JP2953286B2 - Rotary electrode TIG welding method for thin plates - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to lap welding of thin plates, and more particularly to a TIG welding method for forming a bead by melting a base material on an upper plate and a lower plate side. The bead surface shape is good and wide
The present invention relates to a TIG welding method for rotating a thin plate to form a shallow penetration weld by an electrode.

[0002]

2. Description of the Related Art Conventionally, a torch follows a welding line in lap welding of thin plates by manual operation of an operator, or, although expensive, a contact type sensor is used for the detection, or a complicated image is formed by an optical type sensor. Processing method was adopted. In order to automate welding, the latter two methods are required, but in any case, in addition to the torch, it is necessary to provide a unique device called a sensor near the torch. Due to dimensional restrictions, a certain gap was generated between the position and the position. Therefore, it is necessary to control the torch position by giving a time difference corresponding to the interval, and only complicated control can be performed with a limited accuracy. Japanese Patent Publication No. 61-17591 discloses an arc sensor groove tracing method using a welding arc itself as a sensor without using a separate sensor and having excellent accuracy in welding line profiling. This arc sensor groove profiling method changes the arc characteristics due to torch swing in the groove,
After time integration with the half cycle of the left and right swings based on the center of the swing width, and then comparing them, so that both become equal,
That is, by controlling the movement of the torch swing center so that the difference between the two becomes zero, the groove line following is achieved. However, there is a drawback that the method cannot be applied to a joint in which one groove does not exist, such as a weld line of a lap welded part of a thin plate. Also, in the method disclosed in Japanese Patent Publication No. 1-4875 (JP-A-57-91877), a groove copying method using electrode rotation is disclosed. Could only be applied when there was.

[0003]

In order to automate welding, a groove is detected to automatically control a torch position with respect to a two-dimensional displacement of a welding line that changes every moment during welding. A torch position movement adjusting mechanism using a sensor and a detection sensor is required. Conventionally, the torch follows the welding line in the lap welding of thin plates, either by the operation of the welding operator, or it is expensive for automation of welding, but using a contact sensor for detection, or complicated by an optical sensor It is necessary to adopt a special image processing method, but in any case, in addition to the torch, it is necessary to provide a unique device called another sensor near the torch, and the dimensional difference between the detection position and the control target position is required. There is a certain interval due to restrictions, and it is necessary to control the torch position by giving a time difference according to the interval, and there is a problem that only a control with a limited accuracy can be performed for a complicated case. In addition, in the lap welding of thin plates, good or required in non-consumable electrode arc welding methods such as TIG welding and plasma welding in which a bead is formed by melting a base material on an upper plate and a lower plate side without using a filler metal. In order to obtain the desired bead surface shape, the target position of the torch must always be maintained at an appropriate position.

[0004] The present invention provides a welding line excellent in accuracy without using a separate sensor for one of the grooves, ie, a joint having no step, such as a welding line for a lap welding portion of a thin plate. It is an object of the present invention to provide a method of electrode-rotating TIG welding of a thin plate, which can perform automatic copying and, as a result, appropriately maintain a bead surface shape of a lap welded portion of the thin plate.

[0005]

SUMMARY OF THE INVENTION According to the present invention, there is provided a method for TIG welding a thin plate by rotating an electrode with a thickness of 0.5 to 2.
An electrode rotary TIG welding method for a thin plate in which an electrode rotary TIG welding is performed on an overlapped portion of a 5 mm thin plate, wherein a tungsten electrode tip provided on a welding torch having a torch inclination angle set within approximately ± 10 °. The rotating diameter is 1-4m
In the range of m, a circular motion having an appropriate rotating diameter is given according to the thickness of the sheet, and an appropriate welding current is set according to the thickness of the sheet. The arc voltage is detected during the lap welding along the welding line of the overlapped portion of the thin plate, and the center of the arc voltage in the forward direction of the rotating circle of the arc parallel to the welding line of the overlapped portion of the thin plate is detected. 5 ° or more on the left and right with reference to 18
The difference between the integral values of the arc voltage waveforms at the rotational positions of the electrodes in two predetermined angle ranges of 0 ° or less is determined, and the welding torch is moved in a direction perpendicular to the welding line in a plane parallel to the thin plate surface. In the range of 0.5 to 0.8 mm on the side of the upper plate from the part, when set at an appropriate position according to the plate thickness.
The difference between the respective integral values of the arc voltage waveforms at the rotation positions of the electrodes in two predetermined angle ranges is set as a reference value at the welding torch target position, and the difference between the integral value during welding and the reference value at the welding torch target position is set. And control the movement of the welding torch in a direction perpendicular to the welding line in a plane parallel to the thin plate surface so that the difference becomes zero so that the welding torch is properly adjusted with respect to the welding line at the overlapping portion of the thin plates. The position is controlled.

[0006]

FIG. 1 is a block diagram showing the entirety of an electrode rotary TIG welding apparatus used in a thin plate electrode rotary TIG welding method according to one embodiment of the present invention, and FIG. FIG. 3 is a sectional view showing an electrode rotating TIG torch, FIG. 3 is an explanatory view showing a torch inclination angle of the electrode rotating TIG torch, and FIG.
FIG. 5 is a schematic diagram showing a copying signal detection method of the groove copying method, and FIG. 5 is an explanatory diagram showing a difference in bead shape depending on a target position. In the figure, reference numeral 1 denotes an upper plate 1 on a lower plate 1a which is a material to be welded.
2 is a tungsten electrode which is a non-consumable electrode positioned on a groove of the base material 1, 3 is a rotary drive motor, 3a is a shaft of the rotary drive motor 3, and 4 is a shaft attached to the shaft 3a. A driving gear provided with a high-speed rotation by a rotary drive motor 3, a driven gear 5 provided with a high-speed rotation by a driving gear 4, and a cylindrical electrode holder 6 holding a tungsten electrode 2 at a collet chuck 6a provided at a tip thereof. The member 6 b is a gas cup provided below the electrode holding member 7 and surrounding the tungsten electrode 2.

An upper self-aligning bearing 7 rotatably supports the upper part of the electrode holding member 6, and an upper self-aligning bearing 8 is held eccentrically by a fixed amount from the center of rotation of the ring. Is an eccentric ring that holds a predetermined amount of eccentricity from the rotation center of the driven gear 5, and forms an eccentric ring member with the upper self-aligning bearing 7. 9
Is an eccentric ring holding case that houses the eccentric ring 8 integrally, and is integrally attached to the driven gear 5. 10
Is a lower self-aligning bearing that supports the lower part of the electrode holding member 6. 11 is a rotation angle position of the rotation drive motor 3;
That is, it is a rotational position detector such as an encoder that detects the rotational angle position of the tip of the tungsten electrode 2. In addition, a welding voltage is applied between the tungsten electrode 2 and the base material 1 which are held by the electrode holding member 6 and located on the axis thereof by a constant current welding power supply device described later, and an arc is generated.
Reference numeral 12 denotes an electrode rotation TIG torch including the tungsten electrode 2 and the rotation position detector 11.

Reference numeral 12 denotes an electrode rotating TIG torch of the electrode rotating type TIG welding device, and the tungsten electrodes 2 to 2 shown in FIG.
It comprises a rotation position detector 11. 13 is a constant current welding power supply, 14 is an arc voltage detector for detecting an arc voltage between the tungsten electrode 2 and the base material 1, 15 is a rotation speed setting device for rotating the tungsten electrode 2 at a desired rotation speed, 16 is This is a rotation motor driver that drives the rotation drive motor 3 based on the rotation speed set value set by the rotation speed setting device 15.

Reference numeral 17 denotes an arc voltage reference setting device for setting a reference arc voltage between the tungsten electrode 2 and the base material 1, and 18 denotes a difference between a detection value of the arc voltage detector 14 and a reference value of the arc voltage reference setting device 17. A differential amplifier 19 for performing comparison operation is provided with a torch proximity / separation mechanism 2 based on the output of the differential amplifier 18.
0 is a proximity / separation motor controller for controlling the rotation of the proximity / separation motor 21; 22 is a lateral movement mechanism controller for controlling the rotation of the lateral movement motor 24 of the torch lateral movement mechanism 23;
5 is a torch approach / separation mechanism 20 and a torch lateral movement mechanism 23
And a welding bogie that travels on the base material 1 while supporting it.

Reference numeral 26 denotes a timing circuit for outputting a signal for operating an integrator with respect to detection signals in two predetermined angular ranges set in advance based on the position detection signal of the rotational position detector 11, and 27a and 27b denote arc voltage detectors 14. The arc voltage detection signal is input and the timing circuit 26
The integrator 28 also receives a signal from
A first comparator for calculating a difference between the integrated values output from the output terminals 27b;
Reference numeral 29 denotes the integral value of the arc voltage waveform in two predetermined angular ranges set when the welding torch is set at an appropriate target position near the welding line in a direction perpendicular to the welding line in a plane parallel to the thin plate surface. A torch aiming position setting device that outputs the difference as a reference value at the welding torch aiming position, 30 is a difference between the difference between the integrated value output from the first comparator 28 and the reference value output from the torch aiming position setting device 29. The second comparator 31 calculates the control signal based on the difference between the integral value output from the second comparator 30 and the reference value so that the difference becomes zero. This is a welding line profiling control circuit to output. The torch target position setting device 29 has a first comparator 28.
By inputting the output of (1), automatic sampling can be performed, and further automation becomes possible.

Next, the thin electrode rotating type TIG of the above embodiment is described.
The operation of the electrode rotating TIG welding device used in the welding method will be described. First, the operation of the rotary electrode TIG torch 12 used in the rotary electrode TIG welding method for a thin plate of the embodiment shown in FIG. 2 will be described. When the rotation drive motor 3 rotates, the rotation is transmitted to the eccentric ring 8 via the drive gear 4, the driven gear 5, and the eccentric ring holding case 9. Since the eccentric ring 8 rotatably holds the upper self-aligning bearing 7 that rotatably supports the upper part of the electrode holding member 6 at an eccentric position separated by a certain distance from the ring rotation center,
The upper part of the electrode holding member 6 turns around the rotation axis thereof as the eccentric ring 8 rotates. Further, the lower part of the electrode holding member 6 is coaxially attached to the center of rotation of the eccentric ring 8 and is also held by the lower self-aligning bearing 10 fixed around its periphery. By the action of the ring 8, the tip of the tungsten electrode 2 extending downward from the lower portion of the electrode holding member 6 performs a slidable circular motion with the lower self-aligning bearing 10 as a fulcrum of the center of rotation.

When the tip of the tungsten electrode 2 is making a circular motion, the lower part of the electrode holding member 6 which holds the base of the tungsten electrode 2 is rotatably supported by a lower self-aligning bearing 10 and has a rotation center. And does not rotate itself, so that power can be directly supplied to the tungsten electrode 2 located below the electrode holding member 6 by a power supply cable (not shown). It should be noted that the upper self-aligning bearing 7 and the lower self-aligning bearing 10 may be replaced by a universal bearing having the same function as a spherical plain bearing, a unit ball bearing, or the like.

Next, the operation of the electrode rotary type TIG welding apparatus will be described. For example, when lap welding of a stainless steel thin plate having a thickness of 2 mm, the electrode rotation diameter of the tungsten electrode 2 which is a non-consumable electrode is set to 2.5 mm, the electrode rotation frequency is set to 3 to 5 Hz by the rotation drive motor 3, and constant current welding is performed. A welding current of 140 A is applied to the tip of the tungsten electrode 2 by the device 13 to give a circular motion to the tungsten electrode 2.
The lap welding is performed at a welding speed of 25 to 30 cm / min along the welding line of the base material 1 while rotating the arc generated at high speed. At this time, the torch inclination angle is maintained at an appropriate value in order to properly detect a signal of an arc voltage necessary for following the welding torch within 0 ± 10 °. As shown in FIG. 3, the torch inclination angle is 0 ° when the torch axis is perpendicular to the upper surface of the upper plate 1b, the + direction is the direction inclined toward the lower plate 1a, and the upper plate 1b The direction inclined to the side is defined as the-side.

When the torch was stationary, the arc was concentrated at one point on the weld and the area immediately below the arc was always melted. However, while the arc was being generated, the tip of the tungsten electrode 2 was mechanically formed in a substantially circular shape. Since the welding is performed by moving, the welding arc is applied to the welded portion of the base material 1 by the tungsten electrode 2.
With the rotation of the tip of the arc, the welded part moves in a circular shape, and the molten part immediately below the arc moves with a certain rotation diameter, and the heat input to the welded part of the arc is dispersed in a certain diameter Becomes
As a result, a wide and shallow penetration weld can be efficiently formed at high speed.

[0015] Due to the characteristics of the TIG arc, the effect of the rotation of the tungsten electrode 2 is determined by whether or not the arc can move through the molten portion with the rotation. In the case of the TIG arc, the electrode rotation frequency is about 20 Hz. It is a limit.
Further, the effect of dispersing the heat input is seen at a certain rotation diameter or more, and the maximum value of the rotation diameter is determined in consideration of the decrease in the melting efficiency of the base material due to the heat input dispersion. T in lap welding of thin plates
In the case of an IG arc, the appropriate turning diameter and welding current value of the tungsten electrode 2 are determined by the thickness of the thin plate and the required bead width. The required bead width is determined according to the plate thickness, and the appropriate welding current value and rotation diameter corresponding to the required bead width are obtained by experiments. Table 1 shows specific welding condition data according to the plate thickness. . Rotation diameter is 1 to 3 depending on plate thickness
By providing a circular motion with an appropriate rotation diameter in the range of 4 mm and setting an appropriate welding current, welding with an appropriate bead width was obtained. The welding condition data in Table 1 is for a welding speed of 25 to 30 cm / min. If the welding speed changes, the welding current and the like will also slightly differ.

[0016]

[Table 1]

Next, a method for following a groove line during welding will be described with reference to FIGS. 1, 4 and 5. First, the principle of the method for following a groove line will be described. Welding is performed along the welding line of the base material 1 composed of the lower plate 1a and the upper plate 1b to which the tungsten electrode 2 provided on the electrode rotating TIG torch 12 is overlap-welded. Then, as shown in FIG. 4A, the tip of the tungsten electrode 2, that is, the arc is located at the rear center C.P. From the point A, which is the R position, to the point B on the lower plate 1a side, the arc voltage detected by the arc voltage detector 14 at the rotational position on the lower plate 1a gradually increases as shown in FIG. However, at the point B, the increase of the arc voltage becomes almost maximum. Then, from the point B, the front center C. in the traveling direction of the arc rotation circle. The arc voltage gradually decreases as it comes to the point C, which is the F position, and when the arc rotates to the point D on the upper plate 1b side from the point C, the arc voltage is detected at the rotational position on the upper plate 1b side. The arc voltage detected by the detector 14 gradually decreases, and at the point D, the decrease in the arc voltage becomes almost maximum. Thereafter, the arc voltage increases from point D to point A. FIG. 4B shows the change in the arc voltage with reference to the reference voltage.
L, SR are the forward centers C.C. in the traveling direction of the rotating circle of the arc in FIG. It represents the integral value of two predetermined angle ranges θ1 and θ2 of 0 ° to 90 ° (R region) and 270 ° to 360 ° (L region) on the left and right with respect to F. Therefore,
When the arc voltages on the lower plate 1a side and the upper plate Ib side of the rotating tungsten electrode 2 are respectively detected and the voltages are compared, the center of the rotating circle at the tip of the tungsten electrode 2 is
It can be seen whether it is located at the welding line. Therefore, by detecting the arc voltage between the lower plate 1a and the upper plate 1b, comparing the detected voltages to determine the difference, and comparing the difference with a reference value at an appropriate position of the welding torch, the tungsten It can be seen whether or not the center of the rotating circle at the tip of the electrode 2 is located at the welding line of the base material 1.

Next, a groove line copying method will be described.
When the welding is performed along the welding line of the base material 1 composed of the lower plate 1a and the upper plate 1b on which the tungsten electrode 2 provided on the electrode rotary type TIG torch 12 is overlap-welded, the arc voltage detector 14 The arc voltage that is changed by the rotation of the tip of the tungsten electrode 2 is detected, and the integrators 27a, 2
7b. On the other hand, the rotation position detector 11 detects the rotation position of the rotating tungsten electrode 2 and outputs a position detection signal to the timing circuit 26. In the timing circuit 26, the forward center C.C. in the traveling direction of the rotating circle of the arc based on the position detection signal of the rotating position detector 11. On the basis of F, a predetermined angle range θ1 of, for example, 0 ° to 90 ° on the upper plate 1b side and a predetermined angle range θ of 90 °, for example, 270 ° to 360 ° on the lower plate 1a side are set.
In 2, the integrators 27a and 27b integrate the arc voltage.

The integrated values obtained by integrating the arc voltages by the integrators 27a and 27b are input to a first comparator 28. The reason why the integration is performed by the integrators 27a and 27b is to prevent the arc voltage waveform from being affected by noise. In the first comparator 28, the integrated value SL by the integrator 27a
And the integrator 27b calculates a difference ΔS between the integral values SR and outputs the difference ΔS to the second comparator 30. Torch aiming position setting device 2
In No. 9, the integral value of the arc voltage in two predetermined angle ranges θ1 and θ2 when the welding torch is set at an appropriate position near the welding line in a direction perpendicular to the welding line in a plane parallel to the thin plate surface Is set as a reference value at the target position of the welding torch, and the difference is output to the second comparator 30.
The second comparator 30 compares the difference ΔS of the integral value obtained by the first comparator 28 with the reference value ΔS0 at the welding torch target position set by the torch target position setting unit 29, and outputs the difference signal. Output to the line scanning control circuit 31. In the welding line scanning control circuit 31, the difference ΔS−Δ obtained by the second comparator 30 is used.
A lateral movement command signal that makes S0 zero is output to the lateral movement mechanism controller 22. The lateral movement mechanism controller 22 drives the torch lateral movement mechanism 23 by rotating the lateral movement motor 24 to control the lateral movement of the electrode rotating TIG torch 12 in a direction parallel to the thin plate surface and orthogonal to the welding line. The electrode TIG torch 12 is controlled to an appropriate position so that the electrode rotating TIG torch 12 comes to the welding line at the overlapping portion of the thin plates, that is, the center of the rotating circle at the tip of the tungsten electrode 2 is positioned at the welding line. It was done.

When the reference value is set to, for example, 0.7 V in the torch aiming position setting device 29, the torch aiming position becomes the torch aiming position B shown in FIG. On the other hand, if the reference value is set to, for example, 0 V, the torch aiming position becomes the torch aiming position A shown in FIG. 5 and becomes a concave bead, which is inappropriate. Further, when the reference value is set to, for example, 1.0 V, the torch target position becomes the torch target position C shown in FIG. 5 and becomes a convex bead, which is inappropriate. In this way, it can be adjusted so that the arc always exists at an appropriate target position in parallel with the welding line.
Further, since the arc voltage during welding is detected, the arc voltage is signal-processed, and the center of the arc rotation circle is controlled to be located at the target position, so that the electrode rotation TIG torch 12 is automatically followed. The welding arc itself serves as a sensor, and the electrode rotation T along the welding line during the welding process.
The IG torch 12 can be accurately followed.

In the above embodiment, the arc aiming position is delicate, and if it changes by 0.2 to 0.3 mm, the bead shape may deteriorate. Also, the target position changes depending on the plate thickness, and the bead shape changes depending on the target position.
In the case of a thin plate having a thickness of about 0.5 to 2.5 mm, the target position for the welding line is preferably a position having an appropriate dimension from the end of the upper plate to the upper plate side. The place where 5 mm enters is good, and when the board thickness is 2.5 mm, the place where 0.8 mm enters is good. The required bead width increases as the plate thickness increases, and the plate thickness is 0.5 to 2.5.
In the range of 0.5 mm, it is desirable that as the sheet thickness increases, it is preferable to gradually set the position from 0.5 mm to the upper plate side from the end of the upper plate and gradually enter the upper plate side. It is necessary to adjust the torch approaching / separating operation in order to prevent a short circuit of the tungsten electrode 2 to the base material 1. The adjustment of the approaching / separating operation during welding of the electrode rotating TIG torch 12 is performed by the differential amplifier 16 by calculating the deviation between the arc voltage detection signal from the arc voltage detector 14 and the reference arc voltage from the arc voltage reference setter 17. , So that the deviation always becomes zero.
9 is performed by controlling the rotation of the approach / separation motor 21 to cause the electrode rotary TIG torch 12 to approach / separate. Therefore, the electrode rotating type TIG torch 12 can be controlled to a position at an appropriate distance with respect to the overlapping portion of the thin plates.

In the above embodiment, the target of the arc voltage integrated by the integrators 27a and 27b is 0 ° to 90 ° on the upper plate 1b side.
The angle range is 90 °, that is, 90 °.
The angle range θ2 is 90 ° which is 70 ° to 360 °, but the angle range θ1 is 175 ° which is 5 ° to 180 ° on the upper plate 1b side, and 180 ° to 355 ° on the lower plate 1a side.
Needless to say, even if the angle range θ2 of 175 ° is set, the center of the rotating circle of the arc can be controlled to be at an appropriate position with respect to the welding line in a plane parallel to the thin plate surface. In the above embodiment, two integrators 27a and 27b are used. However, one integrator integrates two detection signals within a predetermined angle range, and outputs two integrated values to the first comparator 28. In this case, if one of the detection signals in the predetermined angle range is integrated, the value is transferred to the other, the reset is performed at high speed, and the integration is performed on the detection signal in the other predetermined angle range, one integrator is sufficient. It is.

[0023]

As described above, according to the present invention, an electrode rotating type TIG is mounted on a thin portion having a thickness of 0.5 to 2.5 mm.
An electrode rotating TIG welding method for a thin plate to be welded,
The rotating diameter of the tungsten electrode provided on the welding torch in which the torch inclination angle is set within approximately ± 10 ° is within a range of 1 to 4 mm, and a circular motion having an appropriate rotating diameter is given according to the plate thickness. In addition, when an appropriate welding current is set according to the sheet thickness, and the arc generated at the tungsten electrode is rotated in one direction at a high speed, the lap welding is performed along the welding line of the overlapping portion of the thin plate, and the arc voltage is increased. Of the arc voltage, and the left and right sides of the arc voltage are determined on the basis of the front center in the traveling direction of the arc rotation circle parallel to the welding line of the thin plate overlap portion.
The difference between the respective integral values of the arc voltage waveforms at the rotational positions of the electrode in two predetermined angle ranges of not less than 180 ° and not more than 180 ° is determined, and the welding torch is moved in a direction perpendicular to the welding line in a plane parallel to the sheet surface. 0.5 to 0.8 mm on the upper plate side from the plate edge
The difference between the respective integral values of the arc voltage waveforms at the rotation positions of the electrodes in the two predetermined angle ranges when set at an appropriate position according to the plate thickness within the entered range is a reference value at the target position of the welding torch. The welding torch is orthogonal to the welding line in a plane parallel to the thin plate surface so that the difference between the integral value during welding and the reference value at the target position of the welding torch is compared so that the difference becomes zero. The welding torch at the proper position with respect to the welding line at the overlap of the thin plate by controlling the movement in the direction.
Automatic grooving of the weld line of the lap weld joint of thin plates becomes possible, the heat input of the welding arc is dispersed for various plate thicknesses, and wide and shallow penetration welds in the lap portion of thin plates are efficiently performed at high speed It can be formed well, and the reference value at the target position of the welding torch should be set to an appropriate position according to the plate thickness within a range of 0.5 to 0.8 mm from the upper plate end to the upper plate side. Accordingly, there is an effect that the target position of the arc is adjusted to an appropriate position corresponding to the plate thickness, and an appropriate bead shape required by the welded portion can be maintained.

[Brief description of the drawings]

FIG. 1 is a thin-plate electrode rotating TI according to one embodiment of the present invention.
It is a lineblock diagram showing the whole electrode rotation type TIG welding device used for the G welding method.

FIG. 2 shows an electrode rotation TIG of the electrode rotation type TIG welding apparatus.
It is sectional drawing which shows a torch.

FIG. 3 is an explanatory diagram showing a torch inclination angle of an electrode rotary type TIG torch.

FIG. 4 is a schematic diagram showing a scanning signal detection method of the groove line scanning method.

FIG. 5 is an explanatory diagram showing a difference in a bead shape depending on a target position.

[Explanation of symbols]

 1 Base Material 2 Tungsten Electrode 11 Rotational Position Detector 12 Electrode Rotary TIG Torch 14 Arc Voltage Detector 22 Lateral Movement Mechanism Controller (Drive Control Unit) 23 Torch Lateral Movement Mechanism 24 Lateral Movement Motor 24 26 Timing Circuit 27a Integrator 27b Integrator 28 First comparator 29 Torch position target position setting device 30 Second comparator 31 Welding line scanning control circuit (drive control unit)

Continuation of the front page (56) References JP-A-6-312263 (JP, A) JP-A-1-148465 (JP, A) JP-A-1-91966 (JP, A) JP-A-62-279086 (JP) , A) (58) Field surveyed (Int. Cl. ⁶ , DB name) B23K 9/127 B23K 9/02 B23K 9/167

Claims (1)

(57) [Claims] 1. A stack of thin plates having a thickness of 0.5 to 2.5 mm.
Rotating electrode TI of thin plate that performs electrode rotating TIG welding on the part
In a G welding method, a rotating diameter of a tungsten electrode provided on a welding torch whose torch inclination angle is set within approximately ± 10 ° within a rotation diameter of 1 to 4 mm and an appropriate rotation according to a plate thickness. Of diameter
Gives circular motion and sets appropriate welding current according to plate thickness
An arc voltage is detected during welding in which lap welding is performed along a welding line at a lap portion of a thin plate while rotating an arc generated in the tungsten electrode in one direction at a high speed, and among the arc voltages, an arc voltage of the thin plate is detected. 5 on the left and right of the center of the arc in the traveling direction of the arc of rotation parallel to the welding line of the overlapped portion.
Determines the difference between each of the integral value of the arc voltage waveform at the rotational position of ° or more than 180 ° of the two predetermined angular range of the electrodes, the welding torch in the direction perpendicular to the weld line in a plane parallel to sheet surface, the upper 0.5 to 0.8 mm on the upper plate side from the plate edge
The difference between the respective integral values of the arc voltage waveforms at the rotation positions of the electrodes in the two predetermined angle ranges when set at an appropriate position according to the plate thickness within the entered range is a reference value at the target position of the welding torch. The difference between the integral value during welding and the reference value at the target position of the welding torch is compared, and the welding torch is orthogonal to the welding line in a plane parallel to the thin plate surface so that the difference becomes zero. A TIG welding method for a thin plate electrode, wherein the welding torch is controlled to an appropriate position with respect to a welding line of a lap portion of the thin plate by controlling movement in a direction in which the thin plate is overlapped.