JPH05253672A - Consumable electrode arc welding method and welding machine thereof - Google Patents

Abstract

PURPOSE:To prevent the position of an arc generated by a consumable electrode wire from varying irregularly by various factors such as impedance of base metals and other parts and to perform efficient and appropriate arc welding. CONSTITUTION:The consumable electrode arc welding method where a current is supplied to the consumable electrode wire 1a to generate the arc 8 and while the current in the opposite direction to the current carried to the consumable electrode wire 1a is carried to a filler wire 1b arranged in the rear of the consumable electrode 1a, the filler wire 1b is inserted into a molten pool 10 to perform welding is provided. The current is then supplied to the filler wire 1b from a separate welding power source 2b from a welding power source 2a to supply electric power to the consumable electrode wire 1a and constant current control to maintain constant a current value carried to the filler wire 1b is carried out.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a consumable electrode type arc welding method using a consumable electrode wire and a filler wire, and a welding machine used in the method.

[0002]

2. Description of the Related Art Conventionally, as an example of this kind of consumable electrode type arc welding method, a method disclosed in Japanese Patent Laid-Open No. 3-275280 has been developed and proposed. In this conventional arc welding method, as shown in FIG. 4, among two consumable electrode wires 1a and filler wires 1b arranged in parallel, the consumable electrode wire 1a as the preceding wire is used to bond the base metal 7 and the weld metal 9. The arc 8 is generated at the end of the filler wire 1b as a trailing wire and the tip of the filler wire 1b is inserted into the molten pool 10. Also, from the welding power source 2E to the consumable electrode wire 1
A part of the welding current flowing through the base material 7 via a is diverted to the filler wire 1b and merged with the welding power source 2E, and the consumable electrode wire and the filler wire 1b have opposite current directions. It is configured to be in the direction (arrows a and b).

According to such an arc welding method, the filler wire 1b can be melted by the heat of the molten pool 10. Therefore, the amount of electric power supplied to the consumable electrode wire 1a, that is, the heat input during welding can be greatly increased. Instead, the melting rate of the entire wire can be increased. Therefore, when the welding current is increased, there is an advantage that even with an aluminum alloy or the like, which is likely to cause puckering or welding distortion, it is possible to perform welding with high work efficiency without causing problems thereof. Also, if the directions of the currents flowing through the wires 1a and 1b (arrows a and b) are opposite, the wires 1a and 1b
Since the magnetic fields generated around each part of b generate repulsive forces with each other, the arc 8 is appropriately pushed forward (direction of arrow B),
Filler wire 1b even if both wires 1a, 1b are brought close to each other
Will not be melted and scattered by the arc 8. Therefore, the filler wire 1b is replaced with the consumable electrode wire 1a.
Can be provided in close proximity to it, and this also allows proper insertion into the weld pool 10.

[0004]

However, in the above-described arc welding method, a part of the welding current flowing through the base metal 7 is diverted to the filler wire 1b.
The magnitude of the current flowing through the filler wire 1b is not stable,
Even when a constant current was constantly supplied to the other consumable electrode wire 1a, it varied irregularly. That is, the magnitude of the current flowing through the filler wire 1b is determined by the welding power source 2E.
Is affected by impedances from the cathode terminal to the base material 7 and the filler wire 1b, but the difference in impedance is not always constant, and is irregular due to changes in the welding location and various external and internal factors. It fluctuates. Therefore, due to the change in the impedance, the value of the current flowing through the filler wire 1b was irregularly increased or decreased.

However, when the value of the current becomes unstable in this way, the filler wire 1b and the consumable electrode wire 1a are
Since the repulsive force of the magnetic field generated around each of the and changes irregularly, the position of the arc 8 also changes irregularly (causing shake) due to the influence of the magnetic field, and the arc 8 is optimal for welding. Can not be fixed to a certain place of.
As a result, conventionally, the swaying arc 8 improperly melts the filler wire 1b behind the arc 8, or the arc 8 is excessively pushed forward and the filler wire 1b is generated in the molten pool 10 generated by the arc 8. In some cases, it was impossible to insert the wire properly, and there were many problems such as a decrease in welding speed and a decrease in quality of weld finish.

The present invention has been proposed in view of the above point, and the position of the arc generated in the consumable electrode wire is irregularly changed by various factors such as impedance of the base material and other parts. The purpose of this is to prevent the occurrence of arcing and to perform efficient and appropriate arc welding.

[0007]

SUMMARY OF THE INVENTION The consumable electrode type arc welding method according to the present invention, which is proposed to achieve the above object, provides a consumable electrode wire with an electric current to generate an arc. Along with the filler wire arranged behind the consumable electrode wire, a consumable electrode type arc welding method of welding by inserting the filler wire into the molten pool while flowing a current in a direction opposite to the current flowing through the consumable electrode wire, A current is supplied to the filler wire from a welding power source different from a welding power source that supplies power to the consumable electrode wire, and constant current control is performed to make the current value flowing through the filler wire constant.

According to a second aspect of the present invention, there is provided a consumable electrode type arc welding method according to the first aspect of the present invention, wherein in the filler wire, an alternating signal component is superimposed on a direct current reference component. It is a method of supplying a control current having a different waveform.

A consumable electrode type arc welding machine according to the present invention as claimed in claim 3 for carrying out the method as claimed in claim 1 has a consumable electrode wire for generating an arc and the consumable electrode wire. A consumable electrode type arc welder comprising a filler wire arranged in parallel with an electrode wire, wherein both the consumable electrode wire and the filler wire are for supplying currents whose current directions are opposite to each other. Welding power sources are individually provided, and the welding power source for supplying current to the filler wire is configured to perform constant current control to make the current value flowing through the filler wire constant.

Further, the consumable electrode type arc welding machine according to the present invention as set forth in claim 4 proposed for carrying out the method as set forth in claim 2 has the structure described in claim 3 above. The welding power source for supplying current to the filler wire is configured to change the current supplied to the filler wire to a control current having a waveform in which an AC signal component is superimposed on a DC reference component.

[0011]

In the consumable electrode type arc welding method according to the present invention as set forth in claim 1, the filler wire is welded separately from the welding power source for supplying power to the consumable electrode wire. Since the current is supplied from the power supply and the current value is constant, the repulsive force of the magnetic field generated around each of the filler wire and consumable electrode wire due to changes in the impedance of the base material and other parts. Can be prevented from fluctuating irregularly. Therefore, the position of the arc can be fixed to a position most suitable for welding in relation to the position where the filler wire is arranged.

Further, in the consumable electrode type arc welding method according to the present invention as defined in claim 2, by supplying a control current having a desired waveform to the filler wire, the current value flowing through the filler wire is regularly changed. In addition, the repulsive force of the magnetic field generated around each of the filler wire and the consumable electrode wire can be regularly changed accordingly. Therefore, a so-called weaving operation or the like can be performed by regularly moving the arc by the repulsive force of the magnetic field. It should be noted that such arc position changes are performed regularly according to the current waveform, and the conventional irregular arc movement caused by changes in impedance is basically the purpose, operation function, and action. It is different. That is, the regular arc position change according to the present invention contributes to the improvement of the efficiency of the welding work such as the weaving operation, but the conventional irregular arc movement can never produce the action as the present invention. Is.

Furthermore, in the consumable electrode type arc welding machine according to the present invention as defined in claim 3 and claim 4, the consumable electrode power supply is provided separately for both the consumable electrode wire and the filler wire. Since a predetermined constant current or a control current having a predetermined waveform can be supplied to the electrode wire and the filler wire, respectively, the consumable electrode type arc welding method according to claim 1 or 2 can be appropriately implemented.

[0014]

【Example】

[Embodiment of apparatus (corresponding to claims 3 and 4)] First, an embodiment of the consumable electrode type arc welding machine according to the present invention will be described.
FIG. 1 is an explanatory diagram showing the schematic configuration thereof. The arc welding machine shown in the figure supplies a consumable electrode wire 1a for generating an arc, a filler wire 1b for inserting a tip portion into a molten pool, and a predetermined current individually to each of these wires 1a, 1b. It comprises welding power sources 2a and 2b for doing so and various devices described later.

Here, the consumable electrode wire 1a and the filler wire 1b are fed from the wire reels 3a and 3b to the feeding roller 4.
It is provided so that it can be sequentially drawn out toward the base material side by driving a and 4b, and each tip portion thereof projects downward from the tip opening portion of the gas nozzle 5. The gas nozzle 5
Is for discharging a desired shield gas such as argon gas or carbon dioxide. The tips of the wires 1a, 1b are arranged in parallel with each other at a narrow interval, but one consumable electrode wire 1a is on the front side with respect to the welding proceeding direction (arrow A direction) and the other filler. Wire 1b
Is set to be located behind it. The filler wire 1b may be tilted within an angle range of, for example, about 20 ° with respect to the consumable electrode wire 1a, other than being provided in parallel with the consumable electrode wire 1a.

Of the two welding power sources 2a and 2b, one welding power source 2a has its anode side connected to the tip 6a for the consumable electrode wire 1a via the wiring L1 and its cathode side via the wiring L2. The arc 8 can be generated between the consumable electrode wire 1a and the base material 7 and the deposited metal 9 by being connected to the material 7. The welding power source 2a performs constant current control so that the value of the current Ia flowing through the consumable electrode wire 1a becomes a constant current value preset by a setting switch or the like. This constant current control is performed, for example, by causing the welding power source 2a to perform a measured value of the current value or the voltage value of the current Ia and changing and controlling the voltage of the welding power source 2a according to the feedback value. As the welding power source 2a, a power source having a drooping characteristic may be used.

In contrast to the welding power source 2a, the other welding power source 2b has its cathode side connected to the tip 6b for the filler wire 1b via the wiring L3 and its anode side connected to the wiring L2 via the wiring L4. Has been done. However,
The wiring L2 is grounded, and the welding power source 2b can supply a current Ib to the filler wire 1b in a direction opposite to the current Ia flowing through the consumable electrode wire 1a. The welding power source 2b is configured to be able to supply to the filler wire 1b by selecting either one of two types of control currents having a waveform described later by operating a changeover switch or the like. That is, as the control currents of two types of waveforms, as a first example, a constant current type (corresponding to claim 3) in which the value of the current Ib flowing through the filler wire 1b is constant as shown in FIG. As an example of FIG.
A constant current type having a waveform obtained by superimposing an AC wave-shaped signal component on a constant reference current value N as shown in FIG.
Is applied to the welding power source 2b, and the welding power source 2b is configured to be capable of supplying both types of currents by switching them arbitrarily (however, FIGS. 2 and 3 show the absolute value of the currents ignoring the positive / negative of the potential). It was done). Even in the welding power source 2b, one of the weldings is performed so that the value of the current Ib actually flowing in the filler wire 1b has the waveform as described above without being influenced by the change in the impedance of the base material 7 or the like. Like the power supply 2a, it is provided with a feedback control means for the measured value of the current Ib.

[Example of method (corresponding to claims 1 and 2)]
Next, an example of a consumable electrode type arc welding method using the consumable electrode type arc welding machine shown in FIG. 1 will be described. First, the consumable electrode wire 1a is used as a leading wire, and the filler wire 1b is used as a trailing wire.
A predetermined direct current is supplied from the welding power sources 2a and 2b to a and 1b, and an arc 8 is generated between one of the consumable electrode wires 1a and the base material 7 and the deposited metal 9. Further, in the molten pool 10 generated by the arc 8, the trailing filler wire 1b
Insert the tip of the. At that time, a current Ia flowing through the consumable electrode wire 1a and a current I flowing through the filler wire 1b
The direction is opposite to that of b, and both currents Ia,
Since the magnetic fields generated around the wires 1a and 1b repel each other due to the action of Ib, the arc 8 is not biased to the filler wire 1b side behind the arc 8 to melt and scatter the filler wire 1b.

When performing the above welding, the changeover switch on the side of the welding power source 2b is operated in advance, so that the current Ib of the waveform shown in FIG. 2 with respect to the filler wire 1b, that is, shown in FIG. A current Ib having a constant current value similar to the constant current Ia supplied to the consumable electrode wire 1a.
, The repulsive force of the magnetic field generated around each of the wires 1a and 1b becomes constant regardless of the change in impedance of the base material 7. Therefore, the arc 8 generated by the consumable electrode wire 1a is not affected by the magnetic field to cause irregular runout, and the position suitable for arc welding, that is, the melting of the base metal 7 and the deposited metal 9 is prevented. In addition, the arc 8 can be positioned at a position where the tip of the subsequent filler wire 1b can be properly inserted into the molten pool 10, and efficient and proper arc welding can be performed.

On the other hand, unlike the above, when the current Ib having the waveform shown in FIG. 3 is supplied from the welding power source 2b to the filler wire 1b, when the current Ib (max) is reached, the filler wire 1b and the consumable electrode wire are The repulsive force between the magnetic fields generated around 1a and each of the two is maximum, but conversely, when the current is Ib (min), the repulsive force of the magnetic field is minimum. Since the repulsive force of the magnetic field regularly increases and decreases as in the above waveform, the distance by which the arc 8 is pushed forward changes regularly with the change in the repulsive force of the magnetic field. As a result, even if the consumable electrode wire 1a and the filler wire 1b are kept straight, the regular movement (deflection) of the arc 8 causes an operation state similar to that of weaving, which eliminates the undercut or melts the melted portion. It will help disperse heat.

In the embodiment shown in FIG. 1, one consumable electrode wire 1a and one filler wire 1b are used.
However, the present invention is not limited to this, and a plurality of filler wires 1b may be provided for one consumable electrode wire 1a to enhance the weaving effect. Moreover, in the arc welding machine of FIG.
The welding power source 2b is provided with a changeover switch so that the current Ib supplied to the filler wire 1b can be arbitrarily selected from one of the two types of waveforms, but the present invention is not limited to this. A welding power source 2b (corresponding to claims 1 and 3) for supplying only the current Ib as shown in FIG.
Welding power source 2b for supplying only the current Ib as shown in
(Corresponding to claims 2 and 4).

Further, in the present invention as claimed in claim 2 or claim 4, the current Ib to the filler wire 1b does not necessarily have to be the control current having the waveform as shown in FIG. The control current may be a sine wave or a triangular wave, or may be a pulse current. In addition, the present invention can be applied to welding of various metals such as iron, stainless steel, and aluminum alloys, and the material and type of the specific object to be welded does not matter.

[0023]

As can be understood from the above description, according to the consumable electrode type arc welding method of the present invention as set forth in claim 1, the filler wire flows into the filler wire due to various factors such as impedance of the base material. Since it is possible to appropriately prevent the current value from fluctuating irregularly, by stabilizing the repulsive force of the magnetic field generated around each of the filler wire and the consumable electrode wire, and eliminating the irregular deflection phenomenon of the arc. As a result, it is possible to fix the arc at a desired proper position, and it is possible to obtain a special effect that the arc welding can be performed with higher efficiency and better finish than ever.

According to the consumable electrode type arc welding method of the present invention as defined in claim 2, the position of the arc is moved regularly by making the current supplied to the filler wire into a predetermined waveform. Other than controlling the current waveform, it is possible to intentionally perform the same operation as the weaving operation without requiring any special control operation, so eliminate undercuts or dissipate heat as necessary. It is possible to easily perform arc welding with a better finish.

Further, according to the consumable electrode type arc welding machine according to the present invention as set forth in claims 3 and 4, the welding power source provided separately from the welding power source for the consumable electrode wire provides a predetermined amount for the filler wire. Since a constant current can be supplied, the effect of contributing to the proper implementation of the consumable electrode type arc welding method can be obtained.

[Brief description of drawings]

FIG. 1 is an explanatory view showing an example of a consumable electrode type arc welder according to the present invention.

FIG. 2 is an explanatory diagram showing an example of a current waveform supplied to each of a consumable electrode wire and a filler wire.

FIG. 3 is an explanatory diagram showing another example of a current waveform supplied to each of the consumable electrode wire and the filler wire.

FIG. 4 is an explanatory view showing an example of a conventional consumable electrode type arc welder.

[Explanation of symbols]

 1a Consumable electrode wire 1b Filler wire 2a, 2b Welding power source 5 Gas nozzle 7 Base metal 8 Arc 9 Weld metal 10 Weld pool

Claims (4)

[Claims] 1. A consumable electrode wire is supplied with an electric current to generate an arc, and a filler wire disposed behind the consumable electrode wire is melted while a current flowing in a direction opposite to a current flowing through the consumable electrode wire is applied. It is a consumable electrode type arc welding method of inserting into a pond and performing welding, wherein the filler wire is supplied with an electric current from a welding power source different from a welding power source for supplying power to the consumable electrode wire, and flows into the filler wire. A consumable electrode type arc welding method characterized in that constant current control is performed to keep a constant current value. 2. The consumable electrode type arc welding method according to claim 1, wherein the filler wire is supplied with a control current having a waveform in which an AC signal component is superimposed on a DC reference component. 3. A consumable electrode type arc welder comprising a consumable electrode wire for generating an arc, and a filler wire arranged in parallel with the consumable electrode wire, wherein the consumable electrode wire and the filler wire are provided. Welding power supplies for supplying currents whose current directions are opposite to each other are individually provided for both of them, and the welding power supply for supplying current to the filler wire has a constant current value flowing through the filler wire. A consumable electrode type arc welder characterized by being configured to perform current control. 4. The welding power source for supplying a current to the filler wire according to claim 3, wherein the current supplied to the filler wire is a control current having a waveform in which an AC signal component is superimposed on a DC reference component. Consumable electrode type arc welder characterized by being configured as follows.