JP2004314108A - Automatic welding control method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an automatic welding control method capable of simultaneously and automatically welding a plurality of joints of the same work by using a plurality of welding robots, considerably reducing the welding time, and preventing deformation of a plate caused by welding distortion. <P>SOLUTION: A plurality of joints of the same work are automatically welded by using a plurality of welding robots. At least one of the sectional area of a groove and the weld length is different between the plurality of joints. Therefore, the feed speed of a welding wire is adjusted so that the welding time from a first base point to a second base point becomes equal for the plurality of welding robots if the volume to be welded is different when welding is performed from the first base point to the second base point. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to an automatic welding control method used, for example, when welding a column of a building steel frame, and more particularly to a control method in automatic welding for simultaneously welding a plurality of joints of the same work using a plurality of welding robots. .
[0002]
[Prior art]
Various methods have been proposed for automatically welding a rectangular member including a straight line portion and an arc portion (corner portion) as a welding line, such as a column core of a building steel frame, in which a welding line is placed in a vertical plane (Patent Documents) 1 to 4). In these methods, the work is fixed when welding the straight portion, and the work is rotated when welding the arc portion. Thereby, automatic welding is continuously performed without cutting the arc at the arc portion.
[0003]
In this case, welding conditions such as current, voltage and welding speed are changed between the straight portion and the arc portion in order to obtain a healthy weld continuously without breaking the arc at the arc portion (Patent Document 1 and Patent Document 2), welding conditions for a standard column core root gap prepared in advance are changed according to the actual root gap (Patent Documents 3 and 4).
[0004]
[Patent Document 1]
JP-A-2-307675
[Patent Document 2]
JP-A-2-307678
[Patent Document 3]
JP-A-6-285627
[Patent Document 4]
JP-A-6-285637
[0005]
[Problems to be solved by the invention]
However, in the above-described conventional technique, welding conditions such as welding speed are changed between a straight portion and an arc portion, and welding conditions are changed in accordance with a root gap. When the cross-sectional areas of the parts are different, different welding speeds are always applied. Therefore, a plurality of joints in the same work cannot be welded simultaneously.
[0006]
The present invention has been made in view of such a problem, it is possible to automatically weld a plurality of joints of the same workpiece simultaneously using a plurality of welding robots, it is possible to significantly reduce the welding time, Another object of the present invention is to provide an automatic welding control method capable of preventing deformation of a plate due to welding distortion.
[0007]
[Means for Solving the Problems]
The automatic welding control method according to the present invention is characterized in that in automatic welding in which a plurality of joints of the same work are simultaneously welded using a plurality of welding robots, at least one of a weld metal cross-sectional area and a welding length is between the plurality of joints. If the volume to be welded when welding from the base point to the next base point is different due to the difference, the welding wire from the base point to the next base point is the same for the plurality of welding robots. The feed speed is adjusted.
[0008]
When performing multi-layer welding by this automatic welding control method, set an appropriate welding current range that can be welded in each pass, set a welding current within the range, the welding time from the base point to the next base point, Even if the feed speed of the welding wire is adjusted to be the same for the plurality of welding robots, if the wall thickness in a specific pass is smaller than a desired value, the shortage of the wall thickness is compensated for in subsequent passes. , The total amount of meat at the end of all passes can be controlled to a desired range.
[0009]
Further, in the multi-layer welding, an appropriate welding current range that can be welded in each pass is set, a welding current is set within the range, and a welding time from the base point to the next base point is set for the plurality of welding robots. If it is determined that the total wall thickness at the end of all passes cannot be controlled to a desired range even if the feed speed of the welding wire is adjusted so as to be the same, one pass of at least one joint is determined. By welding individually, the total thickness at the end of all passes can be controlled to a desired range.
[0010]
Further, an appropriate welding current range that can be welded is set, a welding current is set within the range, and a welding wire is set so that the welding time from the base point to the next base point is the same for the plurality of welding robots. If it is determined that the thickness at the end of welding cannot be controlled to a desired range even after adjusting the feed speed of the welding wire, the thickness at the end of welding is adjusted by adjusting the protrusion length of the welding wire. It can be configured to control the amount to a desired range.
[0011]
The relationship between the current and the welding wire feed speed is correlated with a constant overhang length, and the current can be expressed as a function of the welding wire feed speed. Therefore, the same current can be generated at different wire feed speeds by changing the protrusion length. Therefore, in the above embodiment, the welding current does not deviate from the proper welding current range, and even if the welding wire feed speed is adjusted to the maximum, the wall thickness at the end of welding cannot be controlled to the desired range. By adjusting the protrusion length of the welding wire, the feed rate of the welding wire at the end of welding can be controlled within a desired range by changing the feed speed of the welding wire while maintaining the welding current.
[0012]
Furthermore, in the multi-pass welding, an appropriate welding current range that can be welded in each pass is set, and a welding current is set within the range. The welding time from the base point to the next base point is determined by the plurality of welding robots. If it is determined that the total wall thickness at the end of all passes cannot be controlled to a desired range even if the feed speed of the welding wire is controlled so that The passes can be individually welded and the total wall thickness at the end of all passes can be controlled to a desired range by adjusting the protrusion length of the welding wire.
[0013]
Thus, when one joint is viewed, even if the root gap of this specific joint is the same (constant), if the shape and welding conditions of other joints to be welded simultaneously change, this specific joint Use different welding conditions.
[0014]
In the present invention, a work having a different cross-sectional area (groove cross-sectional area) of a welding portion, such as a different root gap, a different plate thickness, or a different leg length, is rotated to weld a corner thereof. In the case of performing welding while performing welding, a plurality of welding robots (automatic welding devices) are applied at the same time, so that the welding time can be significantly reduced. Further, in the case where both sides of the same plate are welded, it is possible to suppress deformation of the plate due to welding strain, and it is possible to omit or reduce distortion correction work in a later process, and to add the plate to the plate in a later process. It is possible to suppress a displacement between the member and the member to be attached. As described above, the present invention is effective in reducing manufacturing costs and improving product quality.
[0015]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be specifically described with reference to the accompanying drawings.
FIG. 1 is a block diagram showing an apparatus used for an automatic welding control method according to an embodiment of the present invention, FIG. 2 is a view showing this automatic welding apparatus, and FIG. 3 is a perspective view showing a column to be assembled by welding. is there. This column is composed of a column core 3, a connection 2, and a column 1, as shown in FIG. As shown in FIG. 5, the column core 3 is assembled by joining diaphragms 5 to both ends of a cylindrical column portion 4 by welding. As shown in FIG. 6, the welding of the column part 4 and the diaphragm 5 is formed so that the end face of the column part 4 is inclined, the column part 4 is installed horizontally, and the diaphragm 5 is installed vertically. A groove is provided between the column portion 4 and the diaphragm 5, and a backing material 6 is disposed below the groove, and is automatically welded by a backing metal method, whereby the column portion 4 and the diaphragm are formed. 5 is joined.
[0016]
At this time, as shown in FIG. 7, a voltage is applied between the torch for supplying power to the welding wire and the material to be welded, and sensing that the welding wire is in contact with the material to be welded is detected by an electrical short circuit therebetween. The operation automatically detects the groove position. In the groove shown in FIG. 7, as an example, the welding wire is lowered obliquely so that the position of the tip of the welding wire moves from the point P1 to a position P2 immediately above the horizontal column portion 4, and then the sensing is performed. By operation, the wire is lowered vertically (-Z direction) and brought into contact with the column portion 4, and a distance TS1 between the positions P3 and P2 is obtained. Thereafter, the tip of the welding wire is raised obliquely to the position P4, and is moved horizontally (Y direction) from the position P4, and the distance TS2 from the position P5 at which the wire tip contacts the diaphragm 5 is determined. Thereafter, the tip of the welding wire is raised obliquely to the position P6, and further, the tip of the welding wire is lowered obliquely to the position P7, so that the groove position can be recognized.
[0017]
As shown in FIGS. 3 and 4, the column pillar is assembled by welding the connection 2 to the four side surfaces of the column part 4 of the core 3 and vertically welding the column 1 to the diaphragm 5 of the core 3. . The automatic welding apparatus shown in FIG. 2 shows a method for welding the column 1 to the diaphragm 5 of the core 3. In this automatic welding apparatus, two (one pair) positioners 31 and 32 and two welding robots 33 and 35 dispose a welding robot 33 between the positioners 31 and 32, and between the welding robots 33 and 34. The positioner 32 is arranged in tandem.
[0018]
The welding robots 33 and 34 have a movable carriage 35 running on a rail 50, on which a supply container 37 for a welding wire and a power supply device 42 are mounted, and are orthogonal to the rail 50 of the carriage 35. At one end in the direction, arms 40 and 41 are provided. A torch 38 is provided at the distal end of the arm 40, and the welding wire 39 wound and stored in a coil shape in the wire supply container 37 is unwound and passed through the conduit tube 36 to the torch 38. It is supplied to the welding portion through the torch 38. The welding power supply 42 is connected to the torch 38 by a cable 43, and supplies welding power to a welding wire 39 via the torch 38.
[0019]
The positioners 31 and 32 are provided such that a rotating unit 45 is rotatable with respect to a table 44. The rotating part 45 has a shape in which a central part is cut into a rectangular shape, and a fixing tool 46 for fixing an object to be welded is provided in at least one pair of opposing sides of the central notch. The workpiece is preliminarily welded and assembled as shown in FIG. 3, and the rotating part 45 fixes the column 1 by holding the surface of the column 1 as the workpiece by the fixture 46. The pair of positioners 31 and 32 are provided at positions where their cutouts are aligned (overlapping) when viewed in the longitudinal direction of the column 1. When the pair of columns 1 is clamped by the respective positioners 31 and 32, each column 1 The fixture 46 is adjusted so that the central axes of the two coincide.
[0020]
In this way, the pair of columns 1 of the work (column post) assembled by tacking is held at two positions by the positioners 31 and 32, respectively, to support the work, and the diaphragm of the end face of the column 1 and the column core 3 is provided. 5 are welded along the four sides of the end of the column 1. In this case, as shown in FIG. 8, the end (or cross section) of the column 1 is composed of four straight portions and four corners, and the corners are curved with an appropriate radius. are doing. Therefore, the welding line between the end of the column 1 and the surface of the diaphragm 5 is composed of four straight parts and four corners along the outer edge of the end of the column 1. Become.
[0021]
Then, as for the portion where the welding line is a straight line, the arms 40 and 41 of the welding robots 33 and 34 are moved while the positioners 31 and 32 are stationary, as shown in the period (1) in FIG. As shown at 1, the torch 38 is moved in the horizontal direction. Thereby, the straight portion of the welding line is welded by the welding wire 39. On the other hand, as shown in (2) to (5) of FIG. 9, the torch 38 is rotated while the column 1 and the diaphragm 5 are rotated (rotated) around the center axis of the column 1 by the positioners 31 and 32. Is moved in an arc shape through trajectories 2 to 10. As a result, the corner portion is welded by the welding wire 39, and the process proceeds to the welding of the next straight portion.
[0022]
At the time of welding by the welding robots 33 and 34, a welding line is detected by a touch sensing operation as described above. When there is no groove between the column 1 and the diaphragm 5, as shown in FIG. 10, a welding line is detected only by touch sensing without performing gap sensing. That is, the tip of the welding wire is located at a position above the column 1, and the tip of the wire is moved from P1 to P7. During this time, the surface of the column 1, that is, the position of the workpiece in the vertical direction is detected by the touch sensing operation from P2 to P3. Further, the surface of the diaphragm 5, that is, the position of the workpiece in the left-right direction is detected by the touch sensing operation from P4 to P5.
[0023]
On the other hand, when, for example, there is a groove of the same type as that of FIG. 6 between the column 1 and the diaphragm 5, as shown in FIG. 11, the welding line is detected by the gap sensing and the touch sensing operation. That is, the tip of the welding wire is located at a position above the column 1, and the tip of the wire is moved from P1 to P11. During this time, the surface of the column 1, that is, the position of the workpiece in the vertical direction is detected by the touch sensing operation from P2 to P3. Further, the surface of the diaphragm 5, that is, the position of the workpiece in the left-right direction is detected by the touch sensing operation from P4 to P5. Then, the position of the positioner is set to 0 °, 90 °, 180 °, and 270 °, and gap sensing is performed at the positions of P7 and P10 by moving from P6 to P11 at each positioner angle. Thereby, gaps on four sides are detected.
[0024]
As described above, the position and gap of the welding line at the welded portion are detected, and when the welded portion is straight, the welding robots 33 and 34 are fixed in a state where the column 1 which is the work is fixed at a position where the welding line is horizontal. The torch 38 is moved to weld the groove. On the other hand, when welding the corner portion of the work, the welding robots 33 and 34 weld the groove while rotating the work by the positioners 31 and 32.
[0025]
The welding method by the welding robot is controlled by the automatic control device shown in FIG. In FIG. 1, a main body 10 of two welding robots is controlled by a robot controller 14. A welding wire is fed to a welding torch 11 of the welding robot by a wire feeding device 12, and the welding wire is supplied from the torch 11 toward a welded portion of the work. This wire feeding is driven by the wire feeding device 12, and the wire feeding device 12 is controlled by a feed motor control device 13 a stored in the welding power supply device 13. In addition, power of the welding current value and the welding voltage value is supplied from the welding power supply device 13 to the welding torch 11, and power is supplied to the wire passing through the welding torch 11.
[0026]
A robot controller 14 controls the two robot bodies 10, a welding torch 11 provided at the tip of the neck of each robot body 10, and a welding power source 13 of an external device that supplies welding power to the work. One robot controller 14 is connected to a positioner 20 for controlling the posture of a workpiece to be welded. The two robot controllers 14 are connected by a communication cable for position control and interlock of each welding robot body 10.
[0027]
The robot controller 14 includes an input device 15, a storage device 18, a robot body controller 16, and an external controller 19, with an arithmetic processing device 17 at the center. The arithmetic processing device 17 stores the data in the storage device 18 based on the data input from the input device 15, and performs an arithmetic operation based on the data read from the storage device 18 to control the external control device 19 and the robot body control. It outputs a control signal to the device 16. The robot controller 14 outputs a control signal to the feed motor controller 13a to control the wire feed speed. One robot controller 14 controls a positioner main body 20 that adjusts the posture of the work.
[0028]
The robot body is, for example, a six-axis vertical articulated type, and a welding torch is provided at the tip of the wrist of the tip arm. The robot body performs an operation based on a teaching operation by a teaching operation input device, which is a teaching pendant, and performs a reproducing operation for reproducing a tip of a welding torch based on teaching program execution data created by the teaching operation.
[0029]
The positioner is, for example, a single-supported one-axis type that supports two positions of a work, which is a steel column, and has a work clamp portion for holding the work on the support driving member. Each welding of the work clamped to the work clamp portion is performed. The jointer is rotated by the positioner control device in response to a command from the robot control device, so that the joint has an appropriate welding posture.
[0030]
The welding power supply is, for example, of a carbon dioxide gas shield consumable electrode welding type, and is used as a welding power supply power supply unit for supplying welding power to the welding torch and the work and a sensing power supply unit. The welding power supply power supply unit receives welding start and end commands, welding current and voltage welding condition commands from the welding power control unit of the robot controller, and supplies welding power according to the welding condition commands to the welding torch and the workpiece. . The sensing power supply unit supplies a sensing voltage to the welding torch and the work in response to a sensing start and end command from the welding power supply control unit of the robot controller.
[0031]
The robot control device 14 includes an arithmetic processing device 17, a storage device 18, a robot main body control device 16 for controlling the position of each arm and the positioner of the robot main body, an external control device 19 such as a welding power source 13, and an input device 15 And so on.
[0032]
The arithmetic processing unit 17 performs a teaching calculation command operation of the robot body, a reproduction calculation command operation by the robot body and the welding power source, and the like. The storage device 18 has a teaching program storage unit and a primary storage unit. The teaching program storage unit stores a teaching program of each work by the teaching operation. The primary storage unit stores each detection information by the welding joint sensing operation. Is temporarily stored in each calculation unit. The robot main body control device 16 controls the movement of the robot main body in accordance with a teaching operation command from the robot operation operation unit. The external control device 19 includes a welding joint detection control unit and a welding power supply control unit. The welding joint detection control unit outputs welding joint position detection information by a sensing operation to a welding joint sensing calculation unit. The input welding start and end commands or welding current and voltage welding condition commands and the like are output from the robot operation calculation unit to the welding power supply power supply unit, and the input welding joint sensing start and end commands are output to the sensing power supply unit.
[0033]
Next, using the above-described apparatus, as shown in FIG. 2, two welding robots 33 and 34 simultaneously weld a welding portion between the flange portion 5 of the column core 3 and the column 1 at two locations. The control method in this case will be described.
[0034]
When welding column welding of architectural steel frames (backing groove type groove with different root gap) using two welding robots that use carbon dioxide gas as shielding gas, the part where the welding line is straight is Automatic welding is performed with the positioners 31 and 32 fixed, and automatic welding is performed while rotating the positioners 31 and 32 in a portion where the welding line is bent in an arc shape such as a corner portion. FIG. 9 is a diagram showing a locus of welding points when one welding robot welds a linear portion and an arc portion (corner portion) in column welding. If the column diameter, the corner radius, the column plate thickness, and the amount of eccentricity with respect to the center of rotation of the positioner are the same, this locus is the same for the welding robot 33 and the welding robot 34 even if the root gap is different. . As shown in this trajectory, during the period (1), the positioners 31, 32 are kept stationary, and the welding is performed by moving the arms 40, 41 of the welding robots 33, 34. On the other hand, during the period from (2) to (5), the arms 40 and 41 of the welding robots 33 and 34 are moved while the tip of the welding wire is "2" while rotating the column 1 by rotating the positioners 31 and 32. The corners are welded by moving them in an arc to 10 ".
[0035]
When operating a plurality of welding robots, the welding time between the base point and the next base point needs to be the same for each welding robot. In other words, in order to simultaneously weld a plurality of welded portions of the same workpiece at different connection positions with a plurality of welding robots, at least the arrival times at the start and end of the straight section and at the start and end of the corner section are the same. It is necessary to keep time. Actually, since the route gap fluctuates, it is necessary to change the conditions in a fine manner as shown in FIG. 9, and the steps are moved at the same time. Also, in the case of a straight section, when the fluctuation of the route gap is large between 1-2 and 10-1, it is necessary to change the conditions in detail.
[0036]
FIG. 12 is a schematic diagram showing the reference welding conditions and the conditions of the simultaneous welding joint. With reference to FIG. 12, a description will be given of a welding condition generation method. Prior to welding, the following processes (1) to (3) are performed.
{Circle around (1)} First, the relationship between the welding current and the appropriate arc voltage at that time with respect to the wire feed speed at a predetermined protrusion length is determined in advance.
(2) The relationship between the welding current and the appropriate arc voltage at that time with respect to the wire feed speed when the protrusion length is increased or decreased is obtained.
{Circle around (3)} At a predetermined protrusion length / reference root gap, welding conditions (reference welding conditions, that is, welding current, arc voltage, welding speed and target position) serving as a reference for each sheet thickness are obtained from experiments and the like. A variable welding current range and an arc voltage corresponding thereto are determined for the welding pass (each pass when performing multi-pass welding) (welding current range). At this time, it is considered that the lamination pattern of the thin plate, the welding current and the welding speed (the throat thickness of each pass is the same) are often the same as those in the middle of the thick plate. The conditions may be individual thicknesses, such as a pass.
[0037]
Next, the following processes (4) to (9) are performed when welding is performed.
{Circle around (4)} For the paths to be welded at the same time, when the throat thickness is the same under the reference welding conditions after the completion of this pass, that is, when the lamination pattern, welding current and welding speed are the same, each reference welding condition and the root of the joint From the gap and the previously welded throat thickness, if there is a previously welded pass, the amount of weld metal required for welding between the base points assuming that the throat thickness under the standard welding conditions is maintained is calculated. The average value is set as the target amount of deposited metal (target deposited metal amount). From the relationship between the wire feed speed and the welding current obtained in advance, the welding time that is the target amount of deposited metal when the current value of the reference welding condition of this pass is used is obtained. For the straight portion, the welding speed is calculated from the welding length between the base points. For the corners, the welding time is the rotation time of the positioner, so the welding length according to the welding position to be welded this time is determined in consideration of the difference in the throat thickness up to that point, and the welding speed (work and workpiece) is determined. Calculate the relative speed with the torch). From the determined welding speed and the amount of weld metal required in this joint for each joint, the required wire feed speed for each joint is determined.From the relationship between the wire feed speed and welding current determined in advance, the actual current value and Determine the corresponding arc voltage.
[0038]
When the target throat thickness after this pass is different, that is, when the lamination pattern, welding current and welding speed are different, each reference welding condition and the root gap of the joint, and if there is a previously welded pass, then From the welded throat thickness, determine the amount of weld metal required for welding between the base points assuming that the throat thickness under the standard welding conditions is maintained for each joint, and determine the average value of the amount of weld metal to be welded, that is, Set the target amount of deposited metal. Next, the wire feed speed for the current value of the path to be welded at the same time is calculated from the respective standard welding conditions, and the average value is calculated, and this is set as the average wire feed speed. The welding time at this time is determined from the target weld metal amount and the average wire feed speed. For the straight portion, the welding speed is calculated from the welding length between the base points and the welding time. For the corners, the welding time is the rotation time of the positioner, so the welding length according to the welding position to be welded this time is determined in consideration of the difference in the throat thickness up to that point, and the welding speed (work and workpiece) is determined. The relative speed of the torch) is calculated. From the determined welding speed and the amount of weld metal required in this joint for each joint, the required wire feed speed is determined for each joint, and the actual current value and its correspondence are determined from the relationship between the wire feed speed and the welding current determined in advance. The arc voltage to be applied.
(5) At this time, if the actual current value is out of the welding current range and the torch and the robot arm do not interfere with the work, the processing of (9) described below is performed. If the actual current value is outside the welding current range even after this processing, the current value is adjusted to the upper and lower limits, and the wire feed amount and the arc voltage are changed accordingly.
(6) When the welding current is changed within the predetermined welding current range and the wall thickness is changed and the welding is performed, the amount of deposited metal in each pass of each joint does not become a desired value. In this case, the insufficient welding is performed. Carry the amount of metal or overflowed deposited metal to the next pass. Even when the throat thickness of the current pass becomes 0 or less, welding is performed at the lower limit value, and the overflowing amount of deposited metal is carried over to the next pass.
{Circle around (7)} The same processing as described above is performed by adding the amount of carried-over deposited metal to the amount of deposited metal required in the next pass of the joint.
(8) Even if this is repeated, if the difference in the amount of weld metal between the joints becomes large, the welding result of each joint at the end of all the passes will have an error in the amount of weld metal, and thus will be outside the acceptable range of the desired welding quality. In this case, one or more paths are not simultaneously welded, that is, at least one of a plurality of joints is not simultaneously welded, and the welding current under the reference welding condition is assumed again. Then, the positioner rotation speed (welding speed) at this time is recalculated in accordance with the remaining amount of deposited metal required up to this pass, and welding is performed. At this time, the welding of this pass shall be performed before or after welding of the remaining joints. The lamination schedule determined by this method for simultaneous welding or non-simultaneous welding is called a pass schedule, and this pass schedule is determined before the start of welding.
(9) Since the welding current range is limited, if the difference in the amount of weld metal between the joints increases, the number of paths that cannot be simultaneously welded increases. In this case, the operation time approaches the case of individually welding, and the effect of simultaneous welding is weakened. If the amount of deposited metal cannot be set to a desired value even when the current value is set to the upper and lower limits, the welding amount is set to a desired value while maintaining the welding current within the range by changing the wire protrusion length. That is, a change in the correlation between the welding current and the arc voltage with respect to the change in the protrusion length is determined in advance by experiments or the like, and the welding current value at the wire feed amount determined from the welding speed and the amount of the deposited metal is within the current range. By changing the protruding length, proper welding conditions are maintained and simultaneous welding is enabled.
[0039]
The amount of heat input (J / cm) to the workpiece during welding is obtained as current (A) × voltage (V) × 60 / welding speed (cm / min). In general, the heat input is higher when the amount of the deposited metal in one pass is larger than when the amount is small. In addition, increasing the heat input increases the amount of deposited metal per unit time, so that the welding time can be shortened and work efficiency can be increased. Therefore, for the above item (4), the welding speed (welding time) at which the maximum heat input is obtained is determined by using the maximum value of the welding current that can use the welding conditions of the joint with the largest amount of deposited metal. There is also a method of calculating welding conditions of a simultaneous welding joint based on the welding speed (welding time). The method described in the above item (4) is a calculation method based on the idea that a condition as close as possible to the welding condition is selected under the premise that the reference welding condition is totally optimum.
[0040]
The welding conditions are generated by the above-described welding condition generating method, and automatic welding is performed by the welding robot based on the generated welding conditions. First, work shape data is input from the input device 15. As shown in FIG. 8, this work shape data includes, for example, column thickness (root gap when gap sensing is not performed), column longitudinal diameter, column lateral diameter, and corner radius (from the first corner portion to the (Up to four corners) and the length in the longitudinal direction, and these are input for each joint. Then, sensing data is generated by the method shown in FIG. 10 or FIG. Welding lengths of at least four straight lines (from the beginning to the end of the straight line x 4 surfaces) and four corners (from the start to the end of corners x 4 corners) of each joint obtained from the input work shape data and sensing results From the basic welding conditions of the root gap and the thickness of the root gap, the welding conditions shown in the above (4) to (7) and (9) are generated. In this case, if the change in the gap and the wall thickness is large, the section to be divided is made fine.
[0041]
If the generated welding conditions are out of the desired throat thickness range, the above process (8) is performed until the generated throat thickness falls within the desired throat thickness range, and welding conditions (pass schedule) including application or non-application of simultaneous welding are performed. ). Then, welding from the first pass is executed based on the completed welding conditions.
[0042]
【The invention's effect】
As described above in detail, according to the present invention, when welding a welding line having a straight line portion and an arc portion while rotating a workpiece with respect to the arc portion, the same welding is performed using a plurality of welding robots. It is possible to simultaneously weld a plurality of welded portions of a work, and this has an excellent effect that the welding time can be greatly reduced. In the case where both sides of the same plate are to be welded, welding can be performed simultaneously by two welding robots, whereby deformation of the plate due to welding strain can be suppressed.
[Brief description of the drawings]
FIG. 1 is a block diagram showing an apparatus used in an automatic welding control method according to an embodiment of the present invention.
FIG. 2 is a view showing an automatic welding device.
FIG. 3 is a perspective view showing a column to be assembled by welding.
FIG. 4 is an assembly view of a column.
FIG. 5 is a view showing a structure of a column core 3;
FIG. 6 is a diagram showing a method of assembling the column core 3 by welding.
FIG. 7 is a diagram showing a sensing operation.
FIG. 8 is a diagram showing a cross section of a column and showing input data to an automatic control device.
FIG. 9 is a diagram showing a trajectory of a tip of a welding wire in a straight portion and an arc portion.
FIG. 10 is a diagram illustrating a touch sensing operation when gap sensing is not performed.
FIG. 11 is a diagram illustrating a touch sensing operation when gap sensing is performed.
FIG. 12 is a schematic view showing a standard welding condition and a condition of a simultaneous welding joint.
[Explanation of symbols]
1: Column
2: Connection
3: Column core
4: Column part
5: Diaphragm
6: Backing material
10: Welding robot body
11: welding torch
12: Wire feeder
13: welding power supply
13a: feed motor control device
14: Robot controller
20: Positioner body
31, 32: Positioner
33, 34: welding robot
35: Dolly
36: Rail
37: Welding wire storage container
38: Torch
39: welding wire
40, 41: Arm
42: Power supply
43: Cable
45: Rotating part
50: Rail

Claims (5)

In automatic welding in which a plurality of joints of the same work are simultaneously welded using a plurality of welding robots, since at least one of a welded metal cross-sectional area and a welding length is different between the plurality of joints, from a base point to a next base point. When the volumes to be welded at the time of welding are different, the feed speed of the welding wire is adjusted so that the welding time from the base point to the next base point is the same for the plurality of welding robots. Automatic welding control method. In multi-pass welding, a proper welding current range that can be welded in each pass is set, and a welding current is set within the range.The welding time from the base point to the next base point is the same for the plurality of welding robots. Therefore, even if the feed rate of the welding wire is adjusted, if the wall thickness in a specific pass is smaller than a desired value, the shortage of the wall thickness is compensated for in subsequent passes, and the total wall thickness at the end of all passes is obtained. 2. The automatic welding control method according to claim 1, wherein the amount is controlled within a desired range. In multi-pass welding, a proper welding current range that can be welded in each pass is set, and a welding current is set within the range.The welding time from the base point to the next base point is the same for the plurality of welding robots. Thus, if it is determined that the total wall thickness at the end of all passes cannot be controlled to a desired range even if the feed speed of the welding wire is adjusted, at least one pass of one joint is determined. 2. The automatic welding control method according to claim 1, wherein the total wall thickness at the end of all the passes is controlled to a desired range by individually welding. Set a proper welding current range that can be welded, set a welding current within the range, and feed the welding wire so that the welding time from the base point to the next base point is the same for the plurality of welding robots. If it is determined that the thickness at the end of welding cannot be controlled to a desired range even when the speed is adjusted, the thickness at the end of welding is adjusted by adjusting the length of protrusion of the welding wire. 2. The automatic welding control method according to claim 1, wherein the control is performed within a desired range. In multi-pass welding, a proper welding current range that can be welded in each pass is set, and a welding current is set within the range.The welding time from the base point to the next base point is the same for the plurality of welding robots. Thus, if it is determined that the total wall thickness at the end of all passes cannot be controlled to the desired range even if the feed speed of the welding wire is adjusted, at least one pass of one joint is determined. 2. The automatic welding control method according to claim 1, wherein the total wall thickness at the end of all the passes is controlled within a desired range by individually welding and adjusting a protrusion length of the welding wire. .

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