JP2009190062A - Welding robot apparatus, and automatic welding method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a welding robot apparatus and an automatic welding method by which an automatic welding can be restarted from a portion, where the welding has been interrupted, even when a welding abnormality is caused to interrupt the welding operation. <P>SOLUTION: The welding robot apparatus is provided with a welding torch at the top end of an arm, and automatically welds a plurality of welded joints successively. When abnormality is detected during the welding, whether or not the detected abnormality is the predetermined abnormality whose cause can be specified is determined. When it is determined as the predetermined abnormality, the welding operation is interrupted, and the welded joint, in which the welding abnormality has been detected and the welding operation has been interrupted, the welding pass and welding interruption position, where the welding has been interrupted in the welded joint, and welding interruption data with respect to the path of the interrupted welding pass are stored. Then, depositions stuck to the nozzle of the welding torch are removed, and then the interrupted position of a weld bead terminal is specified, thereby performing a rewelding from the weld bead termination. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a welding robot apparatus and an automatic welding method for performing re-welding from a welding interruption position after detecting an abnormality occurring during automatic welding and interrupting welding.

  Patent Documents 1 and 2 disclose inventions related to automatic welding that are intended to avoid an increase in the labor of a worker accompanying a welding abnormality that occurs during automatic welding using a welding robot and a reduction in work efficiency.

  Patent Document 1 discloses an invention related to welding abnormality processing that can eliminate the cause of arc breakage without causing complication of teaching work even when arc breakage occurs during automatic welding. ing. In this welding abnormality processing method, when an arc break occurs during automatic welding, the welding torch is moved on a predetermined welding line while the arc is broken, and the tip of the welding wire is cut at a previously taught abnormality processing position to perform the abnormality treatment. It is characterized in that the welding is performed again from the beginning of the welding line.

  Further, Patent Document 2 discloses an invention relating to automatic operation of a welding robot apparatus that can reduce the amount of work required for repairing a welding abnormality location by preventing the recurrence of welding abnormality in advance. In this automatic operation method, if an abnormality occurs during automatic welding, the automatic welding is temporarily interrupted to eliminate the cause of the welding abnormality, then the welded joint where the welding abnormality has occurred is skipped and welding is resumed from the next welded joint. There is a feature in the point to do.

JP-A-6-335771 JP 2002-292468 A

  However, in the invention described in Patent Document 1, a welding failure may occur during re-welding due to a slag formed at the welding start end, a burnout during welding, or the like. In addition, assembling of large members such as steel frames is generally multi-layer welding, but when multi-layer welding is performed, the invention described in Patent Document 1 is used on the weld bead formed halfway. New welding will be performed, resulting in poor working efficiency and excessive weld beads.

  Further, in the invention described in Patent Document 2, it is necessary for an operator to find a weld bead in which a welding abnormality has occurred and determine how far the weld bead has been formed. Therefore, in order to continue the interrupted welding, it is necessary to perform the welding by manually operating the welding robot, or the operator needs to perform the welding manually, and the work efficiency is poor.

  The present invention has been made in view of such a problem, and even if a welding abnormality occurs and a welding operation is interrupted, a welding robot apparatus capable of resuming automatic welding from a position where welding is interrupted, and an automatic An object is to provide a welding method.

  A welding robot apparatus according to the present invention is a welding robot apparatus having a welding torch at the tip of an arm, and performing welding by moving the arm freely with respect to a workpiece to be welded, which occurred during welding of the workpiece. A welding abnormality detecting means for detecting a welding abnormality, a welding abnormality determining means for determining whether the welding abnormality detected by the welding abnormality detecting means is a predetermined abnormality capable of specifying a factor causing the welding abnormality, and the welding When an abnormality is detected, the welding interruption means for interrupting the welding operation, the welding data storage means for storing the welding interruption data that is data relating to the interrupted welding, and the welding interruption data stored in the welding data storage means A welding interruption position specifying means for specifying the end of the interrupted welding bead, and the welding bead specified by the welding interruption position specifying means. And performing re-welding the end of the de.

  When the welding abnormality determining means determines that the welding abnormality is a predetermined abnormality, it may further include a nozzle cleaning device that removes deposits adhering to the nozzle of the welding torch.

  The welding interruption data may be data relating to a welding incomplete joint in which a welding abnormality is detected, a welding path in which welding is interrupted in the welding incomplete joint, an end position of the welding path, and a locus of the welding path. .

  An automatic welding method according to the present invention is an automatic welding method in which a welding torch is provided at the tip of an arm, and the arm is freely moved with respect to a workpiece to be welded to weld a plurality of joints. Welding the joints in sequence, suspending the welding when a welding abnormality is detected, storing the welding interruption data, which is data related to the interrupted welding, skipping the joint where the welding abnormality is detected, and welding from the next joint Welding operation is repeated until all joints are carried out, and if there is a detected welding abnormality, the welded abnormal part is repaired by the operator, then welding is performed for each joint where welding has been interrupted from the stored welding interruption data. The position of the end of the bead is specified, and re-welding is performed from the end of the weld bead.

  When the welding abnormality is detected and the welding is interrupted, it is determined whether the welding abnormality is a predetermined abnormality that can identify a factor causing the welding abnormality, and when the welding abnormality is determined to be a predetermined abnormality, You may make it remove the deposit | attachment adhering to the nozzle of the welding torch.

  The welding interruption data may be data relating to a welding incomplete joint in which a welding abnormality is detected, a welding path in which welding is interrupted in the welding incomplete joint, an end position of the welding path, and a locus of the welding path. .

  According to the present invention, even if the welding operation is interrupted and the welding operation is interrupted, the automatic welding can be resumed from the position where the welding is interrupted, so that the efficiency of the welding operation can be improved and a good welding bead can be obtained. Can be formed.

  Hereinafter, the best mode for carrying out the welding robot apparatus and the automatic welding method of the present invention will be described in detail with reference to FIGS.

  As shown in FIG. 1, a welding robot apparatus 1 according to an embodiment of the present invention includes a welding power source 10, a robot main body 30 that performs welding on a workpiece (not shown) to be welded, and a wrist tip of the robot main body 30. It comprises a welding torch 11 (not shown), a nozzle cleaning device 20 that cleans the nozzles of the welding torch 11, and a welding robot control device 40 that controls these various devices. Note that the welding robot apparatus 1 may include a positioner and a slider (moving device) so that each weld joint of the workpiece has an appropriate welding posture within the operation range of the robot body 30.

  The welding power source 10 receives a welding start / end command, a welding current / voltage welding condition command, and the like from a welding power source control unit 81 described later, and supplies welding power to the welding torch 11. Further, the welding power source 10 detects a welding current during welding and transmits a welding current detection signal (WCR) to the welding power source control unit 81. The welding power source 10 also serves as a sensing power source.

  The welding torch 11 is supplied with electric power from the welding power source 10 and generates an arc with the workpiece. The wire fed out from the welding torch 11 is supplied from a wire feeding device (not shown). Further, carbon dioxide gas for shielding the arc is supplied to the welding torch 11 from a carbon dioxide supply device (not shown).

  The nozzle cleaning device 20 is a device for removing spatter and the like adhering to the nozzle of the welding torch 11, and is installed within the operation range of the robot body 30. The nozzle cleaning device 20 receives a cleaning start / end command or the like from a nozzle cleaning device control unit 82 described later, and removes spatter and the like attached to the welding torch 11.

  The robot body 30 includes an arm (not shown) and has a vertical articulated structure having six degrees of freedom so that the angle of the welding torch 11 attached to the tip can be freely set. The robot body 30 includes a DC motor (not shown) and a position detector that cause the arm to perform a predetermined operation. The robot body 30 receives a command from a robot body control device 70 described later, operates the arm, and causes the tip of the welding torch 11 to perform a predetermined operation based on teaching data described later.

  The robot control device 40 includes an arithmetic processing device 50, a storage device 60, a robot main body control device 70 that controls the robot main body 30, an external control device 80 that controls an external device such as the welding power source 10, and an external device when welding is abnormal. It comprises a welding abnormality detection control unit 83 that detects the welding abnormality by controlling the apparatus, and an input device 90 for an operator to input work data.

  The arithmetic processing device 50 includes an operation arithmetic processing unit 51, an abnormality arithmetic processing unit 52, and a re-execution arithmetic processing unit 53.

  The motion calculation processing unit 51 performs a calculation process for obtaining an operation performed by the robot body 30 from a command from the input device 90 or a teaching program stored in a teaching program storage unit 61 described later. The obtained arithmetic processing result is transmitted to the robot main body control device 70, and the robot main body control device 70 controls the robot main body 30 based on the transmitted arithmetic processing result. Further, the operation calculation processing unit 51 performs calculation processing for obtaining operations of the welding power source 10 and the nozzle cleaning device 20 from a command from the input device 90 and a teaching program stored in a teaching program storage unit 61 described later. . Then, the obtained arithmetic processing result is transmitted to the external control unit 80, and the external control unit 80 controls the welding power source 10 and the nozzle cleaning device 20 based on the transmitted arithmetic processing result. Specifically, the operation calculation processing unit 51 controls the operation of the welding power source 10 via the welding power source control unit 81 described later on the welding related data in each teaching program stored in the teaching program storage unit 61. To do. Further, the operation calculation processing unit 51 controls the operation of the nozzle cleaning device 20 through nozzle cleaning device control unit 82 described later, with respect to nozzle cleaning related data in each teaching program stored in the teaching program storage unit 61. To do. Here, the teaching program is a program that stores the operation of the robot. In the above teaching program, in addition to a program such as a welding sequence, posture, and condition for performing actual welding, a work position and an opening are also included. A program for executing sensing for detecting the tip position, a retreat program after occurrence of an abnormality, a nozzle cleaning program at the retreat position, and a backward program from the retreat position are included.

  In addition, when a welding abnormality is detected, the operation calculation processing unit 51 receives a welding interruption command from the abnormality calculation processing unit 52, and temporarily calculates the reproduction operation of the robot main body 30 via the robot main body control device 70. I do. Then, the operation calculation processing unit 51 performs a retraction program after occurrence of an abnormality, a nozzle cleaning program at the retraction position, a retrograde program from the retraction position, and welding of the next welded joint, which are stored in a teaching program storage unit 61 described later. Arithmetic processing is performed in the order of operation programs to be performed, and the reproduction operation of the robot body 30 is continued via the robot body controller 70. Further, the operation calculation processing unit 51 detects the welded joint where the welding operation is interrupted, the welding path interrupted in the welded joint, and the welding interrupt position, and the data related to the trajectory of the welding path is also transmitted to the welding abnormality detection control unit. 83. Then, the operation calculation processing unit 51 transmits the welding interruption data obtained in this way to the welding interruption data storage unit 63 described later. Further, the motion calculation processing unit 51 receives a command to end the reproduction operation from the abnormality calculation processing unit 52, and ends the reproduction operation of the robot main body 30 via the robot main body control device 70.

  Further, the operation calculation processing unit 51 receives a re-execution processing instruction from the re-execution calculation processing unit 53, and executes calculation processing for obtaining an operation at the time of re-welding of the robot main body 30 via the robot main body control device 70. To do. In addition, the operation calculation processing unit 51 executes calculation processing for obtaining an operation at the time of re-welding of the welding power source 10 via the welding power source control unit 81.

  The abnormality calculation processing unit 52 receives various abnormality detection signals from a welding abnormality detection control unit 83 to be described later, and outputs a welding interruption command for the reproduction operation of the robot body 30 to the operation calculation processing unit 51. Further, the abnormality calculation processing unit 52 determines whether or not the received various abnormality detection signals match any one of the skip conditions stored in the skip condition storage unit 62 described later. If the result of this determination calculation matches the skip condition, the abnormality calculation processing unit 52 outputs the above-described abnormality processing detection command for obtaining the welding interruption data to the operation calculation processing unit 51. Then, the abnormality calculation processing unit 52 receives a calculation result from the operation calculation processing unit 51 as to whether there is a weld line to be welded following the weld line in which the welding abnormality has occurred. When the abnormality calculation processing unit 52 obtains a determination calculation result that does not match the skip condition and a calculation result without a weld line following the abnormal weld line, the abnormality calculation processing unit 52 outputs a reproduction operation end command to the operation calculation processing unit 51. To do. If a calculation result that does not match the skip condition is obtained, an unexpected welding abnormality may have occurred, or a welding abnormality that cannot be solved by cleaning the nozzle may have occurred. Because there is.

  The re-execution calculation processing unit 53 sends a re-execution processing command to the operation calculation processing unit 51 based on the welding interruption data stored in the welding interruption data storage unit 63 when re-welding the welded joint in which the welding abnormality has occurred. Output.

  The storage device 60 includes a teaching program storage unit 61 that stores a teaching program and the like, a skip condition storage unit 62 that stores conditions for skipping a welding line when welding abnormality occurs, and a welding interruption data storage unit 63 that stores welding interruption data. It consists of and.

  The teaching program storage unit 61 stores a teaching program for each workpiece that is a work target input by the operator using the input device 90. The teaching program storage unit 61 stores a retraction program after the occurrence of an abnormality, a nozzle cleaning program at the retreat position, and a retrograde program from the retreat position.

  The skip condition storage unit 62 stores the skip condition input by the operator using the input device 90. For example, the “skip during welding”, which is a skip condition when “abnormal welding welding” described later occurs, “nozzle” described later. When "Welding" and "Sensing" are skipping conditions when "Contact Abnormality" occurs, "Welding" is skipping condition when "Arc Abnormality" described later occurs, and "Sensing Error" described later occurs "Sensing" is memorized. This skip condition is a condition of a welding abnormality that can identify the cause of the welding abnormality. In this embodiment, as will be described later, this skip condition is caused by spatter or the like excessively attached to the nozzle of the welding torch 11. It is a welding abnormality.

  The welding interruption data storage unit 63 detects the welding joint in which the welding operation is interrupted detected by the operation calculation processing unit 51, data on the welding path and welding interruption position interrupted in the welding joint, and the welding tracing abnormality detection control unit 84. And the data relating to the trajectory of the interrupted welding path detected by.

  The robot body control device 70 receives a command based on the teaching program sent from the motion calculation processing unit 51 and controls the robot body 30. Further, the reproduction operation of the robot main body 30 is temporarily suspended by the welding interruption command transmitted from the operation calculation processing unit 51, and the reproduction operation of the robot main body 30 is continuously controlled by the release command. Further, the regenerating operation of the robot main body 30 is controlled by the re-welding command of the welding abnormal portion transmitted from the operation calculation processing unit 51.

  The external control device 80 includes a welding power source control unit 81 and a nozzle cleaning device control unit 82. The welding power source control unit 81 controls the welding power source 10 according to the operation start / interruption command of the welding power source 10 based on the teaching program from the operation calculation processing unit 51, and controls the welding torch based on the welding current and voltage data. The welding current / voltage applied to the wire 11 and the wire feed amount are controlled.

  The nozzle cleaning device control unit 82 controls the operation / interruption of the nozzle cleaning device 20 according to the operation start / interruption command of the nozzle cleaning device 20 based on the teaching program from the operation calculation processing unit 51.

  The welding abnormality detection control unit 83 includes a welding scanning abnormality detection control unit 84, a nozzle contact detection control unit 85, an arc abnormality detection control unit 86, and a sensing error detection control unit 87.

  When the welding scanning abnormality detection control unit 84 receives a “welding copying abnormality” signal transmitted from an arc sensor (not shown) when the welding position deviates from the welding line to an allowable range abnormality, the abnormality calculation processing unit 52 “ An occurrence signal of “welding profiling abnormality” is transmitted. Further, the welding scanning abnormality detection control unit 84 detects the locus of the welding path and the like according to the abnormality processing detection command from the abnormality calculation processing unit 52, and outputs it to the operation calculation processing unit 51.

  When the nozzle contact detection control unit 85 receives a “nozzle contact abnormality” signal that senses contact between the workpiece and the welding torch 11 from a nozzle contact detection unit (not shown), the abnormality calculation processing unit 52 reports “nozzle contact abnormality”. Send generated signal. The cause of the occurrence of the “nozzle contact abnormality” is that the welding torch 11 to which a voltage is applied from the welding power source 10 also serving as a sensing power source is connected to the work, and the sensing voltage is lowered. Further, it may be erroneously detected that the welding torch 11 is in contact with the workpiece, and this is caused by excessive adhesion of spatter or the like to the welding torch 11.

  If the arc abnormality detection control unit 86 does not receive the welding current detection signal (WCR) transmitted from the welding power source 10 within the arc abnormality setting time, the arc abnormality detection control unit 86 detects “arc abnormality” and causes the abnormality calculation processing unit 52 to detect “arc abnormality”. Transmit the generation signal. This “arc abnormality” is caused by the fact that the flow of the shielding gas is obstructed by the spatter or the like adhering to the welding torch 11, and as a result, no arc is generated at the start of welding or the arc is cut during welding. To do.

  The sensing error detection control unit 87 detects a “sensing error” if the welding start position or the groove position cannot be detected by sensing, or if the workpiece displacement is more than expected, and the abnormality calculation processing unit 52 is detected. To send a “sensing error” signal. This “sensing error” is caused by a spatter adhering to a wire tip (not shown) of the welding torch, deterioration of electrical conductivity, work assembly error, and the like.

  The input device 90 is, for example, a teaching pendant, and the operator can input the operation of each arm of the robot body 30 by the input device 90. Further, the operator can input the skip condition input setting described above, for example, “under welding” which is a skip condition when “abnormal welding welding” occurs.

  Next, the automatic welding method of the welding robot apparatus 1 of the structure mentioned above is demonstrated with reference to the flowchart shown in FIG. 2 thru | or FIG.

  As shown in FIG. 2, first, the welding abnormality (welding scanning abnormality, nozzle contact abnormality, arc abnormality, sensing error, etc.) to be skipped as described above is set in advance by the operator using the input device 90 (S110). If the desired skip condition has been set in advance, S110 can be skipped.

  Next, when a workpiece composed of a plurality of welded joints is set at a predetermined position, a teaching program for reproducing the robot body 30 is set (S120). The teaching program includes a program for performing welding to detect the workpiece position and groove position, a evacuation program after occurrence of an abnormality, a evacuation position, in addition to a program such as a welding sequence, posture, and conditions for actual welding. A nozzle cleaning program and a reverse program from the retracted position are included.

  Subsequently, when the welding operation start start operation is performed by the operator, the waiting robot main body 30 detects the first welding start position by touch sensing according to a command based on the teaching program from the motion calculation processing unit 51. Then, welding is started (S130). The robot body 30 sequentially performs touch sensing on other weld joints, detects the welding start position, and performs welding.

  When welding is started in S130, the welding abnormality detection control unit 83 outputs the abnormality to the abnormality calculation processing unit 52 when detecting an abnormality occurring in the welded part (S140). Here, the abnormality in the welded portion refers to the above-mentioned “welding copying abnormality”, “nozzle contact abnormality”, “arc abnormality”, and “sensing error”, and each control unit of the welding abnormality detection control unit 83 has these abnormalities. If any of the above is detected, the abnormality calculation processing unit 52 is notified that an abnormality has been detected.

  If no abnormality is detected in S140 (S140: No), the operation calculation processing unit 51 continues welding the workpiece until the end of welding. When the motion calculation processing unit 51 determines that the welding work is finished based on the teaching program (S150: Yes), the robot body 30 finishes the welding work by a welding end command from the motion calculation processing unit 51. Further, the operation calculation processing unit 51 turns off the welding power source 10 via the welding power source control unit 81 and ends the welding operation (S160).

  When a welding abnormality is detected in S140 (S140: Yes), the abnormality calculation processing unit 52 determines whether the abnormality received from the welding abnormality detection control unit 83 matches any one of the skip conditions ( S170).

  If it is determined in S170 that the detected abnormality matches the skip condition (S170: Yes), a welding abnormality process is executed (S180). In S180, the welding of the welded joint where the abnormality has occurred is interrupted, the robot body 30 is retracted, the nozzle of the welding torch 11 is cleaned, and the next welded joint is welded. Details of S180 will be described later.

  In S180, the welding abnormality process is executed. Subsequently, in S190, when the operation calculation processing unit 51 determines that all welding operations are completed (S190: Yes), a welding end command from the operation calculation processing unit 51 is performed. Thus, the robot body 30 ends the welding operation, the welding power source 10 turns off the power, and ends the welding operation (S160).

  If the operation calculation processing unit 51 determines in S190 that the welding work has not been completed (S190: No), the process returns to S130.

  In S170, when the abnormality calculation processing unit 52 determines that the detected abnormality does not match the skip condition (S170: No), the abnormality calculation processing unit 52 outputs a reproduction operation interruption command to the operation calculation processing unit 51. . Then, the operation calculation processing unit 51 interrupts the welding operation (S200).

  Next, an inspection of the welding robot apparatus 1 is performed by an operator, and it is determined whether re-welding is possible based on the interrupted teaching program. At this time, if it is determined that re-welding is not possible (S210: No), the motion calculation processing unit 51 ends the welding operation of the robot body 30, the power supply of the welding power source 10 is turned off, and the welding operation is performed. The process ends (S160).

  In S210, when the worker determines that re-welding is possible based on the interrupted teaching program, the worker sets an instruction program for performing appropriate repairs on the welding robot apparatus 1 and the welding interrupted point and restarting. Then, an instruction that re-welding is possible is input to the input device 90. When there is an instruction that re-welding is possible (S210: Yes), the operation calculation processing unit 51 returns the processing to S130 and resumes the welding operation.

  Next, the welding abnormality process of S180 will be described with reference to FIG. In S170, when the abnormality calculation processing unit 52 determines that the detected abnormality matches the skip condition, the robot body 30 interrupts the welding operation according to the welding interruption command from the operation calculation processing unit 51, and the welding power source 10 The power is turned off and the welding operation is interrupted (S181).

  Subsequently, the motion calculation processing unit 51 detects data on the welded joint in which the welding operation is interrupted, the welding path in which welding is interrupted in this welded joint, and the welding interrupt position, and the data on the path of the welding path is welded. Received from the copying abnormality detection control unit 84. And the operation | movement calculation process part 51 transmits these as welding interruption data, and memorize | stores it in the welding interruption data storage part 63 (S182).

  Next, the motion calculation processing unit 51 retracts the robot main body 30 according to the retract teaching program stored in the teaching program storage unit 61 (S183).

  Subsequently, the motion calculation processing unit 51 operates the robot main body 30 at the retracted position, and in response to a command based on the nozzle cleaning program stored in the teaching program storage unit 61, the welding torch 11 is connected to the nozzle cleaning device 20 (not shown). Position at the cleaning position. Then, the operation calculation processing unit 51 issues a command to the nozzle cleaning device control unit 82, and removes spatter and the like adhering in the nozzle of the welding torch 11 (S184).

  Next, the motion calculation processing unit 51 returns the robot body 30 from the nozzle cleaning position to the retracted position by a command based on the retrograde program stored in the teaching program storage unit 61 (S185).

  Subsequently, the motion calculation processing unit 51 skips the welded joint in which the welding abnormality has occurred and sets the next welded joint (the welded joint that was scheduled to be welded next) as a welding location (S186). As described above, the operation calculation processing unit 51 executes the welding abnormality process (S180), and advances the process to S190.

  When the welding process shown in FIGS. 2 and 3 is executed and the welded joint is skipped, the welding operation of the workpiece is completed in a state where the welding is interrupted in the middle of the welded joint in which the welding abnormality is detected. In the welded joint where the welding is interrupted, repair work by the operator is subsequently performed. This repair operation removes craters and the like generated at the end of the weld bead by visual inspection of the operator so that no welding defect occurs even if re-welding is performed from the welding interruption position (end of the weld bead). . Thus, after performing the repair operation | work of the welded joint which abnormality occurred, the re-welding process shown in FIG. 4 is performed.

  As shown in FIG. 4, first, the re-execution calculation processing unit 53 reads the welding interruption data stored in the welding interruption data storage unit 63 (S310).

  Subsequently, the re-execution calculation processing unit 53 sets a teaching program for executing the re-welding process from the welding interruption data read in S310 and outputs it to the operation calculation processing unit 51 (S320). For example, the end of the weld bead where the welding is interrupted is specified from the welding interrupt data, and the teaching program is executed from the end of the weld bead.

  Next, the motion calculation processing unit 51 controls the welding power source 10 and the robot body 30 based on the teaching program set in S320, and the robot body 30 detects the end of the weld bead where the welding is interrupted by touch sensing. Then, welding is started (S330).

  The subsequent steps S330 to S410 shown in FIG. 4 are the same as the steps S130 to S210 shown in FIG.

  As described above, the welding robot apparatus and the automatic welding method according to the embodiments of the present invention include a welded joint in which a welding abnormality is detected and the welding operation is interrupted, a welding path in which welding is interrupted in this welded joint, and a welding interruption. Based on the position and the trajectory of the interrupted welding path, the end of the interrupted weld bead can be specified, and rewelding can be automatically started from the end of the weld bead. Further, even when there are a plurality of joints where welding is interrupted, re-welding can be performed together. This means that when performing multi-layer welding, particularly when assembling a large member such as a steel frame, the efficiency of the welding operation can be improved and a good weld bead can be formed.

  Further, when a welding abnormality is detected, the welding operation is interrupted, the nozzle of the welding torch is cleaned, and welding is resumed. For this reason, it is possible to minimize the recurrence of welding abnormalities caused by spatters or the like adhering to the nozzle of the welding torch. Thereby, repair work amount, such as gouging, can be reduced and work efficiency can be improved.

  In the above-described embodiment, the nozzle cleaning device that cleans the nozzle of the welding torch has been described. However, a nozzle cleaning device that removes the used nozzle from the welding torch and replaces it with a new or cleaned nozzle may be used.

  In the above-described embodiment, the operator teaches the teaching program, skip conditions, etc. of each workpiece by the input device 90. Instead of this input device 90, offline teaching using a personal computer such as a computer separately. The form using an apparatus may be sufficient.

It is a control block diagram of a welding robot apparatus and an automatic welding method according to an embodiment of the present invention. It is a flowchart figure explaining a welding robot apparatus and an automatic welding method. It is the flowchart figure which showed the process when welding abnormality generate | occur | produced. It is the flowchart figure which showed the re-welding process of the welding abnormal part.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Welding robot apparatus 10 Welding power supply 11 Welding torch 20 Nozzle cleaning apparatus 30 Robot main body 40 Welding robot control apparatus 51 Operation calculation process part 52 Abnormal calculation process part 53 Re-execution calculation process part 60 Memory | storage device 70 Robot main body control apparatus 80 External control apparatus 84 Welding profile abnormality detection control unit 85 Nozzle contact detection control unit 86 Arc abnormality detection control unit 87 Sensing error detection control unit

Claims (6)

A welding robot apparatus having a welding torch at the tip of an arm and performing welding by freely moving the arm with respect to a workpiece to be welded,
Welding abnormality detection means for detecting a welding abnormality occurring during welding of the workpiece;
Welding abnormality determining means for determining whether or not the welding abnormality detected by the welding abnormality detecting means is a predetermined abnormality capable of specifying a factor causing the welding abnormality;
When the welding abnormality is detected, welding interruption means for interrupting the welding operation;
Welding data storage means for storing welding interruption data which is data relating to the interrupted welding;
Welding interruption position specifying means for specifying the end of the interrupted weld bead from the welding interruption data stored in the welding data storage means,
A welding robot apparatus, wherein re-welding is performed from the end of the welding bead specified by the welding interruption position specifying means.   2. The apparatus according to claim 1, further comprising a nozzle cleaning device that removes deposits attached to the nozzles of the welding torch when the welding abnormality determination unit determines that the welding abnormality is a predetermined abnormality. The welding robot apparatus as described.   The welding interruption data is data relating to a welding incomplete joint in which a welding abnormality is detected, a welding path in which welding is interrupted in the welding incomplete joint, an end position of the welding path, and a locus of the welding path. The welding robot apparatus according to claim 1 or 2.   An automatic welding method in which a welding torch is provided at the tip of an arm, and a plurality of joints are welded by freely moving the arm with respect to a work to be welded. Welding is interrupted, welding interruption data that is data relating to the interrupted welding is stored, and a series of welding operations in which welding is started from the next joint by skipping the joint in which the welding abnormality is detected are performed until all the joints are performed. If there is a welding abnormality detected repeatedly, after repair of the welding abnormal part is performed by the operator, the position of the end of the welding bead is specified for each joint where welding is interrupted from the stored welding interruption data, and the welding bead An automatic welding method characterized by performing re-welding from the end.   When the welding abnormality is detected and the welding is interrupted, it is determined whether the welding abnormality is a predetermined abnormality that can identify a factor causing the welding abnormality, and when the welding abnormality is determined to be a predetermined abnormality, The automatic welding method according to claim 4, wherein deposits attached to the nozzle of the welding torch are removed.   The welding interruption data is data relating to a welding incomplete joint in which a welding abnormality is detected, a welding path in which welding is interrupted in the welding incomplete joint, an end position of the welding path, and a locus of the welding path. The automatic welding method according to claim 4 or 5.

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