JPH0966370A - Electrode for resistance spot welding to aluminum material to be welded and resistance spot welding method - Google Patents
Electrode for resistance spot welding to aluminum material to be welded and resistance spot welding methodInfo
- Publication number
- JPH0966370A JPH0966370A JP7225572A JP22557295A JPH0966370A JP H0966370 A JPH0966370 A JP H0966370A JP 7225572 A JP7225572 A JP 7225572A JP 22557295 A JP22557295 A JP 22557295A JP H0966370 A JPH0966370 A JP H0966370A
- Authority
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- Prior art keywords
- electrode
- welded
- tmm
- resistance spot
- spot welding
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Abstract
Description
【0001】[0001]
【発明の属する技術分野】本発明は、アルミニウム系被
溶接材料の抵抗スポット溶接用電極および抵抗スポット
溶接方法に係わり、特に、アルミニウム系被溶接材料の
スポットの溶接に際しての連続打点性(電極寿命)を向
上させる技術に関するものである。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electrode for resistance spot welding of an aluminum-based material to be welded and a resistance spot welding method, and more particularly, to a continuous spotting property (electrode life) when welding a spot of an aluminum-based material to be welded. It is related to the technology to improve.
【0002】[0002]
【従来の技術】従来のアルミニウム系被溶接材料の抵抗
スポット溶接用電極および抵抗スポット溶接方法として
は、以下に示すようなものがある。2. Description of the Related Art The following are conventional resistance spot welding electrodes and resistance spot welding methods for aluminum-based materials to be welded.
【0003】従来例1:アルミニウム系被溶接材料の抵
抗スポット溶接用電極としては、実用上はもっぱら鋼板
と同様のクロム銅(Cu−Cr)等のRWMAクラス2
電極が用いられている。Conventional Example 1: As an electrode for resistance spot welding of an aluminum-based material to be welded, RWMA class 2 such as chrome copper (Cu-Cr) which is practically the same as a steel plate is practically used.
Electrodes are used.
【0004】従来例2:電極の芯部と外周部とで2層構
造とした複合構造電極を用い、電気伝導度やビッカース
硬さ、融点等を芯部と外周部とでそれぞれ異なった特性
とした技術が、例えば、特開平4−356377号公
報、特開平5−318140号公報等で公開されてい
る。Conventional Example 2: A composite structure electrode having a two-layer structure having a core portion and an outer peripheral portion of the electrode is used, and electric conductivity, Vickers hardness, melting point, etc. are different between the core portion and the outer peripheral portion. Such techniques are disclosed in, for example, Japanese Patent Laid-Open Nos. 4-356377 and 5-318140.
【0005】従来例3:単一材料の電極としては、例え
ば、特開平6−210461号公報のように、電気伝導
度を92IACS%以上とした高導電材料を用い、か
つ、ビッカース硬さを特定範囲とした技術が公開されて
いる。Conventional Example 3: As an electrode made of a single material, for example, as in Japanese Patent Laid-Open No. 6-210461, a highly conductive material having an electric conductivity of 92 IACS% or more is used, and the Vickers hardness is specified. The range of technologies has been published.
【0006】[0006]
【発明が解決しようとする課題】しかしながら、このよ
うな従来のアルミニウム系被溶接材料の抵抗スポット溶
接用電極および抵抗スポット溶接方法にあっては、下記
に示すような解決すべき課題があった。However, the conventional resistance spot welding electrodes and resistance spot welding methods for aluminum-based materials to be welded have the following problems to be solved.
【0007】従来例1:従来例1のクロム銅等のRWM
Aクラス2電極にあっては、本来は鋼板のスポット溶接
用として永年用いられてきた材料であり、材料の軟化温
度を高めるために、銅に添加元素を加えていることか
ら、電気伝導度は低くなり、75〜85IACS%程度
となる。このため、通電中に電極先端と被溶接材料との
間で発熱し、電極先端にアルミニウムと銅の合金層を生
成しやすい。そして、こうして生成された電極先端の合
金層が次の溶接で被溶接材料側にくっついて持って行か
れ、この繰り返しによって電極先端には皿状のくぼみが
発生し、ピックアップ劣化と呼ばれる劣化形態を示す
(図2(C)参照)。)。このようにして、電極先端が
劣化して接触径が広がっていくと、溶接部の外観品質が
劣化することになると共に、電流密度が低下して電極寿
命に至る。Conventional Example 1: RWM such as chromium copper of Conventional Example 1
The A class 2 electrode is a material that has been used for many years for spot welding of steel sheets, and since it has an additive element added to copper in order to increase the softening temperature of the material, its electrical conductivity is It becomes low, about 75 to 85 IACS%. Therefore, heat is generated between the electrode tip and the material to be welded during energization, and an alloy layer of aluminum and copper is easily generated at the electrode tip. Then, the alloy layer at the electrode tip generated in this way is brought to the material to be welded side by side in the next welding, and by repeating this, a dish-shaped recess is generated at the electrode tip, which causes a deterioration form called pickup deterioration. This is shown (see FIG. 2C). ). In this way, when the tip of the electrode deteriorates and the contact diameter expands, the appearance quality of the welded portion deteriorates, and the current density decreases, leading to the life of the electrode.
【0008】以上の理由から、アルミニウム系被溶接材
料の抵抗スポット溶接における一般的なRWMAクラス
2電極の連続打点性は、鋼板の抵抗スポット溶接に比べ
て著しく低下し、鋼板の1/10〜1/20程度とな
る。したがって、頻繁な電極ドレッシングを行って常に
電極先端の形状を整えたり、付着物を除去して電流密度
を一定に保ったりする必要があるため、アルミニウム合
金部品の溶接による生産性は極めて低いという問題点が
あった。したがって、このような問題点を解決すること
が課題としてあった。For the above reason, the continuous spotting property of a general RWMA class 2 electrode in resistance spot welding of aluminum-based materials to be welded is remarkably lower than that of resistance spot welding of steel sheet, and is 1/10 to 1/10 of that of steel sheet. It will be about / 20. Therefore, it is necessary to perform frequent electrode dressing to constantly shape the electrode tip, and to remove deposits to keep the current density constant, resulting in extremely low productivity of welding aluminum alloy parts. There was a point. Therefore, there is a problem to solve such a problem.
【0009】従来例2:従来例2に示すような複合構造
電極にあっては、芯部に用いられる材料は一般的に硬度
が高く、電気伝導度も従来のRWMAクラス2電極と同
等であるため、従来例1のクロム銅の場合と同様に電極
先端の発熱によりアルミニウムと銅との合金層を生成し
やすく、このため従来例1と同様にピックアップ劣化す
るため、連続打点性に大幅な向上は望めない割には、複
合構造であるために電極のコストも上昇するという問題
点があった。したがって、このような問題点を解決する
ことが課題としてあった。Conventional Example 2: In the composite structure electrode as shown in Conventional Example 2, the material used for the core is generally high in hardness and the electric conductivity is the same as that of the conventional RWMA class 2 electrode. For this reason, as in the case of the chromium copper of Conventional Example 1, it is easy to generate an alloy layer of aluminum and copper due to heat generation at the electrode tip. Therefore, as in Conventional Example 1, pickup deterioration occurs, and continuous dot performance is greatly improved. Although it cannot be expected, there is a problem that the cost of the electrode increases because of the composite structure. Therefore, there is a problem to solve such a problem.
【0010】従来例3:従来例3で示したような、比較
的高い電気伝導度をもった電極材料を用いた場合は、従
来例1や従来例2に示したようなアルミニウムと銅との
合金層を形成しにくいので、アルミニウム系被溶接材料
の抵抗スポット溶接での連続打点性はやや向上する。し
かしながら、連続打点試験により性能を確認した結果、
若干の効果が認められたものの、高温での軟化温度を高
めた、つまり、軟化温度を約400℃とした材料特性を
有しているため、打点数と共に電極先端の接触径が広が
るのは避けられず、結局、電流密度の低下をきたし、鋼
板並みの連続打点性能を得るまでは至らないという問題
点があった。したがって、このような問題点を解決する
ことが課題としてあった。Conventional Example 3: When an electrode material having a relatively high electric conductivity as shown in Conventional Example 3 is used, aluminum and copper as shown in Conventional Example 1 and Conventional Example 2 are used. Since it is difficult to form the alloy layer, the continuous spotting property in resistance spot welding of the aluminum-based material to be welded is slightly improved. However, as a result of confirming the performance by the continuous dot test,
Although a slight effect was observed, the softening temperature at high temperature was raised, that is, the softening temperature was about 400 ° C, so the material characteristics were set so that the contact diameter of the electrode tip should not spread with the number of dots. However, there was a problem in that the current density eventually decreased, and it was not possible to achieve continuous spotting performance comparable to that of steel sheets. Therefore, there is a problem to solve such a problem.
【0011】[0011]
【発明の目的】本発明は、このような従来の課題にかん
がみてなされたものであって、アルミニウム系被溶接材
料の抵抗スポット溶接用電極および抵抗スポット溶接方
法において、電極材料の電気伝導度と、高温での被溶接
材料に対する硬度特性を最適化するとともに、電極先端
の形状を特定の形状とすることにより、連続打点におい
て電極先端の接触径を一定に保つ、つまり、溶接時の電
流密度を一定に保つための突起を形成維持させることに
よって、鋼板並みの連続打点性と溶接部の良好なる外観
品質が得られるようにし、アルミニウム系被溶接材料の
抵抗スポット溶接に際して従来のような電極寿命が短く
かつまた溶接部の外観品質が低下するという問題点を解
決することを目的としている。SUMMARY OF THE INVENTION The present invention has been conceived in view of the above-mentioned conventional problems, and in an electrode for resistance spot welding of an aluminum-based material to be welded and a resistance spot welding method, the electric conductivity of the electrode material is By optimizing the hardness characteristics for the material to be welded at high temperature and by making the shape of the electrode tip a specific shape, the contact diameter of the electrode tip is kept constant at continuous welding points, that is, the current density during welding is By forming and maintaining the protrusions to keep it constant, it is possible to obtain continuous spotting properties similar to steel plates and good appearance quality of the welded part, and the conventional electrode life is maintained when resistance spot welding aluminum-based materials to be welded. It is intended to solve the problem that the appearance quality of the welded portion is short and also deteriorates.
【0012】[0012]
【課題を解決するための手段】本発明に係わるアルミニ
ウム系被溶接材料の抵抗スポット溶接用電極は、溶接通
電中の電極先端部近傍の温度範囲において、電極に、被
溶接材料であるアルミニウム合金の軟化特性にあわせた
高温硬度特性、つまり、特定温度域における軟化特性を
持たせるようにしたことを特徴としているものであり、
より具体的には、請求項1に記載しているように、アル
ミニウム系被溶接材料の抵抗スポット溶接に用いる電極
において、電極の電気伝導度が97IACS%以上で、
かつ、200℃以下ではビッカース硬さHv80以上、
400℃以上ではビッカース硬さHv30以下となるよ
うに、200℃から400℃の間でビッカース硬さがH
v80以上からHv30以下に軟化する高温硬度特性を
有する材料を用いてなる構成としたことを特徴としてい
る。An electrode for resistance spot welding of an aluminum-based material to be welded according to the present invention has a resistance spot welding electrode of an aluminum alloy, which is a material to be welded, to the electrode in a temperature range near the tip of the electrode during welding. It is characterized by having a high temperature hardness characteristic matched to the softening characteristic, that is, having a softening characteristic in a specific temperature range.
More specifically, as described in claim 1, in an electrode used for resistance spot welding of an aluminum-based material to be welded, the electric conductivity of the electrode is 97 IACS% or more,
And, at 200 ° C or lower, Vickers hardness Hv80 or higher,
The Vickers hardness is Hv30 or less at 400 ° C or higher, and the Vickers hardness is H between 200 ° C and 400 ° C.
It is characterized by using a material having a high temperature hardness characteristic that softens from v80 or more to Hv30 or less.
【0013】この場合、電気伝導度の単位において用い
ているIACSとは、International A
nnealed Copper Standardの略
であり、IACS%とは、標準焼なましCu材に対する
電気伝導率の百分率(%)である。In this case, IACS used in the unit of electrical conductivity is International A
It is an abbreviation for "nnealed Copper Standard", and IACS% is a percentage (%) of electric conductivity with respect to a standard annealed Cu material.
【0014】そして、本発明に係わるアルミニウム系被
溶接材料の抵抗スポット溶接用電極の実施態様において
は、請求項2に記載しているように、電極先端の形状が
電極先端にR8mm〜R40mmの曲率半径をもつR形
であって、かつ、被溶接材料の薄板側の板厚をtmmと
したときに、そのR形状の部分が少なくとも直径で6√
tmm以上確保されているものとしたり、請求項3に記
載しているように、電極先端の形状が被溶接材料の薄板
側の板厚をtmmとしたときに、電極先端に直径4√t
mm〜6√tmmの平面部を有し、かつ、その外周部は
曲率半径がR8mm〜R40mmのR形であるものとし
たり、請求項4に記載しているように、電極先端の形状
が電極先端にR8mm〜R40mmの曲率半径をもつR
形であって、かつ、被溶接材料の薄板側の板厚をtmm
としたときに、そのR形状の先端部の直径が4√tmm
〜6√tmmの範囲にのみ、曲率半径がその電極の前記
曲率半径よりも大きい別の曲率半径を有した少なくとも
二つ以上の複合球面ないしは複合曲面で構成される形状
を有するものとしたり、請求項5に記載しているよう
に、電極先端の形状が被溶接材料の薄板側の板厚をtm
mとしたときに、電極先端に直径4√tmm〜6√tm
mの平面部を有し、かつ、その外周部は電極の軸芯との
直交軸に対し5°〜30°の角度をもつ略テーパ形状を
有するものとしたり、請求項6に記載しているように、
電極先端の形状が被溶接材料の薄板側の板厚をtmmと
したときに、電極先端に直径4√tmm〜6√tmmの
範囲にのみ、適宜な曲率半径をもつ球面部を有し、か
つ、その外周部は電極の軸芯との直交軸に対し5°〜3
0°の角度をもつ略テーパ形状を有するものとしたりす
ることができる。In an embodiment of the electrode for resistance spot welding of an aluminum-based material to be welded according to the present invention, as described in claim 2, the shape of the electrode tip has a curvature of R8 mm to R40 mm at the electrode tip. When it is R-shaped with a radius and the thickness of the thin plate side of the material to be welded is tmm, the R-shaped part is at least 6√ in diameter.
When the thickness of the electrode tip is tmm or more, or when the shape of the electrode tip is the thickness of the thin plate side of the material to be welded is tmm, the diameter of the electrode tip is 4√t.
It has a flat part of mm to 6√tmm, and the outer peripheral part thereof has an R shape with a radius of curvature of R8 mm to R40 mm, or the electrode tip has a shape as described in claim 4. R with a radius of curvature of R8mm to R40mm at the tip
The thickness of the material to be welded on the thin plate side is tmm
And the diameter of the R-shaped tip is 4√tmm
A shape composed of at least two or more compound spherical surfaces or compound curved surfaces having another radius of curvature larger than the radius of curvature of the electrode only in the range of up to 6√tmm; As described in Item 5, the shape of the electrode tip is tm when the thickness of the thin plate of the material to be welded is tm.
When m, the diameter of the electrode tip is 4√tmm to 6√tm
It has a flat part of m, and its outer peripheral part has a substantially taper shape having an angle of 5 ° to 30 ° with respect to an axis orthogonal to the axis of the electrode. like,
When the shape of the electrode tip is tmm, and the thickness of the thin plate side of the material to be welded is tmm, the electrode tip has a spherical portion having an appropriate radius of curvature only in the range of diameter 4√tmm to 6√tmm, and , Its outer periphery is 5 ° to 3 with respect to the axis orthogonal to the axis of the electrode.
For example, it may have a substantially tapered shape with an angle of 0 °.
【0015】また、同じく本発明に係わるアルミニウム
系被溶接材料の抵抗スポット溶接用電極の実施態様にお
いては、請求項7に記載しているように、電極先端の形
状が被溶接材料の薄板側の板厚をtmmとしたときに、
電極先端に直径4√tmm〜6√tmmで、高さ0.1
tmm〜0.3tmmとなる突起を設け、かつ、前記突
起の外周部には前記突起の外壁から全周にわたって少な
くとも1mm以上の平坦部を形成した形状としたものと
することができ、この場合、請求項8に記載しているよ
うに、前記突起の角部または外壁部と、平坦部とを適宜
な曲率半径をもつ曲面でつないだ形状としたり、請求項
9に記載しているように、前記突起の先端形状が平面で
あるものとしたり、請求項10に記載しているように、
前記突起の先端形状が適宜な曲率半径を有した球面であ
るものとしたりすることができる。Also, in the embodiment of the electrode for resistance spot welding of the aluminum-based material to be welded according to the present invention, as described in claim 7, the shape of the electrode tip is the thin plate side of the material to be welded. When the plate thickness is tmm,
Diameter 4√tmm ~ 6√tmm at electrode tip, height 0.1
A protrusion having a size of tmm to 0.3 tmm may be provided, and a flat portion of at least 1 mm or more may be formed on the outer peripheral portion of the protrusion from the outer wall of the protrusion, and in this case, As described in claim 8, a corner portion or an outer wall portion of the protrusion and a flat portion are connected by a curved surface having an appropriate radius of curvature, or as described in claim 9, The tip shape of the projection is flat, or as described in claim 10,
The tip shape of the protrusion may be a spherical surface having an appropriate radius of curvature.
【0016】また、本発明に係わるアルミニウム系被溶
接材料の抵抗スポット溶接方法は、請求項11に記載し
ているように、アルミニウム系被溶接材料を抵抗スポッ
ト溶接するに際し、電極の電気伝導度が97IACS%
以上で、かつ、電極と被溶接材料との硬度差がビッカー
ス硬さにおいて、200℃以下ではHv20以上であ
り、250℃〜400℃の温度範囲の間ではHv15以
下となるような電極と被溶接材料とを用いて溶接を行う
ようにしたことを特徴としている。According to the resistance spot welding method for an aluminum-based material to be welded according to the present invention, when the aluminum-based material to be welded is resistance spot-welded, the electrical conductivity of the electrode is reduced. 97IACS%
Above, and the electrode and the welded material such that the hardness difference between the electrode and the material to be welded is Hv20 or more at 200 ° C. or less and Hv15 or less at a temperature range of 250 ° C. to 400 ° C. in Vickers hardness. The feature is that welding is performed using the material.
【0017】そして、本発明に係わるアルミニウム系被
溶接材料の抵抗スポット溶接用電極および抵抗スポット
溶接方法の実施態様においては、請求項12に記載して
いるように、電極の材質がタフピッチ銅であるものとし
たり、請求項13に記載しているように、電極の材質が
無酸素銅であるものとしたりすることができる。In an embodiment of the resistance spot welding electrode and the resistance spot welding method for an aluminum-based material to be welded according to the present invention, as described in claim 12, the material of the electrode is tough pitch copper. Alternatively, as described in claim 13, the material of the electrode may be oxygen-free copper.
【0018】[0018]
【発明の作用】本発明に係わるアルミニウム系被溶接材
料の抵抗スポット溶接用電極は、請求項1に記載してい
るように、アルミニウム系被溶接材料の抵抗スポット溶
接に用いる電極において、電極の電気伝導度が97IA
CS%以上で、かつ、200℃以下ではビッカース硬さ
Hv80以上、400℃以上ではビッカース硬さHv3
0以下となるように、200℃から400℃の間でビッ
カース硬さがHv80以上からHv30以下に軟化する
高温硬度特性を有する材料を用いてなるものとしたか
ら、電極材料の電気伝導度と、高温での被溶接材料に対
する硬度特性がアルミニウム系被溶接材料の抵抗スポッ
ト溶接にとって最適化されたものとなり、すなわち、電
極に、被溶接材料であるアルミニウム合金の軟化特性に
あわせた高温硬度特性、つまり、特定温度域における軟
化特性をもたせることとなるので、電極先端の形状を特
定の形状とすることによりアルミニウム系被溶接材料の
抵抗スポット溶接の連続打点において電極先端の接触径
が一定に保たれることとなり、つまり、溶接時の電流密
度が一定に保たれることとなり、鋼板並みの連続打点性
と溶接部の良好なる外観品質が得られることとなって、
アルミニウム系被溶接材料の抵抗スポット溶接に際して
従来のような電極寿命が短くかつまた溶接部の外観品質
が低下するという問題点が解消されることとなる。The electrode for resistance spot welding of the aluminum-based material to be welded according to the present invention has the following features. Conductivity is 97IA
Vickers hardness Hv80 or more at CS% or more and 200 ° C. or less, Vickers hardness Hv3 at 400 ° C. or more
Since the Vickers hardness is softened from Hv80 or more to Hv30 or less between 200 ° C. and 400 ° C. so as to be 0 or less, the electrical conductivity of the electrode material, The hardness characteristics for the material to be welded at high temperature will be optimized for resistance spot welding of the aluminum-based material to be welded, that is, for the electrode, the high-temperature hardness characteristics that match the softening characteristics of the aluminum alloy that is the material to be welded, that is, , Since it has softening characteristics in a specific temperature range, by making the shape of the electrode tip a specific shape, the contact diameter of the electrode tip is kept constant at the continuous spot of resistance spot welding of the aluminum-based material to be welded. That is, the current density during welding is kept constant, and the continuous spotting property and the welded area are similar to those of steel sheets. Become that watching quality is obtained,
In the resistance spot welding of the aluminum-based material to be welded, the problem that the electrode life is short and the appearance quality of the welded portion is deteriorated is solved.
【0019】そして、本発明に係わるアルミニウム系被
溶接材料の抵抗スポット溶接用電極の実施態様において
は、請求項2に記載しているように、電極先端の形状が
電極先端にR8mm〜R40mmの曲率半径をもつR形
であって、かつ、被溶接材料の薄板側の板厚をtmmと
したときに、そのR形状の部分が少なくとも直径で6√
tmm以上確保されているものとすることによって、電
極先端に突起が容易に形成され、かつ打点数が進んでも
その突起が良好に維持されることとなって、突起消滅打
点数は大幅に増大し、連続打点性能に優れたアルミニウ
ム系被溶接材料の抵抗スポット溶接用電極となる。In the embodiment of the electrode for resistance spot welding of the aluminum-based material to be welded according to the present invention, as described in claim 2, the shape of the electrode tip has a curvature of R8 mm to R40 mm at the electrode tip. When it is R-shaped with a radius and the thickness of the thin plate side of the material to be welded is tmm, the R-shaped part is at least 6√ in diameter.
By ensuring tmm or more, the protrusions can be easily formed at the electrode tip, and the protrusions can be maintained well even if the number of dots is advanced, so that the number of dots disappeared by the protrusion is significantly increased. It becomes an electrode for resistance spot welding of aluminum-based materials to be welded, which has excellent continuous spot performance.
【0020】また、請求項3に記載しているように、電
極先端の形状が被溶接材料の薄板側の板厚をtmmとし
たときに、電極先端に直径4√tmm〜6√tmmの平
面部を有し、かつ、その外周部は曲率半径がR8mm〜
R40mmのR形であるものとすることによって、電極
先端に突起が容易に自己形成されることとなり、かつま
た打点が進行してもその突起が良好に維持されることと
なって、突起消滅打点数が大幅に増大し、連続打点性能
に優れたアルミニウム系被溶接材料の抵抗スポット溶接
用電極となる。Further, as described in claim 3, when the shape of the electrode tip is the thickness of the thin plate side of the material to be welded is tmm, the electrode tip has a flat surface with a diameter of 4√tmm to 6√tmm. And the outer periphery has a radius of curvature of R8 mm-
By adopting the R shape of R40 mm, the protrusions can be easily self-formed at the tip of the electrode, and the protrusions can be maintained well even if the spotting progresses. The number of points is greatly increased, and it becomes an electrode for resistance spot welding of aluminum-based materials to be welded, which has excellent continuous spotting performance.
【0021】あるいは、請求項4に記載しているよう
に、電極先端の形状が電極先端にR8mm〜R40mm
の曲率半径をもつR形であって、かつ、被溶接材料の薄
板側の板厚をtmmとしたときに、そのR形状の先端部
の直径が4√tmm〜6√tmmの範囲にのみ、曲率半
径がその電極の前記曲率半径よりも大きい別の曲率半径
を有した少なくとも二つ以上の複合球面ないしは複合曲
面で構成される形状を有するものとすることによって
も、突起消滅打点数は大幅に増大し、連続打点性能に優
れたアルミニウム系被溶接材料の抵抗スポット溶接用電
極となる。Alternatively, as described in claim 4, the shape of the electrode tip is R8 mm to R40 mm at the electrode tip.
R-shape having a radius of curvature of, and the thickness of the thin plate side of the material to be welded is tmm, the diameter of the tip of the R-shape is only in the range of 4√tmm to 6√tmm, The number of projection vanishing spots is also significantly increased by having a shape composed of at least two or more compound spherical surfaces or compound curved surfaces having a different radius of curvature larger than the radius of curvature of the electrode. It becomes an electrode for resistance spot welding of an aluminum-based material to be welded, which has increased in number and has excellent continuous spot performance.
【0022】あるいは、請求項5に記載しているよう
に、電極先端の形状が被溶接材料の薄板側の板厚をtm
mとしたときに、電極先端に直径4√tmm〜6√tm
mの平面部を有し、かつ、その外周部は電極の軸芯との
直交軸に対し5°〜30°の角度をもつ略テーパ形状と
した形状を有するものとすることによっても、突起消滅
打点数は大幅に増大し、連続打点性能に優れたアルミニ
ウム系被溶接材料の抵抗スポット溶接用電極となる。Alternatively, as described in claim 5, the shape of the electrode tip is the thickness tm of the material to be welded on the thin plate side.
When m, the diameter of the electrode tip is 4√tmm to 6√tm
The protrusion disappears also by having a flat portion of m and an outer peripheral portion having a substantially tapered shape with an angle of 5 ° to 30 ° with respect to an axis orthogonal to the axis of the electrode. The number of spots is greatly increased, and it becomes an electrode for resistance spot welding of aluminum-based materials to be welded, which has excellent continuous spot performance.
【0023】あるいは、請求項6に記載しているよう
に、電極先端の形状が被溶接材料の薄板側の板厚をtm
mとしたときに、電極先端に直径4√tmm〜6√tm
mの範囲にのみ、適宜な曲率半径をもつ球面部を有し、
かつ、その外周部は電極の軸芯との直交軸に対し5°〜
30°の角度をもつ略テーパ形状とした形状を有するも
のとすることによっても、突起消滅打点数は大幅に増大
し、連続打点性能に優れたアルミニウム系被溶接材料の
抵抗スポット溶接用電極となる。Alternatively, as described in claim 6, the shape of the electrode tip is the thickness tm of the thin plate side of the material to be welded.
When m, the diameter of the electrode tip is 4√tmm to 6√tm
Only in the range of m, there is a spherical portion having an appropriate radius of curvature,
And, the outer peripheral portion is 5 ° to the axis orthogonal to the axis of the electrode.
By forming a substantially tapered shape having an angle of 30 °, the number of spots at which protrusions disappear is greatly increased, and the electrode becomes a resistance spot welding electrode of an aluminum-based material to be welded having excellent continuous spot performance. .
【0024】あるいは、請求項7に記載しているよう
に、電極先端の形状が被溶接材料の薄板側の板厚をtm
mとしたときに、電極先端に直径4√tmm〜6√tm
mで、高さ0.1tmm〜0.3tmmとなる突起を設
け、かつ、前記突起の外周部には前記突起の外壁から全
周にわたって少なくとも1mm以上の平坦部を形成した
形状とすることによっても、突起消滅打点数は大幅に増
大し、連続打点性能に優れたアルミニウム系被溶接材料
の抵抗スポット溶接用電極となる。Alternatively, as described in claim 7, the shape of the electrode tip is the thickness tm of the thin plate side of the material to be welded.
When m, the diameter of the electrode tip is 4√tmm to 6√tm
Also, by providing a protrusion having a height of 0.1 tmm to 0.3 tmm in m, and forming a flat portion of at least 1 mm or more over the entire circumference from the outer wall of the protrusion on the outer peripheral portion of the protrusion. The number of spots for vanishing projections is greatly increased, and the electrode becomes a resistance spot welding electrode of an aluminum-based material to be welded having excellent continuous spot performance.
【0025】そして、請求項8に記載しているように、
前記突起の角部または外壁部と、平坦部とを適宜な曲率
半径をもつ曲面でつないだ形状とすることによって、ま
た、請求項9に記載しているように、前記突起の先端形
状が平面であるものとすることによって、あるいは、請
求項10に記載しているように、前記突起の先端形状が
適宜な曲率半径を有した球面であるものとすることによ
って、3000打点を超える以上に電極先端の突起が維
持され、連続打点性能が著しく向上したものとなる。Then, as described in claim 8,
By forming a shape in which a corner portion or an outer wall portion of the projection and a flat portion are connected by a curved surface having an appropriate curvature radius, and as described in claim 9, the tip shape of the projection is a flat surface. Or by setting the tip shape of the projection to be a spherical surface having an appropriate radius of curvature as described in claim 10, The protrusion at the tip is maintained and the continuous dot performance is significantly improved.
【0026】さらに、本発明に係わるアルミニウム系被
溶接材料の抵抗スポット溶接方法は、請求項11に記載
しているように、アルミニウム系被溶接材料を抵抗スポ
ット溶接するに際し、電極の電気伝導度が97IACS
%以上で、かつ、電極と被溶接材料との硬度差がビッカ
ース硬さにおいて、200℃以下ではHv20以上であ
り、250℃〜400℃の温度範囲の間ではHv15以
下となるような電極と被溶接材料とを用いて溶接を行う
ようにしたから、電極材料の電気伝導度と、高温での被
溶接材料に対する硬度特性がアルミニウム系被溶接材料
に対する抵抗スポット溶接にとって最適化されたものと
なり、鋼板並みの連続打点性と溶接部の良好なる外観品
質が得られることとなる。Further, in the resistance spot welding method for an aluminum-based material to be welded according to the present invention, as described in claim 11, when the resistance spot welding is performed on the aluminum-based material to be welded, the electrical conductivity of the electrode is reduced. 97IACS
% And the Vickers hardness difference between the electrode and the material to be welded is Hv20 or more at 200 ° C. or less and Hv15 or less at a temperature range of 250 ° C. to 400 ° C. Since the welding is performed using the welding material, the electrical conductivity of the electrode material and the hardness characteristics of the welding material at high temperature are optimized for resistance spot welding of the aluminum welding material. It is possible to obtain an average continuous spotting property and a good appearance quality of the welded portion.
【0027】そして、本発明に係わるアルミニウム系被
溶接材料の抵抗スポット溶接用電極および抵抗スポット
溶接方法の実施態様においては、請求項12に記載して
いるように、電極の材質がタフピッチ銅であるものとす
ることによって、また、請求項13に記載しているよう
に、電極の材質が無酸素銅であるものとすることによっ
て、入手の容易な電極材料を用いて連続打点性能に優れ
たアルミニウム系被溶接材料の抵抗スポット溶接用電極
になると共に、溶接部の良好なる外観が得られることと
なる。In an embodiment of the resistance spot welding electrode and the resistance spot welding method for an aluminum-based material to be welded according to the present invention, as described in claim 12, the material of the electrode is tough pitch copper. In addition, as described in claim 13, the material of the electrode is oxygen-free copper, so that aluminum having excellent continuous dot performance using an easily available electrode material can be used. In addition to being an electrode for resistance spot welding of the material to be welded, a good appearance of the welded portion can be obtained.
【0028】[0028]
【実施例】以下、本発明の実施例を図面に基づいて説明
する。Embodiments of the present invention will be described below with reference to the drawings.
【0029】表1は本発明の一実施例および二つの従来
例を示す。Table 1 shows one embodiment of the present invention and two conventional examples.
【0030】表1に示すように、本発明の一実施例の抵
抗スポット溶接用電極は、タフピッチ銅(C1100−
F)を素材とし、電気伝導度が100IACS%超過、
常温でのビッカース硬さがHv104,200℃でのビ
ッカース硬さがHv82,400℃でのビッカース硬さ
がHv21の特性を有するものである。As shown in Table 1, the resistance spot welding electrode of one embodiment of the present invention was manufactured by using tough pitch copper (C1100-
F) as a material, and the electrical conductivity exceeds 100 IACS%,
The Vickers hardness at room temperature is Hv104, the Vickers hardness at 200 ° C is Hv82, and the Vickers hardness at 400 ° C is Hv21.
【0031】一方、従来例1のスポット溶接用電極は、
クロム銅(Cu−Cr)を素材とし、電気伝導度が75
〜85IACS%、常温でのビッカース硬さがHv15
9,200℃でのビッカース硬さがHv138,400
℃でのビッカース硬さがHv96の特性を有するもので
ある。On the other hand, the spot welding electrode of Conventional Example 1 is
Made of chrome copper (Cu-Cr) and has an electric conductivity of 75
~ 85IACS%, Vickers hardness at room temperature is Hv15
Vickers hardness at 9,200 ℃ is Hv138,400
The Vickers hardness at ° C has a characteristic of Hv96.
【0032】他方、従来例3の抵抗スポット溶接用電極
は、含Ag導電用銅合金(Cu−Ag)を素材とし、電
気伝導度が95〜97IACS%、常温でのビッカース
硬さが117の特性を有するものである。On the other hand, the resistance spot welding electrode of Conventional Example 3 is made of Ag-containing copper alloy for conduction (Cu-Ag) as a raw material, has an electric conductivity of 95 to 97 IACS% and a Vickers hardness of 117 at room temperature. Is to have.
【0033】また、被溶接材料は、Al−4.5重量%
MgよりなるJIS 5000系のアルミニウム系被溶
接材料であり、常温でのビッカース硬さがHv65,2
00℃でのビッカース硬さがHv58,400℃でのビ
ッカース硬さがHv8の特性を有するものである。The material to be welded is Al-4.5% by weight.
It is a JIS 5000 series aluminum-based material to be welded made of Mg and has a Vickers hardness of Hv65,2 at room temperature.
The Vickers hardness at 00 ° C. is Hv58, and the Vickers hardness at 400 ° C. is Hv8.
【0034】[0034]
【表1】 [Table 1]
【0035】図1には、本発明の一実施例による抵抗ス
ポット溶接用電極と、従来例1の抵抗スポット溶接用電
極および被溶接材料であるアルミニウム合金圧延材(J
IS5000系)のそれぞれの温度−硬さ特性を示して
いる。図1より明らかなように、従来例1の電極(クロ
ム銅)では、主に鋼板の溶接に対応するため、高温でも
硬さを維持するような高温硬度特性を示している。FIG. 1 shows a resistance spot welding electrode according to an embodiment of the present invention, a resistance spot welding electrode of Conventional Example 1 and a rolled aluminum alloy material (J) to be welded.
The respective temperature-hardness characteristics of (IS5000 series) are shown. As is clear from FIG. 1, the electrode (Chromium copper) of Conventional Example 1 mainly corresponds to welding of steel plates, and therefore exhibits high-temperature hardness characteristics that maintain hardness even at high temperatures.
【0036】一方、本発明による電極は、ここでは一例
として電気伝導度が100IACS%超過のタフピッチ
銅を用いるとともに、被溶接材料として用いた5000
系アルミニウム合金圧延材で、板厚1.0mmのものに
ついてそれぞれの高温硬度特性を示している。On the other hand, in the electrode according to the present invention, as an example, tough pitch copper having an electric conductivity of more than 100 IACS% is used here, and 5000 is used as a material to be welded.
The high-temperature hardness characteristics of rolled aluminum alloys with a plate thickness of 1.0 mm are shown.
【0037】図1より明らかなように、本発明の電極
は、200℃から400℃の間で大きく硬さが軟化する
特性を有しており、特に250℃から350℃の間では
被溶接材料の硬さと本発明による電極の硬さが極めて近
接している。As is clear from FIG. 1, the electrode of the present invention has the characteristic that the hardness is greatly softened between 200 ° C. and 400 ° C., and particularly, the material to be welded is heated between 250 ° C. and 350 ° C. And the hardness of the electrode according to the invention are very close.
【0038】このように、溶接通電中の電極先端部近傍
の温度範囲において、電極に、被溶接材料であるアルミ
ニウム合金の軟化特性にあわせた高温硬度特性、つまり
特定温度域における軟化特性をもたせることにより、こ
のような電極と被溶接材料とを組み合わせて連続的なス
ポット溶接を繰り返していくと、図2(A)に示した初
期の電極1の形状が、溶接打点の増加とともに、被溶接
材料の溶接部表面に生じたくぼみに対応して、電極1の
先端部に図2(B)に示したような突起1aが形成され
てくる。Thus, in the temperature range near the tip of the electrode during welding current application, the electrode should have high-temperature hardness characteristics that match the softening characteristics of the aluminum alloy that is the material to be welded, that is, the softening characteristics in a specific temperature range. Thus, when such an electrode and the material to be welded are combined and continuous spot welding is repeated, the initial shape of the electrode 1 shown in FIG. A protrusion 1a as shown in FIG. 2 (B) is formed at the tip of the electrode 1 corresponding to the depression formed on the surface of the welded portion.
【0039】また同時に、突起1aの外周部には連続打
点とともに平坦部1bが同様に形成されてくる。そし
て、後述するように、本発明の電極ではこれらによって
電極の接触径の拡大が抑制され、アルミニウム合金のス
ポット溶接における連続打点性を鋼板並みにまで飛躍的
に向上させることができることとなる。At the same time, a flat portion 1b is similarly formed on the outer peripheral portion of the protrusion 1a together with continuous hit points. Then, as will be described later, in the electrode of the present invention, the expansion of the contact diameter of the electrode is suppressed by these, and it is possible to dramatically improve the continuous spotting property in spot welding of an aluminum alloy to the level of a steel plate.
【0040】次に作用を説明する。Next, the operation will be described.
【0041】本発明による電極と従来例1および従来例
3に示す電極として、それぞれ図2(A)に示すよう
に、電極先端の曲率半径RDが、ここでは一例としてR
20の球面とした電極1を用い、5000系アルミニウ
ム合金を被溶接材料として用いて、連続打点試験を実施
した。As shown in FIG. 2 (A), the radius of curvature RD of the electrode tip of the electrode according to the present invention and the electrodes shown in Conventional Example 1 and Conventional Example 3 is R as an example here.
A continuous welding point test was performed using the electrode 1 having 20 spherical surfaces and using a 5000 series aluminum alloy as the material to be welded.
【0042】この連続打点試験に用いた被溶接材料およ
び電極の材質、特性は表1に示したとおりであり、この
試験の溶接条件は表2に示す如くである。The materials and properties of the materials to be welded and the electrodes used in this continuous spot test are as shown in Table 1, and the welding conditions of this test are as shown in Table 2.
【0043】[0043]
【表2】 [Table 2]
【0044】また、連続打点性の評価方法は、強度また
はナゲット径が、JIS Z3140−1989に制定
されるA級最小値、つまり、引張剪断強度が172kg
f、ナゲット径が4mmのいずれかを早く割った方の打
点数を連続打点数とした。ただし、最大9000点まで
でその後の試験は中断した。Further, the evaluation method of the continuous hitting property is that the strength or the nugget diameter is the Class A minimum value established in JIS Z3140-1989, that is, the tensile shear strength is 172 kg.
f or the nugget diameter of 4 mm, whichever was earlier divided, was defined as the number of consecutive dots. However, the subsequent test was interrupted at a maximum of 9,000 points.
【0045】本発明による電極は、前述したように、所
定の高温硬度特性、つまり高温での軟化特性を備えてい
るため、溶接打点初期にスポット溶接により生じた被溶
接材料表面のくぼみに対応して、溶接熱により軟化した
電極1の先端部が比較的容易に変形し、図2(B)に示
すように、突起1aを自己形成する。また、溶接時の加
圧力は主に突起1aの外周部で受圧するため、その外周
部には平坦部1bが自己形成される。そして、打点初期
に溶接部表面のくぼみに対応して自己形成された突起1
aは、打点が進んでも被溶接材料のくぼみによって突起
1aの外径部1cが外側へ拡大する方向に対して拘束さ
れるため、突起1aの外径部1cの拡大が阻止される。As described above, the electrode according to the present invention has a predetermined high temperature hardness characteristic, that is, a softening characteristic at a high temperature, and therefore corresponds to the depression of the surface of the material to be welded which is caused by spot welding at the initial stage of the welding point. Then, the tip portion of the electrode 1 softened by the welding heat is relatively easily deformed to self-form the protrusion 1a as shown in FIG. 2 (B). Further, since the pressure applied during welding is mainly received by the outer peripheral portion of the protrusion 1a, the flat portion 1b is self-formed on the outer peripheral portion. Then, the protrusion 1 self-formed corresponding to the depression on the surface of the welded portion at the initial stage of hitting
Since a is restrained in the direction in which the outer diameter portion 1c of the projection 1a expands outward due to the depression of the material to be welded even if the hit point advances, the expansion of the outer diameter portion 1c of the projection 1a is prevented.
【0046】したがって、接触径は突起1aの外径d1
で一定に維持されるため、溶接時の電流密度も低下しな
い。したがって、これによって、鋼板並みの連続打点性
が可能となる。Therefore, the contact diameter is the outer diameter d 1 of the protrusion 1a.
The current density during welding does not decrease because it is maintained at a constant value. Therefore, this makes it possible to achieve continuous hitting properties comparable to those of steel plates.
【0047】なお、ここで、接触径とは、感圧紙を電極
と被溶接材料との間にはさんで、電極の被溶接材料表面
に接触する部分の直径(図2(B)ではd1、図2
(C)ではd2)を測定した値である。Here, the contact diameter means the diameter of the portion of the electrode that contacts the surface of the material to be welded, sandwiching the pressure sensitive paper between the electrode and the material to be welded (d 1 in FIG. 2B). , Fig. 2
In (C), it is a value obtained by measuring d 2 ).
【0048】連続打点試験中の本発明による電極ならび
に従来例1および従来例3の電極における接触径の連続
打点数による変化を図3に示す。FIG. 3 shows changes in the contact diameter of the electrode according to the present invention and the electrodes of Conventional Example 1 and Conventional Example 3 during the continuous spot test with the number of continuous spots.
【0049】図3より明らかなように、本発明の電極で
は、前述したように、電極先端に突起1aが自己形成さ
れ、かつそれが維持されるため、打点数が進んでも接触
径はほぼ一定に保たれるのに対し、従来例1の電極では
打点初期から急速に接触径が拡大し、約1000打点で
電極寿命となった。As is apparent from FIG. 3, in the electrode of the present invention, the protrusion 1a is self-formed at the tip of the electrode and is maintained as described above, so that the contact diameter is substantially constant even if the number of dots is increased. On the other hand, in the electrode of Conventional Example 1, the contact diameter rapidly expanded from the initial point of the hitting point, and the electrode life reached about 1000 hitting points.
【0050】また、従来例3の電極では、ピックアップ
劣化が起こりにくいが、軟化温度を400℃と高くし
て、高温での電極の軟化をむしろ抑制するような材料と
しているため、本発明のような突起1aの形成現象はみ
られず、このため、従来例1の電極よりは接触径の拡大
は緩やかではあるものの、打点数が増すと接触径の拡大
は避けられず、約3000打点で電極寿命に至った。Further, in the electrode of Conventional Example 3, the deterioration of the pickup is unlikely to occur, but the softening temperature is set to 400 ° C. to make the material rather suppress the softening of the electrode at a high temperature. The formation of the protrusions 1a was not observed. Therefore, although the contact diameter expanded more slowly than the electrode of Conventional Example 1, the contact diameter did not increase as the number of dots increased, and the electrode diameter reached about 3000 dots. It has reached the end of its life.
【0051】これに対し、本発明による電極はピックア
ップ劣化がなく、溶接部の外観品質は良好であることは
もちろん、8000打点を超えてもまだ寿命には至らな
かった。On the other hand, the electrode according to the present invention had no pickup deterioration and the appearance quality of the welded portion was good, and the life was still not reached even after 8,000 hit points.
【0052】なお、連続打点性は、図3のような電極先
端の接触径の推移からほぼ推定することが可能であり、
図3より従来例に対する本発明の効果は明らかである。The continuous hitting property can be almost estimated from the transition of the contact diameter of the electrode tip as shown in FIG.
The effect of the present invention on the conventional example is clear from FIG.
【0053】図4には本発明による電極および溶接方法
による連続打点試験の結果を示しており、8000打点
を超えてもまだほぼ一定したナゲット径を有していて十
分な強度を満足しており、鋼板並みの連続打点性を確保
することができた。FIG. 4 shows the results of a continuous spot test by the electrode and the welding method according to the present invention. Even after 8000 spots, the nugget diameter was still almost constant and sufficient strength was satisfied. It was possible to secure continuous hitting properties similar to steel plates.
【0054】なお、図2(C)は従来例1に示す電極1
1を用いた場合における連続打点試験後の電極の劣化形
態を示したものであり、電極先端にはへこみ11aが生
じるとともに、接触径d2は拡大している。Incidentally, FIG. 2C shows the electrode 1 shown in Conventional Example 1.
1 shows a deterioration form of the electrode after the continuous dot test in the case of using No. 1, indentation 11a is generated at the electrode tip and the contact diameter d 2 is enlarged.
【0055】図5には他の実施例を示す。FIG. 5 shows another embodiment.
【0056】図5はR形電極の曲率半径の最適範囲を調
査した実験結果を示す。ここで、R形電極とは、前述し
た図2(A)に示すように電極1の先端に一定の曲率半
径RDの球面を設けている形状であり、本実験ではR8
mm,R20mm,R40mm,R75mm,R150
mmとした電極と、Rを無限大として電極先端を平面と
したフラット電極を用いて実験した。なお、被溶接材料
は5000系アルミニウム合金で板厚1.0mmのもの
を使用した。また、溶接条件は前記実施例の表2におい
て示したものと同じである。FIG. 5 shows the experimental results of investigating the optimum range of the radius of curvature of the R-shaped electrode. Here, the R-shaped electrode is a shape in which a spherical surface having a constant radius of curvature RD is provided at the tip of the electrode 1 as shown in FIG.
mm, R20mm, R40mm, R75mm, R150
An experiment was conducted using an electrode having a thickness of mm and a flat electrode having a flat electrode tip with R being infinite. The material to be welded was a 5000 series aluminum alloy with a plate thickness of 1.0 mm. The welding conditions are the same as those shown in Table 2 of the above embodiment.
【0057】図5の縦軸は突起消滅打点数を示してお
り、突起1aの高さ(図2(B)のh)が所要寸法を維
持できなくなった打点数を表わしており、この突起消滅
打点数によって電極寿命を評価することができる。本実
験では、前述したとおり、感圧紙による接触径の測定時
に、通常は図6(A)に示すような円形打痕2が感圧紙
に残され、この円形打痕2の直径を測定して接触径とし
ているが、前述したように、突起1aの高さが所定高さ
以下になると、図6(B)に示すように円形打痕2のほ
かに三日月形打痕3が生じてくる。そこで、この三日月
形打痕3が初めて生じた打点数を、本実験での突起消滅
打点数としている。The vertical axis of FIG. 5 represents the number of points where the protrusion disappears, and the height of the protrusion 1a (h in FIG. 2B) represents the number of points where the required dimension cannot be maintained. The electrode life can be evaluated by the number of dots. In the present experiment, as described above, when measuring the contact diameter with the pressure-sensitive paper, the circular dent 2 as shown in FIG. 6 (A) is usually left on the pressure-sensitive paper, and the diameter of the circular dent 2 is measured. Although the contact diameter is used, as described above, when the height of the protrusion 1a becomes equal to or lower than the predetermined height, a crescent-shaped dent 3 is formed in addition to the circular dent 2 as shown in FIG. 6B. Therefore, the number of dots at which the crescent-shaped dent 3 is firstly generated is set as the number of dots at which the protrusion disappears in this experiment.
【0058】図5に示す本実験の結果、本発明による電
極は、電極先端形状がR形の場合、その曲率半径RDが
R8mm〜R40mmの範囲では打点数が3000打点
を超えても電極先端の突起は消滅しなかったが、R75
mmおよびR150mmでは500打点以下で消滅し
た。また、フラット電極では突起が形成されなかった。As a result of the experiment shown in FIG. 5, in the electrode according to the present invention, when the shape of the electrode tip is R, the radius of curvature RD is in the range of R8 mm to R40 mm, and the electrode tip of the electrode tip exceeds 3000 even if the number of points exceeds 3000. The protrusion did not disappear, but R75
mm and R150 mm, it disappeared at 500 points or less. No protrusion was formed on the flat electrode.
【0059】以上のことから、電極先端に突起が容易に
形成され、かつ打点数が進んでもその突起が維持される
R形電極の形状は、曲率半径RDがR8mm〜R40m
mの範囲が望ましいことが分かる。From the above, the shape of the R-shaped electrode in which the projection is easily formed at the tip of the electrode and the projection is maintained even when the number of hit points is advanced is such that the radius of curvature RD is R8 mm to R40 m.
It can be seen that the range of m is desirable.
【0060】電極先端への突起の形成は、前述したよう
に、被溶接材料に生じるくぼみの転写によるものである
ため、打点初期に被溶接材料の溶接部表面にある程度の
深さのくぼみを形成するような電極先端形状が必要とな
るため、電極先端の曲率半径RDは大きすぎると所要の
高さをもった突起が形成されない。また形成した突起の
直径と高さの維持には、主に、加圧力を分担して突起の
潰れや食い込みを抑制するための突起外周平坦部(図2
(B)における平坦部1b)が必要となる。このため、
曲率半径RDが小さすぎると、突起は比較的容易に形成
されるが、突起外周平坦部1bの面積が狭いので突起は
すぐに消滅してしまい、突起高さが維持できない。As described above, the formation of the projection on the tip of the electrode is due to the transfer of the depression formed in the material to be welded. Therefore, the depression having a certain depth is formed on the surface of the welded portion of the material to be welded at the initial stage of the welding point. Therefore, if the radius of curvature RD of the electrode tip is too large, a protrusion having a required height cannot be formed. In addition, in order to maintain the diameter and height of the formed protrusion, the protrusion outer peripheral flat portion (Fig. 2) is mainly used to share the pressure force and suppress the protrusion's crushing and biting.
The flat portion 1b) in (B) is required. For this reason,
If the radius of curvature RD is too small, the protrusions are relatively easily formed, but since the area of the outer peripheral flat portion 1b of the protrusion is small, the protrusion disappears immediately and the height of the protrusion cannot be maintained.
【0061】より具体的には、被溶接材料の板厚をtm
mとしたとき、理想的な突起径は4√tmm〜6√tm
m、突起高さは0.1tmm〜0.3tmm、そしてこ
のとき、突起外周平坦部1bは、電極形状がR8mmの
ときに幾何学的に決定されるように少なくともその直径
が「突起外径+2mm」以上の平坦部1bを必要とす
る。More specifically, the plate thickness of the material to be welded is tm
When m, the ideal projection diameter is 4√tmm to 6√tm
m, the projection height is 0.1 tmm to 0.3 tmm, and at this time, the projection outer peripheral flat portion 1b has at least the diameter "projection outer diameter + 2 mm" as geometrically determined when the electrode shape is R8 mm. The above flat part 1b is required.
【0062】したがって、電極先端の曲率半径RDの範
囲はR8mm〜R40mmが連続打点性向上に最も効果
的な突起が自己形成されそして打点数が進んでも突起の
径と高さが維持され易い形状であり、連続打点性能に優
れた電極形状であると言える。また、この曲率半径RD
部分は、突起1aおよびその外周部に平坦部1bを形成
するため、少なくとも直径で6√tmm以上の広さを確
保することが必要である。Therefore, the radius of curvature RD of the tip of the electrode is in the range of R8 mm to R40 mm, in which the most effective protrusions for improving the continuous spotting property are self-formed, and the diameter and height of the protrusions are easily maintained even if the number of spots increases. Therefore, it can be said that the electrode shape is excellent in continuous dot performance. Also, this radius of curvature RD
Since the portion forms the protrusion 1a and the flat portion 1b on the outer peripheral portion thereof, it is necessary to secure at least a width of 6√tmm or more in diameter.
【0063】図7にはさらに他の実施例を示す。FIG. 7 shows still another embodiment.
【0064】図7は種々の電極形状における突起消滅打
点数を比較した実験結果を示す。また、図8(A)
(B)(C)および図9(A)(B)にはこの実験に使
用した電極形状を示す。FIG. 7 shows the result of an experiment comparing the number of points of vanishing protrusions in various electrode shapes. In addition, FIG. 8 (A)
9B and 9C and FIGS. 9A and 9B show the electrode shapes used in this experiment.
【0065】このうち、図8(A)はR形の先端部に、
被溶接材料の板厚をtmmとしたとき、直径4√tmm
〜6√tmmの平面部1dを設けたRF形電極1(R
F)を示しており、図8(B)はR形電極の先端部の直
径4√tmm〜6√tmmの範囲のみ曲率半径を大きく
した別のR部分(r1)を設けたRR形電極1(RR)
を示しており、図8(C)は電極の半径と等しい曲率半
径R(R2)を持った電極において先端部の直径4√t
mm〜6√tmmの範囲のみ曲率半径を大きくした別の
R部分(r2)を設けたDR形電極1(DR)を示して
いる。Of these, FIG. 8A shows that the R-shaped tip is
When the plate thickness of the material to be welded is tmm, the diameter is 4√tmm
RF type electrode 1 (R
FIG. 8 (B) is an RR-shaped electrode in which another R portion (r 1 ) having a larger radius of curvature is provided only in the range of diameters 4√tmm to 6√tmm of the tip of the R-shaped electrode. 1 (RR)
FIG. 8C shows an electrode having a radius of curvature R (R 2 ) equal to the radius of the electrode, and the diameter of the tip portion is 4√t.
The DR type electrode 1 (DR) is shown in which another R portion (r 2 ) having a large radius of curvature is provided only in the range of mm to 6√tmm.
【0066】また、図9(A)は電極先端に直径5.5
mmの平坦部1eを有した高さ0.2mmの突起1a
と、その外周部に直径12mmの突起外周平坦部1bを
有した突起F形電極1(突起F)を示しており、図9
(B)は突起1aの先端部を曲率半径をもった球面(r
3)とした以外は図9(A)と同様とした突起R形電極
1(突起R)を示している。Further, in FIG. 9A, the electrode tip has a diameter of 5.5.
0.2 mm high protrusion 1a having a flat portion 1e of mm
9 shows a protrusion F-shaped electrode 1 (protrusion F) having a protrusion outer peripheral flat portion 1b having a diameter of 12 mm on the outer periphery thereof.
In (B), the tip of the protrusion 1a is a spherical surface (r
3) and other than the shows the projection R-shaped electrodes 1 (projections R) which was the same as FIG. 9 (A).
【0067】本発明に示す高温硬度特性を有した電極材
料を用いてこれらの電極形状に加工し、前記実施例と同
様にして突起消滅打点数によってこれら種々の電極形状
の連続打点性を前記実施例のR20形電極と比較評価し
た結果を図7に示す。なお、溶接条件および評価方法等
は前記実施例と同じである。The electrode materials having the high temperature hardness characteristics shown in the present invention were used to form these electrode shapes, and the continuous dotability of these various electrode shapes was determined by the number of the points where the projections disappeared in the same manner as in the above embodiment. The results of comparative evaluation with the R20 type electrode of the example are shown in FIG. The welding conditions, the evaluation method and the like are the same as those in the above-mentioned embodiment.
【0068】図7より明らかなように、RF形電極1
(RF)、RR形電極1(RR)、DR形電極1(D
R)、突起F形電極1(突起F)、突起R形電極1(突
起R)のいずれの電極とも、R20形電極と同様に、3
000打点を超えるまで電極先端の突起が維持され、そ
の連続打点性の向上効果が認められた。As is apparent from FIG. 7, the RF type electrode 1
(RF), RR type electrode 1 (RR), DR type electrode 1 (D
R), projection F-shaped electrode 1 (projection F), and projection R-shaped electrode 1 (projection R) are the same as the R20-shaped electrode.
The protrusions at the electrode tip were maintained until the number of hit points exceeded 000, and the effect of improving the continuous hit property was recognized.
【0069】図8(A)(B)(C)に示す電極形状
は、いずれも、電極先端に突起を形成する部分は平面で
あれ、曲率半径を有した球面であれ、その直径を被溶接
材料の板厚をtmmとしたときに4√tmm〜6√tm
mとしており、かつ、その外周部の突起外周平坦部を形
成する部分を曲率半径がR8mm〜R40mmとなるよ
うにしているため、前記実施例と同様に、理想的な突起
を形成し、また、打点数が進んでもその突起高さと径を
維持することができる形状となっているので、電極とし
ての連続打点性能が高い。したがって、図8(C)に示
す電極の先端R(r2)部分を4√tmm〜6√tmm
の範囲のみ平面としたDF形電極でも同様の効果が得ら
れる。In any of the electrode shapes shown in FIGS. 8A, 8B, and 8C, the diameter of the electrode to be welded, whether it is a flat portion or a spherical surface having a radius of curvature, forms a protrusion at the electrode tip. 4√tmm to 6√tm when the plate thickness of the material is tmm
Since the radius of curvature is R8 mm to R40 mm for the portion of the outer peripheral portion that forms the protrusion outer peripheral flat portion, an ideal protrusion is formed, as in the above-described embodiment, and Since the height and diameter of the protrusions can be maintained even if the number of dots is increased, the continuous dot performance as an electrode is high. Therefore, the tip R (r 2 ) portion of the electrode shown in FIG.
Similar effects can be obtained even with a DF-shaped electrode having a flat surface only in the range.
【0070】また、図9(A)(B)に示す電極形状
は、R形電極の場合に自己形成される電極形状を電極の
初期形状としたものであり、突起直径を4√tmm〜6
√tmm,突起高さを0.1tmm〜0.3tmm,突
起外周平坦部をすくなくとも突起径+2mm以上として
いるため、打点数が進んでも理想的な突起の高さと径が
維持される形状となっており、連続打点性能の高い電極
形状となる。なお、突起1aの外壁部と突起外周平坦部
1bの角部には適宜な曲率半径(r4)を有した曲面に
より先端形状を構成してもよい。The electrode shape shown in FIGS. 9 (A) and 9 (B) is an electrode shape that is self-formed in the case of an R-shaped electrode and has a projection diameter of 4√tmm-6.
√tmm, protrusion height is 0.1tmm to 0.3tmm, and the protrusion outer diameter flatness is at least 2mm or more so that the ideal height and diameter of the protrusion can be maintained even if the number of points increases. The electrode shape has a high continuous dot performance. Note that the outer wall portion of the protrusion 1a and the corner portion of the protrusion outer peripheral flat portion 1b may have a tip shape formed by a curved surface having an appropriate radius of curvature (r 4 ).
【0071】図10および図11にはさらに他の実施例
を示す。10 and 11 show still another embodiment.
【0072】図11は、図10に示すようなコーン形電
極1のコーン部1fのテーパ部角度(θ)を種々変化さ
せて、前記実施例と同様の連続打点試験を3000打点
まで行い、その電極の連続打点性能を評価した結果を示
す。In FIG. 11, the taper angle (θ) of the cone portion 1f of the cone-shaped electrode 1 as shown in FIG. 10 is variously changed, and the same continuous dot test as in the above embodiment is conducted up to 3000 dots. The result of having evaluated the continuous spotting performance of the electrode is shown.
【0073】ここで用いた電極は本発明による高温硬度
特性を有した電極材料を用い、図10において電極先端
部に、被溶接材料の板厚をtmmとしたとき、直径が4
√tmm〜6√tmmの平坦部(d3)を設けるととも
に、その囲りに、電極の軸芯との直交に対し所定の角度
(θ)をもったテーパ形状としたコーン形電極1を用い
た。The electrode used here is an electrode material having high temperature hardness characteristics according to the present invention, and the diameter of the electrode tip is 4 mm when the plate thickness of the material to be welded is tmm in FIG.
Provide a flat portion (d 3 ) of √tmm to 6√tmm, and use a cone-shaped cone-shaped electrode 1 having a tapered shape with a predetermined angle (θ) with respect to the orthogonal to the axis of the electrode in the surrounding area. I was there.
【0074】本実施例では、一例として、平坦部
(d3)の直径をφ5.5mm、テーパ角度(θ)を5
°、15°、30°、45°、60°の5種類とした電
極1(CF)を用い、被溶接材料として5000系アル
ミニウム合金圧延材で板厚1.0mmのものを用いた。
なお、溶接条件および評価方法等は前記実施例と同様で
ある。In the present embodiment, as an example, the diameter of the flat portion (d 3 ) is φ5.5 mm and the taper angle (θ) is 5.
Five kinds of electrodes 1 (CF) of °, 15 °, 30 °, 45 ° and 60 ° were used, and a 5000 series aluminum alloy rolled material having a plate thickness of 1.0 mm was used as a material to be welded.
The welding conditions, the evaluation method and the like are the same as those in the above-mentioned embodiment.
【0075】この結果、図11に示すように、テーパ角
度(θ)が5°、15°、30°の3種の電極では、前
記実施例と同様に、電極先端に所要形状の突起が形成さ
れ、また、3000打点までこれが維持されたが、テー
パ角度(θ)の大きい45°、60°の両電極は、その
先端に突起は形成されるものの、打点数の増加とともに
比較的早期(実験では約500打点)に所要の突起高さ
が維持できず、突起は消滅した。As a result, as shown in FIG. 11, in the three kinds of electrodes having the taper angles (θ) of 5 °, 15 °, and 30 °, the projections of the required shape are formed at the electrode tips, as in the above-mentioned embodiment. This was maintained up to 3000 hit points, but both electrodes with a large taper angle (θ) of 45 ° and 60 ° had protrusions formed at their tips, but as the number of hit points increased, it was relatively early (experimental). However, the required protrusion height could not be maintained at about 500 points, and the protrusion disappeared.
【0076】従って、図10に示すようなコーン形電極
1の場合は、コーン部1fのテーパ角度(θ)が5°〜
30°においては、前記実施例と同様に高い連続打点性
能が得られる電極形状であるといえる。このようなコー
ン形電極形状の場合、電極先端部の直径を、被溶接材料
の板厚をtmmとしたとき、4√tmm〜6√tmmと
しているため、溶接時に被溶接材料表面に生じたくぼみ
に対応して比較的容易に電極先端に突起は形成された
が、コーン部1fのテーパ角度(θ)が30°よりも大
きいと、突起の外周部に形成され、溶接時に電極加圧力
を受圧する平坦部の面積が狭くなる。このため、加圧力
による面圧が高くなり、形成された突起も含めて、電極
先端部付近がつぶされていくことにより、打点数の増加
とともに電極先端の突起の高さが減少していき、比較的
早期に電極寿命に至るので、テーパ角度(θ)は30°
以下とするのがよい。Therefore, in the case of the cone-shaped electrode 1 as shown in FIG. 10, the taper angle (θ) of the cone portion 1f is 5 ° to.
At 30 °, it can be said that the electrode has a shape capable of obtaining high continuous dot performance as in the case of the above embodiment. In the case of such a cone-shaped electrode shape, the diameter of the electrode tip is 4√tmm to 6√tmm when the plate thickness of the material to be welded is tmm. Correspondingly, a protrusion was formed on the tip of the electrode relatively easily. However, if the taper angle (θ) of the cone portion 1f is larger than 30 °, it is formed on the outer periphery of the protrusion and receives the electrode pressure force during welding. The area of the flat portion is reduced. Therefore, the surface pressure due to the applied pressure becomes high, and the vicinity of the electrode tip including the formed protrusion is crushed, and the height of the protrusion at the electrode tip decreases as the number of dots increases. Since the electrode life is reached relatively early, the taper angle (θ) is 30 °.
The following is recommended.
【0077】そして、このテーパ角度(θ)が30°以
下の電極の場合は、突起外周部に所要の面積をもつ平坦
部が形成されるため、前記実施例と同様の突起が形成さ
れるとともに、打点数が進んでも突起の高さと径が一定
に保たれることから連続打点性能が高い。In the case of an electrode having a taper angle (θ) of 30 ° or less, a flat portion having a required area is formed on the outer peripheral portion of the protrusion, so that the same protrusion as that of the above-described embodiment is formed. The continuous dot performance is high because the height and diameter of the protrusions are kept constant even if the number of dots is advanced.
【0078】なお、本実施例では、コーン形電極の先端
部は平面部(d3)としたが、この先端部は適宜な曲率
半径を設けた球面としても同様の性能が得られること
は、前述したように言うまでもない。また、コーン形電
極のコーン部は、本実施例では、図10に示したように
正面図で、テーパ面が直線となるような円すい形とした
が、例えば、この直線部分が比較的大きな曲率半径をも
った凸R、または凹Rまたは任意な曲線となる形状とし
てもよい。In this embodiment, the tip of the cone-shaped electrode is a flat surface (d 3 ), but the same performance can be obtained even if the tip is a spherical surface provided with an appropriate radius of curvature. Needless to say, as mentioned above. Further, in the present embodiment, the cone portion of the cone-shaped electrode has a conical shape in which the tapered surface is a straight line in the front view as shown in FIG. 10. However, for example, this straight line portion has a relatively large curvature. The shape may be a convex R having a radius, a concave R, or an arbitrary curved line.
【0079】[0079]
【発明の効果】本発明に係わるアルミニウム系被溶接材
料の抵抗スポット溶接用電極は、請求項1に記載してい
るように、アルミニウム系被溶接材料の抵抗スポット溶
接に用いる電極において、電極の電気伝導度が97IA
CS%以上で、かつ、200℃以下ではビッカース硬さ
Hv80以上、400℃以上ではビッカース硬さHv3
0以下となるように、200℃から400℃の間でビッ
カース硬さがHv80以上からHv30以下に軟化する
高温硬度特性を有する材料を用いてなるものとしたか
ら、電極材料の電気伝導度と、高温での被溶接材料に対
する硬度特性がアルミニウム系被溶接材料の抵抗スポッ
ト溶接にとって最適化されたものとなり、すなわち、電
極に、被溶接材料であるアルミニウム合金の軟化特性に
あわせた高温硬度特性、つまり、特定温度域における軟
化特性をもたせることとなるので、電極先端の形状を特
定の形状とすることにより連続打点において電極先端の
接触径を一定に保つことが可能となり、つまり、溶接時
の電流密度を一定に保つことが可能となり、鋼板並みの
連続打点性と溶接部の良好なる外観品質を得ることが可
能となって、アルミニウム系被溶接材料の抵抗スポット
溶接に際して従来のような電極寿命が短くかつまた溶接
部の外観品質が低下するという問題点が解消されること
となるという著しく優れた効果がもたらされる。As described in claim 1, the electrode for resistance spot welding of the aluminum-based material to be welded according to the present invention is used in the resistance spot welding of the aluminum-based material to be welded. Conductivity is 97IA
Vickers hardness Hv80 or more at CS% or more and 200 ° C. or less, Vickers hardness Hv3 at 400 ° C. or more
Since the Vickers hardness is softened from Hv80 or more to Hv30 or less between 200 ° C. and 400 ° C. so as to be 0 or less, the electrical conductivity of the electrode material, The hardness characteristics for the material to be welded at high temperature will be optimized for resistance spot welding of the aluminum-based material to be welded, that is, for the electrode, the high-temperature hardness characteristics that match the softening characteristics of the aluminum alloy that is the material to be welded, that is, Since it has softening characteristics in a specific temperature range, by making the shape of the electrode tip a specific shape, it is possible to keep the contact diameter of the electrode tip constant at continuous welding points, that is, the current density during welding. Can be maintained at a constant level, and it is possible to obtain continuous spotting properties similar to steel plates and good appearance quality of welded parts. Electrode life and reduced as in the conventional during the resistance spot welding um based welded material also appearance quality of the weld results in significantly better effect becomes to be solved is deteriorated.
【0080】そして、本発明に係わるアルミニウム系被
溶接材料の抵抗スポット溶接用電極の実施態様において
は、請求項2に記載しているように、電極先端の形状が
電極先端にR8mm〜R40mmの曲率半径をもつR形
であって、かつ、被溶接材料の薄板側の板厚をtmmと
したときに、そのR形状の部分が少なくとも直径で6√
tmm以上確保されているものとすることによって、電
極先端に突起が容易に形成され、かつ打点数が進んでも
その突起が良好に維持されることが可能となって、突起
消滅打点数を大幅に増大させることが可能となり、連続
打点性能に優れたアルミニウム系被溶接材料の抵抗スポ
ット溶接用電極を得ることが可能であるという著しく優
れた効果がもたらされる。In the embodiment of the resistance spot welding electrode of the aluminum-based material to be welded according to the present invention, as described in claim 2, the shape of the electrode tip has a curvature of R8 mm to R40 mm at the electrode tip. When it is R-shaped with a radius and the thickness of the thin plate side of the material to be welded is tmm, the R-shaped part is at least 6√ in diameter.
By ensuring tmm or more, it becomes possible to easily form protrusions at the electrode tips and to maintain the protrusions well even if the number of dots is advanced, and to significantly increase the number of dots to be extinguished. It is possible to increase the number of electrodes, and it is possible to obtain a resistance spot welding electrode of an aluminum-based material to be welded having excellent continuous spot performance, which is a remarkably excellent effect.
【0081】また、請求項3に記載しているように、電
極先端の形状が被溶接材料の薄板側の板厚をtmmとし
たときに、電極先端に直径4√tmm〜6√tmmの平
面部を有し、かつ、その外周部は曲率半径がR8mm〜
R40mmのR形であるものとすることによって、電極
先端に突起が容易に自己形成されることが可能となり、
かつまた打点が進行してもその突起が良好に維持される
ことが可能となって、突起消滅打点数が大幅に増大し、
連続打点性能に優れたアルミニウム系被溶接材料の抵抗
スポット溶接用電極ととすることが可能であるという著
しく優れた効果がもたらされる。Further, as described in claim 3, when the shape of the electrode tip is tmm and the thickness of the thin plate side of the material to be welded is tmm, a flat surface having a diameter of 4√tmm to 6√tmm is formed at the electrode tip. And the outer periphery has a radius of curvature of R8 mm-
By adopting an R shape of R40 mm, it becomes possible to easily self-form the protrusion at the electrode tip,
Moreover, even if the number of hit points progresses, the protrusions can be maintained well, and the number of hit points that disappears the protrusion greatly increases.
A remarkably excellent effect that it can be used as an electrode for resistance spot welding of an aluminum-based material to be welded having excellent continuous spot performance is brought about.
【0082】あるいは、請求項4に記載しているよう
に、電極先端の形状が電極先端にR8mm〜R40mm
の曲率半径をもつR形であって、かつ、被溶接材料の薄
板側の板厚をtmmとしたときに、そのR形状の先端部
の直径が4√tmm〜6√tmmの範囲にのみ、曲率半
径がその電極の前記曲率半径よりも大きい別の曲率半径
を有した少なくとも二つ以上の複合球面ないしは複合曲
面で構成される形状を有するものとすることによって
も、突起消滅打点数は大幅に増大し、連続打点性能に優
れたアルミニウム系被溶接材料の抵抗スポット溶接用電
極とすることが可能であるという著しく優れた効果がも
たらされる。Alternatively, as described in claim 4, the shape of the electrode tip is R8 mm to R40 mm at the electrode tip.
R-shape having a radius of curvature of, and the thickness of the thin plate side of the material to be welded is tmm, the diameter of the tip of the R-shape is only in the range of 4√tmm to 6√tmm, The number of projection vanishing spots is also significantly increased by having a shape composed of at least two or more compound spherical surfaces or compound curved surfaces having a different radius of curvature larger than the radius of curvature of the electrode. It is possible to obtain a remarkably excellent effect that it can be used as a resistance spot welding electrode of an aluminum-based material to be welded, which is excellent in continuous spotting performance.
【0083】あるいは、請求項5に記載しているよう
に、電極先端の形状が被溶接材料の薄板側の板厚をtm
mとしたときに、電極先端に直径4√tmm〜6√tm
mの平面部を有し、かつ、その外周部は電極の軸芯との
直交軸に対し5°〜30°の角度をもつ略テーパ形状と
した形状を有するものとすることによっても、突起消滅
打点数は大幅に増大し、連続打点性能に優れたアルミニ
ウム系被溶接材料の抵抗スポット溶接用電極とすること
が可能であるという著しく優れた効果がもたらされる。Alternatively, as described in claim 5, the shape of the electrode tip is the thickness tm of the thin plate side of the material to be welded.
When m, the diameter of the electrode tip is 4√tmm to 6√tm
The protrusion disappears also by having a flat portion of m and an outer peripheral portion having a substantially tapered shape with an angle of 5 ° to 30 ° with respect to an axis orthogonal to the axis of the electrode. The number of spots is remarkably increased, which brings about a remarkably excellent effect that the electrode can be used as a resistance spot welding electrode of an aluminum-based material to be welded having excellent continuous spot performance.
【0084】あるいは、請求項6に記載しているよう
に、電極先端の形状が被溶接材料の薄板側の板厚をtm
mとしたときに、電極先端に直径4√tmm〜6√tm
mの範囲にのみ、適宜な曲率半径をもつ球面部を有し、
かつ、その外周部は電極の軸芯との直交軸に対し5°〜
30°の角度をもつ略テーパ形状とした形状を有するも
のとすることによっても、突起消滅打点数は大幅に増大
し、連続打点性能に優れたアルミニウム系被溶接材料の
抵抗スポット溶接用電極とすることが可能であるという
著しく優れた効果がもたらされる。Alternatively, as described in claim 6, the shape of the electrode tip is the thickness tm of the thin plate side of the material to be welded.
When m, the diameter of the electrode tip is 4√tmm to 6√tm
Only in the range of m, there is a spherical portion having an appropriate radius of curvature,
And, the outer peripheral portion is 5 ° to the axis orthogonal to the axis of the electrode.
The resistance spot welding electrode of the aluminum-based material to be welded, which has an excellent number of spots for extinction of protrusions, is also significantly increased by forming a substantially tapered shape having an angle of 30 °. It is possible to obtain a remarkably excellent effect.
【0085】あるいは、請求項7に記載しているよう
に、電極先端の形状が被溶接材料の薄板側の板厚をtm
mとしたときに、電極先端に直径4√tmm〜6√tm
mで、高さ0.1tmm〜0.3tmmとなる突起を設
け、かつ、前記突起の外周部には前記突起の外壁から全
周にわたって少なくとも1mm以上の平坦部を形成した
形状とすることによっても、突起消滅打点数は大幅に増
大し、連続打点性能に優れたアルミニウム系被溶接材料
の抵抗スポット溶接用電極とすることが可能であるとい
う著しく優れた効果がもたらされる。Alternatively, as described in claim 7, the shape of the electrode tip is the thickness tm of the thin plate side of the material to be welded.
When m, the diameter of the electrode tip is 4√tmm to 6√tm
Also, by providing a protrusion having a height of 0.1 tmm to 0.3 tmm in m, and forming a flat portion of at least 1 mm or more over the entire circumference from the outer wall of the protrusion on the outer peripheral portion of the protrusion. In addition, the number of spots for extinction of protrusions is significantly increased, and it is possible to obtain a remarkably excellent effect that the electrode can be used as a resistance spot welding electrode of an aluminum-based material to be welded having excellent continuous spot performance.
【0086】そして、請求項8に記載しているように、
前記突起の角部または外壁部と、平坦部とを適宜な曲率
半径をもつ曲面でつないだ形状とすることによって、ま
た、請求項9に記載しているように、前記突起の先端形
状が平面であるものとすることによって、あるいは、請
求項10に記載しているように、前記突起の先端形状が
適宜な曲率半径を有した球面であるものとすることによ
って、3000打点を超える以上に電極先端の突起が維
持され、連続打点性能が著しく向上したものとなるとい
う顕著な効果がもたらされる。Then, as described in claim 8,
By forming a shape in which a corner portion or an outer wall portion of the projection and a flat portion are connected by a curved surface having an appropriate curvature radius, and as described in claim 9, the tip shape of the projection is a flat surface. Or by setting the tip shape of the projection to be a spherical surface having an appropriate radius of curvature as described in claim 10, The protrusion at the tip is maintained, and the remarkable effect that the continuous dot performance is remarkably improved is brought about.
【0087】さらに、本発明に係わるアルミニウム系被
溶接材料の抵抗スポット溶接方法は、請求項11に記載
しているように、アルミニウム系被溶接材料を抵抗スポ
ット溶接するに際し、電極の電気伝導度が97IACS
%以上で、かつ、電極と被溶接材料との硬度差がビッカ
ース硬さにおいて、200℃以下ではHv20以上であ
り、250℃〜400℃の温度範囲の間ではHv15以
下となるような電極と被溶接材料とを用いて溶接を行う
ようにしたから、電極材料の電気伝導度と、高温での被
溶接材料に対する硬度特性がアルミニウム系被溶接材料
に対する抵抗スポット溶接にとって最適化されたものと
なり、鋼板並みの連続打点性と溶接部の良好なる外観品
質が得ることが可能になるという著しく優れた効果がも
たらされる。Further, according to the resistance spot welding method for an aluminum-based material to be welded according to the present invention, when the aluminum-based material to be welded is resistance spot-welded, the electrical conductivity of the electrode is 97IACS
% And the Vickers hardness difference between the electrode and the material to be welded is Hv20 or more at 200 ° C. or less and Hv15 or less at a temperature range of 250 ° C. to 400 ° C. Since the welding is performed using the welding material, the electrical conductivity of the electrode material and the hardness characteristics of the welding material at high temperature are optimized for resistance spot welding of the aluminum welding material. It is possible to obtain a remarkably excellent continuous spotting property and a good appearance quality of the welded portion.
【0088】そして、本発明に係わるアルミニウム系被
溶接材料の抵抗スポット溶接用電極および抵抗スポット
溶接方法の実施態様においては、請求項12に記載して
いるように、電極の材質がタフピッチ銅であるものとす
ることによって、また、請求項13に記載しているよう
に、電極の材質が無酸素銅であるものとすることによっ
て、入手の容易な電極材料を用いて連続打点性能に優れ
たアルミニウム系被溶接材料の抵抗スポット溶接用電極
にすることが可能であると共に、溶接部の良好なる外観
を得ることが可能になるという著しく優れた効果がもた
らされる。In an embodiment of the resistance spot welding electrode and the resistance spot welding method for an aluminum-based material to be welded according to the present invention, as described in claim 12, the material of the electrode is tough pitch copper. In addition, as described in claim 13, the material of the electrode is oxygen-free copper, so that aluminum having excellent continuous dot performance using an easily available electrode material can be used. It is possible to obtain an electrode for resistance spot welding of the material to be welded, and it is possible to obtain a good appearance of the welded part, which is a remarkably excellent effect.
【図1】本発明の一実施例による抵抗スポット溶接用電
極と、従来例1の抵抗スポット溶接用電極および被溶接
材料の温度−硬さ特性を示すグラフである。FIG. 1 is a graph showing temperature-hardness characteristics of a resistance spot welding electrode according to an embodiment of the present invention, a resistance spot welding electrode of Conventional Example 1 and a material to be welded.
【図2】図2(A)は本発明の一実施例による抵抗スポ
ット溶接用電極の初期形状を示し、図2(B)は連続打
点途中の電極形状を示し、図2(C)は劣化変形した従
来電極の形状を示すそれぞれ模式図である。FIG. 2 (A) shows an initial shape of an electrode for resistance spot welding according to an embodiment of the present invention, FIG. 2 (B) shows an electrode shape in the middle of continuous welding, and FIG. 2 (C) shows deterioration. It is each a schematic diagram which shows the shape of the modified conventional electrode.
【図3】本発明の一実施例ならびに従来例1,3による
抵抗スポット溶接用電極の連続打点試験中の接触径の推
移を示すグラフである。FIG. 3 is a graph showing a transition of a contact diameter of a resistance spot welding electrode according to an example of the present invention and conventional examples 1 and 3 during a continuous spot test.
【図4】本発明の一実施例による電極での連続打点試験
中のナゲット径の推移を示すグラフである。FIG. 4 is a graph showing a transition of a nugget diameter during a continuous spot test with an electrode according to an example of the present invention.
【図5】本発明の第2の実施例による電極形状とした場
合の連続打点性能を示すグラフである。FIG. 5 is a graph showing continuous dot performance when an electrode shape according to a second embodiment of the present invention is used.
【図6】本発明の第2の実施例による電極の接触径を示
す説明図である。FIG. 6 is an explanatory diagram showing a contact diameter of an electrode according to a second embodiment of the present invention.
【図7】本発明の第3の実施例による電極形状とした場
合の連続打点性能を示すグラフである。FIG. 7 is a graph showing continuous dot performance when an electrode shape according to a third embodiment of the present invention is used.
【図8】図8(A)(B)(C)は本発明の第3の実施
例による電極形状を示す模式図である。8 (A), (B) and (C) are schematic diagrams showing electrode shapes according to a third embodiment of the present invention.
【図9】図9(A)(B)は本発明の第3の実施例によ
る電極形状を示す模式図である。9 (A) and 9 (B) are schematic diagrams showing an electrode shape according to a third embodiment of the present invention.
【図10】本発明の第4の実施例による電極形状を示す
模式図である。FIG. 10 is a schematic diagram showing an electrode shape according to a fourth embodiment of the present invention.
【図11】本発明の第4の実施例による電極形状とした
場合の連続打点性能を示すグラフである。FIG. 11 is a graph showing continuous dot performance when an electrode shape according to a fourth embodiment of the present invention is used.
1 電極 1a 電極先端の突起 1b 突起外周部の平坦部 1c 電極先端の外径部 1d 電極先端の平面部 1e 電極先端の平坦部 1f 電極先端のコーン部 2 円形打痕 3 三日月形打痕 DESCRIPTION OF SYMBOLS 1 electrode 1a protrusion of electrode tip 1b flat portion of outer periphery of protrusion 1c outer diameter portion of electrode tip 1d flat portion of electrode tip 1e flat portion of electrode tip 1f cone portion of electrode tip 2 circular dent 3 crescent-shaped dent 3
Claims (13)
ト溶接に用いる電極において、電極の電気伝導度が97
IACS%以上で、かつ、200℃以下ではビッカース
硬さHv80以上、400℃以上ではビッカース硬さH
v30以下となるように、200℃から400℃の間で
ビッカース硬さがHv80以上からHv30以下に軟化
する高温硬度特性を有する材料を用いてなることを特徴
とするアルミニウム系被溶接材料の抵抗スポット溶接用
電極。1. An electrode used for resistance spot welding of an aluminum-based material to be welded has an electric conductivity of 97.
Vickers hardness Hv80 or more at IACS% or more and 200 ° C or less, Vickers hardness H at 400 ° C or more
A resistance spot of an aluminum-based material to be welded, characterized by using a material having a high-temperature hardness characteristic that the Vickers hardness is softened from Hv80 or more to Hv30 or less between 200 ° C and 400 ° C so as to be v30 or less. Welding electrode.
R40mmの曲率半径をもつR形であって、かつ、被溶
接材料の薄板側の板厚をtmmとしたときに、そのR形
状の部分が少なくとも直径で6√tmm以上確保されて
いることを特徴とする請求項1に記載のアルミニウム系
被溶接材料の抵抗スポット溶接用電極。2. The shape of the electrode tip is R8 mm to the electrode tip.
It is R-shaped with a radius of curvature of R40mm, and when the thickness of the thin plate side of the material to be welded is tmm, the R-shaped portion is at least 6√tmm in diameter. An electrode for resistance spot welding of the aluminum-based material to be welded according to claim 1.
板厚をtmmとしたときに、電極先端に直径4√tmm
〜6√tmmの平面部を有し、かつ、その外周部は曲率
半径がR8mm〜R40mmのR形であることを特徴と
する請求項1に記載のアルミニウム系被溶接材料の抵抗
スポット溶接用電極。3. When the shape of the electrode tip is tmm and the thickness of the thin plate side of the material to be welded is tmm, the diameter of the electrode tip is 4√tmm.
The electrode for resistance spot welding of an aluminum-based material to be welded according to claim 1, wherein the electrode has a flat surface portion of ˜6√tmm and an outer peripheral portion thereof is an R shape having a radius of curvature of R8 mm to R40 mm. .
R40mmの曲率半径をもつR形であって、かつ、被溶
接材料の薄板側の板厚をtmmとしたときに、そのR形
状の先端部の直径が4√tmm〜6√tmmの範囲にの
み、曲率半径がその電極の前記曲率半径よりも大きい別
の曲率半径を有した少なくとも二つ以上の複合球面ない
しは複合曲面で構成される形状を有することを特徴とす
る請求項1に記載のアルミニウム系被溶接材料の抵抗ス
ポット溶接用電極。4. The shape of the electrode tip is R8 mm to the electrode tip.
R-type with a radius of curvature of R40 mm, and when the thickness of the thin plate side of the material to be welded is tmm, the diameter of the tip of the R-shape is only within the range of 4√tmm to 6√tmm. The aluminum system according to claim 1, wherein the aluminum system has a shape composed of at least two or more compound spherical surfaces or compound curved surfaces each having a different radius of curvature larger than the radius of curvature of the electrode. Electrodes for resistance spot welding of materials to be welded.
板厚をtmmとしたときに、電極先端に直径4√tmm
〜6√tmmの平面部を有し、かつ、その外周部は電極
の軸芯との直交軸に対し5°〜30°の角度をもつ略テ
ーパ形状としたことを特徴とする請求項1に記載のアル
ミニウム系被溶接材料の抵抗スポット溶接用電極。5. The diameter of the electrode tip is 4√tmm when the shape of the electrode tip is tmm and the thickness of the thin plate side of the material to be welded is tmm.
2. A flat portion having a size of ˜6√tmm, and an outer peripheral portion thereof having a substantially taper shape having an angle of 5 ° to 30 ° with respect to an axis orthogonal to the axis of the electrode. An electrode for resistance spot welding of the described aluminum-based material to be welded.
板厚をtmmとしたときに、電極先端に直径4√tmm
〜6√tmmの範囲にのみ、適宜な曲率半径をもつ球面
部を有し、かつ、その外周部は電極の軸芯との直交軸に
対し5°〜30°の角度をもつ略テーパ形状としたこと
を特徴とする請求項1に記載のアルミニウム系被溶接材
料の抵抗スポット溶接用電極。6. The diameter of the electrode tip is 4√tmm when the thickness of the electrode tip is tmm when the thin plate side of the material to be welded is tmm.
A spherical portion having an appropriate radius of curvature only in the range of up to 6√tmm, and its outer peripheral portion has a substantially tapered shape having an angle of 5 ° to 30 ° with respect to an axis orthogonal to the axis of the electrode. The resistance spot welding electrode of the aluminum-based material to be welded according to claim 1, wherein
板厚をtmmとしたときに、電極先端に直径4√tmm
〜6√tmmで、高さ0.1tmm〜0.3tmmとな
る突起を設け、かつ、前記突起の外周部には前記突起の
外壁から全周にわたって少なくとも1mm以上の平坦部
を形成した形状としたことを特徴とする請求項1に記載
のアルミニウム系被溶接材料の抵抗スポット溶接用電
極。7. The diameter of the electrode tip is 4√tmm when the thickness of the electrode tip is tmm when the thickness of the thin plate of the material to be welded is tmm.
A protrusion having a height of 0.1 tmm to 0.3 tmm and a flat portion of at least 1 mm or more is formed on the outer peripheral portion of the protrusion from the outer wall of the protrusion to the entire circumference. The electrode for resistance spot welding of the aluminum-based material to be welded according to claim 1.
適宜な曲率半径をもつ曲面でつないだ形状としたことを
特徴とする請求項7に記載のアルミニウム系被溶接材料
の抵抗スポット溶接用電極。8. The resistance spot of the aluminum-based material to be welded according to claim 7, wherein a corner portion or outer wall portion of the protrusion and a flat portion are connected by a curved surface having an appropriate radius of curvature. Welding electrode.
とする請求項7または請求項8に記載のアルミニウム系
被溶接材料の抵抗スポット溶接用電極。9. The resistance spot welding electrode for an aluminum-based material to be welded according to claim 7, wherein the projection has a flat tip shape.
した球面であることを特徴とする請求項7または請求項
8に記載のアルミニウム系被溶接材料の抵抗スポット溶
接用電極。10. The electrode for resistance spot welding of an aluminum-based material to be welded according to claim 7, wherein the tip shape of the protrusion is a spherical surface having an appropriate radius of curvature.
ット溶接するに際し、電極の電気伝導度が97IACS
%以上で、かつ、電極と被溶接材料との硬度差がビッカ
ース硬さにおいて、200℃以下ではHv20以上であ
り、250℃〜400℃の温度範囲の間ではHv15以
下となるような電極と被溶接材料とを用いて溶接を行う
ことを特徴とするアルミニウム系被溶接材料の抵抗スポ
ット溶接方法。11. An electrode having an electric conductivity of 97 IACS when resistance spot welding an aluminum-based material to be welded.
% And the Vickers hardness difference between the electrode and the material to be welded is Hv20 or more at 200 ° C. or less and Hv15 or less at a temperature range of 250 ° C. to 400 ° C. A resistance spot welding method for an aluminum-based material to be welded, which comprises performing welding using the welding material.
を特徴とする請求項1または請求項11に記載のアルミ
ニウム系被溶接材料の抵抗スポット溶接用電極および抵
抗スポット溶接方法。12. The resistance spot welding electrode and the resistance spot welding method for an aluminum-based material to be welded according to claim 1 or 11, wherein the material of the electrode is tough pitch copper.
徴とする請求項1または請求項11に記載のアルミニウ
ム系被溶接材料の抵抗スポット溶接用電極および抵抗ス
ポット溶接方法。13. The electrode for resistance spot welding of an aluminum-based material to be welded and the resistance spot welding method according to claim 1, wherein the material of the electrode is oxygen-free copper.
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP7225572A JPH0966370A (en) | 1995-09-01 | 1995-09-01 | Electrode for resistance spot welding to aluminum material to be welded and resistance spot welding method |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP7225572A JPH0966370A (en) | 1995-09-01 | 1995-09-01 | Electrode for resistance spot welding to aluminum material to be welded and resistance spot welding method |
Publications (1)
Publication Number | Publication Date |
---|---|
JPH0966370A true JPH0966370A (en) | 1997-03-11 |
Family
ID=16831415
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
JP7225572A Pending JPH0966370A (en) | 1995-09-01 | 1995-09-01 | Electrode for resistance spot welding to aluminum material to be welded and resistance spot welding method |
Country Status (1)
Country | Link |
---|---|
JP (1) | JPH0966370A (en) |
Cited By (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP2006130514A (en) * | 2004-11-02 | 2006-05-25 | Nisshin Steel Co Ltd | Electrode for spot welding |
JP2006198676A (en) * | 2004-12-24 | 2006-08-03 | Daihatsu Motor Co Ltd | Electrode for resistance welding and series spot welding equipment or indirect spot welding equipment |
KR100740587B1 (en) * | 2005-12-26 | 2007-07-18 | 주식회사 나래나노텍 | Improved Electrode Tip Device |
JP2007307588A (en) * | 2006-05-18 | 2007-11-29 | Honda Motor Co Ltd | Electrode for spot welding |
JP2019048313A (en) * | 2017-09-11 | 2019-03-28 | 積水化学工業株式会社 | Spot welding electrode, welding device and welding method |
-
1995
- 1995-09-01 JP JP7225572A patent/JPH0966370A/en active Pending
Cited By (6)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP2006130514A (en) * | 2004-11-02 | 2006-05-25 | Nisshin Steel Co Ltd | Electrode for spot welding |
JP4521756B2 (en) * | 2004-11-02 | 2010-08-11 | 日新製鋼株式会社 | Spot welding electrode |
JP2006198676A (en) * | 2004-12-24 | 2006-08-03 | Daihatsu Motor Co Ltd | Electrode for resistance welding and series spot welding equipment or indirect spot welding equipment |
KR100740587B1 (en) * | 2005-12-26 | 2007-07-18 | 주식회사 나래나노텍 | Improved Electrode Tip Device |
JP2007307588A (en) * | 2006-05-18 | 2007-11-29 | Honda Motor Co Ltd | Electrode for spot welding |
JP2019048313A (en) * | 2017-09-11 | 2019-03-28 | 積水化学工業株式会社 | Spot welding electrode, welding device and welding method |
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