JP2010253538A - Welding method and welding equipment - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To specify an occurrence and a type of welding failure properly and to perform corrective welding properly according to the type. <P>SOLUTION: The welding equipment performs the steps of: welding automatically a work W by moving a welding torch 4 with a welding robot 3; monitoring the welding condition; and applying corrective welding automatically on a failed welded portion after completion of the welding cycle, when the occurrence of the welding failure is detected. The welding equipment includes a welding power source 7 and an encoder 13 which collect a plurality of welding factor data in real time related to motion of a welding torch 4 for monitoring the welding condition (involving at least three factors among welding current, welding voltage, frequency of short circuit, feeding speed of welding wire, and supplying load of welding wire). The equipment also includes a jig control device 5 and a robot control device 6, which evaluate abnormalities of welding factor data collected to detect an occurrence of welding failure, based on combination of absence and presence of abnormalities of the welding factor data, judge the occurrence of the welding failure, specify one from a plurality of the welding failure modes, and control the welding torch 4 according to a welding failure mode judged for corrective welding. <P>COPYRIGHT: (C)2011,JPO&amp;INPIT

Description

  The present invention relates to a welding method and a welding apparatus that automatically perform work welding while automatically welding workpieces.

  Conventionally, as this type of technology, for example, in Patent Document 1 below, welding to a workpiece is automatically performed by moving a welding torch by a welding robot, and a defective portion is automatically detected by detecting the occurrence of welding failure. A welding method and a welding apparatus for carrying out correction welding in general are described. Here, as a method for detecting the occurrence of welding failure, Patent Document 1 describes comparing the values of the welding current and welding voltage to the welding torch with threshold values. Moreover, as a method for specifying the occurrence position of welding failure, Patent Document 1 describes that the occurrence position of welding failure is estimated from the time when the occurrence of welding failure is detected by the above method.

JP 2006-247663 A Japanese Patent No. 2584300 JP 2004-074264 A

  By the way, in order to properly correct and weld a defective weld location, it is necessary to accurately identify the occurrence of the poor weld and the position where the defective weld occurs. This particular reliability depends on the type and amount of data for evaluating poor welding. However, in the technique described in Patent Document 1, in order to detect the occurrence of welding failure, the welding current and the welding voltage are simply compared with threshold values as data. For this reason, the arc failure could only be assumed as the welding failure mode. Here, there are a plurality of welding failure modes such as “no weld bead”, “perforated”, “melt-through”, “undercut”, “weld bead thin”, “weld bead constriction”, and “blow hole”. Various modes can be envisaged. However, the above-described plural types of welding failure modes cannot be distinguished only from the above-described welding current and welding voltage data. In addition, since these welding failure modes cannot be distinguished from each other, it has been impossible to correct and weld the welding failure locations under appropriate conditions and methods corresponding to the respective welding failure modes. For this reason, there existed a possibility that the quality of correction welding could not be ensured. Moreover, in the technique described in Patent Document 1, in order to estimate the occurrence position of welding failure, only the time at which the occurrence of welding failure is detected is collected as data. For this reason, when a response delay has occurred in the operation of the robot, the position where the welding failure has occurred cannot be accurately estimated. Since the technique described in Patent Document 1 has the above-described problems, eventually, it was necessary to visually inspect and repair the defective welding portion in a subsequent process.

  Here, Patent Document 1 does not particularly describe how to operate the welding torch during the correction welding. As this method, a method of operating a welding torch in a wide range including a portion where correction welding is unnecessary and a method of specifying a correction welding start position by image processing are known. However, in the former method, a part for performing unnecessary correction welding is formed, and in the latter method, reliability of position accuracy by image processing is low, and it is difficult to perform appropriate correction welding. Further, both the former method and the latter method require a lot of time for the correction welding process, and the welding cycle time tends to be prolonged.

  The present invention has been made in view of the above circumstances, and a first object of the invention is to appropriately specify the occurrence and type of welding failure and to properly perform corrective welding according to the type of welding failure. An object of the present invention is to provide a welding method and a welding apparatus. In addition to the first object, a second object of the present invention is to provide a welding method and a welding apparatus capable of accurately identifying the occurrence position of a welding failure and accurately correcting and welding a welding failure location. It is in.

  In order to achieve the first object, according to the first aspect of the present invention, the workpiece is automatically welded while supplying the welding wire by moving the welding torch by the welding robot, and the welding condition is changed while welding. Monitoring and detecting the occurrence of welding defects, after a series of welding cycles have been completed, if possible, a welding method that automatically corrects and welds defective welds, and monitors the welding status Therefore, a plurality of welding factor data related to the operation of the welding torch is collected in real time during welding, and the welding factor is at least three of the welding current, the welding voltage, the number of short circuits, the welding wire supply speed, and the welding wire supply load. In order to detect the occurrence of welding defects, it is possible to determine whether there is an abnormality in the collected welding factor data and And occurrence of defects, to determine one of a plurality of weld failure modes contemplated, then, in order to correct welding, the purpose to control the welding torch in accordance with the determined defective welding mode.

  According to the configuration of the above invention, in order to monitor the welding situation, welding factor data relating to at least three welding factors among welding current, welding voltage, number of short circuits, welding wire supply speed, and welding wire supply load during welding is monitored. Are collected in real time. Then, in order to detect the occurrence of welding defects, abnormalities in the collected plurality of welding factor data are determined, and the occurrence of welding defects is determined from the combination of the presence or absence of abnormalities in the plurality of welding factor data, and a plurality of assumed weldings. One of the failure modes is properly determined. Thereafter, in order to perform correction welding, the welding torch is controlled according to the determined welding failure mode. Thereby, correction welding is performed according to the state of poor welding.

  In order to achieve the first object, in the invention described in claim 2, in the invention described in claim 1, in order to monitor the welding situation, the outer shape of the welded portion is further inspected, and the welding failure mode is set. In order to make a judgment, one of a plurality of welding failure modes assumed from the combination of the presence or absence of abnormality of a plurality of collected welding factor data is estimated, and the estimated result is compared with the inspection result of the outer shape of the welded portion. The purpose is to confirm.

  According to the configuration of the invention described above, in addition to the operation of the invention described in claim 1, in order to monitor the welding situation during welding, the outer shape of the welded portion is further inspected. In addition, in order to determine the welding failure mode, one of a plurality of welding failure modes assumed from the combination of the presence or absence of abnormality of the plurality of welding factor data collected is properly estimated, and the estimation result is the outer shape of the welded portion. Confirmed against the inspection results. Thereby, one of the plurality of welding failure modes is more appropriately determined.

  In order to achieve the second object, the invention according to claim 3 is the invention according to claim 1 or 2, wherein position data relating to the posture of the welding robot is collected in real time when the workpiece is welded. When the occurrence of a welding failure is determined, the position where the welding failure is detected is determined by the position data collected at that time, and when the correction welding is performed, the welding torch is moved to the position where the welding failure occurs. The purpose is to control the welding robot based on the position data relating to the generated position.

  According to the configuration of the above invention, in addition to the operation of the invention described in claim 1 or 2, position data relating to the posture of the welding robot is collected in real time when the workpiece is welded. When it is determined that a welding failure has occurred, the position at which the welding failure is detected is specified by the position data collected at that time. Thereafter, when performing correction welding, the welding robot is controlled based on position data relating to the occurrence position specified in order to move the welding torch to the occurrence position of the welding failure. As a result, the welding robot is restored to the posture corresponding to the position where the welding failure occurs, and the welding torch is accurately returned to the welding failure location.

  In order to achieve the first object, according to the invention described in claim 4, the welding torch is moved by the welding robot to automatically weld the workpiece while supplying the welding wire, and the welding state is being improved while welding. Monitoring and detecting the occurrence of welding defects, after a series of welding cycles are completed, if possible, a welding device that automatically corrects and welds defective welds, and monitors the welding status Therefore, a welding factor data collecting means for collecting, in real time, a plurality of welding factor data related to the operation of the welding torch during welding, the welding factor includes welding current, welding voltage, number of short circuits, welding wire supply speed, and welding wire supply In order to detect at least three of the loads and the occurrence of welding defects, anomalies in the collected plurality of welding factor data are determined, and a plurality of welding factor data are also detected. Welding failure judging means for judging the occurrence of welding failure and one of a plurality of assumed welding failure modes from the combination of presence or absence of abnormalities, and modified welding control for controlling the welding torch according to the judged welding failure mode The purpose is to provide a means.

  According to the configuration of the above invention, in order to monitor the welding situation, welding factor data relating to at least three welding factors among welding current, welding voltage, number of short circuits, welding wire supply speed, and welding wire supply load during welding is monitored. Are collected in real time by the welding factor data collection means. Then, in order to detect the occurrence of welding failure, the welding failure determination means determines the abnormality of the collected plurality of welding factor data, the occurrence of welding failure from the combination of the presence or absence of abnormality of the plurality of welding factor data, One of a plurality of possible welding failure modes is appropriately determined. Thereafter, in order to perform correction welding, the welding torch is controlled by the correction welding control means in accordance with the determined welding failure mode. Thereby, correction welding is performed according to the state of poor welding.

  In order to achieve the first object, a fifth aspect of the present invention is the welding outer shape inspection means for inspecting the outer shape of a welded place in order to monitor the welding situation in the invention of the fourth aspect. The welding failure judging means estimates one of a plurality of welding failure modes assumed from a combination of presence / absence of abnormality of a plurality of collected welding factor data, and inspects the outer shape of the welded portion with the estimated result. The purpose is to identify the welding failure mode by checking against the result.

  According to the configuration of the above invention, in addition to the operation of the invention according to claim 4, in order to monitor the welding status during welding, the outer shape of the welded portion is further inspected by the welding outer shape inspection means. Further, when determining the welding failure mode, the welding failure determination means appropriately estimates one of the plurality of welding failure modes assumed from the combination of the presence or absence of abnormality of the plurality of collected welding factor data, and the estimation The result is checked against the inspection result of the outer shape of the welded part. Thereby, one of the plurality of welding failure modes is more appropriately determined.

  In order to achieve the second object, according to a sixth aspect of the invention, in the invention of the fourth or fifth aspect, position data relating to the posture of the welding robot is collected in real time when the workpiece is welded. And a correction welding control means, further comprising: a position data collecting means for detecting, and a welding failure position specifying means for specifying a welding failure start position based on the position data collected at the time when occurrence of a welding failure is determined. The purpose of this is to control the welding robot based on the position data relating to the occurrence position specified in order to move the welding torch to the occurrence position of defective welding when performing the correction welding.

  According to the configuration of the invention described above, in addition to the operation of the invention according to claim 4 or 5, the position data related to the posture of the welding robot is collected in real time by the position data collecting means when the workpiece is welded. When it is determined that a welding failure has occurred, the position where the welding failure has occurred is specified by the welding failure position specifying means based on the position data collected at that time. Thereafter, when corrective welding is performed, the welding robot is controlled by the corrective welding control means based on the position data relating to the occurrence position specified for moving the welding torch to the occurrence position of the defective welding. As a result, the welding robot is restored to the posture corresponding to the position where the welding failure occurs, and the welding torch is accurately returned to the welding failure location.

  According to the first aspect of the present invention, it is possible to appropriately specify the occurrence and type of welding failure, and it is possible to appropriately perform corrective welding according to the type of welding failure.

  According to the invention described in claim 2, the occurrence and type of welding failure can be more appropriately specified with respect to the effect of the invention described in claim 1, and more appropriately corrected according to the type of welding failure. Can be welded.

  According to the invention described in claim 3, in addition to the effect of the invention described in claim 1 or 2, it is possible to accurately identify the occurrence position of welding failure, and to correct and weld the welding failure location accurately. it can.

  According to invention of Claim 4, generation | occurrence | production and kind of welding failure can be specified appropriately, and corrective welding can be appropriately performed according to the kind of welding failure.

  According to the invention described in claim 5, the occurrence and type of welding failure can be more appropriately specified with respect to the effect of the invention described in claim 4, and more appropriately corrected according to the type of welding failure. Can be welded.

  According to the invention described in claim 6, in addition to the effect of the invention described in claim 4 or 5, it is possible to accurately specify the occurrence position of welding failure, and to correct and weld the welding failure location accurately. it can.

1 is a schematic configuration diagram showing a welding apparatus according to an embodiment. Similarly, the flowchart which shows the flow of the welding method. Similarly, the table | surface which shows an example of data allocation in the register for correction welding. Similarly, the table | surface which shows an example of the storage method of the robot position data at the time of welding defect generation | occurrence | production. Similarly, the graph which shows the change of the welding voltage which is one of the welding factors. Similarly, the graph which shows the change of the welding current which is one of the welding factors. Similarly, the graph which shows the change of the wire supply speed which is one of the welding factors. Similarly, the graph which shows the change of the wire supply load which is one of the welding factors. Similarly, the graph which shows the change of the frequency | count of the short circuit which is one of the welding factors. Similarly, the perspective view which shows the picked-up image with the camera of a poor welding location. Similarly, a table showing the relationship between various “welding failure modes” and the corresponding “welding current” and “welding voltage” “conditional ratio of original welding conditions”. Similarly, the conceptual diagram which shows the teaching point which concerns on the movement of a welding torch in the welding locus at the time of normal welding, a welding defect generation position, and a welding defect end position. Similarly, the conceptual diagram which shows the 1st case which concerns on the correction welding range in the relationship of FIG. Similarly, the conceptual diagram which shows the 2nd case which concerns on the correction welding range in the relationship of FIG. Similarly, the conceptual diagram which shows the 3rd case which concerns on the correction welding range in the relationship of FIG.

  DETAILED DESCRIPTION Hereinafter, an embodiment embodying a welding method and a welding apparatus of the present invention will be described in detail with reference to the drawings.

  In FIG. 1, the welding apparatus of this embodiment is shown with a schematic block diagram. This welding apparatus monitors the welding situation in real time while automatically welding the workpiece W. And when the occurrence of a welding failure is detected, the location of the welding failure and the welding failure mode are memorized, and after completing a series of welding cycles, the welding failure point is checked and corrected if possible. It is configured to perform welding automatically.

  This welding apparatus includes a jig 1 that movably supports a workpiece W, a welding robot 3 having an articulated arm 2, a welding torch 4 that is attached to the tip of the arm 2 and welds the workpiece W, and a jig. A jig control device 5 for controlling the tool 1, a robot control device 6 for controlling the welding robot 3, a welding power source device 7 for supplying power to the welding torch 4, and welding by the welding torch 4 A camera 8 for photographing the outer shape and a welding outer shape inspection device 9 for inspecting the outer shape of welding based on the photographing data of the camera 8 are provided. The inspection result of the welding outline inspection device 9 is sent to the jig control device 5. The jig control device 5 includes a correction welding register 10 for storing various data for correction welding. Predetermined data is exchanged between the robot control device 6, the jig control device 5 and the welding power supply device 7.

  Each of the jig control device 5, the robot control device 6, and the welding contour inspection device 9 includes a central processing unit (CPU) and a memory. The CPU executes predetermined control based on a program stored in the memory. In this embodiment, the jig control device 5 and the robot control device 6 correspond to a welding failure determination unit, a corrected welding control unit, and a welding failure position specifying unit of the present invention. The camera 8 and the welding contour inspection device 9 correspond to the welding contour inspection means of the present invention.

  From the welding torch 4 attached to the tip of the arm 2, a welding wire 11 is provided at a welding location so as to be supplied. In order to supply the welding wire 11 to the welding torch 4, the arm 2 is provided with a welding wire feeder 12. The welding wire feeder 12 is configured with a motor as a drive source, and includes an encoder 13 for detecting a wire feeding speed. The value detected by the encoder 13 is sent to the welding power source device 7. In this embodiment, the welding power source device 7 and the encoder 13 correspond to the welding factor data collection means of the present invention.

  The welding robot 3 including the arm 2 includes a plurality of (six in this case) rotating shafts, and encoders 14, 15, 16, 17, 18, 19 for detecting a coaxial rotation angle are provided on each rotating shaft. Each is provided. The detection values by these encoders 14 to 19 are sent to the robot control device 6. In this embodiment, the encoders 14 to 19 correspond to position data collection means of the present invention.

  Here, the outline | summary of the welding method performed using the above-mentioned welding apparatus is demonstrated below. When arc welding the workpiece W with the welding torch 4, the welding robot 3 operates the arm 2 in the order taught in advance. Here, during welding, the welding situation is divided into a large number of welding factors and monitored in real time, and each welding factor data is compared with a threshold value which is a predetermined judgment criterion to determine whether there is an abnormality. Determine whether it occurred. When it is determined that a welding failure has occurred, data on the position where the welding failure has occurred (position data related to the attitude of the welding robot 3) and a specific welding failure mode (not just a mode of arc break). Remember. This specific welding failure mode is one estimated from a plurality of welding failure modes classified and assumed by combining a number of welding factor data in a composite manner. Then, after a series of welding cycles are completed, the occurrence position of the welding failure is photographed by the camera 8 based on the occurrence position data stored in advance, and the photographing data is compared with the estimated welding failure mode. And it is sure whether it is a welding failure and the welding failure mode in which the correction welding is possible. Thereafter, if possible, the welding torch 4 is automatically moved by the welding robot 3 from the position where the welding failure occurs or a position before the position where the welding failure occurs in order to correct and weld the defective welding location. Here, since the welding torch 4 uses the teaching program that is normally used as it is, there is no harmful shift between the normal welding position and the position where the welding failure requiring correction welding occurs. This can be realized by jumping the process to the operation instruction instruction portion of the program after determining execution of the correction welding. In addition, in the estimation of the welding failure mode, a change in welding conditions that results in a welding failure and a welding failure mode that is expected to occur as a result are stored in advance as a map. Further, the welding conditions for correction welding are also stored in advance.

  Next, the above welding method will be described in detail with reference to FIGS. FIG. 2 is a flowchart showing the flow of the welding method. FIG. 3 is a table showing an example of data allocation in the correction welding register 10. As shown in this table, “stored data content” and “stored data format” are stored corresponding to each “address”. FIG. 4 is a table showing an example of a method for storing robot position data when welding failure occurs. This table stores “J1-axis to J6-axis robot position data” corresponding to “address”, “stored value”, and “Pn variable” in the correction welding register 10. FIG. 5 is a graph showing changes in welding voltage, which is one of the welding factors. FIG. 6 is a graph showing changes in welding current, which is one of the welding factors. FIG. 7 is a graph showing changes in the wire supply speed, which is one of the welding factors. In FIG. 8, the change of the wire supply load which is one of the welding factors is shown with a graph. In FIG. 9, the change of the frequency | count of the short circuit which is one of the welding factors is shown with a graph. FIG. 10 is a perspective view showing an image taken by the camera 8 at a poorly welded portion. FIG. 11 is a table showing the relationship between various “welding failure modes” and the corresponding “welding current” and “welding voltage” to “condition ratio of original welding conditions”.

  When welding by the welding apparatus starts, in step 100, the welding power source apparatus 7 collects a plurality of welding factor data in real time. In this embodiment, as a plurality of welding factor data, “welding current” and “welding voltage” supplied to the welding torch 4, “number of short circuits” of the welding torch 4, and the welding wire 11 supplied to the welding torch 4 are related. The values of “wire supply speed” and “wire supply resistance” can be mentioned. The “wire supply speed” and the “wire supply resistance” are obtained based on the detection value of the encoder 13. The plurality of collected welding factor data is sent from the welding power source device 7 to the robot control device 6 and collected for each continuous weld bead.

Next, in step 110, the robot controller 6 determines the occurrence of a welding failure based on the plurality of sent welding factor data. The robot controller 6 makes this determination by determining whether or not there is an abnormality in the plurality of sent welding factor data based on threshold values set in advance corresponding to various welding factors. In this embodiment, as threshold values, for example, “the upper limit value and the lower limit value of the welding current value”, “the upper limit value and the lower limit value of the welding voltage value”, “the upper limit value and the lower limit value of the number of short circuits”, “the upper limit of the wire supply speed” Value and lower limit value "and" upper limit value and lower limit value of wire supply resistance value ". When the robot control device 6 determines that each welding factor data has an abnormality based on the above-described threshold value, the robot control device 6 measures the duration of the abnormality and uses the measurement result as a correction welding register of the jig control device 5. 10 is stored. For example, when the welding current value is lower than the lower limit value and the current value (effective value) is 30% of the set value (target value), “0203000” is stored (FIG. 3). The threshold value is determined based on the condition margin of the welding location, such as “the actual waveform is ± 10% relative to the standard waveform” or “the average value is ± 10% relative to the target condition value”. In this case, as shown in FIG. 3, “corrected welding content” is specifically stored in the correction welding register 10 corresponding to the address “910000”.

  Next, in step 120, the robot control device 6 performs extraction and determination of data related to the occurrence position of the welding failure based on the plurality of welding factor data. That is, when the robot controller 6 determines that a welding failure has occurred, the robot controller 6 associates the attitude data of the welding robot 3 related to the position of the welding torch 4 at that time with the welding factor data determined in step 110. It is stored in the correction welding register 10 as a necessary portion (range) of the correction welding. In this case, as shown in FIG. 3, “robot position data when welding failure occurs” is specifically stored in the correction welding register 10 in correspondence with the address “940000”. Here, the “robot position data” corresponds to detection values of the six encoders 14 to 19 provided on the six rotation axes of the welding robot 3. Specifically, as shown in FIG. 4, numerical values related to “address”, “stored value”, and “Pn variable” are stored in the “correction welding register data” column, and the “robot position data” column. Numerical values relating to “J1 axis, J2 axis, J3 axis, J4 axis, J5 axis, J6 axis” relating to the arm 2 of the welding robot 3 are stored.

  Next, at step 130, the jig control device 5 estimates a welding failure mode based on the content of the welding failure. That is, the jig control device 5 estimates the welding failure mode from the combination of the welding factor abnormality data for each welding failure content stored in the correction welding register 10 in step 110. The jig control device 5 performs this estimation with reference to a predetermined welding failure mode map stored in advance. Here, there are seven welding failure modes: “no weld bead”, “perforated”, “melt-through”, “undercut”, “weld bead fine”, “weld bead constriction” and “blow hole”. A mode is assumed. The jig control device 5 stores the above estimation result in the correction welding register 10. In this case, as shown in FIG. 3, “welding failure mode estimation result” is specifically stored in the correction welding register 10 corresponding to the address “960000”. For example, among the changes in welding voltage, welding current, wire supply speed, wire supply load, and number of short circuits as the welding factor data shown in FIGS. 5 to 9, FIGS. 6 to 8 are surrounded by chain line circles S 1, S 2, S 3. If the welding current value is significantly lower than the threshold value I1, the wire supply speed value is significantly lower than the threshold value V1, and the wire supply load value suddenly increases, a part of the weld bead It can be estimated that “no weld bead” is missing.

  Next, in step 140, the welding contour inspection apparatus 9 inspects the appearance of the defective welding portion. That is, the inspection device 9 confirms the matching with the poor welding state based on the data captured by the camera 8. Then, the inspection device 9 sends the inspection result to the correction welding register 10 of the jig control device 5.

  Next, in step 150, the jig control device 5 determines the welding failure mode based on the estimation result of the welding failure mode and the appearance inspection result of the welding failure portion. That is, the jig control device 5 determines whether or not the estimated welding failure mode is correct by comparing the welding failure mode estimated in step 130 with the appearance inspection result of the welding failure portion inspected in step 140. Alternatively, one welding failure mode is specified from a plurality of estimated welding failure modes and determined, and the determination result is stored in the correction welding register 10. Further, the jig control device 5 determines whether or not the defective welding location is correctable or not, determines a location where the corrective welding is performed, and stores the determination result in the corrective welding register 10. For example, as shown in FIG. 10, when a part of the weld bead 21 is missing as shown in FIG. 10, the estimation result of step 130 is consistent with “no weld bead”. In this case, the welding failure mode is determined as “no weld bead”, and the determination result is stored in the correction welding register 10.

  Next, at step 160, the jig control device 5 determines a corrected welding condition for each determined welding failure mode. That is, the jig control device 5 determines a welding condition to be used for correction by referring to a pre-registered welding condition map for each welding failure mode determined in step 150, and determines the determination result. It is stored in the correction welding register 10. For example, the jig control device 5 refers to a table as shown in FIG. 11, determines the welding current and welding voltage condition ratios corresponding to various welding failure modes, and stores the determination results. In this embodiment, as shown in FIG. 11, a combination of “welding current” and “welding voltage” corresponding to various “welding failure modes” is determined. That is, when the welding failure mode is “no weld bead”, the welding current is “100%” and the welding voltage is “100%”. When the welding failure mode is “perforated”, the welding current is “120%” and the welding voltage is “100%”. When the welding failure mode is “burn-out”, the welding current is set to “cannot be corrected” and the welding voltage is set to “cannot be corrected”. When the welding failure mode is “undercut”, the welding current is “100%” and the welding voltage is “80%”. When the welding failure mode is “weld bead thin”, the welding current is “80%” and the welding voltage is “80%”. When the welding failure mode is “weld bead constriction”, the welding current is set to “90%” and the welding voltage is set to “80%”. When the welding failure mode is “blowhole”, the welding current is “80%” and the welding voltage is “100%”. For example, as shown in FIG. 3, “correction welding condition number determined to be correction welding possible / impossible” is specifically stored in the correction welding register 10 in correspondence with the address “970000”. .

  Next, at step 170, the jig control device 5 instructs a program for sequentially correcting the defective welding locations. That is, the jig control device 5 instructs the robot control device 6 about the modified welding condition stored in step 160 for each location where the modified welding stored in step 150 is necessary.

  Next, in step 180, the robot control device 6 moves the welding torch 4 to a welding failure location. In other words, the robot control device 6 controls the welding robot 3 based on the position data of the welding robot 3 related to the welding failure occurrence position determined in step 120, so that the welding torch 4 needs to be subjected to the correct welding. Move.

  Next, in step 190, the robot control device 6 operates the welding torch 4 based on the corrected welding condition to correct and weld the defective welding portion. That is, the robot control device 6 operates the welding robot 3 on the basis of the corrected welding conditions instructed in Step 170 and operates the welding torch 4 via the welding power source device 7 to re-weld the welding failure portion. . In this embodiment, for example, a second case moving method described later is employed.

  Here, the moving method of the welding torch 4 when executing the correction welding will be described below with reference to FIGS. FIG. 12 is a conceptual diagram showing teaching points 23, 24, and 25, a welding failure occurrence position 26, and a welding failure end position 27 related to the movement of the welding torch 4 in the welding locus 22 at the time of normal welding indicated by a broken line. FIG. 13 is a conceptual diagram showing a first case related to the modified welding range 28 in the relationship of FIG. In FIG. 14, the 2nd case which concerns on the correction welding range 28 in the relationship of FIG. 12 is shown with a conceptual diagram. FIG. 15 is a conceptual diagram showing a third case related to the modified welding range 29 in the relationship of FIG.

  As shown in FIG. 13, the first case is a modified welding range 28 from the welding failure occurrence position 26 to the welding failure end position 27. At this time, the welding torch 4 is moved to the welding failure occurrence position 26 without performing correction welding, that is, “idle running” 30 is performed, and the correction welding range 28 between the welding failure occurrence position 26 and the welding failure end position 27 is performed. And moving while correcting welding, and the idle running 30 is performed again from the welding failure end position 27.

  As shown in FIG. 14, in the second case, the welding torch 4 is moved between two teaching points 23 and 25 including a welding failure occurrence position 26 and a welding failure end position 27, and welding within that range is performed. The range from the defect occurrence position 26 to the welding defect end position 27 is the corrected welding range 28. At this time, the welding torch 4 is idled 30 to the welding failure occurrence position 26 via one teaching point 23, and in the corrected welding range 28 from the welding failure occurrence position 26 to the welding failure end position 27. It is moved while making correction welding, and idle running 30 is performed from the welding failure end position 27 via the other teaching point 25.

  As shown in FIG. 15, in the third case, the welding torch 4 is moved between two teaching points 23 and 25 including a welding failure occurrence position 26 and a welding failure end position 27, and 2 within the range. The range between the two teaching points 23 and 25 is the modified welding range 29. At this time, the welding torch 4 runs idly 30 to one teaching point 23 and is moved while performing correction welding in the correction welding range 29 between one teaching point 23 and the other teaching point 25, and the other The idle run 30 is performed again from the teaching point 25.

  Returning to the flowchart of FIG. 2, next, in step 200, the robot control device 6 confirms whether or not the correction welding of all the defective welding portions has been normally completed. In other words, the robot controller 6 collects welding factor data in real time in the same manner as in step 100 for each welding defect occurrence position that requires correction welding, and based on the welding factor data collected in the same manner as in step 110, Judgment is made.

  Thereafter, in step 210, the welding contour inspection apparatus 9 confirms the appearance of the welded defective portion that has been corrected and welded. That is, the welding outline inspection device 9 confirms whether or not the corrected welding defect portion is normally welded by the appearance inspection similar to step 140 in accordance with the confirmation in step 200, and the result is used for the correction welding. Store in the register 10. For example, as shown in FIG. 3, “normal / abnormal outer shape inspection result of corrected welding location” is stored in the correction welding register 10 in correspondence with the address “990000”. Thus, a series of correction welding is once complete | finished.

  According to the welding method and the welding apparatus of this embodiment described above, the work W is automatically welded while the welding torch 4 is moved by the welding robot 3 and the welding wire 11 is supplied, and the welding situation is being performed during the welding. To monitor. When the occurrence of welding failure is detected, after a series of welding cycles are completed, the welding torch 4 is moved by the welding robot 3 and the welding wire 11 is supplied automatically if possible, while the welding wire 11 is supplied. Fix and weld.

  Here, in order to monitor the welding situation, six welding factor data relating to the operation of the welding torch 4 is collected in real time by the welding power source device 7 during welding. That is, the welding factor data relating to all the welding factors of the welding current, the welding voltage, the number of short circuits, the welding wire supply speed, and the welding wire supply load are collected in real time. And in order to detect generation | occurrence | production of a welding defect, the jig | tool control apparatus 5 and the welding robot control apparatus 6 judge the abnormality of the collected six welding factor data, respectively, and the presence or absence of abnormality of six welding factor data is detected. The occurrence of poor welding from the combination and one of the seven possible welding failure modes are appropriately determined. Thereafter, in order to perform correction welding, the welding torch 4 is controlled by the jig control device 5 and the welding robot control device 6 in accordance with the determined welding failure mode. Thereby, correction welding is performed according to the state of poor welding. As a result, the occurrence and type of welding failure can be specified appropriately, and corrective welding can be appropriately performed according to the specified type of welding failure.

  Moreover, in this embodiment, in order to monitor the welding situation during welding, the outer shape of the welding location is further inspected by the camera 8 and the welding outer shape inspection device 9. In addition, in order to determine the welding failure mode, one of the seven welding failure modes assumed from the combination of the presence or absence of abnormality of the six welding factor data collected by the jig control device 5 and the robot control device 6 is appropriate. The estimated result is verified against the inspection result of the outer shape of the welded portion. Thereby, one of the seven welding failure modes is determined more appropriately. In this sense, the occurrence and type of welding failure can be specified more appropriately, and corrective welding can be performed more appropriately according to the specified type of welding failure.

  In particular, when compared with the prior art described in Patent Document 1, this prior art simply detected the occurrence of welding failure by simply comparing the welding current and welding voltage with a threshold value as data. In this embodiment, The occurrence of welding failure and the welding failure mode are determined from the combination of the presence or absence of abnormality in the six welding factor data. For this reason, in this embodiment, for each weld bead, it is possible to capture welding defects as a group of ranges, and assume the occurrence of one welding failure mode by assuming seven welding failure modes. It can be judged appropriately.

  Furthermore, in this embodiment, when welding the workpiece W, position data related to the posture of the welding robot 3 is collected by the jig control device 5 and the robot control device 6 in real time. When it is determined that a welding failure has occurred, the position where the welding failure has occurred is specified by the jig control device 5 and the robot control device 6 based on the position data collected at that time. Thereafter, when performing correction welding, the welding robot 3 is controlled by the jig control device 5 and the robot control device 6 based on the position data related to the generation position specified for moving the welding torch 4 to the position where the welding failure occurs. Is done. Thereby, the welding robot 3 is restored to the posture corresponding to the position where the welding failure occurs, and the welding torch 4 is accurately returned to the welding failure location. As a result, it is possible to accurately specify the position where the welding failure occurs, and to correct and weld the welding failure location accurately.

  In particular, as compared with the prior art described in Patent Document 1, this prior art has estimated the occurrence position of welding failure based on the time data when the occurrence of welding failure is detected. In this embodiment, the welding robot The position where the welding failure occurs is specified by the position data related to the posture of 3. For this reason, in this embodiment, the occurrence position of the welding failure can be specified with high accuracy without being affected by the response delay of the operation of the welding robot 3. Further, it is possible to accurately specify a predetermined range including a plurality of generation positions.

  Further, in this embodiment, the teaching program that is normally used is used as it is, and the occurrence position of a welding defect that requires correction welding is stored in the program. For this reason, correction welding can also be performed based on the same teaching program. In this sense, the interference between the welding torch 4 and the workpiece W or the jig 1 can be prevented before the welding torch 4 is moved to a position where a welding failure requiring correction welding occurs. Moreover, the welding torch 4 can be moved without shifting from the position where the welding failure occurs.

  In addition, this invention is not limited to the said embodiment, In the range which does not deviate from the meaning of invention, it can implement as follows.

  (1) In the above-described embodiment, all of the welding current, welding voltage, number of short circuits, welding wire supply speed, and welding wire supply load are used as welding factors, and the occurrence of welding failure based on the six welding factor data relating to these welding factors. Judgment of poor welding mode. On the other hand, the welding current, welding voltage, number of short circuits, welding wire supply speed, and welding wire supply load are set to three, four, or five welding factors, and the welding failure is based on the welding factor data relating to those welding factors. Occurrence and welding failure mode may be determined. In this case, the assumed welding failure modes are fewer than the seven in this embodiment.

  (2) In the above embodiment, when determining the welding failure mode, one welding failure mode estimated from a plurality of welding failure modes is checked against the inspection result of the outer shape of the welded portion. It is also conceivable to omit the verification check with the outer shape inspection result of the welded portion.

  (3) In the above embodiment, the occurrence position of the welding failure is specified based on the position data related to the attitude of the welding robot. However, only the method for specifying the occurrence position of the welding failure is the same as in the prior art. It may be estimated based on time data when the occurrence of a defect is detected or specified by other methods.

  The present invention can be used, for example, for arc welding of a vehicle body in an automobile production line.

2 Arm 3 Welding robot 4 Welding torch 5 Jig control device (welding failure judgment means, correction welding control means, welding failure position specifying means)
6 Robot controller (welding failure judgment means, correction welding control means, welding failure position specifying means)
7 Welding power supply (welding factor data collecting means)
8 Camera (welding outline inspection means)
9 Welding outline inspection device (welding outline inspection means)
DESCRIPTION OF SYMBOLS 10 Register for correction welding 11 Welding wire 12 Welding wire supply machine 13 Encoder (welding factor data collection means)
14 Encoder (Position data collection means)
15 Encoder (Position data collection means)
16 Encoder (Position data collection means)
17 Encoder (Position data collection means)
18 Encoder (Position data collection means)
19 Encoder (Position data collection means)
26 Welding failure occurrence position 27 Welding failure end position 28 Corrected welding range 29 Corrected welding range W Workpiece

Claims (6)

When the welding torch is moved by the welding robot and the welding wire is supplied, the workpiece is automatically welded, the welding status is monitored while welding, and when a defective weld is detected, a series of welding cycles is completed. Then, if possible, a welding method that automatically corrects and welds defective welds,
In order to monitor the welding status, a plurality of welding factor data relating to the operation of the welding torch during the welding is collected in real time,
The welding factor includes at least three of a welding current, a welding voltage, the number of short circuits, a welding wire supply speed, and a welding wire supply load,
In order to detect the occurrence of the welding defect, the abnormality of the collected plurality of welding factor data is determined, and the occurrence of a welding defect is assumed from the combination of the presence or absence of the abnormality of the plurality of welding factor data. One of the welding failure modes of
Thereafter, in order to perform the correction welding, the welding torch is controlled according to the determined welding failure mode. In order to monitor the welding situation, further inspect the outer shape of the welding location,
In order to determine the welding failure mode, one of a plurality of welding failure modes assumed from a combination of presence / absence of abnormality of the plurality of collected welding factor data is estimated, and the estimation result is calculated as an outer shape of the welding location. The welding method according to claim 1, wherein the verification is performed by checking with the inspection result. Collecting position data related to the position of the welding robot in real time when welding the workpiece,
When the occurrence of the welding failure is determined, the position where the welding failure is started is specified by the position data collected at that time,
2. The welding robot according to claim 1, wherein the welding robot is controlled based on position data relating to the specified generation position in order to move the welding torch to the generation position of the welding failure when performing the correction welding. 2. The welding method according to 2. When the welding torch is moved by the welding robot and the welding wire is supplied, the workpiece is automatically welded, the welding status is monitored while welding, and when a defective weld is detected, a series of welding cycles is completed. Later, if possible, a welding apparatus that automatically corrects and welds defective welds,
Welding factor data collecting means for collecting a plurality of welding factor data related to the operation of the welding torch during welding in order to monitor the welding state;
The welding factor includes at least three of a welding current, a welding voltage, the number of short circuits, a welding wire supply speed, and a welding wire supply load;
In order to detect the occurrence of the welding defect, the abnormality of the collected plurality of welding factor data is determined, and the occurrence of a welding defect is assumed from the combination of the presence or absence of the abnormality of the plurality of welding factor data. Welding failure determination means for determining one of the welding failure modes;
A welding apparatus comprising: a correction welding control means for controlling the welding torch according to the determined welding failure mode in order to perform the correction welding. In order to monitor the welding situation, further comprising a welding contour inspection means for inspecting the contour of the welding location,
The welding failure determination means estimates one of a plurality of welding failure modes assumed from a combination of the presence or absence of abnormality of the plurality of collected welding factor data, and the estimation result is an inspection result of the outer shape of the welding location. The welding apparatus according to claim 4, wherein the welding failure mode is specified by checking and checking. Position data collection means for collecting in real time position data related to the posture of the welding robot when welding the workpiece;
A welding failure position specifying means for specifying a welding failure start position based on position data collected at that time when occurrence of the welding failure is determined;
The correction welding control means controls a welding robot based on position data relating to the specified generation position in order to move the welding torch to the generation position of the welding failure when performing the correction welding. The welding apparatus according to claim 4 or 5.

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