JP6792196B2 - Welding equipment and welding method - Google Patents

Description

The present invention relates to a welding device and a welding method using a non-consumable electrode, and has a function of automatically detecting and imitating a groove-shaped welded portion (welding line) between one object to be welded and the other object to be welded. It relates to a welding device and a welding method having (a function similar to "weld line automatic copying" defined in robot welding).

Since the arc is stable in TIG welding and plasma welding using the non-consumable electrodes described above, it is possible to obtain a well-shaped and good-quality weld bead in the case of copy welding using an arc sensor.

Conventionally, as a welding apparatus (TIG welding apparatus) using the non-consumable electrode described above, for example, there is one described in Patent Document 1.
The groove copying welding device described in Patent Document 1 has a welding torch having an electrode whose tip is cut diagonally to deflect an arc, a rotation mechanism for rotating the electrode around an axis, and an oscillating operation on the welding torch. It is equipped with an oscillating mechanism to perform the operation and a control unit. In this control unit, by adopting AVC (Arc Voltage Control), the distance (arc length) between the obliquely cut electrode tip and groove of the electrode of the welding torch is controlled to be kept constant.

In this groove copying welding device, the electrode tip is always arranged on the side where the oscillating welding torch advances. Then, when the distance from the electrode tip of the welding torch to the groove becomes short in the vicinity of the groove wall at the groove, the welding torch is moved in the direction away from the groove by AVC, and the amount of movement of the welding torch is increased. When the set threshold is reached, it is recognized as a groove wall, and the welding torch is made to perform an oscillating operation in the opposite direction to the previous one.

In this groove copying welding device, an electrode whose tip is obliquely cut so that the arc can be deflected is used, and the electrode tip of this electrode is always located on the advancing side of the welding torch that operates oscillating. By doing so, it is possible to avoid the occurrence of a situation in which the electrodes interfere with the groove wall even during copy welding of a narrow groove having a small groove angle.

Japanese Unexamined Patent Publication No. 2015-024425

However, in the groove copying welding device described above, it is assumed that one object to be welded and the other object to be welded to each other by welding are made of the same material and the groove angle between the two is the same. There is. That is, although any groove wall of the groove can be reliably recognized, the melting conditions such as wettability due to the difference in the melting point and groove angle of one object to be welded and the other object to be welded are different. The position recognized as a groove wall is also different. In this way, when the positions recognized as the groove wall are different, the electrodes are too close to the groove wall to come into contact with each other, or are too far from the groove wall to cause poor welding.

The present invention has been made to solve the above-mentioned conventional problems. For example, in groove copying welding, even if the melting conditions of the pair of groove walls are different, any opening is made. It is an object of the present invention to provide a welding apparatus and a welding method capable of performing follow-up welding at an appropriate position even on a front wall.

A first aspect of the present invention is to cross a rod-shaped non-consumable electrode having a diagonally cut electrode tip and a groove-shaped welded portion between one object to be welded and the other object to be welded to each other by welding. An electrode drive mechanism that reciprocates the non-consumable electrode and reciprocates the non-consumable electrode along the longitudinal direction to approach and separate the groove-shaped welded portion, and a rotation mechanism that rotates the non-consumable electrode around the axis. The rotation mechanism is controlled so that the tip of the electrode is arranged on the traveling side in the reciprocating movement of the non-consumable electrode in the direction across the groove-shaped welded portion by the electrode drive mechanism, and AVC of the non-consumable electrode is performed. A control unit is provided, in which the non-consumable electrode moving in a direction crossing the groove-shaped welded portion is close to one groove wall side and the other groove wall side of the groove-shaped welded portion. The welding conditions of the one groove wall and the other groove wall for moving the non-consumable electrode along the longitudinal direction of the non-consumable electrode in a direction away from the groove-shaped welded portion by the AVC, and the non-consumable electrode. As a configuration in which the respective thresholds of the one groove wall and the other groove wall are set so that the non-consumable electrode moves toward the groove wall in the opposite direction when the movement amount of the electrode is reached. There is.

A second aspect of the present invention is such that the one work piece to be welded and the other work piece to be welded are metals of different types.

A third aspect of the present invention is that when the electrode drive mechanism cannot reciprocate the non-consumable electrode in the direction across the groove-shaped weld, the non-consumable electrode Only the rotation by the rotation mechanism and the reciprocating movement by the electrode drive mechanism to approach and separate the groove-shaped welded portion in the direction along the longitudinal direction of the non-consumable electrode are performed.

In the fourth aspect of the present invention, one groove wall and the other groove wall of the groove-shaped welded portion have a vertical positional relationship with each other, or a groove wall portion having a vertical positional relationship, respectively. It is configured to include.

A fifth aspect of the present invention has a configuration in which the angles of one groove wall and the other groove wall of the groove-shaped welded portion with respect to the groove bottom are different from each other.

In a sixth aspect of the present invention, the one work piece to be welded and the other work piece to be welded are joined to each other by fillet welding, and the groove-shaped welded portion is formed between the one work piece to be welded and the other work piece to be welded. It is configured to be the inside corner.

On the other hand, a seventh aspect of the present invention is to cross a non-consumable electrode having a rod-shaped electrode tip cut diagonally across a groove-shaped welded portion between one workpiece and the other workpiece to be joined to each other by welding. When the non-consumable electrode is reciprocated in the direction and the non-consumable electrode is reciprocated along the longitudinal direction to approach and separate from the groove-shaped welded portion, the non-consumable electrode is moved to the advancing side in the reciprocating movement in the direction across the groove-shaped welded portion. When the non-consumable electrode is arranged and the non-consumable electrode is AVC, and the non-consumable electrode moving in a direction crossing the groove-shaped welded portion approaches one groove wall of the groove-shaped welded portion, the non-consumable electrode is said. Based on the welding conditions set for one groove wall, the non-consumable electrode is moved by the AVC in a direction away from the groove-shaped welded portion along the longitudinal direction of the non-consumable electrode to form the non-consumable electrode. When the amount of movement reaches the threshold value set for the one groove wall, the non-consumable electrode is made to perform an operation toward the other groove wall, and the non-consumable electrode that moves in a direction crossing the groove-shaped welded portion is said. At the stage of approaching the other groove wall of the groove-shaped welded portion, the non-consumable electrode is attached to the other groove wall by the AVC based on the welding conditions set separately from the one groove wall. The non-consumable electrode is moved along the longitudinal direction in a direction away from the groove-shaped welded portion, and when the amount of movement of the non-consumable electrode reaches a threshold set separately for the other groove wall. The consumable electrode is configured to perform an operation toward the one groove wall.

According to the welding apparatus according to the present invention, for example, in groove copying welding, even if the melting conditions of the pair of groove walls are different, copying welding is performed at an appropriate position on any groove wall. It has the very good effect that it is possible.

It is the schematic block diagram (a) of the welding apparatus which concerns on one Embodiment of this invention, the enlarged side view (b), and the enlarged front explanatory view (c) which show the other form example of the electrode used in the welding apparatus. In the enlarged cross-sectional explanatory views (a) and (b) of the groove showing the oscillating operation of the electrode when performing follow-up welding to the groove between the objects to be welded which are different types of metals by the welding apparatus of FIG. is there. It is a partially enlarged plane explanatory view (a), (b) of the groove corresponding to FIGS. 2 (a) and 2 (b), respectively. It is a time chart of groove follow-up welding by the welding apparatus of FIG. An enlarged cross-sectional explanatory view of a groove showing the operation of an electrode when performing follow-up welding to a narrow groove between one object to be welded and the other object to be welded by the welding apparatus according to another embodiment of the present invention. is there. Description of an enlarged cross-sectional view of a groove showing the operation of an electrode when performing follow-up welding to a lateral groove between one object to be welded and the other object to be welded by the welding apparatus according to still another embodiment of the present invention. It is a figure. An electrode for performing follow-up welding to a groove in which the angles of the groove walls between one object to be welded and the other object to be welded are different from each other by the welding apparatus according to still another embodiment of the present invention. It is an enlarged cross-sectional explanatory view of the groove which shows the operation. An enlarged cross-sectional explanatory view (a), which shows the operation of the electrode when one object to be welded and the other object to be welded are joined by fillet welding having a large leg length by the welding apparatus according to still another embodiment of the present invention. b). It is an enlarged cross-sectional explanatory view which shows the operation of the electrode when one object to be welded and the other object to be welded are joined by fillet welding with a small leg length by the welding apparatus according to still another embodiment of the present invention.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
1 to 4 show a welding apparatus according to an embodiment of the present invention. This embodiment shows a case where the welding apparatus and welding method according to the present invention are adopted for copying welding of Ni-based alloy steels and SUSs having different types (melting points), and in this embodiment, the welding device and the welding method are in a downward posture. The case where the follow-up welding is performed on the grooves having the same groove angle of the pair of groove walls (groove walls) is shown.

As shown in FIG. 1A, the copy welding device 1 which is an automatic TIG welding device has a groove (groove) between one object to be welded (Ni-based alloy steel) Wn and the other object to be welded (SUS) Ws. Welded portion) A traveling portion 3 that moves on a rail 2 arranged along Wa, an elevating portion 5 that moves up and down along a vertical guide 4 arranged in the vertical direction 3 and the elevating portion. The slider 7 that moves along the lateral guide 6 arranged in the direction across the groove Wa in 5, the welding torch 8 supported by the slider 7, and the welding torch 8 and the objects to be welded Wn, Ws are connected to each other. In addition to the welding power supply 9 and the control unit 10, a potential meter (not shown) for measuring the amount of change in the axial direction of the welding torch 8 required for the AVC of the control unit 10 described later is provided. The copy welding device 1 is not limited to the automatic TIG welding device, and may be a plasma welding device.

As shown in the enlarged circle of FIG. 1, the columnar tungsten electrode 11 located at the tip of the welding torch 8 has its tip diagonally cut at an angle of θ with respect to the axis, and the cut surface 11a The lower end of the electrode tip 11b is set so that the arc Ar is deflected along the cut surface 11a instead of directly below.
As electrodes to be arranged at the tip of the welding torch 8, as shown in FIGS. 1 (b) and 1 (c), two cut surfaces 11c and 11c formed by cutting the tip diagonally and then cutting into a V shape are provided. The electrode 11A having the electrode 11A may be adopted.

Here, the angle θ with respect to the axis of the cut surface 11a of the electrode 11 whose tip is cut diagonally is set in consideration of the directivity and concentration of the arc Ar generated from the electrode tip 11b located at the lower end of the cut surface 11a. It is desirable that the temperature is 30 ° to 60 °, and more preferably 45 °.
Reference numeral 12 in FIG. 1 is a welding wire, and reference numeral 13 is a wire holder.

In this embodiment, an electrode drive mechanism is configured by an elevating portion 5 that moves up and down along a vertical guide 4 in the vertical direction and a slider 7 that moves along a horizontal guide 6, and the slider 7 has a columnar shape together with a welding torch 8. A rotation mechanism for rotating the tungsten electrode 11 around the axis is built-in.

At this time, as shown in FIG. 3, the electrode 11 whose tip is obliquely cut is along the groove Wa in order to ensure the directivity of the arc Ar to the groove walls Wnb and Wsb and the meltability of the welding wire 12. It is necessary to rotate the rotation angle α with respect to the direction, and the rotation angle α is preferably 15 ° to 45 °, and more preferably 30 °. However, if a mechanism capable of adjusting the welding wire 12 to the position of the arc Ar and supplying the welding wire 12 can be provided, the rotation angle α is set to 45 ° to 90 °, which increases the detectability of the groove walls Wnb and Wsb. May be good.

The control unit 10 gives a speed command to the traveling unit 3 to control the welding speed of the welding torch 8 with respect to the groove Wa between the objects to be welded Wn and Ws, and the elevating unit 5 and the slider 7 constituting the electrode drive mechanism. By giving a command to each of the above, the welding torch 8 moving along the groove Wa is made to perform an oscillating operation in the direction across the groove Wa.

Further, as shown in FIG. 2, the control unit 10 controls the rotation mechanism so that the electrode tip 11b of the electrode 11 is always positioned on the side (arrow direction side) where the welding torch 8 oscillating by the operation of the electrode drive mechanism advances. It is designed to do.

Further, in the control unit 10, AVC (Arc Voltage Control) that keeps the length of the arc Ar (the height of the welding torch 8) constant is adopted for the control of the groove copying.
This AVC utilizes the fact that the arc voltage in TIG welding and plasma welding changes depending on the length of the arc Ar. That is, when the distance between the electrode tip 11b of the electrode 11 and the objects Wn and Ws to be welded (the length of the arc Ar) becomes short and the measured arc voltage becomes lower than the reference voltage, the welding torch 8 is raised. When the arc voltage is increased, while the distance between the electrode tip 11b of the electrode 11 and the objects to be welded Wn, Ws becomes long and the measured arc voltage becomes higher than the reference voltage, the welding torch 8 is lowered to arc. By reducing the voltage, the height of the welding torch 8 is kept constant.

Specifically, as shown in FIG. 2A, the oscillating welding torch 8 approaches one groove wall Wnb (or the other groove wall Wsb) in the groove Wa to generate an arc Ar. When the position changes from the distance h between the electrode tip 11b and the groove bottom Wc to the distance h1 between the electrode tip 11b and the groove wall Wnb (or the other groove wall Wsb), one groove wall Wnb ( Alternatively, the welding torch 8 is moved along the longitudinal direction of the electrode 11 in the direction away from the groove Wa (upward in FIG. 2A) based on the welding conditions set for the other groove wall Wsb). It is designed to control the electrode drive mechanism.

Then, in the control unit 10, when the amount of movement of the welding torch 8 by the AVC reaches a threshold value set in advance on one groove wall Wnb (or the other groove wall Wsb), the rotation mechanism is operated to operate the electrode 11. As shown in FIG. 2B, the welding torch 8 is controlled so as to perform an oscillating operation in the opposite direction to the previous one by reversing it around the axis.

The welding conditions and thresholds for the one groove wall Wnb and the other groove wall Wsb are set for each groove wall Wnb and Wsb so that the weldability can be maximized within the range where the weldability is maintained. Set individually. Here, the welding condition is a condition parameter that influences the welding result, that is, the welding quality as the weldability and the construction margin, while the groove wall detectability means that the groove walls Wnb and Wsb can be quickly detected. And it is the ability to detect reliably.

That is, the welding conditions and thresholds for one groove wall Wnb and the other groove wall Wsb are individually set for each groove wall Wnb and Wsb in order to maintain excellent welding quality and improve efficiency. When the welding conditions and the threshold value are preferably set, the follow-up welding becomes possible, and the welding quality is ensured even in the welding by a beginner or the automated welding.

Welding conditions for one groove wall Wnb and the other groove wall Wsb include the rotation angle α of the electrode 11 having the electrode tip 11b, the magnitude of the welding current, the arc voltage, and the feeding speed of the welding wire 12. , The stop time of the electrode 11 and the like are included as parameters.
In order to make the welding conditions different from each other in one groove wall Wnb and the other groove wall Wsb, any one of the parameters listed here may be used as a parameter, or all of them may be used as parameters. .. Further, parameters other than the parameters listed here may be used.

As described above, the rotation angle α of the electrode 11 may be set to 90 ° as long as the welding wire 12 can be adjusted to the position of the arc Ar and supplied.

The welding current is such that when one workpiece Wn and the other workpiece Ws are dissimilar metals to each other and the groove angles of the groove walls Wnb and Wsb are the same as in this embodiment, one groove is used. The current value is increased on the hard-to-melt side (in this case, the other groove wall Wsb side) of the wall Wnb and the other groove wall Wsb to increase heat input.
At this time, even if the arc voltage is increased or the welding current value is decreased on the easily meltable side (in this case, the one groove wall Wnb side) of one groove wall Wnb and the other groove wall Wsb. Good. However, when lowering the welding current value, it is necessary to lower the wire feeding speed so that the heat input to one groove wall Wnb and the other groove wall Wsb is not reduced. Further, an arc voltage proportional to this is used to adjust the length of the arc Ar.

The wire feeding speed is any of the cases where one object to be welded Wn and the other object to be welded Ws are different metals from each other and the groove angles of the groove walls Wnb and Wsb are the same as in this embodiment. When the groove walls Wnb and Wsb are set to be equal and the groove angles of the groove walls Wnb and Wsb are different, the shape of the side edge of the weld bead is on one groove wall Wnb side and the other groove wall Wsb side. In addition to setting them differently so that they are the same, adjust the welding current and arc voltage.
If one object to be welded and the other object to be welded are the same type of metal and the groove angles of the groove walls are different, only the wire feeding speed is adjusted.

Further, the threshold values for one groove wall Wnb and the other groove wall Wsb are such that one work piece Wn and the other work piece Ws are dissimilar metals as in this embodiment, and the groove wall Wnb, When the groove angles of Wsb are the same, the groove walls Wnb and Wsb are set to be the same.
When the threshold values are changed for the groove wall Wnb and Wsb, respectively, when the welding torch 8 advances to the groove wall Wnb, the threshold value set for the groove wall Wnb is selected, and the welding torch 8 is applied to the groove wall Wsb. When the process advances, the threshold value set in the groove wall Wsb is selected.

Therefore, the behavior of the electrode 11 when performing copy welding with respect to the groove Wa between one object to be welded Wn and the other object to be welded Ws, which are dissimilar metals to each other, by the copy welding device 1 having such a configuration. This will be described based on the time chart of FIG.

First, when the welding torch 8 having the electrode 11 whose tip is obliquely cut at an angle θ with respect to the axis is moved along the groove Wa at a predetermined speed to perform the oscillating operation (T1), FIG. 2 (a). And, as shown in FIG. 3A, the electrode tip 11b of the electrode 11 is arranged on the side (left side in the drawing) where the welding torch 8 that is oscillated by the control unit 10 advances.

When the welding torch 8 approaches the groove wall Wnb of the groove Wa in this state, the arc Ar generation position is the electrode tip 11b and the groove as shown by the one-point chain line in FIGS. 2 (a) and 3 (a). The distance h from the bottom Wc turns to the distance h1 between the electrode tip 11b and the groove wall Wnb, that is, the distance from the electrode tip 11b to the groove Wa becomes shorter and is set for one groove wall Wnb. AVC is performed to move the welding torch 8 in a direction away from the groove Wa (upward in this embodiment) based on the welding conditions.

Then, when the welding torch 8 rises due to this AVC and the movement amount reaches the threshold value h2 set in advance for one groove wall Wnb (T2), the welding torch 8 continues to rise due to the AVC. To prevent this, AVC is turned off, and in order to ensure welding quality and to make the bead shape a good shape without swelling, welding is performed in the vicinity of one groove wall Wnb with the welding current value suppressed based on the above welding conditions. The torch 8 is stopped for a predetermined time (T3).
In this embodiment, the welding current value is adopted as the parameter of the welding condition, but this is an example, and an item different from the welding current value may be adopted as the parameter of the welding condition.

When the stop time on one groove wall Wnb side ends, the electrode 11 is inverted around the axis (T4), and the AVC is turned on again while the electrode 11 is inverted around the axis (T4). T4').

From the time when the electrode 11 finishes reversing (T5), the welding torch 8 starts the oscillating operation in the opposite direction as shown by the alternate long and short dash line in FIGS. 2 (b) and 3 (b). (T6) When the welding torch 8 approaches the groove wall Wsb of the groove Wa in this state and the arc Ar reaches the groove wall Wsb, the welding conditions set for the other groove wall Wsb are used. Then, AVC is performed to move the welding torch 8 in a direction away from the groove Wa.

Then, when the welding torch 8 is raised by this AVC and the movement amount reaches a threshold value set in advance for the other groove wall Wsb (T7), the odor AVC is turned off, and the other groove wall Wsb side. Then, unlike the one groove wall Wnb side, the welding torch 8 is stopped for a predetermined time in a state where the welding current value is increased based on the welding conditions (T8).

When the stop time on the other groove wall Wsb side ends, the electrode 11 is inverted around the axis (T9), and the AVC is turned on again while the electrode 11 is inverted around the axis (T9). T9').

The welding torch 8 starts an oscillating operation in the opposite direction from the time when the electrode 11 finishes inversion (T10) (T11), and in this state, welds to one groove wall Wnb of the groove Wa. When the torch 8 approaches again, AVC is performed to move the welding torch 8 in the direction away from the groove Wa based on the welding conditions set for one groove wall Wnb, and thereafter, the same as above is performed. The copying operation is performed at the timing (T12, T13, T14, ...).

As described above, in the copy welding device 1 according to this embodiment, one groove wall Wnb and the other groove wall Wsb of the groove Wa between one work piece Wn and the other work piece Ws are respectively. In the above, since the welding conditions and the threshold of the amount of movement of the electrode 11 by AVC are set individually (the thresholds are the same for the groove walls Wnb and Wsb in this embodiment), one of the welded metals is different from each other. Even if the melting conditions of one groove wall Wnb and the other groove wall Wsb are different, such as the object Wn and the other object to be welded Ws, both groove walls Wnb and Wsb are appropriate. It is possible to perform copy welding at various positions.

Further, according to the copy welding apparatus 1 according to this embodiment, the Ni-based alloy steel and the low-alloy steel can be joined. Therefore, for example, a structure in which Ni-based alloy steels are conventionally joined is changed to a Ni-based structure. The structure can be such that alloy steel and low alloy steel are joined. Therefore, the amount of expensive materials such as Ni-based alloy steel used can be reduced to reduce the cost.

FIG. 5 shows the operation of the electrode 11 when performing copy welding with respect to the groove Wa between one object to be welded Wn and the other object to be welded Ws by the copy welding device 1.
The groove Wa between one object Wn to be welded and the other object Ws to be welded cannot perform reciprocating movement (oscillating operation) of the electrode 11 in the groove width direction by the electrode drive mechanism, that is, a so-called narrow groove. Wa. In the copy welding by the copy welding device 1 to such a narrow groove Wa, only the rotation by the rotation mechanism of the electrode 11 and the reciprocating movement in the direction of approaching and separating from the narrow groove Wa by the electrode drive mechanism (vertical direction in the drawing) are performed. ..

That is, the electrode 11 is rotated from the state indicated by the alternate long and short dash line to the state indicated by the solid line (or the alternate long and short dash line) by the rotation mechanism, and the electrode tip 11b is placed on one groove wall Wnb side (or the other groove wall Wsb side). ), The position where the arc Ar is generated changes from the distance h between the electrode tip 11b and the groove bottom Wc to the distance h1 between the electrode tip 11b and the groove wall Wnb, that is, from the electrode tip 11b to the groove Wa. The distance (arc length) is shortened, and the welding torch 8 is moved in a direction away from the groove Wa based on the welding conditions set for one groove wall Wnb (or the other groove wall Wsb). AVC is performed.

Then, when the welding torch 8 is raised by this AVC and the movement amount reaches the threshold value h2 set in advance for one groove wall Wnb (or the other groove wall Wsb), one groove wall Wnb (Or the other groove wall Wsb) is detected (recognized), and the electrode 11 is inverted around the axis.

Therefore, also in this embodiment, one groove wall Wnb and the other groove wall Wsb of the so-called narrow groove Wa between the one work piece Wn and the other work piece Ws which are dissimilar metals to each other. Even if the melting conditions are different, it is possible to perform copy welding at an appropriate position on any of the groove walls Wnb and Wsb.

FIG. 6 shows the groove walls Wb and Wb of the lateral groove Wa between one object to be welded W and the other object to be welded W by the copying welding device 1, that is, groove walls having a vertical positional relationship with each other. The operation of the electrode 11 when performing follow-up welding to Wb and Wb is shown.

In this embodiment, when the welding torch 8 having the electrode 11 whose tip is obliquely cut at an angle θ with respect to the axis is subjected to the oscillating operation, the electrode tip 11b of the electrode 11 is oscillated by the control unit 10. When the welding torch 8 approaches the groove wall Wb on the upper side of the groove Wa in this state, the position where the arc Ar is generated is the tip of the electrode, as shown by the one-point chain line in FIG. The distance h between the electrode tip 11b and the groove bottom Wc changes to the distance h1 between the electrode tip 11b and the groove wall Wb, that is, the distance (arc length) from the electrode tip 11b to the groove Wa becomes shorter, and the upper side Based on the welding conditions set for the groove wall Wb, AVC is performed to move the welding torch 8 in a direction away from the groove Wa (to the right in this embodiment).

Then, when the movement amount of the welding torch 8 reaches the threshold value h2 set in advance with respect to the upper groove wall Wb, the upper groove wall Wb is detected (recognized) and the electrode 11 is inverted around the axis. .. After that, the welding torch 8 starts oscillating operation in the opposite direction to the previous direction, and when the welding torch 8 approaches the lower groove wall Wb of the groove Wa in this state, the lower groove wall Wb AVC is performed to move the welding torch 8 in a direction away from the groove Wa based on the welding conditions set for, and the amount of movement of the welding torch 8 is set in advance with respect to the lower groove wall Wb. When the threshold is reached, the lower groove wall Wb is detected (recognized), and the electrode 11 is inverted around the axis.

Therefore, in this embodiment, like the upper groove wall Wb and the lower groove wall Wb in the lateral groove Wa between the objects W and W, the molten metal hangs down (melts) due to the influence of gravity. Even if the situation) is different, it is possible to perform follow-up welding at an appropriate position on any of the groove walls Wb and Wb.

FIG. 7 shows the case where the copy welding device 1 performs copy welding on a groove Wa in which the angles of the groove walls Wnb and Wsb between one object Wn and the other object Ws are different from each other. The operation of the electrode 11 of the above is shown.

In this embodiment, when the welding torch 8 having the electrode 11 whose tip is diagonally cut at an angle θ with respect to the axial center is subjected to the oscillating operation, the electrode tip 11b of the electrode 11 is controlled as shown by the solid line in FIG. The welding torch 8 oscillating by the portion 10 is arranged on the advancing side (left side in the drawing), and when the welding torch 8 approaches one groove wall Wnb of the groove Wa in this state, as shown by a single point chain line in FIG. , The position where the arc Ar is generated changes from the distance h between the electrode tip 11b and the groove bottom Wc to the distance h1 between the electrode tip 11b and the groove wall Wnb, that is, the distance from the electrode tip 11b to the groove Wa (arc). The length) becomes shorter, and AVC is performed to move the welding torch 8 in the direction away from the groove Wa (upward in this embodiment) based on the welding conditions set for one groove wall Wnb. ..

Then, when the movement amount of the welding torch 8 reaches the threshold value h2 set in advance for the one groove wall Wnb, the one groove wall Wnb is detected (recognized) and the electrode 11 is inverted around the axis. .. After that, the welding torch 8 starts the oscillating operation in the opposite direction to the previous one, and in this state, the welding torch is applied to the other groove wall Wsb whose groove angle is different from that of one groove wall Wnb of the groove Wa. When 8 approaches, as shown by the two-point chain line in FIG. 7, the position where the arc Ar is generated changes from the distance h between the electrode tip 11b and the groove bottom Wc to the distance h1 between the electrode tip 11b and the groove wall Wsb. , AVC is performed to move the welding torch 8 in the direction away from the groove Wa based on the welding conditions set for the other groove wall Wsb, and the amount of movement of the welding torch 8 is previously set to the other groove wall. When the threshold h2 set for Wsb is reached, the other groove wall Wsb is detected (recognized), and the electrode 11 is inverted around the axis.

Therefore, in this embodiment, even if the angles of the groove walls Wnb and Wsb between one work piece Wn and the other work piece Ws are different from each other (the melting state is different). , Both groove walls Wnb and Wsb can be lied welded at appropriate positions.

In the above-described embodiment, the case where the welding apparatus and welding method according to the present invention are used for butt welding has been described as an example, but the present invention is not limited to this, and for example, as shown in FIG. It can also be used for fillet welding.

FIG. 8 shows the operation of the electrode 11 when one object to be welded Wz and the other object to be welded Wx are joined by fillet welding having a large leg length by the copy welding device 1. In this embodiment, the groove-shaped welded portion is the inside corner portion Wd. The groove wall is a surface of one object to be welded Wz and the other object to be welded Wx located on the Wd side of each inside corner.

In this embodiment, when the electrode 11 whose tip is obliquely cut at an angle θ with respect to the axial center is subjected to the oscillating operation, the electrode tip 11b of the electrode 11 is oscillated as shown by the solid line in FIG. 8 (a). The electrode 11 is arranged on the side where the electrode 11 advances (upper left side in the drawing), and in this state, the electrode 11 approaches one of the objects to be welded Wz corresponding to the groove wall of the inside corner Wd, and the position where the arc Ar is generated is the electrode tip 11b. When the distance h between the electrode tip 11b and the other object to be welded Wx is changed to the distance h1 between the electrode tip 11b and one object to be welded Wz, as shown by the two-point chain line in FIG. The distance to the object to be welded Wz is shortened, and the electrode 11 is moved in the direction away from the inside corner Wd (in the direction of the arrow in the figure) based on the welding conditions set for one object to be welded Wz. Is done.

Then, when the movement amount of the electrode 11 reaches a threshold value set in advance for one object to be welded Wz, one object to be welded Wz is detected (recognized) and the electrode 11 is inverted around the axis. After that, as shown by the solid line in FIG. 8B, the electrode 11 starts the oscillating operation in the opposite direction (lower right direction in the drawing), and in this state, on the groove wall of the inside corner Wd. When the electrode 11 approaches the corresponding other object to be welded Wx, the electrode 11 is inserted based on the welding conditions set for the other object to be welded Wx, as shown by the two-point chain line in FIG. 8 (b). AVC is performed to move the electrode 11 in a direction away from the corner Wd (in the direction of the arrow in the figure), and when the amount of movement of the electrode 11 reaches a threshold set in advance for the other work to be welded Wx, the other work to be welded Wx Is detected (recognized), and the electrode 11 is inverted around the axis.

Therefore, in this embodiment, even if one object to be welded Wz and the other object to be welded Wx are joined by fillet welding having a large leg length, both objects to be welded Wz and Wx are in appropriate positions. It is possible to perform fillet welding.

Here, when one object to be welded Wz and the other object to be welded Wx are joined by fillet welding having a small leg length by the copy welding device 1, the electrode 11 is shown by a two-point chain line as shown in FIG. When the electrode tip 11b is rotated from the state to the state shown by the solid line (or one-point chain line) and the electrode tip 11b is placed on one welded object Wz side (or the other welded object Wx side), the arc Ar generation position is the electrode tip end. The distance h between 11b and the other work piece Wx turns to the distance h1 between the electrode tip 11b and one work piece Wz, that is, the distance from the electrode tip 11b to one work piece Wz (arc length). Is shortened, and AVC is performed in which the electrode 11 is moved in a direction away from the inside corner Wd based on the welding conditions set for one work piece Wz (or the other work piece Wx).

Then, when the electrode 11 is raised by this AVC and the movement amount reaches a threshold value set in advance for one work piece Wz (or the other work piece Wx), one work piece Wz is detected. (Recognize) and invert the electrode 11 around the axis.

Therefore, in this embodiment, even if one object to be welded Wz and the other object to be welded Wx are joined by fillet welding with a small leg length, both objects to be welded Wz and Wx are in appropriate positions. It is possible to perform fillet welding.

According to the copy welding device 1 according to the embodiment of FIGS. 8 and 9 described above, in fillet welding, the melting state in the groove wall of one work piece and the melting state in the groove wall of the other work piece are determined. Even if they are different from each other, it is possible to perform fillet welding at an appropriate position.

The configuration of the welding apparatus and welding method according to the present invention is not limited to the above-described embodiment, and can be variously modified without departing from the spirit of the invention.
Further, the welding posture to which the welding device and the welding method according to the present invention are applied is not only the groove copying welding in the downward posture and the lateral posture described above, but also the groove copying welding in the vertical posture and the upward posture. Is also applicable, for example, groove copying welding in all postures in which groove copying welding is performed over the entire circumference of the pipe, and grooves in which one groove wall and the other groove wall of the groove-shaped welded portion form a vertical positional relationship. It can also be applied to groove copying welding in all postures (AWS: 6G posture) in which groove copying welding is performed over the entire circumference of an inclined pipe including each wall portion.

In each of the above embodiments, the case where one object to be welded Wn and the other object to be welded Ws are Ni-based alloy steels and SUSs of different types are shown, but the type of metal used for the object to be welded. Needless to say, is not limited to these.

1 Copy welding equipment (welding equipment)
5 Elevating part (electrode drive mechanism)
7 Slider (electrode drive mechanism)
10 Control units 11, 11A Electrodes (non-consumable electrodes)
11b Electrode tip h2 Threshold W Welded object Wa Groove (grooved weld)
Wb groove wall (groove wall)
Wc groove bottom (groove bottom)
Wd inside corner (grooved weld)
Wn One of the objects to be welded (Ni-based alloy steel)
Wnb One groove wall (groove wall)
Ws The other object to be welded (SUS)
Wsb The other groove wall (groove wall)
Wx One object to be welded Wz The other object to be welded

Claims (7)

A rod-shaped non-consumable electrode with an obliquely cut electrode tip,
The non-consumable electrode is reciprocated in a direction crossing the groove-shaped welded portion between one object to be welded and the other object to be welded to each other by welding, and the non-consumable electrode is reciprocated along the longitudinal direction. An electrode drive mechanism that approaches and separates the groove-shaped welded portion,
A rotation mechanism that rotates the non-consumable electrode around the axis,
A control unit that controls the rotation mechanism so as to arrange the electrode tip on the traveling side in the reciprocating movement of the non-consumable electrode in the direction across the groove-shaped welded portion by the electrode drive mechanism, and performs AVC of the non-consumable electrode. With
In the control unit, the non-consumable electrode moving in a direction crossing the groove-shaped welded portion is brought close to each of one groove wall side and the other groove wall side of the groove-shaped welded portion by the AVC. The welding conditions of one groove wall and the other groove wall for moving the non-consumable electrode in a direction away from the groove-shaped welded portion along the longitudinal direction of the non-consumable electrode and the amount of movement of the non-consumable electrode A welding device in which a threshold value for each of the one groove wall and the other groove wall is set, which causes the non-consumable electrode to perform an operation toward the groove wall in the opposite direction to the previous direction. The welding apparatus according to claim 1, wherein the one object to be welded and the other object to be welded are metals of different types. When the non-consumable electrode cannot be reciprocated in the groove-shaped weld in the direction across the groove-shaped weld by the electrode drive mechanism, the non-consumable electrode is rotated by the rotation mechanism and the electrode is driven. The welding apparatus according to claim 1 or 2, wherein only the reciprocating movement of the mechanism so as to approach and separate the groove-shaped welded portion in the direction along the longitudinal direction of the non-consumable electrode is performed. Claims 1 to 3 that one groove wall and the other groove wall of the groove-shaped welded portion have a vertical positional relationship with each other or include a groove wall portion having a vertical positional relationship with each other. The welding apparatus according to any one of the sections. The welding apparatus according to claim 1 or 2, wherein the angles of one groove wall and the other groove wall of the groove-shaped welded portion with respect to the groove bottom are different from each other. The claim that one object to be welded and the other object to be welded are joined to each other by fillet welding, and the groove-shaped weld is an inside corner formed between the one object to be welded and the other object to be welded. The welding apparatus according to any one of 1 to 3. A non-consumable electrode having a rod-shaped electrode tip cut diagonally is reciprocated in a direction crossing a groove-shaped welded portion between one workpiece and the other workpiece to be joined to each other by welding, and the non-consumable electrode is elongated. When moving back and forth along the direction to approach and separate the groove-shaped welded portion,
The electrode tip is arranged on the advancing side in the reciprocating movement of the non-consumable electrode in the direction across the groove-shaped welded portion, and the non-consumable electrode is AVCed to move in the direction across the groove-shaped welded portion. When the consumable electrode approaches one groove wall of the groove-shaped welded portion, the non-consumable electrode is placed along the longitudinal direction of the non-consumable electrode by the AVC based on the welding conditions set for the one groove wall. The non-consumable electrode is moved in a direction away from the groove-shaped welded portion, and when the amount of movement of the non-consumable electrode reaches a threshold set for the one groove wall, the non-consumable electrode is moved toward the other groove wall. At the stage when the non-consumable electrode moving in the direction across the groove-shaped welded portion approaches the other groove wall of the groove-shaped welded portion, the one groove wall is referred to with respect to the other groove wall. Based on the welding conditions set separately, the non-consumable electrode is moved by the AVC in a direction away from the groove-shaped welded portion along the longitudinal direction of the non-consumable electrode, and the amount of movement of the non-consumable electrode is the other. A welding method in which the non-consumable electrode is made to perform an operation toward the one groove wall when the groove wall reaches a threshold value set separately from the one groove wall.

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