JPS60177965A - Hot wire tig welding device - Google Patents

Abstract

PURPOSE:To obtain a sound narrow gap hot wire TIG welded joint free from welding defect by swinging a wire heated by electricity from side to side in the narrow gap. CONSTITUTION:A wire 7 is plastic-deformed to the same shape as a gear 8 when it psses through the wire forming gear 8 and made to a bent wire 3. The wire 3 is led by a wire feeding guide 9 energized by a feeding chip 10, and fed to a molten pool near right under an electrode 2. When the wire 3 is plastic-deformed to chevron shape as shown in the figure, and sent to above-mentioned molten pool, the wire 3 is melted continuously in the molten pool. Consequently, the tip of the wire 3 moves from side to side in the molten pool of the narrow gap 5. Thus, the welding arc is deflected in the groove 5, and incomplete fusion on the side wall of the groove 5 can be prevented. The wire can also be swung from side to side in the groove by mechanical method instead of plastic deformation.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Application of the Invention] The present invention relates to a TIG welding device that passes a wire (hot wire TIG welding device), and particularly to a hot wire TIG welding device suitable for performing narrow gap welding.

[Background of the invention]

The conventional hot wire tee (1) welding method, in which wires are heated with electricity, is a clean, high-efficiency welding method that increases the amount of welding due to Joule heat generated by heating the wire with electricity. When this is done, the welding arc does not fully spread within the groove, which tends to cause welding defects such as poor fusion on the sidewalls of the groove.

Conventional hot wire TIG welding equipment is intended for normal wide-gap welding, and does not take narrow-gap welding into consideration.

[Purpose of the invention]

An object of the present invention is to compensate for the drawbacks of the prior art described above in narrow gap welding, and to obtain a sound narrow gap hot wire TIG welded joint free of welding defects.

[Summary of the invention]

In narrow gap TIG welding, the present invention applies plastic deformation to an electrically heated wire so that it swings from side to side within the gap, or mechanically swings the wire and uses the magnetic field generated by the wire's current flow to perform welding. This is a hollow 1-wire TIG welding device for preventing the occurrence of poor fusion of the groove sidewall by deflecting the arc left and right within the sandwich tip and obtaining a sound sandwich (2) tip hot wire TIG welding joint.

[Embodiments of the invention]

FIG. 1 shows an embodiment of the present invention. The part that feeds the wire 7 includes a wire forming gear 8 that gives plastic deformation to the wire 7;
It is comprised of a wire feeding guide 9 that guides the feeding direction of the bending wire 3 that has been plastically deformed, and a power feeding chip 10 that energizes the bending wire 3.

When the wire 7 passes through the wire forming gear 8, it is plastically deformed into the same shape as the tooth profile of the wire forming gear 8, and becomes the bent wire 3. The bending wire 3 is guided by a wire feeding guide 9, energized by a power feeding tip 10, and fed to the molten pool directly below and in the vicinity of the electrode 2. The bent wire 3 is shown in FIG. 1(a).
When the bending wire 3 is plastically deformed into a rectangular shape as shown in FIG. Move left and right in the pool. The relationship (3) between the welding arc 6 and the feeding position of the bending wire at that time is shown in FIG. FIG. 2(a) shows the occurrence of a weld hole 96 when narrow gap welding is performed by conventional hole 1 to wire tag welding. In the conventional method, the welding arc 6 does not spread sufficiently within the narrow groove 5, so the side walls of the groove are not melted. As a result, poor fusion is likely to occur, and the weld bead 1-4 becomes convex, causing a cut between the weld bead 4 and the side wall of the narrow groove 5, causing poor fusion. FIGS. 2(b) and 2(C) show the occurrence of welding tool 96 in the case of the present invention. When the direction of the current in the bending wire 3 is from the bending wire 3 to the base metal, and the direction of the current in the electrode 2 is from the base metal to the electrode 2, the welding arc 6 generated at the electrode 2 is induced by the current flowing through the bending wire 3. It receives a Lorentz force due to the magnetic field and is deflected in a direction opposite to the position of the bent wire 3. As a result, when the tip of the bending wire 3 is located on the left side of the narrow gap 5 shown in FIG. 2(b), the welding arc 6 is deflected to the right side of the narrow gap 5, melting the right side wall of the narrow gap. . Also, the bending wire 3 melts and the tip of the bending wire 3 changes from the position shown in Fig. 2(b) to the position shown in Fig. 2(C).
), the welding arc 6 is deflected to the left side of the narrow gap 5 (4). As a result, penetration of the side wall portion of the narrow gap 5 is improved, and the shape of the weld bead 4 becomes concave, so that a sound narrow gap welded joint without fusion defects can be obtained. Further, FIG. 3 shows the arc deflection situation when the direction of the current flowing through the bending wire 3 is from the base material to the direction of the bending wire. In this field, the welding arc 6 is attracted toward the bending wire 3 due to the induced magnetic field caused by the current flowing through the bending wire 3. As a result, when the tip of the bending wire 3 is located on the left side of the narrow groove 5, the welding arc 6 is deflected to the left and melts the side wall of the narrow groove 5.

In addition, when the bending wire 3 is melted and its tip is located on the right side of the narrow groove 5, the welding arc 6 is deflected to the right side, melting the right groove side wall, and producing a weld bead 4 with good weld penetration. It will be done. As the bending wire 6 is continuously melted, it swings left and right within the groove, and in accordance with the movement, the welding arc 6 is continuously deflected left and right. In addition, the welding arc 6 is connected to the bending wire 3.
By being pulled in this direction, the bending wire 3 is subjected to a preheating effect by the welding arc 6, increasing the welding speed.

(5) Figure 4 shows the magnetic flux density generated around the wire when a current that does not generate an arc is passed through the wire on a flat plate. Generally, welding arc has a surrounding magnetic flux density of 1
If there is a magnetic field of 0 to 20 Gauss or more, it will be deflected, and the distance between the tip of the TIG electrode and the tip of the wire is usually 5 to 1.0 m.
It is about m. As shown in Figure 4, by passing a current of about 60A through the wire, it is possible to
At the position m, a magnetic flux density of 1020 Gauss or more is obtained. Therefore, the welding arc can be deflected with a wire current of about 60A.

FIG. 5 shows the magnetic flux density generated around the wire in the groove when the wire current is 120 A. Figure 4 (
As is clear from the comparison between Figure 5 (on a flat plate) and Figure 5 (inside the groove), the magnetic flux density due to wire energization tends to increase within the groove, and the problem with this welding method is narrow groove (groove width). 1
In single-pass, single-layer welding (with a thickness of 5 mm or less), the magnetic flux density increases in particular, and it is thought that sufficient welding arc deflection can be achieved with low current wire energization.

(6) Figure 6 shows the relationship between wire current and welding arc deflection when the wire is energized on a flat plate. The welding arc deflection angle tends to increase as the wire current increases and the electrode current (welding current) decreases. This is because as the wire current increases, the strength of the magnetic field induced by the wire current increases, and as the electrode current (welding current) decreases, the welding arc force decreases. The higher the wire current, the more effective the welding arc deflection, but if the wire current is too high, the wire will arc. The current that generates an arc from the wire is related to the wire feed rate, but at a wire feed rate of about 3 m/mj n, the wire has a current of 150 to 200
When a current of A flows, an arc occurs. Therefore, the wire current should be below +50A. Further, in TIG welding, the welding current is usually 200 to 300A. From Figure 6, even when welding on a flat plate, the wire current is 6'
By flowing approximately OA, the welding arc is deflected by approximately 10°.

Also, as shown in Figure 5, it is easier to deflect when welding within a groove than when welding with a flat plate, so when hot wire TIG welding with a narrow (7) groove, a current of about 50 A is applied to the wire. It is thought that a sufficient effect can be obtained by flushing the water. From the above, in narrow gap hot wire TIG welding, by flowing an electrode current (welding current) of 200 to 300 A and a wire current of about 50 to 150 A, sufficient deflection of the welding arc occurs and a good narrow gap 1 pass 1 Can perform layer welding.

FIG. 7 shows an embodiment in which the welding arc is deflected by mechanically swinging the wire from side to side within the groove. The wire feeding portion includes a wire vibrating panel 11 and a wire feeding amount roller 8.
, a wire feeding guide 9, and a wire feeding tip 10. The wire 7 is mechanically vibrated left and right by a wire vibrating panel 11 and is fed by a wire feed roller 8 , passes through a wire feed guide 9 , and is fed into the molten pool immediately below the electrode 2 . The wire 7 is wire feeding roller 8
By being mechanically vibrated by the wire vibrating panel 1 before entering the wire, the wire becomes a bent wire 3 that vibrates from side to side. Immediately before the bending wire 3 is fed into the molten pool, a current is passed through the wire feeding tip (8) 10. The bending wire 3 is continuously melted within the melt pool, so that the tip of the bending wire 3 vibrates continuously from side to side within the groove. Since the bending wire 3 is energized from the wire power supply tip 10, an induced magnetic field is generated around the bending wire 3, so that the welding arc 6 is deflected left and right in accordance with the tip position of the bending wire 3, and the groove Melt the side wall. Note that the relationship between the deflection direction of the welding arc 6 and the position of the bending wire 3 is similar to the direction of the current flowing through the electrode and the direction of the current flowing through the bending wire, which have already been described.

The welding arc is synchronized with the movement of the wire by swinging the energized wire from side to side within the narrow gap using the method of plastic deformation of the wire or mechanical vibration as shown in FIGS. 1 and 7 of the embodiment. It vibrates from side to side within the narrow gap. As a result, when performing one-pass, one-layer welding in a narrow gap, it is possible to prevent poor fusion of the narrow gap side wall, which is the most worrying welding defect.
A good narrow gap hot wire TIG welded joint can be obtained.

[Brief explanation of the drawing]

(9) Figure 1 is a schematic diagram of the welding method using wire plastic deformation, Figures 2 and 3 are diagrams of welding arc generation, and Figures 4 and 5 are magnetic flux due to wire energization on the flat plate and within the groove. A diagram showing the density, Figure 6 is a diagram showing the relationship between wire current and welding arc deflection,
FIG. 7 shows a schematic diagram of a welding method using mechanical wire vibration. 1. Welding 1--chi, 2. Electrode, 3. Bend wire, 4
...welding bead, 5..narrow gap, 6..welding arc,
7... Wire, 8... Wire feeding roller, 9... Wire feeding guide, 10... Wire feeding tip, 11...
・Wai (10) Inn 1 diagram (e-) House 2 diagram (CIJ (g) (C) High school 3rd diagram also 1 diagram distance cL (mTn) Distance - atLcL (v+1 Scold 6 diagram wire electric cutting (8)

Claims (1)

[Claims]] A TIG welding device that energizes a wire, characterized in that the welding arc is deflected in synchronization with the wire position by giving plastic deformation to the wire and swinging the wire from side to side within the groove. Hola 1 - Wire TIG welding equipment. 2. The wire welding device according to claim 1, characterized in that the arc is deflected by mechanically swinging the wire from side to side within the groove.