JP5801098B2 - Winding inspection apparatus and inspection method for metal can end - Google Patents

Description

  The present invention relates to a winding inspection apparatus and an inspection method for a metal can end for detecting, for example, a winding defect between a can body and a can lid of a beverage can.

  Conventionally, as a winding inspection apparatus for a metal can end, an inspection apparatus for detecting a tongue out defect or the like by photographing a lid portion of the can end and performing image analysis is known (for example, a patent) (See Reference 1.)

  In this inspection apparatus, a ring-type illumination device is disposed on the upper part of the winding portion of the can lid portion, and a TV camera is disposed on the same axis of the ring-type illumination device above the ring-type illumination device. . Then, the TV camera captures the upper end of the tightening portion of the can lid to obtain a ring-shaped image, and the ring width is measured from the center of the ring-shaped image radially at appropriate intervals.

  Thereby, when the said ring width dimension is larger than the preset threshold value, it is comprised so that it may determine with inferior goods.

Japanese Patent Laid-Open No. 7-218453

  However, in such a conventional inspection apparatus, the ring-shaped image of the upper end portion of the can lid is tightened and the ring width dimension taken is compared with a threshold value. In order to further improve the detection accuracy, it is necessary to measure not only the upper end of the winding but also the ring width dimension in the direction close to the can body.

  In this case, it is necessary to increase the number of cameras for photographing from both sides of the tightening of the can lid and to analyze a plurality of images, resulting in a complicated structure.

  The present invention has been made in view of such conventional problems, and an object of the present invention is to provide a winding inspection apparatus and inspection method for a metal can end that can accurately perform a winding inspection with a simple configuration. To do.

In order to solve the above-mentioned problem, in the winding inspection apparatus for a metal can end part according to claim 1 of the present invention, a camera and an illumination are arranged above the winding part of the can body, and the convex lens is mounted on the camera. In a metal can end tightening inspection device that detects a winding failure of the can body based on an image photographed through the camera, both the inner and outer side surfaces of the tightening portion projected by the convex lens are captured by the camera. A ring-shaped image acquisition unit that captures a ring-shaped image by photographing, a polar coordinate expansion unit that linearly expands the ring-shaped image acquired by the ring-shaped image acquisition unit, and a linear shape by the polar coordinate expansion unit The width from the inner edge indicating the inner edge of the inner band-like line corresponding to the inner side surface of the tightening portion to the outer edge indicating the outer edge of the outer band-like line corresponding to the outer side surface of the winding portion in the polar coordinate developed image Size Winding failure determining means for determining whether or not winding is in a predetermined threshold, and determining a winding failure by a change in the length direction of at least one of the width of the inner belt-like line and the width of the outer belt-like line; It is equipped with.

  That is, when detecting the winding failure of the can body, first, the inner and outer side surfaces of the winding portion of the can body are projected by a special optical body, photographed with a camera to obtain a ring-shaped image, The ring image is linearly expanded in a linear shape.

  And in this polar coordinate developed image, the outer edge showing the outer edge of the outer band line corresponding to the outer side surface of the winding part from the inner edge showing the inner edge of the inner band line corresponding to the inner side surface of the winding part. And determining whether or not the width dimension is within a predetermined threshold, and based on a change in the length direction of at least one of the width of the inner strip line and the width of the outer strip line, Determine.

  At this time, if the bulging portion is swollen or if the winding portion has a defect such as tongue out, the width dimension from the inner edge to the outer edge is outside a predetermined threshold. Such a winding failure is detected.

  In addition, when a bulge or a dent is generated in, for example, a part of the inner side surface of the tightening portion, the change in the length direction of the width of the inner strip line greatly varies. At this time, if a defect such as tongue sticking occurs on the inner side surface, even if the width dimension from the inner edge to the outer edge is within the threshold value, in the length direction of the width of the inner strip line. The change of fluctuates greatly.

  For this reason, by detecting that the change in the length direction of the width of the inner belt-like line or the change in the length direction of the width of the outer belt-like line is larger than a predetermined value, such a winding failure is prevented. Detected.

Moreover, in the winding inspection apparatus of the metal can end part of Claim 2, the said illumination was comprised by the ring illumination which is arrange | positioned coaxially with the said convex lens and illuminates the said both side surfaces of the said winding part.

  That is, ring illumination arranged coaxially with the special optical body is provided on the upper portion of the winding portion of the can body.

  For this reason, the outer side surface of the tightening portion is illuminated by light from a location close to the ring illumination, while the inner side surface of the winding portion is illuminated by light from the ring illumination located on the opposite side. Is done.

  Further, in the winding inspection apparatus for the end of the metal can according to claim 3, the winding failure determining means determines coordinates at equal intervals in an image obtained by linearly developing polar coordinates in the polar coordinate developing means, and the equal intervals. Based on the change in the difference in the width of each strip line measured at each of the coordinates, the winding end failure of the end of the can body is determined.

  In other words, the linearly developed polar coordinate image is determined at equal intervals, and based on the change in the difference in the width of each of the strip lines measured at the equally spaced coordinates, it is determined whether or not the end of the can has been tightened. Is done.

Further, in the winding tightening inspection method according to claim 4, a camera and an illumination are arranged above the winding portion of the can body, and the can body is inspected based on an image photographed by the camera via a convex lens . In a method for inspecting the end of a metal can that detects an incomplete winding, a ring-shaped image acquisition is performed in which both the inner and outer sides of the tightening portion projected by the convex lens are photographed with the camera to obtain a ring-shaped image. A polar coordinate development step of linearly developing the ring-shaped image acquired in the ring-shaped image acquisition step; and a polar coordinate development image linearly developed in the polar coordinate development step in the polar coordinate development step. Whether or not the width dimension from the inner edge indicating the inner edge of the inner band corresponding to the inner side surface to the outer edge indicating the outer edge of the outer band corresponding to the outer side surface of the tightening portion is within a predetermined threshold; and Above And a, a seaming defect determination step determines seaming defects due to changes in the length direction of the at least one width of the width of the side strip line outer strip line.

  That is, when detecting the winding failure of the can body, first, the inner and outer side surfaces of the winding portion of the can body are projected by a special optical body, photographed with a camera to obtain a ring-shaped image, The ring image is linearly expanded in a linear shape.

  And in this polar coordinate developed image, the outer edge showing the outer edge of the outer band line corresponding to the outer side surface of the winding part from the inner edge showing the inner edge of the inner band line corresponding to the inner side surface of the winding part. And determining whether or not the width dimension is within a predetermined threshold, and based on a change in the length direction of at least one of the width of the inner strip line and the width of the outer strip line, Determine.

  At this time, when the tightening portion swells or a dent is generated in the tightening portion, the width dimension from the inner edge to the outer edge is outside a predetermined threshold value, and such a tightening failure is detected. . Further, when a defect such as tongue sticking occurs in the tightening portion, the change in the width direction of the inner strip line or the change in the length direction of the outer strip line is more than a predetermined value. Since it becomes large, such a winding failure is detected.

  As described above, in the winding inspection apparatus for the end of the metal can according to claim 1 of the present invention, from the image of the camera provided above the can body, the winding of the winding portion such as bulge and tongue out A fastening failure can be detected, and a change in the length direction of the width of the inner belt-like line and a change in the length direction of the width of the outer belt-like line can be partially detected on the inner side surface and the outer side surface. Winding defects such as bulges, dents, and tongue out can be detected.

  In this way, since defects such as tongue out can be inspected from the image of the camera, compared with the case of adding a camera that acquires a side image of the can body, the analysis processing of multiple images and the complexity of the structure are caused. In addition, the winding tightening inspection can be accurately performed with a simple configuration.

  Moreover, in the winding inspection apparatus of the metal can end part of Claim 2, while being able to illuminate the outer side surface of the winding part of a can body with the light from the location which ring illumination adjoined, the inner side surface of the said winding part is The light from the ring illumination located on the opposite side can be illuminated.

  For this reason, compared with the case where the illumination which shines light on the said outer side surface and the said inner side surface is provided separately, cost reduction can be achieved.

  Further, in the winding inspection apparatus for the end of the metal can according to claim 3, the coordinates of the polar coordinates developed in a straight line are determined at equal intervals, and the widths of the respective strip lines measured at the equal intervals of the coordinates are determined. Based on the change in the difference, it is determined whether or not the end of the can has been tightened.

  Thereby, simplification and speeding up of image processing can be achieved.

  Further, in the winding tightening inspection method according to claim 4, the winding tightening portion can detect a winding tightening failure such as a bulge or a dent from the image of the camera provided above the can body, and the inner side. From the change in the length direction of the width of the band-like line and the change in the length direction of the width of the outer band-like line, it is possible to detect a defect such as tongue sticking generated in the tightening portion.

  In this way, since defects such as tongue out can be inspected from the image of the camera, compared with the case of adding a camera that acquires a side image of the can body, the analysis processing of multiple images and the complexity of the structure are caused. In addition, the winding tightening inspection can be accurately performed with a simple configuration.

1 is an overall configuration diagram showing an embodiment of the present invention. It is explanatory drawing which shows the winding fastening part of the embodiment, (a) is a figure which shows a normal state, (b) is a figure which shows the state which a part of winding fastening part swelled, (c) is winding. It is a figure which shows the state in which a part of fastening part was dented. It is explanatory drawing which shows the imaging | photography principle of the both sides | surfaces of the winding fastening part of the embodiment. It is a block diagram which shows the image processing apparatus of the embodiment. It is a flowchart which shows the operation | movement of the embodiment. It is explanatory drawing which shows the ring image image | photographed from the upper direction of the winding fastening part of the embodiment. It is explanatory drawing which shows the polar coordinate expansion | deployment image of the embodiment. It is explanatory drawing which shows the example of a defect of the winding fastening part of the embodiment.

  Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

  FIG. 1 is a view showing a metal can end tightening inspection apparatus 1 for carrying out the winding tightening inspection method according to the present embodiment. The winding tightening inspection apparatus 1 winds a can body 2 such as a beverage can. It is an apparatus for inspecting the fastening part 3.

  That is, the can body 2 such as a beverage can is made of metal, and includes a bottomed cylindrical can body portion 11 and a can lid portion 12 that forms the top surface of the can body portion 11. The can lid portion 12 is formed in a circular plate shape, and its peripheral portion 21 is bent upward along the upper edge portion 22 of the can body portion 11 as shown in FIG. Then, the upper end 22 of the can body 11 is folded back.

  Thereby, as shown in FIG. 1, the upper opening part of the said can body part 11 is closed by the said can lid part 12, and the said can body 2 is sealed.

  As shown in FIG. 1, the winding tightening inspection device 1 is configured to inspect the can body 2 in the inspection region 31. For example, when the can body 2 is installed on a belt conveyor to which the can body 2 is conveyed. Is configured to be able to inspect the can body 2 that is conveyed by the belt conveyor and that passes through the inspection region 31 of the winding tightening inspection apparatus 1. The winding tightening inspection apparatus 1 includes a camera 32 that images the can 2 in the inspection region 31 from above, and the imaging element of the camera 32 is constituted by a CCD.

  A convex lens 41, which is a special optical body, is disposed between the camera 32 and the can 2 in the inspection area 31. As shown in FIG. 3, the convex lens 41 has an outer diameter larger than the diameter of the can body 2 to be inspected, and the upper side where the spherical convex surface 42 is on the camera 32 side. It is arranged to face.

  A ring illumination 51 for illuminating light on the can body 2 is provided on the outer peripheral portion of the convex lens 41 and above the can body 2 disposed in the inspection region 31. Are arranged coaxially with the optical axis of the camera 32. The ring illumination 51 is formed in a circular ring shape, and the inner diameter of the ring illumination 51 is set larger than the outer diameter of the convex lens 41. Thereby, the image of the top of the can 2 can be acquired by the camera 32 via the ring illumination 51 and the convex lens 41.

  The ring illumination 51 is constituted by an LED illumination composed of a plurality of LEDs, and the ring illumination 51 irradiates light from the outer periphery of the can body 2 toward the center of the can body 2. It is configured. Thus, the upper portion of the can body 2 can be illuminated, and the tightening portion 3 erected on the periphery of the upper surface of the can body 2 has an inner side surface 61 on the inner side and an outer side surface 62 on the outer side. It is configured to be illuminated in its entirety.

  At this time, the inner surface reflected light 71 reflected by the inner side surface 61 is input to the camera 32 via the convex lens 41, and the outer surface reflected light 72 reflected by the outer side surface 62 is also refracted by the convex lens 41. It is configured to be input to the camera 32. Thereby, in the said camera 32, it is comprised so that the image of not only the said inner side surface 61 but the said outer side surface 62 of the said fastening part 3 can be acquired simultaneously.

  As shown in FIG. 1, the camera 32 for acquiring the image is connected to an image processing device 81, and the image processing device 81 is connected to an LED power source 82 that supplies power to the ring illumination 51. Has been. Accordingly, the illumination by the ring illumination 51 and the image acquisition by the camera 32 can be linked.

  As shown in FIG. 4, the image processing device 81 performs a process such as a captured image input unit 91 for inputting an image captured by the camera 32 and noise removal from the input image input by the captured image input unit 91. A screen processing unit 92 to perform, a polar coordinate development unit 93 for developing the processed image in polar coordinates, an edge detection unit 94 for detecting an edge portion from the polar coordinate development image developed by the polar coordinate development unit 93, and the edge detection unit 94 And an abnormality determination unit 95 that determines the presence or absence of an abnormality using the detection result obtained by.

  The operation of the present embodiment according to the above configuration will be described with reference to the flowchart shown in FIG.

  That is, when the CPU provided in the image processing apparatus 81 of the winding tightening inspection apparatus 1 starts the inspection process according to the program stored in the memory, the upper portion of the can body 2 provided upright in the inspection area 31. The image is taken by the camera 32, and the CCD image is inputted from the camera 32 (S1).

  At this time, the camera 32 is configured to acquire an image of the can 2 from above via the convex lens 41. For this reason, as described above, in addition to the image of the top portion of the tightening portion 3, the captured image includes the image of the inner side surface 61 and the image of the outer side surface 62 of the winding portion 3. Taken.

  As a result, as shown in FIG. 6, a ring image 101 in which an image of the tightening portion 3 including the inner side surface 61 and the outer side surface 62 is shown in a ring shape is acquired. Detecting the can lid center 102 of the can lid portion 12 (S2);

  Then, screen processing such as removing noise from the ring image 101 is performed (S3), with the can lid center 102 as the center, the winding part 3, the inner side surface 61 of the winding part 3, and the The donut-like region 111 including the outer side surface 62 of the winding part 3 is linearly developed in a linear shape, and a polar coordinate developed image 112 as shown in FIG. 7 is acquired (S4).

  In this polar coordinate developed image 112, an inner strip line 121 corresponding to the inner side surface 61 of the tightening portion 3 is shown. Therefore, the inner edge of the inner strip line 121 is detected and recognized as the inner flange edge 122. (S5). Further, since an outer belt-like line 123 corresponding to the outer side surface 62 of the tightening portion 3 is also shown, the outer edge of the outer belt-like line 123 is detected and recognized as the outer flange edge 124 (S6).

  Next, a width dimension 131 from the inner flange edge 122 to the outer flange edge 124 is calculated, and it is determined whether or not the width dimension 131 is within a predetermined threshold value (S8).

  Specifically, in the polar coordinate development image 112, measurement coordinates 141,... Are set at equal intervals in the extending direction of the strip lines 121, 123. Then, the width dimension 131 from the inner flange edge 122 to the outer flange edge 124 is calculated at the equally spaced measurement coordinates 141,..., And the calculated width dimension 131 is a predetermined threshold value. It is judged whether it is in (S8).

  As this threshold value, it is comprised by the preset upper limit value and lower limit value, and as shown to (a) of FIG. 2, the upper edge part 22 of the said can body part 11 is by the peripheral part 21 of the said can lid part 12. In the state of being properly wound, the width dimension 131 from the inner flange edge 122 to the outer flange edge 124 is set to be within a range between the lower limit value and the upper limit value. For this reason, it is determined that there is no abnormality in the inspection in step S8, and the process proceeds to next step S9.

  On the other hand, as shown in FIGS. 2B and 2C, the peripheral edge of the can lid 12 that wraps around the upper edge of the can body 11 is swollen, or due to turbulence, FIG. As shown in FIG. 8, when a so-called tongue-out 151 in which a part of the can body 11 protrudes from the tightening portion 3 has occurred, the inner flange edge 122 to the outer flange edge 124 are The width dimension 131 exceeds the upper limit value and deviates from the threshold value.

  In this case, it is determined that there is an abnormality in the inspection in step S8. For example, the winding failure flag set in the memory is set from “0” to “1” (S10), and the inspection processing routine is completed. To do.

  In step S8, when it is determined that the width dimension 131 is within the threshold (S8), the length of the inner band width 161 indicating the width of the inner band-like line 121 in the polar coordinate developed image 112. The amount of change in the direction and the amount of change in the length direction of the outer band width 162 indicating the width of the outer band line 123 are inspected (S9).

  More specifically, the band widths 161 and 162 of the band-like lines 121 and 123 are measured at the measurement coordinates 141,... Set at equal intervals as described above, and the band-like lines at various places are measured. Based on the magnitude of the change in the difference between the band widths 161 and 162 at 121 and 123, the winding failure at the end of the can body 2 is determined.

  For example, when the difference between the maximum value and the minimum value of the band widths 161 and 162 measured at the respective locations exceeds a predetermined value, it is determined that the winding is defective.

  At this time, as shown in (b) of FIG. 2, when a bulge occurs in a part of the outer side surface 62 of the tightening portion 3, the outer band width 162 of the outer band-like line 123 is The outer band-like line 123 becomes extremely large in a part in the length direction. Further, as shown in FIG. 2 (c), when a dent is formed on a part of the outer side surface 62 of the tightening portion 3, the outer band width 162 of the outer band line 123 is A part of the outer belt-like line 123 in the length direction becomes extremely small.

  When the tongue 151 is formed on the outer side surface 62, the outer band width 162 of the outer band-like line 123 becomes extremely large in a part of the outer band-like line 123 in the length direction. For this reason, even if the width dimension 131 from the inner flange edge 122 to the outer flange edge 124 is within the threshold value, the change in the length direction of the width of the outer strip line 123 varies greatly. This can be detected as an abnormality.

  Thus, when the change in the length direction of the outer belt width 162 of the outer belt-like line 123 changes greatly, or when the change in the length direction of the inner belt width 161 of the inner belt-like line 121 changes greatly. Is judged that there is an abnormality in the inspection in step S9, for example, by setting the winding tightening flag set in the memory from “0” to “1” (S10), and the inspection processing routine is finished. On the other hand, if no abnormality is detected in step S9, the winding failure flag is reset to “0” (S11), and the inspection processing routine is terminated.

  As described above, the image acquired by the camera 32 provided above the can body 2 can detect the swell of the tightening portion 3 and the winding failure such as the tongue 151, and the inner belt-like shape. From the change in the length direction of the inner belt width 161 of the line 121 and the change in the length direction of the outer belt width 162 of the outer belt-like line 123, the partial bulge in the inner side surface 61 and the outer side surface 62 It is possible to detect a winding failure such as a dent and tongue sticking 151.

  As described above, since defects such as the tongue 151 can be inspected from the image of the camera 32, the analysis processing of multiple images and the complexity of the structure are complicated as compared with the case where a camera for acquiring the side image of the can body 2 is added. The winding tightening inspection can be performed with high accuracy with a simple configuration without incurring a reduction in the size.

  In the present embodiment, as shown in FIG. 3, the outer side surface 62 of the tightening portion 3 can be obtained by using the ring illumination 51 arranged coaxially with the optical axis of the camera 32. It can illuminate with the light from the location which the ring illumination 51 adjoined. On the other hand, the inner side surface 61 of the tightening portion 3 can be illuminated with light from the ring illumination 51 located on the opposite side.

  For this reason, compared with the case where the illumination which shines light on the said outer side surface 62 and the said inner side surface 61 is provided separately, cost reduction can be achieved.

  And the polar coordinate expansion | deployment image 112 which carried out the polar coordinate expansion | distribution to linear form changes to the difference change of each strip | belt width 161,162 in each said strip | belt-shaped line 121,123 in the measurement coordinate 141, ... set to equal intervals. Based on this, it is possible to determine a winding failure at the end of the can body 2.

  Thereby, compared with the case where the difference change of each band width 161, 162 of each said strip | belt-shaped line 121,123 is test | inspected over the whole area, simplification and speeding-up of image processing can be achieved.

  In the present embodiment, a CCD is used as the image pickup element of the camera 32, but a CMOS may be used.

  In the present embodiment, the inner band width 151 of the inner band line 121 corresponding to the inner side surface 61 of the tightening portion 3 and the outer side surface 62 of the polar coordinate development image 112 linearly developed in polar coordinates. The winding failure was determined by looking at the change between the outer belt-like line 123 and the outer belt width 162. However, the present invention is not limited to this, and the change in one of the belt widths 151 and 162 is seen. You may determine a winding fault.

  Further, in the present embodiment, the case where the light source of the ring illumination 51 is configured by LED illumination has been described. However, the present invention is not limited to this and may be replaced by another visible light.

DESCRIPTION OF SYMBOLS 1 Tightening inspection apparatus 2 Can body 3 Tightening part 32 Camera 51 Ring illumination 61 Inner side surface 62 Outer side surface 81 Image processing apparatus 101 Ring image 112 Polar coordinate expansion image 121 Inner strip line 122 Inner flange edge 123 Outer strip line 124 Outer flange edge 131 Width Dimension 161 Inner Band Width 162 Outer Band Width

Claims (4)

A winding inspection device for a metal can end detecting a winding failure of the can body based on an image photographed through a convex lens on the camera by arranging a camera and illumination above the winding portion of the can body In
A ring-shaped image acquiring means for capturing a ring-shaped image by photographing both inner and outer side surfaces of the tightening portion projected by the convex lens with the camera;
Polar coordinate expansion means for linearly expanding the ring-shaped image acquired by the ring-shaped image acquisition means;
In the polar coordinate development image linearly developed by the polar coordinate development means, the outer belt-like line corresponding to the outer side surface of the tightening portion from the inner edge indicating the inner edge of the inner belt-like line corresponding to the inner side surface of the tightening portion. Winding failure due to whether or not the width dimension to the outer edge indicating the outer edge is within a predetermined threshold, and the change in the length direction of at least one of the width of the inner strip line and the width of the outer strip line Winding tightening determination means for determining,
A winding inspection apparatus for a metal can end characterized by comprising: The winding inspection apparatus for a metal can end according to claim 1, wherein the illumination is configured by ring illumination that is arranged coaxially with the convex lens and illuminates the both side surfaces of the tightening portion.   The winding failure determination means determines coordinates at equal intervals in the image obtained by linearly developing polar coordinates in the polar coordinate developing means, and based on the difference in width difference in each of the strip lines measured at the equally spaced coordinates. 3. A winding inspection apparatus for a metal can end according to claim 1 or 2, wherein a winding tightening failure at the end of the can body is determined. A winding inspection method for the end of a metal can, in which a camera and an illumination are arranged above the winding portion of the can body, and the winding failure of the can body is detected based on an image taken by the camera via a convex lens. In
A ring-shaped image acquisition step of capturing a ring-shaped image by photographing both inner and outer side surfaces of the tightening portion projected by the convex lens with the camera;
A polar coordinate development step for linearly developing the ring-shaped image acquired in the ring-shaped image acquisition step;
In the polar coordinate development image linearly developed in the polar coordinate development stage, the outer belt-like line corresponding to the outer side surface of the tightening portion from the inner edge indicating the inner edge of the inner belt-like line corresponding to the inner side surface of the tightening portion. Winding failure due to whether or not the width dimension to the outer edge indicating the outer edge is within a predetermined threshold, and the change in the length direction of at least one of the width of the inner strip line and the width of the outer strip line Winding tightening defect determination stage for determining,
A method for inspecting the end of a metal can.

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