JP6004623B2 - Two-electrode differential welding method - Google Patents

Description

  In the present invention, when fillet welding is performed using two electrodes, a leading electrode and a trailing electrode, the amount of heat input is adjusted using an external heat source that is different from the welding to prevent the to-be-welded member from collapsing. The present invention relates to a left-right difference welding method.

T-type fillet welding is often performed in structures such as shipbuilding and bridges. At this time, in order to improve the efficiency of the welding operation, it is common to place electrodes on both sides of the web material and perform fillet welding simultaneously from both sides.
When such two electrodes are used at the same time, the two electrodes are separated by a certain distance in order to prevent welding defects such as blowholes, and the welding currents at the electrodes on both sides are made equal to ensure leg length. Yes.

  However, when performing welding simultaneously with two electrodes, if the amount of welding and the amount of heat input on the leading side and the trailing side are equal, the penetration on the trailing side is larger than that on the leading side due to the influence of heat input on the leading side. Therefore, there is a drawback that the web material is not welded perpendicularly to the other member to be welded and falls to the trailing side.

  For this reason, as a means to solve this, by reducing the amount of heat input by the trailing electrode (for example, changing the wire protrusion length or wire diameter, that is, reducing the welding current), the penetration depth on both sides is made uniform, A two-electrode welding method that prevents the web material from collapsing has been proposed (see, for example, Patent Document 1).

JP-A-9-1341

However, in actual welding, as shown in FIG. 2, the feeding point 5 in the contact tip 4, that is, the wire protrusion length L always fluctuates due to the bending of the welding wire 3 and the wear of the contact tip 4.
For example, as shown in FIG. 3, the welded member 12 generally has a non-uniform gap called a gap between the welded member 11 and the other welded member 11 due to manufacturing errors. When there is a gap 13, construction is performed while adjusting the welding current in order to secure a predetermined leg length.
That is, in the construction work, even if an attempt is made to suppress the amount of heat input by the electrodes and to control the penetration depth on the left and right sides, adjustments to deal with member errors typified by the gap 13 and the like, and current due to wear of the contact tips 4 There was a problem that it was difficult to make the penetration depths on both sides uniform.

  The present invention has been made to solve the above-described problems, and prevents the member to be welded 12 from collapsing by adjusting the amount of heat input with an external heat source different from welding and controlling the penetration depth. An object of the present invention is to provide a two-electrode left-right difference welding method.

The two-electrode difference welding method according to the present invention is a two-electrode welding method in which fillet welding is performed simultaneously from both sides of a member to be welded using a leading electrode and a trailing electrode.
During construction of the fillet welding, by using an external heat source other than welding, the difference between the amount of heat input on the leading electrode side and the amount of heat input on the trailing electrode side is obtained, so that both sides of the welded member are melted. It is characterized by uniform depth.

  Here, in the present invention, the amount of heat input on the leading electrode side refers to the total amount of heat input that is the sum of the amount of heat input from welding by the leading electrode and the amount of heat input from the external heat source. Therefore, when there is no external heat source on the leading electrode side, the heat input amount on the leading electrode side is only the heat input amount of welding by the leading electrode. Similarly, the amount of heat input on the trailing electrode side is the total amount of heat input that is the sum of the amount of heat input from welding by the trailing electrode and the amount of heat input from the external heat source. Therefore, when there is no external heat source on the trailing electrode side, the heat input amount on the trailing electrode side is only the heat input amount of welding by the trailing electrode.

  In the two-electrode left-right difference welding method of the present invention, as an external heat source, one or both of a heat source for heating the welded portion on the preceding electrode side and a cooling source for cooling the welded portion on the subsequent electrode side are used. It is to be provided.

  Further, in the two-electrode left-right difference welding method of the present invention, by measuring the temperature of a specific part of the member to be welded by a temperature sensor, the amount of heat input on the leading electrode side based on the measured temperature is made constant, and The amount of cooling on the row electrode side is changed.

  Further, in the two-electrode left-right difference welding method of the present invention, the specific part of the welded member is a position on the back side of the welded member of the welded part on the preceding electrode side, and the preceding electrode and the succeeding electrode are It is a position between.

  According to the present invention, during construction of fillet welding of a member to be welded, using an external heat source other than welding, making a difference between the heat input amount on the preceding electrode side and the heat input amount on the subsequent electrode side; Therefore, even if there is a gap, wear of consumable parts, etc., there is an effect that the to-be-welded member can be prevented from falling without changing the amount of heat input by an electrode that is difficult to manage.

It is a figure which shows the outline | summary of the 2 electrode left-right difference welding method in the form of construction of this invention, (a) is a top view, (b) is a front view. It is sectional drawing of the contact tip part of an electrode. It is a figure which shows the gap by the manufacture error of a to-be-welded member, (a) is a front view, (b) is a side view.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

FIG. 1 is a diagram showing an outline of a two-electrode left-right difference welding method in the embodiment of the present invention.
As shown in FIG. 1, the leading electrode 1 and the trailing electrode 2, both of which are consumable electrodes, are arranged on the welded member 12, for example, on the left side and the right side of FIG. 1 with a predetermined distance S between them. . The member to be welded 12 is erected on the other member to be welded 11 and is fillet welded simultaneously from both sides of the member to be welded 12 by the leading electrode 1 and the trailing electrode 2.
The leading electrode 1 is an electrode positioned at the head of the welding progress direction (the direction of the arrow), and is automatically fed so that the consumable electrode welding wire 3a has a required protruding length. The trailing electrode 2 is arranged at a position separated from the leading electrode 1 by a predetermined distance S, and similarly, the consumable electrode welding wire 3b is automatically fed so as to have a required protruding length. ing. Note that the types of the welding wires 3a and 3b (solid wire, cored wire, etc.) and wire diameter may be the same type, the same diameter, or different combinations of different diameters.

  Further, a heat source 6 for heating the welded portion 10a is provided on the leading electrode 1 side. The heat source 6 performs heating by, for example, a gas burner or high-frequency heating. On the other hand, a cooling source 7 for cooling the welded portion 10b is provided on the trailing electrode 2 side. The cooling source 7 is cooled by, for example, spraying compressed air or a contact-type water-cooled copper plate. For example, the heat source 6 and the cooling source 7 are mounted on a welding cart (not shown) (a cart that moves along the member to be welded 12) together with the welding torches of the leading electrode 1 and the trailing electrode 2, and are moved manually or automatically. Can do. Note that both the heat source 6 and the cooling source 7 may be used, or one of them may be used.

  Further, a temperature sensor 8 (for example, an infrared sensor) that detects the temperature of the member to be welded 12 is installed on the trailing electrode 2 side. The temperature sensor 8 is also installed on the welding carriage. This temperature sensor 8 measures the temperature of a specific part of the member 12 to be welded. That is, since it is desired to know the heat input due to the propagation of the welding heat of the leading electrode 1, that is, the temperature rise of the member before welding on the trailing electrode 2 side, the temperature sensor 8 is disposed on the trailing electrode 2 side. Here, the specific part refers to a position between the preceding electrode 1 and the succeeding electrode 2 on the back side of the welded member 12 of the welded portion 10a on the preceding electrode 1 side.

Next, the effect | action of this 2 electrode left-right difference welding method is demonstrated.
The member to be welded 12 is fillet welded simultaneously from both sides by the leading electrode 1 and the trailing electrode 2. During this welding operation, the welded portion 10a is heated by a heat source 6 such as a burner provided on the preceding electrode 1 side, the amount of heat input is adjusted, and the penetration depth is controlled. In addition, during welding work, the operator increases or decreases the welding current depending on the gap, so the amount of heating by the heat source 6 is adjusted accordingly. That is, when the gap is large, the amount of heat input by welding is increased by adjusting the welding speed to be slow or the welding current to be increased. Therefore, in this case, the total heat input (the sum of the welding heat input and the heating amount of the heat source 6) is adjusted to be constant by reducing the heating amount by the heat source 6.

  On the other hand, on the side of the trailing electrode 2, the total heat input is adjusted by cooling the welded portion 10 b by blowing compressed air from the cooling source 7, and the penetration depth is controlled. The cooling amount is determined based on the temperature information measured by the temperature sensor 8 and the amount of heat input by the succeeding electrode. The relationship between the measured temperature of a specific part, the amount of heat input and the amount of cooling by the electrode on the following side is obtained in advance as a database, and the amount of cooling is adjusted by referring to this database during welding. .

In the present invention, during fillet welding as described above, an external heat source is used to make a difference between the total heat input on the leading electrode 1 side and the total heat input on the trailing electrode 2 side. The penetration depth is made uniform, and the to-be-welded member 12 is prevented from falling. For example, by making the total heat input on the leading electrode 1 side constant and changing the cooling amount on the trailing electrode 2 side, a difference is made in the total heat input on the leading and trailing.
Therefore, according to the present invention, it is not the amount of heat input by the unstable and difficult to adjust electrode, but the amount of heat input by the external heat source 6 or the cooling source 7, so the influence of manufacturing errors of members and the degree of wear of consumable parts is affected. Even when there is, it is possible to reliably prevent the member to be welded from falling.

DESCRIPTION OF SYMBOLS 1 Leading electrode 2 Subsequent electrode 3a, 3b Welding wire 6 Heat source 7 Cooling source 8 Temperature sensor 10a, 10b Welding part 11, 12 Member to be welded

Claims (1)

In a two-electrode welding method in which fillet welding is performed simultaneously from both sides of a member to be welded using a leading electrode and a trailing electrode,
During construction of the fillet welding, by using an external heat source other than welding, the difference between the amount of heat input on the leading electrode side and the amount of heat input on the trailing electrode side is obtained, so that both sides of the welded member are melted. The depth is uniform ,
As the external heat source, one or both of a heat source for heating the welded portion on the leading electrode side and a cooling source for cooling the welded portion on the following electrode side are provided,
By measuring the temperature of the specific part of the member to be welded by the temperature sensor, the amount of heat input on the leading electrode side based on the measured temperature is made constant, and the cooling amount on the trailing electrode side is changed,
The specific part of the member to be welded is a position between the preceding electrode and the succeeding electrode at a position on the back side of the welded member of the welded portion on the preceding electrode side. Differential welding method.

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