JP6659431B2 - Consumables monitoring device - Google Patents

Description

  The present invention relates to a consumable supply monitoring device that outputs information on replacement of consumables in a welding torch of a welding robot.

  Each time welding is performed, the power supply tip used for arc welding wears due to friction with a wire and deterioration due to heat generation during power supply. A worn power supply tip is one of the factors that hinder uniform welding quality, such as a change in a power supply position, a displacement of a target position of a wire, and an increase in feed resistance. For this reason, it is necessary to periodically replace the power supply chip, but there is a problem that it is difficult to grasp an appropriate replacement time. For example, if the power supply tip is replaced at a time when the welding quality is not affected, the replacement time will be too early, and the cost will increase unnecessarily. On the other hand, if the worn power feeding tip is continuously used to reduce the cost, the welding quality may be affected and welding failure may be caused.

Therefore, as a method of managing electrodes in arc welding, there is known a technique of accumulating the number of times of occurrence of arcs and the time of occurrence of arcs, which are the consumable factors of the electrodes, and replacing the electrodes when exceeding a reference amount (for example, , Patent Document 1).
Further, there is known a technique of detecting a change in a power supply position to a welding wire due to wear of a power supply tip and monitoring wear of the power supply tip by monitoring the welding current with a threshold (for example, Patent Document 2). ).

JP 2008-80400A JP 2009-61489A

However, the method described in Patent Literature 1 requires a skill and experience in welding to set the threshold values of each of the power supply chip wear factors such as current and voltage, and there is a problem that the grounds for determining whether the threshold values are appropriate are poor. there were.
According to the method described in Patent Literature 2, it is possible to grasp the degree of wear of the power supply tip to a certain extent by detecting a change in the power supply position of the power supply tip from a change in the current value and the voltage value during welding. However, the current value and the voltage value at the time of welding vary temporarily due to factors other than the wear of the power supply tip, for example, accuracy errors of the work, and thus may temporarily vary. For this reason, there is a problem in that even if the power supply tip that has not been worn is used, it is erroneously detected as worn.

In order to solve the above problems, according to the present invention,
In the consumables monitoring device that monitors the replacement time of the consumables of the arc welding device,
A consumable factor measuring unit for measuring a value of a consumable factor of the consumable,
A wear degree calculation unit that calculates the wear degree of the consumable based on the measured value of the wear factor,
An exchange time calculation unit that estimates a period until the accumulated value of the consumption degree reaches a predetermined threshold, and calculates an exchange time of the consumable.
An exchange time output section for outputting the calculated exchange time to the outside,
Equipped with a,
The replacement time calculation unit estimates a period until the threshold value is reached, based on the degree of wear recorded in the past.
With this configuration, the future trend of wear is calculated from the past trend of wear.
can do. This allows the consumables to be replaced in a timely manner

  ADVANTAGE OF THE INVENTION According to the consumables monitoring apparatus by this invention, the replacement period of the consumables in an arc welding apparatus can be grasped appropriately. As a result, it is possible to avoid an increase in cost due to being too early and a problem of poor welding due to being too late at the time of replacing the consumables.

FIG. 1 shows a configuration of a welding robot system having a consumable supply monitoring device according to a first embodiment of the present invention. FIG. 7 is a view for explaining consumption of a power supply chip in the embodiment. FIG. 7 is a diagram illustrating an example of calculation of a degree of wear in the embodiment. FIG. 7 is a diagram illustrating an example of a change transition calculation of a degree of wear using a regression line in the embodiment. FIG. 7 is a diagram showing an example of calculating a change transition of a degree of wear based on a straight line curve in the embodiment. FIG. 4 is a diagram for explaining processing of a consumable factor measuring unit 21 in the consumables monitoring device 2 according to the embodiment. FIG. 4 is a diagram for explaining processing of a consumption degree calculation unit 22 in the consumable supply monitoring device 2 according to the embodiment. FIG. 4 is a diagram for describing processing of a replacement time calculation unit 23 in the consumable supply monitoring device 2 according to the embodiment.

  Hereinafter, a consumable goods monitoring apparatus according to the present invention will be described using embodiments. Note that, in the following embodiments, components denoted by the same reference numerals are the same or equivalent, and the description thereof may not be repeated. The consumables monitoring device according to the present embodiment has different coefficients for the measured values of the current and voltage during welding, the wire feed amount, the number of arc occurrences, the arc occurrence time, the number of welding abnormalities, and the wire feed amount during non-welding. And monitor the consumables using the accumulated value. In the present embodiment, the consumable to be monitored is the power supply tip 27 at the tip of the welding torch 3a described later.

FIG. 1 is a diagram showing a configuration of a welding robot system according to the present embodiment. The welding robot system 101 according to the present embodiment includes a robot control device 1, a welding robot 3, a welding torch 3a, a welding machine 4, a wire feeding device 5, and an input / output terminal 6.
FIG. 2 is a cross-sectional view of the power supply tip 27 at the tip of the welding torch 3a attached to the tip of the welding robot 3. A welding wire 28 is inserted into the power supply tip 27, and the welding wire 28 and the power supply tip 27 are in contact at a power supply point 29.

The welding robot 3 is an articulated manipulator having a plurality of axes, and is driven by a motor via a speed reducer. The motor has an encoder and can detect the rotation angle of each axis. A welding torch 3a is attached to the tip of the welding robot 3, and a power supply tip 27 is attached to the tip of the welding torch 3a.
The welding wire 28 fed from the wire feeding device 5 passes through the welding torch 3a and the inside of the power supply tip 27. The welding machine 4 applies a high voltage between the welding torch 3 a and the work 8, and generates an arc between the welding wire 28 inserted through the power supply tip 27 and the work 8. Welding is performed by melting the work 8 and the fed welding wire 28 by the heat generated by the arc.

The welding machine 4 includes a power supply for applying a high voltage for welding to the welding torch 3 a and the base material 8, a wire feeding control unit for controlling the feeding of the welding wire 28 by the wire feeding device 5, and a robot control device 1. And a welding control unit for controlling a welding power source in accordance with the welding conditions transmitted from the controller. The welding control unit monitors the welding state, and outputs an arc generation signal to the wear factor measuring unit 21 while the arc is generated. Also, when a welding defect such as arc break or welding occurs, a welding defect occurrence signal is output to the wear factor measuring unit 21.
Further, the wire feeding device 5 has a wire monitoring unit 5a for monitoring a wire feeding amount. The wire monitoring unit 5a has an encoder, and can measure the speed and the amount of the fed wire.

  The input / output terminal 6 is a terminal, such as a teach pendant, used for teaching of the welding robot 3 and checking during a reproducing operation, and has an output device such as a display, an input device such as a button, and the like. . The input / output terminal 6 notifies the robot control device 1 of corresponding information and the like by an operation input from the input device. The information notified at this time is, for example, information such as the operation direction and speed at the time of manual operation of the robot, editing and storage of a work program, and the like. Further, information corresponding to the notified operation is displayed on an output device such as a display. At this time, the information output to the display or the like is, for example, information on each axis angle at the time of manual operation, or the contents of the edited work program. A signal or the like input from the input / output terminal 6 to the robot control device 1 may be input / output to the execution unit 12 or the welding control unit 14 via a path (not shown). It may be input and output to the degree calculation unit 22, the exchange time output unit 24, and the like. For example, information output from the consumables monitoring device 2 may be received, displayed on a display, or output audio. The information output from the consumables monitoring device 2 may be a replacement timing of the power supply chip 27 described later, a power supply chip replacement command, or a degree of wear.

  The robot control device 1 includes a teaching information storage unit 11, an execution unit 12, a servo control unit 13, a welding control unit 14, and a consumables monitoring device 2.

The teaching information storage unit 11 stores a moving command including each axis angle and speed in the work program, a teaching information including a welding start and a welding ending command, and wear degree related information described later. The teaching information includes a movement command as described above, and includes position information such as a rotation position of each axis motor of the welding robot 3, a rotation speed, and coordinate information indicating a tip position of the welding robot 3. I have. Further, the welding start and welding end instructions include welding information such as current and voltage command values to be notified to the welding machine 4 and welding parameter values indicating a welding control method.
The wear degree related information includes information about which wear factor is measured, a coefficient for each wear factor, a type of regression analysis method used for estimating a replacement time described later, and a wear degree threshold value. The wear degree related information may be held separately from the teaching information, or may be included in the teaching information. The teaching information and the degree of wear-related information are realized by a semiconductor memory, a magnetic disk, or the like, which is held in the teaching information storage unit or commonly used in the robot controller 1.

  The execution unit 12 generates a position command and a speed command of a rotation position for each axis motor of the welding robot 3 according to the teaching information and a signal notified from the input / output terminal 6. These commands may be output to the servo control unit 13. The execution unit 12 interprets the teaching information and the signal from the input / output terminal 6 and outputs a command such as start and end of welding to the welding control unit 14. The command includes welding parameters such as a welding current and a welding voltage, and may include parameters related to welding, such as a welding method and a control method. Further, the execution unit 12 refers to the wear degree related information at the time of a command such as the start or end of the welding, and notifies the start and end of the measurement of the wear factor to the wear factor measurement unit 21 via a path (not shown). May be.

  The servo control unit 13 receives a position command and a speed command of a rotation position for each axis motor of the welding robot 3 notified from the execution unit 12, and controls the driving of each axis motor. In addition, information such as the current position is received from the encoder of each axis motor of the welding robot 3 and feedback control is performed so that the rotation position and speed of each axis motor become the position and speed indicated by the command received from the execution unit 12. .

  The welding control unit 14 receives the welding start and end commands received from the execution unit 12 and notifies the welding machine 4 of output commands such as welding current and welding voltage.

  The consumables monitoring device 2 includes a consumable factor measuring unit 21, a consumable degree calculating unit 22, and a replacement timing output unit 24. In addition, the consumables monitoring device 2 may be built in the robot control device 1, may be communicably connected to the outside, or may be built in the welding machine 4.

Here, before describing the wear factor measuring unit 21, the wear factor will be described. The wear factor in the present invention includes at least one of a current value, a voltage value, a wire feed amount, an arc generation time, an arc generation number, a welding failure frequency and a wire supply amount during non-arc welding in arc welding. . Next, how each of these wear factors relates to wear of the power supply chip 27 will be described. First, a major cause of abrasion of the power supply tip 27 is heat generation between the power supply tip 27 and the welding wire 28 when an arc is generated. When a welding voltage is applied from the welding machine 4, a voltage is applied to the welding wire 28 at the power supply point 29 through the power supply tip 27. At this time, the contact portion 29 has a considerable resistance, and a current flows when a voltage is applied, and heat energy is generated at that time. Heat is generated between the power supply tip 27 and the welding wire 28 in this manner.
The power supply chip 27 is generally made of a metal material such as copper having high conductivity, and heat generation during power supply causes thermal deterioration or deformation. When thermal degradation occurs, the conductivity of the power supply chip 27 is generated, and the resistance value of the power supply point 29 may be increased. As a result, the amount of heat generated increases. When thermal deformation occurs, the feeding point 29 changes, so that the wire protrusion length between the feeding point 29 and the work 8 changes. If the wire protrusion length changes, the voltage at the time of arc generation will increase or phenomenon will occur, and uniform power supply will be impeded, which will be a factor of lowering welding quality.
As described above, the heat generated in the power supply chip 27 causes the power supply chip 27 to be deteriorated, deformed, or the like, and the major factors contributing to the heat generation are the welding current and the welding voltage.

The feed amount of the wire also becomes one factor of the consumption of the power supply tip 27. Since the welding current during arc welding mainly varies depending on the wire feed amount, an increase or decrease in the wire feed amount during arc welding results in an increase or decrease in heat generation. Further, friction between the welding wire 28 and the power supply tip 27 also causes deformation. If the shape of the tip of the power supply tip 27 changes due to friction, the power supply point also moves. As described above, a change in the power supply point 29 causes a decrease in welding quality. Therefore, it can be said that if the wire supply amount is large, the consumption amount of the power supply tip 27 is large.
In addition, wire feeding is performed other than wire feeding during the welding period. For example, at the end of welding, a process such as cutting the tip of the welding wire 28 with a wire cutter or the like to maintain the shape of the tip of the welding wire 28 uniform and improve the stability of arc generation may be performed. . In this case, a certain length is fed even at the end of welding, and then the welding wire 28 is cut. As described above, even during wire feeding other than during non-welding, the power supply tip 27 is consumed due to friction. Therefore, even during non-welding, wire feeding causes the power supply tip 27 to be consumed.

The arc generation time is synonymous with the accumulated time during which heat is applied, and serves as a guideline indicating the consumption of the power supply chip 27. In addition, since the control for increasing the welding current only at the start of welding is generally used, even if the arc generation time is the same, the larger the number of arc generations, the greater the heat generation, and the faster the power supply tip 27 is consumed. Is done.
The number of welding failures also causes the power supply tip 27 to be consumed. For example, regarding welding failure due to arc break, the above-described control at the start of welding is performed every time an arc break occurs, and as a result, a conduction welding current increases and heat generation increases. Regarding the poor welding of the welding wire 28, a process for temporarily increasing the welding voltage significantly in order to cancel the welding is generally performed. As a result, the heat generation increases, and the power supply chip 27 also consumes a large amount.
As described above, the wear of the power supply chip 27 progresses due to various factors, and the degree of progress of the wear differs for each factor.

The wear factor measuring unit 21 measures each value of the wear factor, and stores the measured value in a buffer in the wear factor measuring unit for each predetermined measurement period. The welding current and the welding voltage are obtained by acquiring the current and voltage between the welding torch 3a and the work 8 at a predetermined sampling interval, and obtaining the instantaneous value of the acquired value, the average value within the measurement period, or the measurement period. To obtain the intermediate value within and use it as the measured value. The wire feed amount at the time of welding and the wire feed amount at the time of non-welding are obtained by acquiring the value of the encoder of the wire monitoring unit 5a attached to the wire feeding device 5 at a predetermined sampling interval, and calculating the displacement amount. Calculate the feed length from The feed amount is calculated by multiplying the calculated feed length by the specific gravity of the wire being used. The accumulated amount of the feed amount during the measurement period is set as a measured value. The number of times of arc generation is a measured value, which is the number of times an arc generation success signal is output from the welding machine 4 during the measurement period. The arc generation time measures the time during which the arc generation signal is output from the welding machine 4 within the measurement period. The number of welding failures is the number of times a welding failure occurrence signal has been notified from the welding machine 4 during the measurement period. If a different signal is output for each welding defect at this time, the number of times may be measured for each type of welding defect.
Note that the wear factor measuring unit 21 may acquire information about which wear factor is to be measured from the wear degree related information stored in the teaching information storage unit 11 and may measure only the specified wear factor. . Alternatively, the measurement may be performed based on information notified from the execution unit 12 or the input / output terminal 6 via a path (not shown). For example, with respect to the consumable factors acquired during welding, such as current and voltage, the measurement may be started after the notification of the start of welding is received from the execution unit 12, or may be always acquired. When an operation not caused by the consumption of the power supply chip 27, such as temporarily removing the power supply chip 27, is performed, the measurement stop is input to the input / output terminal 6 and a notification of the measurement stop is received from the input / output terminal 6. Then, the measurement may be stopped.
Further, when the consumption factor measurement unit 21 stores the measurement value in the internal buffer, the consumption degree calculation unit 22 may be notified of the completion of the measurement. Further, the measurement values may be stored in a plurality of storage areas such as a ring buffer for each measurement period, or may be notified after a predetermined number of measurement values are accumulated.
Further, the measurement period may be a predetermined fixed time, or may be, for example, a welding start and end period notified from the execution unit 12. Alternatively, a measurement period may be separately set for each wear factor.

The consumption degree calculation unit 22 calculates the consumption degree at regular intervals or when receiving a notification of completion of measurement from the consumption factor measurement unit 21. The consumption level in the present invention is a value obtained by multiplying the acquired measured value by a coefficient for each consumption factor in the consumption level related information. An example of calculating this degree of wear is shown in FIG. When there are a plurality of measured values for the same wear factor, the average value or the intermediate value of the collectively obtained measured values may be used for calculating the wear degree, or may be used separately.
The degree of wear is held in a buffer in the degree of wear calculation unit 22. If there is a degree of wear already held, the newly calculated degree of wear is added to the latest degree of wear, and the current date and time or the measured value is added. The given date and time information is added and held as the degree of wear. The buffer in the wear degree calculation unit 22 is realized by a storage medium such as a RAM, a flash memory, and a magnetic disk.
When the calculation of the degree of wear is completed, a notification of the completion of the calculation of the degree of wear may be sent to the replacement time calculating unit 24. Further, the wear level in the buffer may be cleared at an arbitrary timing notified from the input / output terminal 6. For example, when the replacement of the power supply chip 27 is completed and the completion of the replacement is input to the input / output terminal 6, the degree of wear in the replacement time calculation unit 24 may be cleared.

At a predetermined timing, the replacement time calculation unit 23 acquires the latest N wear degrees stored in the wear degree calculation unit 22 and a threshold value of the wear degree stored in the wear degree related information. The predetermined timing is either at a predetermined time or every time a notification of the completion of the consumption degree calculation is received from the consumption degree calculation unit 22. N is an integer of 2 or more, and may be the total number of stored degrees of wear or a number arbitrarily set by the user.
When the wear degree is acquired, the latest value is taken out of the acquired N wear degrees and compared with the wear degree threshold. At this time, if the degree of wear is equal to or more than the threshold of the degree of wear, a power supply chip replacement command is output to the replacement time output unit 24.
In the comparison, when the latest degree of wear is smaller than the threshold of the degree of wear, a regression analysis is performed as shown in FIGS. , A regression line or an approximate expression of a regression curve. At this time, N is an integer of 2 or more. After that, it is possible to estimate the date and time when the degree of wear reaches the threshold by using the wear level threshold, the intersection with the approximate straight line or the approximate curve in FIGS. 4 and 5, and output the wear level information to the replacement time output unit 24. Good. Note that the consumption level information output here may include any one of the date and time when the consumption level reaches the threshold, the latest N pieces of consumption level used in the calculation, or an approximate expression of a regression line and a regression curve. .
At this time, the regression analysis method may be either linear regression or curve regression, but not both. The date and time when the degree of wear reaches the threshold value, which is output to the replacement timing output unit 24, may be not both one of the date and time calculated by the approximate straight line and the date and time calculated by the approximate curve but both. Further, the wear degree information may be given to the power supply chip replacement command.
Also, in the method of regression analysis, in addition to linear regression and curve regression, any of known multivariate analysis methods may be used. May be obtained from.

When receiving the power supply chip replacement command from the replacement time calculation unit 23, the replacement time output unit 24 outputs information on replacement of the power supply chip 27 to the input / output terminal 6 or an automatic switchboard of the power supply chip 27 (not shown).
When the wear degree information is received from the replacement time calculation unit 23, one or both of the predicted replacement date and time and the number of days and time from the current date and time may be output from the wear degree information. When the replacement time output unit 24 outputs any of the above, the current consumption degree and the method used in the regression analysis may be output. As shown, the graph information of the change transition may be output, or the calculated approximate expression may be output. Also, the time taken for the degree of wear to change from 0 to the current value may be indicated.
The information output by the replacement time output unit 24 may be displayed on the display of the input / output terminal 6, an LCD or a 7Seg LED, or the replacement time may be output by voice or the like. In the case where the power supply chip 27 has an automatic exchange, when a power supply chip exchange command is received, a power supply chip exchange signal may be immediately output to the automatic exchange. When the estimated exchange date and time is included in the wear degree information, the date and time is held in a buffer in the exchange time output 24, and the time when the current date and time exceeds the estimated exchange date and time or is closer than a predetermined period. Then, a display urging replacement may be displayed on the display of the input / output terminal 6, or a power supply chip replacement signal may be output to the automatic exchange. The buffer in the replacement time output 24 is preferably a non-volatile storage medium such as a flash memory or a magnetic disk, but need not be.

  Note that the buffers of the respective units in the control device 1 and the consumables monitoring device 2 described above may use a common memory in the device or may hold them separately.

  Here, an example of a processing flow in the consumable supplies monitoring device 2 will be described. First, the processing flow of the wear factor measuring unit 21 will be used with reference to FIG. Note that the robot control device 1 other than the consumables monitoring device 2 will not be described as a generally known technique. In addition, the replacement time output unit 24 only performs output corresponding to the information acquired from the replacement time calculation unit 23, and as described above, detailed description of the processing is omitted.

  (Step S1) When the wear factor measuring unit 21 starts operation, the wear factor related information stored in the teaching information unit storage unit 11 is acquired, and from the information, which wear factor is to be measured is acquired. The operation may be started when the power is turned on, when a measurement command is input from the input / output terminal 6, or when the start of welding is notified from the execution unit 12.

  (Step S2) It is confirmed whether or not there is a wear factor to be acquired. If there is no consumable factor to be acquired, the process returns to step S1, and measurement is not performed until the acquisition target is specified.

  (Step S3) When there is an acquisition target, measurement of the consumption factor is started. The value is measured by the method of measuring the consumption factor shown in the preceding paragraph. For example, in the case of the current, the value of the current during welding is sampled every 50 msec.

  (Step S4) It is determined whether the measurement of the consumption factor is completed. In the present embodiment, it is assumed that a constant time value is continuously obtained, and it is determined that the measurement is completed after a predetermined time has elapsed. If it is determined that the measurement has not been completed, the process returns to step S3, and the measurement of the wear factor is continued. For example, an operation of continuously acquiring current for one second at a sampling interval of 50 msec is performed. At this time, in the present embodiment, the sampled currents are stored in different areas, respectively, and retain their values until the measurement is completed.

  (Step S5) When the measurement is completed, the measurement result is stored. At this time, one representative value may be obtained from the measured value of each consumption factor. The representative value is, for example, an average value or an intermediate value. For example, the average value of the current values obtained for one second may be used as the representative value.

(Step S <b> 6) When the measurement is completed, a notification of the completion of the measurement may be sent to the wear degree calculation unit 22. After that, the process returns to step S1 to perform the next measurement.
At this time, the operation may be terminated, and the measurement may not be performed until the next measurement start command comes.

Next, the flow of the process of the wear degree calculation unit 22 will be described with reference to FIG.
(Step S7) When started, the consumption degree calculation unit 22 waits until the measurement of the consumption factor measurement unit 21 is completed. The condition for determining the completion of the measurement may be a notification of the completion of the measurement from the consumption factor measuring unit 21.

  (Step S8) When it is determined that the measurement is completed, the measured value stored by the consumption factor measuring unit 21 is acquired. At this time, the read value may be cleared in the buffer in which the measuring unit of the wear factor measuring unit 21 is stored, or the fact that the clear may be notified to the wear factor measuring unit 21.

  (Step S9) A coefficient for each wear factor is acquired from the wear degree related information.

  (Step S10) The degree of wear is calculated. Multiply the obtained measured value and coefficient for each consumable factor, and accumulate all values. The result is taken as the degree of consumption within the time measured by the consumption factor measuring unit 21.

  (Step S11) The previously calculated consumption level is read from the buffer in the consumption level calculation unit 21, and if there is no value, the value is stored as it is. If there is a degree of wear calculated in the past, the value is read out, the newly calculated degree of wear is added, and additionally stored in the buffer. At this time, the date and time information may be added to the degree of wear and stored, and the date and time information may be the time when the wear factor measuring unit 21 completes the measurement, or the current date and time obtained from a calendar or a clock unit (not shown). Good.

  (Step S12) When the saving of the consumption level is completed, a notification of the completion of saving the consumption level may be sent to the replacement time calculating unit 23. Thereafter, the process returns to step S7, and the processing is continued.

Next, the process of the replacement time calculation unit 23 will be described with reference to FIG.
(Step S13) It waits until the consumption degree calculation unit 22 completes saving the consumption degree. The condition for judging that the saving of the degree of wear has been completed may be to receive a saving completion notification.

  (Step S14) The latest N wear levels are acquired. N is an integer of 2 or more, and may be the number of wear levels measured after replacing the power supply chip 27 before, the number of all wear levels acquired in the past, or arbitrarily determined by the user. May be the number.

  (Step S15) A wear level threshold is acquired from the wear level related information. At this time, if no particular threshold is set, the threshold may not be acquired. Further, the number of thresholds is not limited to one, and a plurality of thresholds may be provided. For example, a first threshold and a second threshold that is set to a value larger than the first threshold are provided, and when only the first threshold is exceeded, only a screen that prompts replacement of the power supply chip 27 is displayed. When the second threshold value is exceeded, the warning level for exceeding the threshold value may be divided, for example, an exchange command is immediately notified.

  (Step S16) The acquired threshold value is compared with the latest wear degree.

  (Step S17) If the degree of wear exceeds the threshold, a power supply chip replacement command is output to the replacement time output unit 24. At this time, the read exchange degree may be included in the notified exchange instruction. Thereafter, the process returns to step S13 and waits for the next notification.

  (Step S18) If the degree of wear does not exceed the threshold, regression analysis is performed on the read degree of wear to calculate an increase transition of the degree of wear. At this time, the regression analysis may be a linear regression or a curve regression. In addition, it is not necessary to use all the wear levels of the past N pieces. For example, only the number M smaller than the past N may be used, or only a significant value excluding outliers or the like may be used. Then, a period until the threshold value is reached is calculated for the increase transition of the degree of wear. The period calculated at this time may be either the number of days until the threshold value is exceeded or the time. Alternatively, the number of days and time in the previous period may be added to the date and time of acquisition of the latest degree of wear to acquire date and time information that reaches a threshold.

  (Step S19) The result of the regression analysis performed in step S19 is output to the replacement time output unit 24 as wear degree information. The exhaustion degree information may include at least one of a regression line and a regression curve calculation formula indicating the increase transition of the exhaustion degree, the number of days and the time until the threshold value is exceeded, or the date and time information exceeding the threshold value.

As described above, according to the consumables monitoring apparatus 2 according to the present embodiment, in each welding phenomenon that contributes to the wear in the power supply tip 27, the numerical value indicating how much the wear has progressed is measured. Can also be calculated based on past results. Therefore, for example, the replacement timing of the power supply tip 27 can be determined more accurately than when only the arc-on time, the number of arc occurrences, and the accumulated value of the wire feed amount are determined. As a result, by using the exchange information output by the consumables monitoring device 2, the power supply chip 27 can be replaced in a timely manner, and the power supply chip 27 is replaced before it is consumed. It is possible to prevent the increase in the inspection time and the yield due to the increase and the welding while the power supply tip 27 is worn out, and the deterioration of the welding quality.
In addition, since the replacement time can be estimated, the power supply chip 27 stored as a maintenance part can be replenished systematically, and it is possible to prevent unnecessary large purchases or shortages.

  Note that, in the present embodiment, it is assumed that there is one power supply tip 27, but a plurality of power supply tips may be provided as in the case of welding using a plurality of electrodes. In this case, the degree of wear may be provided for each of the main electrode and the sub-electrode, and coefficients for calculation may be provided for the main electrode and the sub-electrode.

  In the present embodiment, the case where the consumable to be replaced is the power supply tip used when using the consumable electrode is described, but the present invention is not limited to this. For example, a non-consumable electrode in welding using a non-consumable electrode such as a tungsten electrode used for TIG welding or the like may be used. In this case, since the wire is not fed, the wear factor of the wire feed amount in the wear factor measurement is not measured, and the coefficient by which the wear factor is multiplied may be set to zero. In addition, as a method of arc start in TIG welding, a method called lift start, in which the tip of a non-consumable electrode is brought into contact with a work, or a normal arc start, in which the arc is started with the electrode and work separated, is used. There are two types. In these two types of arc start methods, a difference occurs in the current that is conducted at the time of arc start and the applied voltage, and as a result, contributes to a difference in consumption due to heat generation of the non-consumable electrode. For this reason, the number of arc occurrences may be measured separately for two types: lift start number and normal arc occurrence number. Similarly, there are two types of consumable electrodes: a touch start in which the welding wire is pulled up from a state in which the welding wire is in contact with the work at the start of the arc, and a normal arc start in which the arc is started while the welding wire and the work are spoken. . In this case, similarly, a difference occurs between the current that is conducted at the time of arc start and the applied voltage, so that the power supply chip 27 is consumed differently. Therefore, even in the case of a consumable electrode, the number of arc occurrences may be measured separately for two types.

  Further, the consumable to be replaced does not need to be an electrode, but may be a component used in a wire feeding path. For example, a conduit cable (not shown) connected with a welding wire inserted from a wire reel (not shown) to the feeding device 5, a feeding roller (not shown) used for the feeding device 5, A power cable 7 or the like connected with the welding wire inserted from the device 5 to the welding torch 3a may be used. These consumables, whether during welding or non-welding, are consumed only due to the feed rate of the wire. Therefore, only the wear factor of the wire feed amount is measured, and the wear factor other than the wire feed amount is not measured, and the coefficient may be set to zero.

  In addition, the measurement of the consumption level of each consumable item described above may be set to any one of them, or may be simultaneously measured as different degrees of consumption.

  As described above, according to the consumable supply monitoring device of the present invention, it is possible to obtain an effect that information for timely replacement of consumables can be output, which is useful, for example, as a device included in a robot control device.

101 Welding robot system 1 Robot controller 2 Consumables monitoring device 3 Welding robot 3a Welding torch 4 Welding machine 5 Feeding device 5a Feeding speed measuring unit 6 Acquisition terminal 7 Power cable 11 Teaching information storage unit 12 Execution unit 13 Servo control Unit 14 welding control unit 21 wear factor measurement unit 22 wear degree calculation unit 23 replacement time calculation unit 24 replacement time output unit

Claims (1)

In the consumables monitoring device that monitors the replacement time of the consumables of the arc welding device,
A consumable factor measuring unit for measuring a value of a consumable factor of the consumable,
A wear degree calculation unit that calculates the wear degree of the consumable based on the measured value of the wear factor,
An exchange time calculation unit that estimates a period until the accumulated value of the consumption degree reaches a predetermined threshold, and calculates an exchange time of the consumable.
An exchange time output section for outputting the calculated exchange time to the outside,
Equipped with a,
The consumables monitoring device, wherein the replacement time calculation unit estimates a period until the threshold is reached, based on the degree of wear recorded in the past .

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