JP3860156B2 - Copy welding equipment - Google Patents

Description

  The present invention relates to a novel copy welding apparatus. More specifically, the present invention relates to a technique for image recognition of a groove and performing reliable copying without being affected by the surface state of a workpiece.

  In the profiling welding technique, non-contact profiling sensors are being promoted.

  In particular, Patent Literature 1, Patent Literature 2, Patent Literature 3 and the like disclose a technique for recognizing a groove using image recognition means and copying a welding torch along the recognized groove.

  Each of the techniques disclosed in the above Patent Documents 1 to 3 obtains a light cut image by irradiating a laser slit light so as to cross the groove, and obtains copying information by image processing the light cut image. It is.

  According to the laser slit light irradiation, there is an advantage that the width and depth of the groove can be measured by one image acquisition means, but when the groove is not formed in the groove, for example, when applied to butt welding, A light-cut image cannot be obtained and copying is impossible.

  The one described in Patent Document 4 does not use laser slit light, and starts welding while photographing a fillet welded portion by two thin plates from the front of the welding direction with a CCD camera, and at an appropriate threshold value. Based on the binarized arc light, a rectangular processing area including a welding line is set in front of the arc light, and a scanning line in the direction intersecting the welding line is drawn in the processing area to analyze the luminance on the scanning line. Then, the intersection with the weld line is obtained, and such a process is performed over the entire processing region to detect the weld line.

  However, arc light is a by-product of the arc and molten pool caused by the current voltage as welding conditions, and it is impossible to "control the arc light" or "the arc light is always constant" It can be said that.

JP-A-8-281435

JP 2002-120066 A Japanese Patent Laid-Open No. 2003-1420 JP-A-11-287619

  Therefore, the present invention detects a groove by image processing from an image of a groove area preceding the welding torch without using an optical cutting line by laser slit light, and moves the welding torch based on the detection result. It is an object of the present invention to provide a copying welding apparatus using image processing with high versatility without limiting the types of grooves that can be copied by controlling a line.

In order to solve the above-described problem, the copying welding apparatus according to the present invention acquires an image of a welding torch and a groove preceding the welding torch (hereinafter referred to as “preceding groove region”); Obtained by shielding means for shielding the welding torch against the preceding groove region, left and right drive means for integrally supporting the welding torch, image obtaining means and shielding means and moving in the left-right direction, and the image obtaining means. A positional deviation between the position of the groove in the left-right direction and the position of the welding torch in the left-right direction is detected from the image, and the left-right drive means is driven based on the detection result to determine the position of the groove in the left-right direction and the position of the welding torch. formed Ri and a control means for the position in the lateral direction is controlled so as to coincide, which has a vertical drive means for moving the left and right drive means in the vertical direction, the shielding The stage includes a sensor for detecting a position of the tip part, the tip part contacting the work being movable in a direction in which the tip part is separated from and contacting the work, and the control means is based on the detection result of the sensor. To control the position of the tip of the shielding means, the welding torch, and the image acquisition means so as to maintain a predetermined positional relationship .

Therefore, in the profiling welding apparatus of the present invention, it is possible to follow all kinds of grooves without increasing the size of the entire apparatus, and profiling welding with high accuracy is possible. In addition, an up-and-down scanning sensor that is originally necessary for the copying welding apparatus can be used as the shielding means, and it is not necessary to provide a special shielding means, and the copying welding apparatus can be configured at low cost.

The copying welding apparatus according to the present invention includes a welding torch, image acquisition means for acquiring an image of a groove preceding the welding torch (hereinafter referred to as “preceding groove region”), and a welding torch for the preceding groove region. Shielding means for shielding, a welding drive torch, an image acquisition means and a left and right drive means for integrally moving the shielding means and moving in the left and right direction, and a position of the groove in the horizontal direction from the image acquired by the image acquisition means And the position of the welding torch in the left-right direction is detected, and the left-right drive means is driven based on the detection result so that the position of the groove in the left-right direction matches the position of the welding torch in the left-right direction. Ri formed and a control means for controlling the, which has a vertical drive means for moving the left and right drive means in the vertical direction, the said shielding means tip contacts the workpiece And a sensor that detects the position of the tip portion, and the control means drives the vertical drive means based on the detection result of the sensor, and the shielding means The position control is performed so that the distal end portion of the metal plate, the welding torch, and the image acquisition means maintain a predetermined positional relationship .

Therefore, in the profiling welding apparatus of the present invention, it is possible to follow all kinds of grooves without increasing the size of the entire apparatus, and profiling welding with high accuracy is possible. In addition, an up-and-down scanning sensor that is originally necessary for the copying welding apparatus can be used as the shielding means, and it is not necessary to provide a special shielding means, and the copying welding apparatus can be configured at low cost.

  In the invention described in claim 2, the image acquisition means includes an imaging means and an illuminating means for illuminating the preceding groove area, and the illuminating means is illumination light coaxial with the optical axis of the imaging means. Is configured to illuminate the preceding groove area, it is difficult to produce scattered light on the surface of the preceding groove area, and a high-quality image can be acquired, and as a result, accurate copying can be performed. .

  The best mode for carrying out the copying welding apparatus of the present invention will be described below with reference to the accompanying drawings.

  The profile welding apparatus 10 according to the present invention includes a welding torch 20, an image acquisition means 30 for acquiring an image of a groove preceding the welding torch 20 (hereinafter referred to as "preceding groove area"), and the preceding groove. The shielding means 40 that shields the welding torch from the region, the left and right driving means 50 that integrally supports the welding torch 20, the image acquisition means 30, and the shielding means 40 and moves in the left-right direction, and the image acquisition means. A positional deviation between the position of the groove in the left-right direction and the position of the welding torch in the left-right direction is detected from the acquired image, and the position of the groove in the left-right direction and the welding are driven by driving the left-right driving means based on the detection result. Control means 60 for controlling the position of the torch in the left-right direction to coincide with each other, and vertical drive means 70 for driving the left-right drive means 50 in the vertical direction.

  The left / right drive means 50 is a support arm 51 provided via a vertical drive means 70 on a traveling carriage (not shown) that moves along the welding direction, and a moving arm 53 supported by the support arm 51 via a left / right drive mechanism 52. The welding torch 20, the image acquisition means 30, and the shielding means 40 are integrally supported by the moving arm 53.

  Although details of the vertical driving means 70 are omitted, the support arm 51 is driven in the vertical direction with respect to the traveling carriage.

  The image acquisition means 30 includes an imaging means 31 such as a CCD camera, a groove preceding the welding torch 20 (hereinafter referred to as “preceding groove area”) and an illumination means 32 for illuminating the periphery thereof. For example, the light source 32a and the half mirror 32b are configured to illuminate the preceding groove region and its periphery with illumination light coaxial with the optical axis of the imaging unit 31. The imaging means 31 and the illumination means 32 are arranged in a housing 33 having an open lower end.

  The light shielding means 40 protrudes from the lower end of the main part 41 fixedly supported by the moving arm 53 of the left and right driving means 50, the light shielding plate 42 fixed to the main part 41, and vertically And a sliding shaft 43 configured to be slidable in a direction. The sliding shaft 43 is moved downward by a spring means such as a coil spring provided in the main portion 41, that is, in a direction in contact with the workpieces 81 and 82. It is energized. A sensor for detecting the position of the distal end portion 43 a of the sliding shaft 43 is built in the main portion 41. The sensor may be any sensor as long as it can detect the relative position of the sliding shaft 43 with respect to the main portion 41 and output it as an electrical signal. For example, a contact-type variable resistor such as a potentiometer, Various things such as a non-contact electromagnetic position sensor made of a magnet can be applied. The tip 43 of the sliding shaft 43 is constituted by a roller in order to reduce the resistance with the workpieces 81 and 82.

  The main portion 41 and the light shielding plate 42 are positioned so as to shield between the welding torch 20 and the image acquisition means 30, and in particular, the arc of the welding torch 20 and the light 20a of the molten pool (see the satin portion in FIG. 2). ) Is prevented from becoming disturbance light for the image acquisition means 30.

  With reference to the flowchart of FIG. 3, the operation of copying and welding the groove 80 where the two plate-like workpieces 81 and 82 are brought into contact with each other by the copying welding apparatus 10 will be described below.

  First, prior to copying welding, the groove 80 is temporarily fixed with 83, 83,... At an appropriate interval so that the two workpieces 81 and 82 are kept in contact with each other. To.

  First, the welding torch 20, the image acquisition unit 30, and the shielding unit 40 are supported on the moving arm 53 of the left and right driving unit 50 so that the positional relationship is a predetermined positional relationship, and the moving carriage, the vertical driving unit 70, The drive mechanism 52 is driven to align with the initial position of the welding groove 80.

  The copying operation is started with the initial alignment completed (step 1 (S1)). That is, while moving a movable carriage (not shown) along the direction in which the groove 80 extends, the left and right drive means 50 and the vertical drive means 70 are set in a driving state, and the copying operation is started by operating the control means 60.

  When the copying operation is started, first, line edge processing is performed in the upper detection area 110 (see FIG. 4) set in the upper part of the image 100 of the preceding groove area acquired by the image acquisition unit 30 (step 2 (S2)). . That is, a straight line indicated as a change from white to black is detected by scanning in the Y direction with an inclination of ± 3 degrees in the X direction in the area 110 as an allowable range.

  First, the scanning area 110 is set as a scanning area 110a in one direction (right direction in this example), and when the straight line 111a is detected in the detection area 110a (see FIG. 5), the area 110 is changed to Y. A detection area 110b whose direction is rotated 180 degrees is used, and a straight line is detected in the same manner as described above by scanning in the Y direction. When there is a groove 80 in the detection area 110b, a straight line 111b that is opposed to the straight line 111a and is substantially parallel to the straight line 111a is detected (see FIG. 6).

  When two substantially parallel straight lines 111a and 111b are detected in the upper detection area 110 by the above procedure (see FIG. 7), line detection is performed (YES) and the process proceeds to step 4 (S4). If the straight lines 111a and 111b are not detected, it is determined that no line is detected (NO), and the process returns to step 2 (S2).

  In step 4 (S4), a process is performed to determine whether or not temporary fixing is detected in the upper detection area 110. That is, the distance between the two straight lines 111a and 111b detected in step 2 (S2) is measured, and the distance between the two straight lines 111a and 111b is larger than a predetermined value in step 5 (S5). Whether or not is determined.

  Even when the temporary fixing bead 90 is in the upper detection area 110, the parallel straight lines 111a and 111b are detected in step 2 (S2) (see FIG. 8). However, the width of the temporary fixing bead 90 is extremely larger than that of the butt groove 80. Therefore, an appropriate value for distinguishing between the groove 80 and the temporary fixing bead 90 is set according to the width, and between the substantially parallel straight lines 111a and 111b detected in step 2 (S2). It is determined in step 5 (S5) whether or not the interval is larger than the predetermined value. If the interval is larger than the predetermined value, it is determined that the temporary fixing bead 90 has been detected (YES), and the process returns to step 2 (S2). If not, the temporary fixing bead 90 has not been detected (NO), and the process proceeds to step 6 (S6).

  From step 6 (S6) to step 9 (S9), a lower detection area 120 is set in the lower part of the screen 100, and line edge detection processing (step 6 (S6) is performed for the lower detection area 120). 2 (S2) is performed on the lower detection area 120, and the same determination as in step 3 (S3) is performed in step 7 (S7)), and the temporary fixing bead 90 is detected (step 8 (S8)). Step 4 (S4) is performed, step 9 (S9) is performed in the same manner as step 5 (S5)), and line detection is performed in the lower detection area 120 in step 7 (S7). If it is determined that the line is detected (YES), the process proceeds to step 8 (S8). If it is determined that the line is not detected (NO), the process returns to step 2 (S2). When it is determined in step 9 (S9) that the temporary fixing bead 90 is detected (YES), the process returns to step 2 (S2), and when the temporary fixing bead is not detected (NO), the process returns to step 10 (S10). move on.

  In step 10 (S10), an intermediate line 111c (121c) between the straight lines is calculated from the coordinates of the straight lines 111a (121a) and 111b (121b) detected in the upper detection area 110 and the lower detection area 120 ( (Refer to FIG. 9) The upper and lower line edges are set as the line edges, and the process proceeds to step 11 (S11).

  In step 11 (S11), an intermediate position 130 of the line connecting the upper and lower line edges 111c and 121c calculated in step 10 (S10) is calculated, and the intermediate position 130 is compared with the image center 100C (see FIG. 10). Proceed to step 12 (S12).

  In step 12 (S12), as a result of comparing the intermediate position 130 and the image center 100C, it is determined whether or not the intermediate position 130 is to the right of the image center 100C. The process proceeds to step 13 (S13), and when it is determined that the position is rightward (YES), the process proceeds to step 14 (S14).

  In step 13 (S13), as a result of comparing the intermediate position 130 and the image center 100C, it is determined whether or not the intermediate position 130 is to the left of the image center 100C. Returning to 2 (S2), when it is determined that the position is to the left (YES), the process proceeds to step 15 (S15).

  In step 14 (S14), a command to move the moving arm 53 to the left is issued to the left and right driving means 50, and the process returns to step 2 (S2).

  In step 15 (S15), a command to move the moving arm 53 to the right is issued to the left and right drive means 50, and the process returns to step 2 (S2).

  As described above, the welding torch 20 forms the weld bead while moving along the groove 80.

  In addition, when a deviation in the vertical direction, that is, the direction in which the workpieces 81 and 82 are separated from each other occurs between the front end of the welding torch 20 and the groove 80, the sliding means provided in the shielding means 40 slides. Since the tip 43a of the moving shaft 43 moves following the surfaces of the workpieces 81 and 82, this is detected by the sensor incorporated in the shielding means 40, and the control means 60 receives the detection result and the control means 60 moves up and down. To move the left and right drive means 50 up and down to adjust the position of the welding torch 20 (and the image acquisition means 30 and the light shielding plate 41 of the light shielding means 40) in the vertical direction.

  In the above-described profiling welding apparatus 10, the shape of the groove is not selected, and for example, the butt groove can be copied, which cannot be copied by irradiation with slit light, and the entire apparatus is configured in a small size. can do.

  It can be applied to various types of copy welding.

It is a perspective view which shows the outline | summary of embodiment of the profiling welding apparatus of this invention. It is a schematic side view. It is a flowchart which shows the operation | movement of copying welding. FIG. 5 to FIG. 10 show examples of the copying operation, and this figure shows a configuration example of an image acquired by the image acquisition means. FIG. 6 and FIG. 7 show a groove detection procedure, and this figure shows a state where a line edge is detected for a first straight line that limits the groove. It shows how a line edge is detected for a second straight line that defines a groove. It shows how a groove is detected. It shows a state of detecting a temporarily fixing bead. It shows a state in which a straight line passing between the coordinates of two straight lines is detected. The mode which detects the position shift of a groove | channel and a welding torch is shown.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 10 ... Copy welding apparatus, 20 ... Welding torch, 30 ... Image acquisition means, 31 ... Imaging means, 32 ... Illumination means, 40 ... Shielding means, 50 ... Left-right drive means, 60 ... Control means, 70 ... Vertical drive means, 80 ... groove, 100 ... image of preceding groove area

Claims (2)

A welding torch, image acquisition means for acquiring an image of a groove preceding the welding torch (hereinafter referred to as “preceding groove area”), and shielding means for shielding the welding torch from the preceding groove area; The left and right drive means for integrally supporting the welding torch, the image acquisition means and the shielding means and moving in the left and right direction, the position in the left and right direction of the groove from the image acquired by the image acquisition means, and the horizontal direction of the welding torch Control means for detecting a positional deviation from the position and controlling the position of the groove in the left-right direction and the position of the welding torch in the left-right direction by driving the left-right drive means based on the detection result. Ri formed a,
While having a vertical drive means for moving the left and right drive means in the vertical direction,
The shielding means includes a sensor for detecting a position of the tip portion, the tip portion contacting the workpiece being freely movable in a direction to be separated from and contacting the workpiece;
The control means drives the vertical drive means based on the detection result of the sensor, and controls the position so that the tip of the shielding means, the welding torch, and the image acquisition means maintain a predetermined positional relationship. Copy welding equipment characterized by the above. The image acquisition means includes an imaging means and an illumination means for illuminating the preceding groove area, and the illuminating means is configured to illuminate the preceding groove area with illumination light coaxial with the optical axis of the imaging means. The profiling welding apparatus according to claim 1, wherein:

Images