JP2019124560A - Appearance evaluation method and appearance evaluation device for weld bead - Google Patents

Abstract

To provide an appearance evaluation method and an appearance evaluation device for a weld bead that can evaluate the position of the weld bead with high precision continuously along a longer direction of the weld bead even if an undetectable section or an uncertain section is generated in detecting the position of an end part of the weld bead along the longer direction of the weld bead.SOLUTION: An appearance evaluation method for a weld bead comprises: a work shape detection step of detecting information on surface shapes W1, W2, W3, ..., Wn of a work 5 in an X direction of the weld bead 51 over a measurement width D1 by detection means along a Y direction of the weld bead; a measurement end part data generation step of detecting a rising position of the weld bead as a measurement end part and plotting it along the Y direction of the weld bead; and an approximate end part calculation step of specifying the position of a bead end part 51a by approximating data on the plotted measurement end part to a straight line or curved line along the Y direction of the weld bead and then calculating an approximate end part after interpolation between data on the measurement end part.SELECTED DRAWING: Figure 4

Description

  The present invention relates to a method and an apparatus for evaluating the appearance of a weld bead, and more particularly to a method and an apparatus for evaluating the appearance of a weld bead by a detection method using an optical means.

  One of the conventional weld bead appearance evaluation methods is a method of detecting the surface shape of the weld bead using optical means. For example, as shown in Patent Document 1, the calculation processing range was calculated for the calculation processing range after setting the calculation processing range corresponding to the position range of one end and the other end forming the outer surface seam portion of the tack welded steel pipe. A detection method is used to calculate the positions of the seam edge portion at one end and the seam edge portion at the other end based on the displacement amount less than a predetermined threshold among the displacement amounts of the cross-sectional shapes at one end and the other end There is.

  Further, as shown in Patent Document 2, a base material estimation section is formed on the first base material or / and the second base material of the cross-sectional profile including the first base material or / and the second base material and the weld bead, and A weld bead inspection method is used which detects a bead edge in a bead edge search section using a base material estimation curve estimated from data of a cross section profile in the base material estimation section after setting a base material section consisting of a bead edge search section. ing.

JP, 2015-100838, A JP, 2010-025818, A

  The evaluation of the appearance of the weld bead requires an accurate determination of the position of the bead end, and the detection error of the position of the bead end can greatly affect the error in the evaluation of the shape of the weld bead. In particular, when there is almost no level difference between the bead end and the base material, it is difficult to accurately perform the detection method using an optical means. In addition, in the case where the measurement conditions vary, or in the case where there is an uneven shape other than the weld bead on the surface of the work, it becomes difficult to specify the position of the bead end.

  For example, in lap joint welding and butt welding, the position of the bead end and the base material are low when the height of the bead end position is low and the shape change between the bead end and the base material is gradual. Because of the small difference in shape between them, detection of the position of the bead end tends to be difficult. In addition, when there is a convex structure other than the bead, such as sputtering, in the vicinity of the position of the bead end, erroneous detection of the position of the bead end by recognizing the convex structure as rising of the bead end becomes a problem. . Above all, when detecting the position of the end of the weld bead formed over a certain length, it is likely to be difficult to accurately detect the position of the bead end over the entire area in the longitudinal direction.

  In Patent Document 1, the position of the seam edge portion at one end and the other end is calculated based on the displacement amount of the cross-sectional shape of the one end and the other end with respect to the position change in the outer circumferential direction of the steel pipe. There is. However, when the change in the cross-sectional shape is gradual, the displacement amount may be extremely small and the seam edge portion may not be calculated.

  Moreover, in patent document 2, the bead edge in a bead edge search area is detected for every cross-sectional profile, When a bead edge is not detected, a bead edge search area is moved only an arbitrary section width to a bead side, and a bead edge search section is detected. The bead edge is detected by updating. However, if the change in cross-sectional shape between the base material and the bead edge is gradual, even if the bead edge search section is updated, the bead edge may not be detected or an error may occur in the position of the bead edge.

  Furthermore, in any case of Patent Literatures 1 and 2, if a detection jump or detection error occurs at the time of seam edge or bead edge detection, the position of the seam edge or bead edge is not detected, or an error is detected at the detected position. May occur. As described above, Patent Literatures 1 and 2 do not disclose methods for coping with the occurrence of a location where a seam edge or bead edge can not be detected or an incorrect location.

  The problem to be solved by the present invention is that, when detecting the position of the end of the weld bead along the longitudinal direction of the weld bead, the bead end may be detected even if a portion that can not be detected or an incorrect portion occurs. It is an object of the present invention to provide a method and an apparatus for evaluating the appearance of a weld bead which can be evaluated with high accuracy continuously along the longitudinal direction of the weld bead.

  In order to solve the above problems, in the method of evaluating the appearance of a weld bead according to the present invention, the weld bead is irradiated with light at the position of the bead end which is the rising end of the weld bead formed on the surface of the work. In the method of evaluating the appearance of a weld bead using detection means for detecting the reflected light generated by the operation, information on the surface shape of the workpiece including the weld bead in the direction intersecting the longitudinal direction of the weld bead is the weld bead A work shape detection step of detecting along the longitudinal direction of the weld bead by the detection means over a measurement width along a direction intersecting the longitudinal direction of the weld; and the longitudinal length of the weld bead included in the information of the surface shape of the workpiece The position of the rising of the weld bead in the direction intersecting the direction is detected as the measuring end, in the longitudinal direction of the weld bead Between the measurement end data generation step for plotting and the measurement end portion data plotted by approximating to a straight line or a curve along the longitudinal direction of the weld bead An approximate end calculation step of specifying the position of the bead end by calculating the approximate end is a gist.

  Here, the measurement end data creation step differentiates the height of the weld bead in the workpiece along a direction intersecting the longitudinal direction of the weld bead, and the absolute value of the differential value is a predetermined threshold value. The above position may be regarded as the measurement end.

  In the first case where the measurement end is detected in the measurement end data creation step, the detected measurement end is adopted as the position of the bead end, and the measurement end detects In the second case, the approximate end identified by the approximate end calculating step is adopted as the position of the bead end, and the bead end adopted in the first case and the second case The method may further include a bead end specifying step of specifying the position of the bead end along the longitudinal direction of the weld bead by connecting the positions of.

  Further, after the approximate end calculation step, an approximate end redetection step is further performed, and the measurement width in the workpiece shape detection step including the approximate end along the longitudinal direction of the approximate end is greater than the measurement width A measurement area having a narrow predetermined width is set, and in the measurement area, the position of the rise is detected by detecting again the position of the rise of the weld bead along the direction intersecting the longitudinal direction of the weld bead. The remeasurement end may be detected to replace the approximate end by the remeasurement end, and the position of the bead end may be specified.

  In the first case where the remeasurement end is detected in the approximate end redetection step, the detected remeasurement end is adopted as the position of the bead end, and the remeasurement end is detected. In the second case where no part is detected, the data of the approximate end or the remeasurement end specified by the approximate end calculating step is approximated to a straight line or a curve along the longitudinal direction of the weld bead Thus, the re-approximated end obtained by interpolating the data of the re-measured end is adopted as the position of the bead end, and the position of the bead end adopted in the first case and the second case is adopted. It is preferable to further include a bead end specifying step of specifying the position of the bead end along the longitudinal direction of the weld bead by joining together.

  In addition, it is preferable to further include a weld bead size evaluation step of evaluating the size of the surface shape of the weld bead based on the data of the position of the bead end.

  Further, the detection means does not sweep the band-shaped laser beam in the welding bead in the direction intersecting the longitudinal direction of the welding bead, and the longitudinal direction of the band extends in the direction intersecting the longitudinal direction of the welding bead. It is preferable to detect the position of the bead end of the weld bead by using the reflected light generated by irradiating it along at one time.

  The workpiece may be weld-welded on a step portion provided between a plurality of plate members to form the weld bead.

  On the other hand, the apparatus for evaluating the appearance of a weld bead according to the present invention is a laser displacement meter as the detection means for irradiating a laser beam onto the workpiece on which the weld bead is formed to measure the distance to the workpiece surface. Laser displacement gauge scanning means for relatively displacing the laser displacement gauge along the longitudinal direction of the weld bead by a distance sensor, and information processing means for performing information processing on the measurement result obtained by the laser displacement gauge; The gist of the present invention is to carry out the above-mentioned weld bead appearance evaluation method.

  In the method of evaluating the appearance of the weld bead according to the invention, the measurement end is detected from the information of the surface shape of the work detected along the longitudinal direction of the weld bead, and the data of the measurement end is in the longitudinal direction of the weld bead After plotting along the straight line or curve, the position of the bead end is specified by calculating the approximate end which is interpolated between the measurement end data along the longitudinal direction of the weld bead. Therefore, the surface of the workpiece obtained by the detection means partially along the longitudinal direction of the weld bead due to the gradual change in shape of the position of the bead end portion and the base material, etc. Even when there is a portion where the position of the bead end can not be detected directly from the information of the shape, the position of the bead end can be specified by interpolation. Thereby, the position of the bead end can be continuously estimated and evaluated along the longitudinal direction of the weld bead. In addition, even if the false detection occurs locally for the position of the bead end due to factors such as the presence of rising structures other than the bead end such as spatter, etc., approximation to a straight line or a curve is performed. This makes it possible to reduce the contribution of those false detections, and to evaluate the position of the bead end with high accuracy over the entire area in the longitudinal direction of the weld bead.

  Here, in the measurement end data creation step, the height of the weld bead in the work is differentiated along the direction intersecting the longitudinal direction of the weld bead, and the position at which the absolute value of the differential value becomes a predetermined threshold or more In the case where it is regarded as the measurement end, since the rising structure can be sensitively detected by differentiation, the bead end has high sensitivity even when the shape change between the position of the bead end and the base material is gentle. The position of the department can be evaluated.

  In the first case where the measurement end is detected in the measurement end data creation step, the detected measurement end is adopted as the position of the bead end, and the measurement end is not detected in the second case. The weld bead is adopted by adopting the approximate end specified by the approximate end calculation step as the position of the bead end and connecting the positions of the bead end adopted in the first case and the second case. In the case of further including a bead end specifying step for specifying the position of the bead end along the longitudinal direction, the measurement condition in the detection means may vary, or the shape change of the workpiece may be gradual. Even if there are places where the measurement end is not detected, the position of the bead end of these places is adopted by adopting the approximate end specified by the approximate end calculation step as the position of the bead end. It can be estimated. Thereby, even if there is a place where the bead end can not be detected by the detection means, the position of the bead end can be continuously evaluated along the longitudinal direction of the weld bead.

  In addition, after the approximate end calculation step, the approximate end redetection step is further performed, and a predetermined width narrower than the measurement width in the workpiece shape detection step including the approximate end along the longitudinal direction of the approximate end The area is set, and the position of the rising is detected by detecting the position of the rising of the weld bead again by the detecting means along the direction crossing the longitudinal direction of the weld bead in the measurement area, and the re-measurement end Then, when the approximate end is replaced by the measurement result of the re-measurement end and the position of the bead end is specified, the position of the bead end can be detected with higher detection accuracy. This is because, in the workpiece shape detection step, the measurement width needs to be set wider because the uncertainty of the position of the bead end is high, but once the bead end can be detected, the workpiece shape detection step It is possible to set a predetermined width narrower than the measurement width at which measurement was performed and to perform measurement by the detection means. As a result, since information on the surface shape of the workpiece outside the narrowly set measurement area is not detected at the time of measurement of the remeasurement end, rising of a convex structure such as spatter formed outside the narrow measurement area is detected. There will be no false detection as the position of the bead end. Thus, the detection accuracy of the position of the bead end can be enhanced as compared to the case where the remeasurement is not performed with the measurement area narrowed. Further, by narrowing the measurement width, it becomes easy to increase the accuracy of the measurement itself by the detection means that detects the position of the bead end by the reflected light generated by irradiating the weld bead with light.

  In the first case where the remeasurement end is detected in the approximate end redetection step, the detected remeasurement end is adopted as the position of the bead end, and the remeasurement end is not detected. In the second case, of the data of the remeasurement end by approximating the data of the approximation end or remeasurement end specified by the approximation end calculation step into a straight line or a curve along the longitudinal direction of the weld bead. The reapproximated reapproximated end is adopted as the position of the bead end, and by connecting the positions of the bead end adopted in the first case and the second case, the longitudinal direction of the weld bead is obtained. In the case of further including a bead end specifying step for specifying the position of the bead end, the measurement end has a variation in measurement conditions in the detection means, a gradual change in the shape of the work, etc. Not detected Even if There exist, by employing the approximate end it was identified by approximate end calculation step, or re-approximated ends as the position of the bead edge, can estimate the position of the bead ends of those places. Thereby, even if there is a place where the bead end can not be detected by the detection means, the position of the bead end can be continuously evaluated along the longitudinal direction of the weld bead.

  In addition, in the case of further including a weld bead size evaluation step for evaluating the dimensions of the surface shape of the weld bead based on the data of the specified bead end position, the data of the specified bead end is used as a reference. By means of this, dimensional evaluation of the weld bead can be carried out with high precision, continuously along the longitudinal direction. This enables accurate dimension evaluation of the surface shape of the weld bead.

  In addition, the detection means irradiates at once along the direction in which the longitudinal direction of the strip intersects the longitudinal direction of the weld bead without sweeping the laser beam of the strip across the weld bead in the direction intersecting the longitudinal direction of the weld bead. In the case of detecting the position of the bead end of the weld bead using the reflected light that is generated, the laser beam is swept in the direction intersecting the longitudinal direction of the weld bead by irradiating a band-like laser beam at a time. The time to detect the information on the surface shape of the workpiece can be shortened as compared to the case where the irradiation is performed. Thereby, the detection time of the position of a bead end part can be shortened.

  When the weld bead is formed by build-up welding on the step portion provided between the plurality of plate members, the shape change between the weld bead and the plurality of plate members is gradual. In many cases, it is a gradual work of shape change with almost no step between the bead end and the plate material corresponding to the upper side of the step, but using the method as described above, detection is made due to the looseness of the shape change. Measures the continuity in the longitudinal direction of the weld bead in the evaluation of the position of the bead end even if the position of the bead end can not be detected directly or the measurement measurement is partially incorrect it can.

  On the other hand, according to the weld bead appearance evaluation apparatus according to the invention, the position of the bead end can be continuously evaluated along the longitudinal direction of the weld bead with a simple configuration. Thereby, even in the case of a workpiece whose shape change is gradual, continuity in the longitudinal direction of the weld bead can be secured in the evaluation of the position of the bead end.

It is an external view which shows the external appearance evaluation apparatus of the weld bead of one Embodiment of this invention. (A) It is the sectional view on the AA line of FIG. 1 which shows the workpiece made into the object of appearance evaluation. (B) It is an enlarged view of the dotted-line rectangular part of (a). It is a flow figure showing an example of a method of pinpointing a position of a bead end. (A) It is a schematic diagram explaining a workpiece | work shape detection step. (B) It is a schematic diagram explaining distribution of the height of the surface of a workpiece | work. It is a measurement example of the data which differentiated the height of the surface of a work and expressed two-dimensionally. It is a schematic diagram explaining measurement end part data creation step. It is a schematic diagram explaining calculation of the approximate straight line in an approximate end calculation step. It is a schematic diagram explaining calculation of the distance of the measurement edge part and an approximate straight line in an approximate end redetection step. (A) It is a schematic diagram explaining the setting of the measurement area in an approximate edge part re-detection step. (B) It is a schematic diagram explaining calculation of the redetection in the measurement area, and a re-approximation straight line. (A) It is sectional drawing of the workpiece | work which shows leg length and bead height of a welding bead. (B) It is a flowchart which shows the calculation method of leg length and bead height of (a). (A) It is sectional drawing of the workpiece | work which shows the excess buildup width of a welding bead. (B) It is a flowchart which shows the calculation method of the extra-embedded width of (a).

  Hereinafter, a method and an apparatus for evaluating the appearance of a weld bead according to an embodiment of the present invention will be described with reference to the drawings. The weld bead appearance evaluation method according to an embodiment of the present invention can be performed using the weld bead appearance evaluation apparatus according to an embodiment of the present invention.

[Configuration of Appearance Evaluation Device]
First, the configuration of an appearance evaluation apparatus 1 according to an embodiment of the present invention will be described. FIG. 1 is an external view showing a weld bead appearance evaluation apparatus according to an embodiment of the present invention.

  As shown in FIG. 1, the appearance evaluation apparatus 1 includes a laser displacement meter 2 as a detection unit, a robot 3 as a laser displacement meter scanning unit, and a computer 4 as an information processing unit.

  The laser displacement meter 2 is a detection means for detecting the surface shape of the workpiece 5 by detecting the reflected light generated by irradiating the surface of the workpiece 5 on which the weld bead 51 is formed with the laser light 21. The laser displacement meter 2 is provided with a light source for irradiating the laser beam 21 and a detector for detecting the reflected light from the workpiece 5, and the workpiece 5 on which the welding bead 51 is formed is irradiated with the laser beam 21. The distance to each position on the surface of the above is measured, and a known laser displacement gauge can be used. Here, it is assumed that an elongated weld bead 51 is formed on the surface of a metal material as the work 5, the direction intersecting the longitudinal direction of the weld bead 51 is X direction, and the longitudinal direction of the weld bead 51 is Y direction I assume.

  The laser displacement meter 2 irradiates the weld bead 51 with the strip-like laser beam 21 at one time so that the strip-like longitudinal direction is along the X direction of the weld bead 51 without sweeping the strip in the X direction of the weld bead 51. . And the distribution of the height along the X direction of the welding bead 51 is detected by detecting the strip | belt-shaped reflected light which generate | occur | produces at once. The laser displacement meter 2 is controlled by the computer 4 via the communication line 9 b and inputs the measured data to the computer 4.

  In addition, the robot 3 relatively displaces the laser displacement meter 2 along the Y direction of the welding bead 51. Furthermore, the computer 4 controls the position of the laser displacement meter 2 with respect to the weld bead 51 by controlling the movement of the robot 3 via the communication line 9 a.

  The computer 4 controls the laser displacement meter 2 and the robot 3 as described above, and processes surface shape data of the weld bead 51 measured by the laser displacement meter 2. As a specific data processing, the data obtained by the laser displacement meter 2 can be arithmetically processed to evaluate the position of the bead end 51 a of the weld bead 51 described later. Moreover, the shape of the weld bead 51 can be evaluated based on the information of the position of the bead end 51a evaluated.

  Next, the operation and control of the appearance evaluation apparatus 1 will be described. The external appearance evaluation apparatus 1 irradiates the weld bead 51 with the laser beam 21 at a certain Y-direction position on the weld bead 51 to form the surface shape of the work 5 including the weld bead 51 along the X direction of the weld bead 51. measure. The data obtained by the measurement is sent to the computer 4 via the communication line 9b.

  Next, the robot 3 moves the laser displacement meter 2 along the Y direction of the welding bead 51 by a predetermined distance. Thereafter, by irradiating the weld bead 51 with the laser beam 21 again, the surface shape of the work 5 including the weld bead 51 along the X direction of the weld bead 51 is measured. The data obtained by the measurement is sent to the computer 4.

  Information on the surface shape of the work 5 including the weld bead 51 in the X direction of the weld bead 51 is acquired along the Y direction of the weld bead 51 at predetermined intervals by repeating the above operation a predetermined number of times. As described above, data on the distribution of heights on the surface of the workpiece 5 including the weld bead 51 can be obtained in the XY plane.

[Work shape]
The work 5 to be subjected to the appearance evaluation of the weld bead 51 may be any work as long as it has the weld bead 51 on the surface, but the weld bead 51 is formed in the step portion as an example The work 5 will be described. Fig.2 (a) is the sectional view on the AA line of FIG. 1 which shows the workpiece made into the object of appearance evaluation. Moreover, FIG.2 (b) is an enlarged view of the dotted-line rectangular part of (a).

  As shown in FIG. 2, the work 5 is weld-welded to a step portion 54 provided between the upper plate 52 and the lower plate 53 so as to cross the surface direction of the upper plate 52 and the lower plate 53. Thus, the weld bead 51 is formed. Here, flat plates having straight edges are assumed as the upper plate 52 and the lower plate 53. On the surface of the upper plate 52, a bead end 51a which is an end of the rising 51b of the weld bead 51 is formed. Weld bead 51 has a smaller height 51b of bead end 51a than the height of the rise of weld bead 51 on lower plate 53 of stepped portion 54, and there is no step between the plate members on both sides. It tends to be smaller than the rising height of the weld bead. Therefore, the shape change between the bead end 51 a and the upper plate 52 is gradual.

[Appearance evaluation method]
(Overview)
Next, an outline of the method for evaluating the appearance of the weld bead 51 according to the embodiment of the present invention will be described. This evaluation method can be performed using the appearance evaluation apparatus 1 described above. FIG. 3 is a flow chart showing an example of a method of specifying the position of the bead end.

  As shown in FIG. 3, the method of evaluating the appearance of the weld bead 51 according to the embodiment of the present invention includes (1) work shape detection step, (2) measurement end portion data creation step, and (3) approximate end portion calculation step The position of the bead end 51a is evaluated over a predetermined range in the Y direction, for example, over the entire length of the weld bead 51. Furthermore, after the (3) approximate end calculation step, (4) the approximate end redetection step may be performed. In addition, after (3) the approximate end calculation step or after (4) the approximate end redetection step, (5) the bead end identification step may be performed. Here, in FIG. 3, an embodiment is adopted in which (3) approximate end calculation step, (4) approximate end redetection step, and (5) bead end identification step are sequentially performed.

  (1) In the workpiece shape detection step, the information on the surface shape of the workpiece 5 including the weld bead 51 in the X direction shown in FIG. 1 is measured by the laser displacement meter 2 by measuring the distance to each position on the surface of the workpiece 5 , Over a predetermined range in the Y direction.

  (2) Measurement end portion data creation step processes data of surface shape information of the work 5 by the computer 4 and (1) of the weld bead 51 at each X position measured in the work shape detection step The position of the standup 51 b is detected and plotted along the Y direction of the weld bead 51.

  (3) In the approximate end calculation step, the computer 4 approximates the measurement end data plotted in the (2) measurement end data creation step to a straight line or a curve along the Y direction of the weld bead 51. Thus, (2) in the measurement end data creation step, the approximate end obtained by interpolating between the data of the measurement end discretely plotted along the Y direction of the weld bead 51 is continuously calculated. Even if the approximate end obtained here is adopted as the evaluation result of the position of the bead end 51a, the process may further proceed to (4) approximate end re-detection step or (5) bead end identification step.

  (4) In the approximate end redetection step, the computer 4 calculates the X direction of the weld bead 51 along the Y direction of the approximate end, including the approximate end calculated in the (3) approximate end calculation step. Set a measurement area of a predetermined width along the Here, the predetermined width is (1) a width narrower than the measurement width in the workpiece shape detection step. Then, within the set measurement area, the laser displacement meter 2 irradiates the laser beam 21 again along the X direction of the weld bead 51 to measure the distance to each position on the surface of the workpiece 5. Then, the position of the rising portion 51b of the weld bead 51 is detected again, and the approximate end portion is replaced by the remeasurement end portion, and the position of the bead end portion 51a is specified. Furthermore, if necessary, the re-approximated end is continuously calculated by approximating the data of the re-measured end to a straight line or a curve along the Y direction of the weld bead 51.

  (5) In the bead end specifying step, the computer 4 estimates (2) the measurement end estimated from the actual measurement result in the measurement end data creating step, or (4) the approximate end redetection step from the actual measurement result And the position estimated as the approximate end in the approximate end calculation step or (4) the position estimated as the approximate end in the approximate end redetection step. By combining, the position of the bead end 51a is continuously evaluated along the Y direction.

  When the shape change of the position of the bead end 51a and the upper plate 52 and the lower plate 53 is gradual as shown in FIG. 2 by using the appearance evaluation method of the weld bead 51 of one embodiment of the present invention Etc. by irradiating the laser beam 21 partially along the Y direction of the weld bead 51 and measuring the distance to each position on the surface of the work 5, a position where the position of the bead end 51a can not be detected or Even if there is a place where the detection can not be accurately performed, the position of the bead end 51a can be continuously evaluated along the Y direction of the weld bead 51 including such a place. Also, even if a false detection occurs due to a structure other than weld bead 51, such as spatter, the position of bead end 51a continuously along the Y direction of weld bead 51 including such a location. It can be evaluated, and it can be reduced that structures other than those weld beads 51 contribute as a detection error to the detection result of the bead end 51a.

  Next, (1) work shape detection step, (2) measurement end portion data creation step, (3) approximate end portion calculation step, (4) approximate end portion redetection step, and (5) bead end portion identification step The details of each will be described.

(1) Workpiece Shape Detection Step FIG. 4A is a schematic view illustrating the workpiece shape detection step. FIG. 4B is a schematic view for explaining the distribution of the height of the surface of the workpiece obtained by the workpiece shape detection step.

  (1) In the workpiece shape detection step, information on the surface shapes W1, W2, W3,... Wn of the workpiece 5 including the weld bead 51 along the X direction of the weld bead 51 described in FIG. The laser beam 21 is irradiated along the Y direction of the weld bead 51 at predetermined intervals to measure the distances to the respective positions on the surface of the work 5. Thereby, as schematically described in FIG. 4B, information on the height distribution on the surface of the workpiece 5 can be obtained two-dimensionally in the XY plane. Here, the measurement width D1 along the X direction of the surface shapes W1, W2, W3,... Wn is a laser displacement meter in consideration of the formation position of the weld bead 51 and the measurement position by the laser displacement meter 2. The welding bead 51 is set to be wider so as to be included in the measurement range of 2 with a margin.

(2) Measurement End Data Creation Step In this step, information on the position of the bead end 51a is extracted from the information on the height distribution on the surface of the workpiece 5 obtained in the above (1) workpiece shape detection step. Specifically, first, information on height distributions W1, W2, W3,... Wn is differentiated along the X direction. FIG. 5 is a measurement example of data two-dimensionally expressed by differentiating the height of the surface of the workpiece. In addition, the contrast of FIG. 5 is adjusted in order to clarify description, and emphasizes the brightness of the part of bead end 51a. FIG. 6 is a schematic view for explaining the result obtained by detecting the position of the bead end 51 a based on the differential image as shown in FIG. 5 in the measurement end data creation step. Here, black circles and hatched circles in FIGS. 7, 8 and 9 described later in FIG. 6 and in FIGS. 7, 8 and 9 indicate places detected as the positions of the bead end 51a, and white circles indicate that the bead end 51a is actually Although it exists, in each step, the position is not detected. Moreover, the dashed-dotted line R shows the position of the actual bead edge part 51a currently formed in the workpiece | work 5. As shown in FIG.

  (2) In the measurement end portion data creation step, in the image showing the height distribution of the surface of the work 5 described in FIG. 4B along the X direction of the weld bead 51, the height Z0 of the weld bead 51 Is differentiated from the area where the weld bead 51 is not formed toward the area where the weld bead 51 is formed. In the example described here, as shown by an arrow X1 illustrated in FIG. 4B, from the side of the upper plate 52 having a high height Z0, through the region where the weld bead 51 is formed, the height height Z0 is Differentiate toward the lower lower plate 53 side. For differentiation, a known differential method for two-dimensional data such as a Sobel filter can be used. An example of a two-dimensional expression of the differential result based on the actual measurement is shown in FIG. Then, the position where the absolute value of the differential value is equal to or more than a predetermined threshold value is regarded as the position of the rising 51 b of the weld bead 51 at each Y direction position, and is recorded as the position of the measurement end S. Thus, as described in FIG. 6, the measurement end S is detected as the position of the bead end 51a. Thereafter, the position of the measurement end S is plotted along the Y direction of the weld bead 51. Here, the measurement end S is the position of the bead end 51a detected along the X direction of the weld bead 51, and does not necessarily coincide with the actual position of the bead end 51a, and the position deviation And may include missing data points.

  In the differential image of FIG. 5, the darkly displayed portion is a smooth surface with almost no difference in shape of the surface of the work 5, and the brightly displayed portion is a portion where a standup is present on the surface of the work 5 The higher the lightness, the larger the rising slope of the surface of the work 5. Bright spots are discretely observed along the Y direction (longitudinal direction of the image) at the position on the upper plate 52 side of the weld bead 51 in FIG. 5 and these correspond to the measurement end S at which they are detected. However, along the Y direction, there are places where the bright spots are not observed. Those locations are undetectable locations B where the measurement end could not be detected. In the undetectable portion B, as shown in FIG. 2, the shape change between the position of the bead end 51a and the upper plate 52 is gradual, and there is almost no difference in the shape between the position of the bead end 51a and the upper plate 52 Or when the height of the surface of the work 5 is differentiated because the conditions when measuring the distance to each position on the surface of the work 5 by irradiating the laser light 21 with the laser displacement meter 2 are unstable, etc. In addition, since the differential value more than the predetermined threshold was not detected, the data of the measurement end S was not recorded.

  N shown in FIG. 6 is a non-detection point where the measurement end S is not detected in (2) measurement end data creation step despite the fact that the bead end 51a actually exists, and FIG. Corresponds to the undetectable point B. Further, P detected as the measurement end S3 is largely separated in the X direction from the position of the other measurement end S in the X direction, and is caused by the uneven structure other than the weld bead 51, for example, the surface of the work 5 It is inferred that it originates in the spatter etc. which adhered to. Thereby, as shown by the dotted line in FIG. 6, the measurement end S3 is localized along the X direction more than the positions of the measurement end S1 and the measurement end S2 adjacent to the Y direction and the actual bead end 51a. It gives a detection result such that the weld bead 51 is formed as a shape projecting to the above.

(3) Approximate Edge Calculation Step In this step, (2) the approximate edge is calculated based on the data of the measurement edge S obtained in the measurement edge data creation step. FIG. 7 is a schematic diagram for explaining the calculation of the approximate straight line in the (3) approximate end calculation step.

  (3) The approximate end calculation step approximates the data of the measurement end S detected in (2) measurement end data creation step to a straight line along the Y direction of the weld bead 51, as shown in FIG. Then, along the Y direction of the weld bead 51, an approximate straight line K1, which is an approximate end, is calculated. As a method of approximating to a straight line, a known method such as the least squares method may be used. Here, since the upper plate 52 and the lower plate 53 have linear edges, and a substantially linear weld bead 51 is formed on the step 54 of the edges, an approximation to a straight line is adopted. However, depending on the shape of the edge of the base material forming the weld bead 51 or the shape of the weld bead 51, it may be approximated to a curve having an arbitrary functional shape.

  After the (3) approximate end calculation step, it is preferable to proceed to the next (4) approximate end redetection step or (5) bead end identification step. However, when the steps (4) and (5) are not performed, the approximate straight line K1 may be used as the evaluation result of the bead end 51a. That is, the approximate straight line K1 may be regarded as the position at which the bead end 51a is formed, and may be appropriately used for evaluation of the dimensions (leg length, height, width of extra bulge, etc.) of each part of the weld bead 51.

(4) Approximate end redetection step In this step, the position of the bead end 51a evaluated as the approximate straight line K1 in the above steps (1) to (3) is remeasured using the laser displacement meter 2. To evaluate more accurately. (4) The approximate end redetection step can be implemented by the steps (a) to (e) as follows.

  FIG. 8 is a schematic view for explaining calculation of the distance between the measurement end and the approximate straight line in (4) approximate end redetection step. FIG. 9A is a schematic view for explaining setting of the measurement area in (4) approximate end redetection step. FIG. 9B is a schematic view for explaining redetection in the measurement area and calculation of a re-approximation straight line.

(A) Calculation of the distance between the measurement end and the approximate straight line (4) In the approximate end redetection step, first, the measurement end S in FIG. 7 is prepared for remeasurement using the laser displacement meter 2. The data of approximate straight line K1 are used to calculate the coordinates of each measurement end S with respect to approximate straight line K1 along the X direction of weld bead 51, as shown in FIG. Specifically, a distance LS between each measurement end S and the approximate straight line K1 is calculated along the X direction of the weld bead 51 with respect to the approximate straight line K1. By this, preparation for setting a measurement area E of FIG. 9A described later is performed.

(B) Setting of measurement area Next, as shown in FIG. 9A, along the Y direction of the approximate straight line K1, including the approximate straight line K1, (1) the measurement width D1 in the workpiece shape detection step (see FIG. A measurement area E having a measurement width D2 narrower than 4) (a) is set as a range in which remeasurement by the laser displacement meter 2 is performed. Here, the measurement width D2 sufficiently includes the width in the X direction of the weld bead 51, using the data of the distance LS between the measurement end S calculated in step (a) and the approximate straight line K1, And (1) It is set narrower than the measurement width D1 in the workpiece shape detection step. The measurement width D1 was set wider in order to include the welding bead 51 with a margin in the measurement range of the laser displacement meter 2, but the measurement width has already been measured in the steps (1) to (3) and (a). Since the position of the weld bead 51 in D1 is specified, the measurement width D2 smaller than the measurement width D1 can be set so that the weld bead 51 is surely included in the range. Due to the smallness of the measurement width D2, the uneven structure other than the weld bead 51 such as the sputter P is less likely to enter the measurement area E than when measuring in the measurement width D1.

(C) Re-detection in the measurement area Next, as shown in FIG. 9B, within the range of the measurement area E, again the surface shape of the work 5 including the weld bead 51 in the X direction of the weld bead 51 Information is detected along the Y direction of the weld bead 51 by the laser displacement meter 2 shown in FIG. As a result, an image of the height distribution of the surface of the workpiece which is narrower in the range in the X direction than in FIG. 4B is obtained. Next, (2) as in the measurement end portion data creation step, the welding bead 51 at each position is differentiated by differentiating the welding bead 51 along the X direction so that the absolute value of the differential value is equal to or greater than a predetermined threshold value. It is regarded as the position of the rising edge 51b of and recorded as the re-measurement end T. As a result, as shown in FIG. 9B, the remeasurement end T is detected as the position of the bead end 51a, and is plotted along the Y direction of the weld bead 51. In this remeasurement, not only the measurement width but also the conditions for measurement by the laser displacement meter 2 may be changed from (1) workpiece shape detection step. For example, if using the laser displacement meter 2 in such a form that the measurement accuracy at each X direction position in the measurement width can be improved by narrowing the measurement width, the measurement conditions should be changed as such. Conceivable.

  Here, while the measurement end S is (1) detected based on the result of measuring the height distribution of the surface of the work 5 in the measurement width D1 in the work shape detection step, re-measurement is performed. The end T is detected based on the result of remeasuring the height distribution of the surface of the work 5 in the measurement width D2 narrower than the measurement width D1 in step (c) of the (4) approximate end redetection step. It is (2) In the measurement end data creation step, the sputter P is erroneously detected as the measurement end S, but in the redetection step, the measurement width D2 is set to a narrow area not including the sputter P. Corresponding to the above, the re-measurement end T does not include the detection result due to the sputter P. The positions of the measurement end S and the re-measurement end T at each Y-direction position do not necessarily coincide with each other except at a position where a structure other than the weld bead 51 such as the sputter P is formed. For example, when the measurement conditions are changed from (1) workpiece shape detection step, etc., the remeasurement end T can be obtained as a position closer to the actual position of the weld bead 51 than the measurement end S. . A point M indicated by a white circle in FIG. 9B is a non-detection point at which the re-measurement end T is not detected even in the re-measurement at the measurement width D2 within the range of the measurement area E; Although it does not correspond to the non-detection part N which generate | occur | produced at the step, in the example demonstrated in FIG. 6, it corresponds.

(D) Calculation of Re-approximated End Next, based on the information on the re-measurement end T obtained in the step (c), the re-approximated end is calculated. That is, the data of the remeasurement end T obtained above is taken along the Y direction of the weld bead 51 in the same manner as the data of the measurement end S is obtained in the (3) approximate end calculation step. By approximating to a straight line (or a curve), a re-approximated straight portion K2 which is a re-approximated end is calculated along the Y direction of the weld bead 51. When the necessity of recalculating the re-approximated straight line K2 is low, for example, when the positions of the re-measurement end T and the measurement end S are substantially the same, the calculation is performed in the (3) approximate end calculation step. The approximate straight line K1 may be adopted as the re-approximated straight line K2 as it is.

  After the (4) approximate end redetection step, it is preferable to proceed to the next (5) bead end identification step. However, when the (5) bead end identification step is not performed, the re-approximated straight line K2 may be used as the evaluation result of the bead end 51a. That is, the re-approximated straight line K2 may be regarded as the position where the bead end 51a is formed, and may be appropriately used for evaluation of the bead size and the like.

(5) Bead end identification step (4) Computer after approximate end redetection step or (4) approximate end redetection step if omitted (3) approximate end calculation step Perform step (5) bead end identification step according to 4. Here, the data of the Y-direction position (in the first case) where the position of the bead end 51a could be detected by measurement by the measurement of the laser displacement meter 2 and the measurement of the bead end 51a by the measurement of the laser displacement meter 2 The data of the Y direction position (second case) where the position could not be detected by measurement is connected to specify the position of the bead end 51a.

  FIG. 9B shows the case where (5) bead end identification step is executed after detection of the re-measurement end T and calculation of the re-approximation straight line K2 in (4) approximate end redetection step. Show. Specifically, in the measurement area E in the (4) approximate end redetection step, at the Y direction position at which the remeasurement end T is detected, the detected remeasurement end T is the position of the bead end 51a. Y-direction position where no re-measurement end T was detected (the position that was not the target of discrete measurement by laser displacement meter 2, and the target of measurement, but no detection data was obtained In the case where both non-detection points M are included, (4) the re-approximated straight line K2 detected by the approximate end re-detection step is adopted as the position of the bead end 51a, and they are joined together. It evaluates as a position of bead end 51a continued in the Y direction. As such, the evaluation result continuous in the Y direction obtained by the synthesis may be regarded as the position where the bead end 51a is formed, and may be appropriately used for evaluation of the bead size and the like.

  (4) When the approximate end re-detection step is not performed, the measurement end S is used instead of the re-measurement end T, and the approximate straight line K1 is used instead of the re-approximated straight line K2, as described above. In addition, the position of the bead end 51a continuous in the Y direction of the weld bead 51 can be evaluated.

(Characteristics of appearance evaluation method)
The appearance evaluation method of the weld bead 51 of the present invention includes: (1) Workpiece shape detection step, the surface shape W1 of the workpiece 5 along the Y direction of the weld bead 51 over the measurement width D1 along the X direction of the weld bead 51; The information of W2, W3, ... Wn is acquired, and (2) measurement end portion data creation step detects the data of the measurement end portion S and plots it along the Y direction of the weld bead 51, 3) In the approximate end calculation step, approximate straight line K1 is calculated by approximating data of measurement end S along a Y direction of weld bead 51 to a straight line or a curve. (3) In the Y direction of the weld bead 51, the shape change of the position of the bead end 51a and the upper plate 52 and the lower plate 53 is gradual by including an approximation step such as an approximate end calculation step. Partly along a part where the position of the bead end 51a can not be detected from the information of the surface shape W1, W2, W3, ... Wn of the work 5 (non-detection part N) or the position of the detected bead end 51a Even when there is an inaccurate portion (measurement end S3 by spatter P), the position of the bead end 51a can be continuously estimated along the Y direction of the weld bead 51.

  (2) In the measurement end portion data creation step, the height Z0 of the weld bead 51 on the work 5 is differentiated along the X direction of the weld bead 51, and the absolute value of the derivative value is equal to or greater than a predetermined threshold Position is regarded as the measurement end S. In this case, since the rising structure can be sensitively detected by differentiation, the sensitivity of the bead end 51a can be high sensitivity even when the shape change between the position of the bead end 51a and the upper plate 52 is gradual. The position can be evaluated. However, the present invention is not limited to the form in which differentiation is performed, as long as the rising 51 b of the height Z0 can be detected. For example, when the rising 51b of the weld bead 51 is steep, etc., the height Z0 may be analyzed by using the data of the height distribution as shown in FIG. 4 (b) as it is without differentiation.

  (3) The approximate end calculation step: (2) The data of the measurement end S detected in the measurement end data creation step is approximated to a straight line (or a curve) to obtain the bead end 51 a The measurement edge S locally along the Y direction of the weld bead 51 derived from the gradual change in shape between the position and the upper plate 52, the fluctuation of the measurement condition of the laser displacement meter 2, etc. Even if there are places where it can not be detected, the position of the bead end 51a can be continuously evaluated along the Y direction, including these places. The position of the bead end 51a can also be estimated, including the Y-direction position where measurement is not performed, which corresponds to the position between discrete measurements by the laser displacement meter 2. Furthermore, even if a false detection occurs locally for the position of the bead end 51a due to the presence of a rising structure other than the bead end 51a such as spatter P or the like, the false detection occurs at the bead end It is possible to dilute the contribution given to the detection result of the position of the portion 51a, and to evaluate the position of the bead end 51a continuously and with high accuracy throughout the entire area of the weld bead 51 in the Y direction.

  When performing the (4) approximate end redetection step in addition to the steps (1) to (3), including the approximate straight line K1 along the Y direction of the approximate straight line K1, (1) work In the measurement width D2 narrower than the measurement width D1 in the shape detection step, the measurement by the laser displacement meter 2 is performed again, and the position of the rising 51b of the weld bead 51 is detected again to be the remeasurement end T The position of the end 51a is specified. In this case, the position of the bead end 51a can be detected with higher detection accuracy. Because (1) in the workpiece shape detection step, it is necessary to set the measurement width D1 wider because the uncertainty of the position of the bead end 51a to be detected is high, but once the bead end 51a is detected If it is possible, the measurement width D2 can be set narrower than the measurement width D1. As a result, the information on the surface shape of the work 5 outside the measurement area E defined by the narrow measurement width D2 is not detected, and therefore, other than the weld bead 51 such as the sputter P formed outside the measurement area E The rising of the concavo-convex structure is not erroneously detected as the position of the bead end 51a. As described above, the detection accuracy of the position of the bead end 51a can be enhanced as compared to the case where the narrow measurement width D2 is reset and remeasurement is not performed. Further, by narrowing the measurement width, it becomes easy to increase the measurement accuracy of the laser displacement meter 2 itself which detects the position of the bead end 51a by the reflected light generated by irradiating the weld bead 51 with light.

  (3) Adopting the approximate end K1 obtained in the approximate end calculation step or the re-approximated end K2 obtained in the (4) approximate end redetection step as the evaluation result of the position of the bead end 51a It may be used as a basis for evaluation of dimensions (leg length, height, width of excess buildup, etc.), but (5) Based on measurement by the laser displacement meter 2 by executing the bead end identification step. The information on the detected measurement end S and the re-measurement end T can be effectively used, and the actual position of the bead end 51a can be more accurately evaluated while compensating for the lack and inaccuracies of the detection result. As described above, (5) in the bead end identification step, in the first case, that is, (2) when the measurement end S is detected in the measurement end data creation step, or (4) the approximate end re In the detection step, when the re-measurement end T is detected, the detected measurement end S or the re-measurement end T is adopted as the position of the bead end 51 a. On the other hand, in the second case, that is, when the measurement end S or the re-measurement end T is not detected, (3) the approximate end K1 calculated by the approximate end calculating step or (4) the approximate end The re-approximated end K2 calculated in the detection step is adopted as the position of the bead end 51a. Then, in each case, by combining the adopted measurement end S or re-measurement end T with the approximate end K1 or the re-approximated end K2, the Y-direction bead end 51a of the weld bead 51 is obtained. Locate the location continuously. As described above, by combining the detection result of the position of the bead end 51a based on the measurement and the estimation result of the position of the bead end 51a based on the approximation, the Y-direction position where detection based on the measurement is possible Y can not accurately detect the actual position of the bead end 51a, and at the same time Y can not be detected at the measurement end due to variations in measurement conditions, gentleness of shape change of the work 5, etc. At the directional position, the detection results at other Y-direction positions can be used to estimate the probable position of the bead end 51a. Thereby, in evaluation of the position of bead end 51a, continuity in the Y direction of welding bead 51 and high accuracy can be compatible.

  The workpiece 5 to be detected for the position of the bead end 51 a of the weld bead 51 does not ask a specific type or shape. However, as described above, the workpiece 5 comprises the upper plate 52 and the lower plate 53. In the case where the weld bead 51 is formed by build-up welding with respect to the step portion 54 provided therebetween, the characteristics of the evaluation method according to the above embodiment can be effectively utilized. That is, when the weld bead 51 is formed in such a step portion 54, the shape change between the weld bead 51 and the upper plate 52 is gradual and corresponds to the upper side of the bead end 51a and the step portion 54. It becomes a gradual work 5 of shape change with almost no level difference with the plate 52, and it is difficult to continuously evaluate the accurate position of the bead end 51a along the Y direction by the conventional general bead end detection method In many cases, by using the evaluation method according to the present embodiment as described above, a position where the position of the bead end 51a can not be detected directly or a position where the measurement is incorrect in measurement by the laser displacement meter 2 In the evaluation of the position of the bead end 51a, the continuity in the Y direction of the weld bead 51 can be ensured even if the part E. In the appearance evaluation method, the lower plate side end 51c of the lower plate 53 of the work 5 can be specified in the same manner.

  An apparatus for carrying out the appearance evaluation method according to the embodiment of the present invention is not particularly limited, but the apparatus configuration is simplified by using the appearance evaluation apparatus 1 according to the embodiment of the present invention, The position of the bead end 51 a can be detected continuously along the Y direction of the weld bead 51 with high accuracy.

  For example, as long as the measuring means used for measurement of the position of the bead end 51a can irradiate the light to the work 5 and obtain information on the height Z0 of each part of the work 5 included in the reflected light, what kind of The longitudinal direction of the strip may be in the X direction of the weld bead 51 without sweeping the strip of laser light 21 in the X direction of the weld bead 51 as described above. The laser light 21 is swept and irradiated in the X direction of the weld bead 51 by using a form which irradiates at once at one time and detects the reflected light generated at once, and the reflected light from each part in the X direction The time for detecting the information on the surface shape of the work 5 can be shortened as compared with the case of sequentially detecting X. The convenience in measurement is enhanced.

(Weld bead size evaluation step)
The appearance evaluation method of the weld bead 51 according to the embodiment of the present invention includes (1) work shape detection step, (2) measurement end portion data creation step, (3) approximate end portion calculation step, and further as required (4 ) Based on the data of the position of the bead end 51a, which is performed in the order of the approximate end redetection step and / or (5) bead end identification step, the leg length, height, width of the overhang, etc. are welded The method may further include a welding bead size evaluation step of evaluating the size of each part of the bead 51.

  In order to evaluate the dimensions of the weld bead 51, it is necessary to specify the position of the bead end 51a as a reference. The information on the position of the bead end 51a evaluated in each of the above steps specifies the position of the bead end 51a continuously along the Y direction with high accuracy. It can be highly accurate basic information for evaluation.

  Here, the step of evaluating the weld bead size will be described by taking, as an example, the case of evaluating the leg length and height, and the overfill width as the dimensions of the weld bead 51. The evaluation of the dimensions of the weld bead 51 uses data on the surface shape of the work 5 acquired in the (1) work shape detection step for specifying the bead end 51a as shown in FIG. 4 (b). Can be done.

(A) Calculation of leg length and bead height In the calculation of the leg length L and the bead height H, the leg length L and the bead height H shown in the work 5 of FIG. 10A are shown in FIG. Calculated from a) to (e). Here, as shown in FIG. 10 (a), the leg length L is the length of a line segment ll connecting the bead end 51a and the lower plate side end 51c (the end on the lower plate 53 side of the weld bead 51). It is. Further, the bead height H is the maximum length of the line segment hh perpendicular to the leg length L.

(A) Calculation of leg length of work surface First, at a predetermined position of weld bead 51 in the Y direction, the positions of bead end 51a and lower plate side end 51c specified on the surface of work 5 along the X direction From the data shown, the leg length L which is the distance between the bead end 51a and the lower plate side end 51c is calculated. At this time, the lower plate side end 51c on the lower plate 53 side is the same as the specification of the position of the bead end 51a on the upper plate 52 side, (1) work shape detection step in the appearance evaluation method of the weld bead 51; (2) Measurement end portion data creation step, (3) Approximate end portion calculation step can be performed in this order and identified. (1) The workpiece shape detection step can be used as it is (1) the result of the workpiece shape detection step performed when specifying the position of the bead end 51a without newly performing the workpiece shape detection step. Further, since the rising structure from the lower plate 53 of the lower plate side end 51c is clear as compared with the rising structure from the upper plate 52 of the bead end 51a, (2) differentiation in the measurement end data creation step The operation and (3) the approximate end calculation step may be omitted as appropriate.

(B) Calculation of the leg length of the weld bead in the Y direction Next, the above-described step (a) performed for the predetermined position in the Y direction of the weld bead 51 is performed at a predetermined interval over the entire area in the Y direction. Repeatedly, the leg length L at each Y-direction position is calculated. Thus, the evaluation of the leg length L over the entire area of the weld bead 51 is completed.

(C) Calculation of the length of a line segment perpendicular to the leg length At a predetermined position in the Y direction of the weld bead 51, the bead end 51a on the upper plate 52 side used for calculating the leg length L in step (a) above A line segment hh connecting the line segment ll and the top of the weld bead 51 is set perpendicular to the line segment ll connecting between the lower plate side end 51 c on the lower plate 53 side. Then, the length of the line segment hh is calculated. Here, the position of the top portion of the weld bead 51 is the data of the height distribution of the surface of the work 5 obtained in the above (1) work shape detection step and / or the differential data obtained in the (2) measurement end data creation step It can be estimated using The setting of the line segment hh and the calculation of the length are performed along the line segment ll over the entire range from the bead end 51a to the lower plate side end 51c.

(D) Calculation of bead height The length of the line segment hh which is the largest among the line segments hh perpendicular to the line segment 11 calculated in the whole area of the line segment 11 in the step (c) is calculated. Then, the length of the line segment hh which becomes the maximum is taken as the bead height H.

(E) Calculation of the bead height of the weld bead in the Y direction Next, the above steps (c) and (d) performed for the predetermined position in the Y direction of the weld bead 51 are applied to the entire area in the Y direction. The bead height H at each Y-direction position is calculated repeatedly at predetermined intervals. Thereby, evaluation of bead height H of welding bead 51 is completed.

(B) Calculation of Overfill Width In calculation of the overfill width C, the overfill width C shown in the work 5 of FIG. 11 (a) is calculated by steps (a) and (b) shown in FIG. 11 (b) Do. Here, the extra-filling width C is a length of a line segment connecting the bead end 51a and the lower plate side end 51c along the X direction in FIG.

(A) Calculation of excess buildup width of work surface First, the bead end 51a and the lower plate at the upper plate 52 side specified on the surface of the work 5 along the X direction at a predetermined position of the weld bead 51 in the Y direction From the data of the position of the lower plate side end 51c on the 53 side, it is assumed that the length of a line segment cc parallel to the X direction connecting the bead end 51a of the weld bead 51 and the lower plate side end 51c Calculate C.

(B) Calculation of excess width of weld bead in Y direction Next, the above-mentioned step (a) executed for a predetermined position in weld direction of weld bead 51 is performed for the entire region in Y direction. Repeatedly at intervals, the extra-filling width C at each Y-direction position is calculated. Thus, the evaluation of the overfilling width C of the weld bead 51 is completed.

  The appearance evaluation method of the weld bead 51 according to the embodiment of the present invention further includes a weld bead size evaluation step, whereby the data of the position of the bead end 51a specified in each step of the above (1) to (5) is obtained. The dimensions of each part of the weld bead 51 can be evaluated with high accuracy using this. In addition to the leg length L of the weld bead 51, the bead height H, and the overfilling width C, in the method of evaluating the appearance of the weld bead 51, various parameters related to the shape of the weld bead 51 are obtained. It can be evaluated on the basis of

  As mentioned above, although embodiment and Example of this invention were described in detail, this invention is not limited to the said embodiment and Example, A various change is possible in the range which does not deviate from the summary of this invention. .

1 Appearance evaluation device 2 Laser displacement meter (detection means)
3 Robot (laser displacement gauge scanning means)
4 Computer (information processing means)
5 Workpiece 21 Laser beam 51 Weld bead 51a Bead end 51b Rise 51c Lower plate side end 52 Upper plate (plate material)
53 Lower plate (plate material)
54 Stepped part D1, D2 Measurement width E Measurement area K1 Approximate straight line (approximated end)
K2 reapproximated straight line (reapproximated end)
S Measurement end T Re-measurement end W1, W2, W3, ... Wn Surface shape X direction of work 5 Direction Y crossing the longitudinal direction of weld bead 51 Longitudinal direction Z of weld bead 51 Z high height of weld bead 51 The

Claims (9)

Method of evaluating appearance of weld bead using detection means for detecting the position of bead end which is the end of rising of weld bead formed on the surface of work by irradiating the weld bead with light and generating the reflected light In
The information on the surface shape of the work including the weld bead in the direction intersecting the longitudinal direction of the weld bead is measured by the detection means over the measurement width along the direction intersecting the longitudinal direction of the weld bead. A workpiece shape detection step of detecting along a direction;
Measurement that detects the rising position of the weld bead in the direction intersecting with the longitudinal direction of the weld bead, which is included in the information of the surface shape of the work, as a measurement end, and plots along the longitudinal direction of the weld bead Edge data creation step,
The bead end portion is calculated by calculating the approximate end portion interpolated between the data of the measurement end portions by approximating the plotted data of the measurement end portions into a straight line or a curve along the longitudinal direction of the weld bead. Calculating an appearance of the weld bead, and calculating an approximate end portion of the weld bead.   The measurement end portion data creation step differentiates the height of the weld bead in the work along the direction intersecting the longitudinal direction of the weld bead, and the absolute value of the differential value becomes equal to or more than a predetermined threshold value The method for evaluating the appearance of a weld bead according to claim 1, wherein a position is regarded as the measurement end. In the first case where the measurement end is detected in the measurement end data creation step, the detected measurement end is adopted as the position of the bead end,
In the second case where the measurement end is not detected, the approximate end identified by the approximate end calculating step is adopted as the position of the bead end,
The bead end identification step of specifying the position of the bead end along the longitudinal direction of the weld bead by connecting the positions of the bead end adopted in the first case and the second case The method for evaluating the appearance of a weld bead according to claim 1 or 2, characterized in that After the approximate end calculation step, an approximate end redetection step is further performed, and a predetermined width narrower than the measurement width in the workpiece shape detection step including the approximate end along the longitudinal direction of the approximate end. Set the width measurement area,
In the measurement area, the position of the rising is detected by detecting again the position of the rising of the weld bead along the direction intersecting the longitudinal direction of the weld bead, and the position of the rising is detected to be a remeasurement end. ,
The weld bead appearance evaluation method according to any one of claims 1 to 3, wherein the approximate end is replaced by the re-measurement end, and the position of the bead end is specified. In the first case where the re-measurement end is detected in the approximate end re-detection step, the detected re-measurement end is adopted as the position of the bead end, in the first case.
In the second case where the remeasurement end is not detected, the data of the approximate end identified by the approximate end calculation step or the remeasurement end may be a straight line along the longitudinal direction of the weld bead or Adopting a re-approximation end obtained by interpolating data of the re-measurement end by approximating a curve as a position of the bead end,
The bead end identification step of specifying the position of the bead end along the longitudinal direction of the weld bead by connecting the positions of the bead end adopted in the first case and the second case The method for evaluating the appearance of a weld bead according to claim 4, characterized by comprising:   The welding bead dimension evaluation step of performing dimensional evaluation of the surface shape of the said welding bead based on the data of the position of the said bead end is further provided in any one of Claim 1 to 5 characterized by the above-mentioned. Evaluation method of appearance of weld bead as described.   The detection means does not sweep a band of laser light in the weld bead in a direction intersecting the longitudinal direction of the weld bead, and along the direction in which the longitudinal direction of the band intersects the longitudinal direction of the weld bead The appearance evaluation of the weld bead according to any one of claims 1 to 6, wherein the position of the bead end of the weld bead is detected using reflected light generated by irradiation at one time. Method.   8. The welding bead according to any one of claims 1 to 7, wherein the welding bead is formed by buildup welding on the step portion provided between the plurality of plate members. Evaluation method of appearance of weld bead as described. A laser displacement gauge as the detection means for irradiating the workpiece with the weld bead formed thereon with a laser beam to measure the distance to the workpiece surface;
Laser displacement gauge scanning means for relatively displacing the laser displacement gauge along the longitudinal direction of the weld bead by a distance sensor;
Information processing means for performing information processing on the measurement result obtained by the laser displacement meter;
An apparatus for evaluating the appearance of a weld bead, which implements the method for evaluating the appearance of a weld bead according to any one of claims 1 to 8.