JP2013022598A - Abnormality diagnostic method and abnormality diagnostic device of lap seam welder - Google Patents

Abstract

An object of the present invention is to accurately detect an abnormality in an electrode wheel.
An abnormality diagnosis device 12 uses a thermometer 10 to measure a temperature distribution of a welded portion in a welding width direction along a width direction of a steel plate. The abnormality diagnosis device 12 uses the electrode wheel rotation position detection sensor 11 to measure the rotation position of the electrode wheel when the temperature distribution of the welded portion is measured. The abnormality diagnosis device 12 measures the welding width direction measured. The abnormality of the electrode wheel is detected based on the temperature distribution of the part and the rotation position of the electrode wheel. Further, the abnormality diagnosis device 12 detects an attachment position abnormality of the electrode wheel based on the maximum temperature of the temperature distribution of the welded portion and the position in the weld width direction where the temperature of the welded portion becomes the maximum temperature. Thereby, the abnormality of the electrode wheel can be detected with high accuracy.
[Selection] Figure 1

Description

  The present invention relates to an abnormality diagnosis method and an abnormality diagnosis apparatus for a lap seam welder.

  In the continuous cold treatment line, the tail end of the preceding steel plate is superposed on the tail end of the preceding steel plate and the tip of the succeeding steel plate, and energized with the electrode wheels pressed above and below the overlapped portion. And the tip of the subsequent steel plate are welded. In such a continuous cold treatment line, when a defect occurs in the welded portion, the welded portion may break and the operation of the line may stop. For this reason, in a continuous cold processing line, it is desirable to judge the quality of a welding part and to perform measures, such as re-welding, when a defect is detected in a welding part. One of the causes of defective welds is wear deterioration of the electrode wheels.

  From such a background, a technique for diagnosing surface abnormality or wear of the electrode wheel and grinding the electrode wheel based on the diagnosis result has been proposed. Specifically, in Patent Document 1, the temperature distribution of the welded part immediately after welding is measured, and the width of the part that has reached the welding heating temperature is detected as the bead width from the measured temperature distribution. A technique is described in which it is determined that an abnormality has occurred in the electrode wheel when there is a correlation between the wavelength of the direction distribution and the circumference of the electrode wheel. Patent Document 2 discloses a technique for measuring the temperature of a welded portion along the width direction of the steel sheet and detecting the deterioration state of the electrode wheel based on the number of times that the temperature of the welded portion has a sharp temperature fluctuation exceeding a threshold value. Is described.

JP 09-267182 A JP 06-198454 A

  However, in order for the wavelength of the bead width in the steel plate width direction distribution to correlate with the circumferential length of the electrode ring, the electrode ring surface abnormality needs to continuously occur in the circumferential direction of the electrode ring. However, the surface abnormality of the electrode ring occurs due to local factors such as spatter adhesion and dents. For this reason, according to the technique of patent document 1, the discontinuous or local electrode ring surface abnormality which cannot detect the wavelength of the steel plate width direction distribution of a bead width cannot be detected. On the other hand, steep temperature fluctuations are caused not only by deterioration of the electrode ring, but also by various factors such as electrode wheel position shift (vertical direction, welding width direction), and fluctuation of contact resistance between the electrode ring and the steel plate. To do. For this reason, according to the technique of patent document 2 which detects the deterioration state of an electrode ring based on a steep temperature fluctuation, the deterioration of an electrode ring cannot be detected accurately.

  The present invention has been made in view of the above problems, and an object of the present invention is to provide an abnormality diagnosis method and an abnormality diagnosis apparatus for a lap seam welder that can accurately detect abnormality of an electrode wheel.

  In order to solve the above-mentioned problems and achieve the object, the abnormality diagnosis method of the lap seam welder according to the present invention superimposes the lengthwise end of the preceding steel plate and the lengthwise end of the succeeding steel plate, An abnormality diagnosis method for a lap seam welder that welds lengthwise ends by energizing in a state in which the electrode wheel is pressed above and below the overlapped portion, and in the welding width direction along the width direction of the steel sheet A temperature distribution measuring step for measuring the temperature distribution of the welded portion, a rotational position measuring step for measuring the rotational position of the electrode ring when measuring the temperature distribution of the welded portion, and the welding measured in the temperature distribution measuring step. A diagnostic step of detecting an abnormality of the electrode wheel based on the temperature distribution of the part and the rotational position of the electrode wheel measured in the rotational position measuring step.

  In the lap seam welder abnormality diagnosis method according to the present invention, in the above invention, the diagnosis step determines whether or not the maximum temperature of the temperature distribution is outside a predetermined range, and the maximum temperature is outside the predetermined range. In some cases, the method includes a step of determining that a welding failure has occurred at a position in the width direction of the steel plate where the temperature distribution is measured.

  The abnormality diagnosis method for a lap seam welder according to the present invention is the above invention, wherein the diagnosis step specifies the rotational position of the electrode wheel corresponding to the width direction position of the steel sheet determined that a welding failure has occurred. If it is determined that the welding failure has occurred for the second predetermined number of times or more while the electrode wheel rotates for the first predetermined number of times at the specified rotational position of the electrode wheel, it is determined that the abnormality of the electrode wheel has occurred. Including the steps of:

  In the lap seam welder abnormality diagnosis method according to the present invention, in the above invention, when it is determined in the diagnosis step that an abnormality in the electrode wheel has occurred, alarm information indicating that an abnormality in the electrode wheel has occurred Is included.

  The abnormality diagnosis method for a lap seam welder according to the present invention is the above invention, wherein the maximum temperature of the temperature distribution of the welded portion measured in the temperature distribution measuring step and the position in the weld width direction at which the temperature of the welded portion becomes the maximum temperature, And detecting an abnormality in the mounting position of the electrode wheel.

  In order to solve the above-described problems and achieve the object, the abnormality diagnosis device for a lap seam welder according to the present invention superimposes the lengthwise end of the preceding steel plate and the lengthwise end of the subsequent steel plate, An abnormality diagnosis device for a lap seam welder that welds lengthwise ends by energizing in a state in which the electrode wheel is pressed above and below the overlapped portion, in the welding width direction along the width direction of the steel sheet Temperature distribution measuring means for measuring the temperature distribution of the welded portion, rotational position measuring means for measuring the rotational position of the electrode ring when measuring the temperature distribution of the welded portion, and welding measured by the temperature distribution measuring means Diagnostic means for detecting an abnormality of the electrode wheel based on the temperature distribution of the part and the rotational position of the electrode wheel measured by the rotational position measuring means.

  According to the abnormality diagnosis method and abnormality diagnosis apparatus for a lap seam welder according to the present invention, it is possible to accurately detect abnormality of an electrode wheel.

FIG. 1 is a schematic diagram showing a configuration of an abnormality diagnosis system for a lap seam welder according to an embodiment of the present invention. FIG. 2 is a diagram illustrating an example of a temperature distribution of a welded portion in the welding lap direction along the steel plate width direction. FIG. 3 is a flowchart showing a flow of surface abnormality diagnosis processing according to an embodiment of the present invention. FIG. 4 is a diagram illustrating an example of a change in the maximum temperature of the welded portion accompanying a change in the width direction position of the steel plate. FIG. 5 is a diagram showing an example of the defect candidate data shown in FIG. FIG. 6 is a view for explaining a state where the welding lap cost is reduced due to an abnormal attachment position of the electrode wheel. FIG. 7 is a diagram illustrating an example of a change in welding temperature variation accompanying a change in welding lap cost. FIG. 8 is a flowchart showing the flow of an attachment abnormality diagnosis process according to an embodiment of the present invention. FIG. 9 is a diagram for explaining an attachment abnormality diagnosis process based on the maximum temperature of the temperature distribution of the welded portion and the position in the weld width direction where the temperature of the welded portion becomes the highest. FIG. 10 is a plan photograph view and an enlarged photograph view of the electrode ring. FIG. 11 is a diagram showing the temperature distribution of the weld in the weld lap direction along the steel plate width direction.

  Hereinafter, a configuration and operation of an abnormality diagnosis system for a lap seam welder according to an embodiment of the present invention will be described with reference to the drawings.

[Configuration of abnormality diagnosis system for lap seam welders]
First, with reference to FIG. 1, the structure of the abnormality diagnosis system of the lap seam welder which is one Embodiment of this invention is demonstrated.

  FIG. 1 is a schematic diagram showing a configuration of an abnormality diagnosis system for a lap seam welder according to an embodiment of the present invention. An abnormality diagnosis system for a lap seam welder according to an embodiment of the present invention diagnoses an abnormality of a lap seam welder. As shown in FIG. 1, the lap seam welder includes a pair of electrode wheels 1a and 1b. The pair of electrode wheels 1a and 1b apply electric power while pressing the overlapping portion (wrap portion) of the preceding steel plate 2a and the succeeding steel plate 2b with the end portions in the length direction being overlapped from above and below. The leading steel plate 2a and the succeeding steel plate 2b are moved in the width direction by a driving device (not shown). Thereby, a pair of electrode wheel 1a, 1b is the length direction edge part (tail end) of the preceding steel plate 2a and the length direction edge part (front-end | tip) of the succeeding steel plate 2b in the width direction of the preceding steel plate 2a and the succeeding steel plate 2b. ) To join the preceding steel plate 2a and the succeeding steel plate 2b.

  The abnormality diagnosis system for a lap seam welder according to an embodiment of the present invention includes a thermometer 10, an electrode wheel rotation position detection sensor 11, an abnormality diagnosis device 12, and an output device 13. The thermometer 10 has a field of view R that is sufficiently wider than the overlapped portion of the preceding steel plate 2a and the succeeding steel plate 2b in order to measure the temperature distribution of the weld in the welding width direction. The thermometer 10 is installed in the vicinity of the exit side of the electrode wheel 1b in order to measure the temperature of the welded part immediately after welding. The thermometer 10 moves in the steel plate width direction as the electrode wheel 1b moves in the steel plate width direction. Thereby, the thermometer 10 can measure the temperature distribution of the welding part along the steel plate width direction as shown in FIG. The thermometer 10 functions as a temperature distribution measuring unit according to the present invention.

  The electrode wheel rotation position detection sensor 11 is constituted by a rotation angle sensor such as a resolver. The electrode wheel rotation position detection sensor 11 detects the rotation position of the electrode wheel 1 b and inputs information on the detected rotation position to the abnormality diagnosis device 12. The electrode wheel rotational position detection sensor 11 functions as rotational position measuring means according to the present invention. Since the electrode wheel 1a is connected to the electrode wheel 1b via a gear and rotates in synchronization with the electrode wheel 1b, it is not necessary to detect the rotation position of the electrode wheel 1a.

  The abnormality diagnosis apparatus 12 is configured by an information processing apparatus such as a microcomputer or a personal computer, and includes a storage unit 121 and a control unit 123. The storage unit 121 is configured by a nonvolatile storage device such as a ROM. The storage unit 121 includes various control data necessary for abnormality diagnosis processing of the lap seam welder, such as data on the temperature distribution of the weld measured by the thermometer 10 and defect candidate data 122 created in abnormality diagnosis processing described later. A control program is stored. The control unit 123 is configured by an arithmetic processing device such as a CPU. The control unit 123 controls the overall operation of the abnormality diagnosis device 12 according to a control program stored in the storage unit 121. The abnormality diagnosis device 12 functions as a diagnostic unit according to the present invention.

  The output device 13 includes a display device, a printing device, an audio output device, and the like. The output device 13 outputs the abnormality diagnosis processing result of the abnormality diagnosis device 12.

  The abnormality diagnosis system for a lap seam welder having such a configuration diagnoses the surface abnormality of the electrode wheel 1a or the electrode wheel 1b by executing the following surface abnormality diagnosis process. The operation of the abnormality diagnosis system for the lap seam welder when executing the surface abnormality diagnosis process will be described below with reference to the flowchart shown in FIG.

[Surface abnormality diagnosis processing]
FIG. 3 is a flowchart showing a flow of surface abnormality diagnosis processing according to an embodiment of the present invention. The flowchart shown in FIG. 3 starts at the timing when the welding process is started, and the surface abnormality diagnosis process proceeds to step S1.

  In the process of step S1, the thermometer 10 measures the temperature distribution of the welded portion in the weld width direction along the steel plate width direction, and the abnormality diagnosis device 12 uses the temperature distribution data of the welded portion measured by the thermometer 10. Is stored in the storage unit 121. Thereby, the process of step S1 is completed and the surface abnormality diagnosis process proceeds to the process of step S2.

  In the process of step S2, the abnormality diagnosis device 12 determines whether or not the maximum temperature of the temperature distribution measured by the process of step S1 is outside the predetermined range. If the maximum temperature is outside the predetermined range, the temperature distribution The position in the width direction of the steel plate on which is measured is specified as a defect candidate position. Specifically, in the example illustrated in FIG. 4, the abnormality diagnosis device 12 specifies the position in the width direction of the steel sheet whose maximum temperature of the temperature distribution is not within the range between the lower limit temperature Tmin and the upper limit temperature Tmax as the defect candidates 1 to 5. doing. Thereby, the process of step S2 is completed, and the surface abnormality diagnosis process proceeds to the process of step S3.

  In the process of step S3, the abnormality diagnosis device 12 uses the detection signal of the electrode wheel rotation position detection sensor 11 to rotate the rotation position (circumference) of the electrode wheel 1b corresponding to the defect candidate position specified by the process of step S2. Position). Thereby, the process of step S3 is completed, and the surface abnormality diagnosis process proceeds to the process of step S4.

  In the process of step S4, the abnormality diagnosis device 12 increments the value corresponding to the rotation position (circumferential position) of the electrode wheel specified by the process of step S3 in the defect candidate data 122 shown in FIG. Thus, the defect candidate position and the rotation position (circumferential position) of the electrode wheel 1b are stored in association with each other. Note that the defect candidate data shown in FIG. 5 indicates the rotation position (circumferential position) of the electrode ring in which the defect candidate position is specified in the latest four rotation operations of the electrode ring. The defect candidate data shown in FIG. 5 indicates that a welding failure was detected at a circumferential position of 30 mm before 1 rotation and 4 rotations, and a welding failure was detected at a circumferential position of 570 mm before 1 to 4 rotations. . Thereby, the process of step S4 is completed, and the surface abnormality diagnosis process proceeds to the process of step S5.

  In the process of step S5, the abnormality diagnosis device 12 performs the second predetermined process during the rotation operation of the electrode wheel for the first predetermined number of times (four rotations in the example shown in FIG. 5) based on the defect candidate data after the process of step S4. It is determined whether or not there is a rotational position (circumferential position 570 mm in the example shown in FIG. 5) of the electrode wheel 1b where the welding failure has occurred more than the number of times (for example, 3 times). When there is such a rotation position of the electrode wheel 1b, the abnormality diagnosis device 12 determines that an abnormality has occurred in the electrode wheels 1a and 1b. Thereby, the process of step S5 is completed, and the surface abnormality diagnosis process proceeds to the process of step S6.

  In the process of step S6, the abnormality diagnosis device 12 outputs the determination result of step S5 to the output device 13. Thereby, a series of surface abnormality diagnosis processing ends.

  As is apparent from the above description, according to the surface abnormality diagnosis process that is one embodiment of the present invention, the abnormality diagnosis device 12 is based on the temperature distribution of the weld in the welding width direction and the rotational position of the electrode ring. Since the abnormality of the electrode wheel is detected, the abnormality of the electrode wheel can be detected with high accuracy.

[Mounting abnormality diagnosis processing]
There is a high need for ultra-thin steel plates for tin cans. However, when the steel plate is made extremely thin, the risk of poor welding is 10 times or more the normal plate thickness. For this reason, in the steel sheet for ultra-thin cans, the energization current at the time of welding is set small so as not to cause excessive heat input. However, even if the energization current at the time of welding is reduced, if there is an abnormality in the mounting position of the electrode wheel, the welding lap allowance (the overlap width of the steel plates) due to buckling as shown in FIGS. ) Is likely to result in insufficient heat input. Moreover, in the steel sheet for ultrathin cans, when the welding lap cost decreases, the welding temperature fluctuation increases as shown in FIG. Therefore, the lap seam welder abnormality diagnosis system according to an embodiment of the present invention diagnoses an electrode wheel mounting abnormality during electrode wheel replacement by executing the following mounting abnormality diagnosis process. Hereinafter, with reference to the flowchart shown in FIG. 8, the abnormality diagnosis system of the lap seam welding machine at the time of performing an attachment abnormality diagnosis process is demonstrated.

  FIG. 8 is a flowchart showing the flow of an attachment abnormality diagnosis process according to an embodiment of the present invention. The flowchart shown in FIG. 8 starts at the timing when the test welding after the replacement of the electrode wheel is started, and the attachment abnormality diagnosis process proceeds to the process of step S11.

  In the process of step S11, the abnormality diagnosis device 12 detects the position in the width direction of the steel sheet where the maximum temperature Tmax of the temperature distribution of the welded portion is outside the normal range shown in FIG. 9A, and the maximum temperature distribution of the welded portion is detected. The ratio Nt-max% of the number of the steel sheet in the width direction where the temperature Tmax is outside the normal range occupies the total width of the steel sheet is calculated. Then, the abnormality diagnosis device 12 determines whether or not the calculated ratio Nt-max% is equal to or greater than a predetermined value. If the calculated ratio Nt-max% is equal to or greater than the predetermined value, the abnormality diagnosis apparatus 12 performs an attachment abnormality diagnosis process. Proceeding to the process of step S13, if the calculated ratio Nt-max% is less than the predetermined value, the attachment abnormality diagnosis process is advanced to the process of step S12.

  In the process of step S12, the abnormality diagnosis device 12 detects the position in the width direction of the steel plate where the weld width direction position Xpeak at which the temperature of the weld reaches the maximum is outside the normal range shown in FIG. The ratio Nx−peak%, in which the number of positions in the width direction of the steel plate where the weld width direction position Xpeak at which the temperature is highest falls outside the normal range occupies the total width of the steel plate, is calculated. Then, the abnormality diagnosis device 12 determines whether or not the calculated ratio Nx-peak% is equal to or greater than a predetermined value. If the calculated ratio Nx-peak% is equal to or greater than the predetermined value, the abnormality diagnosis device 12 performs an attachment abnormality diagnosis process. Proceeding to the process of step S13, if the calculated ratio Nx-peak% is less than the predetermined value, the attachment abnormality diagnosis process is advanced to the process of step S13.

  In the process of step S13, the abnormality diagnosis device 12 determines that an electrode wheel attachment abnormality has occurred. Thereby, the process of step S13 is completed and the attachment abnormality diagnosis process proceeds to the process of step S14.

  In the process of step S14, the abnormality diagnosis device 12 outputs the determination result of step S13 to the output device 13. Thereby, a series of attachment abnormality diagnosis processing ends.

〔Example〕
Finally, examples of surface abnormality diagnosis processing and attachment abnormality diagnosis processing according to an embodiment of the present invention will be described.

  FIGS. 10A and 10B are a plan photograph of the electrode wheel from which the defect candidate data shown in FIG. 5 was obtained and an enlarged photograph of the region A shown in FIG. The defect candidate data shown in FIG. 5 indicates that there is a welding defect at the circumferential position 570 mm of the electrode ring. Then, when the electrode ring was actually confirmed visually, it was confirmed that the spatter adhered to the circumferential position 570 mm of the electrode ring. Therefore, the spatter was removed by grinding.

  FIG. 11 is a diagram showing the temperature distribution of the weld in the weld lap direction along the steel plate width direction. As shown in FIG. 11, there is a steel plate width direction position where the maximum temperature of the temperature distribution is out of the normal range due to the slight shift of the mounting position of the electrode ring 1 a downward when replacing the electrode ring. confirmed. For this reason, it adjusted so that the maximum temperature of temperature distribution may fall in a normal range by adjusting the attachment position of an electrode ring.

DESCRIPTION OF SYMBOLS 1a, 1b Electrode wheel 2a Leading steel plate 2b Subsequent steel plate 10 Thermometer 11 Electrode wheel rotation position detection sensor 12 Abnormality diagnosis device 13 Output device 121 Storage unit 122 Defect candidate data 123 Control unit

Claims (6)

The lengthwise ends of the preceding steel plate and the lengthwise end of the succeeding steel plate are overlapped, and the lengthwise ends are welded by energizing the electrodes while pressing the electrode wheels above and below the overlapped portion. An abnormality diagnosis method for a lap seam welder,
A temperature distribution measuring step for measuring the temperature distribution of the weld in the weld width direction along the width direction of the steel sheet;
A rotational position measuring step for measuring the rotational position of the electrode wheel when measuring the temperature distribution of the weld;
A diagnostic step for detecting an abnormality of the electrode wheel based on the temperature distribution of the weld measured in the temperature distribution measurement step and the rotation position of the electrode wheel measured in the rotation position measurement step;
An abnormality diagnosis method for a lap seam welder characterized by comprising:   The diagnosis step determines whether or not the maximum temperature of the temperature distribution is outside a predetermined range, and if the maximum temperature is outside the predetermined range, poor welding at the position in the width direction of the steel sheet where the temperature distribution is measured. The method for diagnosing abnormality of a lap seam welder according to claim 1, further comprising the step of determining that the occurrence has occurred.   The diagnosis step specifies a rotation position of the electrode wheel corresponding to a position in the width direction of the steel plate determined that a welding failure has occurred, and the electrode wheel rotates a first predetermined number of times at the specified rotation position of the electrode wheel. 3. The lap seam welding according to claim 2, further comprising a step of determining that an abnormality in the electrode wheel has occurred when it is determined that a welding failure has occurred for a second predetermined number of times or more during the operation. Machine abnormality diagnosis method.   4. The method according to claim 1, further comprising a step of outputting alarm information indicating that an abnormality in the electrode wheel has occurred when it is determined in the diagnostic step that an abnormality in the electrode wheel has occurred. An abnormality diagnosis method for a lap seam welder according to any one of the preceding claims.   Detecting a mounting position abnormality of the electrode ring based on the maximum temperature of the temperature distribution of the welded portion measured in the temperature distribution measuring step and the weld width direction position at which the temperature of the welded portion becomes the maximum temperature. The abnormality diagnosis method for a lap seam welder according to any one of claims 1 to 4, wherein the abnormality diagnosis method is provided. The lengthwise ends of the preceding steel plate and the lengthwise end of the succeeding steel plate are overlapped, and the lengthwise ends are welded by energizing the electrodes while pressing the electrode wheels above and below the overlapped portion. An abnormality diagnosis device for a lap seam welder,
Temperature distribution measuring means for measuring the temperature distribution of the weld in the welding width direction along the width direction of the steel sheet;
Rotational position measuring means for measuring the rotational position of the electrode wheel when measuring the temperature distribution of the weld,
Diagnostic means for detecting an abnormality of the electrode wheel based on the temperature distribution of the weld measured by the temperature distribution measuring means and the rotational position of the electrode wheel measured by the rotational position measuring means;
An abnormality diagnosis device for a lap seam welding machine, comprising: