JP4864233B2 - Consumable two-electrode arc welding end method, welding end control method, and welding robot - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to improvement of a method for terminating arc welding in which two consumable electrodes (hereinafter referred to as wires) are fed and welded in one torch in consumable electrode arc welding.
[0002]
[Prior art]
In the construction of various welded structures, thin plate high-speed welding or thick plate high-weld welding is performed to improve work efficiency. To further improve the efficiency, as shown in FIG. A consumable electrode arc welding method of a two-electrode, one-torch system that feeds a wire is employed. In the figure, the leading wire tip 3a is supplied from a welding power source (not shown) between the leading tip 1 and the trailing tip 2 and the workpiece 8 and fed from the leading tip 1 and the trailing tip 2, respectively. And arcs 5 and 6 are generated from the trailing wire tip 4a, respectively. The nozzle 10 surrounds the leading tip 1 and the trailing tip 2 and supplies a shielding gas 11 to the inside of the nozzle 10.
[0003]
In FIG. 2, the molten metal in the molten pool 7 formed by the arc 5 generated from the preceding wire 3 tries to flow backward due to surface tension, but the arc force generated from the trailing wire 4 is The molten metal that is going to flow backward is pushed back directly under the arc 5 generated from the preceding wire 3 to make the amount of molten metal uniform at each welding position.
[0004]
FIG. 3 is a diagram showing a general configuration of the above-described two-electrode one-torch type welding robot. In the figure, a welding torch 14 having a leading tip 1 and a trailing tip 2 is attached to the tip of a manipulator 21, and a leading wire welding power supply device 23 to be supplied to the leading tip 1 and a trailing wire to be supplied to the trailing tip 2. The welding power supply device 24 supplies welding power between the leading tip 1 and the trailing tip 2 and the workpiece 8. The leading wire feeding device 25 and the trailing wire feeding device 26 feed the wires to the leading chip 1 and the trailing chip 2, respectively. The robot control device 27 controls the manipulator 21, the preceding wire welding power source device 23, and the subsequent wire welding power source device 24.
When the welding direction is changed, the leading and trailing are interchanged. Therefore, the leading tip 1, the leading wire 3, the leading wire feeding device 25, the leading wire welding power supply device 23, the trailing tip 2, the trailing wire 4, and the trailing The preceding and following descriptions of the respective reference numerals of the row wire feeding device 26 and the subsequent wire welding power source device 24 are interchanged.
[0005]
[Prior art 1]
A welding end method (hereinafter, referred to as “prior art 1”) using a conventionally proposed two-electrode, one-torch welding robot will be described with reference to FIGS. 4 and 5. In order to simplify the explanation, it is assumed that the leading wire 3 and the trailing wire 4 are fed. FIG. 4 is a diagram for explaining a method for ending the two-electrode one-torch type consumable electrode arc welding according to Prior Art 1, and FIG. It is a figure explaining the termination method.
[0006]
FIG. 4 (A) shows a state during consumable electrode arc welding of the two-electrode one-torch method. In the figure, the leading wire 3 and the trailing wire 4 protrude from the nozzle 10, and the leading wire 3 and the trailing wire 4 and the covering wire 4 are connected to the leading wire welding power source 23 and the trailing wire welding power source 24 shown in FIG. Electric power is supplied between the welding object 8 and arcs 5 and 6 are generated from the leading wire tip 3a and the trailing wire tip 4a, respectively, and a weld bead 9 is formed.
[0007]
Then, as shown in FIG. 4B, when the leading wire tip 3a reaches the welding end position P2, which is the terminal portion of the weld bead formed by the leading wire 3, the robot controller 27 shown in FIG. It is determined that the leading wire tip 3a has reached the welding end position P2, and a crater processing command signal is output to the leading wire welding power source device 23 and the trailing wire welding power source device 24.
[0008]
Here, the crater process will be described. At the weld bead end portion, a so-called crater is formed in the molten pool immediately under the arc, which is depressed by the arc force. This crater is likely to have defects such as cracks and shrinkage holes. In order to prevent this, the operation of reducing or eliminating the crater is called crater processing. In general, a method of decreasing the welding current continuously or stepwise at the end portion of the weld bead, or interrupting the welding current is used.
In addition, the crater process of the above-described prior art 1 is referred to as a second crater process in the present invention.
[0009]
After that, when the crater process is finished, the robot control device 27 shown in FIG. 3 inputs a welding end command signal to the preceding wire welding power source device 23 and the subsequent wire welding power source device 24, and FIG. ) Finish the welding as shown in FIG.
[0010]
FIG. 5 is a diagram showing an appearance of a weld bead end portion according to a consumable electrode arc welding end method of the two-electrode one-torch method of the prior art 1. As shown in the figure, since both the preceding wire 3 and the succeeding wire 4 perform crater processing, two crater processing traces 15 and 16 are generated. Therefore, not only the appearance of the weld bead is deteriorated, but also when the crater process is performed, a recess 15a is generated between the two crater process traces, and the weld joint strength is weakened. In addition, when performing high-speed welding, the depressed molten pool before the crater treatment is solidified without being cratered and becomes a molten pool trace 13, so that defects such as cracks and shrinkage holes are likely to occur.
[0011]
[Prior Art 2]
In order to solve the above-mentioned problems, Japanese Patent Application Laid-Open No. 2001-113373 “Control Method of Tandem Arc Welding” (hereinafter referred to as Prior Art 2) has been proposed.
FIG. 6 is a diagram illustrating an apparatus for performing tandem arc welding according to Conventional Technique 2. In the figure, a leading wire welding power source device 44 and a trailing wire welding power source device 45 supply power between the leading tip 41 and the trailing tip 42 and the workpiece 2 respectively. The leading wire feeding device 46 and the trailing wire feeding device 47 supply the leading wire 48 and the trailing wire 49 to the leading tip 41 and the trailing tip 42, respectively, and generate an arc 50 and an arc 51. A molten pool 52 is formed by the arc 50 and the arc 51, and a weld bead 53 is formed behind the molten pool 52. The welding control device 54 performs operation control of the welding robot 55 and output control of the power supply device 44 for leading wire welding and the power supply device 45 for subsequent wire welding.
[0012]
FIG. 7 is a time chart for explaining a control method at the end of welding according to the prior art 2. FIG. 7 (A) shows the elapsed time t of the preceding wire energization current, and FIG. 7 (B) shows the preceding wire applied voltage. (C) shows the time t of the moving speed of the leading tip 41 and the trailing tip 42, and (D) shows the time t of the trailing wire energization current. FIG. 4E shows the passage of time t of the trailing wire applied voltage.
[0013]
When the leading tip 41 reaches the welding end position P2 at time t1 shown in FIG. 7, the energizing current of the leading wire 48 is decreased from I1 to I2 as shown in FIG. As shown in B), the applied voltage of the leading wire 48 is decreased from E1 to E2.
Thereafter, after the waiting time Td1 has elapsed, the arc of the preceding wire 48 is stopped and the molten pool is reduced.
[0014]
When the succeeding tip 42 reaches the welding end position P2 at time t2 in the figure, the movement of the leading tip 41 and the succeeding tip 42 is stopped as shown in FIG. Then, as shown in FIG. 4D, the energization current of the trailing wire 49 is decreased from I3 to I4, and as shown in FIG. 4E, the applied voltage of the trailing wire 49 is changed from E3 to E4. Reduce to.
Thereafter, the arc of the trailing wire 49 is stopped after the waiting time Td2 has elapsed.
[0015]
The energizing currents I2 and I4 reduced before the arc is stopped are appropriately about half of the normal welding currents I1 and I2, respectively. Further, the applied voltages E2 and E4 reduced before stopping the arc may be set to values suitable for the reduced energization currents I2 and I4, respectively.
[0016]
Thus, by reducing the current applied to the preceding wire 48 and the succeeding wire 49 and the voltage to be applied at the end of welding and stopping after the waiting time, it is possible not only to prevent the molten metal from scattering and to stabilize the molten pool. Although it has been disclosed that it is possible to obtain a good weld end portion having no welding defects such as unevenness, pits and cracks, it has the following problems.
[0017]
[Problems to be solved by the invention]
In the prior art 2 described above, as shown in FIG. 7, after reducing the current and voltage applied to the leading wire 48, welding is performed only by the trailing wire 49. The welding speed at this time is a speed at which high-speed welding is performed, as shown in FIG. Therefore, after reducing the current and voltage applied to the leading wire 48, the moving speed of the leading tip 41 and the trailing tip 42 is too fast to perform welding only with the arc of the trailing wire 49, so that the weld bead width In some cases, the weld bead near the welding end position cannot be obtained with a beautiful appearance.
Further, in high-speed welding in which the welding speed exceeds 2 [m / min], in order to obtain a uniform weld bead, the ratio of the current applied to the preceding wire 48 and the current applied to the subsequent wire 49 is 2: 1. Degree. Accordingly, if the current applied to the preceding wire 48 is reduced and stopped while maintaining the high-speed welding speed, the current ratio applied to the preceding wire 48 and the succeeding wire 49 is not an appropriate ratio, and high-speed welding is performed. In this case, the arc force of the trailing wire 49 becomes excessive, the arc force blows off the molten pool, the weld bead becomes non-uniform, and a welding defect occurs.
[0018]
Furthermore, in the prior art 2, for example, as shown in FIG. 8, when performing fillet welding of a bottom plate having a box shape and a wall on the front surface in the welding direction at the welding end position P2, as shown in FIG. Since the leading tip 41 reaches the welding end position P2, the leading tip 41 hits the wall, and the leading tip 41 and the trailing tip 42 cannot be moved in the welding direction, the control method for tandem arc welding according to the related art 2 is executed. Can not do it. FIG. 8 is a diagram for explaining a case where the shape of the workpiece 8 is box-shaped and fillet welding of the bottom plate is performed. Accordingly, since the trailing tip 42 cannot reach the welding end position P2, as shown in FIG. 9, the welding in the vicinity of the welding end position P2 becomes welding by only the preceding wire 48, so that the vicinity of the welding end position P2 The weld bead 9a becomes thinner, or the weld bead 9 becomes non-uniform, resulting in a weld defect. FIG. 9 is a diagram for explaining that the weld bead 9 is not uniform at the welding end position P2 when the shape of the workpiece 8 is box-shaped and the fillet welding of the bottom plate is performed according to the related art 2. .
[0019]
[Means for Solving the Problems]
The invention described in claim 1 at the time of filing is the invention of Example 1 shown in FIGS.
In a consumable two-electrode arc welding end method in which two wires are fed and welded in one torch, feeding and energization of the trailing wire 4 are stopped at the welding end position P2, and the welding torch is reversed in the welding direction. The leading wire 3 performs the first crater processing while moving the first crater processing distance D1 in the direction at a speed slower than the normal welding speed, and then stops the movement of the welding torch and the leading wire 3 performs the second crater processing. This is a consumable two-electrode arc welding end method.
[0020]
The invention according to claim 2 at the time of filing is a consumable two-electrode arc welding end method in which the first crater processing distance D1 according to claim 1 at the time of filing is “the distance between the wire tips of the standard protruding length” L2. is there.
[0021]
The invention according to claim 3 at the time of filing is the end of consumable two-electrode arc welding in which the first crater processing distance D1 according to claim 1 at the time of filing is calculated from the first crater processing moving speed and the first crater processing moving time. Is the method.
[0022]
The invention described in claim 4 at the time of filing is the welding end method of Example 2 shown in FIG.
In a consumable two-electrode arc welding end method in which two wires are fed and welded in one torch,
When the leading tip 1 reaches the welding end position P2, the feeding and energization of the trailing wire 4 are stopped, and the first speed at a speed lower than the normal welding speed is moved while moving the welding torch in the direction opposite to the welding direction. The preceding wire 3 performs the first crater processing at the first crater processing current value and the first crater processing voltage value at the crater processing speed,
Next, when the preceding wire 3 reaches the second crater processing position P3, the welding torch is stopped, and the second crater processing is started and preset by the second crater processing current value and the second crater processing voltage value. This is a consumable two-electrode arc welding end method in which the measurement of the second crater processing time is started and the second crater processing is ended when the measurement of the second crater processing time is completed.
[0031]
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 is a diagram that best represents the features of the invention according to the present application. Since it is the same as FIG. 10 described later, the description will be described later with reference to FIG.
An embodiment of the invention is a welding robot according to claim 12 at the time of filing, wherein the welding robot feeds and welds two wires in one torch, and each welding section of the work piece 8 is welded. A work program file output circuit 29 that stores predetermined {circle around (1)} welding start parameters and {circle around (2)} welding end parameters, a predetermined “standard protruding length of the preceding wire 3 or the succeeding wire 4” L1, and The electrode parameter output circuit 31 storing the electrode parameter consisting of the “standard protrusion length wire tip distance” L2 and the output signal of the work program file output circuit 29 are input, and welding is started from the welding start position. Each joint angle of the manipulator 21 for moving the welding torch to the end position is calculated (to a servo control circuit 33 described later) and the calculated value of each joint angle is calculated. (2) When the welding torch reaches the welding start position, a preceding wire welding start command signal S1 is output (to a preceding wire welding condition output circuit 35 described later), and a subsequent wire welding start command signal S2 is output. (To a subsequent wire welding condition output circuit 36 to be described later), to output a normal welding speed (to a servo control circuit 33 to be described later), and (3) when the leading tip 1 reaches the welding end position P2, A subsequent wire welding end processing command signal S10 is output (to a subsequent wire welding condition output circuit 36 described later), and a first crater processing command signal S11 is output (to a preceding wire welding condition output circuit 35 described later). The first crater processing speed that is slower than the welding speed is output (to a servo control circuit 33 to be described later). (4) When the preceding chip 1 reaches the second crater processing position P3, the second clay Each of a welding torch movement path calculation circuit 32 that outputs a processing command signal S13 (to a later-described preceding wire welding condition output circuit 36) and (1) each of the manipulator 21 for moving the welding torch from the welding torch movement path calculation circuit 32 When the calculated value of the joint angle is input and the manipulator 21 is controlled, (2) when the first crater processing speed is input, the welding torch is moved in the direction opposite to the welding direction, and (3) the leading tip 1 is the second A servo control circuit 33 that stops the manipulator 21 when the crater processing position P3 is reached, and (1) a signal that commands energization of the welding current of the preceding wire 3 when the preceding wire welding start command signal S1 is input. Is output (to the power supply device for preceding wire welding described later), and (2) when the arc 5 is generated at the leading wire tip 3a, the leading wire welding is started. When the completion signal S3 is output to the welding torch movement path calculation circuit 32, and (3) when the first crater processing command signal S11 is input, the first crater processing current value and the first crater processing voltage value are set (preceding described later). (4) When the second crater processing command signal S13 is input, the second crater processing current value and the second crater processing voltage value are output (to a later-described preceding wire welding power source device). 23), the measurement of the second crater processing time set in advance is started, and when the measurement of the second crater processing time is completed, the command to perform the anti-stick processing and the welding release processing of the preceding wire 3 is completed. When a signal is output (to a power supply device for preceding wire welding 23 described later) and it is determined that the preceding wire 3 is not welded, the preceding wire welding end processing completion signal S14 is transmitted to the welding torch moving time. When the preceding wire welding condition output circuit 35 output to the calculation circuit 32 and a signal for commanding the energization of the welding current of the preceding wire 3 from the preceding wire welding condition output circuit 35 are input, the welding current is applied to the preceding wire 3 A preceding wire welding power source device 23 that performs anti-stick processing and welding release processing of the preceding wire 3 when a command signal for performing anti-stick processing and welding release processing of the preceding wire 3 is input; When the wire welding start command signal S2 is input, a signal for commanding the energization of the welding current of the succeeding wire 4 is output (to the power supply device 24 for the succeeding wire welding described later), and (2) the tip of the succeeding wire When the arc 6 is generated in 4a, the succeeding wire welding start completion signal S4 is output to the welding torch movement path calculation circuit 32, and (3) the succeeding wire welding end processing command signal S1. Is input, a command signal for performing anti-stick processing and welding release processing of the succeeding wire 4 is output (to the power device 24 for succeeding wire welding described later), and it is determined that the succeeding wire 4 is not welded. In some cases, the succeeding wire welding condition output circuit 36 outputs a succeeding wire welding end processing completion signal S12 to the welding torch movement path calculation circuit 32, and the welding current of the succeeding wire 4 from the succeeding wire welding condition output circuit 36. When a signal for commanding energization is input, a welding current is applied to the succeeding wire 4, and when a command signal for performing anti-stick processing and welding release processing for the succeeding wire 4 is input, It is a welding robot provided with the power supply apparatus 24 for the subsequent wire welding which performs an anti-stick process and a welding release process.
[0032]
【Example】
Hereinafter, the welding end method will be described in the first embodiment, and then the welding end control method and the welding robot by the robot controller 27 in the second embodiment will be described.
[0033]
[Example 1]
FIG. 10 is a diagram for explaining an embodiment of the consumable two-electrode arc welding end method of the present invention. FIG. 4A shows a state during consumable electrode arc welding of the two-electrode one-torch method, and the same functions as shown in FIG.
[0034]
As shown in FIG. 10B, when the leading wire tip 3a reaches the welding end position P2, the robot controller 27 shown in FIG. 3 indicates that the leading wire tip 3a has reached the welding end position P2. , The welding end command signal is output to the subsequent wire welding power source device 24, and the first crater processing command signal is output to the preceding wire welding power source device 23. L2 shown in FIG. 10 (B) is the distance between the wire tips of the standard protruding length, and can be used as the following wire first crater processing distance D1.
Thereafter, as shown in FIG. 3C, the preceding wire 3 performs the first crater process while the welding torch moves the first crater processing distance D1, for example, the distance L2 between the wire tips, in the direction opposite to the welding direction. .
[0035]
Here, the first crater process is to stop the feeding and energization of the succeeding wire 4, perform the welding end process while energizing only the preceding wire 3 and moving the welding torch in the direction opposite to the welding direction. is there. The welding current value, welding voltage value, and welding speed during the first crater treatment period can be arbitrarily set. Usually, the welding current value and welding voltage for welding (hereinafter referred to as normal welding) until the welding torch reaches the welding end position. The value is lower than the welding speed.
[0036]
FIG. 11 is a diagram illustrating a welding end method subsequent to FIG. 10 in the welding end method of the first embodiment. 11A to 11C that follow FIG. 10C will be described. When the welding torch finishes moving the first crater processing distance D1, for example, the wire tip distance L2, in the direction opposite to the welding direction, the welding torch stops, and the robot controller 27 shown in FIG. A second crater processing command signal is output to the welding power supply device 23, and the leading wire 3 performs the second crater processing as shown in FIG.
[0037]
Here, the second crater process is to process the crater with the welding torch stopped after the preceding wire 3 performs the first crater process, and arbitrarily sets the welding current value and the welding voltage value. it can. This corresponds to the crater processing described in Related Art 1.
[0038]
When the preceding wire 3 finishes the second crater process, the robot control device 27 shown in FIG. 3 outputs a welding end command signal to the preceding wire welding power supply device 23, as shown in FIG. 11 (B). Finish welding.
[0039]
As described above, in the first embodiment, only the preceding wire 3 performs the crater processing described in the related art 1 in the second crater processing, so that only one crater processing trace 15 is generated as shown in FIG. Absent. In addition, since the moving speed of the welding torch during the first crater process shown in FIG. 10C is decelerated from the normal welding speed, the molten metal generated by the leading wire 3 while the welding torch is moved is an arc. The molten metal is pushed in the moving direction of the torch by force, and the molten metal can fill the molten pool recessed by the arc force of the trailing wire 4, and the weld pool mark 13 shown in FIG. The appearance is good.
[0040]
Furthermore, even when the fillet welding is performed on the bottom plate having the box-shaped shape of the workpiece 8 shown in FIG. 8 and having a wall in front of the welding end position P2 in the welding direction, the preceding wire 3 is placed at the welding end position P2. Then, after the energization of the trailing wire 4 is stopped, the leading wire 3 and the trailing wire 4 are moved in the direction opposite to the welding direction so that the leading wire 3 performs the first crater process. After the wire 4 has moved the first crater processing distance D1, the preceding wire 3 performs the second crater processing, so that a uniform weld bead 9 can be obtained as shown in FIG. FIG. 12 is a diagram for explaining a case where the shape of the workpiece 8 is box-shaped and fillet welding of the bottom plate is performed by the welding end method of the first embodiment.
[0041]
In the first embodiment, the first crater processing distance D1 can be set to “a distance between the wire tips of the standard protruding length” L2. Further, the first crater processing distance D1 can be calculated from the first crater processing moving speed and the first crater processing moving time. Further, the first crater processing distance D1 can be calculated as a percentage of the “standard protrusion length distance between the wire tips” L2.
[0042]
[Explanation of FIG. 13]
FIG. 13 is a view for explaining the moving distance of the welding torch from the welding start position P1 to the first crater processing start position and the second crater processing position when the preceding wire 3 of the first embodiment of the present invention performs crater processing. FIG.
In this figure, the distance from “welding start position” P1 which is the start end of the weld bead formed by the succeeding wire 4 at the start of welding to “welding end position” P2 which is the end of the weld bead formed by the preceding wire 3 The total welding torch moving distance L3 is calculated. Here, the “welding end position” and the “first crater processing start position” are the same position. Then, the welding torch is moved at a normal welding speed until the position of the trailing tip 2 reaches the welding end position P2 (first crater processing start position) from the welding start position P1. Then, a normal welding speed is applied from the welding end position P2 (first crater processing start position) to the second crater processing position P3, which is a position moved in the direction opposite to the welding direction by the first crater processing distance D1. The welding torch is moved at the first crater processing speed that is further reduced.
[0043]
The welding end method of Example 1 is a welding end method in which the feeding and energization of the trailing wire 4 are stopped and the preceding wire 3 performs the first and second crater processes, as shown in FIG. When the leading tip 1 reaches the welding end position P2, the feeding and energization of the trailing wire 4 are stopped, and the first crater process is slower than the normal welding speed while moving the welding torch in the direction opposite to the welding direction. The leading wire 3 performs the first crater processing at the first crater processing current value and the first crater processing voltage value at the speed,
Next, when the preceding wire 3 reaches the second crater processing position P3, the welding torch is stopped, the second crater processing current value and the second crater processing voltage value are started, and the second crater processing is started. This is a consumable two-electrode arc welding end method in which the measurement of the crater processing time is started and the second crater processing is ended when the measurement of the predetermined second crater processing time is completed.
[0044]
[Example 2]
Next, a second embodiment of the welding end control method and welding robot of the present invention will be described.
[Explanation of FIG. 14]
FIG. 14 shows that the leading tip 1 and the trailing tip 2 are angled with respect to the central axis of the nozzle 10 when the welding line WL used in the second embodiment is the X axis and the central axis of the nozzle 10 is the Y axis. It is a figure which shows the positional relationship of the leading wire front-end | tip 3a and the trailing-wire front-end | tip 4a when arrange | positioning.
In FIG. 14 in which the leading tip 1 and the trailing tip 2 are arranged at an angle with respect to the Y axis of the central axis of the nozzle 10, (1) the leading tip angle α is determined by the center axis of the leading tip 1 being the center Y of the nozzle. (2) The trailing tip angle β is an angle in which the central axis of the trailing tip 2 is inclined with the receding angle β to the center Y axis of the nozzle. 3 or the standard protruding length L1 (for example, 20 [mm]) of the trailing wire 4 is obtained when the leading wire 3 or the trailing wire 4 protrudes from the tip of the leading tip 1 or the trailing tip 2 by a predetermined length. The length of the leading wire 3 or the trailing wire 4 to the tip position (tool center position) of the leading wire 3 or the trailing wire 4 is as follows. Lead wire and rear wire when projecting length is standard projecting length L1 A wire tip distance between the wires, which are predetermined set value.
[0045]
[Explanation of FIG. 15]
FIG. 15 is a block diagram of the robot controller 27 when the welding end method or the welding end control method of the present invention is applied to the welding robot shown in FIG.
In FIG. 15, the work program file output circuit 29 stores (1) welding start parameters and (2) welding end parameters determined in advance in each welding section of the work piece 8.
Here, the above-mentioned “welding start parameter” means (1) the welding current value and welding voltage value of the preceding wire 3 and the succeeding wire 4 at the welding start position in each welding section, and (2) the normal welding speed. It is.
The “welding end parameter” is a condition for the first and second crater processing performed by the preceding wire 3, and (1) the first crater processing current value, the first crater processing voltage value, and (2). The moving speed of the welding torch in the direction opposite to the welding direction and the moving distance of the welding torch during the first crater processing period (D1 shown in FIG. 13), (3) the second crater processing current value, the second crater processing voltage value, and (4) A parameter consisting of the second crater processing time.
[0046]
In addition, the first crater processing distance D1 in the second embodiment may be set to, for example, (1) “distance between the wire tips of the standard protruding length” L2. Alternatively, (2) the moving time of the trailing wire and the welding torch during the first crater processing period may be set. In this case, (first crater processing distance) D1 = (moving speed of welding torch during first crater processing period) × (moving time of welding torch during first crater processing period). Alternatively, (3) “standard protrusion length distance between wire tips” L2 may be specified as a percentage and set by (first crater processing distance) D1 / L2 [%].
[0047]
Further, according to experiments by the inventors, when the molten pool is depressed to the extent that the molten pool trace 13 is formed as shown in FIG. 5 of the prior art 1, the molten pool of the preceding wire is filled with the depressed molten metal. Therefore, it is necessary to move the leading tip 1 in the direction opposite to the welding direction rather than the “standard protruding length distance between the wire tips” L2. Therefore, as shown in FIG. 13, the first crater processing distance D1 is longer than the “distance between the wire tips of the standard protruding length” L2.
[0048]
In the electrode parameter output circuit 31 shown in FIG. 15, when the leading wire 3 or the trailing wire 4 protrudes from the tip of the predetermined leading tip 1 or the trailing tip 2 shown in FIG. “Standard protruding length of the preceding wire 3 or the succeeding wire 4” L1 (for example, 20 [mm]) and {circle around (2)} which are the lengths up to the tip position (tool center position) of the preceding wire 3 or the following wire 4 An electrode composed of “the distance between the wire tips of the standard protruding length” L2, which is the distance between the wire tips of the preceding wire and the succeeding wire when the protruding length of the leading wire 3 or the trailing wire 4 is the standard protruding length L1. The parameter is memorized.
[0049]
Further, the welding torch movement path calculation circuit 32 receives the output signal of the work program file output circuit 29 and calculates each joint angle of the manipulator 21 for moving the welding torch from the welding start position to the welding end position. Then, the calculated value of each joint angle is output to a servo control circuit 33 described later.
[0050]
The servo control circuit 33 receives the calculated values of the joint angles of the manipulator 21 for moving the welding torch from the welding torch moving path calculation circuit 32 and controls the manipulator 21.
[0051]
The preceding wire welding condition output circuit 35 receives a preceding wire welding start command signal S1 that instructs the preceding wire 3 to energize the welding wire from the welding torch movement path calculation circuit 32 when the preceding tip 1 reaches a predetermined welding start position. When input, a signal instructing energization of the welding current of the welding current value of the preceding wire 3 output from the work program file output circuit 29 is output.
The preceding wire welding power source device 23 energizes the preceding wire 3 with a welding current when a signal instructing energization of the welding current of the preceding wire is input from the preceding wire welding condition output circuit 35.
[0052]
The trailing wire welding condition output circuit 36 starts the trailing wire welding in which the trailing tip 2 reaches a predetermined welding start position and instructs the trailing wire 4 to energize the welding wire 4 from the welding torch movement path calculation circuit 32. When the command signal S2 is input, a signal for instructing energization of the welding current of the welding current value of the succeeding wire 4 output from the work program file output circuit 29 is output.
The power supply device 24 for the subsequent wire welding supplies the welding current to the subsequent wire 4 when a signal instructing the energization of the welding current of the subsequent wire is input from the subsequent wire welding condition output circuit 36.
[0053]
[Example 2]
As shown in FIGS. 13, 17, and 18, the second embodiment stops the feeding and energization of the trailing wire 4 at the welding end position P <b> 2 and moves the welding torch in the direction opposite to the welding direction. A welding end control method and a welding robot in which the wire 3 performs the first crater process, and then performs the second crater process by substantially stopping the welding torch.
In the welding end control method of the second embodiment, as shown in FIG. 13, when the leading tip 1 reaches the welding end position P2, the feeding and energization of the trailing wire 4 are stopped and the welding torch is set in the welding direction. The preceding wire 3 performs the first crater processing at the first crater processing current value and the trailing wire first crater processing voltage value at the first crater processing speed slower than the normal welding speed while moving in the reverse direction, When the preceding wire 3 reaches the second crater processing position P3, the welding torch is stopped, and the second crater processing is started and the second crater processing time is started based on the second crater processing current value and the second crater processing voltage value. This is a consumable two-electrode arc welding end control method that ends the second crater processing when the measurement of the second crater processing time is completed.
[0054]
Next, the operation of the robot control apparatus 27 according to the second embodiment will be described with reference to the signal time chart of FIG. 16 and the flowcharts shown in FIGS. 17 and 18.
[Explanation of FIG. 16]
FIG. 16 is a diagram illustrating a signal output from the welding torch moving path calculation circuit 32 of the robot control apparatus according to the second embodiment and the moving speeds of the leading tip 1 and the trailing tip 2. In the same figure, (A) shows the elapsed time t of the preceding wire welding start command signal S1, and (B) shows the elapsed time t of the first crater processing command signal S11. ) Shows the elapsed time t of the second crater processing command signal S13, FIG. 4D shows the elapsed time t of the moving speed of the preceding chip 1 and the succeeding chip 2, and FIG. The time t of the welding start command signal S2 is shown, and FIG. 8F shows the time t of the trailing wire welding end processing command signal S10. Here, in order to simplify the explanation, it is assumed that the path between the welding start position and the welding end position in each welding section is taught by one straight line.
[0055]
[Explanation of FIGS. 17 and 18]
17 and 18 are flowcharts illustrating the operation of the robot control apparatus 27 according to the second embodiment. In step ST1 “electrode parameter setting step” shown in FIG. 17, the electrode parameter output circuit 31 is connected to (1) the standard protruding length L1 of the preceding wire 3 or the trailing wire 4 and (2) the leading wire 3 and the trailing wire 4. The electrode parameters including “standard wire protruding distance between wire tips” L2 are set.
[0056]
In step ST2 “work program file setting step”, predetermined (1) welding start parameter and (2) welding end parameter in each welding section of the work piece 8 are set in the work program file output circuit 29.
[0057]
At step ST3 “electrode parameter and crater processing work program file input step” shown in FIG. 17 and at time t1 shown in FIG. 16, the welding robot system is started and the electrode parameters set in the electrode parameter output circuit 31 and the work program file output A normal welding speed at a predetermined welding start position in each welding section of the workpiece 8 set in the circuit 29 is output to the welding torch movement path calculation circuit 32.
In addition, predetermined (1) welding current value and welding voltage value of the preceding wire 3 at the welding start position in each welding section and (2) first crater processing current value and first The crater processing voltage value, (3) the second crater processing current value, and the second crater processing voltage value are output to the preceding wire welding condition output circuit 35, and predetermined (1) each in each welding section of the work piece 8 to be welded. The welding current value and welding voltage value of the trailing wire 4 at the welding start position in the welding section are output to the trailing wire welding condition output circuit 36.
[0058]
In step ST4 “Welding start position welding torch movement path calculation, output step” shown in FIG. 17, the welding torch movement path calculation circuit 32 calculates each joint angle of the manipulator 21 for moving the welding torch to the welding start position. Thus, the calculated values of the joint angles are output to the servo control circuit 33.
[0059]
At step ST5 “leading wire and subsequent wire welding start signal output step” shown in FIG. 17 and at time t2 shown in FIG. 16, the welding torch moves to the welding start position, and the joint angle at the welding start position described in step ST4 When the calculated value is reached, the welding torch moving path calculation circuit 32 outputs the preceding wire welding start command signal S1 to the preceding wire welding condition output circuit 35, and the subsequent wire welding start command signal S2. It outputs to the condition output circuit 36.
[0060]
In step ST6 “leading wire and succeeding wire energization start step” shown in FIG. 17, the leading wire welding start command signal S1 is input to the leading wire welding condition output circuit 35, and the trailing wire welding start command signal S2 is input to the trailing wire. When input to the welding condition output circuit 36, the preceding wire welding condition output circuit 35 and the succeeding wire welding condition output circuit 36 respectively supply welding to the preceding wire 3 and the succeeding wire 4 at the welding start position. The current value and the welding voltage value are output to the preceding wire welding power supply device 23 and the subsequent wire welding power supply device 24 to energize the preceding wire 3 and the following wire 4, respectively.
[0061]
In step ST7 “Welding end position welding torch moving path calculation step” shown in FIG. 17, the preceding wire welding start command signal S1 is input to the preceding wire welding condition output circuit 35, and the following wire welding start command signal S2 is input to the following wire. After being input to the welding condition output circuit 36, the welding torch movement path calculation circuit 32 sends the first crater processing speed, which is the movement speed of the welding torch during the first crater processing period, and the welding from the work program file output circuit 29. The first crater processing distance (D1 shown in FIG. 13) in which the welding torch moves in the direction opposite to the direction and (2) the second crater processing time are input, and the manipulator 21 for moving the welding torch to the welding end position. Each joint angle is calculated.
[0062]
In step ST8 “leading wire and succeeding wire welding start completion signal output step”, when the arc 5 and the arc 6 are generated at the leading wire tip 3a and the trailing wire tip 4a, respectively, the leading wire welding condition output circuit 35 and after The row wire welding condition output circuit 36 outputs a preceding wire welding start completion signal S3 and a following wire welding start completion signal S4 to the welding torch movement path calculation circuit 32, respectively.
[0063]
In step ST9 “first crater processing start position welding torch moving step” shown in FIG. 18, the welding torch moving path calculation circuit 32 receives the preceding wire welding start completion signal S3 and the subsequent wire welding start completion signal S4. In addition, each joint angle of the manipulator 21 for moving the preceding tip 4 to the welding end position P2 (first crater processing start position) calculated by the welding torch moving path calculation circuit 32 in step ST7 shown in FIG. To 33. As a result, the manipulator 21 starts a linear operation at a preset normal welding speed and performs normal welding.
[0064]
At step ST10 “first crater processing command signal output step” shown in FIG. 18 and at time t3 shown in FIG. 16, the leading tip 1 moves to the welding end position P2 (first crater processing start position) and is shown in FIG. When the calculated value of the joint angle at the welding end position P2 (first crater processing start position) described in step ST7 is reached, the welding torch movement path calculation circuit 32 executes the following wire welding end processing command signal S10. The output is output to the wire welding condition output circuit 36, and the first crater processing command signal S11 is output to the preceding wire welding condition output circuit 35.
Further, the welding torch moving path calculation circuit 32 outputs the first crater processing speed to the servo control circuit 33, and the servo control circuit 33 moves the welding torch in the direction opposite to the welding direction.
[0065]
In step ST11 “following wire welding end processing step” shown in FIG. 18 and time t3 shown in FIG. 16, the following wire welding condition output circuit 36 sends a following wire welding end processing command signal S10 from the welding torch movement path calculation circuit 32. Is input, the power supply device 24 for subsequent wire welding performs an anti-stick process and a welding release process. Then, after the end of the anti-stick process and the welding release process, the succeeding wire welding condition output circuit 36 outputs a succeeding wire welding end process completion signal S12 to the welding torch movement path calculation circuit 32 when it is determined that there is no welding. .
Here, the anti-stick process means that the motor feeds the wire by the inertial force even after the stop signal is input to the wire feeding device. Therefore, when the wire rushes into the molten pool and the molten pool cools, the tip of the wire adheres (sticks) to the weld metal. In order to prevent this sticking, after a stop signal is input to the wire feeder, a current smaller than the welding current value is applied to continue melting the wire and prevent the wire from being pushed into the molten pool. It is.
In the welding release process, for example, a short-circuit detection circuit or a welding current relay detects whether or not the tip of the wire is welded to the workpiece after energization of the wire is completed. And when welding is detected, it is the process which applies a no-load voltage between the front-end | tip of a wire and a to-be-welded object, energizes, burns up a wire, and cancels welding.
[0066]
In step ST12 “first crater processing step” shown in FIG. 18, when the preceding wire welding condition output circuit 35 receives the first crater processing command signal S11, the preceding wire welding condition output circuit 35 The processing current value and the first crater processing voltage value are output to the power supply device 23 for preceding wire welding.
[0067]
In step ST13 “second crater process start step” shown in FIG. 18 and time t4 shown in FIG. 16, the welding torch moves in the direction opposite to the welding direction, and the first calculation shown in FIG. 13 calculated in step ST7 shown in FIG. When the calculated value of the joint angle at the two crater processing position P3 is reached, the servo control circuit 33 stops the manipulator, and the welding torch movement path calculation circuit 32 outputs the second crater processing command signal S13 as the preceding wire welding condition output. Output to the circuit 35.
[0068]
In step ST14 “second crater processing step” shown in FIG. 18, when the preceding wire welding condition output circuit 35 receives the second crater processing command signal S13, the preceding wire welding condition output circuit 35 The processing current value and the second crater processing voltage value are output to the preceding wire welding power supply device 23, and measurement of the second crater processing time is started.
[0069]
In step ST15 “preceding wire welding end processing step” shown in FIG. 18, when the preceding wire welding condition output circuit 35 has finished measuring the second crater processing time, the preceding wire welding power supply 23 detects the preceding wire antistic. Processing and welding release processing are performed. When the preceding wire welding condition output circuit 35 determines that the preceding wire 3 is not welded after the anti-stick processing and the welding release processing are completed, the preceding wire welding end processing completion signal S14 is output to the welding torch movement path calculation circuit 32. To do.
[0070]
In step ST16 “next welding section welding step” shown in FIG. 18, when the welding torch movement path calculation circuit 32 receives the preceding wire welding end processing completion signal S14 and the succeeding wire welding end processing completion signal S12, FIG. Step ST4 to step ST15 shown in FIG. 18 are repeated to perform welding in the next welding section, and when the welding of all the welding sections set in the work program file output circuit 29 is finished, the activation of the welding robot is stopped. .
[0071]
The welding end control method of the second embodiment described above is summarized as follows. In the welding end control method of the second embodiment, the electrode parameter output circuit 31 includes (1) the standard protruding length L1 of the preceding wire 3 or the succeeding wire 4 and (2) “standard protruding length of the preceding wire 3 and the succeeding wire 4”. “Electrode parameter setting step” (step ST1) for setting electrode parameters including the distance between the wire tips “L2”;
A “work program file setting step” (step ST2) for setting (1) welding start parameters and (2) welding end parameters determined in advance in each welding section of the work piece 8 in the work program file output circuit 29;
The welding robot system is activated, and the electrode parameters set in the electrode parameter output circuit 31 and the normal welding speed at a predetermined welding start position in each welding section of the workpiece 8 set in the work program file output circuit 29 are obtained. It outputs to the welding torch movement path calculation circuit 32, and (1) the welding current value and welding voltage value of the preceding wire 3 at the welding start position in each welding section determined in advance in each welding section of the workpiece 8 and (2) The first crater processing current value and the first crater processing voltage value and (3) the second crater processing current value and the second crater processing voltage value are output to the preceding wire welding condition output circuit 35, and each welding of the workpiece 8 is performed. (1) In the section, the welding current value and welding voltage value of the succeeding wire 4 at the welding start position in each welding section are output to the succeeding wire welding condition output circuit 36. Parameters and crater processing work program file input step "(step ST3),
The welding torch moving path calculation circuit 32 calculates each joint angle of the manipulator 21 for moving the welding torch to the welding start position, and outputs the calculated value of each joint angle to the servo control circuit 33 “Welding start position welding”. Torch travel route calculation and output step "(step ST4),
When the welding torch reaches the welding start position, the welding torch movement path calculation circuit 32 outputs the preceding wire welding start command signal S1 to the preceding wire welding condition output circuit 35, and the subsequent wire welding start command signal S2 A "preceding wire and succeeding wire welding start completion signal output step" (step ST5) to be output to the row wire welding condition output circuit 36;
When the preceding wire welding start command signal S1 is input to the preceding wire welding condition output circuit 35 and the following wire welding start command signal S2 is input to the following wire welding condition output circuit 36, the preceding wire welding condition output circuit 35 And the succeeding wire welding condition output circuit 36 supplies the welding current value and the welding voltage value supplied to the preceding wire 3 and the succeeding wire 4 at the welding start position, respectively, for the preceding wire welding power source device 23 and the succeeding wire welding. The power is supplied to the power supply device 24 to energize the preceding wire 3 and the succeeding wire 4 respectively, and the welding torch movement path calculation circuit 32 outputs the normal welding speed to the servo control circuit 33. Step "(Step ST6),
After the preceding wire welding start command signal S1 is input to the preceding wire welding condition output circuit 35 and the subsequent wire welding start command signal S2 is input to the subsequent wire welding condition output circuit 36, the welding torch moving path calculation circuit 32 (1) The first crater in which the welding torch moves in the direction opposite to the welding direction and the first crater processing speed that is slower than the normal welding speed at the moving speed of the welding torch during the first crater processing period from the work program file output circuit 29 The processing distance D1 and {circle around (2)} second crater processing time are input, and each joint angle of the manipulator 21 for moving the welding torch to the welding end position is calculated. Step ST7)
When the arc 5 and the arc 6 are generated at the leading wire tip 3a and the trailing wire tip 4a, respectively, the leading wire welding condition output circuit 35 and the trailing wire welding condition output circuit 36 indicate the leading wire welding start completion signal S3 and the trailing line. A “preceding wire and succeeding wire welding start completion signal output step” (step ST8) for outputting the wire welding start completion signal S4 to the welding torch movement path calculation circuit 32, respectively;
When the welding torch movement path calculation circuit 32 receives the preceding wire welding start completion signal S3 and the subsequent wire welding start completion signal S4, the welding torch movement path calculation circuit 32 sets the welding end position P2 calculated in step ST7. “First crater processing start position welding torch moving step” (step ST9) for outputting each joint angle of the manipulator 21 for moving the preceding chip 4 to the servo control circuit 33;
When the leading tip 1 reaches the welding end position P2, the welding torch movement path calculation circuit 32 outputs a trailing wire welding end processing command signal S10 to the trailing wire welding condition output circuit 36, and the first crater processing command The signal S11 is output to the preceding wire welding condition output circuit 35, the welding torch movement path calculation circuit 32 outputs the first crater processing speed to the servo control circuit 33, and the servo control circuit 33 reverses the welding torch in the welding direction. “First crater processing command signal output step” (step ST10) to be moved to
When the succeeding wire welding condition output circuit 36 receives the succeeding wire welding end processing command signal S10 from the welding torch movement path calculation circuit 32, the succeeding wire welding power source device 24 performs the anti-stick process and the welding release process. When the subsequent wire welding condition output circuit 36 determines that the succeeding wire 4 is not welded, the welding torch movement path calculation circuit 32 completes the succeeding wire welding end process. “Subsequent wire welding end processing step” (step ST11) for outputting the signal S12;
When the preceding wire welding condition output circuit 35 receives the first crater processing command signal S11, the preceding wire welding condition output circuit 35 outputs the first crater processing current value and the first crater processing voltage value to the power source for preceding wire welding. “First crater processing step” (step ST12) to be output to the device 23;
When the welding torch moves in the direction opposite to the welding direction and reaches the second crater processing position P3, the servo control circuit 33 stops the manipulator, and the welding torch movement path calculation circuit 32 receives the second crater processing command. A “second crater processing start step” (step ST13) for outputting the signal S13 to the preceding wire welding condition output circuit 36;
When the preceding wire welding condition output circuit 35 receives the second crater processing command signal S13, the preceding wire welding condition output circuit 35 outputs the second crater processing current value and the second crater processing voltage value to the power source for preceding wire welding. “Second crater processing step” (step ST14) that is output to the device 23 and starts measuring the second crater processing time;
When the preceding wire welding condition output circuit 35 completes the measurement of the second crater processing time, the preceding wire welding power source device 23 performs the anti-stick process and the welding release process of the preceding wire, and the preceding wire welding condition output circuit 35 A consumable two-electrode arc consisting of a “preceding wire welding end processing step” (step ST15) that outputs a preceding wire welding end processing completion signal S14 to the welding torch movement path calculation circuit 32 when it is determined that the preceding wire 3 is not welded. This is a welding end control method.
[0072]
The welding robot of the second embodiment to which the welding end control method is applied is summarized as follows. The welding robot of the second embodiment includes a work program file output circuit 29 for storing (1) welding start parameters and (2) welding end parameters determined in advance in each welding section of the workpiece 8;
An electrode parameter output circuit 31 for storing electrode parameters consisting of a predetermined protrusion length L1 of the preceding wire 3 or the succeeding wire 4 and a distance L2 between the wire protrusions of the reference protrusion length 2;
(1) When the output signal of the work program file output circuit 29 is inputted, each joint angle of the manipulator 21 for moving the welding torch from the welding start position to the welding end position is calculated (in a servo control circuit 33 described later). ) Output the calculated value of each joint angle. (2) When the welding torch reaches the welding start position, it outputs the preceding wire welding start command signal S1 to the preceding wire welding condition output circuit 35, which will be described later. A row wire welding start command signal S2 is output to (following wire welding condition output circuit 36, which will be described later), and a normal welding speed is output to (servo control circuit 33, which will be described later). When the position P2 is reached, the subsequent wire welding end processing command signal S10 is output (to a subsequent wire welding condition output circuit 36 described later), and the first crater processing command signal S11 is output. The first crater processing speed slower than the normal welding speed is output to (servo control circuit 33 described later), and (4) the preceding chip 1 is subjected to the second crater processing. A welding torch movement path calculation circuit 32 that outputs a second crater processing current value and a second crater processing voltage value (to a preceding wire welding condition output circuit 36 described later) when the position P3 is reached;
(1) When a calculated value of each joint angle of the manipulator 21 for moving the welding torch is input from the welding torch moving path calculation circuit 32 to control the manipulator 21, and (2) when the first crater processing speed is input And (3) a servo control circuit 33 for stopping the manipulator when the leading tip 1 reaches the second crater processing position P3 by moving the welding torch in the direction opposite to the welding direction;
(1) When the preceding wire welding start command signal S1 is input, a signal for instructing the energization of the welding current of the preceding wire 3 is output (to a power supply device for preceding wire welding 23 described later), and (2) the preceding wire When the arc 5 is generated at the tip 3a, the preceding wire welding start completion signal S3 is output to the welding torch movement path calculation circuit 32. (3) When the first crater processing command signal S11 is input, the first crater When the processing current value and the first crater processing voltage value are output (to the power supply device for preceding wire welding 23 described later) and the second crater processing command signal S13 is input, the second crater processing current value and When the second crater processing voltage value is output (to a power supply device for preceding wire welding 23 described later), measurement of the second crater processing time is started, and (5) the measurement of the second crater processing time is completed. In addition, a command signal for performing anti-stick processing and welding release processing of the preceding wire is output (to the power device 23 for preceding wire welding described later), and when it is determined that the preceding wire 3 is not welded, a welding torch movement path calculation circuit A preceding wire welding condition output circuit 35 for outputting a preceding wire welding end processing completion signal S14 to 32,
When a signal instructing energization of the welding current of the preceding wire 3 is input from the preceding wire welding condition output circuit 35, the welding current is energized to the preceding wire 3, and the preceding wire 3 performs anti-stick processing and welding release processing. When a command signal is input, the preceding wire 3 performs an anti-stick process and a welding release process, and a preceding wire welding power supply device 23;
(1) When the succeeding wire welding start command signal S2 is input, a signal for commanding the energization of the welding current of the succeeding wire 4 is output (to a power device 24 for succeeding wire welding described later), and (2) When the arc 6 is generated at the trailing wire tip 4a, the trailing wire welding start completion signal S4 is output to the welding torch movement path calculation circuit 32, and the trailing wire welding end processing command signal S10 is input. When the succeeding wire 4 outputs an instruction signal for performing anti-stick processing and welding release processing (to the power device 24 for the succeeding wire welding described later), and when it is determined that the succeeding wire 4 is not welded, A trailing wire welding condition output circuit 36 for outputting a trailing wire welding end processing completion signal S12 to the welding torch moving path calculation circuit 32;
When a signal instructing energization of the welding current of the succeeding wire 4 is input from the succeeding wire welding condition output circuit 36, the succeeding wire 4 is energized with the welding current, and the succeeding wire 4 is subjected to anti-stick treatment and welding. The welding robot includes a power supply device for subsequent wire welding that performs an anti-stick process and a welding release process for the subsequent wire 4 when a command signal for performing the release process is input.
[0073]
【Effect of the invention】
The consumable two-electrode arc welding end method, the welding end control method and the welding robot according to the present invention supply and energize the trailing wire 4 at the welding end position P2 in the two-electrode one-torch consumable electrode arc welding end method. Stop, move the welding torch in the direction opposite to the welding direction at a slower welding speed than during normal welding, perform the first crater treatment only with the preceding wire 3, and then substantially stop the movement of the welding torch. Since the second crater process is performed, there is only one crater process trace, the appearance of the weld bead is improved even at the welding end position, and the weld joint strength can be ensured. In addition, when performing high-speed welding, crater treatment can also be performed on the depressed molten pool before performing crater treatment, so there is no weld pool mark at the welding end position, and there are defects such as cracks and shrinkage holes. It does not occur.
Furthermore, even when fillet welding is performed on a bottom plate having a box shape and a wall in front of the welding end position P2 in the welding direction, a uniform weld bead 9 can be obtained.
[Brief description of the drawings]
FIG. 1 is a diagram that best represents the features of the invention according to the present application;
FIG. 2 is a diagram for explaining a consumable electrode arc welding end method of a two-electrode one-torch method.
FIG. 3 is a diagram showing a general configuration of a two-electrode, one-torch welding robot.
FIG. 4 is a diagram for explaining a method of ending consumable electrode arc welding by a two-electrode one-torch method according to prior art 1;
FIG. 5 is a diagram for explaining a method of ending consumable electrode arc welding of the conventional electrode 1 of the conventional technique 1 following FIG. 4;
FIG. 6 is a view showing an apparatus for performing tandem arc welding according to prior art 2;
FIG. 7 is a time chart for explaining a control method at the end of welding according to the prior art 2;
FIG. 8 is a diagram for explaining a case where the shape of a work piece 8 is box-shaped and fillet welding of a bottom plate is performed.
FIG. 9 is a diagram for explaining that the weld bead 9 is non-uniform at the welding end position P2 when the shape of the workpiece 8 is box-shaped and fillet welding of the bottom plate is performed according to the related art 2. .
FIG. 10 illustrates a case where the leading wire 3 and the trailing wire 4 are fed and the leading wire 3 performs the first and second crater processes in the consumable two-electrode arc welding end method according to the first embodiment of the present invention. FIG.
11 is a diagram illustrating a welding end method subsequent to FIG. 10 in the welding end method of Example 1. FIG.
FIG. 12 is a diagram for explaining a case where the shape of a work to be welded 8 is box-shaped and fillet welding of a bottom plate is performed by the welding end method of the first embodiment.
FIG. 13 is a diagram for explaining the moving distance of the welding torch from the welding start position P1 to the first crater processing start position and the second crater processing position when the preceding wire 3 of the present invention performs crater processing.
FIG. 14 provides an angle for the leading tip 1 and the trailing tip 2 with respect to the central axis of the nozzle 10 when the welding line WL used in Example 2 is the X axis and the central axis of the nozzle 10 is the Y axis. It is a figure which shows the positional relationship of the leading wire front-end | tip 3a and the trailing-wire front-end | tip 4a when arrange | positioning.
15 is a block diagram of a robot control device 27 when the welding end method or the welding end control method of the present invention is applied to the welding robot shown in FIG. 3;
FIG. 16 is a diagram illustrating a signal output from a welding torch movement path calculation circuit 32 of the robot control apparatus according to the second embodiment and movement speeds of the leading tip 1 and the trailing tip 2;
FIG. 17 is a flowchart illustrating the operation of the robot control apparatus 27 according to the second embodiment.
FIG. 18 is a flowchart showing the operation of the robot control apparatus 27 of the second embodiment following FIG.
[Explanation of symbols]
1 Leading chip
2 trailing chip
3 Lead wire
3a Lead wire tip
4 trailing wire
4a Trailing wire tip
5, 6 arc
7 molten pool
8 Workpiece
9 Weld beads
10 nozzles
11 Shield gas
13 molten pool trace
14 Welding torch
15, 16 Crater processing trace
21 Manipulator
23 Power supply device for leading wire welding
24 Power supply device for trailing wire welding
25 Lead wire feeder
26 Trailing wire feeder
27 Robot controller
29 Work program file output circuit
31 Electrode parameter output circuit
32 Welding torch movement path calculation circuit
33 Servo control circuit
35 Lead wire welding condition output circuit
36 Subsequent wire welding condition output circuit
41 Leading chip
42 Trailing chip
44 Power supply device for leading wire welding
45 Power supply device for trailing wire welding
46 Lead wire feeder
47 Subsequent wire feeder
48 Lead wire
49 trailing wire
50, 51 arc
52 molten pool
53 Weld Bead
54 Welding control device
55 Welding Robot
D1 First crater processing distance
L1 Standard protruding length of leading wire 3 or trailing wire 4
L2 Standard overhanging distance between wire tips
L3 Total welding torch travel distance
P1 Welding start position
P2 Welding end position
P3 Second crater processing position
S1 Lead wire welding start command signal
S2 Subsequent wire welding start command signal
S3 Lead wire welding start completion signal
S4 Subsequent wire welding start completion signal
S5 Lead wire welding end processing command signal
S10 Subsequent wire welding end processing command signal
S11 First crater processing command signal
S12 Subsequent wire welding end processing completion signal
S13 Second crater processing command signal
S14 Leading wire welding end processing completion signal
α Leading tip angle
β trailing tip angle

Claims (4)

  In a consumable two-electrode arc welding end method in which two wires are fed and welded in one torch, feeding and energization of the trailing wire are stopped at the welding end position, and the welding torch is moved in the direction opposite to the welding direction. Consumable two electrodes where the leading wire performs the first crater process while moving the first crater processing distance at a speed slower than the normal welding speed, and then stops the movement of the welding torch and the leading wire performs the second crater process How to end arc welding.   The consumable two-electrode arc welding end method, wherein the first crater processing distance according to claim 1 is a distance between wire tips of a standard protruding length.   A consumable two-electrode arc welding end method for calculating the first crater processing distance according to claim 1 from the first crater processing moving speed and the first crater processing moving time. In a consumable two-electrode arc welding end method in which two wires are fed and welded in one torch, the feeding and energization of the succeeding wire are stopped when the leading tip reaches the welding end position, and the welding torch The preceding wire performs the first crater treatment at the first crater treatment current value and the first crater treatment voltage value at the first crater treatment speed that is slower than the normal welding speed while moving the wire in the direction opposite to the welding direction,
Next, when the preceding wire reaches the second crater processing position, the welding torch is stopped, the second crater processing is started by the second crater processing current value and the second crater processing voltage value, and a predetermined second A consumable two-electrode arc welding end method for starting measurement of crater processing time and ending the second crater processing when the measurement of the second crater processing time is completed.

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