JPH05253671A - Consumable electrode arc welding method and welding machine thereof - Google Patents

Abstract

PURPOSE:To increase the melting rate of a filler wire and to perform efficient arc welding without causing trouble such as an arc being pushed away ahead farther than necessity by resilience of a magnetic field generated between a consumable electrode wire and the filler wire even when high melting point materials are welded together. CONSTITUTION:The consumable electrode arc welding method where a pulse current 1a is supplied to the consumable electrode wire 1a to generate the arc 8 and the filler wire 1b which is arranged in the rear of the consumable electrode wire 1a and provided so that a pulse current 1b in the opposite direction to a current carried to the consumable electrode wire 1a is carried thereto is inserted into a molten pool 10 is provided. The pulse current to generate resistance heat on this filler wire 1b is then supplied to the filler wire 1b in an opposite phase state to phase of the pulse current carried to the consumable electrode wire 1a.

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 suitable for welding metals having a relatively high melting point such as iron and stainless steel, 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 disclosed in Japanese Patent Laid-Open No. 3-275280 has been developed and proposed. In this conventional arc welding method, as shown in FIG. 3, of the two consumable electrode wires 1a and the 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. The consumable electrode wire 1a and the filler wire 1b are connected to the welding power source 2E so that the currents flowing through them are in opposite directions (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, when the above-mentioned arc welding method is applied to welding of iron or stainless steel, the following problems occur. That is, since the melting point of iron, stainless steel and the like is considerably higher than that of aluminum alloy and the like, even if the filler wire 1b such as an iron alloy used for welding is inserted into the molten pool 10, the temperature of the molten pool 10 and the filler Due to the small temperature difference from the melting point of the wire 1b, the filler wire 1b is difficult to melt, and its melting rate becomes considerably slow. Therefore, the welding work efficiency is considerably reduced as compared with the case of aluminum alloy or the like. Incidentally, as a measure for solving such a difficulty, for example, by increasing the electric current that is guided from the consumable electrode wire 1a through the base material 7 to the filler wire 1b, resistance heat is generated in the filler wire 1b, and the filler wire 1b is generated. It is conceivable to increase the melting rate by heating the. However, when such a means is applied, the currents flowing through the consumable electrode wire 1a and the filler wire 1b both increase, and the repulsive force of the magnetic field generated around each of these wires 1a, 1b also increases. The problem is that it is pushed too far forward and proper arc welding cannot be performed.

The present invention has been proposed in view of the above points, and even when welding a material having a high melting point,
The melting speed of the filler wire is increased and efficient arc welding is performed without causing the problem that the arc is pushed forward more than necessary due to the repulsive force of the magnetic field generated between both the consumable electrode wire and the filler wire. Its purpose is to make it happen.

[0006]

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 a pulse current to generate an arc. A consumable electrode type arc welding method of inserting a filler wire, which is arranged behind the consumable electrode wire and provided so that a current flowing in a direction opposite to the current flowing through the consumable electrode wire, into the molten pool, In this method, a pulse current for generating resistance heat in the filler wire is supplied to the filler wire in a phase state opposite to the phase of the pulse current flowing in the consumable electrode wire.

Further, the consumable electrode type arc welding machine according to the present invention as claimed in claim 2 which is proposed to carry out the above method, includes a consumable electrode wire for generating an arc, and the consumable electrode wire. A consumable electrode type arc welder provided with a filler wire provided, wherein both the consumable electrode wire and the filler wire have a welding power source for supplying pulse currents whose current directions are opposite to each other. The pulse current supplied to the consumable electrode wire and the pulse current supplied to the filler wire are individually provided and are configured to have opposite phases.

[0008]

In the consumable electrode type arc welding method according to the present invention as set forth in claim 1, the pulse current flowing through the consumable electrode wire and the pulse current flowing through the filler wire have opposite phases. Therefore, when a large current flows through either one of the consumable electrode wire and the filler wire to generate a magnetic field with a large magnetic force, the other side does not flow a large current and a weak magnetic force. The magnetic field of is only generated. Therefore, the fact that the repulsive force of both magnetic fields increases when a large current is applied to the filler wire is eliminated, and the repulsive force between the magnetic fields generated around both the consumable electrode wire and the filler wire is stable. Therefore, the arc generated by the consumable electrode wire is
It is possible to solve the problem of being excessively pushed forward due to the influence of those magnetic fields. Then, as described above, when the amount of pulse current supplied to the consumable electrode wire is reduced, the amount of electric power to the filler wire can be increased. Therefore, the amount of resistance heat of the filler wire is increased, and the filler wire is heated to a high temperature. be able to. Therefore, the melting of the filler wire inserted in the molten pool is promoted, and the welding speed of the wire can be increased even in the welding of high melting point metal.

Further, in the consumable electrode type arc welding machine according to the present invention as set forth in claim 2, the consumable electrode wire and the filler are supplied from welding power sources individually provided for both the consumable electrode wire and the filler wire. The pulse currents of opposite phases can be supplied to the wires, respectively.
The consumable electrode type arc welding method described can be appropriately implemented.

[0010]

【Example】

[Embodiment of apparatus (corresponding to claim 2)] First, an embodiment of a consumable electrode type arc welder according to the present invention will be described. Figure 1
FIG. 3 is an explanatory diagram showing its schematic configuration. The arc welding machine shown in the figure has a consumable electrode wire 1 for generating an arc.
a, a filler wire 1b for inserting the tip portion into the molten pool, welding power supplies 2a, 2b for individually supplying a predetermined pulse current to each of these wires 1a, 1b, and various equipment described later. ing.

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. On the other hand, the other welding power source 2b
The cathode side of the filler wire 1b via the wiring L3.
And the anode side thereof is connected to the wiring L2 via the wiring L4. However, this wiring L2 is grounded, and the current I flowing from the welding power source 2b to the consumable electrode wire 1a with respect to the filler wire 1b.
The current Ib in the opposite direction to a is configured to be able to be supplied.
Then, these two welding power sources 2a and 2b are, as shown in FIG. 2, a pulse current Ia flowing through the consumable electrode wire 1a.
And the pulse current Ib flowing through the filler wire 1b,
The pulse currents are supplied in synchronization with each other so that their phases are opposite to each other. However,
The explanatory diagram of FIG. 2 illustrates the absolute value of the current ignoring the positive / negative of the potential.

[Example of Method (Corresponding to Claim 1)] 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 pulse current is supplied from a welding power source 2a, 2b to a and 1b, and an arc 8 is generated between one consumable electrode wire 1a and the base material 7 and the weld metal 9. In addition, the molten filler pool 10 generated by the arc 8 has a trailing filler wire 1
Insert the tip of b. At that time, the consumable electrode wire 1a
Of the current Ia flowing through the filler wire 1b and the current Ib flowing through the filler wire 1b are opposite in direction.
Since the magnetic fields generated around the wires 1a and 1b repel each other by the action of a and Ib, the arc 8 is biased toward the filler wire 1b side behind the arc 8 and the filler wire 1b is not melted and scattered. Absent.

As described above with reference to FIG. 2, since the pulse currents Ia and Ib flowing through the wires 1a and 1b have opposite phases, the consumable electrode wire 1a has a large current. When the pulse current Ia (max) of the above flows and a magnetic field with a large magnetic force is generated around it,
On the other hand, only the small pulse current Ib (min) is flowing in the other filler wire 1b, and the magnetic force of the magnetic field generated on the filler wire 1b side is weak. On the contrary, when only a small current Ia (min) flows in one consumable electrode wire 1a, a large current Ib (max) flows in the other filler wire 1b.
It is possible to prevent a large variation in the repulsive force between the magnetic fields generated in the wires 1a and 1b. Therefore, since the repulsive force of the magnetic field between the wires 1a and 1b can be stabilized, the arc 8 will not be excessively pushed forward due to the adverse effect of the magnetic field, and the arc 8 suitable for welding can be obtained. Be done.

Then, as described above, the filler wire 1
Since a large current Ib (max) can be intermittently supplied to b, the filler wire 1b thereby generates high-temperature resistance heat and is heated to a high temperature. Therefore, even when high-melting-point iron, stainless steel, or the like, in which the filler wire 1b has a slow melting rate only by being inserted into the molten pool 10, the resistance heat of the filler wire 1b promotes its melting,
It is possible to make the melting rate very fast.

In the present invention, needless to say, the object to be welded is not limited to iron, stainless steel, etc., and can be applied to any of those having a melting point higher or lower than these. The arc welding method according to the first aspect of the present invention is not limited to the use of the arc welding machine according to the second aspect.

[0017]

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 consumable electrode wire and the filler are used by using the pulse currents having opposite phases. By stabilizing the repulsive force of the magnetic field generated between the wire and the wire, it is possible to prevent the arc from being excessively pushed forward due to the adverse effect of the magnetic field, and at the same time increase the amount of power supplied to the filler wire. And because the resistance heat can accelerate the melting of the filler wire,
Even in the case of welding a material having a high melting point, which is difficult to melt the filler wire, it is possible to obtain a special effect of increasing the melting speed of the filler wire and performing high-speed and efficient arc welding. Moreover, in the present invention, the above effects are obtained without impairing the advantages of the conventional consumable electrode type arc welding method using the consumable electrode wire and the filler wire, and preferable welding with less welding distortion can be realized. There are advantages. Further, according to the consumable electrode type arc welding machine of the present invention as set forth in claim 2, anti-phase pulse currents are respectively supplied from two welding power sources individually provided to both the consumable electrode wire and the filler wire. Since it can be supplied, it contributes to the proper implementation of the consumable electrode type arc welding method.

[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 a pulse current supplied to both a consumable electrode wire and a filler wire.

FIG. 3 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 material 8 Arc 9 Weld metal 10 Weld pool Ia, Ib Pulse current

Claims (2)

[Claims] 1. A consumable electrode wire is supplied with a pulse current to generate an arc, and is arranged behind the consumable electrode wire so that a current in a direction opposite to the current flowing through the consumable electrode wire flows. A consumable electrode type arc welding method of inserting a filler wire into a molten pool, wherein the filler wire has a pulse current for generating resistance heat in the filler wire, and the phase of the pulse current flowing through the consumable electrode wire is A consumable electrode type arc welding method characterized by supplying in opposite phase states. 2. 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 pulse currents whose current directions are opposite to each other are individually provided on both of them, and the phase of the pulse current supplied to the consumable electrode wire and the pulse current supplied to the filler wire is A consumable electrode type arc welder characterized by being configured to have opposite phases.