Weaving control method, welding control device, welding system, welding method, and weaving control program

Abstract

To provide a weaving control method for obtaining good welding quality in various attitude welding such as download welding, lateral welding and vertical rising welding using a portable welding robot moving on a guide rail.SOLUTION: A welding control method includes a setting step of setting at least a condition of a weaving reference trajectory relating to a reference distance for determining a weaving pattern, and a speed condition calculation step of calculating a speed condition for giving a command to a robot moving mechanism for moving a portable welding robot on the basis of the weaving pattern determined on the basis of the setting step for each of a plurality of prescribed direction components, wherein a command of a stop signal, and a command of a start signal performed immediately after the command of the stop signal or after elapse of the prescribed stop time for each of the speed conditions of the plurality of direction components calculated in the speed condition calculation step are synchronized when at least a weaving end reaches.SELECTED DRAWING: Figure 10

Description

[Technical field]

[0001] The present invention relates to a weaving control method, a welding control device, a welding system, a welding method, and a weaving control program for welding a workpiece having a groove using a portable welding robot. [Background technology]

[0002] In the manufacturing of welded structures such as shipbuilding, steel frames, and bridges, welding work in factories places emphasis on work efficiency, and systems that apply large, stationary multi-axis welding robots are often used, mainly for flat position welding. A system that applies a stationary multi-axis welding robot is, for example, a welding robot system in which the workpiece (hereinafter sometimes referred to as "work") is placed in a stationary positioner and automatically welded using a multi-axis welding robot. On the other hand, manual welding such as semi-automatic welding or automatic welding using a lightweight, small, portable welding robot that can be carried by a single worker is often used for on-site welding where a large multi-axis welding robot cannot be used, or for welding small components or components with complex shapes. In particular, portable welding robots are being increasingly used for on-site welding, taking advantage of their portability.

[0003] In the arc welding method, in order to obtain sufficient penetration and an appropriate welded weld shape in the weld joint of the workpiece, the welding torch is swung in the groove width direction or groove depth direction of the weld joint while welding in the weld line direction. This swinging of the welding torch is called "weaving", "oscillating" or "rod driving", and the weaving pattern differs according to the welding position. Hereinafter, the swinging of the welding torch is referred to as "weaving", and the trajectory formed by this weaving is referred to as "weaving pattern". By having the above-mentioned multi-axis welding robot or portable welding robot perform such weaving of the welding torch, sufficient penetration and an appropriate welded weld shape can be obtained, and the welding can be automated.

[0004] Here, Patent Document 1 shows a stationary welding device that combines an articulated welding robot and a rotary positioner, and also shows that in horizontal welding, appropriate weld buildup can be obtained by making the weaving serrated, as shown in Fig. 17 of Patent Document 1. Furthermore, it also shows that in vertical welding, appropriate weld buildup can be obtained by making the weaving rectangular.

[0005] Patent Document 2 shows an automatic welding device that incorporates three orthogonal axes in the X, Y, and Z directions and a drive axis for swinging a welding torch as a lightweight and compact welding device that is easy to move and prepare for welding. Patent Document 2 also shows that the motor is controlled based on the welding speed read from a shared memory to set the welding speed to a predetermined speed, and the welding swing control unit controls the motor for each welding layer in each area to swing the welding torch to an amplitude corresponding to the bottom width.

[0006] Furthermore, Patent Document 3 shows a portable automatic welding device that moves on a guide rail and has three orthogonal axes in the X, Y, and Z directions, plus a T-axis for tilting the welding torch. Patent Document 3 also shows that the area between two points where the groove shape is measured is divided into regions, the welding speed calculated at the front and back points is linearly interpolated to determine the welding conditions for each region, the oscillation conditions for each region are set according to the determined welding speed, and the welding torch is oscillated during welding. [Prior art documents] [Patent documents]

[0007] [Patent Document 1] JP 2013-202673 A [Patent Document 2] Special Publication No. 8-15665 [Patent Document 3] Patent Publication No. 2021-16881 Summary of the Invention [Problem to be solved by the invention]

[0008] However, in the weaving for vertical welding and horizontal welding in Patent Document 1, it is said that appropriate weld buildup can be obtained by applying complex weaving patterns such as sawtooth or rectangular patterns, and although such special weaving patterns can be easily realized by using a multi-joint robot with multiple degrees of freedom, it is impractical and difficult to apply an automatic welding device that includes a multi-joint robot to on-site welding like a portable welding robot, considering the weight of the device and installation time.

[0009] In addition, the welding devices in Patent Documents 2 and 3 use a swing mechanism dedicated to weaving or a movement mechanism that moves the welding torch in the groove width direction in a portable welding robot to perform weaving by reciprocating the welding torch during welding, but in either case, the weaving conditions are set according to the determined welding speed, and the welding torch is weaved during welding. In other words, since the weaving conditions differ for each determined welding speed, it is necessary to always manage the welding speed and the weaving conditions as a pair.

[0010] Here, Fig. 28(a) shows the weaving movement when the weaving cycle is appropriate for the determined welding speed. In this state, if the welding speed is increased, the gaps in the weaving pattern will widen as shown in Fig. 28(b), and the arc will not reach some areas in the gaps in the weaving pattern, which may cause insufficient penetration in the groove.

[0011] In addition, in weaving, a stop time may be set at both ends of the weaving so that sufficient penetration of the groove wall can be obtained. The purpose of setting a stop time at both ends of the weaving is to hold the welding arc at the stopped place to increase heat input and obtain sufficient penetration. However, in the portable welding robot described in Patent Documents 2 and 3, the welding torch moves in the direction of the weld line while staying at both ends of the weaving. Therefore, the welding arc, which is the heat input point, moves, and the original purpose cannot be achieved. Furthermore, if the welding speed increases, the gap in the weaving pattern will widen as shown in Figure 29, and there will be a place where the arc cannot reach in the gap of the weaving pattern, which raises concerns about insufficient penetration in the groove.

[0012] The above-mentioned worrying phenomena shown in Figure 28(b) and Figure 29 are all caused by the fact that the weaving and the movement in the weld line direction are not synchronized and move independently. To prevent such phenomena from occurring, weaving conditions such as cycle, width, and stop time must be managed for each determined welding speed. In addition, when the weld length becomes long and there are multiple measurement points for the groove shape that determines the welding speed, management becomes complicated and there is a risk of inaccurate welding conditions, including the weaving conditions.

[0013] The present invention has been made in consideration of the above-mentioned problems, and has an object to provide a weaving control method, a welding control device, a welding system, a welding method, and a weaving control program for obtaining good welding quality in various welding positions, such as flat welding, horizontal welding, and vertical welding, using a portable welding robot that moves on a guide rail. [Means for solving the problem]

[0014] The above object of the present invention is achieved by the following configuration [1] relating to a weaving control method. [1] A weaving control method for welding a workpiece having a groove using a portable welding robot that moves on a guide rail, comprising: A setting step of setting at least a condition of a weaving reference locus related to a reference distance for determining a weaving pattern; a speed condition calculation step of calculating a speed condition to be instructed to a robot movement mechanism that moves the portable welding robot, for each of a plurality of predetermined directional components, based on the weaving pattern determined based on the setting step; having A stop signal command and a start signal command issued immediately after issuing the stop signal or after a predetermined stop time has elapsed, for the speed conditions of each of the plurality of directional components calculated in the speed condition calculation step, are synchronized at least at the time of arrival of a weaving end. A weaving control method comprising:

[0015] The above object of the present invention can be achieved by the following configuration [2] relating to a welding control device. [2] A welding control device used for weaving control to weld a workpiece having a groove using a portable welding robot that moves on a guide rail, comprising: A setting step of setting at least a condition of a weaving reference locus related to a reference distance for determining a weaving pattern; a speed condition calculation step of calculating a speed condition to be instructed to a robot movement mechanism that moves the portable welding robot, for each of a plurality of predetermined directional components, based on the weaving pattern determined based on the setting step; having A function of synchronizing a stop signal command and a start signal command immediately after issuing the stop signal or after a predetermined stop time has elapsed for the speed conditions of each of the plurality of directional components calculated in the speed condition calculation step at least at the time of arrival of a weaving end. A welding control device characterized by:

[0016] The above object of the present invention can be achieved by the following configuration [3] relating to a welding system. [3] A welding system comprising the welding control device described in [2] above.

[0017] The above object of the present invention can be achieved by the welding method described below in [4]. [4] A welding method using the welding system described in [3] above.

[0018] The above object of the present invention can be achieved by the following configuration [5] relating to a weaving control program. [5] A weaving control program used for weaving control for welding a workpiece having a groove using a portable welding robot that moves on a guide rail, comprising: A setting step of setting at least a condition of a weaving reference locus related to a reference distance for determining a weaving pattern; a speed condition calculation step of calculating a speed condition to be instructed to a robot movement mechanism that moves the portable welding robot, for each of a plurality of predetermined directional components, based on the weaving pattern determined based on the setting step; having A function of synchronizing a stop signal command and a start signal command issued immediately after issuing the stop signal or after a predetermined stop time has elapsed, for the speed conditions of each of the plurality of directional components calculated in the speed condition calculation step, at least at the time of arrival of a weaving end. A weaving control program comprising: Effect of the Invention

[0019] According to the present invention, it is possible to provide a weaving control method, a welding control device, a welding system, a welding method, and a weaving control program for obtaining good welding quality in various welding positions, such as flat welding, horizontal welding, and vertical welding, using a portable welding robot that moves on a guide rail. [Brief description of the drawings]

[0020] [Figure 1]FIG. 1 is a schematic diagram of one embodiment of a welding system according to the present invention. [Diagram 2] FIG. 2 is a schematic side view of the portable welding robot shown in FIG. [Diagram 3] FIG. 3 is a perspective view of the portable welding robot shown in FIG. [Figure 4] FIG. 4 is an enlarged view of the approximate linear movement mechanism shown in FIG. [Diagram 5] FIG. 5 is a graph showing a reference speed setting waveform. [Figure 6] FIG. 6 is a schematic perspective view of a groove portion of a workpiece. [Figure 7] FIG. 7 is a schematic perspective view of a portable welding robot that uses straight guide rails for a groove that includes a curve. [Figure 8] FIG. 8 is a time chart showing the welding speed between the weld line position detection points. [Figure 9] FIG. 9 is a perspective view that typically shows a weaving pattern in flat welding. [Figure 10] FIG. 10(a) is a time chart of the weaving speed, and FIG. 10(b) is a time chart of the welding speed. [Figure 11] FIG. 11 is a graph showing a weaving pattern in the time chart shown in FIG. [Figure 12] FIG. 12 is a time chart of weaving with stop times set at both ends. [Figure 13] FIG. 13 is a graph showing a weaving pattern in the time chart shown in FIG. [Figure 14A] FIG. 14A is a perspective view showing a weaving pattern involving movements in the X, Y, and Z axis directions. [Figure 14B] FIG. 14B is a view seen from the arrow A in FIG. 14A. [Figure 15] FIG. 15 is a time chart of weaving involving movement in the X, Y, and Z axis directions. [Figure 16]FIG. 16 is a graph showing a weaving pattern in the time chart shown in FIG. [Figure 17] FIG. 17 is a schematic diagram of a weaving pattern in horizontal welding. [Figure 18] FIG. 18(a) is a time chart of the weaving speed for realizing the weaving pattern shown in FIG. 17, and FIG. 18(b) is a time chart of the welding speed for realizing the weaving pattern shown in FIG. [Figure 19] FIG. 19 is a schematic diagram of a sawtooth weaving pattern. [Figure 20] FIG. 20(a) is a time chart of the weaving speed for realizing the sawtooth weaving pattern shown in FIG. 19, and FIG. 20(b) is a time chart of the welding speed for realizing the sawtooth weaving pattern shown in FIG. 19. [Figure 21] FIG. 21 is a graph showing a sawtooth weaving pattern. [Figure 22] FIG. 22 is a perspective view of vertical welding. [Diagram 23] Figure 23(a) is a view of an example of a weaving pattern for vertical welding shown in Figure 22, Figure 23(b) is a view of another example of the weaving pattern, and Figure 23(c) is a view of yet another example of the weaving pattern, both viewed from the arrow B. [Figure 24] FIG. 24 is a time chart showing a weaving pattern involving movement in three axial directions, X, Y, and Z, and a welding speed and a weaving speed in each direction. [Diagram 25] FIG. 25 is a schematic diagram showing a state in which both open tips are welded by a combination of movement of the welding torch in the XA direction by the X-axis movement mechanism and movement of the welding torch in the XB direction by the welding torch rotation drive unit. [Figure 26] FIG. 26 is a schematic diagram showing a state in which the torch angle is changed without moving the position of the tip of the welding wire of the welding torch by combining movement of the welding torch in the XA direction by the X-axis movement mechanism and movement of the welding torch in the XB direction by the welding torch rotation drive unit. [Figure 27]FIG. 27 is a time chart for changing the torch angle shown in FIG. [Figure 28] FIG. 28(a) is a diagram showing weaving when the welding speed and weaving cycle are appropriate, and FIG. 28(b) is a diagram showing weaving when the welding speed is excessively high. [Figure 29] FIG. 29 is a diagram showing weaving when end stopping and the welding speed is excessive. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0021] Hereinafter, a welding system according to an embodiment of the present invention will be described with reference to the drawings. Note that this embodiment is an example of a case in which a portable welding robot is used, and the welding system of the present invention is not limited to the configuration of this embodiment.

[0022] <Welding system configuration> 1 is a schematic diagram showing the configuration of a welding system according to the present embodiment. As shown in FIG 1, the welding system 50 includes a portable welding robot 100, a feeder 300, a welding power source 400, a shielding gas supply source 500, and a control device 600.

[0023] [Control device] Control device 600 is connected to portable welding robot 100 via robot control cable 610, and to welding power source 400 via power supply control cable 620. Control device 600 has a data storage unit 601 that stores teaching data that predefines the operation pattern, welding start position, welding end position, welding conditions, weaving, etc. of portable welding robot 100, and sends commands to portable welding robot 100 and welding power source 400 based on this teaching data to control the operation of portable welding robot 100 and the welding conditions.

[0024] The control device 600 also includes a groove shape information calculation unit 602 that calculates groove shape information from detection data obtained by sensing, which will be described later, and a welding condition acquisition unit 603 that corrects and acquires the welding conditions of the teaching data based on the groove shape information. The groove shape information calculation unit 602 and the welding condition acquisition unit 603 constitute a control unit 604.

[0025] Furthermore, the control device 600 is formed by integrating a controller for teaching and manual operation of the portable welding robot 100 and a controller having other control functions. However, the control device 600 is not limited to this, and may be divided into a plurality of controllers according to their roles, such as a controller for teaching and a controller having other control functions, or the portable welding robot 100 may include the control device 600. In the present embodiment, signals are sent using the robot control cable 610 and the power supply control cable 620, but the present invention is not limited to this, and signals may be sent wirelessly. From the viewpoint of usability at the welding site, it is preferable to divide the controller into two controllers, a controller for teaching and manual operation of the portable welding robot 100 and a controller having other control functions.

[0026] [Welding power source] The welding power source 400, in response to a command from the control device 600, supplies a welding wire 211, which is a consumable electrode, and a workpiece W o By supplying power to the welding wire 211 and the workpiece W o An arc is generated between the welding power source 400 and the welding wire 211. Power from the welding power source 400 is sent to the wire feeder 300 via a power cable 410, and is then sent from the wire feeder 300 to the welding torch 200 via a conduit tube 420. As shown in FIG. 2, the power from the welding power source 400 is supplied to the welding wire 211 via a contact tip at the front end of the welding torch 200. The current during the welding operation may be DC or AC, and the waveform is not particularly important. Therefore, the current may be a pulse such as a square wave or a triangular wave.

[0027] In addition, the welding power source 400 is, for example, connected to the welding torch 200 side with the power cable 410 as a positive electrode and connected to the workpiece W with the power cable 430 as a negative electrode. o Note that this is the case when welding with reverse polarity. When welding with positive polarity, the power cable of the positive electrode is connected to the work W. o The power cable of the negative electrode is connected to the welding torch 200 side.

[0028] [Shielding gas supply source] The shielding gas supply source 500 is composed of a container filled with shielding gas, a valve, and other auxiliary members. The shielding gas is sent from the shielding gas supply source 500 to the feeder 300 via a gas tube 510. The shielding gas sent to the feeder 300 is sent to the welding torch 200 via a conduit tube 420. The shielding gas sent to the welding torch 200 flows inside the welding torch 200, is guided to the nozzle 210, and is ejected from the tip side of the welding torch 200. The shielding gas used in this embodiment may be, for example, argon (Ar), carbon dioxide (CO2), or a mixture thereof.

[0029] [Feeding device] The feeder 300 pays out the welding wire 211 and feeds it to the welding torch 200. The welding wire 211 fed by the feeder 300 is not particularly limited, and may be fed to the workpiece W. o The welding wire is selected according to the properties of the wire and the welding form, and for example, a solid wire or a flux-cored wire is used. The material of the welding wire is not particularly limited, and may be, for example, mild steel, stainless steel, aluminum, titanium, or other materials. The diameter of the welding wire is not particularly limited, but the preferred diameter in this embodiment is 1.6 mm at the upper limit and 0.9 mm at the lower limit.

[0030] In the conduit tube 420 according to this embodiment, a conductive path for functioning as a power cable is formed on the outer skin side of the tube, a protective tube for protecting the welding wire 211 is disposed inside the tube, and a flow path for the shielding gas is formed. However, the conduit tube 420 is not limited to this, and for example, a power supply cable and a hose for supplying the shielding gas may be bundled around a protective tube for feeding the welding wire 211 to the welding torch 200. Also, for example, the tube for feeding the welding wire 211 and the shielding gas and the power cable may be installed separately.

[0031] [Portable welding robot] 2 and 3, the portable welding robot 100 includes a guide rail 120, a robot body 110 that is installed on the guide rail 120 and moves along the guide rail 120, and a torch connection part 130 that is placed on the robot body 110. The robot body 110 is mainly composed of a main body part 112 that is installed on the guide rail 120, a fixed arm part 114 that is attached to the main body part 112, and a welding torch rotation drive part 116 that is attached to the fixed arm part 114 in a state that it can rotate in the direction of arrow R1.

[0032] 4, the torch connection part 130 is attached to the welding torch rotation drive part 116 via a sliding table 169 and a crank 170. The torch connection part 130 is equipped with a torch clamp 132 and a torch clamp 134 that fix the welding torch 200. In addition, the main body part 112 is provided with a cable clamp 150 that supports a conduit tube 420 that connects the feeding device 300 and the welding torch 200 on the side opposite to the side on which the welding torch 200 is attached.

[0033] In this embodiment, the work W o A voltage is applied between the workpiece W and the welding wire 211, and the welding wire 211 is oThe detection means is a touch sensor that senses the surface of the groove 10 by utilizing the voltage drop phenomenon that occurs when the surface of the groove 10 is touched. The detection means is not limited to the touch sensor of this embodiment, and an image sensor, a laser sensor, or a combination of these detection means may be used. However, it is preferable to use the touch sensor of this embodiment from the viewpoint of simplicity of the device configuration.

[0034] 2, the main body 112 of the robot main body 110 includes an X-axis movement mechanism 181 that moves the robot main body 110 along the guide rail 120 in the X-axis direction, which is perpendicular to the paper and corresponds to the direction of the weld line. The main body 112 also includes a Y-axis movement mechanism 182 that moves the fixed arm portion 114 relative to the main body 112 via the slide support portion 113 in the Y-axis direction, which is the width direction of the groove 10 perpendicular to the X-axis direction and the Z-axis direction. The main body 112 also includes a Z-axis movement mechanism 183 that moves the robot main body 110 in the depth direction of the groove 10 perpendicular to the X-axis direction.

[0035] Furthermore, as shown in FIG. 4, sliding table 169 to which torch connection part 130 is attached, crank 170, and welding torch rotation drive part 116 constitute an approximate straight line movement mechanism 180 that moves the tip of welding wire 211 along an approximate straight line.

[0036] Specifically, a crank 170 is fixed to a rotating shaft 168 of a motor (not shown) fixed to welding torch rotation drive unit 116, and a tip of the crank 170 is connected to one end of a sliding table 169 by a connecting pin 171. Sliding table 169 has a long groove 169a in the middle, and a fixing pin 172 fixed to welding torch rotation drive unit 116 is slidably fitted into long groove 169a.

[0037] As a result, when the crank 170 rotates around the rotation shaft 168 by a motor (not shown), the sliding table 169 rotates around the fixed pin 172 as a fulcrum, and moves along the long groove 169a while being guided by the fitted fixed pin 172. That is, the torch connection part 130 to which the welding torch 200 is attached drives the tip of the welding wire 211 along the approximate straight line shown by the imaginary line IL in FIG. 4 with respect to the X-axis direction while tilting the welding torch 200 by rotating the crank 170 as shown by the arrow R2 in FIG. 3 and FIG. 4. Note that, in this embodiment, the mechanisms for moving in the X-axis direction include the above-mentioned X-axis moving mechanism 181 and the approximate linear moving mechanism 180. Hereinafter, when these mechanisms are described separately, when moving in the X-axis direction by the X-axis moving mechanism 181, it will be referred to as the "XA-axis direction", and when moving in the X-axis direction by the approximate linear moving mechanism 180, it will be referred to as the "XB-axis direction". When it is not particularly important which mechanism to use, it will be described simply as the "X-axis direction".

[0038] Furthermore, welding torch rotation drive unit 116 is rotatably attached to fixed arm unit 114 as shown by arrow R1 in FIG. 2, and can be adjusted to an optimal angle and fixed therein.

[0039] As described above, the robot body 110 can drive the welding torch 200, which is its tip, with four degrees of freedom in three directions, i.e., the X-axis direction, the Y-axis direction, and the Z-axis direction, by the approximate linear movement mechanism 180, the X-axis movement mechanism 181, the Y-axis movement mechanism 182, and the Z-axis movement mechanism 183. However, the robot body 110 is not limited to this, and may be capable of being driven with any number of degrees of freedom depending on the application.

[0040] With the above-mentioned configuration, the tip of the welding wire 211 of the welding torch 200 attached to the torch connecting part 130 can be directed in any direction. That is, the robot body 110 can be driven in the X-axis direction on the guide rail 120. Also, the welding torch 200 can be driven in the Y-axis direction which is the width direction of the groove 10 or in the Z-axis direction which is the depth direction of the groove 10. Also, by driving the crank 170, the welding torch 200 can be tilted according to the construction situation, for example, to provide a forward angle or a backward angle.

[0041] A mounting member 140 such as a magnet is provided below the guide rail 120. The guide rail 120 is supported by the mounting member 140 so as to support the workpiece W. o The portable welding robot 100 is configured so as to be easily attached to and detached from the workpiece W. o When the portable welding robot 100 is set on the workpiece W, the operator holds the handles 160 on both sides of the portable welding robot 100 to move the portable welding robot 100 to the workpiece W. o It can be easily set on top.

[0042] <How to set the travel speed of each drive axis of a portable welding robot> A stepping motor is used for each drive shaft of X-axis movement mechanism 181, Y-axis movement mechanism 182, Z-axis movement mechanism 183, and approximate linear movement mechanism 180, which move welding torch 200 of portable welding robot 100 in the X-axis, Y-axis, or Z-axis directions. The rotating shaft of the stepping motor is coupled to a reducer, and a pinion is attached to the rotating shaft of the reducer in the movement mechanisms in the X-axis, Y-axis, and Z-axis directions.

[0043] In the XA-axis direction, the robot is driven in the XA-axis direction while meshing with a rack attached to the guide rail 120. In the Y-axis direction, the robot is driven in the Y-axis direction while meshing with a rack attached to the slide support part 113. Similarly, the robot is driven in the Z-axis direction while meshing with a rack attached to the slide support part for the Z-axis direction inside the portable welding robot 100.

[0044] In the XB axis direction, a crank 170 is attached to a rotating shaft 168 of a reducer of welding torch rotation drive unit 116, and the tip of welding wire 211 can be moved in the XB axis direction while tilting welding torch 200 by rotating crank 170. Welding torch rotation drive unit 116 can set the torch angle of welding torch 200, and can also set the moving speed and moving distance that the tip of welding wire 211 moves in the XB axis direction.

[0045] The process of the moving speed from start to stop in the X-axis, Y-axis and Z-axis directions is set with the acceleration and deceleration of the speed waveform shown in Fig. 5 based on the characteristics of the stepping motor. The set speed VH is the original moving speed, but an acceleration time Tsu1 and a deceleration time Tsu2 are provided before and after it, so that on the starting side, the stepping motor accelerates from the initial speed VL, which is the first speed setting value, to the set speed VH, which is the second speed setting value, and on the stopping side, the stepping motor decelerates from the set speed VH to the initial speed VL and stops. The moving time TH from the starting to the stopping includes the acceleration time Tsu1, the deceleration time Tsu2 and the period during which the stepping motor moves at the set speed VH in between, but the acceleration time Tsu1 and the deceleration time Tsu2 vary depending on the load and the set speed of each axis, and are generally several tens to several hundreds of milliseconds. The reason for setting the initial speed VL lower than the set speed VH is that if the stepping motor accelerates directly from a stopped state to the set speed VH, the stepping motor may not be able to keep up and may lose synchronism.

[0046] In addition, the molten pool that becomes the weld bead can be maintained in a stable state by being directly under the arc, which is the heat source, and a good weld bead can be formed. If the set speed VH exceeds the initial speed VL, and the welding speed, i.e., the moving speed of the arc, is suddenly changed to the set speed, the arc, which is the heat source, moves in a sudden motion before the base metal has sufficiently melted, so that the base metal does not melt sufficiently and the molten pool cannot exist directly under the arc, resulting in an irregular weld bead only in the area where the welding speed suddenly changed. To avoid this, when the moving speed of the arc is reached to the set speed VH, the moving speed of the arc is gradually accelerated in a sloped manner from the initial speed VL to the set speed VH, so that the formation of the molten pool follows the movement of the arc and the molten pool exists directly under the arc.

[0047] Therefore, when the set speed VH is equal to or lower than the initial speed VL, the acceleration time Tsu1 and the deceleration time Tsu2 are not necessary, and FIG. 5 is a rectangular shape starting from the set speed VH. The waveforms shown in FIG. 5 are treated as one unit, and are stacked to move in each direction. That is, each time the setting in FIG. 5 is repeated, the stop signal and the start signal are issued synchronously, and the welding torch 200 moves in the X-axis direction, the Y-axis direction, and the Z-axis direction while repeatedly starting and stopping. Note that the gradient of the speed change from the initial speed VL to the set speed VH, and the gradient of the speed change from the set speed VH to the initial speed VL, that is, the acceleration of these, are preferably constant values ​​within the range where there is no risk of stepping out as described above, and the acceleration time Tsu1 and the deceleration time Tsu2 are preferably determined based on the predetermined gradient.

[0048] [Weld line position detection point P n Obtaining welding conditions Figure 6 shows the workpiece W o 6 shows a perspective view of the groove portion of FIG. 6, in which the weld line direction, which is the longitudinal direction of the groove 10, includes not only straight lines but also curved lines, and further, is a schematic perspective view when welding the groove 10 in which the root gap GA changes in the width direction of the groove 10. Also, FIG. 7 is a schematic perspective view when a portable welding robot 100 is installed on a straight guide rail 120 for the groove 10 including curved lines as shown in FIG.

[0049] When welding the groove 10, a teaching program is created in which the operation of the portable welding robot 100 and the welding conditions are set in advance, and before welding begins, the welding conditions during welding are corrected or acquired using the portable welding robot 100 that moves along the guide rail 120. In detail, for example, based on an operation signal from the control device 600, the portable welding robot 100 is driven to start automatic sensing of the groove shape, groove shape information is calculated, and further the welding conditions are calculated to perform automatic gas shielded arc welding.

[0050] That is, in a setting step when creating or correcting a teaching program, at least the conditions of the weaving reference trajectory described later are set, and then groove shape information is calculated. In addition, in the stage of calculating the welding conditions, the calculation of the welding conditions includes at least a speed condition calculation step, and in this speed condition calculation step, the speed conditions to be instructed to each of the moving mechanisms 180, 181, 182 and 183 are calculated for each of a plurality of directional components to perform automatic gas-shielded arc welding.

[0051] Here, in this embodiment, the "weaving reference path condition" set in the setting step is a condition related to a reference distance for determining a weaving pattern, and in this embodiment, at least two pieces of information are included among the reference distance in the X-axis direction, the reference distance in the Y-axis direction, and the reference distance in the Z-axis direction. More specifically, as shown on the left in FIG. 24, the item indicating the reference distance in the X-axis direction is the pitch Pt described later, the item indicating the reference distance in the Y-axis direction is the weaving width YO on the Y-axis, and the item indicating the reference distance in the Z-axis direction is the weaving width ZO on the Z-axis. In this embodiment, the pitch Pt and the weaving width ZO are set in advance, and the setting value of the weaving width YO changes based on the gap width calculated by the groove shape information calculation process described later.

[0052] In addition to the condition of the weaving reference locus, the conditions set in the setting step include the condition of the stop time of the weaving end, which will be described later, the condition of the speed ratio G of the weaving round trip path, the condition of the shift amount for shifting an arbitrary position in an arbitrary direction, etc. The condition of the stop time of the weaving end may be set to a set value according to the position of the end stop, and it is preferable to set it separately, for example, as the stop time T1 of the weaving end and the stop time T2 of the other weaving end.

[0053] Further, the condition of the shift amount for shifting an arbitrary position in an arbitrary direction will be described in detail later, but in this embodiment, as shown in the left diagram of FIG. 24, the distance XO for shifting the position of the weaving end YO on the upper side with respect to the paper surface in the X-axis direction is set as the shift amount. If the weaving pattern determined by the condition of the weaving reference trajectory, that is, the trajectory shown by the solid line in the left diagram of FIG. 24, is set as the standard weaving pattern for convenience, a special sawtooth weaving pattern can be applied as shown by the trajectory shown by the dotted line in the diagram by shifting the position of the weaving end on the upper side with respect to the paper surface in the X-axis direction by a distance equivalent to the numerical value set as the shift amount XO from the standard weaving pattern. Note that this shift amount XO may be set as a fixed value in advance, or the set value may be changed each time, for example, based on the gap fluctuation before or during welding.

[0054] In the sensing process, the groove shape, plate thickness, start and end ends, etc. are sensed by the above-mentioned touch sensor.

[0055] In the sensing process, for example, as shown in FIG. 6, in the welding section from the welding start point 10s to the welding end point 10e of the groove 10, when the groove includes not only straight lines but also curves, the root gap GA also changes, and the groove shape differs from place to place, the cross-sectional shape of the groove 10, which is an inverted trapezoidal cross-sectional shape, is detected at the groove shape detection position F. n A plurality of sensing positions (F0, F2, . . . , F5), six in this embodiment, are provided as sensing positions.

[0056] In this embodiment, the groove shape detection position F n The intersection point between and the welding line WL is called the welding line position detection point P n (P0~P5). The weld line WL is the work W o This refers to the movement trajectory of the tip of welding wire 211 set at an arbitrary position in groove 10 above, and the tip of welding torch 200 weaves along the weld line WL, i.e., the X-axis direction, in the groove width direction, i.e., the Y-axis direction.

[0057] In detail, the groove shape detection position F closest to the welding start point 10s n The first groove shape detection position F s (F0), and the groove shape detection position F closest to the welding end point 10e n The second groove shape detection position F e As (F5), the portable welding robot 100 performs sensing using the touch sensor while moving on the guide rail 120. The position settings of the first groove shape detection position Fs and the second groove shape detection position Fe may be input in advance to the control device 600 by teaching or the like.

[0058] After the sensing process, each groove shape detection position F obtained in the sensing process n From the detection data of the groove cross-sectional shape in (F0 to F5), the groove angle, plate thickness, root gap GA, work end W e The distance L between the grooves is calculated. In addition, these calculation steps are hereinafter referred to as the "groove shape information calculation step". Then, each groove shape detection position F n Based on the groove shape calculated in (F0 to F5), each weld line detection point P n The welding conditions (P0 to P5) are calculated, and the welding conditions are corrected against the welding conditions acquired or preset in the control device 600 through a welding condition calculation process, and the welding conditions when actually performing welding are determined. n When the weld beads are layered under the welding conditions (P0 to P5), the number of layers of the weld beads in the groove and the number of passes are the same. nThe welding conditions (P0 to P5) include, for example, the welding current for each pass, the welding voltage, the welding speed, the target position of the tip of the welding wire of the welding torch, the weaving width, and the like.

[0059] [Weld line position detection point P n [How to control the movement speed (welding speed) in the X-axis direction during weaving between the workpieces] Next, the welding line position detection point P using the welding system 50 according to this embodiment n A method for controlling the welding speed during welding will now be described in detail. Weld line position detection point P n The welding speed of is found in the previous welding condition calculation process, and the adjacent weld line position detection point (P n-1 ,P n The welding speed between the adjacent weld line position detection points (P n-1 ,P n ) the distance traveled in the X-axis direction between n The pitch Pt, which is one of the elements related to the reference distance for determining the weaving pattern, is divided and changed in stages to detect the adjacent weld line position (P n-1 ,P n ) to complement the welding speed. This will be explained in detail next.

[0060] As shown in FIG. 3, the guide rail 120 is installed along the groove 10 to be welded, so the groove 10 is considered to be along the X-axis direction, and the welding speed and the moving speed in the X-axis direction are set to be the same. In other words, the adjacent weld line position detection point (P n-1 ,P n The welding speed at the weld line position detection point (P n-1 ,P n ) is the same as the moving speed in the X-axis direction at the time of the First, the adjacent weld line position detection point (P n-1 ,P n ) the distance traveled in the X-axis direction DX n is divided by a provisional pitch Pt' set in advance to obtain a provisional division number m' as shown in equation (1).

[0061]

number

[0062] Next, the provisional division number m' is rounded down to an integer, and ΔD is calculated using equation (2).

[0063]

number

[0064] Then, the correct pitch Pt is calculated using equation (3).

[0065]

number

[0066] In addition, the calculation here is based on the weld line position detection point (P n-1 ,P n ) the distance traveled in the X-axis direction DX n This means that the pitch Pt can be used to divide the weaving pattern into an integer number of divisions m without any fractions. The pitch Pt and number of divisions m obtained here are also units for determining the weaving conditions, as will be described later.

[0067] Next, the welding speed VX of the part divided by pitch Pt k , that is, the movement speed in the X-axis direction. As shown in equation (4), the weld line position detection point (P n-1 ,P n ) Welding speed (VXP n-1 ,VXP n ) is divided by the division number m to obtain the welding speed ΔVX, which is the increase or decrease for each pitch Pt.

[0068]

number

[0069] Using equation (4), the welding speed for each pitch Pt is given by equation (5).

[0070]

number

[0071] Here, k is an integer from 1 to m, and VX m =VXP n become.

[0072] From equation (5), the welding speed VX for each pitch Pt k is required, but the welding speed VX k Furthermore, since 1 / 2 of the pitch Pt is located at the weaving end during weaving, as described later, it is set to stop once. This is also a setting for determining the weaving conditions, which will be described later. The weld line position detection point (P n-1 ,P n ) is shown in Figure 8. As explained in Figure 5, the welding speed VX is controlled by controlling the movement speed in the X-axis direction, i.e., the welding speed, using the trapezoidal speed setting as a unit.

[0073] In other words, the weld line position detection point (P n-1 ,P n ) welding speed VX is the travel distance DX in the X-axis direction n The welding speed VX is changed stepwise by ΔVX with respect to the pitch Pt as a reference, and start and stop are repeated every 1 / 2 of the pitch Pt. In Fig. 6 of this embodiment, the welding speed VX is determined in the same manner as in Fig. 8 between adjacent weld line position detection points (P0, P1), (P1, P2), (P2, P3), (P3, P4), and (P4, P5), so that the welding speed VX is determined over the entire length of the groove 10. The pitch Pt is a value that affects the reciprocating period of weaving, which will be described later, and in this embodiment, the pitch Pt is set in the range of 5 to 10 mm, which is appropriate for filling the cross section of the groove 10 with weld metal, which is the purpose of weaving.

[0074] For example, in the above Patent Document 3, the welding speed is determined by linear interpolation using the welding speed between two points of the groove, and the welding speed is continuous between the two points of the groove. In general, including Patent Document 3, it is common knowledge that the welding speed is constant or continuously changed, but in this embodiment, starting and stopping are repeated every 1 / 2 of the pitch Pt as described above in accordance with the position of the weaving end. This control is a means for solving the problems shown in Figures 28(b) and 29.

[0075] During welding, the welding speed VX has an acceleration region of several tens to several hundreds of milliseconds until it reaches the set speed VH for each half of the pitch Pt. However, as described above, this acceleration does not affect the welding phenomenon and does not affect the welding quality.

[0076] [Weld line position detection point P n How to control the weaving pattern between In the control device 600, each welding line detection point P n The welding conditions are calculated, and for example, the target position and the weaving width are also determined. The purpose of the weaving action is to fill the cross section of the groove 10 with weld metal by moving the robot body 110 in the X-axis direction on the guide rail 120 while welding and swinging the welding torch in the Y-axis direction or the Z-axis direction. Since the weaving width item is an important element of weaving, it is preferable that at least one of the weaving widths in the Y-axis direction and the Z-axis direction is determined to meet this purpose.

[0077] Next, the welding line position detection point P n A method for controlling the weaving pattern between the wires will now be described.

[0078] <Basic control method> First, the basic control method will be explained using flat welding as an example. Here, the weaving control method will be explained in which the weaving end is located at pitch Pt / 2 and the welding torch moves in two directions, the X-axis direction and the Y-axis direction.

[0079] Figure 9 shows the adjacent weld line position detection points (P n-1 ,P n 10. The welding torch makes one round trip in the groove 10 at a pitch Pt in the X-axis direction. That is, the weaving is repeated by going to the weaving end located at Pt / 2 on the forward path and to the other weaving end located at the next Pt / 2 on the return path. The weaving movement speed in the X-axis direction is the welding speed VX shown in FIG. k According to the setting of (k is 1, 2, 3, 4, m), the robot body 110 runs on the rail in the X-axis direction, and the moving speed in the Y-axis direction, i.e., the weaving speed, is the weaving speed VYA k and VYB k According to the setting of (k is 1, 2, 3, 4, m), the weaving pattern UL in FIG. 9 is drawn.

[0080] The weaving width at this time is determined by the equation (7) described later, and the weld line position detection point P n-1 At the start of the weaving, the weld line position detection point P n So the weaving width is YO m (=YOP n This movement ends at the weld line position detection point (P n-1 ,P n ) calculated by the weaving width (YOP n-1 ,YOP n The weaving width is increased or decreased by ΔYO, which is the difference between the weaving width (YOP) and the number of divisions m. n-1 ,YOP n ) is controlled to complement each other.

[0081] More detailed explanation will be given. n-1 ,P n ) Weaving width (YOP n-1 ,YOP n The weaving width increase / decrease ΔYO between the two is expressed by the following formula (6).

[0082]

number

[0083] Therefore, the weld line position detection point (P n-1 ,P n The weaving width YO between the two is expressed by the following formula (7).

[0084]

number

[0085] Here, k is an integer from 1 to m, and from formulas (6) and (7), YO m =YOP n become.

[0086] That is, equation (7) is the weld line position detection point (P n-1 ,P n ) is divided into m divisions, and in each divided area, the weaving width YO is determined by this formula (7). Note that the division number m is an integer used to set the welding speed VX.

[0087] In this embodiment, an arbitrary moving distance in the X-axis direction, that is, more specifically, a weld line position detection point (P n-1 ,P n ) by dividing the distance between the welding points by the number of divisions m, the welding speed is VX k and weaving speed VY k The movement of the welding torch is controlled by synchronizing the above. The time TX for the welding torch to move a distance of the pitch Pt in the X-axis direction is k is the welding speed VX in equation (5) set in that region. k Using this, we obtain the following equations (8) to (10).

[0088]

number

[0089]

number

[0090]

number

[0091] Equations (9) and (10) are divided into half the time, that is, the time during which the welding torch moves in the X-axis direction by 1 / 2 the pitch Pt, which correspond to the forward and backward weaving times described below.

[0092] In addition, the speed at which the welding torch moves in the X-axis direction by half the pitch Pt, that is, the moving speed VXA in the X-axis direction on the outward path k , and the travel speed in the X-axis direction on the return trip VXB k When expressed so as to correspond to equations (9) and (10), the following equations (11) and (12) are obtained.

[0093]

number

[0094]

number

[0095] On the other hand, since the welding torch makes one reciprocating movement in the Y-axis direction by the weaving width YO, the moving speed in the Y-axis direction at that time, i.e., the weaving speed, will be expressed separately for the forward and backward movements described above. The time it takes for the welding torch to weave in the forward direction is the same as the time it takes for the welding torch to move in the X-axis direction by 1 / 2 the pitch Pt. The time it takes for the welding torch to weave in the backward direction is also the same as the time it takes for the welding torch to move in the X-axis direction by 1 / 2 the pitch Pt. Each time is calculated from equations (9) and (10), and the weaving width YO k Since is calculated by equation (7), the weaving speed is expressed by the following equations (13) and (14).

[0096]

number

[0097]

number

[0098] Note that equation (13) represents the weaving speed on the outward path, and equation (14) represents the weaving speed on the return path with the sign reversed.

[0099] FIG. 10 shows a time chart of the weaving speed VY and the welding speed VX calculated from equations (5), (8), (9), (10), (11), (12), (13), and (14), and FIG. 11 shows the weaving pattern of the welding torch at that time.

[0100] As shown in Fig. 10, both the welding speed VX and the weaving speed VY are controlled by this combination, with the trapezoidal speed setting explained in Fig. 5 as a unit. Also, at times 0 to 8 in the figure, the welding speed VX and the weaving speed VY stop simultaneously and then start moving again at the same time. In other words, the welding torch weaves in synchronization with the start and stop of the welding speed VX, so that the weaving speed VY also starts and stops at the same timing. Fig. 11 shows the weaving trajectory at this time. The positions of the welding torch at times 0 to 8 in the circled numbers in Fig. 10 are the positions of the circled numbers 0 to 8 in Fig. 11.

[0101] 11, the welding torch is weaved by repeating a forward movement of Pt / 2 and a return movement of Pt / 2 at a pitch Pt in the X-axis direction. In other words, in this embodiment, the weaving pattern is determined by the pitch Pt in the X-axis direction, regardless of the welding speed VX.

[0102] 28(b), that is, the problem that the weaving cycle unintentionally widens due to the influence of the welding speed VX, and there is a place between the weavings where the arc does not reach, resulting in insufficient penetration in the groove, is eliminated. In this embodiment, the welding torch can be moved to a desired position, on a desired trajectory, and at a desired time to perform weaving without depending on the welding speed VX, so that the original purpose of filling the cross section of the groove 10 with weld metal can be efficiently performed, and as a result, excellent welding quality can be obtained.

[0103] <How to control the stop time on both ends> Furthermore, in weaving, a stop time may be provided at both ends of the weaving (hereinafter, the stop time at both ends of the weaving may also be simply referred to as "stop time") so that sufficient penetration of the groove wall can be obtained. The control method for stopping at both ends in this embodiment will be described next, still taking flat welding as an example.

[0104] In FIG. 11, the stop time at the upper end of the weaving, i.e., circled numbers 1, 3, 5, and 7, is T1, and the stop time at the lower end, i.e., circled numbers 2, 4, 6, and 8, is T2. As described above, in consideration of the problem-solving of the present invention, the time for the welding torch to advance by pitch Pt in the X-axis direction must always remain constant, regardless of whether there is a stop time at both ends of the weaving. This is because the weld line position detection point (P n-1 ,P n ) was not changed, and the welding line position detection point (P n-1 ,P n Therefore, the time TY for the welding torch to make one round trip across the weaving width YO in the Y-axis direction when there is a stop time at the weaving end is replaced by the following formula (15) obtained by subtracting T1 and T2 from formula (8).

[0105]

number

[0106] Here, k is an integer from 1 to m. The welding speed VX must be increased by the amount of the stop times T1 and T2, and the welding speed VX can be calculated using equation (15) and equations (9), (10), (11), and (12).

[0107] On the other hand, the time TY for one round trip of the weaving width YO becomes shorter, and the weaving speed becomes faster accordingly. The weaving speed VY at that time can be calculated similarly using equation (15) and also from equations (9), (10), (13), and (14).

[0108] Figure 12 shows a time chart in which stop times at both ends are set. In the figure, even though there are stop times indicated by the circled numbers 1'→1, 2'→2,...8'→8, as in the case of Figure 10, the welding speed VX and weaving speed VY repeat synchronized start and stop movements. The weaving pattern in this case is shown in Figure 13. The position of the welding torch at the time indicated by the circled numbers in Figure 12 is the position indicated by the circled numbers in Figure 13. There are stop times T1 and T2 at both ends of the weaving, but the weaving pattern is the same as Figure 11, which has no stop times. During the stop times, the welding torch is controlled so that it remains at both ends of the weaving without moving.

[0109] This eliminates the issue described in Figure 29, that is, even if the welding torch moves in the Y-axis direction in the direction of the weld line while stopping at both ends of the weaving based on the set stopping time, the weaving interval in the X-axis direction will widen due to the influence of the welding speed, and there will be areas at the weaving interval that the arc cannot reach, which will cause concerns about insufficient penetration in the groove.

[0110] In this embodiment, regardless of whether there is a stop time at both ends of the weaving, and regardless of the welding speed, the weaving pattern remains constant, and the welding torch can be moved to the desired position, on the desired trajectory, and at the desired time, so that the original purpose of filling the cross section of the groove 10 with weld metal can be efficiently achieved.

[0111] <Method for controlling weaving involving movement in the X, Y, and Z axis directions> In the back-up welding method in which an insulating material such as ceramic is attached to the back surface of the groove and a weld bead is also formed on the back side, in order to surely form the weld bead on the back surface side of the groove, that is, the back bead, it is conceivable to control the weaving so as to obtain good penetration at the center of the groove.

[0112] In the present embodiment, as an example, in addition to the basic control method of the weaving involving movement in the X-axis direction and the Y-axis direction described above, the weaving can be controlled so that the welding torch moves in the Z-axis direction, that is, in the groove depth direction, at the center of the weaving so as to promote the penetration at the center of the groove. The method for controlling the weaving involving movement in the X, Y, and Z axis directions will be described below.

[0113] Figures 14A and 14B show the weaving pattern in the method for controlling the weaving involving movement in the X, Y, and Z axis directions in which the width of the weaving in the Z-axis direction, which is the groove plate thickness direction, is added to the weaving in the Y-axis direction described in the basic control method.

[0114] As described above, when performing back-up welding as an example, the width ZO of the weaving in the groove plate thickness direction is set. The welding torch makes one round trip of the weaving width YO in the Y-axis direction while moving in the X-axis direction with a pitch Pt. Further, in the Z-axis direction, the weaving is performed such that it makes one round trip during the forward path of the weaving in the Y-axis direction and one round trip during the return path. As shown in Figure 14A, the numbers with circles 0 → 1’’ → 1 → 2’’ → 2 are the trajectories of the movement of the welding torch in the X-axis direction with a pitch Pt. Thereafter, this is repeated for each pitch Pt, and the robot body 110 travels on the guide rail in the X-axis direction with the welding speed VX set in Figure 8, and the weaving pattern UL is drawn.

[0115] The weaving speed VZ in the Z-axis direction is set by setting the weaving width ZO and becomes the formulas (16) and (17).

[0116]

number

[0117]

number

[0118] Here, k is an integer between 1 and m. Note that equation (16) is the weaving speed VZ in the Z-axis direction, and TA k can be obtained from equation (9). Equation (17) is the weaving speed VZ of the return path with the sign reversed, and TB in the equation k can be calculated from equation (10). Fig. 15 shows a time chart of weaving with movement in the three axial directions of X, Y, and Z. The welding speed VX shown in the figure can be calculated from equations (11) and (12), the weaving speed VY from equations (13) and (14), and the weaving speed VZ from equations (16) and (17).

[0119] The circled numbers 0 to 8 in the figure are the same time numbers as those in Figure 10 shown in the basic control method. In the figure, the circled numbers 1'' to 8'' represent the time when the welding torch is located at the weaving end in the Z-axis direction. At both ends of the weaving in the Y-axis direction as well as at the weaving end in the Z-axis direction, the movement speeds in the X, Y, and Z directions of each drive axis are controlled so that the start and stop are synchronized.

[0120] The weaving pattern at this time is shown in Figure 16. The welding torch positions at the circled numbers shown in Figure 15 are indicated by the same circled numbers in Figure 16. These circled numbers are the same as the positions of the circled numbers in Figure 14A. In this embodiment, as with the basic control method, even in weaving involving movement in the three axial directions of X, Y, and Z, it is possible to weave by reliably moving the welding torch to a targeted position, on a targeted trajectory, and at a targeted time without being affected by the welding speed VX. As explained above, in weaving involving movement in the three directions of the X, Y, and Z axes, a stop time can also be set at both ends of the weaving in the Y axis direction. Furthermore, a stop time can also be set at the ends of the weaving in the Z axis direction in the same way as a stop time is set at both ends of the weaving in the Y axis direction.

[0121] [How to control the reciprocating weaving speed] Horizontal welding using the portable welding robot 100 is performed on the workpiece W shown in FIG. o The portable welding robot 100 and the workpiece W are vertically set. o Since the positional relationship does not change, the weaving settings for flat welding can be used as is, and the basic control method, the control method for the stop time at both ends, and the weaving control method involving movement in the X, Y, and Z directions can be applied.

[0122] A characteristic of horizontal welding is that the welding wire and the workpiece W are melted by the arc. o The molten metal in the weld joint will sag under the influence of gravity, making it impossible to form a proper weld bead shape and making it impossible to produce a good welded joint. One possible solution to this problem is to change the reciprocating weaving speed to suppress the molten metal from sagging, and to use the arc to push the molten metal upward. In other words, it is necessary to control the weaving speed during the reciprocating weaving.

[0123] Next, the present embodiment will be described with respect to a method for controlling the reciprocating weaving speed in horizontal welding as an example. Note that, as described above, the control of the reciprocating weaving speed is particularly effective for horizontal welding, so the present embodiment will be described with respect to the case of horizontal welding as an example, but the present embodiment is not limited to horizontal welding and may be applied to various welding positions.

[0124] <Effective method for controlling reciprocating weaving speed in horizontal welding> FIG. 17 is a schematic diagram showing a weaving pattern in horizontal welding. As described above, in horizontal welding, the molten metal is affected by gravity and droops to the positive side of the Y-axis direction in the figure. On the other hand, the welding torch oscillates up and down in the groove by weaving, and when the welding torch moves to the lower side of the groove, that is, on the positive side of the Y-axis direction, in the direction in which gravity acts, there is a risk of promoting the drooping of the molten metal. Therefore, when the welding torch moves to the lower side of the groove, it is moved quickly to quickly move toward the lower end stop position of the weaving, and when the welding torch moves to the upper side of the groove, that is, on the negative side of the Y-axis direction, in the opposite direction in which gravity acts, it is moved slowly to move in a manner that aims to push up the drooping molten metal with the arc. A weaving control method for changing the weaving movement speed between the forward and backward weaving paths will be described.

[0125] When the weaving speed is the same in the forward and backward weaving passes, it is shown by equations (13) and (14) in the basic control method shown above. In this embodiment shown in Fig. 17, the weaving speed is controlled by setting a weaving speed ratio in the forward weaving pass, i.e., the movement toward the positive side in the Y-axis direction, and in the backward weaving pass, i.e., the movement toward the negative side in the Y-axis direction. If the weaving speed ratio is G, the relationship shown in equation (18) is obtained.

[0126]

number

[0127] Here, VYA k is the weaving speed on the outward trip, VYB k indicates the return weaving speed, and k is an integer from 1 to m. This equation (18) expresses the return weaving speed VYB k is the weaving speed VYA k This indicates that it moves at G times the speed of the magnet.

[0128] In this way, even if the reciprocating weaving speed is changed, the time TX for the welding torch to advance by the pitch Pt in the X-axis direction must not change. This is because the weld line position detection point (P n-1 ,P n This is to prevent the welding time between the weaving points from changing. Therefore, it is necessary to control the travel time of the weaving in the forward and backward directions in accordance with the increase or decrease in the weaving speed while maintaining the time TX.

[0129] In other words, if the time required for the welding torch to complete the movement of the weaving width YO on the outward path is TA, and the time required for the return path is TB, then the relationship between equations (19) and (20) is satisfied.

[0130]

number

[0131]

number

[0132] Here, k is an integer from 1 to m. k can be calculated from equation (8).

[0133] The weaving speeds in the forward and backward directions are calculated by dividing the weaving width YO by the times in equations (19) and (20), respectively, to obtain the following equations (21) and (22).

[0134]

number

[0135]

number

[0136] In equation (21), VYA is the weaving speed in the positive direction of the Y axis, and VYB in equation (22) is the weaving speed in the negative direction of the Y axis. k can be calculated from equation (7).

[0137] Similarly, the speed at which the welding torch moves the pitch Pt in the X-axis direction is divided into the forward and backward parts of the weaving in the Y-axis direction and 1 / 2 of the pitch Pt is divided by equations (19) and (20), resulting in the following equations (23) and (24).

[0138]

number

[0139]

number

[0140] Here, k is an integer from 1 to m. Note that VXA in formula (23) is the moving speed in the X-axis direction when the welding torch moves the weaving width YO to the positive side of the Y-axis direction on the outward path, and VXB in formula (24) is the moving speed in the X-axis direction when the welding torch moves the weaving width YO to the negative side of the Y-axis direction on the return path.

[0141] Figure 18 shows equations (19) to (24) in the form of a time chart. As with the basic control method for flat welding, the start and stop timing in the X and Y axis directions are synchronized at times indicated by circled numbers 0 to 8 in the diagram, and this control method changes the weaving speed VY and welding speed VX while maintaining the time TX that it takes the welding torch to advance by pitch Pt in the X axis direction, depending on the speed ratio G of the weaving forward and backward passes. Although the welding speed VX changes within the pitch Pt, the weld line position detection point (P n-1 ,P n ) does not change, and the distance DX does not change either, so the overall welding speed VX does not change.

[0142] The weaving pattern at this time is the same as that shown in Fig. 11 for the basic control method for flat welding. In this embodiment, even if the weaving speed is changed as described above, it is possible to weave by reliably moving the welding torch to the desired position, on the desired trajectory, and at the desired time, just like the basic control method.

[0143] <Special weaving pattern control method> As mentioned above, the characteristic of horizontal welding is that the welding wire and the workpiece W melted by the arc are o The molten metal in the welding process will begin to sag under the influence of gravity, making it difficult to obtain an appropriate weld bead shape and resulting in a risk of failing to obtain a good welded joint. As a countermeasure to this, we have previously shown a weaving control method in which the reciprocating weaving speed is changed to suppress the sagging of the molten metal and the sagging molten metal is pushed up by the arc.

[0144] Furthermore, it is possible to change the weaving pattern to a special trajectory and aim to push up the drooping molten metal with the arc. Therefore, next, a method for controlling the special weaving pattern will be described in this embodiment, taking a sawtooth weaving pattern as an example of the special weaving pattern. Note that the control of the special weaving pattern is not limited to horizontal welding, and may be used for various welding positions.

[0145] 19 shows a schematic perspective view of a special weaving pattern that is effective in horizontal welding. The welding torch is moved in a sawtooth shape in the groove 10, and the molten metal can be properly filled into the cross section of the groove 10. The above-mentioned Patent Document 1 also shows that the sawtooth weaving pattern can be realized by a welding device using a multi-joint robot, but in this embodiment, the sawtooth weaving pattern is realized by combining the drive in the X-axis direction and the Y-axis direction in the portable welding robot 100.

[0146] The sawtooth weaving pattern in this embodiment can be created by shifting the upper ends of the weaving patterns shown in the basic control method, indicated by circled numbers 1, 3, 5, and 7 in Fig. 11, in the X-axis direction. The amount of shift at this time is set as XO.

[0147] In this control method, the weaving width, time, and speed of the welding torch in the Y-axis direction are the same as those shown in the basic control method, and the weaving width is calculated from equation (7), the weaving time from equations (9) and (10), and the weaving speed from equations (13) and (14).

[0148] Meanwhile, the movement distance in the X-axis direction is first 1 / 2 the pitch Pt plus the shift amount XO while the welding torch moves on the outward weaving path. Conversely, while the welding torch moves on the return weaving path, it has already moved an extra shift amount XO in the X-axis direction instead of 1 / 2 the pitch Pt, so it needs to move back by the shift amount XO. From these relationships, the movement speed in the X-axis direction at 1 / 2 the pitch Pt can be calculated as shown in the following formulas (25) and (26).

[0149]

number

[0150]

number

[0151] Here, VXA in formula (25) is the moving speed in the X-axis direction when the welding torch moves in the weaving forward path. Also, VXB in formula (26) is the moving speed in the X-axis direction when the welding torch moves in the weaving backward path. TA in the formula k From equation (9), TB k can be obtained from formula (10), where k is an integer from 1 to m.

[0152] Figure 20 shows a time chart using equations (13), (14), (25), and (26), and the weaving pattern at this time is shown in Figure 21. The circled numbers in Figure 20 indicate the times when the start and stop in the X-axis and Y-axis directions are synchronized, just like in Figure 10 for basic control, and the position of the welding torch at that time corresponds to the position with the same circled number in Figure 21 and Figure 19.

[0153] Although it varies depending on the value of the shift amount XO, as can be seen from FIG. 20, the speed in the X-axis direction when the welding torch moves on the return path of the weaving is negative. In other words, this indicates the movement of the welding torch returning in the opposite direction to the welding direction. By performing this movement, weaving with a sawtooth trajectory is performed, as can be seen from the weaving pattern in FIG. 21. The triangles that form the sawtooth shape, that is, the shape formed by the circled numbers 0, 1, and 2, circled numbers 2, 3, and 4, circled numbers 4, 5, and 6, and circled numbers 6, 7, and 8 in the figure, can be changed by the value of the shift amount XO. Of course, there are settings where the welding speed VX is negative within the pitch Pt, but the welding line position detection point (P n-1 ,P n ) does not change, and the distance DX does not change either, so overall, the welding speed VX does not change. In this embodiment, even when such sawtooth weaving is performed, the welding torch can be controlled at a targeted position, on a targeted trajectory, and at a targeted time.

[0154] [Effective weaving pattern control method for vertical welding] A perspective view of vertical welding using the portable welding robot 100 is shown in FIG. o Since the positional relationship with the groove 10 is the same as that shown in Figure 3 for flat welding, the weaving settings for flat welding can be used as is, and the basic control method, the control method for the stop time at both ends, and the weaving control method involving movement in the X, Y, and Z directions can be applied.

[0155] Fig. 23 shows the weaving pattern for vertical welding in this embodiment. Fig. 23(a), (b) and (c) are views seen from viewpoint B in Fig. 22, and show the weaving pattern UL by the basic control, the control of the stop time at both ends and the weaving control involving the movement in the three axis directions of X, Y and Z.

[0156] In addition, in vertical welding, the molten pool made of molten metal tends to drip to the outside of the groove, which is the negative side in the Z-axis direction in the figure, and there are cases where the heat input to the wall of the groove 10 is small and penetration is insufficient. In this case, the welding torch can be weaved along the wall of the groove 10 so that both side walls of the groove 10 can be easily penetrated. This can be achieved by applying a weaving control method involving movement in the X, Y, and Z three-axis directions, as shown in Figure 23(c), and setting two stop positions in the Z-axis direction. Furthermore, a stop time can be set for each stop position.

[0157] FIG. 24 collectively shows the relationship between the weaving pattern of the weaving control involving movements in the three axial directions of X, Y and Z, as described above, and the welding speed VX and the weaving speeds VY and VZ.

[0158] [Weaving control method using approximate linear movement mechanism] Incidentally, portable welding robot 100 of this embodiment has approximately linear movement mechanism 180 (see FIG. 4) that can drive the tip of welding wire 211 approximately linearly in the X-axis direction while tilting welding torch 200. Here, the movement direction of portable welding robot 100 along guide rail 120 by the X-axis movement mechanism will be described as an XA direction, and the movement direction of welding torch 200 by approximately linear movement mechanism 180 will be described as an XB direction.

[0159] When there are face plates such as ceramic tabs or steel tabs at the start and end of the groove to block the molten pool, the welding torch 200 is tilted in the longitudinal direction of the groove using the approximate linear movement mechanism 180 so that the tip of the welding wire faces the joint corner between the base material and the face plate, thereby eliminating the remaining weld at the tip of the groove.

[0160] That is, as shown in FIG. 25, when the face plate 350 is on the surface of the welding start point 10s, the welding point of the welding torch 200, which is tilted automatically or manually, is set to the groove start end as shown by the circled number 1 in the figure, and groove welding is started, and the tip of the welding wire is moved in the XB direction by the approximate linear movement mechanism 180, and the inclination of the welding torch 200 is returned until the appropriate welding torch angle is reached as shown by the circled number 2 in the figure. When the appropriate welding torch angle is reached, the welding is continued in the XA direction using the X-axis movement mechanism until just before the groove end as shown by the circled number 3. The welding torch 200 is again tilted by the approximate linear movement mechanism 180 to automatically weld to the groove end as shown by the circled number 4. By such movement of the tip of the welding wire 211 in the XB direction, the same weaving control can be achieved even if it is replaced with the movement in the XA direction by the X-axis movement mechanism described above. In addition, by making the movement speed in the XA direction and the XB direction the same and reversing only the movement direction, a method for controlling the rotation of the welding torch becomes possible in which the torch angle of welding torch 200 is controlled and rotated without substantially changing the position of the tip of welding wire 211.

[0161] <Welding torch rotation control method> 26 shows a schematic diagram of the movement of the welding torch when the torch angle of the welding torch is controlled and rotated by making the moving speed in the XA direction and the XB direction the same and the moving direction the opposite direction. This allows welding torch 200 to rotate with almost no change in the position of the tip of welding wire 211. For example, when welding with the welding torch shown by θ3 in the figure toward the right on the page at a forward angle, when continuously turning back from the welding end, this rotation control method can be applied to change the torch angle of the welding torch to the forward angle in the welding direction shown by θ3' in the figure without changing the tip position of welding wire 211 at the welding end, and continuous welding can be performed as is.

[0162] The time chart for this is shown in Figure 27. In the XA direction, starting and stopping are repeated at intervals of time Tθ with a setting of speed Vθ. In the XB direction, by repeating movement in the opposite direction at the same interval as the XA direction with a negative speed Vθ so as to cancel out the movement in the XA direction, the movements in the XA and XB directions are offset, and welding torch 200 can be rotated while changing the torch angle without changing the position of the tip of the welding wire. The speed Vθ and time Tθ are set within a range that does not affect welding.

[0163] The present invention is not limited to the above-described embodiment, and modifications and improvements can be made as appropriate.

[0164] As described above, the present specification discloses the following:

[0165] (1) A weaving control method for welding a workpiece having a groove using a portable welding robot that moves on a guide rail, comprising: A setting step of setting at least a condition of a weaving reference locus related to a reference distance for determining a weaving pattern; a speed condition calculation step of calculating a speed condition to be instructed to a robot movement mechanism that moves the portable welding robot, for each of a plurality of predetermined directional components, based on the weaving pattern determined based on the setting step; having A stop signal command and a start signal command issued immediately after issuing the stop signal or after a predetermined stop time has elapsed, for the speed conditions of each of the plurality of directional components calculated in the speed condition calculation step, are synchronized at least at the time of arrival of a weaving end. A weaving control method comprising: According to this configuration, good welding quality can be obtained in various welding positions, such as flat welding, horizontal welding, and vertical welding, using a portable welding robot that moves on a guide rail.

[0166] (2) The directional component is selected from at least two of the weld line direction of the workpiece, the groove width direction perpendicular to the weld line direction, and the groove depth direction perpendicular to each of the weld line direction and the groove width direction. The weaving control method according to (1). According to this configuration, the welding torch can be weaving controlled in the groove width direction perpendicular to the weld line direction and in the groove depth direction perpendicular to both the weld line direction and the groove width direction.

[0167] (3) The robot movement mechanism includes an X-axis movement mechanism that moves the portable welding robot along the guide rail as a mechanism for moving the portable welding robot in the weld line direction, The robot moving mechanism includes a Y-axis moving mechanism and a Z-axis moving mechanism provided on the portable welding robot as mechanisms for moving the portable welding robot in the groove width direction and the groove depth direction, (2) A weaving control method. With this configuration, the welding torch can be moved in three axial directions.

[0168] (4) The mechanism for moving the portable welding robot in the weld line direction further includes an approximate linear movement mechanism provided on the portable welding robot. (3) A weaving control method according to the above. According to this configuration, the welding torch can be further moved in the weld line direction by the approximate linear movement mechanism.

[0169] (5) When the speed condition for each directional component includes a first speed setting value VL and a second speed setting value VH that is greater than the first speed setting value VL and varies for each weaving width, a speed condition process in which, in the speed condition from the start signal to the issuance of the stop signal, the first speed setting value VL is set after the start signal, the second speed setting value VH is set after the first speed setting value VL, the first speed setting value VL is set again after the second speed setting value VH, and the stop signal is set after the first speed setting value VL that has been set again; Repeated every time the start signal is issued. The weaving control method according to any one of (1) to (4). According to this configuration, when the drive sources of the movement mechanisms that move the welding torch in the X-axis direction, the Y-axis direction, and the Z-axis direction are configured with stepping motors, it is possible to prevent the stepping motors from losing synchronization.

[0170] (6) In the case where a period from the first speed setting value VL to the second speed setting value VH is defined as a rise period and a period from the second speed setting value VH to the first speed setting value VL again is defined as a fall period, the absolute value of the slope of the speed condition in each of the rising period and the falling period is a fixed value; (5) A weaving control method according to the above. This configuration prevents the stepping motor from losing synchronism and ensures stable operation. Also, the formation of the molten pool can follow the movement of the arc even during the rise and fall periods, and the molten pool can be kept directly below the arc, resulting in the formation of a good weld bead.

[0171] (7) The condition of the weaving reference locus includes, as the reference distance for determining the weaving pattern, a pitch Pt which is a distance between adjacent weaving ends on one side of a weld center line. The weaving control method according to any one of (2) to (4). According to this configuration, the weaving reference locus can be determined using the pitch Pt as the reference distance.

[0172] (8) determining the weaving reference trajectory so that the weaving end is located at Pt / 2, which is 1 / 2 of Pt; (7) A weaving control method according to the above. According to this configuration, the outward and return paths of the weaving can be set symmetrically.

[0173] (9) In the case where the stop signal command and the start signal command are provided at a position other than the weaving end, The stop signal command and the start signal command are provided between the weaving end and Pt / 2. (8) A weaving control method according to the above. According to this configuration, it is possible to weave along the wall of the groove, which is effective for producing a good joint in vertical welding.

[0174] (10) The condition of the weaving reference trajectory is A shift amount set to shift the position of the weaving end on one side located at Pt / 2 has at least one directional component. A weaving control method according to (8) or (9). This configuration allows a sawtooth weaving pattern to be formed.

[0175] (11) The directional component for setting the shift amount is at least the weld line direction, Shifting the position of the weaving end in the welding progress direction in the weld line direction; The weaving control method according to (10). This configuration allows a sawtooth weaving pattern to be formed.

[0176] (12) When changing the torch angle while the welding is stopped or during the welding, The robot movement mechanism includes an X-axis movement mechanism that moves the portable welding robot along the guide rail, and an approximate linear movement mechanism provided on the portable welding robot, as a mechanism for moving the portable welding robot in the weld line direction, a moving speed of the portable welding robot in the weld line direction is controlled by a combination of a moving speed based on the X-axis moving mechanism and a moving speed based on the approximate linear moving mechanism; The weaving control method according to any one of (2) to (4). According to this configuration, the torch angle can be changed without moving the tip position of the welding wire.

[0177] (13) The conditions of the weaving reference trajectory include at least one of the stop time at each of the weaving ends, the weaving width in the groove width direction, the weaving width in the groove depth direction, and the speed ratio of the forward and backward paths in the weaving, (2) A weaving control method. According to this configuration, any weaving pattern can be set according to the welding conditions.

[0178] (14) A welding control device used for weaving control to weld a workpiece having a groove using a portable welding robot that moves on a guide rail, comprising: A setting step of setting at least a condition of a weaving reference locus related to a reference distance for determining a weaving pattern; a speed condition calculation step of calculating a speed condition to be instructed to a robot movement mechanism that moves the portable welding robot, for each of a plurality of predetermined directional components, based on the weaving pattern determined based on the setting step; having A function of synchronizing a stop signal command and a start signal command immediately after issuing the stop signal or after a predetermined stop time has elapsed for the speed conditions of each of the plurality of directional components calculated in the speed condition calculation step at least at the time of arrival of a weaving end. A welding control device characterized by: According to this configuration, good welding quality can be obtained in various welding positions, such as flat welding, horizontal welding, and vertical welding, using a portable welding robot that moves on a guide rail.

[0179] (15) A welding system comprising the welding control device described in (14). According to this configuration, good welding quality can be obtained in various welding positions, such as flat welding, horizontal welding, and vertical welding, using a portable welding robot that moves on a guide rail.

[0180] (16) A welding method using the welding system described in (15). According to this configuration, good welding quality can be obtained in various welding positions, such as flat welding, horizontal welding, and vertical welding, using a portable welding robot that moves on a guide rail.

[0181] (17) A weaving control program used for weaving control for welding a workpiece having a groove using a portable welding robot that moves on a guide rail, comprising: A setting step of setting at least a condition of a weaving reference locus related to a reference distance for determining a weaving pattern; a speed condition calculation step of calculating a speed condition to be instructed to a robot movement mechanism that moves the portable welding robot, for each of a plurality of predetermined directional components, based on the weaving pattern determined based on the setting step; having A function of synchronizing a stop signal command and a start signal command issued immediately after issuing the stop signal or after a predetermined stop time has elapsed, for the speed conditions of each of the plurality of directional components calculated in the speed condition calculation step, at least at the time of arrival of a weaving end. A weaving control program comprising: According to this configuration, good welding quality can be obtained in various welding positions, such as flat welding, horizontal welding, and vertical welding, using a portable welding robot that moves on a guide rail. [Explanation of symbols]

[0182] F n Groove shape detection position G Speed ​​ratio of outward and return trips P n Weld line position detection point VXP n Weld line position detection point P n Welding speed at YOP n Weld line position detection point P n Weaving width at Pt Pitch (reference distance) T1, T2 Stop time Tsu1 Acceleration time (rise period) Tsu2 Deceleration time (fall period) UL Weaving Pattern VH Set speed (2nd speed setting value) VL Initial speed (first speed setting value) VX Welding speed (X-axis direction speed) VY Weaving speed (Y-axis direction speed) VZ Weaving speed (Z-axis direction speed) WL welding line W o Work XO Shift Amount YO Weaving Width ZO Weaving Width θ3 Torch angle 10 Bevel 50 Welding System 100 Portable welding robot 120 Guide Rail 180 Approximate linear movement mechanism 181 X-axis movement mechanism (movement mechanism that moves the portable welding robot along the guide rail) 182 Y-axis movement mechanism (mechanism that moves in the groove width direction) 183 Z-axis movement mechanism (mechanism that moves in the groove depth direction) 600 Control device (welding control device)

Claims

1. A weaving control method for welding a workpiece having a groove using a portable welding robot that moves on a guide rail, comprising: A setting step of setting at least a condition of a weaving reference locus related to a reference distance for determining a weaving pattern; a speed condition calculation step of calculating a speed condition to be instructed to a robot movement mechanism that moves the portable welding robot, for each of a plurality of predetermined directional components, based on the weaving pattern determined based on the setting step; having a stop signal command and a start signal command issued immediately after issuing the stop signal or after a predetermined stop time has elapsed, for the speed conditions of each of the plurality of directional components calculated in the speed condition calculation step, are synchronized at least at the time of arrival of a weaving end, When the speed condition for each directional component includes a first speed setting value VL and a second speed setting value VH that is greater than the first speed setting value VL and varies for each weaving width, a speed condition process in which, in the speed condition from the start signal to the issuance of the stop signal, the first speed setting value VL is set after the start signal, the second speed setting value VH is set after the first speed setting value VL, the first speed setting value VL is set again after the second speed setting value VH, and the stop signal is set after the first speed setting value VL that has been set again; Repeated every time the start signal is issued. A weaving control method comprising:

2. The directional component is selected from at least two of the weld line direction of the workpiece, the groove width direction perpendicular to the weld line direction, and the groove depth direction perpendicular to each of the weld line direction and the groove width direction. The weaving control method according to claim 1 .

3. When a period from the first speed setting value VL to the second speed setting value VH is defined as a rise period, and a period from the second speed setting value VH to the first speed setting value VL is defined as a fall period, the absolute value of the slope of the speed condition in each of the rising period and the falling period is a fixed value; The weaving control method according to claim 1 or 2.

4. A weaving control method for welding a workpiece having a groove using a portable welding robot that moves on a guide rail, comprising: A setting step of setting at least a condition of a weaving reference locus related to a reference distance for determining a weaving pattern; a speed condition calculation step of calculating a speed condition to be instructed to a robot movement mechanism that moves the portable welding robot, for each of a plurality of predetermined directional components, based on the weaving pattern determined based on the setting step; having a stop signal command and a start signal command issued immediately after issuing the stop signal or after a predetermined stop time has elapsed, for the speed conditions of each of the plurality of directional components calculated in the speed condition calculation step, are synchronized at least at the time of arrival of a weaving end, The directional components are selected from at least two of a weld line direction of the workpiece, a groove width direction perpendicular to the weld line direction, and a groove depth direction perpendicular to each of the weld line direction and the groove width direction, The condition of the weaving reference locus includes, as the reference distance for determining the weaving pattern, a pitch Pt which is a distance between adjacent weaving ends on one side of a weld center line. A weaving control method comprising:

5. The weaving reference trajectory is determined so that the weaving end is located at Pt / 2, which is 1 / 2 of Pt. The weaving control method according to claim 4.

6. When the stop signal command and the start signal command are provided at a position other than the weaving end, The stop signal command and the start signal command are provided between the weaving end and Pt / 2. The weaving control method according to claim 5.

7. The condition of the weaving reference trajectory is: A shift amount set to shift the position of the weaving end on one side located at Pt / 2 has at least one directional component. The weaving control method according to claim 5 or 6.

8. The directional component for setting the shift amount is at least the weld line direction, Shifting the position of the weaving end in the welding progress direction in the weld line direction; The weaving control method according to claim 7.

9. A weaving control method for welding a workpiece having a groove using a portable welding robot that moves on a guide rail, comprising: A setting step of setting at least a condition of a weaving reference locus related to a reference distance for determining a weaving pattern; a speed condition calculation step of calculating a speed condition to be instructed to a robot movement mechanism that moves the portable welding robot, for each of a plurality of predetermined directional components, based on the weaving pattern determined based on the setting step; having a stop signal command and a start signal command issued immediately after issuing the stop signal or after a predetermined stop time has elapsed, for the speed conditions of each of the plurality of directional components calculated in the speed condition calculation step, are synchronized at least at the time of arrival of a weaving end, The directional components are selected from at least two of a weld line direction of the workpiece, a groove width direction perpendicular to the weld line direction, and a groove depth direction perpendicular to each of the weld line direction and the groove width direction, When changing the torch angle while the welding is stopped or during the welding, a mechanism for moving the portable welding robot in the weld line direction among the robot movement mechanism, the mechanism including an X-axis movement mechanism for moving the portable welding robot along the guide rail, and an approximate linear movement mechanism provided on the portable welding robot; a moving speed of the portable welding robot in the weld line direction is controlled by a combination of a moving speed based on the X-axis moving mechanism and a moving speed based on the approximate linear moving mechanism; A weaving control method comprising:

10. The robot movement mechanism includes an X-axis movement mechanism that moves the portable welding robot along the guide rail as a mechanism for moving the portable welding robot in the weld line direction, The robot moving mechanism includes a Y-axis moving mechanism and a Z-axis moving mechanism provided on the portable welding robot as mechanisms for moving the portable welding robot in the groove width direction and the groove depth direction, respectively. The weaving control method according to any one of claims 2 and 4 to 9.

11. The mechanism for moving the portable welding robot in the weld line direction further includes an approximate linear movement mechanism provided on the portable welding robot. The weaving control method according to claim 10.

12. The conditions of the weaving reference trajectory include at least one of the stop time at each of the weaving ends, the weaving width in the groove width direction, the weaving width in the groove depth direction, and the speed ratio of the forward and backward paths in the weaving. The weaving control method according to any one of claims 2, 4 and 9.

13. A welding control device used for weaving control for welding a workpiece having a groove using a portable welding robot that moves on a guide rail, A setting step of setting at least a condition of a weaving reference locus related to a reference distance for determining a weaving pattern; a speed condition calculation step of calculating a speed condition to be instructed to a robot movement mechanism that moves the portable welding robot, for each of a plurality of predetermined directional components, based on the weaving pattern determined based on the setting step; having a function of synchronizing a stop signal command and a start signal command issued immediately after issuing the stop signal or after a predetermined stop time has elapsed, for the speed conditions of each of the plurality of directional components calculated in the speed condition calculation step, at least at the time of arrival of a weaving end, When the speed condition for each directional component includes a first speed setting value VL and a second speed setting value VH that is greater than the first speed setting value VL and varies for each weaving width, a speed condition process in which, in the speed condition from the start signal to the issuance of the stop signal, the first speed setting value VL is set after the start signal, the second speed setting value VH is set after the first speed setting value VL, the first speed setting value VL is set again after the second speed setting value VH, and the stop signal is set after the first speed setting value VL that has been set again; Repeated every time the start signal is issued. A welding control device characterized by:

14. A welding control device used for weaving control for welding a workpiece having a groove using a portable welding robot that moves on a guide rail, A setting step of setting at least a condition of a weaving reference locus related to a reference distance for determining a weaving pattern; a speed condition calculation step of calculating a speed condition to be instructed to a robot movement mechanism that moves the portable welding robot, for each of a plurality of predetermined directional components, based on the weaving pattern determined based on the setting step; having a function of synchronizing a stop signal command and a start signal command issued immediately after issuing the stop signal or after a predetermined stop time has elapsed, for the speed conditions of each of the plurality of directional components calculated in the speed condition calculation step, at least at the time of arrival of a weaving end, The directional components are selected from at least two of a weld line direction of the workpiece, a groove width direction perpendicular to the weld line direction, and a groove depth direction perpendicular to each of the weld line direction and the groove width direction, The condition of the weaving reference locus includes, as the reference distance for determining the weaving pattern, a pitch Pt which is a distance between adjacent weaving ends on one side of a weld center line. A welding control device characterized by:

15. A welding control device used for weaving control for welding a workpiece having a groove using a portable welding robot that moves on a guide rail, A setting step of setting at least a condition of a weaving reference locus related to a reference distance for determining a weaving pattern; a speed condition calculation step of calculating a speed condition to be instructed to a robot movement mechanism that moves the portable welding robot, for each of a plurality of predetermined directional components, based on the weaving pattern determined based on the setting step; having a function of synchronizing a stop signal command and a start signal command issued immediately after issuing the stop signal or after a predetermined stop time has elapsed, for the speed conditions of each of the plurality of directional components calculated in the speed condition calculation step, at least at the time of arrival of a weaving end, The directional components are selected from at least two of a weld line direction of the workpiece, a groove width direction perpendicular to the weld line direction, and a groove depth direction perpendicular to each of the weld line direction and the groove width direction, When changing the torch angle while the welding is stopped or during the welding, a mechanism for moving the portable welding robot in the weld line direction among the robot movement mechanism, the mechanism including an X-axis movement mechanism for moving the portable welding robot along the guide rail, and an approximate linear movement mechanism provided on the portable welding robot; a moving speed of the portable welding robot in the weld line direction is controlled by a combination of a moving speed based on the X-axis moving mechanism and a moving speed based on the approximate linear moving mechanism; A welding control device characterized by:

16. A welding system comprising the welding control device according to any one of claims 13 to 15.

17. A welding method using the welding system of claim 16.

18. A weaving control program for use in weaving control for welding a workpiece having a groove using a portable welding robot that moves on a guide rail, comprising: A setting step of setting at least a condition of a weaving reference locus related to a reference distance for determining a weaving pattern; a speed condition calculation step of calculating a speed condition to be instructed to a robot movement mechanism that moves the portable welding robot, for each of a plurality of predetermined directional components, based on the weaving pattern determined based on the setting step; having a function of synchronizing a stop signal command and a start signal command issued immediately after issuing the stop signal or after a predetermined stop time has elapsed, for the speed conditions of each of the plurality of directional components calculated in the speed condition calculation step, at least at the time of arrival of a weaving end; When the speed condition for each directional component includes a first speed setting value VL and a second speed setting value VH that is greater than the first speed setting value VL and varies for each weaving width, a speed condition process in which, in the speed condition from the start signal to the issuance of the stop signal, the first speed setting value VL is set after the start signal, the second speed setting value VH is set after the first speed setting value VL, the first speed setting value VL is set again after the second speed setting value VH, and the stop signal is set after the first speed setting value VL that has been set again; Repeated every time the start signal is issued. A weaving control program comprising:

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