JPH0825036A - Method for welding fixed pipe and welding device therefor - Google Patents

Abstract

PURPOSE:To attain the connection of pipes having uniform penetration bead even by the general inert gas welding of an MAG welding, etc., by allowing a torch at the time of welding to face the direction where molten metal flows out by gravity and allowing the welding arc vector to deflect in the direction where it acts to push up the molten metal. CONSTITUTION:A welding module travelling table 22 turns around the outer peripheral side of the pipes 1, 2 accompanying the rotation of a gear engaged with a gear 21 for tracking. A swing center shifting table 23 arranged on the welding module travelling table 22 is shifted to the diameter direction of the gear 21 for tracking to adjust the relative position between the torch 11 and the welding part. Further, a torch turning member 24 arranged on the swing center shifting table 23 is turned around the swing center, and the relative position and the torch inclining angle to the welding part are decided with the necessary position and torch angle to prevent the flow-out of the molten metal to weld the pipes 1, 2. Therefore, the welding arc vector of the torch 11 is deflected in the direction, in which the molten metal does not flow out, and the welding can be progressed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for welding a fixed pipe and a welding apparatus for the same so as to uniformly generate a back wave generated in the welding of the first layer during welding of the pipe.

[0002]

2. Description of the Related Art Conventionally, when welding pipes, as shown in FIG. 6, a welding torch (indicated by an arrow) 3 is attached to two pipes 1 and 2 at a predetermined constant angle θ (= 0 to 10).
Welding is performed by moving the entire circumference (360 °) of the swing center orbit 4 of the welding torch 3 or by moving a half circumference (180 °) of the swing center orbit 4 twice.

For this reason, in the weld metal on the pipe, the flow direction of the molten metal is the same as the direction of gravity depending on the welding location, so that more molten metal flows out at that location. The back waves 5 projecting from the pipe back sides (pipe inner surfaces) 1a and 2a shown in Fig. 2 differ depending on the circumferential position and become non-uniform.

Since such a phenomenon is likely to occur when general inert gas welding (MAG, Co ₂ welding, etc.) is used, it is performed by TIG welding which can obtain good results even in such a state. . This TIG welding is inefficient because the welding time is long, but it is less uneven than using MAG, CO ₂ welding, etc., and is now the best method for welding fixed pipes. .

[0005]

In the above-mentioned conventional technique, TIG welding is used to weld a fixed pipe, but there is a problem that the welding time becomes long and inefficient. .

The present invention was devised in view of the above-mentioned current situation, and the object is to use MAG, CO
_{(2) The} object of the present invention is to provide a welding method for a fixed pipe and a welding device for the same, in which the back wave is uniform even by general inert gas welding such as ₂ welding and the pipe connection can be performed efficiently.

[0007]

In order to achieve the above object, according to the present invention, the direction of the torch during welding is opposed to the direction in which the molten metal flows out by gravity, and the welding arc vector is It is characterized in that the fixed pipe is welded by deflecting the molten metal so as to act so as to push it up.

As a welding device for realizing this method, an automatic welding device for automatically welding while moving the torch along a groove provided in a welded portion of a fixed pipe is coaxial with the pipe. A orbital gear for forming a swing center orbit, a welding module carriage that circulates on the outer peripheral side of a pipe, and a gear that meshes with the orbital gear; and a radial direction of the orbital gear on the welding module carriage. The swing center moving table installed movably, and the torch rotating member detachable from the torch installed on the swing center moving table so as to be rotatable around the swing center. .

Further, as a welding apparatus for realizing the above method, an automatic welding apparatus for automatically welding while moving a torch along a groove provided in a welded portion of a fixed pipe is used. From the relative position of the torch, the torch tilt angle, and the tracking data, a calculation unit that determines the state of the torch with respect to the weld, a welding position calculation determination unit that determines a new welding position based on the output data of the calculation unit, and the calculation unit Based on the output data of the torch, adjust the torch position and the torch tilt angle by moving the torch close to and away from the weld and rotating it around the swing center, and based on the relative position of the torch with respect to the weld and the torch tilt angle. And a welding condition setting unit that obtains and outputs welding conditions.

[0010]

Therefore, in the present invention, when the above method is applied, the torch is moved along the swing center orbit with respect to both pipes to be welded, and the position and orientation of the torch are always kept in the molten metal. The torch tip is directed in the same direction, and the welding arc vector is adjusted so that it acts in a direction to push back the molten metal flowing out.

Then, the torch is rotated with respect to the swing center so as to have an optimum torch angle θ _T (see FIG. 2) determined by each welding position, and melted along the groove formed in the pipe weld. Even if the metal flows out and falls due to gravity, the component force P _T according to the torch angle θ _T generated from the combined force (welding arc vector) P of the arc and gas force of the inert gas welding (see FIG. 2) (Fig. 2) acts as a push-back force P _T of a necessary magnitude in the tangential direction of the welded portion to hold down the molten metal that is about to flow out, solidify the molten metal, and hold it in a position where it should be stacked.

Further, by using the welding device according to claim 2 for welding the fixed pipe, the welding module carriage orbits the outer peripheral side of the pipe in accordance with the rotation of the gear meshing with the orbital gear, and the welding module carriage is moved. The swing center moving table installed on the table moves in the radial direction of the orbital gear to adjust the relative position of the torch and the welded portion,
By rotating the torch rotation member installed on the swing center moving table around the swing center, the relative position with respect to the weld and the torch tilt angle are always the position and torch angle required to prevent the molten metal from flowing out. Weld the pipe by.

Furthermore, in the welding device according to the third aspect of the present invention for welding the fixed pipe, when automatically welding while moving the torch along the groove provided in the welded portion of the fixed pipe, The calculation unit calculates the torch state relative to the weld by inputting the relative position of the torch to the weld, the torch tilt angle, and the tracking data, and the adjustment unit moves the torch closer to and away from the weld based on the output data from the calculator. In addition, the torch position and torch tilt angle are adjusted by rotating around the swing center so that the pipe can be welded at the position and torch angle required to prevent the outflow of molten metal. By welding according to the welding conditions determined based on the relative position of the torch with respect to the torch and the tilt angle of the torch. The outflow of prevention, welding bumps having a predetermined uniform penetration can be realized. Then, the welding position calculation determination unit determines a new welding position based on the output data of the calculation unit, and sequentially welds the entire circumference of the pipe.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described in detail below with reference to an embodiment shown in the accompanying drawings.

[Structure of Embodiment] FIG. 3 is a diagram showing details of the position change in this embodiment.

In FIG. 3, the torch positions are from T1 to T2.
In order to make the distances from the pipes 1 and 2 at the tip of the torch the same, the torch rotation center 13 is moved to the pipe side from the swing center trajectory 4 by the distance l _{1 at the} position T1, and the torch angle is changed. With respect to the horizontal position θ ₁
Rotate to tilt only.

Similarly, at the T2 position, the torch rotation center 13 is moved toward the pipe side by a distance l ₂ from the swing center trajectory 4, and is rotated so that the torch angle is inclined by θ _{2 with} respect to the horizontal position.

In this way, the torch rotation center 13 of the torch 11 with respect to the pipes 1 and 2 is moved from the swing center orbit 4 to the pipes 1 and 2 side while the swing center orbit 4 is rotated around the entire circumference or the half circumference twice. The torch 11 is rotated around the torch rotation center 13 while being moved toward and away from the torch 11.

In the structure for performing such an operation, the direction in which the torch rotation center 13 of the torch 11 is moved toward and away from the swing center track 4 toward the pipes 1 and 2 is A.
Axis, the torch rotation center axis is abbreviated as B axis, and the center axis of the swing center trajectory 4 is abbreviated as C axis.
It serves as a central axis of a swing center orbit gear (hereinafter, abbreviated as C-axis gear) 21 provided coaxially with No. 2. C-axis gear 2
1 is provided with a gear (not shown) that meshes with C.
Welding module carriage 22 that orbits the outer circumference of the pipe along
Is installed, and the A-axis direction moving member 23 slidable in the A-axis direction is installed on the welding module carriage 22 as a swing center moving table. The torch 12 is installed around the B-axis around the A-axis direction moving member 23. The B-axis rotating member 24 to be rotated is attached as a torch rotating member, and the torch 11 is detachably fixed to the B-axis rotating member 24.

The movement of the torch 11 thus installed is computer controlled. This computer controller
As shown in FIG. 5, the torch 11 is determined from the position of the welding module carriage 22 in the C-axis gear 21, the position of the A-axis direction moving member 23 in the welding module carriage 22, and the rotation angle of the B-axis rotating member 24. Torch 11 necessary for the welding position that has been set as well as the position and orientation of the welding tool have been calculated and stored.
Position / orientation data unit 31 for indexing and storing the position and orientation, a tracking data unit 32 for indexing and storing the position of the welding module carriage 22 for moving the C-axis gear 21, a torch position / attitude data unit 31, and tracking Arithmetic unit 3 for arithmetically processing data from the data unit 32
3 and the A-axis direction moving member 2 based on the data of the calculation unit 33.
A for correcting the position of 3 and the rotation angle of the B-axis rotating member 24
Axis B-axis adjustment unit 34 and welding position calculation determination unit 35 that calculates a position to be newly welded based on the data of the calculation unit 33.
And a welding condition setting unit 36 that sets welding conditions based on the data of the torch position and orientation data unit 31.

[Operation of Embodiment] In the embodiment thus constructed, the torch 11 moves from the uppermost position (0 ° position) to the lowermost position (180 ° position) of the welding positions of the pipes 1 and 2. During the change, the orientation changes as shown in FIG.

For example, at the start position (position of 0 °), the angle between the axial direction of the torch 11 and the horizontal line is a counterclockwise tilt angle in the range of 0 to 15 ° with the torch tip side facing downward. When the torch angle was changed from this state to the intermediate position (90 ° position) where the welding torch vector was changed upward in this state, the axis of the torch 11 was turned upward with the torch tip side facing upward. The angle between the direction and the vertical line is a torch angle that forms a tilt angle in the range of 0 to 30 ° in the counterclockwise direction, and the welding torch vector is changed in direction while keeping the upward direction, and the position is a quarter turn ( 180 °
Position), the direction is opposite to the direction of the start position, and the torch tip side is facing up.
The angle between the horizontal axis and the axial direction of is 0 to 30 in the counterclockwise direction.
It is a torch angle with an inclination angle in the range of °.

When the welding is started, the movement of the torch 11 is controlled by the computer controller in synchronization with the progress of the welding.

When welding is started, the calculation unit 33 reads out data from the torch position / posture data unit 31 and the tracking data unit 32 to perform calculation, knows the position of the torch 11 at that time, and when the position is known, the torch at the angle θ is obtained. The attitude data is known, and the stroke with respect to the A-axis and the angle with respect to the B-axis are known by calculating from this data. Based on the stroke and the angle thus obtained, the A-axis / B-axis adjusting unit 34 corrects the position of the A-axis direction moving member 23 and the rotation angle of the B-axis rotating member 24. At the same time, the welding conditions in the position and orientation at this time are output from the welding condition setting unit 36 to proceed with welding.

While circling the outer circumferences of the pipes 1 and 2 according to the C-axis gear 21 in this order, the radial direction of the C-axis gear 21 is adjusted by the A-axis direction moving member 23, and B is adjusted.
By adjusting the torch angle around the B axis by rotating the shaft rotating member 24, the pipes 1 and 2 are welded without causing the molten metal 12 to flow out from a predetermined welding location.

[Effects of the Embodiment] As described above, in the embodiment,
By allowing the torch 11 to constantly deflect the welding arc vector so that the molten metal does not flow out so that the welding can proceed, when welding the fixed pipes 1 and 2, MAG, CO ₂ gas, etc. It can be carried out efficiently even by general inert gas welding using, and the back waves generated on the back surface of the pipe are made uniform, shortening the welding time,
The cost can be reduced.

[0027]

As described above, according to the method for welding a fixed pipe of the present invention, since the welding arc vector acts in the direction of pushing up the molten metal, the molten metal is prevented from flowing out and the bead is uniform. Will be deposited on the
Even with general inert gas welding using MAG, CO ₂ gas, etc., the back waves formed on the back side of the pipe are made uniform, the welding quality can be improved, the welding time can be shortened, and the cost can be reduced. be able to.

Further, in the welding apparatus for welding a fixed pipe of the present invention, the welding module carriage orbits the outer peripheral side of the pipe in accordance with the rotation of the gear meshing with the orbital gear, and is installed on the welding module carriage. The swing center moving base moves in the radial direction of the orbital gear to adjust the relative position of the torch and the welded portion, and the torch rotating member installed on the swing center moving base is rotated around the swing center. The relative position and the torch tilt angle with respect to the welded portion are always fixed to the outer circumference of both fixed pipes by welding the pipes at the position and torch angle required to prevent the outflow of molten metal. Until the molten metal piled up solidifies and the outflow does not occur, the welding arc vector prevents the outflow in the falling direction, resulting in a beautiful weld with uniform backwaters. It can be current.

Furthermore, in the welding device for welding a fixed pipe according to the present invention, when automatically welding while moving the torch along the groove provided in the welded portion of the fixed pipe, The calculation unit finds the torch state relative to the welded portion relative to the input welded portion, the torch tilt angle, and tracking data, and the adjustment unit moves the torch closer to the welded portion based on the output data from the calculation unit. The torch position and the torch tilt angle are adjusted by separating and rotating around the swing center so that the pipe can be welded at the position and torch angle necessary to prevent the outflow of molten metal. Welding by welding in accordance with the welding conditions determined based on the relative position of the torch with respect to the welded part and the torch tilt angle. Outflow of the metal is prevented, welding bumps having a predetermined uniform penetration can be realized.

Then, the welding position calculation determination unit determines a new welding position based on the output data of the calculation unit, and sequentially welds the entire circumference of the pipe, so that the molten metal is constantly pressed by the torch. It can be adjusted so that the welding arc vector acts in the direction, and the welding of the outer circumference of the pipe can have a beautiful weld portion that causes uniform backside.

[Brief description of drawings]

FIG. 1 is an explanatory view showing movement of a torch with respect to a pipe in the method of the present invention.

FIG. 2 is a conceptual explanatory view showing a relationship between a molten metal and a torch vector according to the method of the present invention.

FIG. 3 is a partially enlarged explanatory view showing movement of the torch with respect to the pipe in the embodiment of the present invention.

FIG. 4 is a front view showing a welding device according to an embodiment of the present invention.

FIG. 5 is a block diagram showing a control unit of the welding apparatus.

FIG. 6 is a conceptual explanatory view showing a conventional pipe welding method.

FIG. 7 is a partially enlarged sectional view showing a first layer of welding in conventional welding.

[Explanation of symbols]

 1, 2 Pipes 1a, 2b Pipe backside (inner surface of pipe) 3 Torch 4 Torch swing center orbit 5 Back wave 11 Torch 12 Molten metal 13 Torch rotation center 21 Swing center orbit gear (C axis gear) 22 Welding module carrier 23 A-axis direction moving member 24 B-axis rotating member 31 Torch position / posture data 32 Tracking data section 33 Computing section 34 A-axis B-axis adjusting section 35 Welding position calculation determining section 36 Welding condition setting section

Claims (3)

[Claims] 1. A fixing method, characterized in that the direction of a torch during welding is opposed to a direction in which molten metal flows out by gravity, and the welding arc vector is deflected so as to act in a direction to push up the molten metal. Welding method for finished pipes. 2. An orbit for forming a swing center orbit provided coaxially with a pipe in an automatic welding device for automatically welding while moving a torch along a groove provided in a welded portion of a fixed pipe. A gear, a welding module carriage that orbits the outer peripheral side of the pipe and includes a gear that meshes with the orbital gear, and a swing center moving base installed on the welding module carriage so as to be movable in the radial direction of the orbital gear. ,
A fixed pipe welding device, comprising: a torch rotating member that is detachably attached to the swing center moving base so as to be rotatable around the swing center. 3. An automatic welding apparatus for automatically welding while moving a torch along a groove provided in a welded portion of a fixed pipe, a relative position of the torch with respect to the welded portion, a torch inclination angle, and tracking data. From the calculation unit, a welding position calculation determination unit that determines a new welding position based on output data of the calculation unit, and a torch for the welding unit based on output data from the calculation unit. Of the torch position and the tilt angle of the torch by rotating them around the swing center and the welding condition setting unit that calculates and outputs the welding conditions based on the relative position of the torch and the torch tilt angle. A fixed pipe welding device characterized by having and.