Welding apparatus and welding method

Abstract

By performing welding path and sensing separately, the present invention provides a welding apparatus and welding method that can appropriately measure the shape of the welding area and appropriately weld the area. [Solution] The welding apparatus 100 includes a sensor 12 for measuring welding locations on the surface of a steel pipe 50, a sensor movement direction setting unit 120 for setting whether to measure welding locations while moving the sensor 12 in either the welding direction or the return direction, a measurement unit 130 for measuring welding locations while moving the sensor 12 in the sensor movement direction set by the sensor movement direction setting unit 120, and a welding unit 140 for welding the welding locations measured by the measurement unit 130 while moving along the outer circumference of the steel pipe 50 in the welding direction.

Description

Technical Field

[0001] The present invention relates to a welding apparatus and a welding method.

Background Art

[0002] In recent years, steel pipe columns formed by connecting steel pipes by welding are used in large buildings such as high-rise buildings. When connecting steel pipes, a rail is arranged so as to go around the outer periphery of the steel pipes, and the connecting portions of the steel pipes are welded while a welding robot travels along the rail.

[0003] For example, Patent Document 1 discloses that in a welding process in which welding is performed while a welding robot travels along a rail, groove information is acquired by a sensor while performing a welding pass by an end effector, and the position of the end effector is adjusted based on the information so as to follow the planned welding pass.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] However, in the welding process disclosed in Patent Document 1, since sensing is performed while performing the welding pass, there is a risk that the shape of the welded portion cannot be properly measured due to the influence of spatter, fume, arc light and the like.

[0006] Accordingly, an object of the present invention is to provide a welding apparatus and a welding method capable of properly measuring the shape of a welded portion and properly welding the welded portion by performing the welding pass and the sensing separately.

Means for Solving the Problems

[0007] A welding apparatus according to one aspect of the present invention is a welding apparatus that welds a steel pipe while moving along its outer circumference, comprising: a sensor for measuring a welding location on the surface of the steel pipe; a sensor movement direction setting unit for setting whether to measure the welding location while moving the sensor in either the welding direction or the return direction opposite to the welding direction; a measurement unit for measuring the welding location while moving the sensor in the sensor movement direction set by the sensor movement direction setting unit; and a welding unit for welding the welding location measured by the measurement unit while moving along the outer circumference of the steel pipe in the welding direction.

[0008] In this embodiment, the sensor movement direction setting unit sets whether to measure the welding location while moving the sensor in either the welding direction or the return direction. The measurement unit measures the welding location while moving the sensor in the sensor movement direction set by the sensor movement direction setting unit, and the welding unit welds the welding location measured by the measurement unit while moving along the outer circumference of the steel pipe in the welding direction. As a result, by performing welding path and sensing separately, the shape of the welding location can be appropriately measured and the welding location can be appropriately welded.

[0009] In the above embodiment, the sensor movement direction setting unit may set the sensor movement direction by selection by the user.

[0010] According to this embodiment, since the sensor movement direction is set by the user, the sensor movement direction desired by the user can be set according to the situation. As a result, appropriate welding can be achieved according to the situation.

[0011] In the above embodiment, the user may be able to pre-set the direction of sensor movement.

[0012] According to this embodiment, the user pre-sets the direction of sensor movement, enabling the welding robot to perform welding appropriately.

[0013] In the above embodiment, when performing multi-layer welding of a welding location on the surface of a steel pipe, the user may be able to set the direction of sensor movement in any of the multiple welding passes.

[0014] According to this embodiment, when performing multi-layer welding, the user can set the sensor movement direction in any of the multiple welding passes. Therefore, even in the middle of multi-layer welding, the sensor movement direction can be set (changed) in any of the multiple welding passes. As a result, welding can be achieved more appropriately in terms of high-precision measurement and reduction of welding time.

[0015] In the above embodiment, when multi-layer welding is performed on the surface of the steel pipe, the sensor movement direction setting unit may set the sensor movement direction according to each of the multiple welding passes.

[0016] According to this embodiment, when performing multi-layer welding, the sensor movement direction setting unit sets the sensor movement direction according to each of the multiple welding passes, thereby enabling more appropriate welding depending on the situation, such as high-precision measurement and reduction of welding time.

[0017] A welding method according to one aspect of the present invention is a welding method performed by a welding apparatus that moves along the outer circumference of a steel pipe while welding, and includes: a sensor movement direction setting step of setting whether to measure the welding location while moving a sensor that measures the welding location on the surface of the steel pipe in either the welding direction or the return direction opposite to the welding direction; a measurement step of measuring the welding location while moving the sensor in the sensor movement direction set in the sensor movement direction in the sensor movement setting step; and a welding step of welding the welding location measured in the measurement step while moving along the outer circumference of the steel pipe in the welding direction.

[0018] According to this aspect, in the sensor movement direction setting step, it is set whether to measure the welding location while moving the sensor in either the welding direction or the return direction as the sensor movement direction. In the measurement step, the welding location is measured while moving the sensor in the sensor movement direction set in the sensor movement direction setting step, and in the welding step, the welding location measured in the measurement step is welded while moving in the welding direction along the outer periphery of the steel pipe. As a result, by performing the welding pass and the sensing separately, the shape of the welding location can be appropriately measured and the welding location can be properly welded. Effects of the Invention

[0019] According to the present invention, by performing the welding pass and the sensing separately, it is possible to provide a welding apparatus and a welding method capable of appropriately measuring the shape of a welding location and properly welding the welding location. Brief Description of the Drawings

[0020] [Figure 1] 1 is a schematic diagram showing the system configuration of a welding robot system 1 according to an embodiment of the present invention. [Figure 2] It is a diagram showing a state where two welding robots 10A and 10B can each travel along half the circumference of a steel pipe 50. [Figure 3] It is a functional block diagram showing each function of a welding apparatus 100 according to an embodiment of the present invention. [Figure 4] It is a flowchart showing the procedure of a welding method M100 executed by the welding apparatus 100 according to an embodiment of the present invention. [Figure 5] It is a flowchart showing a specific example of the procedure of a welding method M200 executed by the welding apparatus 100 according to an embodiment of the present invention when the welding direction is set as the sensor movement direction. [Figure 6] It is a flowchart showing a specific example of the procedure of a welding method M300 executed by the welding apparatus 100 according to an embodiment of the present invention when the return direction is set as the sensor movement direction. Modes for Carrying Out the Invention

[0021] Hereinafter, embodiments of the present invention will be specifically described with reference to the drawings. The embodiments described below are merely specific examples for implementing the present invention, and are not intended to limit the interpretation of the present invention. In addition, to facilitate understanding of the description, identical reference numerals are assigned to identical constituent elements in each drawing as far as possible, and redundant descriptions may be omitted.

[0022] <One Embodiment> [Overview of Welding Robot System] Figure 1 is a schematic diagram showing the system configuration of a welding robot system 1 according to an embodiment of the present invention. As shown in Figure 1, the welding robot system 1 includes a welding robot 10, a sensor monitoring device 20, a robot control device 30, a welding wire feeding device 40, and a welding power source (not shown). A welding torch 11 as an end effector and a laser profiler 12 as a sensor are attached to the welding robot 10.

[0023] The welding robot system 1 connects steel pipes 50A and 50B by welding the outer peripheries (connection portion 51) of the steel pipes 50A and 50B, so as to form, for example, steel pipe columns (steel frame columns) used in large buildings such as high-rise buildings.

[0024] The steel pipes 50A and 50B form steel pipe columns such as column pillars and four-sided box pillars, for example, and in a state of being temporarily fixed by erection pieces 70, the steel pipes 50A and 50B are connected by performing so-called groove welding on the connection portion 51 of the steel pipes 50A and 50B. Hereinafter, the steel pipes 50A and 50B may be collectively referred to as the steel pipe 50.

[0025] The welding robot 10 is connected to a robot control device 30 via a cable and performs arc welding based on operation commands from the robot control device 30. For example, the welding robot 10 may perform welding while traveling along a rail 60 that is arranged to circle the steel pipe 50A along its outer circumference. A welding wire is fed from a welding torch 11 provided at the tip of the welding robot 10, and arc welding is performed by moving the tip of the welding torch 11 along the connecting portion 51 of the steel pipes 50A and 50B and generating an arc between the steel pipes 50A and 50B.

[0026] The welding torch 11 is connected to a welding power source via a cable and receives welding voltage and welding current to the welding wire. In arc welding, when the welding wire is momentarily brought into contact with the metal material (in this case, the connecting portion 51 in the steel pipes 50A and 50B) and current is applied, an arc discharge is generated between the welding wire and the connecting portion 51, and welding is performed by melting the welding wire and the connecting portion 51 with the heat of the generated arc.

[0027] The laser profiler 12 irradiates the object to be sensed with laser light and measures its shape based on the reflected light. For example, the laser profiler 12 may be equipped with a laser light source, irradiation and receiving lenses, and a camera (CMOS), and measures the shape of the weld by irradiating the welded area with laser light, imaging the reflected light with the CMOS, and measuring the shape of the welded area.

[0028] The sensor monitoring device 20 controls and monitors the laser profiler 12 attached to the welding robot 10. For example, the sensor monitoring device 20 may control the light emitted from the laser light source of the laser profiler 12, monitor the light received by the laser profiler 12, or acquire profile data obtained by the laser profiler 12.

[0029] The robot control device 30 is a device that controls the welding robot 10. The robot control device 30 controls the welding robot 10, the sensor monitoring device 20, the welding wire feeding device 40, and the welding power supply, for example, based on a work program. Here, the work program includes teaching data that has been pre-programmed and generated so that the welding robot 10 welds the connecting portion 51 while traveling along the rail 60.

[0030] For example, the work program (teaching data) may include operational information of the welding robot 10, such as its position, posture, and movement speed; information regarding the feeding of the welding wire 11; and information regarding welding conditions, such as welding voltage, welding current, welding speed, and welding time. Furthermore, this information included in the work program (teaching data) may be set by an operator using an operating device such as a teach pendant, or by actually operating the welding robot 10.

[0031] The welding wire feeding device 40 is controlled by the robot control device 30 and, for example, feeds a predetermined length of welding wire in the forward direction (the direction from the tip of the welding torch toward the connecting portion 51 of the steel pipes 50A and 50B) at a predetermined feeding speed, or feeds it in the reverse direction.

[0032] The welding power supply is connected via a cable to the welding robot 10 (welding torch 11) and the welding wire feeding device 40, and supplies welding voltage and welding current to the welding torch 11 in the welding robot 10 based on commands from the robot control device 30.

[0033] In this manner, the welding robot system 1 measures the shape of the welding area by sensing the connecting portion 51 using a laser profiler 12 while the welding robot 10 travels along the rail 60 around the steel pipe 50. Then (separately), the welding robot 10 travels along the rail 60 around the steel pipe 50 and welds the welding area using a welding torch 11 according to the measured shape of the welding area.

[0034] Although the welding robot system 1 was equipped with one welding robot 10, it may be equipped with multiple welding robots. For example, it may be equipped with two welding robots, and each of the two welding robots may travel around half the circumference of the steel pipe 50 while welding the connecting portion 51 of the steel pipes 50A and 50B.

[0035] Figure 2 shows how two welding robots 10A and 10B can each travel half the circumference of a steel pipe 50. As shown in Figure 2, welding robot 10A can move along the rail 60 in the range RA from position A1 to position A2, and welding robot 10B can move along the rail 60 in the range RB from position B1 to position B2. Note that in Figure 2, the sensor monitoring device, robot control device, welding wire feeding device, etc. connected to the two welding robots 10A and 10B are omitted.

[0036] The welding robot 10A, for example, travels along the rail 60 on the outer circumference of the steel pipe 50 from position A1 to position A2 (or from position A2 to position A1), and uses a laser profiler 12 to sense the connecting portion 51 of the steel pipe 50 corresponding to the range RA from position A1 to position A2, thereby measuring the shape of the welding location. Then, the welding robot 10A, for example, travels along the rail 60 on the outer circumference of the steel pipe 50 from position A1 to position A2 (or from position A2 to position A1), and uses a welding torch 11 to weld the connecting portion 51 of the steel pipe 50 corresponding to the range RA from position A1 to position A2, according to the measured shape of the welding location.

[0037] Similarly, the welding robot 10B travels along the rail 60 on the outer circumference of the steel pipe 50 from position B1 to position B2 (or from position B2 to position B1), for example, and uses the laser profiler 12 to sense the connecting portion 51 of the steel pipe 50 corresponding to the range RB from position B1 to position B2, thereby measuring the shape of the welding location. Then, while traveling along the rail 60 on the outer circumference of the steel pipe 50 from position B1 to position B2 (or from position B2 to position B1), the welding robot 10B uses the welding torch 11 to weld the connecting portion 51 of the steel pipe 50 corresponding to the range RB from position B1 to position B2, according to the measured shape of the welding location.

[0038] In this manner, in the welding robot system 1, two welding robots 10A and 10B each travel halfway around the steel pipe 50, measuring the shape of the welding points of the connecting portions 51 around the entire circumference of the steel pipe 50, and welding the connecting portions 51 around the entire circumference of the steel pipe 50. Hereinafter, welding robots 10A and 10B may be collectively referred to as welding robot 10.

[0039] [Configuration of welding equipment] Figure 3 is a functional block diagram showing the functions of a welding apparatus 100 according to one embodiment of the present invention. As shown in Figure 3, the welding apparatus 100 has a functional configuration comprising a robot control unit 110, a sensor movement direction setting unit 120, a measurement unit 130, and a welding unit 140. The welding robot 10 travels along the rail 60 around the outer circumference of the steel pipe 50, and measures the shape of the welding area using a laser profiler 12, and then welds the measured welding area using a welding torch 11.

[0040] Of these functions, for example, the robot control unit 110 is a function realized by the robot control device 30. The sensor movement direction setting unit 120 is a function realized by the operator (user) using an operating device, the measurement unit 130 is a function realized by the sensor monitoring device 20 and the laser profiler 12, and the welding unit 140 is a function realized by the welding wire feeding device 40, the welding power supply and the welding robot 10 (welding torch 11).

[0041] The sensor movement direction setting unit 120 may have all or part of its functions provided in the robot control device 30, or it may be a function realized through cooperation between the operating device and the robot control device 30. The measurement unit 130 may have the function of controlling and monitoring the laser profiler 12 to acquire profile data provided in either the sensor monitoring device 20 or the robot control device 30, or it may be provided in a distributed (coordinated) manner across both the sensor monitoring device 20 and the robot control device 30.

[0042] The robot control unit 110 controls the operation of the welding robot 10. For example, based on a preset or user-defined sensor movement direction, the robot control unit 110 controls the welding robot 10 to travel along the rail 60 around the outer circumference of the steel pipe 50 in order to measure the shape of the welding area using the laser profiler 12. Based on the measured shape of the welding area (profile data) and the work program (teaching data), the robot control unit 110 controls the welding robot 10 to weld the welding area using the welding torch 11 while it travels along the rail 60 around the outer circumference of the steel pipe 50.

[0043] The sensor movement direction setting unit 120 sets whether to measure the welding location while moving the laser profiler 12 (sensor) in either the welding direction or the return direction opposite to the welding direction. When measuring the shape of the welding location using the laser profiler 12, the welding robot 10 is moved along the rail 60 to measure the outer circumference of the steel pipe 50. In this case, the setting determines whether to move the welding robot 10 in the same direction as the welding direction when actually welding the connecting portion 51 while moving along the rail 60, or in the opposite direction (return direction) (sensor movement direction) while measuring.

[0044] More specifically, in the case of the welding robot 10A shown in Figure 2, for example, it is assumed that the robot will weld a connecting portion 51 corresponding to the range RA from position A1 to position A2 while traveling along the rail 60 on the outer circumference of the steel pipe 50 from position A1 to position A2 (counterclockwise). In this case, the sensor movement direction setting unit 120 sets either the welding direction (direction from position A1 to position A2: counterclockwise) or the return direction (direction from position A2 to position A1: clockwise) as the sensor movement direction when measuring the shape of the welding area using the laser profiler 12.

[0045] When the sensor movement direction is set to the welding direction, the welding robot 10 measures the shape of the welding area while moving in the actual welding direction, thus enabling more accurate measurement of the shape of the welding area.

[0046] If the sensor movement direction is set to the return direction, for example, in the case of multi-layer welding, the welding robot 10 can measure the shape of the welded area when it returns to the welding start position after actually moving in the welding direction and performing the welding.

[0047] The sensor movement direction setting unit 120 may set the sensor movement direction by selection by the user. For example, the operator (user) uses an operating device to select either the welding direction or the return direction as the sensor movement direction. The sensor movement direction setting unit 120 then sets the sensor movement direction selected by the operator.

[0048] Furthermore, the operator may pre-set the direction of sensor movement, or, for example, when multi-layer welding is performed on the connecting portion 51 (welding point) of the steel pipe 50, the operator may set (change) the direction of sensor movement during the process (at any of the welding passes).

[0049] The sensor movement direction setting unit 120 may set the sensor movement direction according to each of the multiple welding passes when multi-layer welding is performed on the connecting portion 51 (welding location) of the steel pipe 50.

[0050] For example, the sensor movement direction setting unit 120 may set the sensor movement direction to the welding direction for the first half of the multiple welding passes, and the measurement unit 130 may measure the shape of the welded area while moving the welding robot 10 in the welding direction. The sensor movement direction setting unit 120 may set the sensor movement direction to the return direction for the second half of the multiple welding passes, and the measurement unit 130 may measure the shape of the welded area as the welding robot 10 moves in the return direction. Here, the first half refers to the welding passes from the beginning to the middle of the multiple welding passes used for multi-layer welding, and the second half refers to the welding passes from the middle onward.

[0051] In this way, when performing multi-layer welding, by setting the sensor movement direction to the welding direction in the first half, the shape of the welding area can be measured with higher precision, and by setting the return direction in the second half, the time can be shortened, thereby enabling proper multi-layer welding.

[0052] Furthermore, the method is not limited to switching the sensor movement direction only in the middle welding pass among multiple welding passes in multi-layer welding. For example, when measuring the welding location corresponding to the first to a predetermined welding pass among multiple welding passes in multi-layer welding, the sensor movement direction may be set to the welding direction, and thereafter set to the return direction.

[0053] Furthermore, in multi-layer welding, the sensor movement direction may be appropriately set (switched) between the welding direction and the return direction, depending on the shape of the welded area, including bead sagging, and the total time spent on welding.

[0054] Furthermore, the sensor movement direction may be set to the welding direction at predetermined intervals among the multiple welding passes used in multi-layer welding. In other words, the shape of the welded area can be measured with higher precision at predetermined intervals.

[0055] The measurement unit 130 measures the welding area while moving the laser profiler 12 (sensor) in the sensor movement direction set by the sensor movement direction setting unit 120. For example, the measurement unit 130 measures the welding area using the laser profiler 12 while moving the welding robot 10 along the rail 60 around the outer circumference of the steel pipe 50 in the sensor movement direction (welding direction or return direction) set by the sensor movement direction setting unit 120, and acquires the shape of the welding area.

[0056] The welding unit 140 moves along the outer circumference of the steel pipe 50 in the welding direction and welds the welding points measured by the measurement unit 130. For example, based on the measured welding points (profile data) and work program (teaching data), the robot control unit 110 moves the welding robot 10 along the rail 60 to the outer circumference of the steel pipe 50 and welds the welding points using the welding torch 11. Here, since the shape of the welding points is appropriately measured by the measurement unit 130, the welding torch 11 can be appropriately positioned at the welding location according to the shape of the welding points, thus enabling more accurate welding.

[0057] [Welding Method] Figure 4 is a flowchart showing the steps of welding method M100 performed by welding apparatus 100 according to one embodiment of the present invention. As shown in Figure 4, welding method M100 includes steps S110 to S130.

[0058] In step S110, the sensor movement direction setting unit 120 sets the sensor movement direction (sensor movement direction setting step). Specifically, when measuring the welded area on the surface of the steel pipe 50 using the laser profiler 12, the sensor movement direction setting unit 120 sets whether to move the welding robot 10 in the welding direction or in the opposite direction (sensor movement direction) while measuring the welded area.

[0059] In step S120, the measurement unit 130 measures the welding location while moving in the sensor movement direction set in step S110 (measurement step). Specifically, while the robot control unit 110 moves the welding robot 10 in the sensor movement direction set in step S110, the measurement unit 130 measures the welding location using the laser profiler 12 attached to the welding robot 10.

[0060] In step S130, the welding unit 140 moves in the welding direction and welds the welding location measured in step S120 (welding step). Specifically, the robot control unit 110 moves the welding robot 10 along the outer circumference of the steel pipe 50 in the welding direction, and the welding unit 140 positions the welding torch 11 at the welding location based on the shape of the welding location measured in step S120 and performs welding.

[0061] [Specific example of welding method 1] Figure 5 is a flowchart showing a specific example of the procedure of welding method M200 performed by a welding apparatus 100 according to one embodiment of the present invention, when the welding direction is set in the direction of sensor movement. As shown in Figure 5, welding method M200 includes steps S210 to S250, the welding direction is set in the direction of sensor movement, and it is a welding method using multiple welding passes in multilayer welding.

[0062] In step S210, the robot control unit 110 moves the welding robot 10 to the welding start position. Specifically, the welding robot 10A shown in Figure 2 is moved to position A1. Here, position A1 is defined as the welding start position for the welding robot 10A, and position A2 is defined as the welding end position.

[0063] In step S220, the measurement unit 130 measures the welding location while moving in the welding direction from the welding start position to the welding end position. Specifically, the robot control unit 110 moves the welding robot 10A shown in Figure 2 along the rail 60 to the outer circumference of the steel pipe 50 from position A1 to position A2 (counterclockwise), and the measurement unit 130 uses the laser profiler 12 attached to the welding robot 10A to measure the welding location of the connecting portion 51 corresponding to the range RA from position A1 to position A2.

[0064] In step S230, the robot control unit 110 returns the welding robot 10 from the welding end position to the welding start position. Specifically, after the welding location of the connecting portion 51 corresponding to the range RA from position A1 to position A2 is measured in step S220, the robot control unit 110 moves the welding robot 10A from position A2 towards position A1 (clockwise).

[0065] In step S240, the welding unit 140 welds the welding area while moving in the welding direction from the welding start position. Specifically, the robot control unit 110 moves the welding robot 10A, which was returned to position A1 in step S230, along the rail 60 to the outer circumference of the steel pipe 50 from position A1 to position A2 (counterclockwise), while the welding unit 140 positions the welding torch 11 at the welding position and welds based on the shape of the welding area measured in step S220.

[0066] In step S250, the welding apparatus 100 determines whether welding is complete. If welding is complete ("Yes" in step S250), the process ends. If welding is not complete ("No" in step S250), the process returns to step S210 and repeats steps S210 to S250 until welding is complete. Specifically, the welding apparatus 100 welds the connecting portion 51 by moving the welding robot 10 along the rail 60 to the outer circumference of the steel pipe 50 based on the work program. If multi-layer welding with multiple welding passes is completed ("Yes" in step S250), the process ends. If welding is not complete ("No" in step S250), the process returns to step S210 to execute the next welding pass and repeats steps S210 to S250 until welding is complete.

[0067] As described above, according to welding method M200, the welding robot 10 measures the shape of the welding area while moving in the actual welding direction. Therefore, it can measure the shape of the welding area with higher precision without being affected by backlash or other factors that occur in the movement mechanism of the welding robot 10 as it travels along the rail 60. As a result, the welding robot 10 can weld more appropriately.

[0068] [Specific example of welding method 2] Figure 6 is a flowchart showing a specific example of the procedure of welding method M300 performed by a welding apparatus 100 according to one embodiment of the present invention, when the return direction is set in the direction of sensor movement. As shown in Figure 6, welding method M300 includes steps S310 to S330, the return direction is set in the direction of sensor movement, and it is a welding method using multiple welding passes in multilayer welding.

[0069] In step S310, the measurement unit 130 measures the welding location while moving in the reverse direction from the welding end position to the welding start position. Specifically, the robot control unit 110 moves the welding robot 10A shown in Figure 2 along the rail 60 to the outer circumference of the steel pipe 50 from position A2 to position A1 (clockwise), and the measurement unit 130 uses the laser profiler 12 attached to the welding robot 10A to measure the welding location of the connecting portion 51 corresponding to the range RA from position A2 to position A1. Initially, the robot control unit 110 may move the welding robot 10A to position A2, and thereafter, after the welding is completed in step S320 described later, the welding robot 10A is located at position A2, which is the welding end position.

[0070] In step S320, the welding unit 140 welds the welding area while moving in the welding direction from the welding start position. Specifically, the robot control unit 110 moves the welding robot 10A, which was returned to position A1 in step S310, along the rail 60 towards position A2 (counterclockwise) along the outer circumference of the steel pipe 50, while the welding unit 140 positions the welding torch 11 at the welding position based on the shape of the welding area measured in step S310 and performs welding.

[0071] In step S330, the welding apparatus 100 determines whether welding is complete. If welding is complete ("Yes" in step S330), the process ends. If welding is not complete ("No" in step S330), the process returns to step S310 and repeats steps S310 to S330 until welding is complete. Specifically, the welding apparatus 100 welds the connecting portion 51 by moving the welding robot 10 along the rail 60 to the outer circumference of the steel pipe 50 based on the work program. If multi-layer welding with multiple welding passes is completed ("Yes" in step S330), the process ends. If it is not complete ("No" in step S330), the process returns to step S310 to execute the next welding pass and repeats steps S310 to S330 until welding is complete.

[0072] Furthermore, if the process returns to step S310 to execute the next welding pass, after the welding is completed in step S320, the welding robot 10A is at position A2, which is the welding completion position, and therefore can immediately start the measurement in step S310.

[0073] As described above, according to welding method M300, the welding robot 10 moves in the welding direction while welding, and then, when returning to the welding start position, it moves in the opposite direction to the welding direction while measuring the shape of the welded area. As a result, the welding robot 10 can achieve multi-layer welding in a shorter time.

[0074] As described above, according to the welding apparatus 100 and welding methods M100, M200, and M300 of one embodiment of the present invention, a laser profiler 12 for measuring welding locations on the surface of a steel pipe 50 is attached to a welding robot 10, and a sensor movement direction setting unit 120 sets the welding direction or return direction as the movement direction (sensor movement direction) of the welding robot 10 when measuring welding locations. While the welding robot 10 (laser profiler 12) travels along the rail 60 on the outer circumference of the steel pipe 50 in the sensor movement direction set by the sensor movement direction setting unit 120, the measurement unit 130 measures the welding locations. Then, while the welding robot 10 moves along the outer circumference of the steel pipe 50 in the welding direction, the welding unit 140 welds the welding locations using a welding torch 11 according to the shape of the welding locations measured by the measurement unit 130. As a result, by performing welding paths and sensing separately, the shape of the welding locations can be appropriately measured and the welding locations can be appropriately welded.

[0075] In this embodiment, the welding robot 10 welded the connecting portion 51 of the steel pipes 50A and 50B. However, in the case of multi-layer welding, some of the welding may be done manually by an operator. For example, the initial welding (the first few sections) may be done manually by an operator, and once the steel pipes 50A and 50B are connected to a certain extent, the erection piece 70 may be removed, and the welding robot 10 may continue the welding thereafter. This eliminates the need for the welding robot 10 to consider avoiding the erection piece 70 when positioning the tip of the welding torch 11 at the welding position, allowing for easy automatic welding.

[0076] Furthermore, in this embodiment, the explanation mainly used two welding robots 10A and 10B that travel halfway around the steel pipe 50 as shown in Figure 2 as an example. However, even with a single welding robot 10 that travels a full circle around the steel pipe 50 as shown in Figure 1, the present invention can be applied if it moves in the return direction opposite to the welding direction and returns to the welding start position. For example, there may be cases where it is difficult for the welding robot 10 to travel a full circle around the steel pipe 50A due to circumstances such as joints in the rails 60 arranged to circle the steel pipe 50A or the routing of cables. When the welding robot 100 moves in the return direction opposite to the welding direction and returns to the welding start position, it can measure the shape of the welded area while moving in the return direction opposite to the welding direction, or it can measure the shape of the welded area while moving in the welding direction after returning to the welding start position.

[0077] The embodiments described above are provided to facilitate understanding of the present invention and are not intended to limit its interpretation. The elements, arrangement, materials, conditions, shapes, and sizes of the embodiments are not limited to those exemplified and can be modified as appropriate. Furthermore, it is possible to partially substitute or combine the configurations shown in different embodiments. [Explanation of Symbols]

[0078] 1…Welding robot system, 10, 10A, 10B…Welding robot, 11…Welding torch, 12…Laser profiler (sensor), 20…Sensor monitoring device, 30…Robot control device, 40…Welding wire feeding device, 50, 50A, 50B…Steel pipe, 51…Connecting part, 60…Rail, 70…Erection piece, 100…Welding device, 110…Robot control unit, 120…Sensor movement direction setting unit, 130…Measurement unit, 140…Welding unit, A1, A2, B1, B2…Position, RA, RB…Range, M100, M200, M300…Welding method, S110~S130…Each step of welding method M100, S210~S250…Each step of welding method M200, S310~S330…Each step of welding method M300

Claims

1. A welding device that moves along the outer circumference of a steel pipe while welding, A sensor for measuring the welding locations on the surface of the steel pipe, A sensor movement direction setting unit sets whether to measure the welding location while moving the sensor in either the welding direction or the return direction opposite to the welding direction. A measuring unit that measures the welding location while moving the sensor in the sensor movement direction set by the sensor movement direction setting unit, The welding unit comprises a welding unit that moves along the outer circumference of the steel pipe in the welding direction and welds the welding location measured by the measuring unit, Welding equipment.

2. The sensor movement direction setting unit sets the sensor movement direction by being selected by the user. The welding apparatus according to claim 1.

3. The user can pre-set the direction of movement of the sensor. The welding apparatus according to claim 2.

4. When the user performs multi-layer welding on the surface of the steel pipe, the user can set the direction of movement of the sensor in any of the welding passes among the multiple welding passes. The welding apparatus according to claim 2.

5. The sensor movement direction setting unit sets the sensor movement direction according to each of the multiple welding passes when multi-layer welding is performed on the surface of the steel pipe. The welding apparatus according to claim 1.

6. A welding method performed by a welding device that moves along the outer circumference of a steel pipe while welding, A sensor movement direction setting step, which sets whether to measure the welded area on the surface of the steel pipe while moving the sensor in either the welding direction or the return direction opposite to the welding direction, A measurement step in which the sensor is moved in the sensor movement direction set in the sensor movement direction setting step while measuring the welding location, A welding step includes welding the welding location measured in the measurement step while moving along the outer circumference of the steel pipe in the welding direction, Welding method.

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