JP3185071B2 - Consumable electrode type arc welding method and its welding machine - Google Patents

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 for 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 described in Japanese Patent Application Laid-Open No. 3-275280 has been developed and proposed. As shown in FIG. 4, this conventional arc welding method uses a consumable electrode wire 1a as a leading wire between a consumable electrode wire 1a and a filler wire 1b which are arranged side by side, so that the base material 7 and the weld metal 9 are separated. The arc 8 is generated at the same time, and the tip of the filler wire 1b as the following wire is inserted into the molten pool 10. Also, the consumable electrode wire 1 is supplied from the welding power source 2E.
A part of the welding current flowing through the base material 7 through the a is diverted to the filler wire 1b and joined to the welding power source 2E, and the directions of the current flowing through the consumable electrode wire and the filler wire 1b are opposite to each other. 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, so that the amount of power supplied to the consumable electrode wire 1a, that is, the heat input during welding, is increased significantly. In addition, the melting rate of the entire wire can be increased. Therefore, there is an advantage that even if the welding current is increased, even if it is an aluminum alloy or the like which is liable to cause puckering or welding distortion, welding with high work efficiency can be performed without causing such problems. If the directions of the currents (arrows a and b) flowing through the wires 1a and 1b are opposite, the wires 1a and 1b
The magnetic fields generated around each of b generate repulsive forces, and the arc 8 is appropriately pushed forward (in the direction of arrow B).
Even if both wires 1a and 1b are brought close to each other, filler wire 1b
Is not melted or scattered by the arc 8. Therefore, the filler wire 1b is replaced with the consumable electrode wire 1a.
, And the insertion into the molten pool 10 can be appropriately performed.

[0004]

However, in the above arc welding method, only a part of the welding current flowing through the base material 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, the current fluctuated irregularly. That is, the magnitude of the current flowing through the filler wire 1b depends on the welding power source 2E.
Is affected by the respective impedances from the cathode terminal to the base material 7 and the filler wire 1b, but the difference in the impedance is not always constant, but irregular due to changes in the welding location and various other 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 and decreased.

However, when the value of the current becomes unstable, the filler wire 1b and the consumable electrode wire 1a become unstable.
Since the repulsive force of the magnetic field generated around each of these changes irregularly, the position of the arc 8 also changes irregularly (deflects) due to the influence of the magnetic field. Can not be fixed to a certain place.
As a result, in the related art, the deflecting arc 8 causes the filler wire 1b behind it to be unduly melted, or the filler wire 1b is added to the molten pool 10 generated by the arc 8 when the arc 8 is excessively pushed forward. In some cases, it may not be possible to insert the steel properly, resulting in a problem such as a decrease in welding speed or a decrease in quality of a finished weld.

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

[0007]

The consumable electrode type arc welding method according to the present invention according to the first aspect of the present invention proposed to achieve the above object generates an arc by supplying a current to a consumable electrode wire. Along with the filler wire arranged behind the consumable electrode wire, a consumable electrode type arc welding method for welding by inserting the current into the molten pool while flowing a current in the opposite direction to the current flowing through the consumable electrode wire, When supplying a current from a welding power source different from a welding power source that supplies power to the consumable electrode wire, the filler wire controls the current flowing through the filler wire to a current waveform that changes at a gradual constant cycle. This is a consumable electrode type arc welding method.

According to a second aspect of the present invention, in the consumable electrode type arc welding method according to the first aspect of the present invention, an AC signal component is superimposed on a DC reference component on the filler wire. This is a method of supplying a control current having a varied waveform.

According to a third aspect of the present invention, there is provided a consumable electrode type arc welding machine for implementing the method of the first aspect. A consumable electrode type arc welding machine comprising: a filler wire arranged in parallel with an electrode wire, wherein both the consumable electrode wire and the filler wire are configured to supply currents whose current directions are opposite to each other. Welding power supplies are individually provided, and the welding power supply for supplying current to the filler wire is configured to control the current flowing through the filler wire to a current waveform that changes at a gradual constant cycle.

A consumable electrode type arc welding machine according to a fourth aspect of the present invention, which is proposed to carry out the method according to the second aspect, has the configuration according to the third aspect, wherein The welding power supply for supplying current to the filler wire is configured to make the current supplied to the filler wire 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 according to the first aspect of the present invention, the filler wire is welded separately from a 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 fluctuated at a gentle constant cycle, it has the same effect as operating the consumable electrode with the wiving operation, due to the impedance change of the base material and other parts, etc. It can be prevented that the repulsive force of the magnetic field generated around each of the filler wire and the consumable electrode wire fluctuates irregularly. Therefore, the position of the arc can be fixed to a position optimal for welding in relation to the position of the filler wire.

Further, in the consumable electrode type arc welding method according to the present invention, by supplying a control current having a desired waveform to the filler wire, a current value flowing through the filler wire is changed regularly. 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. Therefore, a so-called weaving operation or the like can be performed by moving the arc regularly by the repulsive force of the magnetic field. Note that the change in the position of the arc is performed regularly in accordance with the current waveform, and the conventional irregular movement of the arc due to a change in impedance or the like basically means that the purpose, operation function, and action of the arc are basically different. Are different. That is, the regular change in the position of the arc 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 effect as the present invention. It is.

Further, in the consumable electrode type arc welding machine according to the present invention described in each of claims 3 and 4, the waveform control for varying the current flowing through the filler wire at a gradual constant cycle can be performed. Claim 1 or Claim 2
The described consumable electrode type arc welding method can be appropriately performed.

[0014]

【Example】

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

Here, the consumable electrode wire 1a and the filler wire 1b are fed from the wire reels 3a, 3b to the feed roller 4a.
The gas nozzle 5 is provided so as to be able to be sequentially fed toward the base material by driving a and b, and each of its distal ends projects downward from the distal end opening of the gas nozzle 5. The gas nozzle 5
Is for discharging a desired shielding gas such as argon gas or carbon dioxide. The tips of the two wires 1a and 1b are arranged substantially parallel to each other at a small interval, and one of the consumable electrode wires 1a is located forward with respect to the welding progress direction (the direction of arrow A) and the other is filled with filler. Wire 1b
Is set to be located on the rear side. In addition to providing the filler wire 1b in a state parallel to the consumable electrode wire 1a, the filler wire 1b may be inclined, for example, within an angle range of about 20 ° with respect to the consumable electrode wire 1a.

Of the two welding power sources 2a and 2b, one of the welding power sources 2a has its anode side connected to the chip 6a for the consumable electrode wire 1a via the wiring L1 and its cathode side connected to the motherboard via the wiring L2. The arc 8 is generated between the consumable electrode wire 1a, the base material 7, and the weld 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 set in advance by a setting switch or the like. This constant current control is performed by, for example, causing the welding power supply 2a to perform a fidburk with an actual measured value of the current value or voltage value of the current Ia, and changing and controlling the voltage of the welding power supply 2a according to the feedback value. Incidentally, a power supply having a drooping characteristic may be used as the welding power supply 2a.

In contrast to the welding power supply 2a, the other welding power supply 2b has its cathode connected to the chip 6b for the filler wire 1b via the wiring L3 and its anode connected to the wiring L2 via the wiring L4. Have been. However,
The wiring L2 is grounded, and the welding power source 2b is configured to supply the filler wire 1b with a current Ib opposite to the current Ia flowing through the consumable electrode wire 1a. The welding power source 2b is configured to be able to supply the filler wire 1b by selecting one of two types of control currents having a waveform described later by operating a changeover switch or the like. That is, as the first example, as the control current having two waveforms, as shown in FIG. 2, 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 an example of FIG.
A constant current type having a waveform in which an AC waveform signal component is superimposed on a constant reference current value N as shown in FIG.
Is applied, and the welding power source 2b is configured to be able to supply both types of current by arbitrarily switching between them (however, FIGS. 2 and 3 show the absolute value of the current ignoring the polarity of the potential). It was done.) Also, in the welding power source 2b, the one of the first welding is performed so that the value of the current Ib actually flowing through the filler wire 1b has the waveform as described above without being affected by the change in the impedance of the base material 7 or the like. Like the power supply 2a, the power supply 2a is provided with feedback control means for an actually measured value of the current Ib.

[Example of method (corresponding to claims 1 and 2)]
Next, an embodiment 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 following wire.
A predetermined DC current is supplied from a welding power source 2a, 2b to the a, 1b, and an arc 8 is generated between one of the consumable electrode wires 1a, the base material 7, and the deposited metal 9. The molten pool 10 generated by the arc 8 has a filler wire 1
Insert the tip of At this time, the current Ia flowing through the consumable electrode wire 1a and the current Ia flowing through the filler wire 1b
b, the directions are opposite to each other, and these two currents Ia,
Since the magnetic field generated around the wires 1a and 1b by the action of Ib repels each other, the arc 8 does not bias the filler wire 1b behind and melt and scatter the filler wire 1b.

In the case of performing the above-mentioned welding, the current Ib having the waveform shown in FIG. 2 for the filler wire 1b, ie, the current Ib shown in FIG. A constant current Ib similar to the constant current Ia supplied to the consumable electrode wire 1a
Is supplied, the repulsive force of the magnetic field generated around each of the wires 1a and 1b is constant irrespective of the change in the impedance of the base material 7, and the like. Therefore, the arc 8 generated by the consumable electrode wire 1a is not affected by the magnetic field and irregularly oscillates, so that 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 appropriately inserted into the molten pool 10, and efficient and appropriate 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), the filler wire 1b and the consumable electrode wire The repulsive force between the magnetic field generated around 1a and each of the two becomes maximum, while the repulsive force of the magnetic field becomes minimum when the current is Ib (min). Since the repulsive force of the magnetic field increases and decreases regularly as in the above-described waveform, the distance that the arc 8 is pushed forward also changes regularly with the fluctuation of the repulsive force of the magnetic field. As a result, even when the consumable electrode wire 1a and the filler wire 1b are kept straight, the regular movement (run-out) of the arc 8 becomes an operation state similar to that of the weaving, and the undercut is eliminated or the molten portion is removed. It will help spread the heat.

In the embodiment shown in FIG. 1, one consumable electrode wire 1a corresponds to one filler wire 1b.
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. In the arc welding machine of FIG.
Although a changeover switch is provided in the welding power source 2b so that the current Ib supplied to the filler wire 1b can be arbitrarily selected to one of two types of waveforms, 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 FIG.
(Corresponding to claims 2 and 4).

Furthermore, in the present invention according to claim 2 or claim 4, the current Ib to the filler wire 1b does not necessarily need to be a control current having a waveform as shown in FIG. Sine wave or triangular wave control current, or, of course, a pulse current. In addition, the present invention is applicable to welding of various metals such as iron, stainless steel, and aluminum alloy, and the material and type of the specific welding target are not limited.

[0023]

As will be understood from the above description, according to the consumable electrode type arc welding method according to the present invention as set forth in claim 1, arc arc welding is performed in the same manner as in the case where the consumable electrode wire is operated by wiving. Since the irregular run-out phenomenon can be eliminated, the arc can be fixed to a desired and appropriate position, and a special effect that arc welding with higher efficiency and a better finish can be performed than before can be obtained. .

Further, according to the consumable electrode type arc welding method according to the present invention, the electric current supplied to the filler wire has a predetermined waveform, so that the position of the arc is moved regularly, Since the same operation as the weaving operation can be intentionally performed without any special control operation other than the control of the current waveform, it is necessary to eliminate undercuts and disperse heat as necessary. Thus, there is an advantage that arc welding with a better finish can be easily performed.

Further, according to the consumable electrode type arc welding machine according to the present invention, since the current which fluctuates at a gentle constant period can be supplied to the filler wire, The effect which can contribute to the proper implementation of the consumable electrode type arc welding method is obtained.

[Brief description of the drawings]

FIG. 1 is an explanatory view showing one embodiment of a consumable electrode type arc welding machine 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 welding machine.

[Description of Signs] 1a Consumable electrode wire 1b Filler wire 2a, 2b Welding power supply 5 Gas nozzle 7 Base material 8 Arc 9 Weld metal 10 Weld pool

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-57-72772 (JP, A) JP-A-59-16680 (JP, A) JP-A-59-16679 (JP, A) 122681 (JP, A) JP-A-4-1822071 (JP, A) JP-B-45-39931 (JP, B1) (58) Fields investigated (Int. Cl. ⁷ , DB name) B23K 9/173 B23K 9 / 073

Claims (4)

(57) [Claims] An arc is generated by supplying a current to a consumable electrode wire, and a filler wire disposed behind the consumable electrode wire is melted while supplying a current in a direction opposite to a current flowing in the consumable electrode wire. A consumable electrode type arc welding method for welding by inserting into a pond, wherein the filler wire, when supplying current from a welding power source different from a welding power source for supplying power to the consumable electrode wire ,
Changes the current flowing through the filler wire at a gradual
A consumable electrode type arc welding method, characterized in that the current waveform is controlled so as to be changed. 2. The consumable electrode type arc welding method according to claim 1, wherein a control current having a waveform in which an AC signal component is superimposed on a DC reference component is supplied to the filler wire. 3. A consumable electrode type arc welding machine comprising: a consumable electrode wire for generating an arc; and a filler wire juxtaposed to the consumable electrode wire, wherein the consumable electrode wire and the filler wire are connected to each other. Both are individually provided with welding power supplies for supplying currents whose current directions are opposite to each other, and the welding power supply for supplying current to the filler wire moderates the current flowing through the filler wire.
A consumable electrode type arc welding machine characterized in that the current waveform is controlled to change at a constant cycle . 4. The welding power source for supplying 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. A consumable electrode type arc welding machine characterized in that: