JP2994805B2 - Narrow groove 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 a narrow groove welding method in GMA (gas shield consumable electrode arc) welding.

[0002]

In general, the narrow groove MIG or MAG welding method, as shown in FIG. 6, when even slightly, preform 03,0
There is a risk of insufficient penetration of the weld metal 010,010' to the wall 04 of the groove 02 between the 3, In order to prevent this, create a weld metal 011 and 011' of the shape shown in FIG. 7, the opening It is necessary to sufficiently melt the bottom corner of the tip 02.

[0003] In order to prevent the insufficient penetration 04, many proposals have been made conventionally. For example, Japanese Utility Model Application 56-5
No. 0157, Japanese Utility Model Application No. 56-50949, and Japanese Patent Application No. 56-56
No. 205156, Japanese Patent Application No. 57-57327, Japanese Patent Application No. 5
8-12923 and Japanese Patent Application No. 63-188850.

[0004]

However, in the various welding methods proposed above, in the case of relatively high current welding at the time of downward welding, only the shapes of the weld metals 011 and 011 'shown in FIG. 7 are obtained. In low-current welding such as vertical welding, upward welding, and all-position welding, the penetration shape becomes like welding metal 010 and 010 ′ shown in FIG. 6 , and insufficient penetration 04 cannot be completely prevented. At present, it is not applied to position welding other than the above-described downward welding.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a narrow groove welding method in which the bottom corner of the groove is stable and has sufficient penetration even in vertical, upward and all-position welding.

[0006]

SUMMARY OF THE INVENTION In order to achieve the above objects, the present invention is directed to a vertical, upward, and all-position welding.
In the gas-shielded consumable electrode arc welding method of the above, a welding torch provided with a power supply tip having a wire feed port is used, and the torch angle θ is set to θ> 0 ° with respect to the welding progress direction
The tip of the wire projecting from the feed tip at the tip of the torch body is tilted with respect to the axis of the welding torch, and the feed tip is rotated so that the tip of the wire moves in the direction opposite to the welding direction. By rotating, a circular arc-shaped weld metal is formed that is concavely curved with respect to the groove bottom surface by the kinetic energy of the scattered droplets of the wire, and the weld metal is laminated.

[0007]

Describing the effect of the present invention using the [action] FIGS.
In FIG. 1, 1 is a weld metal (bead), 2 is a groove, 3
Is a base material. As shown, the groove 2 is a narrow and deep groove. Reference numeral 5 denotes a welding torch main body, in which a wire feeding nozzle 51 is rotatably supported. A power supply tip 52 is attached to the tip of the wire feed nozzle 51 so that the tip of the welding wire 6 is eccentrically projected from the welding torch axis. In the figure, φ is the eccentric angle, and the tip of the welding wire 6 protruding from the power supply tip 52 is inclined at an eccentric angle φ with respect to the axis of the welding torch. FIG.
In, while moving the welding torch to the welding direction (the direction of arrow A in FIG. 2), and while rotating the welding wire 6 to the welding direction in the opposite direction (arrow B direction), the welding as shown in FIG. 7 The metal 1 is laminated one after another. The rotation angle in the direction of arrow B is half a rotation (18
0 °). By rotating the power supply tip 52 in this way and rotating the wire tip in the direction opposite to the welding progress direction A (the direction of arrow B), the arc-shaped weld metal 1 that is curved in a concave shape is formed. The weld metal 1 is laminated. In FIG. 1, the welding torch is inclined at a torch angle θ (described later). Therefore, when the wire feed nozzle 51 is rotated, the power supply tip 52 is also rotated, and the welding wire 6 is rotated.
Can reliably direct the corners of the groove 2 and produce a weld metal 1 free from poor penetration.

FIGS. 2 and 3 show the tilt of the rotary electrode type torch and the rotation of the welding wire. 2, 5 is a welding torch main body, 6 is a welding wire, 51 is a wire feeding nozzle, and 52 is a power supply tip, which is the same as FIG. θ is the torch angle, which is the inclination angle of the torch axis with respect to a reference plane perpendicular to the welding plane. A is a welding progress direction, and B is a rotation direction of the welding wire 6 about the torch axis. FIG. 9A shows a case where the angle θ is a positive torch advance angle (as shown, the torch tip is θ>
If you are inclined so that the 0 °), when the figure (b) the angle θ is 0 ° (i.e., when the perpendicular to the welding torch axis welding direction A), FIG. (C) is This is the case where the angle θ is a negative torch receding angle (when the tip of the torch is inclined in the opposite direction so that θ <0 ° with respect to the welding progress direction A as shown). In this case, the turning direction B of the welding wire is opposite to the welding traveling direction A in each case. FIG. 3 shows vertical welding, in which (1),
(2) and (3) show the torch posture (θ> 0 °, θ = 0)
°, θ <0 °) and the molten metal liquid surface H was viewed in plan.
Shows the relationship between the trajectory of the wire tip and the planar shape of the bead.
ing. FIG. 3A shows a case where the torch advance angle (θ> 0 °).
(2) is vertical (θ = 0 °), (3) is
This is the case where the angle is set back (θ <0 °). First, in FIG.
The case (1) will be described. In this case, as shown in (c)
To weld progression Direction A, in the opposite direction (arrow B direction)
When the torch shaft rotates about half a turn (180 °), the wire
The tip is O1 → O3 → O in (b) with respect to the groove bottom surface S.
2 → O3 → O1 ... repeatedly rotate in an arc shape
You. The point O is a horizontal plane of O1 and O2 (molten metal liquid).
(Plane) H is a projection point. At this time, the scattered drops of the wire 6
Is scattered toward the liquid level H of the molten metal and jumps into the molten metal
No. Therefore, the kinetic energy of the scattered droplet is (b)
As shown in the figure, the molten metal is placed at the back of the groove (left side in the figure).
Acts as a pushing force F. Therefore, as shown in (a)
As shown, the shape of the molten metal (bead) is
On the other hand, it has a circular arc shape that is concavely curved. Like this
Use the kinetic energy of the splattered droplets to create a bead shape
By actively forming such an arc, the bead
The melter is firmly melt-bonded so that there is no gap
And bead is fully melted into the corner of the groove bottom
be able to. If θ> 0 °, as described above,
And good melting results are obtained. Next, place (2) in FIG.
Will be described. In this case, as shown in FIG.
Is vertical (θ = 0 °). The wire tip is (b)
As shown by O1 → O3 → O2 → O3 → O1 ...
Reciprocate linearly. Therefore, the scatter of droplets
The force F of the kinetic energy is represented by the voltage as shown in (a) and (b).
Acts equally on both sides of the card. Therefore, as shown in (a)
The shape of the bead is such that θ> 0 ° shown in (1) (a) of FIG.
It is closer to a straight line than in the case,
Penetration into the corner of the groove bottom is less than when θ> 0 °
Inferior. Next, the case of (3) in FIG. 3 will be described. This place
In this case, as shown in (c), the torch axis moves backward (θ <0).
°). Also, as shown in FIG.
Opposite direction to the case of θ> 0 ° shown in (1) and (b) of FIG.
It becomes a concave arcuate arc, and O1 → O3 → O2 →
O3 → O1... Repeatedly rotate. Accordingly
The force F of the kinetic energy of the scattered droplet of the wire 6 is on the back side of the groove
Acts as a force to move from the front to the front (right side in the figure)
As a result, the shape of the bead is changed as shown in (a).
In this case, the shapes are not easily melt-bonded to each other. Therefore
The melting result is inferior to the case where θ> 0 °. Referring to FIG.
From what has been described above, the present invention relates to FIG.
Then , welding is performed by the method of θ> 0 ° shown in FIG.
I am trying to.

As a result of performing the welding test under various conditions as described above, when the tip of the welding wire 6 is rotated in the same direction as the welding progress direction (the direction of the arrow B ′ in FIG. 2), 6 also had a shape causing insufficient penetration 04 shown in FIG. 6 , and satisfactory welding quality was not obtained. On the other hand, when the tip of the welding wire 6 is rotated in the opposite direction (the direction of arrow B) to the welding progress direction, the torch angle θ and the welding wire 6
It is clear that a good penetration shape close to that of FIG. 7 can be obtained by the combination of the eccentric angles φ. That is, the inclination and welding progress direction of the welding torch and the rotating direction of the wire (arrow B)
Direction or the direction of the arrow B ′), it is clear that there is a large difference in welding quality.

FIG. 4 shows an I-shaped groove having a groove width of 12 mm.
In the case of up to 20 m, the direction B opposite to the welding direction A
FIG. 7 shows the relationship between θ and φ at which a proper penetration shape is obtained when the welding wire 6 is rotated to perform narrow groove welding. The welding posture is a standing posture and an upward posture. From FIG. 4,
It can be seen that when the angle θ, which is the inclination of the torch, is in the negative range, molten metal dripping or poor penetration (gap) occurs at the center of the bead. Further, it is understood that when the angle θ exceeds 15 °, poor penetration occurs at the groove corner. Therefore, when the groove shape is I-shaped and the groove width is 12 to 20 m, the angle θ is set in the range of 0 ° ≦ θ ≦ 15 °.

On the other hand, when the eccentric angle φ of the wire is less than 7 °,
It can be seen that poor penetration occurs at the corners in the groove and the wall surface of the groove. When the eccentric angle φ exceeds 20 °, the frictional resistance of the wire in the power supply tip becomes large, and the wire feeding becomes poor, and the welding becomes unstable. For this reason, the eccentric angle φ is set in the range of 7 ° ≦ φ ≦ 20 °.

If the angle θ and the eccentric angle φ are in the above ranges,
Narrow groove welding of an I-shaped groove that is always stable without insufficient penetration is possible. If the angle θ and the eccentric angle φ are within the above ranges, the present invention can be applied to narrow groove welding of a U-shaped groove and a V-shaped groove, and downward welding is also possible.

FIG. 5 shows the structure of a rotary electrode type welding torch used when carrying out the narrow groove welding method according to the present invention. 5 , 2 is an I-shaped groove, 3 is a base material, 5 is a welding torch main body, 6 is a welding wire, 51 is a wire feeding nozzle, and 52 is a power supply tip, which is the same as FIG.

A shield gas inlet pipe 53 is connected to an upper portion of one side of the welding torch main body 5 so that the distal end of the welding wire 6 can be gas-shielded through a shield gas supply pipe 54 inside the main body. . A cooling water inlet pipe 55 and an outlet pipe 56 are connected to the other upper portion of the welding torch main body 5 so that the welding torch main body 5 can be cooled with cooling water through a water supply pipe 57 and a drain pipe 58 inside the main body. It has become.

A DC motor 7 is provided on the welding torch main body 5.
The output shaft of the DC motor 7 is connected to the wire feeding nozzle 51 via gears 71 and 72.
A circular frame 83 is provided on the welding torch main body 5 via support legs 80, and the photosensor fixing jig 8 is attached to a point symmetric position on the frame 83. 8 in the figure
Reference numeral 1 denotes a rotating plate fitted to the wire feed nozzle 51 so as to be sandwiched by the photosensor fixing jig 8, and 82 denotes a light passage hole.

With such a configuration, the DC motor 7
Starts, the wire feeding nozzle 51 and the rotating plate 81 rotate via the gears 71 and 72. As a result, the light passage hole 82 passes under the photosensor fixing jig 8, the number of rotations or the angle of rotation of the wire feed nozzle 51 is recognized, and the signal is transmitted to the DC motor 7 through a control device (not shown). The number of rotations and the rotation angle or inversion are controlled. As a result, the movements of the power supply tip 52 and the welding wire 6 in the groove 2 can be freely controlled.

After the above preparations, a welding power source (not shown) is turned on, electric power is supplied to the welding torch main body 5, an arc is generated from the tip of the welding wire 6, and the welding wire 6 is turned on.
Continuously, and moving the welding torch main body 5 in the welding direction, it is possible to realize high-quality narrow groove welding without poor penetration. At this time, the angle θ of the welding torch body 5 is in the range of 0 ° ≦ θ ≦ 15 °, and the eccentric angle φ of the wire feed port is in the range of 7 ° ≦ φ ≦ 20 °.

[0018]

As described above, according to the present invention, insufficient penetration at the bottom corner of a narrow groove can be eliminated in vertical, upward and all-position welding. Further, the molten metals (beads) are firmly melt-bonded and laminated so that no gap is generated, and sufficient welding strength can be secured.
In particular, the present invention sets the torch angle θ to θ>
By tilting the torch advance angle of 0 °, the wire
Using the power of the kinetic energy of splashed droplets, the shape of molten metal
The shape of the arc is curved concavely to the groove bottom.
So that there is no gap between the molten metals.
Laminate firmly by melting and joining so that it does not
The molten metal can be sufficiently melted into the corners of the surface
You.

[Brief description of the drawings]

FIG. 1 is a view showing a welding wire turning state in a groove of a turning electrode type welding torch.

FIG. 2 is a view showing a tilt of a rotary electrode type torch and a rotation state of a welding wire.

FIG. 3 shows the attitude of the rotating electrode type torch and the trajectory of the tip of the wire.
FIG. 5 is an explanatory diagram showing a relationship between the shape of a bead and the shape of the bead.

FIG. 4 shows the torch angle and the rotation electrode type torch of the present invention .
It is explanatory drawing which shows the suitable range of a wire eccentric angle.

FIG. 5 is a diagram for use when performing the narrow groove welding method according to the present invention .
1 is a structural view of a rotating electrode type welding torch to be used.

FIG. 6 is an explanatory view of poor penetration occurring in conventional narrow groove welding.
It is.

FIG. 7 FIG. 4 is an explanatory diagram of an ideal penetration state of narrow groove welding.
You.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Weld metal 2 Groove 3 Base material 5 Welding torch main body 6 Welding wire 51 Wire feeding nozzle 52 Power supply tip θ Angle of welding torch main body φ Eccentric angle of wire feeding port

──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Yosaburo Mabuchi 1-1, Akunoura-cho, Nagasaki City, Nagasaki Prefecture Mitsubishi Heavy Industries, Ltd. Nagasaki Shipyard (72) Inventor Yasuhiro Senguchi 1-1, Akunoura-cho, Nagasaki City, Nagasaki Prefecture Mitsubishi Heavy Industries, Ltd. Nagasaki Shipyard (56) Reference JP-A-56-126078 (JP, A) JP-A-58-176073 (JP, A) JP-A-57-11781 (JP, A) JP-A Sho 51 JP-14851 (JP, A) JP-A-53-42154 (JP, A) JP-A-2-37967 (JP, A) JP-A-51-28550 (JP, A) JP-A-3-52769 (JP, A) (58) Field surveyed (Int. Cl. ⁶ , DB name) B23K 9/173 B23K 9/29

Claims (1)

(57) [Claims] 1. In vertical, upward and all position welding
In a gas shield consumable electrode type arc welding method, a torch angle θ is inclined at a torch advance angle of θ> 0 ° with respect to a welding progress direction using a welding torch provided with a power supply tip having a wire feed port, and The tip of the wire protruding from the power supply tip at the tip of the main body is inclined with respect to the axis of the welding torch, and the power supply tip is rotated to rotate the wire tip in the direction opposite to the welding progress direction, so that scattered droplets of the wire A narrow groove welding method characterized by forming an arc-shaped weld metal that is concavely curved with respect to the groove bottom surface by the kinetic energy of the groove and laminating the weld metal.