【発明の詳細な説明】[Detailed description of the invention]
本発明は金属薄帯の突合せ溶接方法に係り、詳
しくは、金属薄板の端部を切断後、その切断面を
正確に溶接線に合せて突合せることができ、レー
ザ溶接であつても支障なく突合せ溶接できる溶接
方法に係る。
急冷薄帯を含めた金属薄帯を突合せ溶接する際
に、目違いの発生を防ぐためにできるだけ溶接線
の近傍をクランプすることが行なわれている。し
かし、板形状（平坦度など）が悪い場合には目違
いや溶接線の裏当金からの浮き上がりを防ぐこと
ができない。
従来、金属薄帯の溶接では突合せ継手でTIG、
プラズマ溶接が若干使われているが、多くは重ね
継手であるシーム溶接が用いられ、EBW、
LASERでも重ね継手としての用法がほとんどで
ある。
突合せ継手が用いられにくいのは溶接線での目
違い、間隙の生じ易さにあり、これらはいずれも
溶接ビート欠陥に結びつくからである。
この点、開先間隙は薄帯を切るシエアの刃の直
線性や、クリアランス調整によつて適正範囲内に
納めることはできる。しかし、板形状が非常に悪
い急冷薄帯などでは第１図に示すような従来のク
ランプ装置では目違いや溶接線の浮上りを防ぐこ
とは出来ない。なお、このクランプ装置は一対の
金属薄板２ａ，２ｂを突合せてクランプ片１によ
つて押さえ、突合せ線に沿つて溶接トーチ（図示
せず）が移動して溶接されるものである。
この点から、薄板の突合せ時に薄板を突合せる
方向と直交方向、すなわち突合せ線３が湾曲する
ようにして薄板２ａ，２ｂに剛性を与えてクラン
プ語１によりクランプし、突合せ溶接を容易にす
る方法が特開昭57−1571号公報に記載される如く
提案されている。この方法は前述の欠点を除く方
法の一つであるが、突合せ線３が溶接方向に湾曲
しているため、レーザ溶接のように溶接点と焦点
との相対的位置関係が厳しく規制されるような溶
接方法ではレーザビーム焦点位置を溶接中にアル
タイムで制御する必要があり、これに用いられる
溶接機も高価なものになる。また、この方法では
裏当金を使用しても突合せ線近傍で裏当金に垂直
方向の力が働いていないために、突合せ部と裏当
金間に間隙を生じやすく、その間隙によつて溶接
部に孔状の欠陥等が誘起される。
本発明は上記欠点の解決を目的とし、金属薄帯
の突合せ溶接時に、突合せ線の裏当金からの浮上
りを完全に防止でき、容易に突合せ溶接する方法
を提案する。
すなわち、本発明方法は突合せるべき一対の金
属薄帯の端部をその巾方向に切断してから裏当金
上においてこれら切断端面を支点として各金属薄
帯の端部を湾曲させた後、切断端面を突合わせ、
その突合せ線を溶接線と一致させて溶接すること
を特徴とする。
まず、本発明法においては一対の金属薄帯を溶
接ビートと溶着しない裏当金を用いて突合せ溶接
する際に、そのまま金属薄帯（以下、薄帯とい
う。）の端面を突合せることなく、被溶接材たる
両薄帯同士を突合せ端面、つやり突合せ線を支点
として湾曲させて突合わせ溶接する。
すなわち、第３図に示す如く、溶接に先立つて
２ａの巾方向に切断し、この直線状に切断された
端面２a′を例えば裏当金５等の固体平面に密着さ
せ、薄帯が塑性変形を起こさない範囲で、端面２
a′若しくはその近傍を支点として曲げ変形を加え
ると、端面上のどの点をとつても裏当金５等の固
体平面に押し付ける方向に力が働き、端面２a′の
裏当金５等の固体平面上への密着が保証されるこ
とになる。なお、この点につき、第２図の如く剛
性を持たせるために薄帯２ａ，２ｂ等をその長手
方向に湾曲される例が示されているが、この場合
の突合せ端面が円弧になり、平坦な裏当金が使用
できないほか、たとえ円弧状に合わせた当金を用
いても、本発明法の如く突合せ端面を当金に押付
ける力が働かない。
そこで、第４図ａ，ｂならびにｃによつて本発
明法について更に詳しく説明すると、次の通りで
ある。
すなわち、第４図ａ，ｂならびにｃは本発明方
法による突合せ態様の一例の各過程の説明であつ
て、とくに突合せ部近傍を示したものである。ま
ず、溶接に先立つて、一対の薄帯２ａ，２ｂの各
端部を切断し、その切断端面を第４図ａの如く裏
合金上で切断端面２a′，２b′を支点として薄帯２
ａ，２ｂを湾曲させる。その後、一方の薄帯２ａ
をクランプ１とともに裏当金５上をスライドさ
せ、溶接線４に薄帯の端面２a′を一致させる（第
４図ｂ参照）。続いて、他方の薄帯２ｂをクラン
プ１とともに裏当金５上においてスライドさせ、
第４図ｃのように薄帯２ｂの端面２b′を溶接線４
と一致させ、溶接線４と突合せ線とを一致させ
る。なお、このように溶接線と突合せ線と一致さ
せた後は、溶接線に沿つて溶接する。この場合、
何れの方法で溶接することもできるが、溶接線と
突合せ線とが正確に一致していることもあつて、
レーザ溶接で良好に溶接できる。
以上の通りに突合せを行なうと、溶接端は確実
に裏当金に当るために溶接時に突合せ開先が裏当
金から浮上することがなく、当然、裏当金からの
浮上によつて生ずるビードの孔あき等の欠陥は発
生しない。
また、本発明方法は何れの態様によつても実施
できるが、第５図ａ，ｂ，ｃならびにｄに示す装
置を用いると、連続かつ自動的に実施できる。
すなわち、第５図ａ，ｂ，ｃならびにｄは本発
明方法を実施する装置のクランプの動作の継時的
説明図であつて、第５図ａはシヤー（図示せず）
により一対の薄帯を切断し、そのシヤーが待期位
置に退避した後の先、後行薄帯の切断端部を示
す。
シヤーが退避した後、裏当金５が挿入され、同
時に補助クランプ１ｃ，１ｄのうち下側補助クラ
ンプ１ｄが下降すると共に、先、後行側何れか一
方の主、従クランプ１ａ，１ｂが前進し、その後
薄帯２ａ，２ｂの切断端面若しくは端部を裏当金
５に押しつけ得る位置で停止する（第５図ｂ参
照）。しかる後、上側補助クランプ１ｃが傾動
し、薄帯２ａ，２ｂを裏当金５に押しつけ（第５
図ｃ参照）、更に、先に前進した可動クランプが
前進して突合せを完了させる（第５図ｄ参照）。
以上のような操作で得た突合せ部は各薄帯端部
が裏当金に密着しているため、目違いを生じるこ
とがない。
本発明法によると、板形状不良の急冷薄帯でも
突合せ溶接が可能となり、形状制御のための圧延
を効率的に行なえる結果、金属薄帯の生産性が大
巾に向上する。
次に、実施例について説明する。
先行、後行の急冷金属薄帯の対向端部を切断
し、これら端面を従来例によりクランプに突合せ
てレーザ溶接する一方、本発明法によりクランプ
に突合せてレーザ溶接を行なつた。
この結果は第１表に示す。
The present invention relates to a method for butt welding thin metal strips, and more specifically, after cutting the end of a thin metal sheet, the cut surfaces can be butted together accurately in line with the welding line, and there is no problem even with laser welding. This relates to a welding method that allows butt welding. When butt welding metal ribbons including quenched ribbons, clamping is performed as close to the weld line as possible to prevent misalignment. However, if the plate shape (flatness, etc.) is poor, it is not possible to prevent misalignment or lifting of the weld line from the backing metal. Traditionally, butt joints were welded using TIG,
Plasma welding is used to some extent, but seam welding, which is a lap joint, is mostly used, and EBW,
LASER is also mostly used as a lap joint. Butt joints are difficult to use because of the ease with which weld lines are misaligned and gaps are formed, both of which lead to weld beat defects. In this regard, the groove gap can be kept within an appropriate range by adjusting the linearity of the shear blade that cuts the ribbon and adjusting the clearance. However, for quenched ribbons with extremely poor plate shapes, the conventional clamping device shown in FIG. 1 cannot prevent misalignment or lifting of the weld line. In this clamp device, a pair of thin metal plates 2a and 2b are butted together and held together by a clamp piece 1, and a welding torch (not shown) is moved along the butt line to perform welding. From this point of view, there is a method of making butt welding easier by giving rigidity to the thin plates 2a and 2b by curving the butt line 3 in a direction perpendicular to the direction in which the thin plates are butted, that is, when the thin plates are butted, and clamping them using the clamp word 1. has been proposed as described in Japanese Unexamined Patent Publication No. 1571/1983. This method is one of the methods to eliminate the above-mentioned drawbacks, but since the butt line 3 is curved in the welding direction, the relative positional relationship between the welding point and the focal point is strictly regulated as in laser welding. In such a welding method, it is necessary to control the laser beam focal position in real time during welding, and the welding machine used for this also becomes expensive. In addition, in this method, even if a backing metal is used, there is no vertical force acting on the backing metal near the butt line, so a gap is likely to occur between the butt part and the backing metal, and this gap can cause Hole-like defects etc. are induced in the weld. The present invention aims to solve the above-mentioned drawbacks and proposes a method that can completely prevent the butt wire from floating up from the backing metal during butt welding of metal ribbons, and can easily butt weld the weld. That is, in the method of the present invention, the ends of a pair of thin metal strips to be butted are cut in the width direction, and then the ends of each thin metal strip are curved on the backing metal using the cut end surfaces as fulcrums. Butt the cut ends together,
The welding is performed by aligning the butt line with the welding line. First, in the method of the present invention, when butt welding a pair of metal ribbons using a backing metal that does not weld to the welding beat, the end faces of the metal ribbons (hereinafter referred to as ribbons) are not butted together. Both thin strips, which are the materials to be welded, are butt-welded by butt-welding their end faces together and bending the polished butt line as a fulcrum. That is, as shown in FIG. 3, prior to welding, the ribbon 2a is cut in the width direction, and the linearly cut end surface 2a' is brought into close contact with a solid flat surface such as a backing metal 5, so that the ribbon is plastically deformed. End face 2 within a range that does not cause
When bending deformation is applied using a' or its vicinity as a fulcrum, a force acts in the direction of pressing any point on the end face against a solid flat surface such as the backing metal 5, etc. on the end face 2a'. Adhesion to a flat surface is guaranteed. Regarding this point, an example is shown in which the ribbons 2a, 2b, etc. are curved in the longitudinal direction in order to provide rigidity as shown in Fig. 2, but in this case, the butt end faces are arcuate and flat. In addition, even if an arc-shaped backing metal is used, the force that presses the abutting end face against the metal will not work as in the method of the present invention. Therefore, the method of the present invention will be explained in more detail with reference to FIGS. 4a, b, and c as follows. That is, FIGS. 4a, 4b, and 4c are explanations of each process of an example of the butting aspect according to the method of the present invention, and particularly show the vicinity of the butting portion. First, prior to welding, each end of the pair of thin ribbons 2a and 2b is cut, and the cut end surfaces are placed on the back alloy as shown in FIG.
Curve a and 2b. After that, one thin strip 2a
is slid on the backing metal 5 together with the clamp 1, so that the end surface 2a' of the ribbon is aligned with the weld line 4 (see FIG. 4b). Next, slide the other thin strip 2b together with the clamp 1 on the backing metal 5,
As shown in Fig. 4c, the end surface 2b' of the ribbon 2b is
The weld line 4 and the butt line are made to match. Note that, after the welding line and the butt line are aligned in this way, welding is performed along the welding line. in this case,
Welding can be done using either method, but as long as the weld line and butt line match exactly,
Can be successfully welded by laser welding. When butt is performed as described above, the welding end will surely contact the backing metal, so the butt groove will not float up from the backing metal during welding, and naturally, the bead that is generated due to floating from the backing metal. Defects such as holes do not occur. Although the method of the present invention can be carried out in any embodiment, it can be carried out continuously and automatically using the apparatus shown in FIGS. 5a, b, c, and d. That is, FIGS. 5a, b, c, and d are sequential illustrations of the operation of the clamp of the apparatus for implementing the method of the present invention, and FIG. 5a is a shear (not shown).
shows the cut ends of the leading and trailing ribbons after the shear has retracted to the waiting position. After the shear is retracted, the backing metal 5 is inserted, and at the same time, the lower auxiliary clamp 1d of the auxiliary clamps 1c and 1d is lowered, and the main and slave clamps 1a and 1b on either the leading or trailing side move forward. Thereafter, the thin strips 2a, 2b are stopped at a position where the cut end surfaces or ends thereof can be pressed against the backing metal 5 (see FIG. 5b). After that, the upper auxiliary clamp 1c tilts and presses the thin strips 2a and 2b against the backing metal 5 (the fifth
Furthermore, the movable clamp that has advanced first moves forward to complete the butt (see FIG. 5d). In the abutted portion obtained by the above operation, each ribbon end is in close contact with the backing metal, so there is no misalignment. According to the method of the present invention, it is possible to butt weld even rapidly cooled ribbons with poor sheet shapes, and rolling for shape control can be performed efficiently, resulting in a significant improvement in the productivity of metal ribbons. Next, examples will be described. Opposite ends of the leading and trailing quenched metal ribbons were cut, and these end faces were abutted against a clamp and laser welded using the conventional method, while laser welding was performed against the clamp using the method of the present invention. The results are shown in Table 1.
【表】
欠陥の数を示す。
この際の供試急冷薄帯は高珪素鋼の板厚150μ
ｍ、板巾100mmで、何れもレーザ出力800W、速度
３ｍ／分で焦点外し溶接を行なつた。第１表に示
すように、従来法によるクランプでは目違い、あ
るいは突合せ部が裏当金から浮上がるため、ビー
ドに穴があくのに対して、本発明法によるクラン
プでは健全なビードが得られた。[Table] Shows the number of defects.
The sample quenched ribbon was made of high-silicon steel with a thickness of 150 μm.
Defocus welding was performed at a laser output of 800 W and a speed of 3 m/min. As shown in Table 1, with the clamp using the conventional method, a hole is formed in the bead due to misalignment or because the abutting part rises from the backing metal, whereas with the clamp using the present invention, a sound bead is obtained. Ta.
【図面の簡単な説明】[Brief explanation of the drawing]
第１図は従来例に係る溶接時の金属薄帯のクラ
ンプ法態様の一例の説明図、第２図は従来の他の
例の突合せ方法の説明図、第３図は本発明方法の
突合せ原理の説明図、第４図ａ，ｂならびにｃは
本発明法による突合せ態様の一例の各過程の説明
図、第５図ａ，ｂ，ｃならびにｄは本発明方法を
実施する装置の一例の作動態様の各説明図であ
る。
符号、１，１ａ〜１ｄ……クランプ、２ａ，２
ｂ……金属薄帯、３……突合せ線、４……溶接
線、５……裏当金。
Fig. 1 is an explanatory diagram of an example of a conventional clamping method for metal ribbons during welding, Fig. 2 is an explanatory diagram of another conventional butting method, and Fig. 3 is the butting principle of the present invention method. FIGS. 4a, b, and c are explanatory diagrams of each process of an example of the matching mode according to the method of the present invention. FIGS. It is each explanatory drawing of an aspect. Code, 1, 1a to 1d... Clamp, 2a, 2
b...Metal thin strip, 3...Butt line, 4...Welding line, 5...Backing metal.