JPH0671654B2 - High-speed rotating arc fillet welding method - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a high-speed rotary arc fillet welding method for performing fillet welding of, for example, T-joints and corner joints, and more particularly to securing penetration of beads of unequal leg length. Is.

[Conventional technology]

FIG. 6 is an explanatory view showing conventional fillet welding. For example,
In order to form a bead 3 having an unequal leg length in which the lower plate leg length l ₁ is longer than the vertical plate leg length l ₂ on the standing plate 2 erected on the lower plate 1 in a downward horizontal posture, as shown in FIG. Welding is performed by shifting the target position of 4 to the lower plate 1 side.

[Problems to be solved by the invention]

In the conventional fillet welding in the downward horizontal posture as described above, the shape of the bead 3 is a finger shape having a deep central portion and a narrow width as shown in FIG. Since the target position of the nozzle 4 is shifted to the lower plate 1 side, there is a problem that it is difficult to secure the penetration of the groove route 5.

Further, depending on the welding conditions, there is a fundamental problem that undercuts 6 are likely to occur on the standing plate 2 as shown in FIG. 7, and the formation of small leg long beads by high speed welding, or vice versa, high current low speed welding. There was a problem with the formation of the long leg bead.

The present invention has been made to solve the above problems, and an object thereof is to propose a high-speed rotating arc fillet welding method capable of ensuring the penetration of beads of unequal leg length and forming good beads. It is what

[Means for solving problems]

The high-speed rotating arc fillet welding method according to the present invention, in the fillet welding of unequal leg length, which is performed by rotating the electrode nozzle to rotate the tip of the wire passing through the electrode nozzle to rotate the arc at high speed, ) range of rotational speed of the arc, the lower the ratio l ₁ / l ₂ of the upright plate leg l ₁ and lower plate leg l ₂ is the No (Hz) the rotational speed of an extreme value 0.5No (Hz), The upper limit is 3 No (Hz), (b) the rotating diameter of the arc is 1 mm or 6 mm, and (c) the rotating direction of the arc is above the electrode nozzle when the standing plate is arranged on the right side of the welding proceeding direction. When viewed from above, when the standing plate is arranged on the left side with respect to the welding proceeding direction, the bead of unequal leg length is welded in a downward horizontal posture by rotating clockwise when viewed from above the electrode nozzle.

[Action]

In this invention, since the molten pool is easily spread to the peripheral portion by rotating the arc at a high speed, the bead shape is flattened and the penetration is secured. Further, by rotating the arc in a certain direction with respect to the standing plate, a bead having an unequal leg length in which the lower plate leg length is larger than the standing plate leg length is favorably formed.

〔Example〕

FIG. 1 is a perspective view showing an outline of an embodiment of the present invention. In FIG. 1, reference numeral 7 is an electrode nozzle for performing fillet welding of a standing plate 2 erected on a lower plate 1, and the electrode nozzle 7 is rotatable. It is rotated by the motor 8. By the rotation of the electrode nozzle 7, the wire 9 passing through the eccentric hole of the current-carrying chip provided at the tip of the electrode nozzle 7 is rotated, and the corners of the lower plate 1 and the vertical plate 2 are welded while the arc 10 is rotated at a high speed. , The bead 3 is formed on the groove route 5. In addition, 11 is a molten pool.

As shown in FIG. 2 by the electrode nozzle 7, the lower plate leg length
When l ₁ forms an unequal leg length bead 3 that is larger than the standing plate leg length l ₂ , the arc 10 is defined as a high-speed rotating arc.
This is because by rotating the depression of the molten pool 11 pushed down by the rotation of the arc 11, the molten pool 11 can be easily expanded to the peripheral portion.

Using the diffusion effect around the molten pool 11, the lower plate leg length l ₁
The shape of the bead is related to the rotating direction and the rotating speed of the arc 10 when the bead 3 having a large unequal leg length is formed.

FIG. 3 shows that the target position of the electrode nozzle 7 is the groove route 5, the arc rotation speed N when fillet welding is performed under the conditions of a welding current of 300 A and a welding speed of 22 cm / min, and the lower plate leg length l ₁ . The relationship of the standing plate leg length l ₂ , that is, the leg length ratio l ₂ / l ₁ is shown.
In FIG. 3, the solid line indicates that the arc rotation direction is counterclockwise when viewed from above the electrode nozzle 7 when the standing plate 2 is arranged on the right side with respect to the welding proceeding direction. Is arranged on the left side with respect to the welding advancing direction, it shows a case of clockwise rotation when viewed from above the electrode nozzle 7, that is, clockwise (hereinafter referred to as L rotation).
The chain line indicates the case where the arc rotation direction is opposite to the L rotation direction (hereinafter referred to as R rotation).

If the arc rotation direction is L rotation under the above welding conditions,
As shown by the solid line in the figure, when the arc rotation speed N is 7 Hz (420 rotations / minute), the leg length ratio l ₂ / l ₁ becomes the minimum, and the lower plate leg length l ₁
A bead with an unequal leg length that maximizes is formed. Leg length ratio l ₂ / l
_{If the} arc rotation speed at which ₁ is the minimum is No, this arc rotation speed No depends on the values of the welding current I and welding speed V. If this ratio V / I increases, the rotation speed No also increases. ,
By determining the welding current I and the welding speed V, the arc rotation speed No that minimizes the leg length ratio l ₂ / l ₁ is determined.

Based on this arc rotation speed No, the change in the leg length ratio l ₂ / l ₁ with respect to the arc rotation speed N is as shown in FIG. 3 when the arc rotation speed range is 0.5No (Hz) to 3No (Hz). In the range of, the leg length ratio l ₂ / l _{1 is about} 0.85 or less, and the lower plate leg length l ₁
Can form a bead having an unequal leg length larger than the leg length l ₂ of the standing plate.

When the arc rotation direction indicated by the chain line in FIG. 3 is R rotation, when the arc rotation speed N is No, the leg length ratio l ₂ / l ₁
Is maximized, the effect of scooping up the molten metal is produced, and the bead length of the bead can be increased.

On the other hand, when the shape of the bead is examined, in the case where the rotational speed N of the arc is zero, that is, in the case of the conventional horizontal fillet welding, as shown by the chain line in FIG. Since 3a is formed and the penetration on the side of the standing plate 2 is small,
Shift the target position of the electrode nozzle to the lower plate 1 side and lower plate leg length l ₁
When a bead having a large unequal leg length was formed, it became a defective bead with a small penetration.

However, if the rotation speed No of the arc is increased, the molten pool is likely to spread to the peripheral portion, and thus the flat bead 3b having a shallow central portion and a wide width is formed, and the penetration in the bead width direction is increased. Therefore, when forming a bead having an unequal leg length, the target position range for ensuring the penetration of the rotating electrode nozzle 7 is widened, and a good bead is formed even if a bead having a large lower leg length l ₁ is formed. Can be formed.

Further, the leg length ratio l ₂ / l ₁ varies depending on the arc rotating diameter D even if the welding current I and the welding speed V are constant. For example, the welding current I is 30
When 0 (A), welding speed V is 22 (cm / min), arc rotation speed is 7 (Hz) and arc rotation direction is L rotation, fillet welding is performed by changing arc rotation diameter D. The results are shown in FIG. In FIG. 5, the horizontal axis indicates the arc rotation diameter D, and the vertical axis indicates the leg length ratio l ₂ / l ₁ where 1.0 is the leg length ratio l ₂ / l ₁ obtained when the arc is not rotated. Fifth
As shown in the figure, the larger the rotating diameter D of the arc, the easier the formation of the unequal leg length bead having the large lower plate leg length l ₁ . However, when the rotating diameter D of the arc becomes 8 mm, an undercut occurs on the standing plate 2. Therefore, the range of the arc rotation diameter D is 1 mm.
By setting the thickness to be 6 mm, it is possible to form a good bead having an unequal leg length without defects.

Although the above embodiment has been described with respect to the T-joint, it can be similarly applied to a corner joint.

〔The invention's effect〕

As described above, according to the present invention, since the lower plate leg length is formed by the arc rotating in the constant direction with respect to the standing plate to form the unequal leg length bead larger than the standing plate leg length, it is possible to sufficiently secure the penetration. This has the effect of easily forming a bead having an irregular leg length.

[Brief description of drawings]

FIG. 1 is a perspective view showing an embodiment of the present invention, and FIG.
FIG. 3 is a side view showing a welded portion of the embodiment shown in FIG. 3, FIG. 3 is a characteristic diagram of arc rotation speed N and leg length ratio l ₂ / l ₁ , FIG. 4 is an explanatory diagram showing a bead shape, and FIG. Is a characteristic diagram of the arc rotation diameter D and leg length ratio l ₂ / l ₁ , FIG. 6 is an explanatory diagram showing conventional fillet welding, and FIG. 7 is an explanatory diagram of beads in conventional fillet welding. 1 ... Lower plate, 2 ... Standing plate, 3 ... Bead, 5 ... Groove route, 7 ... Electrode nozzle, 8 ... Rotation motor, 9 ...
Wire, 10 ... Arc, 11 ... Melting pool, l ₁ ...... Lower plate leg length, l ₂・ ・ ・ Standing plate leg length.

Claims (1)

[Claims] 1. In fillet welding of unequal leg length, which is performed while rotating the tip of a wire passing through the electrode to rotate the arc at a high speed by rotating the electrode, the range of the rotating speed of the arc is: Let No (Hz) be the rotation speed at which the ratio l ₁ / l _{2 of the} standing plate leg length l ₁ to the lower plate leg length l ₂ is an extreme value.The lower limit is 0.5 No (Hz) and the upper limit is 3 No (Hz). ) The rotating diameter of the arc is 1 mm or 6 mm. (C) The rotating direction of the arc is left when viewed from above the electrode nozzle when the standing plate is arranged on the right side with respect to the welding proceeding direction. On the other hand, when a standing plate is arranged on the left side, the bevel of the unequal leg length is welded in a downward horizontal position by rotating it clockwise when viewed from above the electrode nozzle, which is a high-speed arc fillet welding method.