元素を単独に添加した成分の合金
材及び表２に示すようにＣａ＊Ｂａ＊Ｔｉ＊Ｎｂ＊Ｍｇ
の元素の１種とＲｅｔＹ＊Ｚｒ＊ＨｆｐＡ１の元素の１
種とを複合添加した成分の合金材を用い、これらを直径
２．ＯＨφのＮｉ系合金（インコネル６００）の母材電
極の先端凹部に夫々直径１履φ×厚さ９．４　Ｍｌｌの
、に１〜、に２５の試料を抵抗溶接にて接合したもので
性能を比較した。なお性能評価として大気中１１００℃
×１０時間の熱処理後の結晶粒度Ｎｏ（オーステナイト
粒度）とバーナーによる１１００”ＯＸ１分加熱と放冷
１分（約２００℃まで）ｘａｏｏｏサイクル繰返し後の
粒界亀裂によって比較した。(Example 1) As shown in Table 1, Ca e Ba was added to the Pt-Ni alloy.
As shown in Table 2, alloy materials containing elements such as eTi#Nb#Mg and Ca*Ba*Ti*Nb*Mg
One of the elements of and one of the elements of RetY*Zr*HfpA1
Using an alloy material with a composite addition of seeds, these are made into a diameter of 2. The performance was measured by resistance welding 1 to 25 specimens, each with a diameter of 1 mm and a thickness of 9.4 Mll, to the tip recess of a base metal electrode made of OHφ Ni-based alloy (Inconel 600). compared. In addition, as a performance evaluation, 1100℃ in the atmosphere
The grain size No. (austenite grain size) after 10 hours of heat treatment was compared with grain boundary cracks after repeating the xaooo cycle of heating at 1100"OX for 1 minute with a burner and cooling for 1 minute (up to about 200° C.).

表　　　１ 表　　　２ テスト結果は゛表１、表２に示すようにＰｔ−２ＯＮｉ
合金の、に１は高温時の結晶粒の粗大化が容易に生じ、
８０００サイクルで粒界割れによる大きな亀裂となっｔ
ｏこれに対して本発明のＰｔ−Ｎｉ合金にＣａｔＢａｔ
Ｔｉ　ｅＮｂｅＭｇの元素を単独添加した洗２〜．に１
１及び前記元素とＲｅ＝Ｙ−Ｚｒ＊Ｈｆ、Ａｌの元素と
を複合添加しｆｃ、Ｋ　１２〜２５の試料はいずれも結
晶粒の粗大化が少なく微細化を有し、冷熱３０００サイ
クルテスト後においても、に２と、に１２の試料に微小
亀裂が認められたが他のものは全く異常は認められず良
好であった。Table 1 Table 2 The test results are as shown in Tables 1 and 2.
In alloy 1, the crystal grains easily coarsen at high temperatures;
After 8000 cycles, a large crack developed due to intergranular cracking.
o In contrast, CatBat is added to the Pt-Ni alloy of the present invention.
Washing 2~ in which Ti eNbeMg element was added alone. to 1
1 and the above elements and the elements of Re=Y-Zr*Hf, Al were added together, fc, K 12 to 25. All the samples had less coarsening of crystal grains and finer grains, and after 3000 cycles of cold and hot cycles test. Also, microcracks were observed in samples No. 2 and No. 12, but no abnormality was observed in the other specimens, which were in good condition.

なお本発明スパークプラグは電極の火花放電部の貴金属
材の形態が第１図及び第２図の薄板の実施例だけに限定
されるものでなく、貴金属材は第３図に示すように中心
電極３又は接地電極５の先端に貴金属塊１４，１６（棒
状片〕を固着し几スパークプラグ、或は第４図に示すよ
うに中心電極３の先端周側１７又は先端周縁に貴金属材
を配設し、これら先端周側又は先端周縁との間に対向す
る接地電極５を設けたスパークプラグ又はセミ沿面スパ
ークグラブなど種々な電極形状のスパークプラグに適用
することができる。In addition, in the spark plug of the present invention, the form of the noble metal material in the spark discharge part of the electrode is not limited to the thin plate embodiments shown in FIGS. 1 and 2. 3 or ground electrode 5 with precious metal lumps 14, 16 (rod-shaped pieces) fixed to the tip thereof, or as shown in FIG. However, the present invention can be applied to spark plugs with various electrode shapes, such as spark plugs or semi-creeping spark plugs in which a ground electrode 5 is provided facing the tip periphery side or between the tip periphery.

（発明の効果〕 以上述べた如く、本発明スパークプラグは火花放電部又
は母材電極との中間層に用いるＰｔ−Ｎｉ合金に第三元
素としてＣａｅＢａｔＴｉｔＮｂ＊Ｍｇの単独又はこれ
ら元素とＲｅｔＹｔＺｒ＊　　　’Ｈｆ、Ａｌとを複合
して０．０５〜１．０重量％添加した合金材全使用する
ことに工９、従来のＮｉ系合金母材電極との良好な接着
性を保持し、且つ高温時の結晶粒粗大化抑制効果を著し
く高める几め冷熱サイクルにおいても耐久性に優れて安
定し九品質の長寿命プラグを提供することができる。(Effects of the Invention) As described above, the spark plug of the present invention contains CaeBatTitNb*Mg alone or in combination with these elements and RetYtZr* 'Hf as a third element in the Pt-Ni alloy used for the spark discharge part or the intermediate layer with the base material electrode. By using the alloy material containing 0.05 to 1.0% by weight of aluminum, it maintains good adhesion with the conventional Ni-based alloy base electrode and is highly resistant to high temperature conditions. It is possible to provide a long-life plug with excellent durability and stability even in a strict cooling/heating cycle that significantly increases the effect of suppressing crystal grain coarsening.

【図面の簡単な説明】[Brief explanation of drawings]

＠１図〜第４図は本発明の実施例を示すスパークプラグ
の発火部の要部拡大断面図である。 ８・・・中心電極　５・・・接地電極　４，６，８，９
．１４，１６．１７・・・火花放電部　１０．１１・・
・中間層 第１図 ａ　　　１ 第２図 ａ　　　１1 to 4 are enlarged sectional views of the main parts of the ignition part of a spark plug showing an embodiment of the present invention. 8... Center electrode 5... Ground electrode 4, 6, 8, 9
．． 14,16.17...Spark discharge part 10.11...
・Middle layer Figure 1 a 1 Figure 2 a 1

Claims (2)

【特許請求の範囲】[Claims] （１）Ｎｉ系合金を母材金属とする中心電極及び接地電
極の少くとも一方の火花放電部としてＰｔ−Ｎｉ系合金
を固着したスパークプラグ又は前記火花放電部として耐
消耗性に優れたＰｔ合金を使用すると共にこのＰｔ合金
と母材金属との間にＰｔ−Ｎｉ系合金から成る中間層を
配置したスパークプラグにおいて、前記Ｐｔ−Ｎｉ系合
金としてＮｉ５〜４０重量％、Ｃａ、Ｂａ、Ｔｉ、Ｎｂ
、Ｍｇから成る元素の１種を０．０５〜１．０重量％と
残部Ｐｔから成る合金材を使用することを特徴とするス
パークプラグ。(1) A spark plug in which a Pt-Ni alloy is fixed as the spark discharge part of at least one of the center electrode and the ground electrode, whose base metal is a Ni-based alloy, or a Pt alloy with excellent wear resistance as the spark discharge part. In a spark plug in which an intermediate layer made of a Pt-Ni alloy is arranged between the Pt alloy and the base metal, the Pt-Ni alloy contains 5 to 40% by weight of Ni, Ca, Ba, Ti, Nb
A spark plug characterized in that it uses an alloy material consisting of 0.05 to 1.0% by weight of one of the elements consisting of Mg and the balance Pt. （２）Ｎｉ系合金を母材金属とする中心電極及び接地電
極の少なくとも一方の火花放電部としてＰｔ−Ｎｉ系合
金を固着したスパークプラグ又は前記火花放電部として
耐消耗性に優れたＰｔ合金を使用すると共にこのＰｔ合
金と母材金属との間にＰｔ−Ｎｉ系合金から成る中間層
を配置したスパークプラグにおいて、前記Ｐｔ−Ｎｉ系
合金としてＮｉ５〜４０重量％、Ｃａ、Ｂａ、Ｔｉ、Ｎ
ｂ、Ｍｇから成る元素の１種とＲｅ、Ｙ、Ｚｒ、Ｈｆ、
Ａｌから成る元素の１種との和が０．０５〜１．０重量
％と残部Ｐｔから成る合金材を使用することを特徴とす
るスパークプラグ。(2) A spark plug in which a Pt-Ni alloy is fixed as the spark discharge part of at least one of the center electrode and the ground electrode, which have a Ni-based alloy as the base metal, or a Pt alloy with excellent wear resistance is used as the spark discharge part. In a spark plug in which an intermediate layer made of a Pt-Ni alloy is arranged between the Pt alloy and the base metal, the Pt-Ni alloy contains 5 to 40% by weight of Ni, Ca, Ba, Ti, N.
b, one type of element consisting of Mg and Re, Y, Zr, Hf,
A spark plug characterized in that an alloy material is used in which the sum of 0.05 to 1.0% by weight of one type of element consisting of Al and the balance is Pt.