JP3348351B2 - Laser welding method and equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a laser welding method and apparatus for welding a peripheral joint of a steel pipe such as a pipeline or a gas pipe using a laser beam capable of guiding light with an optical fiber. Belongs to.

[0002]

2. Description of the Related Art Conventionally, in a welding method for a pipeline or the like, as shown in, for example, FIG. There is a so-called manual welding multi-layer welding method in which beat welding 1 is performed, hot-pass welding 2 is performed, and filler welding 3 is performed last.

[0003] Among other welding methods, a welding device mounted on a ring-shaped rail is set on the outer periphery of a peripheral joint of a pipe at a groove position, and the same procedure as the above-mentioned manual welding is performed by using the welding device. There is a multilayer build-up welding method by so-called semi-automatic welding, which welds from the outer surface.

[0004] However, in the case of manual welding, although welding is simple, all operations are manual, which requires time and effort. In addition, there is a large artificial difference in construction depending on the skill level, and the welding quality is significantly reduced. May be invited. On the other hand, in the case of semi-automatic welding, since it is semi-automatic, the work of welding work is somewhat improved accordingly, but it takes time to accurately set the welding device to the groove position, and it still takes time to work. .

[0005] Further, whether manual welding or semi-automatic welding is used, multi-pass welding is required, so that the number of passes is considerably large and the arc time is long, resulting in low productivity. Further, in each case, welding materials such as a welding rod and a welding wire are separately required, and there is a problem that a complicated slag removal operation is required for each bead.

Therefore, in the conventional welding method, the welding material is not used, and the base material is melted by using a laser beam.
A laser welding method for welding the entire circumference of a groove with a pass has been proposed. For example, a truck is set on a ring-shaped rail outside the pipe joint at the groove position, the laser welding head mounted on the truck is rotated together with the truck, and a laser beam is irradiated on the groove to weld the entire circumference of the groove. There is something to do.

[0007]

[Problems to be Solved by the Invention] In the laser welding method, although a molten material may be supplied, in principle, the base material is melted and welded. The butt appearance of the groove becomes a thin line and is one-pass welding, so that strict positional accuracy of the target position of the laser beam with respect to the entire circumference of the groove is required. However, in the conventional laser welding method described above, the reference position of the target position is set linearly over the entire circumference of the groove from the outside of the pipe. It is extremely difficult to accurately determine the linear target position reference.In practice, there is a problem that the target position with respect to the groove of the laser beam is likely to be shifted, which may result in a decrease in welding quality. there were.

Accordingly, an object of the present invention is to solve the conventional problems in the above-described method and apparatus for laser welding steel pipes, and to provide a welding groove without impairing the advantages of one-pass welding using a laser beam. The purpose of the present invention is to improve the position accuracy of the target position of the laser beam with respect to the welding to improve the welding quality.

[0009]

The object of the present invention is to provide a laser welding method for welding a peripheral joint of a steel pipe using a laser beam capable of guiding light with an optical fiber, wherein a laser welding means inserted into the steel pipe is mounted. The welding trolley is run and stopped at approximately the butt position of the steel pipe after skin matching, and the laser welding means can be rotated around the pipe axis of the steel pipe and in the pipe axis direction.
The rotation center line of the rotating support that is integrally erected so that it can move to the center of the steel pipe is fixed substantially in line with the central axis of the steel pipe, and the rotating support is rotated to make the steel pipe with a sensing device mounted on the rotating support. The welding groove position is detected, the welding groove position for each welding position is calculated based on the detection result, and the laser welding means is rotated until the rotation center reaches the calculated welding start position. After adjusting the movement along the center line, the one-dimensional control is performed so that the laser welding means moves along the rotation center line of the rotating support in accordance with the rotation of the rotating support using the calculation data of the welding groove position. This is achieved by rotating the rotary support and irradiating the welding groove position with laser light by laser welding means to perform welding.

[0010] The object of the present invention is to provide a laser welding method according to claim 1, wherein after the laser welding means is moved and adjusted along the rotation center line of the rotary support, the focal point of the laser beam is focused on the welding portion. In addition to controlling the position of the steel pipe in the radial direction so that it hits correctly, the laser welding means is moved along the rotation center line of the rotary support in accordance with the rotation of the rotary support using the calculation data of the welding groove position. This is achieved by rotating the rotary support and irradiating a laser beam to the welding groove position by laser welding means while performing one-dimensional control to perform welding.

An object of the present invention is to provide a laser welding apparatus for welding a peripheral joint of a steel pipe by using a laser beam capable of guiding light with an optical fiber. After that, a welding cart that stops at the approximate butt position, a rotating support body integrally erected so that the laser welding means can rotate and can move in the pipe axis direction, and a rotation center line of the rotating support body A fixing means for fixing the rotating support in the radial direction of the steel pipe so as to substantially coincide with the center axis of the steel pipe, and mounting on the rotating support to detect the welding groove position of the steel pipe when rotating the rotating support during welding work Calculating the welding groove position based on the detection result of the sensing device, the linear moving means for moving the laser welding means along the rotation center line of the rotating support in the steel pipe, and the detection result by the sensing device. After controlling the operation of the linear moving means to move the laser welding means to a position where the rotation center of the laser welding means reaches the calculated welding groove position, the rotation support is rotated using the calculated data of the welding groove position. Control means for controlling the rotation driving means to rotate the rotating support while controlling the laser welding means in one-dimensional manner so that the laser welding means moves along the rotation center line of the rotating support is achieved.

[0012] The object of the present invention is to provide a laser welding apparatus according to claim 3, wherein the laser welding means rotates the laser welding means so as to be position-controllable in the radial direction of the steel pipe so that the focal point of the laser beam is correctly focused on the welding part. This is achieved by standing upright on the support.

An object of the present invention is to provide a laser welding method for welding a peripheral joint of a steel pipe using a laser beam capable of guiding light with an optical fiber. After stopping at approximately the abutting position of the steel pipe after the joining, the laser welding means is rotated so as to be rotatable about the pipe axis of the steel pipe and movable in the pipe axis direction.
The rotation center line of the rotating support erected on the body is fixed substantially in line with the central axis of the steel pipe, the welding device of the steel pipe is detected by the sensing device mounted on the rotating support, and the laser welding means is provided. After adjusting the movement along the rotation center line of the rotation support until the rotation center reaches the welding start position,
When rotating the rotating support, the laser welding means moves along the rotation center line of the rotating support according to the rotation of the rotating support by using the data while detecting the welding groove position. This is achieved by irradiating a laser beam to a welding groove position by laser welding means while performing control and performing welding.

The object of the present invention is to provide a laser welding method according to claim 5, wherein after the laser welding means is moved and adjusted along the rotation center line of the rotary support, the focal point of the laser beam is focused on the welding portion. In addition to controlling the position in the radial direction of the steel pipe so that it hits correctly, when rotating the rotating support, while detecting the welding groove position, the laser welding means uses the data to match the rotation of the rotating support and This is achieved by irradiating a laser beam to a welding groove position by laser welding means while performing one-dimensional control so as to move along the rotation center line of the rotating support, thereby performing welding.

An object of the present invention is to provide a laser welding apparatus for welding a peripheral joint of a steel pipe by using a laser beam capable of guiding light with an optical fiber. After that, a welding bogie that stops at the substantially abutting position, a rotating support that is integrally erected so that the laser welding means can rotate and can move in the pipe axis direction, and a rotation center line of the rotating support is Fixing means for fixing the rotating support in the radial direction of the steel pipe so that it substantially coincides with the central axis, and mounting on the rotating support to detect the welding groove position of the steel pipe when rotating the rotating support during welding Controlling the operation of the linear moving means based on the sensing device to perform, the linear moving means for moving the laser welding means along the central axis in the steel pipe, and the detection result by the sensing device. After the user welding means has moved to the welding start position, the rotation support means is rotated by controlling the rotation driving means, and at the time of rotation of the rotation support, the rotation is performed using the data while detecting the welding groove position. Control means for one-dimensionally controlling the movement of the support in the direction of the rotation center line.

The above object is achieved by the laser welding apparatus according to claim 7, wherein the laser welding means is capable of controlling the position of the laser beam in the radial direction of the steel pipe so that the laser beam can be properly focused on a welding portion. This is achieved by standing upright on the support.

[0017]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 2 shows an outline of a laser welding apparatus according to the present invention. In the drawing, reference numeral 10 denotes a steel pipe 1 after skin fitting.
1 is a welding cart of a laser welding apparatus according to the present invention, which is inserted and arranged in 1, 1; The welding trolley 10 includes a first trolley 13 having a drive wheel 12 pivotally supported on the outer periphery thereof, and a second trolley 15 having a driven wheel 14 pivotally supported on the outer periphery thereof. The bogies 13 and 15 are connected by a rotary support 16, and the rotary support 16 is supported via a bearing 17 so as to be rotatable around the pipe axis of the steel pipes 11 and 11 about a rotation center line O. The configuration is as follows.

The first bogie 13 has a second
A rotation drive motor (rotation drive means) 18 is attached so as to protrude toward the cart 15. The first bogie 13 and the second bogie 15 are provided with a tension mechanism 19 having a structure that expands and contracts in the radial direction on the sides facing each other on the outer periphery, with an interval of a screening angle of, for example, 120 degrees in the outer periphery. It is attached to open.

The rotary support 16 has a substantially cylindrical shape, the central portion of which is formed to have a larger diameter by one step, and is accommodated inside the large diameter portion 16a to support the welding mechanism mounting frame 20. The large-diameter portion 16a is provided with an opening 16b on the upper side for exposing the welding mechanism mounting frame 20 to the outside, and a tooth portion 16 meshing with the motor gear 18a of the rotary drive motor 18 is provided on the outer periphery of the left edge in the figure.
c is provided.

As shown in FIGS. 3 and 4, the welding mechanism mounting frame 20 includes a welding mechanism indicated by reference numeral 21 in the figure. The welding mechanism 21 has a laser welding nozzle (laser welding means) 23 mounted on a nozzle mounting base 22 containing a welding operation part and the like. Then, the nozzle mounting base 22 is mounted on the bottom of the welding mechanism mounting frame 20 on an LM guide 25 provided in parallel with the rotation center line O of the rotary support 16, and connected to the LM guide 25. Do it. The entire LM guide 25 is protected by a long cylindrical bellows 25a. The position of the laser welding nozzle 23 is controlled in the radial direction of the steel pipe 11 so that the focal point of the laser beam is correctly applied to the welding site.

An optical fiber and a control / power cable 24 are connected to the laser welding nozzle 23. As a laser used for welding with the laser welding nozzle 23, a so-called YAG laser or iodine laser capable of guiding light with an optical fiber is preferable.

As shown in FIG. 3, a nozzle mounting base 22 is provided on the upper side of the welding mechanism mounting frame 20.
Is linearly moved integrally with the laser welding nozzle 23.

The linear moving means 26 has a servomotor 27 mounted on the upper left side of the welding mechanism mounting frame 20, and has a motor shaft of the servomotor 27 connected to a feed shaft 29 via a rotation transmitting coupling 28a and a servo unit 28b. One end is connected. The other end of the feed shaft 29 is supported on the upper right side of the welding mechanism mounting frame 20 via an angular ball bearing 30. The nozzle mounting base 22 is connected via a ball screw 31 that engages with the feed shaft 29.

The rotating support 16 described above is equipped with a sensing device, described later, for detecting the welding groove position of the steel pipes 11, 11 when the rotating support 16 is rotated during welding, which will be described later. As the sensing device, an optical detection type, a mechanical detection type, and the like can be considered.

Although not shown, the illustrated laser welding apparatus includes a mobile vehicle equipped with a power supply, a laser light oscillator, a cooling system supply unit, a control panel (control unit), and the like. The entire operation can be controlled by the control panel.

For example, the bearing 17 and the servo unit 28 used in the illustrated laser welding apparatus are used.
b, the ball screw 31 and the like are configured to have a preload structure so as to absorb backlash and mounting errors.

Next, a method of welding the steel pipes 11 and 11 using the laser welding apparatus having the above-described configuration will be described.

In laser welding, the steel pipes 11, 11
The root gap of the welding groove is desirably, for example, 0.2 mm or less. However, after the steel pipes 11 and 11 are skinned, the welding carriage 10 is put in the steel pipes 11 and arranged. Then, as shown in FIG.
For example, the operator detects using a CCD camera or the like and stops at approximately the butting position of the steel pipes 11 (for example, within a range of about 25 mm before and after the butting position).

Next, the tension mechanism 19 is actuated, and as shown in FIG.
Are substantially coincident with the central axes of the steel pipes 11, 11, and the welding cart 10 is fixed at the stop position.

Thereafter, the rotary support 16 is rotated by the rotary drive motor 18, and as shown in FIG. 1C, the welding groove position P of the steel pipes 11, 11 is detected by the sensing device 35. The welding groove position P is calculated based on the welding groove position P.

Then, the servo motor 27 of the linear moving means 26 is operated to rotate the feed shaft 29, and the nozzle mounting base 22 is linearly moved integrally with the laser welding nozzle 23,
As shown in FIG. 1D, the rotation center A of the laser welding nozzle 23 is moved and adjusted in the direction of the rotation center line O to a position reaching the calculated welding groove position P.

Then, using the calculated data of the welding groove position, the position of the laser welding means is controlled one-dimensionally along the rotation center line O of the rotary support 16 as shown in FIGS. Then, the rotary support 16 is rotated, and a laser beam is irradiated from the laser welding nozzle 23 to the welding groove position to perform welding. At this time, the position of the laser welding nozzle 23 is controlled in the radial direction of the steel pipe 11 so that the focal point of the laser beam is correctly applied to the welding part.

In the strict sense, the circumferential joint of the steel pipes 11, that is, the groove surface, is seldom perpendicular to the rotation center line O of the rotary support 16 in practice. It does not always completely coincide with the central axis of the steel pipes 11,11. Therefore, as shown in FIG. 5, when the rotation center of the laser welding nozzle 23 is at the point B shifted from the welding groove position, and the laser beam and the groove position are not parallel, welding is performed around the point B. In this case, the inclination angle of the laser welding nozzle 23 is complicated at the rotation angle position, and the control of the laser beam becomes two-dimensional or more. As a result, the target position with respect to the groove of the laser beam is shifted and the welding quality may be deteriorated.

However, in the present invention, the laser welding nozzle 23 is fixed while the angle of the laser welding nozzle 23 is fixed with respect to the rotation center line O of the rotating support 16 substantially coinciding with the steel pipe axis.
When the laser beam is moved and adjusted to the point A along the rotation center line O according to the rotation angle so that the laser beam of the laser beam comes to the point A of the welding groove position. The laser beam at a right angle or a fixed angle to the rotation center line O is one-dimensionally controlled in the direction of the rotation center line O substantially coincident with the center axis of the steel pipes 11, 11, so that the welding groove position can be accurately detected. it can.

In the above-described embodiment, the welding is performed by rotating the rotary support 16 once each time the detecting operation of the groove position by the sensing device 35 and the laser irradiation welding operation by the laser welding nozzle 23 are performed. Was. However, the present invention can also be configured to perform groove detection and laser irradiation welding with one rotation of the rotary support 16.

Also in this case, welding is performed using a laser welding apparatus having the same structure as the laser welding apparatus in the above embodiment. Then, at the time of laser welding, after adjusting the movement of the laser welding nozzle 23 as a laser welding means to a position where the rotation center A reaches the welding start position,
In particular, when the rotary support 16 is rotated, the position of the laser welding means is controlled by the control means using the data while the welding groove position is detected by the sensing device 35 in the direction of the line center line O of the rotary support 16. The laser welding nozzle 23 irradiates a laser beam to the welding groove position while performing one-dimensional control to perform welding.

That is, when the rotary support 16 makes one rotation, the detection of the welding groove position is started immediately before the irradiation of the laser beam, and the welding groove position is detected immediately after detecting the groove position in real time. Controls to perform welding by irradiating the position with a laser beam. In addition, similarly, the position of the laser welding nozzle 23 is controlled in the radial direction of the steel pipe 11 so that the focus of the laser beam is correctly applied to the welding part.

[0039]

According to the present invention configured as described above, the following effects can be obtained.

According to the laser welding method and apparatus of the present invention, the groove position is detected by being installed in a steel pipe and rotating from the inside with the rotation center line of the rotary support of the laser welding means as the sole rotation reference. Then, based on the detection result, the target position of the laser beam with respect to the entire circumference of the groove is set based on the point of the center of rotation of the laser welding means, so that the ring-shaped rail from the outside of the steel pipe as in the past Unlike the case of performing automatic welding with a welding groove as a reference, the target position of the laser beam with respect to the groove is less likely to shift, and the rigorous setting of the target position of the laser beam with respect to the welding groove at the welding site is greatly facilitated. Therefore, the accuracy of the target position can be improved to improve the welding quality.

Further, the rotary support mounted on the welding carriage is fixed so that the rotation center line of the rotary support substantially coincides with the central axis of the steel pipe, and the rotation center of the laser welding means is adjusted to the welding groove position calculated in advance. By adjusting the movement of the laser welding means to the position up to, while using the calculation data of the welding groove position, only one-dimensional control of the movement of the rotating support in the direction of the rotation center line is performed and welding is performed. The target position of the laser beam is matched to the welding groove without error by following the groove shape, thereby minimizing the mechanical error factor during on-site welding and improving the welding quality.

Of course, the present invention is a laser welding method and apparatus for welding using a laser capable of guiding light with an optical fiber, so that there is no great difference in the work depending on the skill level. In addition, since it is one-pass welding on a flat groove (I groove) peculiar to beam welding such as laser welding instead of multi-layer welding as in the conventional case, the arc time can be remarkably reduced and the productivity can be increased. . Furthermore, since welding can be performed by melting into the base material, it is possible to eliminate the need for a welding material, and it is possible to simplify quality control without troublesome slag removal work.

In addition, according to the laser welding method and apparatus according to the fifth and seventh aspects, when the rotating support is rotated, the detection of the welding groove position is started immediately before the irradiation of the laser beam, While detecting the groove position, immediately irradiate the laser beam to the welding groove position and perform the groove detection and laser welding with one rotation of the rotating support, so the construction time is shortened accordingly Efficiency can be increased.

In addition, claims 2, 4, 6, and 8
According to the method and apparatus for laser welding, the position of the laser welding means is controlled in the radial direction of the steel pipe so that the focus of the laser beam is correctly focused on the welding area, thereby further improving welding accuracy Can be done.

[Brief description of the drawings]

FIG. 1 is a process explanatory view showing a construction process of a laser welding construction method performed by using a laser welding construction device according to the present invention.

FIG. 2 is a schematic vertical sectional view showing a laser welding apparatus according to the present invention disposed at a welding groove position in a steel pipe.

FIG. 3 is a schematic longitudinal sectional view showing a welding mechanism mounted on a welding mechanism mounting frame of the laser welding apparatus.

FIG. 4 is a schematic configuration diagram showing the welding mechanism as viewed from the front side.

FIG. 5 is an explanatory diagram illustrating a one-dimensional control state of a rotation center line of a rotary support at a welding groove position.

FIG. 6 is an explanatory diagram for comparing and explaining position adjustment control when the rotation center of the laser welding nozzle is at a welding groove position and at a position shifted therefrom.

FIG. 7 is a state explanatory view showing a multi-layer welding state performed without using conventional laser welding.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Welding trolley 11 Steel pipe 16 Rotation support 18 Rotation drive motor (Rotation drive means) 19 Stretching mechanism (Fixing means) 23 Laser welding nozzle (Laser welding means) 26 Linear movement means 35 Sensing device A, B Rotation center of laser welding nozzle O Rotation center line of rotation support P Weld groove position

Continuation of the front page (51) Int.Cl. ⁷ identification symbol FI B23K 101: 06 B23K 101: 06 101: 10 101: 10 103: 04 103: 04 (58) Investigated field (Int.Cl. ⁷ , DB name ) B23K 26/00-26/30 B23K 15/00 B23K 37/02

Claims (8)

(57) [Claims] 1. A laser welding method for welding a peripheral joint of a steel pipe by using a laser beam capable of guiding light with an optical fiber, wherein a welding cart equipped with a laser welding means inserted into the steel pipe is run to match the skin. Stops at the approximate butt position of the later steel pipe, and the laser welding means can rotate around the pipe axis of the steel pipe.
A sensing device mounted on the rotating support by rotating the rotating support and fixing the center of rotation of the rotating support, which is integrally erected so that it can be moved in the axial direction , approximately in line with the center axis of the steel pipe. Detects the welding groove position of the steel pipe, calculates the welding groove position for each welding position based on the detection result, and rotates the laser welding means until the rotation center reaches the calculated welding start position. One-dimensional control so that the laser welding means moves along the rotation center line of the rotating support according to the rotation of the rotating support using the calculated data of the welding groove position after adjusting the movement along the rotation center line of A laser welding method comprising rotating a rotary support, irradiating a laser beam to a welding groove position by laser welding means, and performing welding. 2. The laser welding method according to claim 1, wherein after the laser welding means is moved and adjusted along the rotation center line of the rotary support, the focal point of the laser beam is correctly adjusted with respect to the welding portion. In addition to controlling the position in the radial direction of the steel pipe so as to hit it, one-dimensionally so that the laser welding means moves along the rotation center line of the rotating support according to the rotation of the rotating support using the calculation data of the welding groove position A laser welding method, wherein the welding is performed by rotating the rotating support and irradiating a laser beam to a welding groove position by laser welding means while controlling. 3. A laser welding apparatus for welding a peripheral joint of a steel pipe using a laser beam capable of guiding light with an optical fiber, wherein the welding apparatus is installed so as to be able to run in the steel pipe during welding, and after the skin of the steel pipe is fitted. A welding bogie that stops at the approximate abutment position, a rotating support body integrally erected so that the laser welding means is rotatable and movable in the pipe axis direction, and a rotation center line of the rotating support body is set at the center of the steel pipe. A fixing means for fixing the rotating support in the radial direction of the steel pipe so as to be substantially coincident with the axis, and sensing mounted on the rotating support and detecting a welding groove position of the steel pipe when rotating the rotating support during welding. A linear moving means for moving the laser welding means along the rotation center line of the rotating support in the steel pipe; and calculating a welding groove position based on a detection result by the sensing device, and performing a linear movement. After controlling the operation of the moving means and moving the laser welding means to the position where the rotation center of the laser welding means reaches the calculated welding groove position, it is adjusted to the rotation of the rotary support using the calculated data of the welding groove position Control means for controlling the rotation drive means to rotate the rotary support while controlling the laser welding means in one-dimensional manner so as to move along the rotation center line of the rotary support. Construction equipment. 4. A laser welding apparatus according to claim 3, wherein said laser welding means is capable of controlling a position of said laser welding means in a radial direction of a steel pipe so that a laser beam is correctly focused on a welding portion. Laser welding equipment characterized by being installed upright in a building. 5. A laser welding method for welding a circumferential joint of a steel pipe using a laser beam capable of guiding light with an optical fiber, wherein a bogie equipped with a laser welding means inserted into the steel pipe is run and the skin is fitted. Stop at approximately the butt position of the steel pipe, and rotate the laser welding means around the pipe axis of the steel pipe.
The rotation center line of the rotating support, which is integrally erected so that it can be moved in the axial direction, is fixed substantially in line with the center axis of the steel pipe, and the sensing device mounted on the rotating support determines the welding start position of the steel pipe. After detecting and adjusting the laser welding means along the rotation center line of the rotary support until the rotation center reaches the welding start position, when rotating the rotary support, the welding groove position is detected. While using the data, one-dimensional control is performed so that the laser welding means moves along the rotation center line of the rotating support according to the rotation of the rotating support, and the laser beam is moved to the welding groove position by the laser welding means. Laser welding method characterized by irradiation and welding. 6. The laser welding method according to claim 5, wherein after the laser welding means is moved and adjusted along the rotation center line of the rotary support, the focal point of the laser beam is correctly adjusted with respect to the welding portion. In addition to controlling the position in the radial direction of the steel pipe so that it hits, while rotating the rotating support, while detecting the welding groove position, the laser welding means uses the data to match the rotation of the rotating support and rotates the rotating support. A laser welding method characterized by irradiating a laser beam to a welding groove position by laser welding means while performing one-dimensional control so as to move along a rotation center line of a body, and performing welding. 7. A laser welding apparatus for welding a peripheral joint of a steel pipe using a laser beam capable of guiding light with an optical fiber, wherein the welding apparatus is installed so as to be able to run in the steel pipe during welding, and after the skin of the steel pipe is fitted. A welding bogie that stops at the approximate abutment position, a rotary support that is integrally erected so that the laser welding means is rotatable and movable in the pipe axis direction, and a rotation center line of the rotary support is aligned with a center axis of the steel pipe. A fixing means for fixing the rotary support in the radial direction of the steel pipe so as to substantially match with the above, and a sensing for mounting the rotary support on the rotary support and detecting a welding groove position of the steel pipe when rotating the rotary support during welding work. A linear moving means for moving the laser welding means along the rotation center line of the rotating support in the steel pipe; and controlling an operation of the linear moving means based on a detection result by the sensing device. After the laser welding means has moved to the welding start position, the rotation support means is controlled to rotate the rotating support, and at the time of rotation of the rotating support, the welding groove position is detected while using the data. Control means for one-dimensionally controlling the movement of the rotary support in the direction of the rotation center line, and a laser welding apparatus. 8. The rotary support according to claim 7, wherein the laser welding means is capable of controlling the position of the laser welding means in the radial direction of the steel pipe so that the focus of the laser beam is correctly applied to the welding portion. Laser welding equipment characterized by being installed upright in a building.