JP2011191161A - Weld zone undercut inspection device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a weld zone undercut inspection device which can easily detect existence and a magnitude of a weld defect caused by undercut of the weld zone. <P>SOLUTION: The weld zone undercut inspection device 1 for detecting undercut generated on a boundary part 220 between a base metal and a weld bead from a sectional outer shape of a part 10 to be inspected, includes: a two-dimensional displacement gage 2 for detecting the shape of the part 10 to be inspected by irradiating the part 10 with a belt-like spread laser light L; a controller 3 for operating the sectional outer shape of the part to be inspected based on detection data; and a display 4 for displaying an operation result; wherein the controller 3 determines a reference line 230 from a base metal line 221 based on the base metal line 221 showing a base metal surface specified by the sectional outer shape and a weld line 225 showing a weld bead surface, and calculates the maximum depth of the weld line relative to a normal direction to the reference line 230. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention is an inspection device for detecting an undercut of a welded portion, and more particularly, a welded portion undercut inspection device that automatically detects the presence and size of a weld defect due to an undercut using a laser beam. About.

  In steel bridges, welding connections are made by combining steel plates to form steel girders and the like. In that case, since there is a possibility that a defect due to undercut may occur on the surface of the weld bead, it is necessary to detect it, and the depth of the undercut must be determined in order to confirm the processing method of the defect. Conventionally, the undercut was confirmed by visual observation of the welding operator, and the depth was measured using a measuring instrument. Under such circumstances, automatic detection of the undercut of the weld bead is desired, and various proposals have been made.

  The following patent document 1 can be mentioned as the example. This document describes an inspection target for a joint where the end edges of plate-shaped base materials are vertically butted and welded. In this inspection device, a cross-sectional profile (cross-sectional outline) of a base material and a weld bead is measured using a three-dimensional laser displacement meter, and a virtual straight line corresponding to the base material surface is extracted and an intersection of the virtual straight lines is specified. Done. And the displacement from a virtual intersection is calculated | required about the arbitrary points on the bead surface, and the quality of the welding state based on the value is determined.

JP 2008-302428 A

By the way, if the operator visually inspected, it took skill to find the undercut and measure the depth, and moreover, errors were likely to occur because the quality was judged in units of 0.1 mm. In this regard, an accurate value can be obtained in the inspection using the inspection apparatus, but there are various configurations.
The present invention is an automatic detection device that employs a method different from the conventional one, and a simple weld undercut inspection that detects the presence and size of a weld defect due to an undercut of the weld. An object is to provide an apparatus.

  A welded portion undercut inspection apparatus according to the present invention is a two-dimensional displacement for detecting a shape of a portion to be inspected by irradiating a strip-shaped laser beam having a welded portion as a portion to be inspected and receiving reflected laser light. A cross section of the inspected part, a controller for calculating the cross-sectional outer shape of the inspected part based on detection data sent from the two-dimensional displacement meter, and a display for displaying the calculation result from the controller An undercut that occurs at the boundary between the base material and the weld bead is detected from the outer shape, and the controller includes a base material line indicating the base material surface specified by the cross-sectional shape and a weld line indicating the weld bead surface. The reference line is obtained from the base material line, and the maximum depth of the weld line is calculated from the reference line with respect to the normal direction relative to the reference line. To.

Further, in the weld undercut inspection device according to the present invention, the controller obtains a reference line from an average value of values in the normal direction for a part of the base material wire, and the weld line located at the boundary portion. It is preferable that the maximum depth be calculated.
Further, the weld undercut inspection device according to the present invention displays the cross-sectional outline, the value of the maximum depth of the undercut portion, and a mark when the value exceeds a predetermined reference value on the display. It is preferable to display.

  Therefore, according to the present invention, it is possible to confirm the confirmation of the undercut and to determine the exact size of the undercut as compared with the inspection visually performed by the operator. Also, based on the base metal line and the weld line, the reference line is obtained from the base metal line, and the maximum depth is calculated in the normal direction with respect to the reference line. .

It is a block diagram which shows embodiment of a welding part undercut inspection apparatus. It is the perspective view which showed the test | inspection condition which irradiated the laser beam to the to-be-inspected part. It is the figure which showed notionally the detection method of the undercut by a welding part undercut inspection apparatus. It is the figure which expanded and displayed the cross-sectional profile of the boundary part, changing an angle.

  Next, an embodiment of a welded undercut inspection device according to the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram showing a welded undercut inspection device. This welded undercut inspection device (hereinafter simply referred to as “inspection device”) 1 includes a sensor head 2 for detecting the shape of the portion to be inspected 10 by a laser beam L, and a controller 3 is connected thereto. . The controller 3 performs arithmetic processing on the detection data sent from the sensor head 2 and is connected to a display 4 for displaying the calculation result.

  In the sensor head 2, the laser light L emitted from the laser diode passes through the light projection lens and is irradiated on the inspected part 10, and the reflected laser light L passes through the light receiving lens and is received by the light receiving element, corresponding to the amount of light received. The charge to be accumulated is taken out for each pixel component. The controller 3 has a microprocessor, controls the output (light emission amount) of the laser diode to the sensor head 2, and calculates the displacement of the inspected part 10 from the signal read by the light receiving element.

  The inspection apparatus 1 measures a cross-sectional profile of the inspected part, and the sensor head 2 forms a band of the laser light L irradiated to the inspected part as shown in FIG. The two-dimensional triangulation method is used. The sensor head 2 diffuses and reflects the laser light L spread in a band shape by the cylindrical lens on the surface of the part to be inspected, and forms an image of the reflected light on the light receiving element. An analog signal from such a sensor head 2 is taken into a controller, amplified by an amplifier, and converted into a digital signal by a conversion means. As a result, a received light image is obtained, a cross-sectional profile is generated by the image processing unit, and this image data is displayed on the display 4.

  Here, FIG. 3 is a diagram conceptually showing an undercut detection method by the inspection apparatus 1. As shown in FIG. 2, the part to be inspected for inspecting the undercut according to the present embodiment abuts the longitudinal steel plate 21 so that the transverse steel plate 22 is orthogonal to each other, and joins the abutting portion of the transverse steel plate 22 by welding. Part 20. The longitudinal direction (joining direction) of the weld bead 25 is taken as the X axis, and the directions along the surfaces of the longitudinal steel plate 21 and the transverse steel plate 22 perpendicular to the X axis are taken as the Y axis and the Z axis, respectively. When the Y-axis and Z-axis directions are defined as the width direction of the weld bead 25, undercuts may occur at both ends in the width direction, so that the position is set as an inspection target. The line displayed in FIG. 3 is a cross-sectional profile obtained by cutting the P portion of FIG. 2 in the width direction, and is a base material wire 221 and a weld line 225 showing the surfaces of the vertical steel plate 21 and the weld bead 25.

  In this case, as indicated by the base metal wire 221 and the weld line 225, an undercut occurs at a position where the angle changes between the vertical steel plate 21 and the weld bead 25, that is, at the boundary portion 220 between the vertical steel plate 21 and the weld bead 25. Therefore, when the cross-sectional profile of the joint portion 20 is generated as described above, in the present embodiment, the first area 31 and the second area as shown by the one-dot chain line in FIG. The area 32 is set, and the depth of the undercut portion 228 is calculated. At this time, the base material wire 221, the boundary portion 220, the first area 31, and the second area 32 are displayed on the display 4.

  Here, FIG. 4 is an enlarged view of the cross-sectional profile of the boundary portion 220 at different angles. First, an average value in the height direction (Z-axis direction) is obtained for the base material wire 221 in the first area 31 from the cross-sectional profile. In this case, as shown in FIG. 2, the base material wire 221 is parallel to the Y-axis direction along the vertical steel plate 21 and is orthogonal to the Z-axis. An average value in the Z-axis direction is calculated for the base material wire 221 in the first area 31, and the value is set as a reference value in the height direction (Z-axis direction). Therefore, a line drawn in parallel with the Y axis in the reference value becomes a reference line 230 indicating the surface of the vertical steel plate 21. Then, the depth of the undercut portion 228 is calculated depending on the distance from the reference line 230.

  In the second area 32, the distance in the normal direction (Z-axis direction) from the reference line 230 to the base metal line 221 and the weld line 225 is calculated based on the cross-sectional profile of the portion. Accordingly, the maximum depth Hmax from the deepest reference line 230 of the undercut portion 228 can be obtained as shown in FIG. The numerical value of the maximum depth Hmax obtained here is displayed on the display 4 together with the cross-sectional profile shown in FIG. Further, in the case of a steel bridge, for example, an undercut depth of up to 0.3 mm is an acceptable value. Therefore, when the maximum depth Hmax of the undercut portion 228 exceeds 0.3 mm, “NG” is displayed on the display 4. "Is displayed.

  Although FIG. 3 and FIG. 4 demonstrated the undercut which arises in the edge part of the Y-axis direction of the weld bead 25 shown in FIG. 2, the undercut which arises in the edge part of the opposite Z-axis direction is measured similarly. That is, although a figure is omitted, a reference line is obtained by an average value in the height direction (Y-axis direction) from the base material line of the horizontal steel plate 22 in the first area by the cross-sectional profile of the boundary portion, and in the second area The undercut depth is calculated from the reference line. Similarly, the display 4 displays a base metal line and a weld line showing the surfaces of the horizontal steel plate 22 and the weld bead 25, a maximum depth Hmax, and the like. Further, the sensor head 2 moves linearly in the X-axis direction along the weld bead 25, and the above-described undercut measurement is repeated during that time.

Therefore, according to the inspection apparatus 1 of the present embodiment, it is possible to confirm a reliable undercut and to determine the exact size of the undercut as compared with the inspection visually performed by the operator, and to exceed the reference depth. If the undercut is displayed as “NG”, the judgment becomes easy.
Also, a method of measuring the distance in the normal direction from the reference line 230 by specifying the first area 31 and the second area 32 as shown in FIG. 3 using the boundary portion between the base material and the weld bead as the inspection location. By adopting, it was possible to make a simple configuration.

  Although the embodiment of the weld undercut inspection device according to the present invention has been described, the present invention is not limited to this, and various modifications can be made without departing from the spirit of the present invention.

DESCRIPTION OF SYMBOLS 1 Welding part undercut inspection apparatus 2 Sensor head 3 Controller 4 Display 10 Inspection part 21 Vertical steel plate 22 Horizontal steel plate 25 Weld bead 220 Boundary part 221 Base material line 225 Welding line 228 Undercut part 230 Reference line L Laser beam

Claims (3)

A two-dimensional displacement meter for detecting a shape of the inspected portion by irradiating a belt-like laser beam having a welded portion as an inspected portion, receiving reflected light, and detection sent from the two-dimensional displacement meter A controller that calculates the cross-sectional outline of the inspected part based on the data, and a display that displays the calculation result from the controller, and from the cross-sectional outline of the inspected part to the boundary portion between the base material and the weld bead In the weld undercut inspection device that detects the undercut that occurs,
The controller obtains a reference line from the base material line based on a base material line indicating a base material surface specified by the cross-sectional outline and a weld line indicating a weld bead surface, and a normal direction relative to the reference line The weld undercut inspection apparatus is characterized in that the maximum depth of the weld line is calculated from the reference line. In the welding part undercut inspection apparatus according to claim 1,
The controller obtains a reference line from an average value in the normal direction for a part of the base metal wire, and calculates the maximum depth of the weld line located at the boundary portion. A welded undercut inspection device characterized by being. In the welded undercut inspection device according to claim 1 or 2,
The weld undercut, wherein the cross-sectional outline, the value of the maximum depth of the undercut portion, and a mark when the value exceeds a predetermined reference value are displayed on the display. Inspection device.

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