JP2008105056A - Tig welding method, and equipment therefor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a TIG welding method and equipment therefor where, when carrying out TIG welding, the radiation shape of a welding arc 8 is controlled; thus, even when there is a gap between the parts 10 to be joined, molten metal 9 can be continuously joined to each other. <P>SOLUTION: The radiation shape of a welding arc 8 generated between an electrode 4 in a welding torch 3 connected with the negative pole of a TIG welding machine 2 and the object 5 to be joined connected with the positive pole is deviated by Lorentz force of a fixed magnetic field generated by a permanent magnet 7 arranged at a position parallel to the welding arc 8 so as to obtain a desired oval radiation face shape in the welding line direction of the part 10 to be joined; thus heat input in the welding line direction is increased; the momentum of the deviated welding arc 8 is applied to the generated molten metal in the welding line direction, and action force of pressing the molten metal in the welding line direction is generated so as to continuously join the molten metals 9 of the adjacent parts 10 to be joined with each other while having two gaps. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  In the present invention, when TIG welding is performed to join two joints such as conductor terminals that are arranged with a gap between each other, a welding part that continuously joins the two joints by controlling the welding arc is provided. The present invention relates to a TIG welding method and an apparatus therefor.

[Conventional technology]
Conventionally, as a joining method between conductor terminals, a TIG welding method in which conductor terminals are melted and joined by arc discharge has been used. When the conductor terminal is welded by this TIG welding method, the joined portion corresponding to one end of the conductor terminal is melted by arc discharge. At this time, a flat spherical metal melt is generated in the welded portion of the conductor terminal, and when the two welded portions are adjacent to each other without a gap, the flat spherical metal melt is connected to each other and cooled. As a result, welding is continuously performed between the conductor terminals (see, for example, Patent Document 1).

[Problems with conventional technology]
However, as shown in FIG. 3, when the gap in the weld line direction between the two conductor terminals 111 to be joined is so large that it cannot be ignored, when welding this by arc discharge, the joined portions 110 of the respective conductor terminals 111 are joined. Therefore, there is a possibility that the molten metal 109 that melts independently is generated, and welding that is continuously joined to each other in the weld line direction is not performed. That is, the two conductor terminals 111 are melted and separated only by being melted independently of each other, so that welding that is not continuously joined is performed.
JP 2000-218366 A

  When the gap between two conductor terminals to be joined is large, or when welding a workpiece having a structure in which chamfering or the like is processed in the joint portion of the conductor terminal to create a large gap between the joint portions, molten metal It is desired to provide a TIG welding method and apparatus capable of continuously joining molten metals.

  The present invention has been made in view of the above problems, and when TIG welding is performed, the molten metal melts are continuously joined to each other even if there is a gap between the joined parts by controlling the radial shape of the welding arc. It is an object of the present invention to provide a TIG welding method and apparatus that can be used.

[Means of Claim 1]
In the TIG welding method employing the means of claim 1, the object to be joined includes a part to be joined that is melted and joined to one end in the longitudinal direction, and the two parts to be joined are arranged with a gap between them. This is a conductor terminal in which the direction of the welding line is the direction of the welding line, and an arc discharge is generated between the work piece and the electrode of the welding torch to generate a welding arc, and a constant magnetic field is applied around the welding arc. The electromagnetic force generated by the electromagnetic interaction between the magnetic field and the arc current flowing in the welding arc is applied to the welding arc, and the radial shape of the welding arc is deflected in the weld line direction of the welded portion. It is characterized by performing welding to continuously join the parts.

  As a result, the welding arc deflected by the electromagnetic force generated by the electromagnetic interaction between the magnetic field and the arc current generates a large welding line direction component force of the momentum of the arc discharge in the deflection direction, that is, the welding line direction. The component force in the welding line direction of this momentum acts strongly on the molten metal melted by the welding arc, presses the molten metal in the welding line direction, and continues the molten metal in the adjacent joints with two gaps. Welding can be performed.

  In addition, by deflecting the radial shape of the welding arc, the radial surface shape projected on the welded portion can be formed in an egg shape that is long in the weld line direction and short in the direction perpendicular to the weld line. With this, heat input or preheating in a long region can be achieved, and a good weld with sufficiently deep penetration can be obtained.Besides the short width in the direction perpendicular to the weld line, it is possible to limit the heat input or preheating more than necessary, and Reduction can be achieved.

[Means of claim 2]
In the TIG welding method employing the means of claim 2, the magnetic field is characterized in that the magnetic field lines of the magnetic field pass substantially orthogonal to the arc current.

  Thereby, a large electromagnetic force generated by the electromagnetic interaction between the magnetic field and the arc current can be obtained, and the radiation shape of the welding arc can be sufficiently deflected.

[Means of claim 3]
In the TIG welding method employing the means of claim 3, the magnetic field passes through the magnetic field lines of the magnetic field substantially perpendicularly to the weld line direction of the two bonded portions of the bonded object.

  Thereby, a welding arc is deflected and the radiation surface shape of the welding arc projected on a to-be-joined part becomes an egg shape. The long axis direction of the egg shape can be made to coincide with the weld line direction, so that a long region of heat input or preheating can be achieved in the weld line direction, and a good weld with sufficiently deep penetration can be obtained. Moreover, since the acting force accompanying the change in the direction of momentum of the welding arc to be deflected can act in the weld line direction, the molten metal can be effectively continuously joined to the gap in the weld line direction.

[Means of claim 4]
In the TIG welding method employing the means of claim 4, the magnetic field is applied in such a manner that the direction connecting the two magnetic poles of the permanent magnet using the permanent magnet and the central axis of the electrode and the bonded portion are substantially orthogonal. It is characterized by.

  Thereby, a large electromagnetic force generated by the electromagnetic interaction between the magnetic field and the arc current can be obtained, and the radiation shape of the welding arc can always be greatly deflected. Further, by greatly deflecting, the welding line direction component force of the momentum of the welding arc can be increased.

[Means of claim 5]
The TIG welding method employing the means of claim 5 is characterized in that the object to be joined is a current conductor constituting a stator of a rotating electrical machine.

  As a result, welding of the small and precise current conductors that make up the stator of a rotating electrical machine can be carried out easily, satisfactorily and under the influence of low heat, which makes it possible to reduce costs and improve reliability. Become.

[Means of claim 6]
In the TIG welding apparatus employing the means of claim 6, the object to be joined includes a part to be joined that is melted and joined to one end in the longitudinal direction, and the two parts to be joined are arranged with a gap between them. Is a conductor terminal in which the direction of the welding line is the direction of the welding line, and an arc discharge is generated between the work piece and the electrode of the welding torch to generate a welding arc. A permanent magnet that generates a constant magnetic field substantially perpendicular to the magnetic field is provided, and the electromagnetic force generated by the electromagnetic interaction between the magnetic field generated by the permanent magnet and the arc current is applied to the welding arc, and the radial shape of the welding arc is joined. The welding is performed in such a manner that two parts to be joined are continuously joined by being deflected in the direction of the weld line of the part.

  Thereby, by using this TIG welding apparatus, the same effect as described in the means of claim 1 can be obtained. In addition, both magnetic poles are provided at both ends, and only a single permanent magnet with a rectangular cross section and a high magnetic flux density is arranged at a position aligned with the welding arc, so that a constant magnetic field is applied in a compact and powerful manner. Therefore, it is easy to perform accurate and good welding even to an object to be joined such as a small and precise conductor terminal such as a rotating electrical machine for automobiles. In addition, the device has a simple structure, and the cost is reduced.

[Means of Claim 7]
In the TIG welding apparatus employing the means of claim 7, the permanent magnet is a columnar single magnet or a horseshoe-shaped magnet having both magnetic poles at both ends and having a rectangular cross section, and is arranged in parallel or sandwiched with the welding arc. It is characterized by being arranged.

  This makes it possible to apply a constant magnetic field between the electrode and the object to be joined with a compact structure, and it is easy to weld accurately and quickly even to the object to be joined such as a small and precise conductor terminal. Become. In addition, the device has a simple structure, and the cost can be suppressed.

[Means of Claim 8]
The TIG welding apparatus adopting the means of claim 8 is characterized in that the permanent magnet is a rare earth magnet having a high magnetic flux density. As a result, a constant magnetic field can be applied more compactly and strongly, and it becomes easy to weld accurately and quickly even to an object to be joined such as a small and precise conductor terminal.

In the TIG welding apparatus, the best mode of the present invention is to form a radial shape of a welding arc generated between an electrode of a welding torch to which a negative electrode of a TIG welding machine is connected and a workpiece to be connected to a positive electrode. Deflection is performed by the electromagnetic force (Lorentz force) of a constant magnetic field generated by a permanent magnet arranged at a position aligned with the welding arc, and a desired egg-shaped radiation surface shape is obtained in the weld line direction of the welded portion. Increases heat input, causes the momentum of the deflected welding arc to act on the resulting molten metal in the direction of the weld line, generates an action force that presses in the direction of the weld line, and has two gaps adjacent to each other The molten metal of the part is joined continuously to each other.
The best mode of the present invention will be described together with Example 1 shown in the drawings.

[Configuration of Example 1]
FIG. 1 is a schematic view of a TIG welding apparatus provided with a permanent magnet for applying a constant magnetic field between an electrode of the present invention and a workpiece.
As shown in FIG. 1, the TIG welding apparatus 1 generates an arc discharge between an electrode 4 of a welding torch 3 to which a negative electrode of a TIG welder 2 is connected and a positive electrode and is connected to a workpiece 5. The electrode 6 is disposed. Although the center axis of the electrode 4 of the welding torch 3 and the center of the bonded portion 10 to be described later of the workpiece 5 are substantially coincident, preferably the central axis of the electrode 4 is slightly set in the anti-welding line direction of the bonded portion 10. The workpiece 5 is offset and pressed by the electrode 6 to be fixed. Thereby, the deflection | deviation margin of the welding arc 8 mentioned later is ensured, and the electrical continuity is also ensured. At the same time, the two conductor terminals 11 which are the objects to be bonded 5 are brought into close contact with each other to reduce the initial gap.

  Further, along with the welding arc 8 generated between the electrode 4 and the workpiece 5, the direction in which the permanent magnet 7 connects both magnetic poles at a position away from the central axis of the electrode 4 by a predetermined distance is the center line of the electrode 4. Arranged so as to be orthogonal to each other, the magnetic field lines of the magnetic field generated by the permanent magnet 7 pass perpendicularly to the center line of the electrode 4. In addition, in the TIG welding apparatus 1, an inert gas (not shown) is ejected from between the welding torch 3 and the electrode 4 to cover the surface of the welding arc 8 and prevent the weld 9 from being oxidized.

  As shown in FIG. 1, the permanent magnet 7 is a columnar single magnet having a rectangular cross-section, and the long side of the cross-sectional shape is equal to or greater than the conical radial tip widening width of the welding arc 8. The short side of the cross-sectional shape is substantially the same as the arc length of the welding arc 8, that is, the length between the electrode 4 and the bonded portion 10. The magnetic poles of the permanent magnet 7 are provided on both end faces of the columnar shape, the direction connecting the two magnetic poles and the arc center axis are orthogonal to each other, and the N poles are arranged opposite to each other, and the magnetic field lines are substantially the same as the welding arc 8. It passes through at right angles. It is important to pass a large amount of magnetic field lines through the welding arc 8 in order to obtain a desired effect. For this reason, the permanent magnet 7 is preferably a rare earth magnet having a high magnetic flux density. Thereby, a compact and powerful constant magnetic field can be obtained.

  The rectangular cross-sectional shape of the single magnet is substantially equal to the projected shape of the cross section of the central axis of the welding arc 8 because the magnetic field lines of the magnetic field orthogonal to only the welding arc 8 are allowed to pass. However, this magnetic field may leak and pass through, but it does not actively pass the magnetic field lines of the magnetic field through the molten metal 9. In addition, FIG. 1 shows an example in which the single permanent magnet 7 is arranged on the back side (back) of the paper surface, but the present invention is not limited to this, and it may be arranged on the front side (front side) of the paper surface. The S pole is opposed to the welding arc 8.

  Moreover, in a present Example, there exists a special characteristic in the shape of the to-be-joined object 5 which is a welding object. A workpiece 5 is a segment conductor part of a stator coil that serves as a stator of a rotating electrical machine such as an automotive alternator (alternator), and the conductor terminal 11 is composed of a rectangular conductor wire with an insulating coating. Then, one end of the segment is provided with a portion to be joined 10 that is chamfered so that it can be easily inserted and assembled by removing the insulating film. As shown in FIG. 1, the two chamfered conductor terminals 11 are combined adjacently, but the conductor terminals 11 are rarely in close contact with each other due to bending or distortion of the flat wire itself, and even when combined, there is a slight gap. May remain. Therefore, a gap left without being closely attached to the bonded portion 10 of the conductor terminal 11 and a gap due to chamfering are added, and a gap that cannot be ignored is generated between the bonded portions at one end, which makes welding difficult. Here, the special feature of the shape of the workpiece 5 is that the bonded portion 10 which is one end portion of the two conductor terminals 11 has a relatively large gap in the weld line direction of the bonded portion 10. Adjacent, and the gaps are not necessarily constant and have variations.

  The TIG welding method is a method in which the workpiece 5 is melted and joined by the welding arc 8. The welding arc 8 is an arc discharge that flows between the electrode 4 and the bonded portion 10 that is electrically connected to the electrode 6, and is a flow of charged particles in a high-temperature plasma state. The arc discharge basically occurs within the shortest distance between the electrode 4 and the bonded portion 10 and easily occurs on the central axis of the electrode 4, but has a conical radial shape that spreads in the direction in which the arc discharge extends. The arc discharge itself is a flow of charged particles in a plasma state. That is, when a current flows, a magnetic field is generated around the arc discharge by the current, that is, the arc current. This magnetic field is likely to change under the influence of the structure, shape, material, etc. of the object 5 to be joined, and the magnetic flux density around the arc discharge is assumed to be non-uniform, and irregularly drawn suddenly toward the higher magnetic flux density. May cause a magnetic blowing phenomenon that causes various fluctuations. If the radiation shape of the welding arc 8 fluctuates due to this magnetic blowing phenomenon, the heat input to the welded portion is remarkably reduced, and good welding may not be obtained.

  In the present embodiment, there is a possibility that the magnetism may be caused by a relatively large gap adjacent to each other in the weld line direction of the joined portion 10 of the two conductor terminals 11 and the gap is not necessarily constant and varies. The welding arc 8 that fluctuates including the blowing phenomenon is forcibly fixed and stabilized by effective means, and the kinetic energy of the welding arc 8 is effectively used to achieve a good joining method. In other words, as in the prior art, a magnetic field is applied to the current flowing through the molten metal 9, and Lorentz force generated by the electromagnetic interaction between the magnetic field and the current is applied to the molten metal 9 to obtain a continuous joint in the weld line direction. Further, without inclining the center axis of the electrode 4 of the welding torch 3 and the joined portion 10, the radial shape of the welding arc 8 is positively deflected, and the momentum in the welding line direction as the deflection direction is greatly earned, In this welding method, the acting force generated by the change in the direction of the momentum is pressed against the molten metal 9 to join the molten metal 9 continuously.

  As shown in FIG. 1, the radiation shape of the welding arc 8 generated between the electrode 4 of the welding torch 3 to which the negative electrode of the TIG welding machine 2 is connected and the workpiece 5 to which the positive electrode is connected is expressed as a welding arc. A constant magnetic field generated by a permanent magnet 7 arranged at a position aligned with 8 is applied, and a Lorentz force generated by an electromagnetic interaction between the magnetic field and an arc current is constantly applied to the welding arc 8, thereby deflecting the welding arc 8. Fixing, that is, forming a curved welding arc 8 to obtain a desired egg-shaped radiation surface shape in the weld line direction of the joined portion 10, increasing the heat input in the weld line direction, and resulting metal melt 9, the momentum of the deflected welding arc 8 is applied in the direction of the welding line to generate an action force that is pressed in the direction of the welding line, and the molten metal 9 of the two joints 10 are continuously joined to each other. Is the method. By this method, the molten metal 9 is moved more stably by the acting force of the welding arc 8 deflected more stably than the conventional welding method in which the molten metal 9 is continuously joined by applying the Lorentz force to the molten metal 9. Can be joined continuously.

[Effect of Example 1]
The effect of the present embodiment will be described. According to the TIG welding method, the welding arc 8 deflected by the Lorentz force generated by the electromagnetic interaction between the magnetic field and the arc current increases the component force in the welding line direction of the momentum of the arc discharge in the deflection direction, that is, the welding line direction. generate. The component force of the momentum in the welding line direction acts strongly on the molten metal 9 melted by the welding arc 8, presses the molten metal 9 in the welding line direction, and the metal of the adjacent joint 10 having two gaps. It is possible to perform welding in which the molten metal 9 is continuously joined together.

  Further, by deflecting the radiation shape of the welding arc 8, the radiation surface shape projected on the bonded portion 10 can be formed in an egg shape that is long in the weld line direction and short in the direction perpendicular to the weld line. In the linear direction, heat input or preheating in a long region can be achieved, and a good weld with sufficiently deep penetration can be obtained.In addition, the width in the direction perpendicular to the weld line is short, so that excessive heat input or preheating can be limited. The impact can be reduced.

  In addition, since both magnetic poles are provided at both ends, and a single permanent magnet 7 having a rectangular cross section with a high magnetic flux density is arranged at a position aligned with the welding arc 8, a constant magnetic field is compact and powerful. Therefore, it is easy to perform accurate and good welding on the object 5 such as a small and precise conductor terminal 11 such as a rotating electrical machine for automobiles. In addition, the device has a simple structure, and the cost is reduced.

[Configuration of Example 2]
A second embodiment of the present invention is shown in FIG. FIG. 2 shows a schematic view of a TIG welding apparatus including a permanent magnet that applies a constant magnetic field between an electrode and a workpiece.
Components that are substantially the same as those in the first embodiment are denoted by the same reference numerals, and detailed description thereof is omitted.

  In the TIG welding apparatus 1 of the first embodiment, the permanent magnet 7 is a columnar magnet having a rectangular cross section, and the long side of the cross sectional shape is equal to or larger than the conical radial tip end width of the welding arc 8. The short side of the cross-sectional shape is substantially the same as the arc length of the welding arc 8, that is, the length between the electrode 4 and the bonded portion 10, and both magnetic poles of the permanent magnet 7 are provided on both end faces of the columnar shape. A single magnet in which the direction connecting the two magnetic poles and the arc central axis are orthogonal to each other, and the N poles are arranged opposite to each other so that the magnetic field lines of the magnetic field pass substantially orthogonally to the welding arc 8. is there. However, the present invention is not limited to this. In the present embodiment, a horseshoe-shaped or channel-shaped magnet having a rectangular cross section, both magnetic poles are provided to face both end surfaces, and the welding arc 8 is sandwiched between the magnetic poles. And the magnetic field lines generated between the two magnetic poles are arranged so as to be orthogonal to the arc current.

  The difference from the first embodiment is that the shape of the permanent magnet 7 is a columnar shape or a horseshoe shape. The only difference is how the magnetic field generated between the two magnetic poles is applied, and the magnetic field lines pass perpendicular to the arc current. What you do does not change, and other configurations do not change.

[Effect of Example 2]
The TIG welding apparatus 1 in the present embodiment is mainly the difference in the position and shape of the magnetic poles of the permanent magnet 7 that generates a magnetic field, and other configurations are not changed, and the same operations and effects as in the first embodiment are obtained. It is done. In particular, it is easier to apply a high magnetic field when a welding arc 8 is sandwiched between both magnetic poles and a magnetic field generated between both magnetic poles is applied as in this embodiment, so that more reliable deflection and fixation can be achieved. If the same deflection and fixation can be realized, the TIG welding apparatus tends to be more compact.

FIG. 1 shows a schematic view of a TIG welding apparatus provided with a permanent magnet that applies a constant magnetic field between an electrode and a workpiece (Example 1). These show the schematic of the TIG welding apparatus which provided the permanent magnet which adds a fixed magnetic field between an electrode and a to-be-joined object (Example 2). Shows a schematic diagram of a TIG welding apparatus in which an electrode and an object to be joined are arranged to face each other (conventional example).

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 TIG welding apparatus 2 TIG welding machine 3 Welding torch 4, 6 Electrode 5 To-be-joined object 7 Permanent magnet 8 Welding arc 9 Metal molten metal (welding part)
10 Bonded part 11 Conductor terminal

Claims (8)

In the TIG welding method in which the workpieces are melted and joined by a welding arc,
The article to be joined includes a joined part that is melted and joined to one end in the longitudinal direction,
The two bonded parts are arranged with a gap;
It is a conductor terminal that makes the direction arranged with the gap the welding line direction,
An arc discharge is generated between the workpiece and the electrode of the welding torch to generate a welding arc,
Applying a constant magnetic field around the welding arc;
Electromagnetic force generated by electromagnetic interaction between the magnetic field and the arc current flowing in the welding arc is applied to the welding arc,
By deflecting the radial shape of the welding arc in the weld line direction of the joined portion,
A TIG welding method, wherein welding is performed to continuously join the two parts to be joined. In the TIG welding method according to claim 1,
The TIG welding method, wherein the magnetic field passes through the magnetic field lines of the magnetic field substantially orthogonal to the arc current. In the TIG welding method according to claim 1 or 2,
The TIG welding method, wherein the magnetic field lines of the magnetic field pass substantially perpendicular to the weld line direction of the two bonded portions of the bonded object. In the TIG welding method according to any one of claims 1 to 3,
The TIG welding method, wherein the magnetic field is applied in such a manner that a direction connecting both magnetic poles of the permanent magnet using a permanent magnet and a central axis of the electrode and the bonded portion are substantially orthogonal to each other. In the TIG welding method according to any one of claims 1 to 4,
The TIG welding method, wherein the object to be joined is a current conductor constituting a stator of a rotating electric machine. In a TIG welding apparatus that melts and joins workpieces by welding arc,
The article to be joined includes a joined part that is melted and joined to one end in the longitudinal direction,
The two bonded parts are arranged with a gap;
It is a conductor terminal that makes the direction arranged with the gap the welding line direction,
An arc discharge is generated between the workpiece and the electrode of the welding torch to generate a welding arc,
A permanent magnet that generates a constant magnetic field substantially orthogonal to the arc current is provided at a position aligned with the welding arc,
Electromagnetic force generated by electromagnetic interaction between the magnetic field generated by the permanent magnet and the arc current is applied to the welding arc,
By deflecting the radial shape of the welding arc in the weld line direction of the joined portion,
A TIG welding apparatus configured to perform welding for continuously joining the two joined parts. In the TIG welding apparatus according to claim 6,
The permanent magnet is a columnar single magnet or a horseshoe-shaped magnet having both magnetic poles at both ends and having a rectangular cross section, and is arranged in parallel with or sandwiching the welding arc. Welding equipment. In the TIG welding apparatus according to claim 6 or 7,
The TIG welding apparatus, wherein the permanent magnet is a rare earth magnet having a high magnetic flux density.

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