JP2795429B2 - Oscillate welding method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an oscillating welding method in which a welding electrode is periodically oscillated in a groove in a groove to perform welding.

[0002]

2. Description of the Related Art When performing butt welding or fillet welding by arc welding, an oscillating method is generally employed in which a welding electrode is periodically oscillated in order to form a flat weld metal and reduce internal defects. Welding methods are being adopted. A conventional oscillating welding method is disclosed in
As disclosed in JP-A-283462, the swing width is determined with the position of the welding electrode when the groove wall is detected as the final end, and the welding torch 54 is swung with this swing width. The detection of the groove wall is performed in the consumable electrode type and the non-consumable electrode type as follows.

That is, in the case of the consumable electrode type arc welding, as shown in FIG. 7, the protruding length of the welding electrode 53 is reduced as the welding electrode 53 approaches the groove wall 51a of the base material 51. Utilizing that the welding current rises due to
The groove wall 51a is detected by determining whether or not the welding current has exceeded a predetermined value. On the other hand, in the case of the non-consumable electrode type arc welding, as shown in FIG. 8, when the arc length of the welding electrode 53 is controlled to be kept constant, as the welding electrode 53 approaches the groove wall 51a. Utilizing the rise, it is determined whether or not the height position of the welding electrode 53 has reached or exceeded a predetermined value, thereby detecting the groove wall 51a.

Accordingly, in the conventional oscillating welding method, as shown in FIG. 9, the inner side of the groove wall 51a rather than the open front end 51b, which is the front end of the groove wall 51a, is set as the final end of the swing width. After the welding electrode 53 is stopped at this final end for a predetermined time, the welding is performed while the welding electrode 53 is rocked by the oscillating locus 52 that moves in the other direction.

[0005]

However, in the conventional oscillating welding method described above, as shown in FIGS. 7 and 8, the welding electrode 53 is attached to the last end of the swing width located inside the groove wall 51a. Since welding is performed while stopping for a predetermined time, the distance from the welding electrode 53 located at the final end to the open front end portion 51b becomes large, and it becomes difficult for the arc to reach the open front end portion 51b. It is easy to generate defects such as poor fusion without obtaining melting. In particular, the occurrence of this defect becomes remarkable when the height of the weld metal 55 is large or when the groove angle is large, because the distance from the welding electrode 53 to the open tip portion 51b increases.

Therefore, in arc welding of the non-consumable electrode type, as disclosed in Japanese Patent Application Laid-Open No. 54-35186, the feeding speed of the filler material and the welding current are changed at both ends of the oscillate of the welding electrode 53. A method of stabilizing the welding by causing the welding has been proposed. However, even in this case,
If the welding electrode 53 and the open distal end 51b are far apart, heat input to the open distal end will be insufficient, making welding instable and insufficient penetration.

Therefore, in the present invention, the weld metal 55
It is an object of the present invention to provide an oscillating welding method capable of always ensuring sufficient penetration and stabilizing welding regardless of the height of a groove or the size of a groove angle.

[0008]

In order to solve the above-mentioned object, the present invention provides an oscillating welding method in which a welding electrode is set in a groove by using a detection position of a pair of groove walls as a final end of a swing width. The welding is performed while repeatedly rocking in the width direction, and has the following features.

That is, the oscillating welding method of claim 1 is
The welding electrode is moved in one width direction, the groove wall is detected, and the welding electrode is moved in the center direction of the groove from the detection position of the groove wall, and a predetermined position is formed above the opening end of the groove wall. After the operation is stopped, the welding electrode is moved in the other width direction to detect a groove wall, and the welding electrode is moved from the detection position of the groove wall toward the groove center to open the groove. It is characterized in that it is stopped for a predetermined time above the open end of the front wall.

[0010] The oscillating welding method according to claim 2 is characterized in that:
The oscillating welding method according to claim 1 is applied to a non-consumable electrode type arc welding apparatus, wherein an operation for reducing a filler material supply amount and a welding current are increased while the welding electrode is stopped for a predetermined time. It is characterized in that at least one of the operations to be performed is performed. Further, the oscillating welding method according to claim 3 is characterized in that the oscillating welding method according to claim 1 or 2 obtains the movement amount of each of the grooves toward the center of the groove from the height of the weld metal and the groove angle.

[0011]

According to the first to third aspects of the present invention, the welding is performed while the welding electrode is stopped for a predetermined time above the open front end, so that the height of the weld metal and the angle of the groove can be reduced. Irrespective of this, the distance between the welding electrode and the open tip can always be kept to the shortest distance. As a result, sufficient penetration can be ensured and welding can be stabilized.

Further, according to the second aspect of the invention, the molten state of the filler material and the penetration into the material to be welded can be made appropriate at any position within the groove, so that the welding is further stabilized. It is possible to make it. According to the third aspect of the present invention, the amount of movement of each groove toward the center is obtained from the height of the weld metal and the angle of the groove, so that the welding electrode can be reliably positioned above the open end of the groove wall. And the welding can be further stabilized.

[0013]

【Example】

Embodiment 1 One embodiment of the present invention will be described with reference to FIGS. As shown in FIG. 1, the oscillating welding method according to the present embodiment employs a non-consumable electrode type arc in which welding is performed while periodically swinging the welding electrode 5 within a groove between a pair of groove walls 4a. It is implemented in a welding device.

As shown in FIG. 2, the above-described arc welding apparatus has a welding torch 1 which is moved in a vertical direction and a horizontal direction by a vertical shaft drive unit 20 and a left and right shaft drive unit 17 comprising a screw shaft and a screw nut. doing. The welding torch 1 holds a welding electrode 5 made of tungsten or the like.
Are connected at one end. The other end of the constant current power supply 30 is connected to the base material 4 to be welded by the arc from the welding electrode 5, and the welding voltage between the base material 4 and the welding electrode 5 is detected by the welding voltage comparison unit 21. It is supposed to be.

The welding voltage comparing section 21 is connected to a welding voltage setting section 23 for outputting a comparison voltage. The welding voltage comparison unit 21 outputs a difference signal indicating a difference voltage between the welding voltage between the base material 4 and the welding electrode 5 and the comparison voltage to the vertical axis control unit 22. The control unit 22 controls the vertical axis drive motor 18 to move the welding electrode 5 up and down via the welding torch 1 so that the difference signal has a predetermined value.

An up / down axis pulse encoder 19 for outputting a pulse signal at every predetermined rotation angle is connected to the up / down axis drive motor 18. Vertical axis pulse encoder 1
Reference numeral 9 is connected to an upper / lower axis pulse counting section 24, and the upper / lower axis pulse counting section 24 counts a pulse signal from the upper / lower axis pulse encoder 19. And
The vertical axis pulse counting unit 24 is connected to the groove wall detection determining unit 25, and outputs the count value of the pulse signal to the groove wall detection determining unit 25 as the height position of the welding electrode 5. I have. The groove wall detection / judgment unit 25 receives an inversion height setting value from the inversion height setting unit 41, and the groove wall detection / judgment unit 25 calculates the count value and the inversion height setting value. When the count value becomes equal to the inversion height set value, an arrival signal is output assuming that the welding electrode 5 has reached the vicinity of the groove wall.

The above arrival signal is calculated by a left-right axis movement amount calculation unit 1
3 is input. The right and left axis pulse counting unit 11 and the left and right axis pulse counting unit 11 are connected to the left and right axis pulse calculating unit 13.
The left and right axis pulse encoders 16 are connected. The left and right axis pulse encoder 16 is connected to the left and right axis drive motor 15 for driving the above left and right axis drive unit 17, and outputs a pulse signal to the left and right axis pulse counting unit 11 at each predetermined rotation angle of the left and right axis drive motor 15. Output. Then, the left and right axis pulse counting unit 11 outputs the counted value of the pulse signal to the groove wall detection determination unit 25 as the left and right position of the welding electrode 5.

On the other hand, the movement amount calculator 14 outputs a movement amount calculation value L indicating the horizontal distance from the welding electrode 5 to the open tip 4b to the left and right axis movement amount calculator 13. I have. As shown in FIG. 4, the movement amount calculation value L is a distance h from the position where the axis of the welding electrode 5 intersects the groove wall 4a to the bottom surface of the base material 4 and a groove angle θ. × ta
It is calculated by substituting into n (θ / 2), where h is a value set from the height setting part 46 and θ is a value set from the groove opening degree setting part 47. In this embodiment,
Although the peak height is set in advance, it can be obtained by calculation from the wire feed amount and the welding speed. And
As shown in FIG. 2, the left / right axis movement amount calculation unit 13 calculates the difference between the value obtained by subtracting the movement amount calculation value L from the count value at the time of input of the arrival signal and the count value from the left / right axis pulse counting unit 11. The correction value shown is output to the left and right axis control unit 12. Further, the left-right axis control unit 12 stops moving the welding electrode 5 in the left-right direction at the time of inputting the correction value, and then moves the welding electrode 5 toward the center of the groove by a moving amount according to the correction value. And the welding electrode 5 is opened at the tip 4b.
, And after the elapse of the stop time specified by the left / right axis stop control unit 43, the welding electrode 5 is moved toward the other end.

As shown in FIG. 3, the left-right axis movement amount calculator 13 is also connected to a both-ends stop detector 34.
When it is confirmed that the movement of the welding electrode 5 by the correction value has been completed, a correction completion signal is output to the both-ends stop detector 34 until the stop time elapses. The both-ends stop detecting section 34 is connected to a welding current setting switching section 39 including a relay having an a contact and a b contact and a filler material feeding speed switching section 40.・ 40 is turned on.

The above welding current setting switching section 39 has one end of the a contact and the b contact connected to the constant current power supply 30, while the other end of the a contact and the b contact has the welding current setting section 36 at both ends. They are connected to the current setting unit 35, respectively. Then, the welding current setting switch 39 is turned on (O
In the state N), the output current of the constant current power supply 30 is set to a current value suitable for welding the open front end portion 4b by connecting the welding current setting section 36 at both ends and the constant current power supply 30 to the connected state. On the other hand, when the welding current setting unit 35 and the constant current power supply 30 are connected to each other in the OFF state, the output current of the constant current power supply 30 is adjusted to a current value suitable for welding the inside of the groove. Is set to.

The filler feed speed switching unit 40 has one end of the contact a and the contact b connected to the filler feed speed control unit 33, and the other end of the contact a and the contact b. Both ends are connected to a filler material supply speed setting unit 38 and a filler material supply speed setting unit 37, respectively. The above-mentioned filler material feed speed control unit 33 is connected to the filler material feed motor 32 that feeds the filler material 3, and controls the feed speed of the filler material 3. . And, the filler material feeding speed switching unit 40
In the ON state, the feed speed of the filler material 3 is opened by connecting the filler feed speed setting unit 38 at both ends and the filler feed speed control unit 33 in a connected state. Part 4
While the speed is set to be suitable for the welding of b, in the OFF (OFF) state, the filler material feeding speed setting part 37 and the filler material feeding speed control part 33 are connected. Thereby, the feeding speed of the filler material 3 is set to a speed suitable for welding the inside of the groove.

In the above configuration, an oscillating welding method will be described through the operation of the arc welding apparatus.

As shown in FIG. 2, when a constant welding current is supplied from the constant current power supply 30 to the welding electrode 5 and welding to the base material 4 is started, the welding electrode 5 is moved right and left by the left and right shaft driving unit 17. Will be moved in that direction. As shown in FIG. 4, when the welding voltage between the welding electrode 5 and the base material 4 increases as the welding electrode 5 approaches the groove wall 4a, the welding voltage is detected as shown in FIG. The welding voltage comparison unit 21 outputs a difference signal from the comparison voltage corresponding to the rise of the welding voltage to the vertical axis control unit 22,
Drives the vertical axis drive motor 18 to raise the welding electrode 5 so that the difference signal has a predetermined value.

The amount of rise of the welding electrode 5 is grasped by counting pulse signals from an upper and lower axis pulse encoder 19 connected to an upper and lower axis drive motor 18 by an upper and lower axis pulse counting unit 24. The count value of the vertical axis pulse counting unit 24 is determined as the height position of the welding electrode 5 by the groove wall detection determining unit 25.
And the groove wall detection determination unit 25 compares the value with the inverted height setting value from the inverted height setting unit 41. When the count value matches the inversion height set value, the groove wall detection determination unit 25 outputs a reaching signal to the left-right axis movement amount calculation unit 13 assuming that the welding electrode 5 has reached the vicinity of the groove wall. Will do.

Upon recognizing that the welding electrode 5 has reached the vicinity of the groove wall by inputting the arrival signal, the left-right axis movement amount calculation unit 13 calculates the movement amount calculation unit 14 from the count value from the left-right axis pulse counting unit 11. The difference between the value obtained by subtracting the movement amount calculation value L calculated based on the preset height h and the groove angle θ, and the count value from the left and right axis pulse counting unit 11 is calculated. Is output to the left and right axis control unit 12 as a correction value. Then, after stopping the movement of the welding electrode 5 in the left-right direction by inputting the correction value, the left-right axis control unit 12 moves the welding electrode 5 toward the groove center by a moving amount according to the correction value. , The welding electrode 5 is positioned above the open tip 4b. Thereafter, the welding electrode 5 is moved in the other end direction after the elapse of the stop time designated by the left / right axis stop control unit 43, and the above operation is repeated, whereby the oscillation locus 44 shown in FIG. You will move with it.

When the welding electrode 5 is stopped and moved, the left and right axis movement amount calculating section 13 includes a welding current setting switching section 39 and a filler material feeding speed switching section 40 as shown in FIG. Is switched between an ON (ON) state and an OFF (OFF) state. When the welding electrode 5 is stopped, the welding current setting unit 36 at both ends and the constant current power supply 30 are connected to each other, so that the output current of the constant current power supply 30 becomes a current suitable for welding the open tip 4b. The feed speed of the filler 3 is increased by setting the filler feed speed setting unit 38 at both ends and the filler feed speed control unit 33 to a connected state. The speed is set to a speed suitable for welding the tip 4b. On the other hand, when the welding electrode 5 is moved, the welding current setting unit 35 and the constant current power supply 30 are connected, so that the output current of the constant current power supply 30 becomes a current value suitable for welding inside the groove. At the same time, the filler material feeding speed setting unit 3
The connection speed of the filler metal 7 and the filler material feed speed controller 33 allows the feed speed of the filler material 3 to be set to a speed suitable for welding the inside of the groove.

[Embodiment 2] Another embodiment of the present invention will be described with reference to FIG. The same members as those in the first embodiment are denoted by the same reference numerals, and description thereof will be omitted.

As shown in FIG. 5, the oscillating welding method according to the present embodiment is performed in a consumable electrode type arc welding apparatus. This arc welding equipment
Similarly to the above-described first embodiment, a left and right axis drive unit 17 and a left and right axis drive motor 15 for moving the welding electrode 5 in the left and right direction are provided, and the left and right axis control unit 12, the left and right axis stop control unit 43, Left and right axis pulse counting unit 11, left and right axis movement amount calculation unit 1
3, and the movement amount calculation unit 14, after stopping the movement of the welding electrode 5 in the left-right direction,
Is moved toward the groove center by a moving amount corresponding to the correction value, so that the welding electrode 5 is positioned above the open front end portion 4b for a predetermined time.

The above-mentioned welding electrode 5 can change the protruding length of the welding electrode 5.
A constant welding voltage is applied from the constant voltage power supply 28. A current detection unit 45 for detecting a welding current is connected to the base material 4 to be welded by the welding electrode 5, and the current detection unit 45 outputs a welding current value to the groove wall detection determination unit 25. It has become. Then, the groove wall detection determination unit 25 compares the reverse current setting value from the reverse current setting unit 48 with the welding current value, and when the welding current value becomes equal to the reverse current setting value, the welding electrode 5 is turned off. The arrival signal is output to the left / right axis movement amount calculation unit 13 assuming that the vehicle has reached the vicinity of the groove wall. The following configuration is the same as in the first embodiment, and a description thereof will not be repeated.

In the above configuration, when the length of the welding electrode 5 protruding becomes shorter as the welding electrode 5 approaches the groove wall 4a, the welding current generated by the constant voltage power supply 28 increases. This welding current is detected by the current detection unit 45, and the welding current value is output to the groove wall detection determination unit 25. The welding current value input to the groove wall detection determining unit 25 is compared with the reverse current setting value from the reverse current setting unit 48, and when the welding current value becomes equal to the reverse current setting value, the welding electrode is detected. The arrival signal is output to the left / right axis movement amount calculation unit 13 assuming that 5 has reached the vicinity of the groove wall. Thereafter, the movement of the welding electrode 5 in the left-right direction is stopped by the same operation as that of the above-described first embodiment, and then the welding electrode 5 is moved toward the center of the groove to open the tip 4.
b. Then, after the elapse of the stop time designated by the left / right axis stop control unit 43, the welding electrode 5 is moved in the other end direction, and the welding electrode 5 is moved along the oscillating locus 44 shown in FIG.
Will move.

As described above, according to the oscillating welding methods of the first and second embodiments, as shown in FIG. 1, the detection positions of the pair of groove walls 4a are used as the final ends of the swing width to set the welding electrode 5 Is welded by periodically swinging in the width direction in the groove, and the welding electrode 5 is moved in one width direction (for example, rightward) to detect one groove wall 4a. At the time, the first operation of moving the welding electrode 5 from the detection position of the groove wall 4a toward the center of the groove and stopping it for a predetermined time above the open front end 4b of the groove wall 4a, and the first operation After the end, the welding electrode 5 is moved in the other width direction, and when the other groove wall 4a is detected, the welding electrode 5 is moved toward the groove center from the detection position of the groove wall 4a. Groove wall 4
The second operation for stopping for a predetermined time above the open front end portion 4b of a is an operation for one cycle.

Since the welding is performed while the welding electrode 5 is stopped above the open end portion 4b for a predetermined time, the welding electrode 5 is irrespective of the height of the weld metal 2 and the size of the groove angle. It is possible to always make the distance between 5 and the open tip 4b the shortest distance. As a result, it is possible to secure sufficient penetration and stabilize welding. Further, in the oscillating welding in which the welding electrode 5 approaches the groove while approaching the groove wall 4a, particularly when the welding current is large in the upper layer of the groove, as shown in FIG.
The groove shoulder 4c may melt and the oscillation width may not be stable. In this embodiment, however, the groove shoulder 4c is unlikely to melt, thereby stabilizing the groove copying operation. Is available.

The oscillating welding method of the present embodiment
When applied to a non-consumable electrode-type arc welding apparatus, at least one of an operation of decreasing the amount of filler material supplied and an operation of increasing the welding current while the welding electrode 5 is stopped for a predetermined period of time. It is supposed to do. Thereby, the filler material 3
It is possible to stabilize the welding by setting the molten state of the open tip portion 51b and the molten state of the open tip portion 51b to be appropriate.

[0034]

According to the first aspect of the present invention, as described above, the welding electrode is moved in one width direction, the groove wall is detected, and the welding electrode is moved from the detection position of the groove wall toward the groove center. To stop for a predetermined time above the open tip of the groove wall, and after the operation is completed, move the welding electrode in the other width direction, detect the groove wall, and detect the groove wall. The welding electrode is moved toward the center of the groove from the detection position and stopped for a predetermined time above the open front end of the groove wall.

Accordingly, the welding is performed while the welding electrode is stopped for a predetermined time above the open front end portion, so that regardless of the height of the weld metal or the size of the groove angle,
The distance between the welding electrode and the open tip can be always kept to the shortest distance. As a result, there is an effect that sufficient penetration can be ensured and welding can be stabilized.

According to a second aspect of the present invention, as described above, the oscillating welding method of the first aspect is applied to a non-consumable electrode-type arc welding apparatus. The configuration is such that at least one of an operation of decreasing the filler material supply amount and an operation of increasing the welding current is performed.

Thus, in addition to the effect of the first aspect, since the molten state of the filler material can be made appropriate at any position in the groove, the welding can be further stabilized. This has the effect. Furthermore, in the case of oscillating welding that imitates a groove while bringing the welding electrode close to the groove wall, especially when the welding current is large in the upper layer of the groove, the shoulder of the groove may melt and the oscillate width may not be stable. However, there is an effect that the groove shoulder is hardly melted and the groove copying operation can be further stabilized.

According to a third aspect of the present invention, as described above, the oscillating welding method according to the first or second aspect is such that the amount of movement toward the center of each groove is obtained from the height of the weld metal and the angle of the groove. Therefore, there is an effect that it is possible to reliably move the welding electrode above the open front end of the groove wall and to further stabilize the welding.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram showing an oscillating locus of an oscillating welding method of the present invention.

FIG. 2 is a block diagram of a main part of a non-consumable electrode type arc welding apparatus.

FIG. 3 is a main block diagram of a non-consumable electrode type arc welding apparatus.

FIG. 4 is an explanatory diagram showing a stop position of a welding electrode.

FIG. 5 is a main block diagram of the consumable electrode type arc welding apparatus.

FIG. 6 is an explanatory diagram showing a position of a shoulder portion of a groove.

FIG. 7 shows a conventional example, and is an explanatory view showing a moving state of a welding electrode in a consumable electrode type arc welding apparatus.

FIG. 8 shows a conventional example, and is an explanatory view showing a moving state of a welding electrode in a non-consumable electrode type arc welding apparatus.

FIG. 9 is an explanatory diagram showing an oscillating locus of a conventional oscillating welding method.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Welding torch 2 Weld metal 3 Filler 4 Base material 4a Groove wall 4b Open tip 4c Shoulder 5 Welding electrode 11 Left and right axis pulse counting unit 12 Left and right axis control unit 13 Left and right axis movement amount calculation unit 14 Movement amount calculation unit 15 Left and right axis drive motor 16 Left and right axis pulse encoder 17 Left and right axis drive unit 18 Vertical axis drive motor 19 Vertical axis pulse encoder 20 Vertical axis drive unit 21 Weld voltage comparison unit 22 Vertical axis control unit 23 Weld voltage setting unit 24 Vertical axis pulse count Unit 25 groove wall detection judgment unit 28 constant voltage power supply 30 constant current power supply 32 filler metal feeding motor 33 filler material feeding speed control unit 34 both ends stop detection unit 35 welding current setting unit 36 both ends welding current setting unit 37 melting Filling material feed speed setting unit 38 Both ends filler material feeding speed setting unit 39 Welding current setting switching unit 40 Filler material feeding speed switching unit 41 Inversion height setting unit 43 Left / right axis stop control unit 44 Oscillate locus 45 Current detection unit 46 Height setting unit 47 Groove angle setting unit 48 Reverse current setting unit

Continued on the front page (72) Inventor Tetsuo Suga 100-1 Urakawachi, Miyama-ji, Fujisawa-shi, Kanagawa Prefecture Kobe Steel, Ltd. Fujisawa Works (72) Inventor Fusaki Koshiishi 100-1, Urakawachi, Miyama-shi, Fujisawa-shi, Kanagawa Stock Kobe Steel, Ltd. Fujisawa Works (72) Inventor Kazuo Furusato 100-1, Urakawachi, Miyamae, Fujisawa-shi, Kanagawa Prefecture Kobe Works, Ltd. Fujisawa Works (56) References JP-A-55-153681 (JP, A) 53-89846 (JP, A) (58) Fields investigated (Int. Cl. ⁶ , DB name) B23K 9/12 350 B23K 9/022 B23K 9/127 507

Claims (3)

(57) [Claims] 1. An oscillating welding method for performing welding while repeatedly oscillating a welding electrode in a width direction within a groove with a detection position of a pair of groove walls as a final end of a oscillating width, wherein: moved in one width direction, and detects the groove walls, after moving from the detection position of the open destination wall welding electrode groove center direction, said welding electrode over the open distal end of the open destination wall
Is stopped for a predetermined time in the width direction of the groove, and after the operation is completed, the welding electrode is moved in the other width direction to detect a groove wall, and the welding electrode is grooved from the detection position of the groove wall. An oscillating welding method, comprising: moving the welding electrode in the width direction of the groove for a predetermined time above the open end of the groove wall after moving the groove in the center direction. 2. An arc welding apparatus of a non-consumable electrode type, wherein a welding material supply amount is reduced during a predetermined time in a width direction of a groove of the welding electrode. 2. The method according to claim 1, wherein at least one of an operation for increasing the welding current and an operation for increasing the welding current is performed. 3. The oscillating welding method according to claim 1, wherein the amount of movement of each groove toward the center is determined from the height of the weld metal and the groove angle.