JP2751744B2 - Welding current control method for multi-electrode high-speed rotating arc - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a multiple electrode high-speed rotating arc welding method in which two consumable electrode wires are used and two arcs are simultaneously generated and synchronously rotated for welding. The present invention relates to a method for controlling a welding current of an electrode high-speed rotating arc.

[0002]

2. Description of the Related Art An arc welding method for welding by an arc generated between a consumable electrode wire (hereinafter, referred to as a welding wire) and a member to be welded. As shown in FIG. When a large current is applied to the wire 1, the arc shape P concentrates on one portion of the molten pool WP, so that the bead shape of the weld bead WB is poor and there is a problem in welding quality. 1
0 is an arc and M is a member to be welded.

[0003] Therefore, a high-speed rotating arc welding method has been proposed in which welding is performed while rotating an arc generated between a welding wire and a member to be welded in a circular motion (Japanese Patent Publication No. 63-63).
No. 39346). As a method for realizing this rotating arc, for example, there is a method for rotating an electrode nozzle through which a welding wire passes as disclosed in Japanese Patent Application Laid-Open No. 62-248571. FIG. 9 shows an outline of a welding torch according to this method.

That is, in this structure, the intermediate portion of the electrode nozzle 2 through which the welding wire passes is rotatably supported by the self-aligning bearing 7 at a position eccentric by a predetermined distance from the center of the rotating gear 3. , The upper portion of the electrode nozzle 2 is supported as a fulcrum 4 (the fulcrum 4 is formed by a self-aligning bearing (not shown)), and the gear 3 is rotated by a rotary motor 8 and a gear mechanism 9 in a direction indicated by an arrow 6. , The arc 10 generated at the tip of the welding wire 1 projecting from the tip of the electrode nozzle 2
Can make a circular motion.

According to such a rotary arc welding method, the bead shape and the penetration shape can be flattened by the dispersion of the arc force and the arc heat, and the bead shape is improved. The welding speed of the welding wire increases due to the centrifugal force of rotation,
Higher efficiency than when the arc is not rotated. In fillet welding and welding with a groove, an arc sensor-type welding line tracing control using waveforms of a welding current and an arc voltage can be performed. There are features such as.

[0006]

However, in the conventional rotary arc welding method, there is only one welding wire.
When the welding current is increased, the heat input increases, and in the case of single-sided butt welding, there is a problem that a pear crack is generated.

Therefore, it is conceivable to use a plurality of welding wires. In this case, however, there is a possibility that magnetic blowing of the arc may occur, and the arc becomes unstable and the amount of spatter generated increases. A problem arose.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and reduces the occurrence of magnetic blowing while maintaining the advantages of the high-speed rotary arc welding method, thereby achieving high-speed and high-efficiency welding with little spatter. It is an object of the present invention to provide a current control method for a multi-electrode high-speed rotating arc that enables the following.

[0009]

According to a first aspect of the present invention, there is provided a method for controlling a welding current of a multi-electrode high-speed rotating arc, in which two preceding and following consumable electrode wires arranged in series in a welding progress direction are made identical. In the multi-electrode high-speed rotary arc welding method of performing welding while rotating synchronously in the rotation direction and the rotation speed of the consumable electrode, the number of pulses of the pulse welding current per rotation of each consumable electrode is set to the same number, and welding is performed on these consumable electrode wires. The phases of the currents are reversed, and the average value of the welding current of the preceding consumable electrode wire is set to be larger than the average value of the welding current of the subsequent consumable electrode wire.

According to a second aspect of the present invention, there is provided a method for controlling a welding current of a multi-electrode high-speed rotating arc, in which two leading and trailing consumable electrode wires arranged in series in the welding progress direction have the same rotational direction and rotational speed. In the multi-electrode high-speed rotating arc welding method in which welding is performed while rotating synchronously, the phases of the welding current flowing through the two consumable electrode wires of the preceding and succeeding electrodes arranged in series in the welding progress direction are such that the peak values alternate. The average value of the welding current of the preceding consumable electrode wire is set to be larger than the average value of the welding current of the subsequent consumable electrode wire.

According to a third aspect of the present invention, there is provided a welding current control method for a multi-electrode high-speed rotating arc, wherein two consumable electrode wires, a leading electrode and a trailing electrode, which are arranged in series in a welding progress direction, have the same rotational direction and rotational speed. In the multi-electrode high-speed rotating arc welding method in which welding is performed while rotating synchronously, the peak value of the phase of the welding current flowing through the two consumable electrode wires of the preceding and succeeding electrodes arranged in series in the welding direction is set to 1/2 ⁿ (N
= 1 or 2) The average value of the welding current of the preceding consumable electrode wire is set to be larger than the average value of the welding current of the consumable electrode wire of the succeeding electrode so as to alternate every cycle.

[0012]

According to the present invention, when the two consumable electrode wires of the preceding and succeeding electrodes arranged in series in the welding progress direction are welded while being synchronously rotated in the same rotation direction and rotational speed, each of the consumable electrode wires is used. The number of pulses of the pulse welding current per one rotation is the same, the phases of the welding currents flowing through these consumable electrode wires are reversed, and the average value of the welding currents of the preceding consumable electrode wires is used for the following consumable electrode wires. Since the welding current is set to be larger than the average value, the product of the welding current flowing through the two arcs, which is proportional to the electromagnetic attraction force that causes the magnetic blowing, is suppressed to be smaller than when the phases are synchronized. Therefore, the amount of spatters generated by magnetic blowing is reduced, and a good welding bead shape can be obtained because the welding current on the preceding consumable electrode wire side where the arc is stabilized is large.

Further, when welding is performed while rotating the two consumable electrode wires of the preceding and succeeding electrodes arranged in series in the welding traveling direction while synchronously rotating in the same rotation direction and rotational speed, they are arranged in series in the welding traveling direction. The phases of the welding current flowing through the two preceding consumable electrode wires are alternately set to peak values, and the average value of the welding current of the preceding consumable electrode wire is calculated as the welding current of the following consumable electrode wire. Since the value is set to be larger than the average value, the amount of spatter generated by magnetic blowing is reduced, and a good welding bead shape can be obtained because the welding current on the preceding consumable electrode wire side where the arc is stabilized is large.

Further, when welding is performed while the two consumable electrode wires of the preceding and succeeding electrodes arranged in series in the welding progress direction are synchronously rotated in the same rotation direction and rotational speed, they are arranged in series in the welding progress direction. The phase of the welding current flowing through each of the two consumable electrode wires of the preceding and following lines has a peak value of 1
/ 2 ⁿ (n = 1 or 2) alternately every cycle,
Since the average value of the welding current of the preceding consumable electrode wire was set to be larger than the average value of the welding current of the following consumable electrode wire, the welding current alternately flows through the preceding and following consumable electrode wires. The welding current is almost the same as when only one consumable electrode wire is applied, and the occurrence of magnetic blowing is greatly reduced. The shape is obtained.

[0015]

FIG. 1 is a sectional front view showing a twin-wire rotary arc torch used in the method of the present invention, FIG. 2 is an explanatory view showing a welding state using two welding wires, and FIG. FIG. 4 is an explanatory diagram showing the rotational locus of two welding wires, FIG. 4 is an explanatory diagram showing the rotational position of the welding wire in the welding traveling direction, and FIG. 5 is a diagram showing the rotational positions of the two welding wires and the waveform of the welding current flowing through them. FIG. 6 is a waveform diagram showing a relationship.

In the twin-wire rotary arc torch shown in FIG. 1, when the gear 3 and the rotating body 15 are rotated by the rotating motor 8 and the driving gear 9b, the upper end of the electrode nozzle 2 becomes a fulcrum 4
As an insulated bush 12 and a self-aligning bearing 13, the intermediate portion circularly moves around the rotation center axis 5 by the eccentric ring 19 with a predetermined eccentricity e without rotating. In other words, the tip of the electrode nozzle 2 rotates with the upper end as the fulcrum 4. Since the two welding wires 1 are guided by the conduit tube 21 at positions eccentric from the center of the electrode nozzle 2 that makes such a rotational movement, the tip of the welding wire 1 protruding from the energizing tip 22 is As shown in FIG. 4, a circular motion is made without rotating around the rotation center axis 5. Therefore, the arcs simultaneously generated from the tips of the respective welding wires 1 rotate synchronously in the same rotational direction and rotational speed. When the welding torch is advanced on the welding line while being rotated as described above, the rotating arc draws a loop-like locus. That is, as shown in FIGS. 2 and 3, this welding torch can synchronously rotate two welding wires 1 serving as a leading electrode L and a trailing electrode T in the same rotation direction and rotation speed.
The electrode nozzle 2 has a mechanism for insulating the two welding wires 1 from each other.

Next, a case where the method of the present invention is carried out using the twin-wire rotary arc torch shown in FIG. 1 will be described. Each welding wire 1 of the twin-wire rotary arc torch is rotated under the following rotation conditions to perform arc welding. Rotation speed: N = 30 to 500 Hz Rotation diameter: D = 1 to 6 mm Distance between electrodes: d = 5 to 100 mm

At this time, the two welding wires 1 are synchronously rotating in the same rotation direction and rotation speed as described above.
Also, welding is performed by passing a pulsed welding current as shown in FIG. 5 to the two welding wires 1 and 1 serving as the leading electrode L and the trailing electrode T.

That is, the peak current I _P is 8
00A, the base current I _B is 200A, the average current I _AV 5
00A, t _P (peak time): t _B (base time) =
At 1: 1, the welding current of one pulse per rotation of the welding wire 1 is adjusted so that the peak current I _P and the rotation rear Cr side are within the 180 ° angle range of 270 ° to 90 ° on the rotation front Cf side shown in FIG. a base current I _B in the angular range of 180 ° of 90 ° to 270 ° shed so as to be located. Peak current I _P to the trailing electrode T is 500A, the base current I _B is 100A, the average current I _AV is 300A, t _P (peak time): t _B (base time) = 1: 1, the welding wire 1 The welding current of one pulse per rotation was changed from 270 ° to 90 ° on the rotation front Cf side shown in FIG.
Base current I _B , rotation back C
peak current I _P to the angular range of 180 ° of the r side of 90 ° to 270 ° shed to be located.

[0020] Thus, shifted as two electrodes L of the preceding and the following, which are arranged in series, the peak current I _P the phase of the pulsed welding current to flow respectively to T comes alternately in welding direction WD the Rukoto, because it is suppressed as compared with the case the product is the peak current I _P of the welding current flowing through the two arcs that affect electromagnetic attraction force that could cause such a blow magnetism are synchronized with each other, the magnetic blow Is reduced.

The average value I _AV of the welding current of the leading electrode L
There because they are larger than the average value I _AV of the welding current of the trailing electrode T, good bead shape is obtained.

Next, welding is performed by applying a pulse-like welding current as shown in FIG. 6 to the two welding wires 1 and 1 serving as the leading electrode L and the trailing electrode T. That is, the leading electrode L peak current I _P to the 1000A, base current is I _B 333A,
When the average current I _AV is 500 A, t _P : t _B = 1: 3, and the welding current of one pulse per one time of the welding wire 1 is changed to the rotation forward C
peak angle range of 90 ° the f side of 315 ° to 45 ° current I _P, the angle range other than the angle range of the peak current I _P is the base current I _B flows so as to be located. Peak current I _P to the trailing electrode T is 600A, the base current I _B is 200A,
At an average current of 300 A, t _P : t _B = 1: 3, the welding current of one pulse per one time of the welding wire 1 is applied to the peak current I _P and the peak current in an angle range of 135 ° to 245 ° on the Cr side after rotation. I _P angular range than the angular range to the base current I _B
Pour so that is located. Incidentally, the welding current ratio of I _AV of I _AV and trailing electrode T of the leading electrode L is 0.6 to 0.7.

As described above, the phase of the pulse-like welding current flowing to the two preceding and succeeding electrodes L and T arranged in series in the welding advancing direction WD is determined by changing the phase of the peak current I _P every half cycle. Arc 1 by shifting alternately
At the time of rotation, the welding current flows alternately to the leading and trailing electrodes L and T, which is the same state as flowing the welding current to one welding wire, and the occurrence of magnetic blowing is greatly reduced. Becomes

In the embodiment shown in FIG.
In the example shown in FIG. 7A, one pulse of the welding current flows per one rotation of the welding wire, and as shown in FIG. The peak current I _{P of the} welding current flowing to the electrode T is shifted alternately, or the welding current of 4 pulses per rotation of each welding wire 1 is applied as shown in FIG.
The peak current I _P of the welding current to be supplied to the trailing electrode T is or as shifting to come alternately and, of course having the same operations and effects as described above.

In each of the above-described embodiments, the twin-wire rotary arc torch shown in FIG. 1 is used to synchronously rotate the leading electrode L and the trailing electrode T in the same rotation direction and rotation speed. Is not limited to this,
It goes without saying that the method of the present invention can be carried out as long as two electrodes arranged adjacent to each other are synchronously rotated in the same rotational direction and rotational speed.

Further, in the above-described embodiment, the case where the number of rotating electrodes is two is compared. However, even if two or more electrodes are used, if the phases of the welding currents flowing through these electrodes are shifted from each other, the method of the present invention is used. Of course is applied.

[0027]

As described above, the present invention is applicable to the case where welding is performed while synchronously rotating two preceding and following consumable electrode wires arranged in series in the welding traveling direction in the same rotational direction and rotational speed. The number of pulses of the pulse welding current per rotation of each consumable electrode is set to the same number, and the phases of the welding currents flowing through these consumable electrode wires are reversed.
Since the average value of the welding current of the preceding consumable electrode wire is set to be larger than the average value of the welding current of the subsequent consumable electrode wire, the current flows through two arcs proportional to the electromagnetic attraction force that causes magnetic blowing. The product of the welding current is reduced compared to the case where the phases are synchronized, so that the amount of spatter generated by magnetic blowing is reduced. By obtaining a weld bead shape, there is an effect that highly efficient and stable welding can be performed with a large current.

Further, when welding is performed while two consumable electrode wires, preceding and succeeding, arranged in series in the welding progress direction are synchronously rotated in the same rotation direction and rotational speed, they are arranged in series in the welding progress direction. The phases of the welding current flowing through the two preceding consumable electrode wires are alternately set to peak values, and the average value of the welding current of the preceding consumable electrode wire is calculated as the welding current of the following consumable electrode wire. Since the value is set to be larger than the average value, the amount of spatter generated by magnetic blowing is reduced, and an excellent welding bead shape can be obtained because the welding current on the preceding consumable electrode wire side where the arc is stabilized is large.

Further, when welding is performed while rotating the two consumable electrode wires of the preceding and succeeding electrodes arranged in series in the welding progress direction in the same rotation direction and the same rotation speed, they are arranged in series in the welding progress direction. The phase of the welding current flowing through each of the two consumable electrode wires of the preceding and following lines has a peak value of 1
/ 2 ⁿ (n = 1 or 2) alternately every cycle,
Since the average value of the welding current of the preceding consumable electrode wire was set to be larger than the average value of the welding current of the following consumable electrode wire, the welding current would flow alternately through the preceding and following consumable electrode wires. Good welding bead because the welding current flows through only one consumable electrode wire, and the occurrence of magnetic blowing is greatly reduced, and the welding current on the preceding consumable electrode wire side where the arc is stable is large. This has the effect that a shape can be obtained.

[Brief description of the drawings]

FIG. 1 is a sectional front view showing a twin-wire rotary arc torch used in the method of the present invention.

FIG. 2 is an explanatory diagram showing a welding state using two welding wires.

FIG. 3 is an explanatory diagram showing rotation trajectories of two welding wires located above a molten pool.

FIG. 4 is an explanatory diagram showing a rotation position of a welding wire in a welding traveling direction.

FIG. 5 is a waveform diagram showing a relationship between rotational positions of two welding wires and waveforms of a welding current flowing through them.

FIG. 6 is a waveform diagram showing another welding current waveform flowing through two welding wires.

FIG. 7 is an explanatory view showing a state in which a welding current of a plurality of pulses per rotation flows through two welding wires.

FIG. 8 is an explanatory view showing a welding state using a conventional single welding wire.

FIG. 9 is a perspective view showing an outline of a conventional welding torch.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 welding wire 2 electrode nozzle 3 gear 4 fulcrum 5 rotation center axis 8 rotation motor 9b drive gear

──────────────────────────────────────────────────続 き Continuation of front page (56) References JP-A-58-157575 (JP, A) JP-A-62-45473 (JP, A) JP-A-62-24865 (JP, A) JP-A 62-45865 24866 (JP, A) JP-A-1-178373 (JP, A) JP-A-63-313674 (JP, A) (58) Fields investigated (Int. Cl. ⁶ , DB name) B23K 9-9 / 127

Claims (3)

(57) [Claims] 1. A precedent arranged in series in a welding traveling direction.
In the multi-electrode high-speed rotating arc welding method in which the two subsequent consumable electrode wires are welded while rotating synchronously in the same rotational direction and rotational speed, the number of pulses of the pulse welding current per rotation of each consumable electrode is the same. and then, and then the mutually opposite phase of the welding current flowing in these consumable electrode wire, leading consumable electrode wire
The average value of the welding current of the
A welding current control method for a multi-electrode high-speed rotating arc, wherein the welding current is set to be larger than an average value of a flow . 2. A precedent arranged in series in a welding traveling direction.
Rotate the two consumable electrode wires in the same direction and direction.
Multi-electrode high-speed rotating
In over click welding process, the peak value of the phase of the welding current flowing respectively in two consumable electrode wires leading and trailing arranged in series welding direction is to come alternately previous consumable electrode wire of the welding current 2. The welding current control method for a multi-electrode high-speed rotating arc according to claim 1, wherein the average value of the welding current of the following consumable electrode wires is set to be larger than the average value of the following. 3. A method according to claim 1, further comprising the steps of:
Rotate the two consumable electrode wires in the same direction and direction.
Multi-electrode high-speed rotating
In the arc welding method, the phase of the welding current flowing through the two consumable electrode wires of the leading and trailing electrodes arranged in series in the welding progress direction is changed by a peak value every 1/2 ⁿ (n = 1 or 2) cycle. So that they come alternately
And the average value of the welding current of the preceding consumable electrode wire
Set the welding current of the consumable electrode wire larger than the average value.
2. The method for controlling a welding current of a multi-electrode high-speed rotating arc according to claim 1.