JP3944006B2 - How to remove welding distortion - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention is applied to a ship hull welded portion of a ship and occurs in the vicinity of a weld bead formed in a welded portion of steel materials such as a weld bead accompanying fillet welding of two steel materials welded at right angles to each other. The present invention relates to a method for removing welding distortion.
[0002]
[Prior art]
When welding a ship's hull, it is inevitable that welding distortion will occur in the vicinity of the fillet weld bead parts of two steel materials welded at right angles to each other. It is required to remove the steel material without lowering by means such that the steel material after the welding distortion is removed becomes the target welding position.
Conventionally, a gas burner is used as means for removing the weld distortion of the weld bead part, and the weld bead part and the vicinity thereof are heated by a high-temperature gas such as argon gas from the gas burner to correct the deformation of the steel material due to the weld distortion. Many means are used.
[0003]
[Problems to be solved by the invention]
In the means for heating the weld bead portion and the vicinity thereof with the high-temperature gas using the gas burner as described above, the welding distortion removing operation itself is simple, but the gas is used to heat the weld bead portion and the vicinity thereof. However, it is difficult to adjust the heat input, and the welding distortion is removed by adding human factors such as the experience of the operator. Is impossible.
In addition, in such a conventional technique, since a high-temperature gas from a gas burner is used, there is a risk of fire due to the high-temperature gas, and there is a problem in work safety.
And so on.
[0004]
In view of the problems of the prior art, the present invention can reliably remove the welding distortion generated in the vicinity of the weld bead formed in the welded portion between the steel materials so that the steel material after welding becomes the target welding position. In addition, an object of the present invention is to provide a method for removing welding distortion that enables construction while maintaining high safety.
[0005]
[Means for Solving the Problems]
In order to solve this problem, the present invention provides a method for removing weld distortion generated in the vicinity of a weld bead formed in a welded portion of a steel material as an invention according to claim 1, using a TIG (tungsten inert gas) welder, When the welding bead is heated with an arc from a TIG welder to remove welding distortion in the vicinity of the welded portion of the steel material, the deformation amount due to welding of the steel material is measured, and the measured value of the deformation amount is used to measure the deformation amount. The amount of heat input to the weld bead by an arc from a TIG welder is set, and heating conditions including current and voltage applied to the electrodes of the TIG welder are set based on the amount of heat input . A removal method is proposed.
[0006]
[0007]
In the present invention, it is preferable to configure as in claims 2 and 3 .
That is, in claim 2 , the TIG welder is supported by a traveling device and travels along the weld bead, and the moving condition of the TIG welder including the traveling speed of the traveling device is set based on the heat input.
Moreover, in Claim 3 , when the said heat input is cooled after heating the said welding bead by the said arc and it returns to normal temperature based on the measured value of the deformation amount by the said welding, the said steel materials will be in a target welding position. Set to.
[0008]
According to this invention, the welding bead is heated while adjusting the strength of the arc by controlling the current of the TIG welder, so that the amount of heat input to the heating part can be adjusted as compared with the heating by the high temperature gas from the conventional gas burner. It is easy, and it becomes possible to reliably remove the welding distortion so that the steel material after the welding distortion removal becomes the target welding position.
In particular, according to the first, second, or third aspect, the amount of heat input to the weld bead by the arc from the TIG welding machine is set using the measured value of the deformation amount due to welding of the steel material, and based on the amount of heat input. TIG welding machine that sets the heating conditions including the current and voltage applied to the electrodes of the TIG welding machine, and further includes the traveling speed of the traveling device that supports the TIG welding machine in a welded part with a long welding length such as a ship Therefore, the amount of weld strain removed in the vicinity of the weld bead in the welded portion of the steel material can be set quantitatively regardless of the weld length, and the steel material after the weld strain is removed. Can be accurately set as the target welding position, and the welding distortion can be removed automatically and continuously without requiring any human factors such as operator experience. .
[0009]
Also, since the welding distortion is removed by locally heating only the weld bead with an arc from the electrode of the TIG welder, the surroundings of the weld are heated at a high temperature, such as heating the weld with high-temperature gas from a conventional gas burner. An atmosphere can be avoided, and the welding distortion can be removed while maintaining high safety.
[0010]
Therefore, according to such an invention, the welding strain generated in the vicinity of the weld bead formed in the welded portion between the steel materials is automatically and continuously processed, and the steel material after the welding strain is removed is brought to the target welding position. Thus, the welding distortion can be removed while maintaining high safety.
[0011]
Further, in claim 1, as in claim 4 , the TIG welder may use an electrode having a tip formed in a curved shape or an obtuse conical shape.
If comprised in this way, an arc angle can be expanded and a welding bead can be heated entirely, without damaging a welding bead with an electrode.
[0012]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, the present invention will be described in detail with reference to the embodiments shown in the drawings. However, the dimensions, materials, shapes, relative arrangements, and the like of the component parts described in this example are not intended to limit the scope of the present invention only to specific examples unless otherwise specified. Only.
[0013]
FIG. 1 is a flowchart showing a welding strain removing operation procedure in the vicinity of a weld bead accompanying fillet welding of a steel material according to an embodiment of the present invention, and FIG. 2 is an explanatory diagram of a welding strain removing method in a fillet weld portion of the steel material. is there. FIG. 3A is a cross-sectional view of the main part showing the vicinity of the tip of the electrode of the TIG welder for removing weld distortion, and FIG. 3B is a side view of the main part showing an example of the shape of the electrode. FIG. 4 is a structural diagram of a welding strain removing device using a TIG welding machine and a traveling device in a hull welded portion, and FIG. 5 is a diagram showing a relationship between a tilt angle of a steel material and a heat input amount.
[0014]
In FIG. 4 which shows the structure of the welding distortion removing apparatus in the hull welded portion, the welded portion is constituted by continuously filling a vertical steel plate 2 onto a horizontal steel plate 1. 3 is a weld bead of the fillet weld. Reference numeral 10 denotes a TIG welder, which is supported by a traveling device 4 that travels on the horizontal steel plate 1 along the weld bead 3 via a support 5 and is moved by the traveling device 4 in any direction and at any speed. It is possible.
[0015]
Next, a method for removing welding distortion in a hull welded part using the TIG welder 10 will be described.
In FIG. 2 showing the fillet welded part of the hull, the vertical steel plate 2 continuously welded on the horizontal steel plate 1 is positioned at a right angle (θ = 90 °) indicated by a two-dot chain line in the figure due to welding distortion. ) With an inclination angle θ.
That is, when welding two steel plates 1 and 2 extends only S ₁ by welding heat, contraction amount S2, shrinkage greater than the elongation amount S ₁ by being cooled to room temperature. When continuous fillet weld perpendicular steel plate 2 on the horizontal steel plate 1, the vertical steel plates 2, corresponds to the difference between such contraction amount S ₂ and the elongation amount S ₁ (S 2 _{-S 1)} Inclined at an inclined angle θ. 3 is a fillet weld bead.
Reference numeral 11 denotes an electrode of the TIG welding machine 10 which is attached so as to be inclined with respect to the upper surface of the horizontal steel plate 1 by an angle α and to maintain a gap δ with the surface of the weld bead 3.
[0016]
In removing the welding distortion of the fillet welded portion in which the vertical steel plate 2 is inclined at the inclination angle θ by the TIG welding machine 10, first, the inclination angle θ of the vertical steel plate 2 is set as shown in FIG. It measures using a well-known angle measuring device etc. (step (1) of FIG. 1).
Next, the amount of heat input Q required to heat the weld bead 3 by the arc 14 (see FIG. 3) from the electrode 11 of the TIG welder 10 is calculated using the measured value of the tilt angle θ.
Here, as shown in FIG. 5 as an example of a relationship diagram of the inclination angle θ and the heat input Q, the relationship between the inclination angle θ and the heat input Q is set in advance through experiments, simulations, and the like. Yes. From this relationship diagram, a set value of the heat input Q corresponding to the measured value of the inclination angle θ is obtained (step (2)).
[0017]
Next, based on the set value of the heat input Q, the voltage V and current I applied to the electrode 11 of the TIG welder 10 are determined from the characteristic values of the TIG welder 10 and set (step (3)).
Next, the voltage V and current I are applied to a control panel (not shown) of the TIG welding machine 10.
The welding angle such as the inclination angle α of the electrode 11 with respect to the upper surface of the horizontal steel plate 1 and the gap δ between the electrode 11 and the surface of the weld bead 3 are input, and a control panel (not shown) of the traveling device 4 is set. ) Is input a travel condition such as the travel speed U of the travel device 4 (step (4)).
[0018]
When the setting of the welding conditions and the traveling conditions of the traveling device 4 is completed, the surface of the weld bead 3 is moved by the TIG welding machine 10 under the welding conditions while the traveling device 4 is traveling under the traveling conditions. Heat.
FIG. 3A shows the heating condition of the surface of the weld bead 3. In the figure, the electrode 11 of the TIG welder 10 is set to the inclination angle α and the gap δ, and the electrode 11 is set as described above. The arc 14 corresponding to the generated voltage V and current I is discharged to the weld bead 3, and a gas 15 such as argon gas or carbon dioxide gas from the passage 13 between the outer periphery of the electrode 11 and the inner periphery of the protective cylinders 1 and 2. And the surface of the weld bead 3 is heated (step (5)).
When the welding bead 3 is heated, the vertical steel plate 2 that is inclined at the inclination angle θ by the welding strain is positioned at a right angle (θ = 90 °) indicated by a two-dot chain line in FIG. 2, that is, a target welding position. Returned to
[0019]
According to such an embodiment, the welding bead 3 is heated while adjusting the strength of the arc 14 by controlling the current of the TIG welding machine 10, so that the heat input Q to the heating part can be easily adjusted, and after the welding distortion is removed. Thus, it is possible to reliably remove the welding distortion so that the steel plates 1 and 2 become the target welding positions.
That is, the heat input Q to the weld bead 3 by the arc 14 from the TIG welder 10 is set using the measured value of the inclination angle θ by welding the steel plates 1 and 2, and the TIG welder 10 The welding speed (heating condition) including the current I and the voltage V to be applied to the electrode 11 is set, and the traveling speed of the traveling device 4 that supports the TIG welder 10 in a welded portion having a long welding length such as a ship. Since the moving condition of the TIG welder 10 including U is set based on the heat input Q, the removal amount of the weld distortion in the vicinity of the weld bead 3 in the welded portion of the steel plates 1 and 2 regardless of the weld length. Can be set quantitatively and accurately. In addition, the welding distortion can be removed automatically and continuously without requiring any human factor such as the operator's experience.
[0020]
Next, FIG. 3B shows three examples of the shape of the tip 11a of the electrode 11. In the figure, (B1) is an electrode 11 having a sharp tip 11a, and in this case, the weld bead 3 may be damaged by the sharp tip 11a, and the arc angle cannot be widened.
(B2) is a curved electrode 11 having a tip 11a having a radius R, and (B3) is an electrode 11 having a tip 11a formed in a conical shape having an obtuse angle (β> 90 °). The tip 11a is a curved electrode and an electrode formed in an obtuse conical shape, and heats the weld bead 3 entirely by widening the angle of the arc 14 without damaging the weld bead 3 with the electrode tip 11a. This is a preferred structure.
[0021]
【The invention's effect】
As described above, according to the present invention, since the weld bead is heated while adjusting the strength of the arc by current control based on the set value of the heat input to the weld bead in the TIG welder, the high temperature gas from the conventional gas burner is used. The amount of heat input to the heating part can be easily adjusted as compared with the heating by means of, and the welding distortion can be surely removed so that the steel material after the welding distortion is removed becomes the target welding position.
In addition, in a welded part with a long weld length, such as a ship, the moving condition of the traveling device that supports the TIG welder is set based on the amount of heat input. Therefore, regardless of the weld length, the welded part of the steel material The amount of weld distortion removed in the vicinity of the weld bead can be set quantitatively and accurately.
As a result, the welding distortion can be removed automatically and continuously without requiring any human factors such as the operator's experience.
Also, since welding distortion is removed by locally heating only the weld bead with an arc from the electrode of the TIG welder, it is possible to avoid a high-temperature atmosphere around the welded part and maintain high safety while welding. Distortion removal work can be performed.
[0022]
Therefore, according to the present invention, the weld strain generated in the vicinity of the weld bead formed in the welded portion between the steel materials is automatically and continuously processed so that the steel material after removal of the weld strain is brought to the target welding position. Thus, the welding distortion can be removed while maintaining high safety.
Furthermore, if comprised like Claim 4 , an arc angle can be expanded and a weld bead can be heated entirely, without damaging a weld bead with an electrode.
[Brief description of the drawings]
FIG. 1 is a flowchart showing a procedure for removing welding distortion in the vicinity of a weld bead associated with fillet welding of a steel material according to an embodiment of the present invention.
FIG. 2 is an explanatory diagram of a welding strain removal method in a fillet weld of a steel material.
FIG. 3A is a cross-sectional view of a main part showing the vicinity of an electrode tip of a TIG welder for removing welding distortion, and FIG. 3B is a side view of the main part showing an example of the shape of the electrode.
FIG. 4 is a structural diagram of a welding strain removing device using a TIG welding machine and a traveling device in a hull welded portion.
FIG. 5 is a diagram showing the relationship between the inclination angle of a steel material and the amount of heat input.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Horizontal steel plate 2 Vertical steel plate 3 Weld bead 4 Traveling apparatus 10 TIG welding machine 11 Electrode 1, 2 Protective cylinder 13 Passage 14 Arc

Claims (4)

In a method for removing welding distortion generated in the vicinity of a weld bead formed in a weld portion of a steel material, a TIG (tungsten inert gas) welder is used, and the weld bead is heated by an arc from the TIG welder to weld the steel material. When removing the weld distortion in the vicinity of the part , measure the amount of deformation due to welding of the steel material, using the measured value of the amount of deformation to set the amount of heat input to the weld bead by the arc from the TIG welder, A method for removing welding distortion, comprising setting heating conditions including current and voltage applied to an electrode of the TIG welder based on the heat input . The travel condition of the TIG welder including the travel speed of the travel device is set based on the heat input, and the TIG welder is supported by a travel device and travels along a weld bead. The method of removing welding distortion as described. Based on the measured value of deformation due to welding, the amount of heat input is set so that the steel material becomes a target welding position when the welding bead is cooled by heating with the arc and then returned to normal temperature. The method for removing welding distortion according to claim 1 . The TIG welding machine, a method for removing the welding strain according to claim 1, characterized by using an electrode tip portion is formed in a curved shape or obtuse conical.

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